Aims. Pelvic discontinuity is a challenging acetabular defect without a consensus on surgical management. Cup-cage reconstruction is an increasingly used treatment strategy. The present study evaluated implant survival, clinical and radiological outcomes, and complications associated with the cup-cage construct. Methods. We included 53 cup-cage construct (51 patients) implants used for hip revision procedures for pelvic discontinuity between January 2003 and January 2022 in this retrospective review. Mean age at surgery was 71.8 years (50.0 to 92.0; SD 10.3), 43/53 (81.1%) were female, and mean follow-up was 6.4 years (0.02 to 20.0; SD 4.6). Patients were implanted with a Trabecular Metal Revision Shell with either a ZCA cage (n = 12) or a TMARS cage (n = 40, all Zimmer Biomet). Pelvic discontinuity was diagnosed on preoperative radiographs and/or intraoperatively. Kaplan-Meier survival analysis was performed, with failure defined as revision of the cup-cage reconstruction. Results. The five-year all-cause survival for cup-cage reconstruction was 73.4% (95% confidence interval (CI) 61.4 to 85.4), while the ten- and 15-year survival was 63.7% (95% CI 46.8 to 80.6). Survival due to aseptic loosening was 93.4% (95% CI 86.2 to 100.0) at five, ten, and 15 years. The rate of revision for aseptic loosening, infection, and dislocation was 3/53 (5.7%), 7/53 (13.2%), and 6/53 (11.3%), respectively. The mean leg length discrepancy improved (p < 0.001) preoperatively from a mean of 18.2 mm (0 to 80; SD 15.8) to 7.0 mm (0 to 35; SD 9.8) at latest follow-up. The horizontal and vertical hip centres improved (p < 0.001) preoperatively from a mean of 9.2 cm (5.6 to 17.5; SD 2.3) to 10.1 cm (6.2 to 13.4; SD 2.1) and 9.3 cm (4.7 to 15.8; SD 2.5) to 8.0 cm (3.7 to 12.3; SD 1.7), respectively. Conclusion. Cup-cage reconstruction provides acceptable outcomes in the management of pelvic discontinuity. One in four constructs undergo revision within five years, most commonly for periprosthetic joint infection, dislocation, or aseptic loosening. Cite this article: Bone Joint J 2024;106-B(5 Supple B):66–73

Aims. Pelvic discontinuity is a rare but increasingly common complication of total hip arthroplasty (THA). This single-centre study evaluated the performance of custom-made triflange acetabular components in acetabular reconstruction with pelvic discontinuity by determining: 1) revision and overall implant survival rates; 2) discontinuity healing rate; and 3) Harris Hip Score (HHS). Methods. Retrospectively collected data of 38 patients (39 hips) with pelvic discontinuity treated with revision THA using a custom-made triflange acetabular component were analyzed. Minimum follow-up was two years (mean 5.1 years (2 to 11)). Results. There were eight subsequent surgical interventions. Two failures (5%) of the triflange acetabular components were both revised because of deep infection. There were seven (18%) patients with dislocation, and five (13%) of these were treated with a constraint liner. One patient had a debridement, antibiotics, and implant retention (DAIR) procedure. In 34 (92%) hips the custom-made triflange component was considered stable, with a healed pelvic discontinuity with no aseptic loosening at midterm follow-up. Mean HHS was 80.5 (48 to 96). Conclusion. The performance of the custom triflange implant in this study is encouraging, with high rates of discontinuity healing and osteointegration of the acetabular implant with no aseptic loosening at midterm follow-up. However, complications are not uncommon, particularly instability which we successfully addressed with constrained liners. Cite this article: Bone Jt Open 2022;3(11):867–876

Aims. The aim of this study was to compare the biomechanical models of two frequently used techniques for reconstructing severe acetabular defects with pelvic discontinuity in revision total hip arthroplasty (THA) – the Trabecular Metal Acetabular Revision System (TMARS) and custom triflange acetabular components (CTACs) – using virtual modelling. Methods. Pre- and postoperative CT scans from ten patients who underwent revision with the TMARS for a Paprosky IIIB acetabular defect with pelvic discontinuity were retrospectively collated. Computer models of a CTAC implant were designed from the preoperative CT scans of these patients. Computer models of the TMARS reconstruction were segmented from postoperative CT scans using a semi-automated method. The amount of bone removed, the implant-bone apposition that was achieved, and the restoration of the centre of rotation of the hip were compared between all the actual TMARS and the virtual CTAC implants. Results. The median amount of bone removed for TMARS reconstructions was significantly greater than for CTAC implants (9.07 cm. 3. (interquartile range (IQR) 5.86 to 21.42) vs 1.16 cm. 3. (IQR 0.42 to 3.53) (p = 0.004). There was no significant difference between the median overall implant-bone apposition between TMARS reconstructions and CTAC implants (54.8 cm. 2. (IQR 28.2 to 82.3) vs 56.6 cm. 2. (IQR 40.6 to 69.7) (p = 0.683). However, there was significantly more implant-bone apposition within the residual acetabulum (45.2 cm. 2. (IQR 28.2 to 72.4) vs 25.5 cm. 2. (IQR 12.8 to 44.1) (p = 0.001) and conversely significantly less apposition with the outer cortex of the pelvis for TMARS implants compared with CTAC reconstructions (0 cm. 2. (IQR 0 to 13.1) vs 23.2 cm. 2. (IQR 16.4 to 30.6) (p = 0.009). The mean centre of rotation of the hip of TMARS reconstructions differed by a mean of 11.1 mm (3 to 28) compared with CTAC implants. Conclusion. In using TMARS, more bone is removed, thus achieving more implant-bone apposition within the residual acetabular bone. In CTAC implants, the amount of bone removed is minimal, while the implant-bone apposition is more evenly distributed between the residual acetabulum and the outer cortex of the pelvis. The differences suggest that these implants used to treat pelvic discontinuity might achieve short- and long-term stability through different biomechanical mechanisms. Cite this article: Bone Joint J 2024;106-B(5 Supple B):74–81

The use of ilioischial cage reconstruction for pelvic discontinuity has been replaced by the Trabecular Metal (Zimmer, Warsaw, Indiana) cup-cage technique in our institution, due to the unsatisfactory outcome of using a cage alone in this situation. We report the outcome of 26 pelvic discontinuities in 24 patients (20 women and four men, mean age 65 years (44 to 84)) treated by the cup-cage technique at a mean follow-up of 82 months (12 to 113) and compared them with a series of 19 pelvic discontinuities in 19 patients (18 women and one man, mean age 70 years (42 to 86)) treated with a cage at a mean follow-up of 69 months (1 to 170). The clinical and radiological outcomes as well as the survivorship of the groups were compared. In all, four of the cup-cage group (15%) and 13 (68%) of the cage group failed due to septic or aseptic loosening. The seven-year survivorship was 87.2% (95% confidence interval (CI) 71 to 103) for the cup-cage group and 49.9% (95% CI 15 to 84) for the cage-alone group (p = 0.009). There were four major complications in the cup-cage group and nine in the cage group. Radiological union of the discontinuity was found in all successful cases in the cup-cage group and three of the successful cage cases. Three hips in the cup-cage group developed early radiological migration of the components, which stabilised with a successful outcome. Cup-cage reconstruction is a reliable technique for treating pelvic discontinuity in mid-term follow-up and is preferred to ilioischial cage reconstruction. If the continuity of the bone graft at the discontinuity site is not disrupted, early migration of the components does not necessarily result in failure. Cite this article: Bone Joint J 2014;96-B:195–200

Aims. Severe acetabular bone loss and pelvic discontinuity (PD) present particular challenges in revision total hip arthroplasty. To deal with such complex situations, cup-cage reconstruction has emerged as an option for treating this situation. We aimed to examine our success in using this technique for these anatomical problems. Patients and Methods. We undertook a retrospective, single-centre series of 35 hips in 34 patients (seven male, 27 female) treated with a cup-cage construct using a trabecular metal shell in conjunction with a titanium cage, for severe acetabular bone loss between 2011 and 2015. The mean age at the time of surgery was 70 years (42 to 85) and all patients had an acetabular defect graded as Paprosky Type 2C through to 3B, with 24 hips (69%) having PD. The mean follow-up was 47 months (25 to 84). Results. The cumulative five-year survivorship of the implant with revision for any cause was 89% (95% confidence interval (CI) 72 to 96) with eight hips at risk. No revision was required for aseptic loosening; however, one patient with one hip (3%) required removal of the ischial flange of the cage due to sciatic nerve irritation. Two patients (6%; two hips) suffered from hip dislocation, whereas one patient (one hip) required revision surgery with cement fixation of a dual-mobility acetababular component into a well-fixed cup-cage construct. Two patients (6%; two hips) developed periprosthetic infection. One patient was successfully controlled with a two-stage revision surgery, while the other patient underwent excision arthroplasty due to severe medical comorbidities. For the whole series, the Harris Hip Score significantly improved from a mean of 30 (15 to 51) preoperatively to 71 (40 to 89) at the latest follow-up (p < 0.001). Conclusion. Our findings suggest that cup-cage reconstruction is a viable option for major segmental bone defects involving the posterior column and PD. It allows adequate restoration of the acetabulum centre with generally good stability and satisfactory postoperative function. Instability and infection remain drawbacks in these challenging revision cases. Cite this article: Bone Joint J 2018;100-B:1442–48

Pelvic discontinuity is a separation through the acetabulum with the ilium displacing superiorly and the ischium/pubis displacing inferiorly. This is a biomechanically challenging environment with a high rate of failure for standard acetabular components. The cup-cage reconstruction involves the use of a highly porous metal cup to achieve biological bone ingrowth on both sides of the pelvic discontinuity and an ilioischial cage to provide secure fixation across the discontinuity and bring the articulating hip center to the correct level. The purpose of this study was to report long term follow up of the use of the cup-cage to treat pelvic discontinuity. All hip revision procedures between January 2003 and January 2022 where a cup-cage was used for a hip with a pelvic discontinuity were included in this retrospective review. All patients received a Trabecular Metal Revision Shell with either a ZCA cage or TMARS cage (Zimmer-Biomet Inc.). Pelvic discontinuity was diagnosed on pre-operative radiographs and/or intraoperatively. Kaplan-Meier survival analysis was performed with failure defined as revision of the cup-cage reconstruction. Fifty-seven cup-cages in 56 patients were included with an average follow-up of 6.25 years (0.10 to 19.98 years). The average age of patients was 72.09 years (43 to 92 years) and 70.2% of patients were female. The five year Kaplan-Meier survival was 92.0% (95% CI 84.55 to 99.45) and the ten year survival was 80.5% (95% CI 58.35 to 102.65). There were 5 major complications that required revision of the cup-cage reconstruction (3 infections and 2 mechanical failures). There were 9 complications that required re-operation without revision of the cup-cage reconstruction (5 dislocations, 3 washouts for infection and one femoral revision for aseptic loosening). In our hands the cup-cage reconstruction has provided a reliable tool to address pelvic discontinuity with an acceptable complication rate

Pelvic discontinuity represents a rare but challenging problem for orthopaedic surgeons. It is most commonly encountered during revision total hip replacement, but can also result from an iatrogentic acetabular fracture during hip replacement. The general principles in management of pelvic discontinuity include restoration of the continuity between the ilium and the ischium, typically with some form of plating. Bone grafting is frequently required to restore pelvic bone stock. The acetabular component is then impacted, typically using an uncemented, trabecular metal component. Fixation with multiple supplemental screws is performed. For larger defects, a so-called ‘cup–cage’ reconstruction, or a custom triflange implant may be required. Pre-operative CT scanning can greatly assist in planning and evaluating the remaining bone stock available for bony ingrowth. Generally, good results have been reported for constructs that restore stability to the pelvis and allow some form of biologic ingrowth. Cite this article: Bone Joint J 2013;95-B, Supple A:109–13

Pelvic discontinuity is defined as a separation of the ilium superiorly from the ischiopubic segment inferiorly. In 2018, the main management options include the following: 1) hemispheric acetabular component with posterior column plating, 2) cup-cage construct, 3) pelvic distraction, and 4) custom triflange construct. A hemispheric acetabular component with posterior column plating is a good option for acute pelvic discontinuities. However, healing potential is dependent on host's biology and characteristic of the discontinuity. The plate should include 3 screws above and 3 screws below the discontinuity with compression in between. In addition, the hemispherical acetabular component should have at least 50% host bone contact with 3–4 screws superior and 2–3 screws inferior to the discontinuity. On the other hand, a cup-cage construct can be used in any pelvic discontinuity. This includes a highly porous acetabular component placed on remaining host bone. Occasionally, highly porous metal augments are used to fill the remaining bone defects. A supplemental cage is placed over the acetabular component, spanning the discontinuity from the ilium to the ischium. A polyethylene liner is then cemented into place with antibiotic-loaded bone cement. Rarely, pelvic distraction may be needed. With this technique, pelvic stability is obtained via distraction of the discontinuity by elastic recoil of the pelvis and by fixing the superior hemipelvis and inferior hemipelvis to a highly porous metal cup or augment with screws, thereby unitizing the superior and inferior aspects of the pelvis. In essence, the cup acts as a segmental replacement of the acetabulum, with healing occurring to the cup or augment, resulting in a unitised hemipelvis. Frequently, the discontinuity itself does not achieve bony healing. Finally, custom triflange constructs are being utilised with increasing frequency. Triflange cups are custom-designed, porous and/or hydroxyapatite coated, titanium acetabular components with iliac, ischial, and pubic flanges. Rigid fixation promotes healing of the discontinuity and biologic fixation of the implant. It requires a CT scan, dedicated preoperative design, and fabrication costs

Aims. The aim of this study was to assess the clinical and radiological results of patients who were revised using a custom-made triflange acetabular component (CTAC) for component loosening and pelvic discontinuity (PD) after previous total hip arthroplasty (THA). Methods. Data were extracted from a single centre prospective database of patients with PD who were treated with a CTAC. Patients were included if they had a follow-up of two years. The Hip Disability and Osteoarthritis Outcome Score (HOOS), modified Oxford Hip Score (mOHS), EurQol EuroQoL five-dimension three-level (EQ-5D-3L) utility, and Numeric Rating Scale (NRS), including visual analogue score (VAS) for pain, were gathered at baseline, and at one- and two-year follow-up. Reasons for revision, and radiological and clinical complications were registered. Trends over time are described and tested for significance and clinical relevance. Results. A total of 18 females with 22 CTACs who had a mean age of 73.5 years (SD 7.7) were included. A significant improvement was found in HOOS (p < 0.0001), mOHS (p < 0.0001), EQ-5D-3L utility (p = 0.003), EQ-5D-3L NRS (p = 0.013), VAS pain rest (p = 0.008), and VAS pain activity (p < 0.0001) between baseline and final follow-up. Minimal clinically important improvement in mOHS and the HOOS Physical Function Short Form (HOOS-PS) was observed in 16 patients (73%) and 14 patients (64%), respectively. Definite healing of the PD was observed in 19 hips (86%). Complications included six cases with broken screws (27%), four cases (18%) with bony fractures, and one case (4.5%) with sciatic nerve paresthesia. One patient with concurrent bilateral PD had revision surgery due to recurrent dislocations. No revision surgery was performed for screw failure or implant breakage. Conclusion. CTAC in patients with THA acetabular loosening and PD can result in stable constructs and significant improvement in functioning and health-related quality of life at two years' follow-up. Further follow-up is necessary to determine the mid- to long-term outcome. Cite this article: Bone Jt Open 2023;4(2):53–61

This report reviews the long-term results of treating acetabula with unusually severe problems, such as pelvic discontinuity or major column loss after failed total hip arthroplasty (THA) and reconstruction problems. Loss of acetabular bone stock results from removal of bone during the original procedure, prosthetic failure, and osteolysis. In massive structural failure, the acetabular rim, quadrilateral plate, and associated columns become deficient. At worst, this may be combined with pelvic discontinuity and disruption of the ilium and ischium. Prosthetic protrusio may result from fixation loss and be associated with scarring of the femoral vessels, femoral nerve, ureter and bowel. A variety of implants has been used to in ace-tabular reconstruction. The results are often poor because of insufficient bone stock to support the implant. In a consecutive series of 251 THA revisions done between 1988 and 1996, 17 patients were treated for major pelvic column loss, pelvic discontinuity or both. In five patients, a posterolateral approach without trochanteric osteotomy was used. The extensile triradiate approach with ilioinguinal extension was used in 12 patients in whom severe prosthetic protrusio increased the risk of intrapelvic iatrogenic injury. A long anterior column pelvic plate was applied. A posteriorly placed AO 4.5-mm pelvic reconstruction plate with 10 to 12 holes was used in nine cases of pelvic discontinuity and in five cases of posterior column bone loss. This plate extended from the most inferior extent of the ischium across the wall of the posterior column to a point high on the ilium. Anterior column fixation was done in eight of nine cases of pelvic discontinuity and all three cases of anterior column deficiency. This called for an 8 to 12-hole 3.5-mm AO pelvic reconstruction plate that extended from the pubic symphysis across the pelvic rim. This spanned the anterior column defect, ranging from 4 cm to 8 cm, to the medial wall of the ilium. Bulk allograft was used in 16 of the 17 patients. The patient in whom allograft was not used had pelvic discontinuity following pelvic irradiation. Whole pelvic acetabular transplants were used in seven with severe bone loss or following resection for chondrosarcoma and the other for pigmented or villonodular synovitis. Posterior segmental acetabular allograft was used in two cases of posterior column absence. Femoral heads were used in two posterior column defects, three pelvic discontinuities with anterior column defect, and two anterior column defects. Acetabular components were cemented in six of seven whole bulk ace-tabular transplants, six of nine pelvic discontinuities and two anterior column defects. Cemented implants were classified as loose if there was a complete radiolucent line at the bone cement interface, measurable component migration or measurable change in position. Uncemented acetabular components were considered loose if component migration had occurred or screws had broken. Pelvic plates were considered loose if there was measurable migration or change in plate position or if fixation screws had backed out or broken. Radiographic union was considered present when bridging callus or trabecular bone was visible across the discontinuity site. Junctional healing was considered probable when radiographs did not show obvious signs of failure. Grafts were considered unhealed if there was obvious displacement, bone gaps or hardware breakage. Seven of the nine patients with pelvic discontinuity had late evidence of healing of the fracture and allograft consolidation. One underwent removal of the graft at three weeks after developing acute postoperative infection: early junctional healing of a whole bulk acetabular allograft required an osteotomy to break up the interface. Another patient, who underwent removal of the graft and implant at three months for chronic infection, had consolidation of a whole bulk ace-tabular allograft. One patient underwent revision of a pressfitted acetabular component at 60 months, and the pelvic discontinuity was solidly united. In a fourth patient, explored at 124 months for loosening of a cemented cup, there was near complete dissolution of the graft posterior acetabular wall and a loose posterior pelvic plate. In a patient with pelvic discontinuity after radiation therapy for uterine carcinoma, satisfactory healing of the pelvic discontinuity was confirmed at 32 months, when excisional arthroplasty for late chronic infection followed urinary sepsis. Seven patients had major column loss with severe cavitary defects. Consolidation of the allograft was noted in all seven within the first 12 months of follow-up. Revision (47%) was required for infection in three patients, implant loosening in four, and recurrent implant dislocation in one. The four loose cups were revised to a cemented all-polyethylene component. All four implants had been placed on less than 50% host bone. None of the four has required subsequent revision. Dislocation postoperatively occurred in eight patients. In six, the extensile triradiate approach had been used. This approach led to dislocation in 50%. The main reasons for using the extensile triradiate approach were to avoid catastrophic injuries by direct exposure of vital structures and to allow stable anterior column plate fixation. In that no neurovascular injuries occurred and stable durable allograft consolidation and healing of pelvic discontinuity took place, these goals were largely met. Three patients developed late sciatic palsy. In one, plaster immobilisation had possibly caused direct pressure over the fibular head and led to chronic peroneal palsy. The other two underwent additional exploration of the sciatic nerve for late entrapment caused by migration of screws from the posterior column plate. Two patients developed bladder infections postoperatively. Another developed superficial phlebitis of the lower leg. Acetabular revision for loosening was necessary in three of seven cementless implants, while only two of 10 cemented implants failed. The acetabular component should be cemented into the allograft when more than 50% of the prosthetic interface is non-viable. Virtually all graft material, including dense cortical grafts, may ultimately fail if used for implant fixation. Patients should be told about the inevitable risks. However, techniques used led to stable healing of the pelvic discontinuity in most cases. Long pelvic plates that securely stabilise the pelvis and allografts carefully opposed to host bone may explain the relative success in this series

Stabilisation of a pelvic discontinuity with a posterior column plate with or without an associated acetabular cage sometimes results in persistent micromotion across the discontinuity with late fatigue failure and component loosening. Acetabular distraction offers an alternative technique for reconstruction in cases of severe bone loss with an associated pelvic discontinuity. We describe the technique of acetabular distraction with porous tantalum components and evaluate its survival, function and complication rate in patients undergoing revision surgery for chronic pelvic discontinuity. Between 2002 and 2006, we treated 28 patients with a chronic pelvic discontinuity acetabular reconstruction using acetabular distraction. A porous tantalum elliptical acetabular component was used alone or with an associated modular porous tantalum augment in all patients. Three patients died and five patients were lost to follow-up before two years. The remaining twenty patients were followed semiannually for a minimum of two years (average, 4.5 years; range, 2–7 years) with clinical pain and walking scores as well as radiographic evaluation for loosening, migration or failure. In the remaining twenty patients available for follow-up, one patient did require re-revision for aseptic loosening. Fifteen patients remained radiographically stable at last follow-up. Four patients had early migration of their acetabular component but thereafter remained radiographically stable and clinically asymptomatic. The average improvement using the modified Merle d'Aubigne – Postel pain and ambulation score was 6.6 (range, 3.3–9.6). There were no postoperative dislocations; however, we did encounter one infection, one vascular injury and one bowel injury. In this series, the use of acetabular distraction with porous tantalum components provides a biologic alternative to cage constructs with more predictable clinical results (average follow-up 4.5 years) for reconstruction of severe acetabular defects with associated pelvic discontinuity

Stabilisation of a chronic pelvic discontinuity with a posterior column plate with or without an associated acetabular cage sometimes results in persistent micromotion across the discontinuity with late fatigue failure and component loosening. We believe that these chronic discontinuities are really chronic fracture non-unions incapable of healing. Acetabular distraction offers an alternative technique for reconstruction in cases of severe bone loss with an associated pelvic discontinuity. We describe the technique of acetabular distraction with porous tantalum components and evaluate its survival, function and complication rate in patients undergoing revision surgery for chronic pelvic discontinuity. Between 2002 and 2006, we treated 28 patients with a chronic pelvic discontinuity acetabular reconstruction using acetabular distraction. A porous tantalum elliptical acetabular component was used alone or with an associated modular porous tantalum augment in all patients. Three patients died and five patients were lost to follow up before two years. The remaining twenty patients were followed semiannually for a minimum of two years (average, 5.5 years; range, 2–9 years) with clinical pain and walking scores as well as radiographic evaluation for loosening, migration or failure. In the remaining twenty patients available for follow up, one patient did require re-revision for aseptic loosening. Fifteen patients remained radiographically stable at last follow up. Four patients had early migration of their acetabular component but thereafter remained radiographically stable and clinically asymptomatic. The average improvement using the modified Merle d'Aubigne – Postel pain and ambulation score was 6.6 (range, 3.3–9.6). There were no post-operative dislocations; however, we did encounter one infection, one vascular injury and one bowel injury. In this series, the use of acetabular distraction with porous tantalum components provides a biologic alternative to cage constructs with more predictable clinical results (average follow up 5.5 years) for reconstruction of severe acetabular defects with associated pelvic discontinuity

Introduction. During revision total hip arthroplasty, successful treatment of acetabular bone loss with an associated chronic pelvic discontinuity is dependent upon the remaining bone stock, stability of the construct, potential for biologic fixation, and healing of the discontinuity. Several techniques have been described for the treatment of this clinical entity; the authors recommend the use of acetabular distraction technique in conjunction with a jumbo cup with or without augments. The authors recently evaluated the minimum two-year follow-up of acetabular distraction technique for the treatment of chronic pelvic discontinuity. In the process, a chronic pelvic discontinuity classification was created based on the type of reconstruction required. The purpose of this study is to introduce the initial observations of this novel classification system. Methods. Patients from two academic institutions undergoing acetabular distraction for chronic pelvic discontinuity were identified between January 2002 and December 2013 with minimum 2-year follow-up. Radiographs at latest follow-up were compared to serial radiographs from the index surgery. Data was collected by chart review in accordance with institutional IRB protocol from both institutions. Results. A cohort of 32 patients had minimum 2-year (range, 2.1–13.3 years) follow-up. Mean patient age was 67 years (range, 44–86) and 87% were female. All patients had a chronic pelvic discontinuity with the following bone loss patterns: 7 (22%) type IIC, 5 (15%) type IIIA and 20 (63%) type IIIB. At time of final follow-up, radiographs demonstrated 22 of 32 patients (69%) had evidence of a healed discontinuity. Chronic Pelvic Discontinuity Classification. The classification mirrors the Paprosky classification and requires a more complex reconstruction with each progressive type. For the 20 patients with a type IIIB acetabular bone loss pattern, the new classification was applied. The distribution of classification types was as follows: type I 6 (30%); type II 5 (25%); type IIIA 4 (20%); type IIIB 5 (25%); and type IV 0. Overall, 70% (14) patients required the use of an augment for acetabular reconstruction. Conclusions. Acetabular distraction has been established as an effective method by which to treat chronic pelvic discontinuity. The new classification helps to determine the complexity of reconstruction required for each discontinuity, especially when assessing the most severe acetabular defects (Paprosky IIIB). The authors advocate acetabular distraction with a jumbo cup and modular porous metal augments as the preferred treatment for acetabular bone loss with associated chronic pelvic discontinuity. According to the new classification, the likelihood of utilizing augment(s) increases with severity of bone loss. Future studies are required to validate this new chronic pelvic discontinuity classification

Uncemented hemispherical sockets are the implant of choice for most acetabular revisions. Several studies at mid-term document good clinical results, and furthermore, the implants are both versatile and technically straightforward to insert. When bone loss is present, the indications for uncemented sockets are expanded by using jumbo uncemented cups or uncemented cups placed at a high hip center. The main limitation of uncemented hemispherical cups is the need to place them on sufficient host bone to provide initial mechanical stability with a high, long-term likelihood of biologic fixation. The amount of host bone needed to meet these criteria has been debated. One rule of thumb that has been used is 50% surface area contact of the shell with host bone. However, for large sockets with a large surface area, a smaller percentage of the surface in contact with host bone may prove acceptable, provided the shell has host bone support in key areas including a peripheral rim fit and support in the dome of the socket. When these criteria cannot be fulfilled, an alternative method of acetabular reconstruction must be considered. These alternatives include structural bone grafts, impaction grafting, and anti-protrusio cages. Anti-protrusio cages have the advantage of distributing forces over a large surface area of native bone, resisting migration, and being compatible with either bulk or particulate graft in massive acetabular deficiencies. These implants do not provide for biologic fixation and thus their use probably is best restricted to situations in which porous coated implants are not likely to work. Pelvic discontinuity is a specific form of acetabular bone deficiency in which there is a transverse fracture of the acetabulum. Usually this occurs in association with marked acetabular bone loss and represents a stress fracture through deficient bone. Preoperative findings suggestive of pelvic discontinuity include: medial/lateral offset of the superior pelvis relative to the inferior hemipelvis, malrotation of the inferior hemipelvis relative to superior hemipelvis, or visible fracture line demonstrating the pelvic discontinuity. Judet films and true lateral radiographs of the hip can be helpful to delineate the presence of pelvic discontinuity. The treatment principles for pelvic discontinuity include the following: 1.) gain stable fixation of the new acetabular implant. When the bone deficiency is relatively modest this may be possible with a hemispherical uncemented socket. Frequently, however, bone deficiency is massive and an anti-protrusio cage is necessary; 2.) restore pelvic continuity and stability. Usually this is possible with just a posterior column plate; 3.) bone graft large defects using particulate versus structural bone graft. In massive deficiencies structural bone grafts have the advantage of bridging the discontinuity and allowing healing of the native pelvis to the structural graft inferiorly and superiorly which may promote healing of the discontinuity. The results of treatment of pelvic discontinuity are dependent on the severity of bone loss and whether or not the pelvis had previous therapeutic radiation; milder bone loss is associated with better results; and more severe bone loss and previous therapeutic pelvic radiation with worse results. Surgery for pelvic discontinuity is complex and the most common complications include recurrent instability, infection, and sciatic neuropathy

In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity. Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultraporous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultraporous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven cup cage procedures with an average follow-up of 74 months (range, 24–135 months; SD, 34.3 months) were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Failure was defined as revision surgery for any cause, including infection. The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval, 83.1–97.4), and the 10-year survival rate was 85% (95% CI, 67.2–93.8). The Merle d'Aubigné-Postel score improved significantly from a mean of 6 pre-operatively to 13 post-operatively (p < 0.001). Four cup-cage constructs had non-progressive radiological migration of the ischial flange and they remain stable

Pelvic discontinuity with associated bone loss is a complex challenge acetabular revision surgery. Reconstruction by the use of ilio-ischial cages combined with trabecular metal acetabular components and morsellised bone (the component-cage technique) is a relatively new method of treatment. The trabecular cup provides a good environment for bone graft remodeling and eventual bone or fibrous ingrowth. The cage protects the trabecular metal cup until stabilisation occurs. The cage not only protects the cup but places the articulating center at the correct level. We reviewed a consecutive series of 32 cases of acetabular revision reconstructions with pelvic discontinuity who had been treated by the cup-cage technique. The mean follow-up was 38 months (24.0 to 68.0). Failure was defined as a migration of a component of >5mm. In 29 hips there was no clinical or radiological evidence of loosening at the last follow-up. The Harris hip scores improved significantly from 44.6 (sd 10.4) to 78.7 (sd 10.4) points (p<0.001). In three hips (11.5%) the construct migrated at one year after surgery. The complications included two cases of dislocations, one of infection and one of partial palsy of the peroneal nerve. Our findings indicated that the treatment of pelvic discontinuity by the component-cage construct is a reliable option

Pelvic discontinuity remains one of the most difficult reconstructive challenges during acetabular revision. Bony defects are extremely variable and remaining bone quality may be extremely poor. Careful pre-operative imaging with plain radiographs, oblique views, and CT scanning is recommended to improve understanding of the remaining bone stock. It is wise to have several options available intra-operatively including metal augments, jumbo cups, and cages. Various treatment options have been used with variable success. The principles of management include restoration of acetabular stability by “connecting” the ilium to the ischium, and by (hopefully) allowing some bony ingrowth into a porous surface to allow longer-term construct stability. Posterior column plates can be useful to stabilise the pelvis, and can supplement a trabecular metal uncemented acetabular component. Screws into the dome and into the ischium are used to span the discontinuity. More severe defects may require so-called “cup-cage” constructs or trabecular metal augmentation distraction techniques. The most severe defects typically necessitate custom triflange components. Triflange constructs allow broad based contact with remaining bone stock, and can span surprisingly large defects. Recent cost analyses have shown that custom triflange constructs are comparable to cup-cage-augment reconstructions. The results of these various solutions to manage pelvic discontinuity is extremely variable, however, it is fair to conclude that constructs that allow some bony ingrowth have demonstrated improved survivorship when compared to historical treatments such as bulk allografts protected by cages. The author prefers a posterior column plate and a trabecular metal cup for simple discontinuities, a cup-cage for larger defects, and a custom triflange for the most severe defects. Pre-operative imaging is critical to guide this decision-making, and careful attention to detail is important to obtain a stable, durable construct

The advent of trabecular metal (TM) augments has revolutionized the management of severe bone defects during acetabular reconstruction. The purpose of this study was to evaluate patients undergoing revision total hip arthroplasty (THA) with the use of TM augments for reconstruction of Paprosky 3A, 3B defects and defects associated with pelvic discontinuity. A retrospective study was conducted of the cases performed at four centers between August 2007 and January 2015. Patients treated with TM augments for Paprosky 3A, 3B or chronic pelvic discontinuity were included in the study. All surgeries were performed through a posterior approach. A total of 57 patients (Male 34 (69%), Female 23(31%)), mean age 54 years (range, 28–94 years), with minimum follow up of one-year were included and evaluated using intention to treat analysis. There were 44 (77%) patients with a 3A defect, 11(19%) patients with a 3B defect (6 had an associated pelvic discontinuity), and 2 (3.5%) with a 2C defect and associated pelvic discontinuity. The mean follow-up was 37 months (range, 12–96 months). One (2%) patient died after 8 years of unrelated causes. Three (5.5%) patients had acetabular component loosening requiring revision; Two failures were (3.5%) due to aseptic loosening and one (2%) due to septic loosening. Fifty-four patients had a radiologically stable integration of the components at latest follow-up - survivorship was 94.7%. The results of this multi-center study demonstrate encouraging short and mid-term results for the use of TM augments in the management of Grade 3A and 3B defects, and defects associated with a chronic pelvic discontinuity

The treatment of severe acetabular bone loss is challenging, especially in the setting of an associated chronic pelvic discontinuity. There are several available treatment options for chronic pelvic discontinuity, each of which has its own disadvantages. One of the major difficulties with this entity, regardless of the reconstructive technique chosen, is the inability to obtain reproducible healing of the discontinuity. We evaluated the use of acetabular distraction, a technique which achieves peripheral or lateral distraction and central or medial compression across the discontinuity. We recommend acetabular distraction to allow for implantation of a stable construct, achieve biologic fixation and increase the likelihood of discontinuity healing. In this multi-center trial, 32 patients that underwent acetabular revision for a chronic pelvic discontinuity using acetabular distraction were radiographically evaluated at a minimum of 25 months (range, 25 to 160 months). The study cohort was categorized according to the Paprosky acetabular bone loss classification: seven (22%) type IIC, five (16%) type IIIA, and 20 (62%) type IIIB defects. Fourteen (70%) of the 20 patients with a type IIIB acetabular bone loss pattern required use of augments for acetabular reconstruction. Of the 32 patients, 1 (3%) patient required a revision for aseptic loosening, 2 (6%) patients had evidence of radiographic loosening but were not revised, and 3 (9%) patients had migration of the acetabular component into a more stable position. Radiographically, 22 (69%) of the cohort demonstrated healing of the discontinuity. The Kaplan-Meier construct survivorship was 83.3% when using aseptic acetabular loosening as an end-point. During this study, the authors created a new pelvic discontinuity classification based on the type of reconstruction required. The classification mirrors the Paprosky acetabular bone loss classification. A Type I chronic pelvic discontinuity required jumbo cup reconstruction without augments. A type II discontinuity required the use of an augment for an extracavitary defect. A type III discontinuity required an augment for an intracavitary defect. Type III defects were further subdivided into type IIIA and IIIB discontinuity. Type IIIA discontinuities utilized an augment to reconstruct the anterosuperior and/or posteroinferior column defect for primary stability of the overall construct. Type IIIB discontinuities utilized augments to reconstruct the anterosuperior and/or posteroinferior column defect for primary stability as well as a posterosuperior augment for supplemental fixation. All augments were unitized to the cup with cement. Type IV defects were massive defects that required the use of two orange-slice augments, secured together with screws and placed centrally to restore the defect, and a cup implanted and unitized to the augments with cement. According to this new classification, the discontinuity reconstructions in our study were classified as follows: 12 (38%) type I, 8 (25%) type II, 6 (19%) type IIIA, 6 (19%) type IIIB, and 0 as type IV. Acetabular distraction technique demonstrates favorable radiographic outcomes with reproducible discontinuity healing in a majority of cases. This alternative technique allows for biologic fixation and intra-operative customization of the construct to be implanted based on the bone loss pattern present following component removal

Although the introduction of ultraporous metals in the forms of acetabular components and augments has substantially improved the orthopaedic surgeon's ability to reconstruct severely compromised acetabuli, there remain some revision THAs that are beyond the scope of cups, augments, and cages. In situations involving catastrophic bone loss, allograft-prosthetic composites or custom acetabular components may be considered. Custom components offer the potential advantages of immediate, rigid fixation with a superior fit individualised to each patient. These custom triflange components require a pre-operative CT scan with 3-D reconstruction using rapid prototyping technology. The surgeon can fine-tune exact component positioning, determine location and length of screws, modify the fixation surface with, for example, the addition of hydroxyapatite, and dictate which screws will be locked to enhance fixation. The general indications for using custom triflange components include: (1) failed prior salvage reconstruction with cage or porous metal construct augments, (2) large contained defects with possible discontinuity, (3) known pelvic discontinuity, and (4) complex multiply surgically treated hips with insufficient bone stock to reconstruct using other means. The general indications for using custom triflange components include: (1) failed prior salvage reconstruction with cage or porous metal construct augments, (2) large contained defects with possible discontinuity, (3) known pelvic discontinuity, and (4) complex multiply surgically treated hips with insufficient bone stock to reconstruct using other means. We previously reported on our center's experience with 23 patients (24 hips) treated with custom triflange components with minimum 2-year follow-up. This method of reconstruction was used in a cohort of patients with Paprosky Type 3B acetabular defects, which represented 3% (30 of 955) of the acetabular revisions we performed during the study period of 2003 to 2012. At a mean follow-up of 4.8 years (range, 2.3–9 years) there were 4 subsequent surgical interventions: 2 failures secondary to sepsis, and 1 stem revision and 1 open reduction internal fixation for periprosthetic femoral fracture. There were two minor complications managed non-operatively, but all of the components were noted to be well-fixed with no obvious migration or loosening observed on the most recent radiographs. Harris Hip Scores improved from a mean of 42 (SD ±16) before surgery to 65 (SD ±18) at latest follow-up (p<0.001). More recently, we participated in a multi-center study of 95 patients treated with reconstruction using custom triflange components w a mean follow-up of 3.5 years. Pelvic defects included Paprosky Type 2C, 3A, 3B and pelvic discontinuity. Concomitant femoral revision was performed in 21 hips. Implants used a mean of 12 screws with 3 locking screws. Twenty of 95 patients (21%) experienced at least one complication, including 6% dislocation, 6% infection, and 2% femoral-related issues. Implants were ultimately removed in 11% of hips. One hip was revised for possible component loosening. Survivorship with aseptic loosening as the endpoint was 99%. Custom acetabular triflange components represent yet another tool in the reconstructive surgeon's armamentarium. These devices can be helpful in situations of catastrophic bone loss, achieving reliable fixation. Clinical results are inferior to both primary THA and more routine revision THA. Patients and surgeons should be aware of the increased complications associated with these complex hip revisions

Pelvic discontinuity with associated bone loss is a complex challenge in acetabular revision surgery. Reconstruction using ilio-ischial cages combined with trabecular metal acetabular components and morsellised bone (the component-cage technique) is a relatively new method of treatment. We reviewed a consecutive series of 26 cases of acetabular revision reconstructions in 24 patients with pelvic discontinuity who had been treated by the component-cage technique. The mean follow-up was 44.6 months (24 to 68). Failure was defined as migration of a component of > 5 mm. In 23 hips (88.5%) there was no clinical or radiological evidence of loosening at the last follow-up. The mean Harris hip score improved significantly from 46.6 points (29.5 to 68.5) to 76.6 points (55.5 to 92.0) at two years (p < 0.001). In three hips (11.5%) the construct had migrated at one year after operation. The complications included two dislocations, one infection and one partial palsy of the peroneal nerve. Our findings indicate that treatment of pelvic discontinuity using the component-cage construct is a reliable option

Aims. The aim of this study was to examine the results of the acetabular distraction technique in achieving implantation of a stable construct, obtaining biological fixation, and producing healing of chronic pelvic discontinuity at revision total hip arthroplasty. Patients and Methods. We identified 32 patients treated between 2006 and 2013 who underwent acetabular revision for a chronic pelvic discontinuity using acetabular distraction, and who were radiographically evaluated at a mean of 62 months (25 to 160). Of these patients, 28 (87.5%) were female. The mean age at the time of revision was 67 years (44 to 86). The patients represented a continuous series drawn from two institutions that adhered to an identical operative technique. Results. Of the 32 patients, one patient required a revision for aseptic loosening, two patients had evidence of radiographic loosening but were not revised, and three patients had migration of the acetabular component into a more stable configuration. Radiographically, 22 (69%) of the cohort demonstrated healing of the discontinuity. The Kaplan–Meier construct survivorship was 83.3% when using revision for aseptic acetabular loosening as an endpoint. At the time when one patient failed due to aseptic loosening (at 7.4 years), there were a total of seven patients with a follow-up of seven years or longer who were at risk of failure. Conclusion. The acetabular distraction technique demonstrates encouraging radiographic outcomes, with healing of the discontinuity in over two-thirds of our series. This surgical technique permits biological fixation and intraoperative customization of the construct to be implanted based on the pattern of the bone loss identified following component removal. Cite this article: Bone Joint J 2018;100-B:909–14

Revision surgery for pelvic discontinuity in the presence of bone loss is challenging. The cup-cage reconstruction option has become popular for the management of pelvic discontinuity in the recent years. The aim of this study was to review the clinical, radiological and patient reported outcomes with the use of cup cage construct for pelvic discontinuity at our institution. Twenty-seven patients (27 cup-cage reconstructions) were identified at median 6-year (minimum 2 year, maximum 10 years) follow up. Eight were female patients. The median age was 77 years [mean 72, range 37–90, SD 13.6]. There were 5 deaths and 2 were lost to follow up. Two patients were converted to excision arthroplasty; one for infection and one for failure of the construct. A further 3 patients required revision for instability but the cup cage construct was not revised (2 revisions of cemented cups to a constrained cup and one revision of proximal modular component of the femoral prosthesis). Revision of the cup cage construct was not necessary in any of these cases. We noted excellent pain relief (mean WOMAC pain 85.6) and good functional outcome (mean WOMAC function 78.2, mean UCLA 5, mean OHS 78.6). Patient satisfaction with regards pain relief; function and return to activities were noted to be excellent. Radiological changes were noted in further 4 patients (cup migration in one case; fracture of ischial spike in one case and breakage of the cage screws in 2 patients). No migration of the construct was noted in any of the cases. In conclusion, the cup cage construct is an excellent method of dealing with complex pelvic discontinuity. Our study suggests a low failure rate; high patient satisfaction and pain relief and moderate functional outcome at median 6 year follow up

Acetabular distraction for the treatment of chronic pelvic discontinuity was first described by Sporer and Paprosky. The authors advocate the posterolateral approach for exposure of the posterior ilium and posterior column, The patient is secured in the lateral decubitus position. Following a systematic approach to surgical exposure, acetabular component removal should be performed with “cup out” osteotomes resulting in minimal iatrogenic bone loss. Following component removal and confirmation of a chronic discontinuity determine the integrity of the remaining AS and PI columns. If porous metal augments are needed for primary stabilization, the augments are placed prior to cup insertion for reconstruction of the AS and/or PI column. Next, Kirschner (K) wires (size 2.4) are placed in the remaining AS and PI bone so that the distractor can be secured in an extra-acetabular position. The distractor is placed over the K-wires allowing for lateral or peripheral acetabular distraction and resultant medial or central compression at the discontinuity. With the distractor in an extra-acetabular position, hemispherical reamers are used until an interference fit is achieved between the native or augmented AS and PI columns. The acetabulum should be reamed on reverse to avoid excessive removal of host bone. When the proper acetabular component size has been reached, the reamer will disengage from the reamer handle and the reamer can be used as a surrogate acetabular shell; when the acetabulum is maximally distracted, the entire construct will move as a unit. Crushed cancellous allograft is used to bone graft the discontinuity and reamed on reverse. A revision tantalum cup is inserted with continual distraction using the distractor. Cement is applied to the augment surface prior to cup insertion in order to utilise the construct. Following cup insertion, the distractor and K-wires are removed. Adjuvant screw fixation is performed, with a minimum of 4 screws, and placing at least one of the screws inferiorly for fixation in the superior public ramus or ischium to prevent abduction failure of the construct. In the setting of severely osteoporotic bone and inadequate screw fixation, an augment placed posterosuperiorly can be used for supplemental fixation. This augment is also unitised to the cup with cement at the same time as the liner is cemented into the cup. Bone wax is placed over the exposed tantalum surface of the posterosuperior augment to minimise soft-tissue ingrowth into the augment

Pelvic discontinuity (PD) is a detrimental complication following total hip arthroplasty (THA). The aim of this study was to assess the clinical and radiological results of patients with PD who were revised using a custom-made triflange acetabular component (CTAC). This is a single centre prospective study of patients with PD following THA who were treated with a CTAC. The Hip Disability and Osteoarthritis Outcome Score (HOOS), modified Oxford Hip Score (mOHS), EurQol five-dimension three-level (EQ-5D-3L) utility, and Numeric Rating Scale (NRS), including visual analogue score (VAS) for pain, were gathered at baseline, and at one- and two-year follow-up. Clinical and radiological complications, including reasons for revisions were registered. Trends over time are described and tested for significance and clinical relevance. 18 females with 22 CTACs were included with a mean age of 73.5 years (SD 7.7). There were significant improvements between baseline and final follow-up in HOOS (p<0.01), mOHS (p<0.01), EQ-5D-3L utility (p<0.01), EQ-5D-3L NRS (p<0.01), VAS pain rest (p<0.01), and VAS pain activity (p<0.01). A minimal clinically important improvement in mOHS and the HOOS was observed in 16 patients (73%) and 14 patients (64%), respectively. Definite healing of the PD was observed in 19 hips (86%). Complications included six cases with broken screws (27%), four cases (18%) with bony fractures, and one case (4.5%) with sciatic nerve paresthesia. One patient with concurrent bilateral PD had revision surgery due to recurrent dislocations. No revision surgery was performed for screw failure or implant breakage. This is the first prospective assessment in clinical outcome of patients with PD who were treated with a CTAC. We have demonstrated that CTAC in patients with THA acetabular loosening and PD can result in stable constructs with no mechanical failures. Moreover, clinically relevant improvements in health-related quality of life at two years’ follow-up was observed

Purpose: Pelvic discontinuity associated with bone loss is a complex challenge in acetabular revision surgery. Reconstruction with anti protrusion cages, Trabecular Metal (Zimmer, Warsaw, Indiana) cups and morselized bone (Cup-Cage) constructs is a relatively new technique used by the authors for the past 6 years. The purpose of the study was to examine the clinical outcome of these patients. Method: Thirty-two consecutive acetabular revision reconstructions in 30 patients with pelvic discontinuity and bone loss treated by cup cage technique between January 2003 and September 2007 were reviewed. Average clinical and radiological follow up was 38.5 ± 19 months (range 12 – 68, median 34.5). Failure was defined as component migration > 5mm. Results: In 29 (90.6%) patients there was no clinical or radiographic evidence indicative of loosening at latest follow up. Harris Hip Scores improved significantly (p< 0.001) from 46.6 ± 10.4 to 78.7 ± 10.4 at 2 year follow up. In 3 patients the construct migrated at 1 year post surgery. One construct was revised to anti protrusion cage with a structural graft while the other was revised to a large Trabecular Metal cup. The third patient is scheduled for revision. Complications included 2 dislocations, 1 infection and 1 partial peroneal nerve palsy. Two patients died due to unrelated reasons at 1 and 3 years post surgery, respectively. Conclusion: Treatment of pelvic discontinuity by Cup-Cage construct is a reliable option based on preliminary results which suggest restoration of the pelvic mechanical stability. However, patients should be followed closely in order to detect cup migration until satisfactory bony ingrowth into the cup takes place

Trabecular metal (TM) augments are a relatively new option for reconstructing segmental bone loss during acetabular revision. We studied 34 failed hip replacements in 34 patients that were revised between October 2003 and March 2010 using a TM acetabular shell and one or two augments. The mean age of the patients at the time of surgery was 69.3 years (46 to 86) and the mean follow-up was 64.5 months (27 to 107). In all, 18 patients had a minor column defect, 14 had a major column defect, and two were associated with pelvic discontinuity. The hip centre of rotation was restored in 27 patients (79.4%). The Oxford hip score increased from a mean of 15.4 points (6 to 25) before revision to a mean of 37.7 (29 to 47) at the final follow-up. There were three aseptic loosenings of the construct, two of them in the patients with pelvic discontinuity. One septic loosening also occurred in a patient who had previously had an infected hip replacement. The augments remained stable in two of the failed hips. Whenever there was a loose acetabular component in contact with a stable augment, progressive metal debris shedding was evident on the serial radiographs. Complications included another deep infection treated without revision surgery. Good clinical and radiological results can be expected for bone-deficient acetabula treated by a TM cup and augment, but for pelvic discontinuities this might not be a reliable option. Cite this article: Bone Joint J 2013;95-B:166–72

Aim. Until now, there has been no consensus as to whether stemmed acetabular components are appropriate for use in patients undergoing revision total hip arthroplasty (THA) who have major acetabular defects or pelvic discontinuity. We wished to address this deficiency in the literature. Patients and Methods. We carried out a retrospective study of 35 patients (six men and 29 women) with a mean age of 68 years (37 to 87), with major acetabular defects who underwent revision THA between 2000 and 2012. Results. At a mean follow-up of 63 months (24 to 141), a total of 15 patients (43%) had required at least one further operation. Six implants (17%) loosened aseptically, four (11%) were further revised for infection and two (6%) for technical failure. By taking revision for any reason as the endpoint, the rate of survival of the implant was 61% after five years; by taking revision for aseptic loosening as the end point, it was 78%. The cumulative five-year survival for aseptic loosening was 94% in patients without pelvic discontinuity, and 56% in those with pelvic discontinuity. Conclusion. These results indicate a significantly worse survival in patients with pelvic discontinuity (p = 0.020) and we advise caution in the use of the pedestal component in patients with major acetabular defects and pelvic discontinuity who require revision THA. As a result of these findings we have stopped using this implant and prefer to use particulate bone grafts protected with an anti-protrusion cage and posterior column plate fixation, if necessary. Take home message: Based on these poor results, we advise caution if using the pedestal component in patients with major acetabular defects with the presence of a pelvic discontinuity. . Cite this article: Bone Joint J 2016;98-B:772–9

The advent of modular porous metal augments has ushered in a new form of treatment for acetabular bone loss. The function of an augment can be seen as reducing the size of a defect or reconstituting the anterosuperior/posteroinferior columns and/or allowing supplementary fixation. Depending on the function of the augment, the surgeon can decide on the sequence of introduction of the hemispherical shell, before or after the augment. Augments should always, however, be used with cement to form a unit with the acetabular component. Given their versatility, augments also allow the use of a hemispherical shell in a position that restores the centre of rotation and biomechanics of the hip. Progressive shedding or the appearance of metal debris is a particular finding with augments and, with other radiological signs of failure, should be recognized on serial radiographs. Mid- to long-term outcomes in studies reporting the use of augments with hemispherical shells in revision total hip arthroplasty have shown rates of survival of > 90%. However, a higher risk of failure has been reported when augments have been used for patients with chronic pelvic discontinuity. Cite this article: Bone Joint J 2024;106-B(4):312–318

Aims. The use of trabecular metal (TM) shells supported by augments has provided good mid-term results after revision total hip arthroplasty (THA) in patients with a bony defect of the acetabulum. The aim of this study was to assess the long-term implant survivorship and radiological and clinical outcomes after acetabular revision using this technique. Patients and Methods. Between 2006 and 2010, 60 patients (62 hips) underwent acetabular revision using a combination of a TM shell and augment. A total of 51 patients (53 hips) had complete follow-up at a minimum of seven years and were included in the study. Of these patients, 15 were men (29.4%) and 36 were women (70.6%). Their mean age at the time of revision THA was 64.6 years (28 to 85). Three patients (5.2%) had a Paprosky IIA defect, 13 (24.5%) had a type IIB defect, six (11.3%) had a type IIC defect, 22 (41.5%) had a type IIIA defect, and nine (17%) had a type IIIB defect. Five patients (9.4%) also had pelvic discontinuity. Results. The overall survival of the acetabular component at a mean of ten years postoperatively was 92.5%. Three hips (5.6%) required further revision due to aseptic loosening, and one (1.9%) required revision for infection. Three hips with aseptic loosening failed, due to insufficient screw fixation of the shell in two and pelvic discontinuity in one. The mean Harris Hip Score improved significantly from 55 (35 to 68) preoperatively to 81 points (68 to 99) at the latest follow-up (p < 0.001). Conclusion. The reconstruction of acetabular defects with TM shells and augments showed excellent long-term results. Supplementary screw fixation of the shell should be performed in every patient. Alternative techniques should be considered to address pelvic disconinuity. Cite this article: Bone Joint J 2019;101-B:311–316

Aims. The aims of this study were to determine the success of a reconstruction algorithm used in major acetabular bone loss, and to further define the indications for custom-made implants in major acetabular bone loss. Methods. We reviewed a consecutive series of Paprosky type III acetabular defects treated according to a reconstruction algorithm. IIIA defects were planned to use a superior augment and hemispherical acetabular component. IIIB defects were planned to receive either a hemispherical acetabular component plus augments, a cup-cage reconstruction, or a custom-made implant. We used national digital health records and registry reports to identify any reoperation or re-revision procedure and Oxford Hip Score (OHS) for patient-reported outcomes. Implant survival was determined via Kaplan-Meier analysis. Results. A total of 105 procedures were carried out in 100 patients (five bilateral) with a mean age of 73 years (42 to 94). In the IIIA defects treated, 72.0% (36 of 50) required a porous metal augment; the remaining 14 patients were treated with a hemispherical acetabular component alone. In the IIIB defects, 63.6% (35 of 55) underwent reconstruction as planned with 20 patients who actually required a hemispherical acetabular component alone. At mean follow-up of 7.6 years, survival was 94.3% (95% confidence interval 97.4 to 88.1) for all-cause revision and the overall dislocation rate was 3.8% (4 of 105). There was no difference observed in survival between type IIIA and type IIIB defects and whether a hemispherical implant alone was used for the reconstruction or not. The mean gain in OHS was 16 points. Custom-made implants were only used in six cases, in patients with either a mega-defect in which the anteroposterior diameter > 80 mm, complex pelvic discontinuity, and massive bone loss in a small pelvis. Conclusion. Our findings suggest that a reconstruction algorithm can provide a successful approach to reconstruction in major acetabular bone loss. The use of custom implants has been defined in this series and accounts for < 5% of cases. Cite this article: Bone Joint J 2024;106-B(5 Supple B):47–53

Despite considerable legacy issues, Girdlestone's Resection Arthroplasty (GRA) remains a valuable tool in the armoury of the arthroplasty surgeon. When reserved for massive lysis in the context of extensive medical comorbidities which preclude staged or significant surgical interventions, and / or the presence of pelvic discontinuity, GRA as a salvage procedure can have satisfactory outcomes. These outcomes include infection control, pain control and post-op function. We describe a case series of 13 cases of GRA and comment of the indications, peri, and post-operative outcomes. We reviewed all cases of GRA performed in our unit during an 8 year period, reviewing the demographics, indications, and information pertaining to previous surgeries, and post op outcome for each. Satisfaction was based on a binary summation (happy/unhappy) of the patients’ sentiments at the post-operative outpatient consultations. 13 cases were reviewed. They had a mean age of 75. The most common indication was PJI, with 10 cases having this indication. The other three cases were performed for avascular necrosis, pelvic osteonecrosis secondary to radiation therapy and end stage arthritis on a background of profound learning disability in a non-ambulatory patient. The average number of previous operations was 5 (1-10). All 13 patients were still alive post girdlestone. 7 (54%) were satisfied, 6 were not. 3 patients were diabetic. 5 patients developed a sinus tract following surgery. With sufficient pre-op patient education, early intensive physiotherapy, and timely orthotic input, we feel this procedure remains an important and underrated and even compassionate option in the context of massive lysis and / or the presence of pelvic discontinuity / refractory PJI. GRA should be considered not a marker of failure but as a definitive procedure that gives predictability to patients and surgeon in challenging situations

Cup-cage constructs are one of several methods commonly used to treat severe acetabular bone loss during contemporary revision total hip arthroplasty. The purpose of this study was to provide a long-term results of the technique with emphasis on implant survivorship, radiographic results, and clinical outcomes for both full and half cup-cage reconstructions. We identified 57 patients treated with a cup-cage reconstruction for major acetabular bone loss between 2002–2012. All patients had Paprosky Type 2B through 3B bone loss, with 60% having an associated pelvic discontinuity. Thirty-one patients received a full cup-cage construct, and 26 a half cup-cage. Mean age at reconstruction was 66 years, 75% were female, and the mean BMI was 27 kg/m. 2. Mean follow-up was 10 years. The 10-year cumulative incidences of any revision were 14% and 12% for the full and half cup-cage construct groups, respectively. Of the 9 revisions, 3 were for dislocation, 2 for aseptic loosening and construct failure (both were pelvic discontinuities), 1 for adverse local tissue reaction, and 1 for infection with persistent pelvic discontinuity. The 10-year cumulative incidences of revision for aseptic loosening were 4.5% and 5% for the full and half cup-cage constructs, respectively. Of the unrevised cases, incomplete and non-progressive zone 3 radiolucent lines were observed in 10% of patients in each group. Three patients experienced partial motor and sensory sciatic nerve palsies (2 in the full and 1 in the half cup-cage group). Both the full and half cup-cage cohorts demonstrated significantly improved Harris hip scores. Full and half cup-cage reconstructions for major acetabular defects were successful at 10 years in regards to acetabular fixation without appreciable differences between the two techniques. However, zone 3 radiolucent lines were not uncommon in association with discontinuities, and dislocation continues to be a problem

Introduction. Pelvic discontinuity is a challenging complication. One treatment option that has garnered enthusiasm is acetabular distraction. This method obtains stability via distraction of the discontinuity and placement of an oversized socket (± augments) and elastic recoil of the pelvis. The aims of this study were to report implant survivorship, radiographic results, clinical outcomes, and complications of acetabular distraction for pelvic discontinuity in the largest series to date. Methods. We retrospectively identified all revision THAs with a Paprosky 3B defect and pelvic discontinuity between 2005 and 2017. Of the 162 patients, 32 were treated with distraction. The mean distraction achieved was 5mm (range, 3–8mm). In addition to distraction with a hemispherical cup, augments were utilized in 3 and cages in 19. The mean age at revision was 68 years with 75% female. Mean follow-up was 3 years. Results. The 2-year survivorships free from revision for aseptic loosening, revision, and reoperation were 95%, 75%, and 69%, respectively. There were 3 revisions including one for instability, one for infection, and one for aseptic loosening. At last follow-up, 16 patients had radiographic evidence of cup osteointegration to ilium and ischium, 13 to ilium only, and 3 without evidence of osteointegration (two distracted 3mm and one distracted 6mm). 19 discontinuity lines persisted while 13 had radiographically healed. Only those with osteointegration to both ilium and ischium had evidence of bone graft consolidation and discontinuity line healing. Mean HHS improved from 43 preoperatively to 77 postoperatively (p<0.0001). The most common complication was a postoperative sciatic nerve plasy in 4 patients (13%) of which 3 partially recovered. Conclusion. Pelvic discontinuities treated with acetabular distraction had a 2-year survivorship free from aseptic looseing of 95%. While nearly 2/3. rd. of discontinuity lines persisted, 91% of patients had radiographic evidence of osteointegration of the acetabular component. However, 13% of patients had a sciatic nerve palsy. For any tables or figures, please contact the authors directly

Acetabular bone loss is a challenging problem facing the revision total hip replacement surgeon. Reconstruction of the acetabulum depends on the presence of anterosuperior and posteroinferior pelvic column support for component fixation and stability. The Paprosky classification is most commonly used when determining the location and degree of acetabular bone loss. Augments serve the function of either providing primary construct stability or supplementary fixation. . When a pelvic discontinuity is encountered we advocate the use of an acetabular distraction technique with a jumbo cup and modular porous metal acetabular augments for the treatment of severe acetabular bone loss and associated chronic pelvic discontinuity. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):36–42

A pelvic discontinuity occurs when the superior and inferior parts of the hemi-pelvis are no longer connected, which is difficult to manage when associated with a failed total hip replacement. Chronic pelvic discontinuity is found in 0.9% to 2.1% of hip revision cases with risk factors including severe pelvic bone loss, female gender, prior pelvic radiation and rheumatoid arthritis. Common treatment options include: pelvic plating with allograft, cage reconstruction, custom triflange implants, and porous tantalum implants with modular augments. The optimal technique is dependent upon the degree of the discontinuity, the amount of available bone stock and the likelihood of achieving stable healing between the two segments. A method of treating pelvic discontinuity using porous tantalum components with a distraction technique that achieves both initial stability and subsequent long-term biological fixation is described. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):73–7

The custom triflange acetabular component has been advocated for severe acetabular defects and pelvic discontinuity, cases in which a porous-coated hemisphere will not work. These are AAOS type III or IV defects, or alternatively classified as Paprosky 3B. Many have a pelvic discontinuity. A preoperative CT of the pelvis is sent to the manufacturer who generates a one to one scale 3D model of the hemipelvis. If the visualised defect cannot be treated with traditional methods then a triflanged component is created. Initial rigid fixation is obtained with screw fixation to the ilium and ischium. Subsequent bone ingrowth can provide long term fixation. The goal is to span the acetabular defect and obtain fixation to ilium and ischium with a third flange which rests on the pubis. Christie first reported on 67 hips (half with a discontinuity) with a mean follow-up of 53 months. No components were removed. There was an 8% reoperation for dislocation, 6% partial sciatic nerve palsy. Dennis reported 26 hips with a mean 54 month follow-up. Eighty-eight percent were considered successful. Taunton reported 57 cases with a pelvic discontinuity treated with a triflange at mean follow-up of 65 months. Eighty-one percent had a stable component and a healed pelvic discontinuity. The primary disadvantage of the technique is the preoperative time required to manufacture the device – typically 4–8 weeks

Acetabular components used to treat large defects are at greater risk of loosening. Porous tantalum acetabular components have reported the most promising early to midterm revision rates. Early stability of acetabular components used at revision THR was shown to be a good predictor of later loosening. The primary aim was to assess the migration of porous acetabular component used to reconstruct severe acetabular defects. Secondarily, we investigated the effect of acetabular defect severity and type of component fixation on migration. Radiosterometric analysis was used to measure migration at a mean follow-up of four years, (range 2–10) in 59 reconstructions of severe acetabular defects with porous tantalum components. Acetabular component fixation was classified as superior if augmented with screws through cup, augments or cage in the ilium only. Fixation was classified as combined, superior and inferior, if flanges and/or screws were also placed in the ischium and or pubis. Acceptable limits of proximal migration were defined as ≤1mm within 2 years and ≤2.5mm at any time point. Eight hips had reconstruction of Paprosky II defects with superior fixation only. The mean proximal migration of the eight acetabular components was 0.25mm (0.08–0.40) at 2 years and 0.29mm (0.10–0.81) at last follow-up. Fifty-one hips had reconstruction of Paprosky III defects. Seven of these reconstructions exceeded the migration thresholds. Five reconstructions (four with superior fixation and one cup cage construct with no inferior screw fixation) of hips with pelvic discontinuity developed pain and were re-revised for loosening. Two reconstructions are asymptomatic and migrated 2.68mm (cup-cage construct with superior screws) and 2.86mm (no pelvic discontinuity, superior fixation) at final follow-up. The mean proximal migration of the 51 Paprosky III reconstructions was 0.99mm (0.03 to 16.4) at 2 years and 1.92mm (0.01 to 29.4) at last follow-up. The mean proximal translation at 2 years of the 11 reconstructions with inferior screw fixation was 0.2mm (−0.6 to 0.7mm), compared with 0.9mm (−0.6 to 16.4mm) for the reconstructions without inferior screw fixation. In conclusion, when used to reconstruct Paprosky II defects, porous tantalum acetabular components provide component stability similar to a good performing primary THR. These implants achieve adequate stability when used to treat Paprosky III defects, including those with pelvic discontinuity. For the most severe defects, combined fixation with inferior screws is recommended, particularly when reconstructing hips with pelvic discontinuity

The custom triflange acetabular component has been advocated for severe acetabular defects and pelvic discontinuity, cases in which a porous-coated hemisphere will not work. These are AAOS type III or IV defects, or alternatively classified as Paprosky 3B. Many have a pelvic discontinuity. A pre-operative CT of the pelvis is sent to the manufacturer who generates a one-to-one scale 3D model of the hemipelvis. The surgeon can review either a pdf file or an actual model. If the visualised defect cannot be treated with traditional methods then a triflanged component is created. The components have backside porous and hydroxyapatite coating. Initial rigid fixation is obtained with screw fixation to the ilium and ischium. Subsequent bone ingrowth can provide long term fixation. The goal is to span the acetabular defect and obtain fixation to the ilium and ischium with a third arm which rests on the pubis. Christie first reported on 67 hips (half with a discontinuity) with a mean follow-up of 53 months. No components were removed. There was an 8% reoperation for dislocation, 6% partial sciatic nerve palsy. 46% walked without support. Dennis reported 26 hips with a mean 54 month follow-up. Eighty-eight percent were considered successful. One implant was removed and left with a resection arthroplasty and 2 others had loose components but refused reoperation. Loosening of the ischial screws was a sign of failure in the three cases. Taunton reported 57 cases with a pelvic discontinuity treated with a triflange at mean follow-up of 65 months. Eighty-one percent had a stable component and a healed pelvic discontinuity. These authors also compared a custom triflange to a trabecular metal cup-cage construct finding similar implant costs of $12,500 and $11,250, respectively. All advocates of custom triflange acetabular components believe the results are similar or superior to other options in these very challenging cases at early follow-up. The primary disadvantage of the technique is the pre-operative time required to manufacture the device – typically 4–8 weeks

The custom triflange acetabular component has been advocated for severe acetabular defects and pelvic discontinuity, cases in which a porous-coated hemisphere will not work. These are AAOS type III or IV defects, or alternatively classified as Paprosky 3B. Many have a pelvic discontinuity. A preoperative CT of the pelvis is sent to the manufacturer who generates a one-to-one scale 3D model of the hemipelvis. The surgeon can review either a pdf file or an actual model. If the visualised defect cannot be treated with traditional methods then a triflanged component is created. The components have backside porous and hydroxyapatite coating. Initial rigid fixation is obtained with screw fixation to the ilium and ischium. Subsequent bone ingrowth can provide long term fixation. The goal is to span the acetabular defect and obtain fixation to ilium and ischium with a third arm which rests on the pubis. Christie first reported on 67 hips (half with a discontinuity) with a mean follow-up of 53 months. No components were removed. There was an 8% reoperation for dislocation, 6% partial sciatic nerve palsy. 46% walked without support. Dennis reported 26 hips with a mean 54 month follow-up. 88% were considered successful. One implant was removed and left with a resection arthroplasty and 2 others had loose components but refused reoperation. Loosening of the ischial screws was a sign of failure in the three cases. Taunton reported 57 cases with a pelvic discontinuity treated with a triflange at mean follow-up of 65 months. 81% has a stable component and a healed pelvic discontinuity. These authors also compared a custom triflange to a trabecular metal cup-cage construct finding similar implant costs of $12,500 and $11,250, respectively. All advocates of custom triflange acetabular components believe the results are similar or superior to other options in these very challenging cases at early follow-up. The primary disadvantage of the technique is the preoperative time required to manufacture the device – typically 4–8 weeks

We retrospectively reviewed 44 consecutive patients (50 hips) who underwent acetabular re-revision after a failed previous revision that had been performed using structural or morcellised allograft bone, with a cage or ring for uncontained defects. Of the 50 previous revisions, 41 cages and nine rings were used with allografts for 14 minor-column and 36 major-column defects. We routinely assessed the size of the acetabular bone defect at the time of revision and re-revision surgery. This allowed us to assess whether host bone stock was restored. We also assessed the outcome of re-revision surgery in these circumstances by means of radiological characteristics, rates of failure and modes of failure. We subsequently investigated the factors that may affect the potential for the restoration of bone stock and the durability of the re-revision reconstruction using multivariate analysis. At the time of re-revision, there were ten host acetabula with no significant defects, 14 with contained defects, nine with minor-column, seven with major-column defects and ten with pelvic discontinuity. When bone defects at re-revision were compared with those at the previous revision, there was restoration of bone stock in 31 hips, deterioration of bone stock in nine and remained unchanged in ten. This was a significant improvement (p <  0.001). Morselised allografting at the index revision was not associated with the restoration of bone stock. . In 17 hips (34%), re-revision was possible using a simple acetabular component without allograft, augments, rings or cages. There were 47 patients with a mean follow-up of 70 months (6 to 146) available for survival analysis. Within this group, the successful cases had a minimum follow-up of two years after re-revision. There were 22 clinical or radiological failures (46.7%), 18 of which were due to aseptic loosening. The five and ten year Kaplan–Meier survival rate was 75% (95% CI, 60 to 86) and 56% (95% CI, 40 to 70) respectively with aseptic loosening as the endpoint. The rate of aseptic loosening was higher for hips with pelvic discontinuity (p = 0.049) and less when the allograft had been in place for longer periods (p = 0.040). . The use of a cage or ring over structural allograft bone for massive uncontained defects in acetabular revision can restore host bone stock and facilitate subsequent re-revision surgery to a certain extent. Cite this article: Bone Joint J 2014;96-B:319–24

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs –. (A). Conventional cage ± structural or morselised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture, This reconstruction is used in young patients where restoration of bone stock is important. (B). Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. (C). Cup-Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup-cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven cup-cage procedures with an average follow-up of 74 months (range, 24–135 months; SD, 34.3) months were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Failure was defined as revision surgery for any cause, including infection. The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval, 83.1–97.4), and the 10-year survival rate was 85% (95% CI, 67.2–93.8). The Merle d'Aubigné-Postel score improved significantly from a mean of 6 pre-operatively to 13 post-operatively (p < 0.001). Four cup-cage constructs had non-progressive radiological migration of the ischial flange and they remain stable

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs –. (A) Conventional cage ± structural or morselised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture. This reconstruction is used in young patients where restoration of bone stock is important. (B) Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. (C) Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven cup-cage procedures with an average follow-up of 74 months (range, 24–135 months; SD, 34.3) months were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Failure was defined as revision surgery for any cause, including infection. The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval, 83.1–97.4), and the 10-year survival rate was 85% (95% CI, 67.2–93.8). The Merle d'Aubigné-Postel score improved significantly from a mean of 6 pre-operatively to 13 post-operatively (p < 0.001). Four cup-cage constructs had non-progressive radiological migration of the ischial flange and they remain stable

Aims. Few reconstructive techniques are available for patients requiring complex acetabular revisions such as those involving Paprosky type 2C, 3A and 3B deficiencies and pelvic discontinuity. Our aim was to describe the development of the patient specific Triflange acetabular component for use in these patients, the surgical technique and mid-term results. We include a description of the pre-operative CT scanning, the construction of a model, operative planning, and surgical technique. All implants were coated with porous plasma spray and hydroxyapatite if desired. Patients and Methods. A multicentre, retrospective review of 95 complex acetabular reconstructions in 94 patients was performed. A total of 61 (64.2%) were female. The mean age of the patients was 66 (38 to 85). The mean body mass index was 29 kg/m. 2. (18 to 51). Outcome was reported using the Harris Hip Score (HHS), complications, failures and survival. Results. The mean follow-up was 3.5 years (1 to 11). The mean HHS improved from 46 (15 to 90) pre-operatively to 75 (14 to 100). A total of 21 hips (22%) had at least one complication with some having more than one; including dislocation (6%), infection (6%), and femoral complications (2%). The implant was subsequently removed in five hips (5%), only one for suspected aseptic loosening. Conclusion. The Triflange patient specific acetabular component provides predictable fixation with complication rates which are similar to those of other techniques. Cite this article: Bone Joint J 2018;100-B(1 Supple A):50–4

First-time revision acetabular components have a 36% re-revision rate at 10 years in Australia, with subsequent revisions known to have even worse results. Acetabular component migration >1mm at two years following revision THA is a surrogate for long term loosening. This study aimed to measure the migration of porous tantalum components used at revision surgery and investigate the effect of achieving press-fit and/or three-point fixation within acetabular bone. Between May 2011 and March 2018, 55 patients (56 hips; 30 female, 25 male) underwent acetabular revision THR with a porous tantalum component, with a post-operative CT scan to assess implant to host bone contact achieved and Radiostereometric Analysis (RSA) examinations on day 2, 3 months, 1 and 2 years. A porous tantalum component was used because the defects treated (Paprosky IIa:IIb:IIc:IIIa:IIIb; 2:6:8:22:18; 13 with pelvic discontinuity) were either deemed too large or in a position preventing screw fixation of an implant with low coefficient of friction. Press-fit and three-point fixation of the implant was assessed intra-operatively and on postoperative imaging. Three-point acetabular fixation was achieved in 51 hips (92%), 34 (62%) of which were press-fit. The mean implant to host bone contact achieved was 36% (range 9-71%). The majority (52/56, 93%) of components demonstrated acceptable early stability. Four components migrated >1mm proximally at two years (1.1, 3.2, 3.6 and 16.4mm). Three of these were in hips with Paprosky IIIB defects, including 2 with pelvic discontinuity. Neither press-fit nor three-point fixation was achieved for these three components and the cup to host bone contact achieved was low (30, 32 and 59%). The majority of porous tantalum components had acceptable stability at two years following revision surgery despite treating large acetabular defects and poor bone quality. Components without press-fit or three-point fixation were associated with unacceptable amounts of early migration

The best treatment method of large acetabular bone defects at revision THR remains controversial. Some of the factors that need consideration are the amount of residual pelvic bone removed during revision; the contact area between the residual pelvic bone and the new implant; and the influence of the new acetabular construct on the centre of rotation of the hip. The purpose of this study was to compare these variables in two of the most used surgical techniques used to reconstruct severe acetabular defects: the trabecular metal acetabular revision system (TMARS) and a custom triflanged acetabular component (CTAC). Pre- and post-operative CT-scans were acquired from 11 patients who underwent revision THR with a TMARS construct for a Paprosky IIIB defect, 10 with pelvic discontinuity, at Royal Adelaide Hospital. The CT scans were used to generate computer models to virtually compare the TMARS and CTAC constructs using a semi-automated method. The TMARS construct model was calculated using postoperative CT scans while the CTAC constructs using the preoperative CT scans. The bone contact, centre of rotation, inclination, anteversion and reamed bone differences were calculated for both models. There was a significant difference in the mean amount of bone reamed for the TMARS reconstructions (15,997 mm. 3. ) compared to the CTAC reconstructions (2292 mm. 3. , p>0.01). There was no significant difference between overall implant bone contact (TMARS 5760mm. 2. vs CTAC 5447mm. 2. , p=0.63). However, there was a significant difference for both cancellous (TMARS 4966mm. 2. vs CTAC 2887mm. 2. , p=0.008) and cortical bone contact (TMARS 795mm. 2. vs CTAC 2560mm. 2. , p=0.001). There was no difference in inclination and anteversion achieved. TMARS constructs resulted on average in a centre of rotations 7.4mm more lateral and 4.0mm more posterior. Modelling of two different reconstructions of Paprosky IIIB defects demonstrated potential important differences between all variables investigated

Although the introduction of ultraporous metals in the forms of acetabular components and augments has substantially improved the orthopaedic surgeon's ability to reconstruct severely compromised acetabuli, there remain some revision THAs that are beyond the scope of cups, augments, and cages. In situations involving catastrophic bone loss, allograft-prosthetic composites or custom acetabular components may be considered. Custom components offer the potential advantages of immediate, rigid fixation with a superior fit individualised to each patient. These custom triflange components require a pre-operative CT scan with three-dimensional (3-D) reconstruction using rapid prototyping technology, which has evolved substantially during the past decade. The surgeon can fine-tune exact component positioning, determine location and length of screws, modify the fixation surface with, for example, the addition of hydroxyapatite, and dictate which screws will be locked to enhance fixation. The general indications for using custom triflange components include: (1) failed prior salvage reconstruction with cage or porous metal construct augments, (2) large contained defects with possible discontinuity, (3) known pelvic discontinuity, and (4) complex multiply surgically treated hips with insufficient bone stock to reconstruct using other means. The general indications for using custom triflange components include: (1) failed prior salvage reconstruction with cage or porous metal construct augments, (2) large contained defects with possible discontinuity, (3) known pelvic discontinuity, and (4) complex multiply surgically treated hips with insufficient bone stock to reconstruct using other means. We previously reported on our center's experience with 23 patients (24 hips) treated with custom triflange components with minimum 2-year follow-up. This method of reconstruction was used in a cohort of patients with Paprosky Type 3B acetabular defects, which represented 3% (30 of 955) of the acetabular revisions we performed during the study period of 2003 to 2012. At a mean follow-up of 4.8 years (range, 2.3–9 years) there were 4 subsequent surgical interventions: 2 failures secondary to sepsis, and 1 stem revision and 1 open reduction internal fixation for periprosthetic femoral fracture. There were 2 minor complications managed nonoperatively, but all of the components were noted to be well-fixed with no obvious migration or loosening observed on the most recent radiographs. Harris hip scores improved from a mean of 42 (SD ± 16) before surgery to 65 (SD ± 18) at latest follow-up (p<0.001). More recently, we participated in a multi-center study of 95 patients treated with reconstruction using custom triflange components who had a mean follow-up of 3.5 years. Pelvic defects included Paprosky Type 2C, 3A, 3B and pelvic discontinuity. Concomitant femoral revision was performed in 21 hips. Implants used a mean of 12 screws with 3 locking screws. Twenty of 95 patients (21%) experienced at least one complication, including 6% dislocation, 6% infection, and 2% femoral-related issues. Implants were ultimately removed in 11% of hips. One hip was revised for possible component loosening. Survivorship with aseptic loosening as the endpoint was 99%,. Custom acetabular triflange components represent yet another tool in the reconstructive surgeon's armamentarium. These devices can be helpful in situations of catastrophic bone loss, achieving reliable fixation. Clinical results are inferior to both primary THA and more routine revision THA. Patients and surgeons should be aware of the increased complications associated with these complex hip revisions

The treatment of extensive bone loss and massive acetabular defects is a challenging procedure, especially in cases with concomitant pelvic discontinuity (PD). Pelvic discontinuity describes the separation of the ilium proximally from the ischio-pubic region distally. The appropriate treatment strategy is to restore a stable continuity between the ischium and the ilium to reconstruct the anatomical hip center. Several treatment options such as antiprotrusio cages, metal augments, reconstruction cages with screw fixation, structural allograft with plating, jumbo cups, oblong cups and custom-made triflange acetabular components have been described as possible treatment options. Cage and/or ring constructs or acetabular allograft are commonly used techniques with unsatisfactory results and high failure rates. More favorable results have been presented with custom triflange acetabular components (CTAC), although the results are still unsatisfactory. Three-dimensional printing technology (3DP) has already become part of the surgical practice. In this context, preliminary clinical and radiological results using a 3D-printed custom acetabular component in the management of extensive acetabular defects are presented. The overall complication rate was 33.3 %. In one out of 15 patients (6.6 %), implant-associated complication occurred revealing an overall implant-associated survival rate of 93.3%. The 3D-printed custom acetabular component suggests a promising future, although the manufacturing process has high costs and the complication rate is still high

An uncemented hemispherical acetabular component is the mainstay of acetabular revision and gives excellent long-term results. Occasionally, the degree of acetabular bone loss means that a hemispherical component will be unstable when sited in the correct anatomical location or there is minimal bleeding host bone left for biological fixation. On these occasions an alternative method of reconstruction has to be used. A major column structural allograft has been shown to restore the deficient bone stock to some degree, but it needs to be off-loaded with a reconstruction cage to prevent collapse of the graft. The use of porous metal augments is a promising method of overcoming some of the problems associated with structural allograft. If the defect is large, the augment needs to be protected by a cage to allow ingrowth to occur. Cup-cage reconstruction is an effective method of treating chronic pelvic discontinuity and large contained or uncontained bone defects. . This paper presents the indications, surgical techniques and outcomes of various methods which use acetabular reconstruction cages for revision total hip arthroplasty. Cite this article: Bone Joint J 2016;98-B(1 Suppl A):73–7

Aims. It may not be possible to undertake revision total hip arthroplasty (THA) in the presence of massive loss of acetabular bone stock using standard cementless hemispherical acetabular components and metal augments, as satisfactory stability cannot always be achieved. We aimed to study the outcome using a reconstruction cage and a porous metal augment in these patients. Patients and Methods. A total of 22 acetabular revisions in 19 patients were performed using a combination of a reconstruction cage and porous metal augments. The augments were used in place of structural allografts. The mean age of the patients at the time of surgery was 70 years (27 to 85) and the mean follow-up was 39 months (27 to 58). The mean number of previous THAs was 1.9 (1 to 3). All patients had segmental defects involving more than 50% of the acetabulum and seven hips had an associated pelvic discontinuity. . Results. Three failures were observed in two hips, both of which had undergone a previous resection of a tumour affecting the acetabulum. Other complications included a late arterial injury, a sciatic nerve palsy, a dislocation treated with a femoral revision, a deep infection treated with irrigation and debridement and a fracture of the greater trochanter treated conservatively. The mean Oxford Hip Score significantly increased from 13.9 (2 to 23) to 28.7 (13 to 38) (p < 0.00001). The mean vertical distance between the centre of rotation of the hip and its normal location decreased from 30 mm to 10 mm. Conclusions. Acceptable early survivorship can be achieved using this novel technique, but it may be unsuitable for use in patients who have previously undergone the resection of a tumour involving the acetabulum. Cite this article: Bone Joint J 2017;99-B:607–13

Although the introduction of ultraporous metals in the forms of acetabular components and augments has substantially improved the orthopaedic surgeon's ability to reconstruct severely compromised acetabuli, there remain some revision THAs that are beyond the scope of cups, augments, and cages. In situations involving catastrophic bone loss, allograft-prosthetic composites or custom acetabular components may be considered. Custom components offer the potential advantages of immediate, rigid fixation with a superior fit individualised to each patient. These custom triflange components require a preoperative CT scan with three-dimensional (3-D) reconstruction using rapid prototyping technology, which has evolved substantially during the past decade. The surgeon can fine-tune exact component positioning, determine location and length of screws, modify the fixation surface with, for example, the addition of hydroxyapatite, and dictate which screws will be locked to enhance fixation. The general indications for using custom triflange components include: (1) failed prior salvage reconstruction with cage or porous metal construct augments, (2) large contained defects with possible discontinuity, (3) known pelvic discontinuity, and (4) complex multiply surgically treated hips with insufficient bone stock to reconstruct using other means. We previously reported on our center's experience with 23 patients (24 hips) treated with custom triflange components with minimum 2-year follow-up. This method of reconstruction was used in a cohort of patients with Paprosky Type 3B acetabular defects, which represented 3% (30 of 955) of the acetabular revisions we performed during the study period of 2003 to 2012. At a mean follow-up of 4.8 years (range, 2.3 – 9 years) there were four subsequent surgical interventions: two failures secondary to sepsis, and one stem revision and one open reduction internal fixation for periprosthetic femoral fracture. There were two minor complications managed nonoperatively, but all of the components were noted to be well-fixed with no obvious migration or loosening observed on the most recent radiographs. Harris hip scores improved from a mean of 42 (SD ±16) before surgery to 65 (SD ±18) at latest follow-up (p < 0.001). More recently, we participated in a multi-center study of 95 patients treated with reconstruction using custom triflange components who had a mean follow-up of 3.5 years. Pelvic defects included Paprosky Type 2C, 3A, 3B and pelvic discontinuity. Concomitant femoral revision was performed in 21 hips. Implants used a mean of 12 screws with 3 locking screws. Twenty of 95 patients (21%) experienced at least one complication, including 6% dislocation, 6% infection, and 2% femoral-related issues. Implants were ultimately removed in 11% of hips. One hip was revised for possible component loosening. Survivorship with aseptic loosening as the endpoint was 99%. Custom acetabular triflange components represent yet another tool in the reconstructive surgeon's armamentarium. These devices can be helpful in situations of catastrophic bone loss, achieving reliable fixation. Clinical results are inferior to both primary THA and more routine revision THA. Patients and surgeons should be aware of the increased complications associated with these complex hip revisions

Impaction grafting is an excellent option for acetabular revision. It is technique specific and very popular in England and the Netherlands and to some degree in other European centers. The long term published results are excellent. It is, however, technique dependent and the best results are for contained cavitary defects. If the defect is segmental and can be contained by a single mesh and impaction grafting, the results are still quite good. If, however, there is a larger segmental defect of greater than 50% of the acetabulum or a pelvic discontinuity, other options should be considered. Segmental defects of 25–50% can be managed by minor column (shelf) or figure of 7 structural allografts with good long term results. Porous metal augments are now a good option with promising early to mid-term results. Segmental defects of greater than 50% require a structural graft or porous augment usually protected by a cage. If there is an associated pelvic discontinuity then a cup cage is a better solution. An important question is does impaction grafting facilitate rerevision surgery? There is no evidence to support this but some histological studies of impacted allograft would suggest that it may. On the other hand there are papers that show that structural allografts do restore bone stock for further revision surgery. Also the results of impaction grafting are best in the hands of surgeons comfortable with using cement on the acetabular side, and one of the reasons why this technique is not as popular in North America

THA after acetabular fracture presents unique technical challenges. These challenges include bone deformity, bone deficiency, sclerotic or dysvascular bone, non-united bony fragments, pelvic discontinuity, retained hardware, heterotopic ossification, previous incisions, and concerns regarding the sciatic nerve. Despite these challenges, with current treatment methods, a high degree of success can be achieved with modern technology. Preoperative evaluation for infection - In previously operated acetabular fractures, infection is always a concern. Screening C-reactive protein and sedimentation rate may be performed. If a concern regarding infection is present, the hip may be aspirated; Incisions - In most cases, a previous incision may be utilised. If necessary, an incision may be extended or a new limb can be created and attention should be paid to maintaining optimal skin bridges. In cases with a high degree of concern about infection, a staged procedure may be considered. However, in most cases, hardware removal can be done selectively at the time of THA surgery. Hardware that does not compromise placement of the THA may be left in place. Sometimes hardware can be cut off within the acetabulum to minimise exposure needs. The reconstructive goal is to place the hip center as close as possible to normal hip center but also to gain good support of the socket on host bone. In most cases, both goals can be met. When necessary, some compromise in hip center of rotation may be considered to optimise implant stability on host bone. The principles of revision surgery are followed using uncemented acetabular components fixed with augmentation screws. Most bone deficiencies may be managed with methods similar to revision hip surgery. However, in the acetabular fracture patient, usually the host femoral head is available and this can be used as bone graft, either in particulate or bulk form. Most cavitary deficiencies can be dealt with particulate bone graft. Some superolateral bone deficiencies from posterior wall fractures may be considered for bone grafting or augmentation techniques. Nonunited fractures are not uncommon in these circumstances. Small wall nonunions may be managed as noted above for bone deficiency. If pelvic discontinuity is present, it is usually best treated by following the rules established for treatment of pelvic discontinuity with pelvic plating. Pelvic plating provides a reasonable likelihood of bone healing in these circumstances when combined with bone grafting techniques. Heterotopic ossification is common in previously operated acetabular fractures. Removal of heterotopic bone at the time of surgery to gain hip motion is routine. Postoperative measures to reduce the likelihood of bone formation (that is either shielded radiation or use of a nonsteroid anti-inflammatory agent) may be strongly considered. The sciatic nerve is at risk during these procedures. In many cases, avoiding the nerve and the region of the nerve is a reasonable approach. When a lot of work must be done on the posterior column, the surgeon needs to know exactly where the nerve is and in such cases the nerve may be exposed distally beneath the gluteus maximus tendon and followed proximally with careful and judicious dissection. Results of total hip arthroplasty after acetabular fracture have varied in the past. More recent series have shown a high rate of acetabular fixation associated with uncemented hemispherical implants. Acetabular fracture patients are disproportionately young and active with unilateral hip disease and, therefore, bearing surfaces should be chosen accordingly

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs:. (A). Conventional cage ± structural or morselised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture. This reconstruction is used in young patients where restoration of bone stock is important. (B). Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. (C). Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs –. Conventional cage ± structural or morselised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture. This reconstruction is used in young patients where restoration of bone stock is important. Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity

Detection of clinical situations are the most difficult for primary THA and factors which determine the complexity. Results of 2368 primary THA performed by one surgeon in 1923 patients with various hip pathologies from 2004 to 2016 were analyzed. The time of the surgery, the bloodloss, the features of the surgical technique, the implants used, and the incidence of complications and revisions were assessed and X-ray analysis was performed. Difficult cases of primary hip arthroplasty include severe dysplasia (types B2, C1, and C2 according to the Hartofilakidis classification), post-traumatic segmental acetabular defects and pelvic discontinuity, protrusio acetabuli, iatrogenic bone ankylosis and consequences of proximal femur fractures with significant shortening of the limb. X-ray signs of difficulty included an interruption of the Shenton line of 2 cm or more (except for acute fractures of proximal femur), the femoral neck-shaft angle less than 100°, and the horizontal distance from Kohler line to center of rotation less than 20% of the diameter of the femoral head. An additional burdening factor is the previous surgical interventions on the hip joint. The ten-year survival rate for standard cases was 94.9%, and for complex cases − 92.3%. The odds ratio development of complications in complex cases compared to standard cases is OR = 8.402 (95% CI from 4.614 to 15.300). In standard cases mean HHS increased from 42.9 points before surgery to 95.3 after surgery. In complex cases mean HHS before surgery was 38.9 and after surgery improved to 81.6 points, p <0.001. The complexity of the operation cannot be determined on the basis of only the etiological factor, it is necessary to take into account the severity of anatomical changes

First-time revision acetabular components have a 36% re-revision rate at 10 years in Australia, with subsequent revisions known to have even worse results. Acetabular component migration >1mm at two years following revision THA is a surrogate for long term loosening. This study aimed to measure the migration of porous tantalum components used at revision surgery and investigate the effect of achieving press-fit and/or three-point fixation within acetabular bone. Between May 2011 and March 2018, 55 patients (56 hips; 30 female, 25 male) underwent acetabular revision THR with a porous tantalum component, with a post-operative CT scan to assess implant to host bone contact achieved and Radiostereometric Analysis (RSA) examinations on day 2, 3 months, 1 and 2 years. A porous tantalum component was used because the defects treated (Paprosky IIa:IIb:IIc:IIIa:IIIb; 2:6:8:22:18; 13 with pelvic discontinuity) were either deemed too large or in a position preventing screw fixation of an implant with low coefficient of friction. Press-fit and three-point fixation of the implant was assessed intra-operatively and on postoperative imaging. Three-point acetabular fixation was achieved in 51 hips (92%), 34 (62%) of which were press-fit. The mean implant to host bone contact achieved was 36% (range 9–71%). The majority (52/56, 93%) of components demonstrated acceptable early stability. Four components migrated >1mm proximally at two years (1.1, 3.2, 3.6 and 16.4mm). Three of these were in hips with Paprosky IIIB defects, including 2 with pelvic discontinuity. Neither press-fit nor three-point fixation was achieved for these three components and the cup to host bone contact achieved was low (30, 32 and 59%). The majority of porous tantalum components had acceptable stability at two years following revision surgery despite treating large acetabular defects and poor bone quality. Components without press-fit or three-point fixation were associated with unacceptable amounts of early migration

Revision of total hip arthroplasty (THA) is being performed with increasing frequency. However, outcomes of repeated revisions have been rarely reported in the literature, especially for severe defects. Cup revision can be a highly complex operation depending on the bone defect. In acetabular defects like Paprosky types 1 and 2 porous cementless cups maybe fixed with screws give good results. Modern trabecular metal designs improve these good results. Allografts are useful for filling cavitary defects. In acetabular defects Paprosky types 3A and 3B, impacted morselised allografts with a cemented cup technique produce good results. Difficult cases with pelvic discontinuity require reconstruction of the acetabulum with acetabular plates or large cup-cages to solve these difficult problems. However, there is still no consensus regarding the best option for reconstructing hips with bone loss. Although the introduction of ultraporous metals has significantly increased the surgeon's ability to reconstruct severely compromised hips, there remain some that cannot be managed readily using cups, augments, or cages. In such situations custom acetabular components may be required. Individual implants represent yet another tool for the reconstructive surgeon. These devices can be helpful in situations of catastrophic bone loss. Ensuring long-term outcome mechanical stability has a greater impact than restoring an ideal center of rotation. We have done so far 15 3D Printed Individual Implants. All of them where Paprosky Type 3B defects, 10 with a additional pelvis discontinuity. The mean follow-up is 18 months. All implanted devices are still in place, no infection, no loosening. However, despite our consecutive case series, there are no mid- to long-term results available so far. Re-revision for failed revision THA acetabular components is a technically very challenging condition. The 3D Printed Individual Implants have a lot of advantages, like excellent surgical planning and a very simple technique (operative time, blood loss, instruments). They are a very stable construct for extensive acetabular defects and pelvic discontinuity

We investigated the detailed anatomy of the gluteus maximus, gluteus medius and gluteus minimus and their neurovascular supply in 22 hips in 11 embalmed adult Caucasian human cadavers. This led to the development of a surgical technique for an extended posterior approach to the hip and pelvis that exposes the supra-acetabular ilium and preserves the glutei during revision hip surgery. Proximal to distal mobilisation of the gluteus medius from the posterior gluteal line permits exposure and mobilisation of the superior gluteal neurovascular bundle between the sciatic notch and the entrance to the gluteus medius, enabling a wider exposure of the supra-acetabular ilium. This technique was subsequently used in nine patients undergoing revision total hip replacement involving the reconstruction of nine Paprosky 3B acetabular defects, five of which had pelvic discontinuity. Intra-operative electromyography showed that the innervation of the gluteal muscles was not affected by surgery. Clinical follow-up demonstrated good hip abduction function in all patients. These results were compared with those of a matched cohort treated through a Kocher–Langenbeck approach. Our modified approach maximises the exposure of the ilium above the sciatic notch while protecting the gluteal muscles and their neurovascular bundle. Cite this article: Bone Joint J 2014;96-B:48–53

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs –. (A) Conventional cage ± structural or morsellised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture. This reconstruction is used in young patients where restoration of bone stock is important. (B) Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. (C) Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs: (A) Conventional cage ± structural or morselised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture. This reconstruction is used in young patients where restoration of bone stock is important; (B) Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage; (C) Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity

Introduction:. Jumbo cups (58 mm or larger diameter in females and 62 mm or larger diameter in males), theoretically have lowered the percentage of bleeding bone that is required for osseointegration in severe acetabular defects. The purpose of this study was to analyze the safety and efficacy of Tritanium jumbo cups in patients with major acetabular defects (Paprosky type IIIa and IIIb) and assess the extent of osseointegration. Material and Methods:. From February 2007 and August 2010, 28 consecutive hips (26 patients, mean age of 69 years) underwent acetabular revision arthroplasty for treatment of Paprosky type IIIa and IIIb defects using Tritanium jumbo cups (Stryker, Mahwah, New Jersey). Results:. 14% of the hips had pelvic discontinuity. There was no intra-operative fracture. The initial stability was achieved in all hips, supplemented by screws. No Tantalum augments or bulk bone grafts were used in any of the cases. At mean follow-up of 4 years, there were no failures due to loosening or cup migration. Radiographic assessment showed osseointegration in all cups, ranging from 30% to 75% of the cup surface area as assessed in both anteroposterior and false profile views in Charnley zones I through VI. Discussion and conclusion:. In Paprosky type IIIb defect with pelvic discontinuity, jumbo cup can be used safely without the use of any augments. In pelvic dissociation, the fibrous tissue is stretched with jumbo cups in an under-reamed socket to achieve a fixation by distraction, especially in failed cemented sockets

Major bone loss involving the acetabulum can be seen during revision THA due to component loosening, migration or osteolysis and can also occur as a sequela of infected THA. Uncemented porous ingrowth components can be used for reconstruction of the vast majority of revision cases, where smaller segmental or cavitary defects are typically present. But when stable structural support on host bone is lacking, highly porous metal acetabular augments have been described as an alternative to large structural allograft, avoiding the potential for later graft resorption and the resulting loss of mechanical support that can follow. The fundamental concept behind these acetabular augments is the provision of critical additional fixation, structural support and increased contact area against host bone over the weeks following surgery while the desired ingrowth into porous implant surfaces is occurring. Technique: Three separate patterns of augment placement have been utilised in our practice since the development of these implants: Type 1 - augment screwed onto the superolateral acetabular rim in a “flying buttress” configuration for treatment of a segmental rim defect, Type 2 – augment placed superiorly against host and then fixed (with cement) to the acetabular component adjacent to the cup to fill a mainly elliptical cavitary defect, and Type 3 – augment(s) placed medial to the cup to fill a protrusio type cavitary or combined cavitary segmental defect of the superomedial or medial wall, and allow peripheral cup placement against the still intact acetabular rim. In all cases the acetabular component and augment interface is fixed together with cement, with care to prevent any cement extrusion between any implant and the bone. When possible, we now prefer to place the acetabular component first and fix it provisionally with 2 or more screws, and then place the augments second as this is technically quicker and easier. This order of insertion is only possible though in type 1 and a few select type 2 cases. Type 3 cases always require placement of one or more augments first, before cup insertion. Supplemental cancellous bone graft is used routinely. Results: From 2000 through 2007, porous tantalum acetabular augments were used very selectively in 85 revision THA procedures out of total of 1,789 revision hip cases performed at our institution in that time frame. All cases had associated massive acetabular deficiency precluding stable mechanical support for a cup alone. Fifty-eight hips had complete radiographic as well as clinical follow at minimum 5 years. The majority of patients had either Paprosky type 3A defects (28/58, 48%) or 3B defects (22/58, 38%). Ten out of 58 had pre-operative pelvic discontinuities. At 5 years, 2/58 (3%) were revised for aseptic loosening and another 6/58 demonstrated incomplete radiolucencies between the acetabular shell and zone 3. One of the revised cups and 5 of 6 of the cups with radiolucencies had an associated pelvic discontinuity. Summary: Highly porous metal acetabular augments are an infrequently needed, but extremely valuable, versatile and reliable adjunctive fixation method for use with uncemented acetabular components during complex revision THA associated with major bone deficiency. Intermediate term durability and apparent radiographic incorporation has been very good despite the complex reconstructions originally required. This technique can allow the avoidance of structural bone grafting for even the most massive of bone defect problems, but additional followup is needed to see how durable these encouraging results are over the longer term

Introduction: Uncemented sockets have been used for revision with good results in the literature. Tantalum coated acetabular uncemented implant is the next generation implant. We used Tritanium (Stryker Corp. Kalamazoo, USA) for revision of acetabulum and present the early results. Aim: To determine early results of porous tantalum coated modular acetabular cups in revision hip arthroplasty. Patients and methods:41 acetabular revisions in 41 patients were performed using Tritanium acetabular uncemented sockets between March 2007 and March 2008. Posterior approach was used for all procedures. AAOS system for acetabular bone deficiency and Harris hip score for function was used for assessment. Results: Mean age of the patients was 67 yrs (range 45–88). 95% of cups were fixed with screws for initial stability. AAOS classification showed there were 17 % Type 1, 49 % Type 2, 24% Type 3 and 5% Type 4 defects and 5 % had no defect. Bone graft was used to in 70% of patients, mostly autograft from the reamings. Mean Harris Hip Score improved from 68 pre-operatively to 84 at the last follow-up. Cup integration was seen in 93% patients. In two patients with pelvic discontinuity there was migration and in one loosening of the implant. One patient was treated for deep vein thrombosis and one patient for infection. Conclusion: Early results of tantalum coated acetabular socket are encouraging, in providing adequate initial stabilisation for biologic fixation in segmental, cavitatory and combined defects. Facility to use locking screws in multiple directions may help in addressing pelvic discontinuity

We investigated the early results of modular porous metal components used in 23 acetabular reconstructions associated with major bone loss. The series included seven men and 15 women with a mean age of 67 years (38 to 81), who had undergone a mean of two previous revisions (1 to 7). Based on Paprosky’s classification, there were 17 type 3A and six type 3B defects. Pelvic discontinuity was noted in one case. Augments were used in 21 hips to support the shell and an acetabular component-cage construct was implanted in one case. At a mean follow-up of 41 months (24 to 62), 22 components remained well fixed. Two patients required rerevision of the liners for prosthetic joint instability. Clinically, the mean Harris Hip Score improved from 43.0 pre-operatively (14 to 86) to 75.7 post-operatively (53 to 100). The mean pre-operative Merle d’Aubigné score was 8.2 (3 to 15) and improved to a mean of 13.7 (11 to 18) post-operatively. These short-term results suggest that modular porous metal components are a viable option in the reconstruction of Paprosky type 3 acetabular defects. More data are needed to determine whether the system yields greater long-term success than more traditional methods, such as reconstruction cages and structural allografts

Major bone loss involving the acetabulum can be seen during revision THA due to component loosening, migration or osteolysis and can also occur as a sequela of infected THA. Uncemented porous ingrowth components can be used for reconstruction of the vast majority of revision cases, where smaller segmental or cavitary defects are typically present. But when stable structural support on host bone is lacking, highly porous metal acetabular augments have been described as an alternative to large structural allograft. The fundamental concept behind these acetabular augments is the provision of critical additional fixation, structural support and increased contact area against host bone over the weeks following surgery while the desired ingrowth into porous implant surfaces is occurring. Three separate patterns of augment placement have been utilised in our practice since the development of these implants a decade ago: Type 1 - augment screwed onto the superolateral acetabular rim in a “flying buttress” configuration for treatment of a segmental rim defect, Type 2 – augment placed superiorly against host and then fixed to the acetabular component adjacent to the cup to fill a mainly elliptical cavitary defect, and Type 3 – augment(s) placed medial to the cup to fill a protrusio type cavitary or combined cavitary segmental defect of the superomedial or medial wall, and allow peripheral cup placement against the still intact acetabular rim. In all cases the acetabular component and augment interface is fixed together with cement, with care to prevent any cement extrusion between any implant and the bone. When possible, we now prefer to place the acetabular component first and fix it provisionally with 2 or more screws, and then place the augments second as this is technically quicker and easier. This order of insertion is only possible in type 1 and a few select type 2 cases. Type 3 cases always require placement of one or more augments first, before cup insertion. Supplemental cancellous bone graft is used routinely, but the need for structural bone is avoided. From 2000 through 2007, porous tantalum acetabular augments were used very selectively in 85 revision THA procedures out of total of the 1,789 revision hip cases performed at our institution. All cases had associated massive acetabular deficiency precluding stable mechanical support for a cup alone. Fifty-eight hips had complete radiographic and clinical follow at minimum 5 years. The majority of patients had either Paprosky type 3A defects (28/58, 48%) or 3B defects (22/58, 38%). Ten out of 58 had pre-operative pelvic discontinuities. Three separate patterns of augment placement were utilised: Type 1 - augment screwed onto the superolateral acetabular rim (21%), Type 2 – augment fixed to the acetabular component adjacent to the cup to fill a mainly elliptical cavitary defect (34%), and Type 3 – augment(s) placed medial to the cup to fill a protrusio type cavitary or combined cavitary segmental defect of the superomedial medial wall (45%). At 5 years, 2/58 (3%) were revised for aseptic loosening and another 6/58 demonstrated incomplete radiolucencies between the acetabular shell and zone 3. One of the revised cups and 5 of 6 of the cups with radiolucencies had an associated pelvic discontinuity. Highly porous metal acetabular augments are an infrequently needed, but extremely valuable, versatile and reliable adjunctive fixation method for use with uncemented acetabular components during complex revision THA associated with major bone deficiency. Smaller patients are more likely to require this approach as reaming away defects to allow insertion of a jumbo cup is more difficult with a smaller AP dimension to the acetabular columns and less local bone for implant support. Intermediate term durability and apparent radiographic incorporation has been very good despite the complex reconstructions originally required. This technique can allow the avoidance of structural bone grafting for even the most massive of bone defect problems, but additional followup is needed to see how durable these encouraging results are over the longer term

Aim: The purpose of this study was to assess the results with use of an oval cementless acetabular component for revision total hip arthroplasty. Methods: 30 hips had an acetabular revision with an cementless oval acetabular component. No patient was lost to follow-up, but one died during the study period. All defects were classiþed during surgery according the AAOS classiþcation. All patients were evaluated radiographically and clinically and were followed for an average of thirty-six months (range, twenty four to fourty eight months). In 21 of the 30 hips no additional bone grafting was necessary. Results: There were 17 segmental defects (type 1), 12 combined defects (type III) and one case of pelvic discontinuity (type IV). At the time of follow-up, 27 (93.1%) of 29 cups were stable. One of the loosening affected the patient with pelvic discontinuity, the other a patient with a combined segmental defect including the medial wall. The average Harris Hip Score improved from 39 points (range: 15–73 points) preoperatively to 89 points (range 68–96 points) postoperatively. Complications included three dislocations without recurrency. The radiological follow-up examinations revealed good osteointegration of 27 implants. All postoperatively remaining defects were completly þlled in by bone at the follow up. Conclusion: The asymmetrical shape of the BOFOR enhanced the primary stabilty on the lateral columns with three point anchorage. We recommend this device when a patient has an oblong-shaped acetabular defect and the surgeon wants to correct an elevated hip center. However, the medial wall of the acetabulum (Kohlerñs line) should be intact

The treatment of extensive bone loss and massive acetabular defects is a challenging procedure, especially the concomitant pelvic discontinuity (PD) can be compounded by several challenges and pitfalls. The appropriate treatment strategy is to restore a stable continuity between the ischium and the ilium and to reconstruct the anatomical hip center. Antiprotrusio cages, metal augments, reconstruction cages with screw fixation, structural allograft with plating, jumbo cups, oblong cups and custom-made triflange acetabular components have been reported as possible treatment options. Nevertheless, the survivorship following acetabular revision with extensive bone loss is still unsatisfactory. The innovation of three-dimensional printing (3DP) has become already revolutionary in engineering and product design. Nowadays, the technology is becoming part of surgical practice and suitable for the production of precise and bespoke implants. The technique of a 3D-printed custom acetabular component in the management of extensive acetabular defect is presented

Introduction. Acetabular revision surgery is challenging due to severe bone defects. Burch-Schneider anti-protrusion cages (BS cage: Zimmer-Biomet) is one of the options for acetabular revision, however higher dislocation rate was reported. A computed tomography (CT)-based navigation system indicates us the planned direction for implantation of a cemented acetabular cup during surgery. A large diameter femoral head is also expected to reduce the dislocation rate. The purpose of this study is to investigate short-term results of BS cage in acetabular revision surgery combined with the CT-based navigation system and the use of large diameter femoral head. Methods. Sixteen hips of fifteen patients who underwent revision THA using allografts and BS cage between September 2013 and December 2017 were included in this study with the follow-up of 2.7 (0.1–5.0) years. There were 12 women and three men with a mean age of 78.6 years (range, 59–61 years). The cause of acetabular revision was aseptic loosening in all hips. The failed acetabular cup was carefully removed, and acetabular bone defect was graded using the Paprosky classification. Structural allografts were morselized and packed for all medial or contained defects. In some cases, solid allograft was implanted for segmental defects. BS cage was molded to optimize stability and congruity to the acetabulum and fixed with 6.5 mm titanium screws to the iliac bone. The inferior flange was slotted into the ischium. The upside-down trial cup was attached to a straight handle cup positioner with instrumental tracker (Figure 1) and placed on the rim of the BS cage to confirm the direction of the target angle for cement cup implantation under the CT-based navigation system (Stryker). After removing the cement spacer around the X3 RimFit cup (Stryker) onto the BS cage for available maximum large femoral head, the cement cup was implanted with confirming the direction of targeting angle. Japanese Orthopedic Association score (JOA score) of the hip was used for clinical assessment. Implant position, loosening, and consolidation of allograft were assessed using anterior and lateral radiographies of the pelvis. Results. Fifteen hips had a Paprosky IIIB defect, and one hip had a pelvic discontinuity. JOA score significantly improved postoperatively. No radiolucent lines and no displacement of BS cage could be found in 9 of 15 hips. Consolidation of allografts above the protrusion cage was observed in these patients. Displacement of BS cage (>5mm) was observed in 6 hips and displacement was stopped with allograft consolidation in 5 of 6 hips. The other patient showed lateral displacement of BS cage and underwent revision surgery. Average cup inclination and anteversion angles were 37.7±5.0 degree and 24.6±7.2 degree, respectively. 12 of 16 patients were included in Lewinnek's safe zone. One patient with 32 mm diameter of the femoral head had dislocation at 17 days postoperatively. All patients who received ≥36mm diameter of femoral head showed no dislocation. Conclusions. CT-based navigation system and the use of large femoral head may influence the prevention of dislocation in the acetabular revision surgery with BS cage for severe acetabular bone defects

We present here a case of pseudotumor formation likely due to metal wear debris generated at the head-neck taper (trunnion) of the femoral stem and head components in a metal-on-highly cross-linked polyethylene (MOP) total hip arthroplasty. Over the last few years, this recently described diagnosis, trunnionosis, is being recognized and reported more frequently. This patient presented with a rather large (12 cm diameter) pseudotumor with accompanying loss of abductors and a pelvic discontinuity making reconstruction more challenging. We believe the psuedotumor in this patient developed from trunnionosis. This is an interesting case of aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL) in a MOP total hip arthroplasty

Pathologic fractures about the hip are an uncommon, but increasingly prevalent, clinical scenario encountered by orthopaedic surgeons. These fractures about the hip usually necessitate operative management. Life expectancy must be taken into account in management, but if survivorship is greater than 1 month, operative intervention is indicated. Determination must be made prior to operative management if the lesion is a solitary or metastatic lesion. Imaging of the entire femur is necessary to determine if there are other lesions present. Bone lesions that have a large size, permeative appearance, soft tissue mass, and rapid growth are all characteristics that suggest an aggressive lesion. Biopsy of the lesion in coordination with the operative surgeon should be conducted if the primary tumor is unknown. Metastatic disease is much more common than primary tumors in the adult population. Many metastatic fractures in the intertrochanteric region, and all fractures in the femoral neck and head are an indication for hemiarthroplasty or total hip arthroplasty. Cemented femoral implants are generally indicated. This allows immediate weight bearing in a bone with compromised bone stock, thus reducing the risk of peri-operative fractures. Additionally, patients are often treated with radiation and/or chemotherapy, which may prevent proper osseointegration of an ingrowth femoral component. Highly porous ingrowth shells have been shown to provide reliable and durable fixation even in these situations. Management of a periacetabular pathologic fracture, particularly resulting in a pelvic discontinuity is a particularly challenging situation. Use of a highly porous acetabular component combined with an acetabular cage, a custom acetabular component, a cemented Harrington technique, or a primary acetabular reconstruction cage may be utilised. Patients with neoplastic disease are often at risk for infection and thromboembolic disease both from the disease and treatment. Pre-operative evaluation of nutrition status by measuring albumin and pre-albumin will give the surgeon insight. Additionally, dehydration is commonly seen in cancer patients, and adequate pre-operative optimization of fluids and electrolytes may reduce peri-operative complications from other organ systems

Highly porous tantalum cups have been used in complex acetabular revisions for nearly 20 years but reports of long term results are limited. This study was designed to report ten year results of revision using a single porous tantalum cup design with special attention to re-operation for any reason, all-cause revision, and revision for aseptic loosening. Retrospective review of all revision THA cases performed from 1999–2006 using a highly porous tantalum acetabular component design with multiple screw holes and a cemented polyethylene liner (Zimmer Biomet, Warsaw, IN). Our institutional medical record and total joint registry were used to assess follow-up and xrays were reviewed. The Paprosky classification system was used to rate acetabular bone loss. Radiographic loosening was defined as new/progressive radiolucencies in all 3 acetabular zones, or cup migration (>2mm). Kaplan-Meier survivorship was used to assess survivorship free of cup revision/removal for any reason, and free of revision for aseptic loosening. Between 1999 and 2006 this tantalum cup was used in 916 revisions. Mean age: 66 (±6), BMI: 29 (±6), and male: 42%. Indications for revision: aseptic loosening 346 (38%), osteolysis 240 (26%), and infected arthroplasty 168 (18%). Large (3A or 3B) bone defects were present in 260, and pelvic discontinuity in 61. Reoperation for any reason: 133 (15%), but 84 of 133 cases did not require cup revision for instability (38) or femoral failure (24). Tantalum cup removal/revision was required in 49 (5.3%) for deep infection (39) and recurrent dislocation (6), and aseptic loosening (4). 10 year survivorship free of cup revision for any reason: 95% and for aseptic loosening: 99%. Radiographic review (mean 10 years): suspicious for aseptic loosening in another 4 cups. A highly porous tantalum acetabular component with multiple screws and a cemented polyethylene insert provided durable long term fixation for an array of acetabular revision problems. Long term aseptic loosening was very rare (<1%) and cup removal was mainly related to deep infection, and rarely dislocation

Revision of total hip arthroplasty (THA) is being performed with increasing frequency. However, outcomes of repeated revisions have been rarely reported in the literature, especially for severe defects. Cup revision can be a highly complex operation depending on the bone defect. In acetabular defects like Paprosky types 1 and 2 porous cementless cups fixed with screws give good results. Modern trabecular metal designs improve these good results. Allografts are useful for filling cavitary defects. In acetabular defects Paprosky types 3A and 3B, especially the use of trabecular metal cups, wedges, buttresses and cup-cage systems can produce good results. Difficult cases in combination with pelvic discontinuity require reconstruction of the acetabulum with acetabular plates or large cup-cages to solve these difficult problems. However, there is still no consensus regarding the best option for reconstructing hips with bone loss. Although the introduction of ultraporous metals has significantly increased the surgeon's ability to reconstruct severely compromised hips, there remain some that cannot be managed readily using cups, augments, or cages. In such situations custom acetabular components may be required. Individual implants represent yet another tool for the reconstructive surgeon. These devices can be helpful in situations of catastrophic bone loss. Ensuring long-term outcome, mechanical stability has a greater impact than restoring an ideal center of rotation. However, despite our consecutive case series there are no mid- to long-term results available so far. Re-revision for failed revision THA acetabular components is a technically very challenging condition

Introduction. Acetabular fractures management is controversial since, despite a good anatomical reduction, clinical outcome is not satisfactory very often and the probability of a total hip arthroplasty (THA) is high. Surgical treatment include long operating times, large approach, blood loss, neural and muscle damage, and a high risk of failure and secondary osteoarthritis related to bone necrosis, cartilage damage, and bone loss. We hypothesized that the acetabular fracture management affected the clinical and radiological outcome of THA after posttraumatic arthritis. Materials and Methods. We compared 49 patients (49 hips) initially treated conservatively followed some months later by THA in conjunction with acetabular reconstruction (group 1); and 29 patients (29 hips) who had undergone THA after a failed osteosynthesis (group 2). There were more associated fractures according to Letournel in group 2. The mean age was 59.3±15.8 years for group 1 and 52.9±15.2 years for group 2. The mean delay between fracture and THA was 75.4±5 months for group 1 and 59.4±5 for group 2. The mean follow-up was 11.7 in group 1 and 10.2 in group 2. Preoperative bone defect was similar. We used bone autograft in 13 hips (26.5%) in group 1 and four (13.6%) in group 2. We used acetabular reconstruction plates in 2 hips with a pelvic discontinuity in group 1. Complications, clinical outcome according to Harris Hip Score, and radiological reconstruction were compared. Two-way ANOVA with repeated measures were used for comparison. Results. There were 5 cups revised for aseptic loosening in group 1 and 2 in group 2. The cumulative probability of not having a cup revision at 16 years was 90.6% (95% confidence interval (CI) 78,1 to 100) for group 1 and 94.1% (95% CI 86.5 to 100) for group 2 (p=0.76). There were 4 sciatic palsies in group 2, 4 of which developed after trauma and 2 after osteosynthesis. There were no infections. Although pre-operative clinical score was better in group 1, post-operatively at latest follow-up there were no differences. The radiological reconstruction was better in group 1 for version angle (p=0.03) and abductor lever arm (p=0.02). The change from the pre- to post-operative situation was greater in group 2 for the latter (Delta value, p=0.002). The rate of post-operative heterotopic ossifications was greater in group 2 (p=0.04). Conclusions. Long-term clinical and radiograph results are good in patients who underwent THA after a complex acetabular fracture, however, primary THA in conjunction with acetabular reconstruction had a lower number of complications and a better radiographic acetabular reconstruction than a THA after failed osteosynthesis

3D imaging is commonly employed in the surgical planning and management of bony deformity. The advent of desktop 3D printing now allows rapid in-house production of specific anatomical models to facilitate surgical planning. The aim of this pilot study was to evaluate the feasibility of creating 3D printed models in a university hospital setting. For requested cases of interest, CT DICOM images on the local NHS Picture Archive System were anonymised and transferred. Images were then segmented into 3D models of the bones, cleaned to remove artefacts, and orientated for printing with preservation of the regions of interest. The models were printed in polylactic acid (PLA), a biodegradable thermoplastic, on the CubeX Duo 3D printer. PLA models were produced for 4 clinical cases; a complex forearm deformity as a result of malunited childhood fracture, a pelvic discontinuity with severe acetabular deficiency following explantation of an infected total hip replacement, a chronically dislocated radial head causing complex elbow deformity as a result of a severe skeletal dysplasia, and a preoperative model of a deficient proximal tibia as a result of a severe tibia fracture. The models materially influenced clinical decision making, surgical intervention planning and required equipment. In the case of forearm an articulating model was constructed allowing the site of impingement between radius and ulnar to be identified, an osteotomy was practiced on multiple models allowing elimination of the block to supination. This has not previously been described in literature. The acetabulum model allowed pre-contouring of a posterior column plate which was then sterilised and eliminated a time consuming intraoperative step. While once specialist and expensive, in house 3D printing is now economically viable and a helpful tool in the management of complex patients

Total hip arthroplasty continues to be one of the most effective procedures. Aseptic loosening compromises the long term outcome of this otherwise successful procedure. Large hemispherical cups may be used during revision surgery for patients with severe bone loss. Acetabular revision with cementless components has been remarkably successful with some series reporting no revisions for aseptic loosening at an average follow-up of 13.9 years. Another study on 186 patients (196 hips) receiving jumbo acetabular components, noted a survivorship of 98% at 4 years and 96% at 16 years. Cementless acetabular revision is now feasible for a wide range of revision situations, including some cases of pelvic discontinuity. The Paprosky classification is useful in predicting the reconstructive technique that will be required. Type I and many Type II defects may be reconstructed with standard cementless components. Many Type II and Type III defects, which involve the loss of additional structural bone, can be reconstructed with a jumbo cup. A jumbo cup is defined by Whaley et al. as a component that is >61 mm in women and >65 mm in men, a definition that is based on a shell that is >10 mm greater than the average diameter cup implanted in women and men. The jumbo cup has the advantage of an increased contact area between host bone and cup which maximises the surface area for ingrowth or ongrowth. The increased area of contact also prevents cup migration by allowing for force dissipation over a large area. Use of a jumbo cup may also decrease the need to use bone graft. In contrast to positioning the cup in the so-called high hip center, a jumbo cup can help to restore the hip center of rotation. The disadvantages of this technique are that host bone may have to be removed to implant the cup, that bone stock is not restored by the reconstruction, and that hemispherical cups have limited applicability in situations of oblong bone stock deficiency. Jumbo acetabular components can be used in combination with both structural and cancellous bone graft. In these cases, the cementless cup must achieve adequate contact with host bone in order to allow bone ingrowth to occur

Reoperation on the acetabular side of the total hip arthroplasty construct because of acetabular liner wear with or without extensive osteolysis is the most common reoperation performed in revision hip surgery today. The options of revision of the component or component retention, liner exchange (cemented or direct reinsertion) and bone grafting represent a classic surgeon dilemma of choices and compromises. CT scanning is helpful in determining the size and location of osteolytic lesions. My preference is to retain the existing shell when possible especially when there are large osteolytic lesions but where structural support is maintained. The advantages of complete revision are easy access to lytic lesions, ability to change component position and the ability to use contemporary designs with optimal bearing surfaces (for wear and dislocation prevention). The disadvantage is bone disruption including pelvic discontinuity with component removal (less so with Explant Systems) and difficult reconstructions due to excessive bone loss from the osteolytic defects (sometimes requiring cup cages). The advantage of component retention is that structural integrity of the pelvis is maintained and in general, a higher quality polyethylene is utilised. For large lesions I use windows to debride and bone graft the lesions. If the locking mechanism is inadequate, cementing a liner, including a constrained liner in some cases, that has been scored in a spider web configuration provides durable results at 5-year follow-up. The downside to liner exchange is potential instability. We immobilise all liner exchange patients postoperatively

Segmental defects of the acetabulum are often encountered in revision surgery. Many times these can be handled with hemispherical cups. However when larger defects are encountered particularly involving the dome and/or posterior wall structural support for the cup is often needed. In the past structural allograft was used but for the last 12 years at our institution trabecular metal augments have been used in the place of structural allograft in all cases. This talk will focus on technique and mid-term results using augments in association with an uncemented revision shell. The technique can be broken down into 6 steps outlined below: 1. Exposure, 2. Reaming, 3. Trialing, 4. Augment Inserted, 5. Cup Insertion/Stabilization, 6. Trial Reduction/Liner Cementation. A recent study was undertaken to assess the mid-term results of this technique. We prospectively followed the first 56 patients in whom these augments were utilised in combination with a trabecular metal acetabular component in our unit. Details of this study will be presented. The median follow up of the surviving patients was 110 months (range 88–128 months). Survivorship of the augments at 10 years was 92.2% (95% CI: 97.0–80.5%). In one case the augment was revised for infection and in 3 for loosening. In 1 of the revised cases there was a pre-operative pelvic discontinuity, the other 2 discontinuities in the series were not revised and remain asymptomatic. Conclusions. The results of the acetabular trabecular metal augments continue to be encouraging in the medium to long term with low rates of revision or loosening in this complex group of patients

Revision hip arthroplasty requires a comprehensive appreciation of abnormal bony anatomy. Advances in radiology and manufacturing technology have made three-dimensional representation of actual osseous anatomy obtainable. These models provide a visual and tactile reproduction of the bony abnormality in question. Life size three dimensional models were manufactured from CT scans of two patients. The first had multiple previous hip arthroplasties and bilateral hip infections. There was a pelvic discontinuity on the right and a severe postero-superior deficiency on the left. The second patient had a first stage revision for infection and recurrent dislocations. Specific metal reduction protocols were used to reduce artefact. The dicom images were imported into Mimics, medical imaging processing software. The models were manufactured using the rapid prototyping process, Selective Laser Sintering (SLS). The models allowed accurate templating using the actual prosthesis templates prior to surgery. Acetabular cup size, augment and buttress sizes, as well as cage dimensions were selected, adjusted and re-sterilised in advance. This reduced operative time, blood loss and improved surgical decision making. Screw trajectory simulation was also carried out on the models, thus reducing the chance of neurovascular injury. With 3D printing technology, complex pelvic deformities can be better evaluated and can be treated with improved precision. The life size models allow accurate surgical simulation, thus improving anatomical appreciation and pre-operative planning. The accuracy and cost-effectiveness of the technique were impressive and its use should prove invaluable as a tool to aid clinical practice

The presentations to be discussed by the panel are: 1.) No Increased Risk of Knee Arthroplasty Failure in Metal Hypersensitive Patients: A Matched Cohort Study; 2.) Knee Arthrodesis is Most Likely to Control Infection and Preserve Function Following Failed 2 Stage Procedure for Treatment of Infected TKA: A Decision Tree Analysis; 3.) Does Malnutrition Correlate with Septic Failure of Hip and Knee Arthroplasties?; 4.) Diagnosing Periprosthetic Joint Infection: The Era of the Biomarker Has Arrived; 5.) Are Patient Reported Allergies a Risk Factor for Poor Outcomes in Total Hip and Knee Arthroplasty?; 6.) Revising an HTO or UKA to TKA: Is it more like a Primary TKA or a Revision TKA?; 7.) At 5 Years Highly-Porous-Metal Tibial Components Were Durable and Reliable: A Randomised Clinical Trial of 389 Patients; 8.) Current Data Does Not Support Routine Use of Patient-Specific Instrumentation in Total Knee Arthroplasty; 9.) Barbed vs. Standard Sutures for Closure in Total Knee Arthroplasty: A Multicenter Prospective Randomised Trial; 10.) Particles from Vitamin-E-diffused HXL UHMWPE Induce Less Osteolysis Compared to Virgin HXL UHMWPE in a Murine Calvarial Bone Model; 11.) Construct Rigidity: Keystone for Reconstructing Pelvic Discontinuity; 12.) Do You Have to Remove a Corroded Femoral Stem?; 13.) Direct Anterior Versus Mini-Posterior Total Hip Arthroplasty with the Same Advanced Pain Management and Rapid Rehabilitation Protocol: Some Surprises in Early Outcome; 14.) Adverse Clinical Outcomes in a Primary Modular Neck/Stem System

Purpose. To assess acetabular component fixation by bone ongrowth onto a titanium plasma sprayed surface as used in revision total hip arthroplasty. Acetabular bone defects, a common finding in revision surgery, and their relation to outcome were also investigated. Methods. Clinical and radiological results were evaluated for all revision total hip replacements done between 2006 and 2011 that included the use of a specific revision acetabular component. Forty six hips in 46 patients were followed for an average of 2.5 years (range8 months to 6 years). The acetabular defects were graded according to Paprosky's classification. Results. Two cups needed re-revision for aseptic loosening with a rate of repeat revision of 4% (2 of 46). Only one other (unrevised) cup showed radiographic signs of loosening at the last follow up. Acetabular defects were found to be Paprosky type I in 9, type IIA in 10, type IIB in 9, type IIC in 12, Type IIIA in 2 and type IIIB in 3. Screw fixation was necessary in 72% (33 of 46) to achieve intraoperative stability. Conclusion. This study demonstrated that bone ongrowth onto a titanium plasma sprayed surface can achieve stable fixation in acetabular revision in the presence of contained bone defects. Short to medium term follow-up shows satisfying results. It should however be used with caution where the area of contact with host bone is limited as found in Paprosky type IIIA, IIIB types and pelvic discontinuity. NO DISCLOSURES

Aims

Dislocation remains a leading cause of failure following revision total hip arthroplasty (THA). While dual-mobility (DM) bearings have been shown to mitigate this risk, options are limited when retaining or implanting an uncemented shell without modular DM options. In these circumstances, a monoblock DM cup, designed for cementing, can be cemented into an uncemented acetabular shell. The goal of this study was to describe the implant survival, complications, and radiological outcomes of this construct.

Introduction. We present our experience of the coned hemi-pelvis (‘ice-cream’ cone) implant, using an extended posterior approach to the hip joint, in the management of pelvic bone loss and pelvic discontinuity. Methods. Retrospective study conducted utilising a prospectively collected database. Patients who underwent an ice-cream cone reconstruction between August 2004 – September 2011 were identified. All had a posterior approach to the hip. Femur prepared in the standard fashion. A variety of femoral components used. Demographic data was recorded along with the indication for surgery and outcomes. Results. 16 patients identified. Mean age was 62.2 years. 5 (31.25%) male. 11 (69.75%) female. Indications included; multiple hip revision surgery 4(25%); post Gridlestones for severe hip dysplasia 1 (6.25%); peri-acetabular metastatic deposits 11 (68.75%) from breast, renal, endometrial, prostatic, myeloma primary malignancies. Mean follow-up was 32.06 months. Complications; 1 intra-operative death from tumour embolus; 1 dislocation; 1 superficial surgical site infection. 3 deaths from their primary malignancy. Mean time from prosthesis implantation to death was 14.5 months. All patients at last follow-up were mobilizing. No implant has needed to be revised. Discussion. Pelvic bone loss provides reconstructive challenges. The coned hemi-pelvis is simple to make, easy and versatile to use even when there is little pelvis remaining. It provides a method of negotiating hip reconstruction in patients with severe pelvic bone loss. Orthopaedic surgeons are familiar with the posterior approach to the hip. The ice-cream cone implant can therefore be placed with ease using this well-known approach to the hip

Introduction. Failure of acetabular components has been reported to lead to large bone defects, which determine outcome and management after revision total hip arthroplasty (THA). Although Kerboull-type (KT) plate (KYOCERA Medical Corporation, Kyoto, Japan) has been used for compensating large bone loss, few studies have identified the critical risk factors for failure of revision THA using a KT plate. Therefore, the aim of this study is to evaluate the relationship between survival rates for radiological loosening and the results according to bone defect or type of graft. Patients and methods. This study included patients underwent revision THA for aseptic loosening using cemented acetabular components with a KT plate between 2000 and 2012. Bone defects were filled with beta Tricalcium phosphate (TCP) granules between 2000 and 2003 and with Hydroxyapatite (HA) block between 2003 and 2009. Since 2009, we have used femoral head balk allografts. Hip function was evaluated by using the Japanese Orthopaedic Association (JOA) score and University of California, Los Angeles (UCLA) activity. Acetabular defects were classified according to the American Academy of Orthopedic Surgeons (AAOS) classification. The postoperative and final follow-up radiographs were compared to assess migration of the implant. Kaplan–Meier method for cumulative probabilities of radiographic failure rate, and the comparison of survivorship curves for various subgroups using the log-rank test were also evaluated. Logistic regression was performed to examine the association of such clinical factors as the age at the time of operation, body mass index, JOA score, UCLA activity score, and AAOS classification with radiographic failure. Odds ratios (ORs) and 95% CIs were calculated. Multivariate analysis was performed to adjust for potential confounders by clinical factors. Values of p < 0.05 were considered significant. Results. The patient background is shown in Table 1. The JOA score at the final follow-up increased significantly (p < 0.001). Radiographic failure was evaluated for revision THA with beta-TCP, HA, and bulk allografts. These survival rates are shown in Table 2 and the rate in the AAOS type IV group was significantly lower than that in the type III group (p = 0.033). The survival curves were significantly different between beta -TCP group and bulk allograft group (p = 0.036) (Table 3). Multivariate analysis showed that AAOS type IV defect was found to be a risk factor for radiographic failure (radiographic failure: OR: 15.5, 95% CI: 1.4–175.4, p = 0.032). Discussion. Our results of survival rate are similar to those reported by previous studies. However, by comparing the survival rates between beta-TCP group and bulk allograft group, beta-TCP is not suitable for bone graft reconstruction of acetabular bone defects with a KT plate. We also found that AAOS type IV to be a risk factor for failure of revision THA. Therefore, bone defect size is the critical risk factor for failure of revision THA using a KT plate. New devices and techniques for KT plates are needed to improve the treatment of pelvic discontinuity

Introduction: today there is still no consense in reconstruction of severe acetabular defects in hip revision. Since 1988 we use size matched impacted acetabulum allografts. We evaluate how they behave in the mid–and longterm. Materials and Methods: we present our first 44 transplants with a mean follow-up of 12,2 years (range 7 to 18). The mean age of the patients was 58,6 years (range 19 to 83). According to Gross Classification 26 cases presented an acetabular defect type III while 18 presented type IV. Evaluation included Merle D’Aubigne Score and radiological assessment of allograft and cup according to Engh Criteria (JBJS, 1994). Results: homogenization of the radiological trabecular pattern was observed in 42 from 44 cases (95,4%). There were 3 infections and 7 cases of aseptic loosening (15,9%), that were revised with new cup implantation. Up to now none of these 7 cases have shown further signs of loosening. According to the Kaplan-Meier’s curves the overall predictive survival rate was 76.4% at 15 years. In cases of pelvic discontinuity (type IV) survivorship was significantly higher (85,7%, p=0,018). There was a highly marked improvement in Merle D’Aubigne Score in Gait (2,2 preoperative – 4,9 at follow-up, p=0,021) and Pain (2,5 preoperative – 5,4 at follow-up, p=0,032). Conclusions: despite published reports with high incidence of failures in the midterm with structural allografts this serie shows clearly that a size matched impacted acetabulum allograft can be successfull in severe defficiencies if proper donor selection and excellent fixation technique is undertaken

Introduction: today there is still no consense in reconstruction of severe acetabular defects in hip revision. Since 1988 we use size matched impacted acetabulum allografts. We evaluate how they behave in the mid- and longterm. Material and method: we present our first 44 transplants with a mean follow-up of 11,2 years (range 6 to 17). The mean age of the patients was 58,6 years (range 19 to 83). According to Gross Classification 26 cases presented an acetabular defect type III while 18 presented type IV. Evaluation included Merle D’Aubigne Score and radiological assessment of allograft and cup according to Engh Criteria (JBJS, 1994). Results: homogenization of the radiological trabecular pattern was observed in 42 from 44 cases (95,4 %). There were 3 infections and 7 cases of aseptic loosening (15,9 %), that were revised with new cup implantation. Up to now none of these 7 cases have shown further signs of loosening. According to the Kaplan-Meier’s curves the overall predictive survival rate was 76.4 % at 15 years. In cases of pelvic discontinuity (type IV) survivorship was significantly higher (85,7%, p=0,018). There was a highly marked improvement in Merle D’Aubigne Score in Gait (2,2 preoperative – 4,9 at follow-up, p=0,021) and Pain (2,5 preoperative 5,4 at follow-up, p=0,032). Conclusions: despite published reports with high incidence of failures in the midterm with structural allografts this serie shows clearly that a size matched impacted acetabulum allograft can be successfull in severe defficiencies if proper donor selection and excellent fixation technique is undertaken

Introduction. Acetabular revision surgery is becoming more prevalent with an estimated increase of 137% by 2030. It is challenging surgery especially in the presence of deficient bone loss. Several techniques of acetabular reconstruction are used world-wide. The greater the bone loss (Paprosky Type IIIA and IIIB, and AAOS Classification of Acetabular Bone Loss Type 3 and 4) the more complex are the reconstruction methods. There is however, insufficient literature comparing the contemporary techniques of revision acetabular reconstruction and their outcomes. Objectives. The purpose of this study was to systematically review the literature and to report clinical outcomes and survival of contemporary acetabular revision arthroplasty techniques (tantalum metal (TM) systems, uncemented revision jumbo cups, reinforced devices such as cages and rings, oblong cups and custom-made triflange cups). We specifically looked at outcomes when reconstruction was undertaken in the presence of bone loss. Methods. Full-text papers and those with an abstract in English published from January 2001 to October 2015, identified through international databases, Medline (PubMED), EMBASE, CINHAL, Web of Science, Cochrane and Google scholar databases, were reviewed. Studies reporting failure and complications following the use of tantalum metal systems, uncemented revision jumbo cups, reinforced devices as cages and rings, oblong cups and custom-made triflange cups, were included. Functional and radiological outcomes were also evaluated. Results. A total of 50 papers of level IV scientific evidence, comprising 2811 hips in total, fulfilled the inclusion criteria and were included. 1021 hips (291 of them classified Paprosky Type 3A, 98 3B and 14 AAOS type 3 and 2 type 4) with a mean follow-up 48.9 months, used TM cups with a mean overall re-revisions rate of 7.3%. 831 hips (156 of them classified Paprosky Type 3A, 178 3B and 228 AAOS type 3 and 43 type 4) with a mean follow-up 87.5 months, were reconstructed using cages and rings devices; these had a mean re-operation rate of 11.0%. 203 hips (44 of them classified Paprosky Type 3A and 8 3B) with a mean follow-up 90.9 months, were reconstructed using oblong cups and were associated with a mean of re-operate rate of 5.9%. In 518 hips (86 of them classified Paprosky Type 3A, 29 3B and 114 AAOS type 3 and 2 type 4) with a mean follow-up 117.4 months, jumbo cups were implanted and revision rate was 12.1%. Custom-made triflange cups were used in 238 hips (3 of them classified Paprosky Type 3A, 64 3B and 42 AAOS type 3 and 139 type 4) with a mean follow-up 57.9 months, and they were re-roperated in 16.8% of cases. Overall patients had improved post-operative hip scores for each different procedure. We have observed that oblong cups components had a lower failure rate compared with other different materials considered in this review. Custom-made triflange cups had one of higher failure rate, however they had been used in the most complex cases. It is possible that other designs had more favourable outcomes having been used in less demanding patients. Conclusions. This review confirms successful acetabular reconstructions using several techniques and highlights key features and outcomes of different techniques. In particular oblong and TM cups have proven long-term survivorship and our results strongly suggest these devices as preferable choice especially in moderate to high-grade acetabular defects. For hip revisions following the development of pelvic discontinuity custom-made triflange cups have a main role, however the results are not always favourable

Aims: The purpose of this study is to evaluate clinic and radiological results in acetabular revision using hemispherical hydroxyapatite (HA)-coated cups and morselized allograft in the presence of sever bone defects (Paprosky type IIIA). Methods: From a serie of 218 patients having revision total hip arthroplasty between1995 and 1999, 42 hips in 42 patients were included in this retrospective study. The inclusion criteria were:. Ð Presence of sever bone loss without pelvic discontinuity (Paprosky type IIIA). Ð Use of hemispherical HA-coated acetabular component inserted without cement. Ð Aseptic loosening as cause of revision. All revisions were carried out by the same surgical team using a posterolateral approach. Morselized allograft was used in all cases. The mean age at the time of revision surgery was 70 years (range, 48 to 84). The mean follow-up was 52 months (range, 36 to 81). In 39% of the cases a extra large cup (more than 60 mm) was used. Results: the average Merle dñAubignŽ score rose from 7.3 points preoperatively to 17.2 points at follow-up (90% of the patients were pain free). All the cups remained radiologically stable at follow-up. Partial resorption of the allograft without jeopardising implant stability was detected in 4 cases (10%); all the rest showed radiological consolidation and remodelling of the medial wall of the acetabulum. Conclusions: these results strongly support the use of hemispherical HA-coated cups, combined with morselized allograft, in acetabular revision even in the presence of major acetabulum bone loss

Aims

To investigate the extent of bone development around the scaffold of custom triflange acetabular components (CTACs) over time.

Acetabular component loosening and pelvic osteolysis continue to be a significant clinical challenge in revision hip arthroplasty. We present results of 339 cases of acetabular reconstruction with impacted allograft. All patients who under went acetabular reconstruction with impaction allograft between July 1995 and July 1999 were included. Clinical and radiographic data was collected prospectively. There were 339 patients identified. Average age was 71 years. The majority were first time revisions (201) but the group includes 2nd, 3rd and 4th revisions with 34 two-stage revisions and 44 primary arthroplasties. There were multiple surgeons with 2/3 being consultants and 1/3 fellows. Pre and post-operative clinical assessment included Oxford and Harris hip scores, and a modified Charnley score for pain, function and range of movement. Pre-operative radiographs were classified with the Paprosky classification. Follow up radiographs were assessed for graft thickness, component migration, graft reabsorption and lucent lines. There were 10 grade I, 205 grade II, and 103 grade III defects with 3 pelvic discontinuities. Reconstruction methods included impaction only, rim and/or medial mesh, KP plate fixation and reinforcement cages. Follow up average was 6.1 years (4.3 – 8.4) and no patient was lost. Infection was identified in 13 patients (5 recurrent 89% eradication and 8 new 2.6%). There were 6 nerve injuries, 2 remain unresolved and 13 patients dislocated (3.8%). There have been 46 deaths in the group with 3 being peri-operative. There have been 18 re-operations for aseptic loosening. 7 KP plates fractured, 1 cage migrated and 10 rim meshes failed. Factors associated with aseptic loosening include use of a large rim mesh particularly with an allograft thickness of > 2cm. We conclude that impaction allografting is a reliable method for acetabular reconstruction. Careful consideration should be given when allograft thickness will be > 2cm and a large rim mesh is required

The number of joint revision surgeries is rising, and the complexity of the cases is increasing. In 58% of the revision cases, the acetabular component has to be revised. For these indications, literature decision schemes [Paprosky 2005] point at custom pre-shaped implants. Any standard device would prove either unfeasible during surgery or inadequate in the short term. Studies show that custom-made triflanged implants can be a durable solution with good clinical results. However, the number of cases reported is few confirming that the device is not in widespread use. Case Report. A patient, female 50 yrs old, diagnosed having a pseudotumor after Resurfacing Arthroplasty for osteo-arthritis of the left hip joint. The revision also failed after 1 y and she developed a pelvic discontinuity. X-ray and Ct scans were taken and sent to a specialized implant manufacturer [Mobelife, Leuven, Belgium]. The novel process of patient-specific implant design comprises three highly automated steps. In the first step, advanced 3D image processing presented the bony structures and implant components. Analysis showed that anterior column was missing, while the posterior column was degraded and fractured. The acetabular defect was diagnosed being Paprosky 3B. The former acetabular component migrated in posterolateral direction resulting in luxation of the joint. The reconstruction proposal showed the missing bone stock and anatomical joint location. In the second step, a triflanged custom acetabular metal backing implant was proposed. The bone defect (35ml) is filled with a patient-specific porous structure which is rigidly connected to a solid patient-specific plate. The proposed implant shape is determined taking into account surgical window and surrounding soft tissues. Cup orientation is anatomically analyzed for inclination and anteversion. A cemented liner fixation was preferred (Biomet Advantage 48mm). Screw positions and lengths are pre-operatively planned depending on bone quality, and transferred into surgery using jig guiding technology (Materialise NV, Leuven, Belgium). In the third step, the implant design was evaluated in a fully patient-specific manner in dedicated engineering (FEA) software. Using the novel automated CT-based methodology, patient-specific bone quality and thickness, as well as individualised muscle attachments and muscle and joint forces were included in the evaluation. Implants and jig were produced with Additive Manufacturing techniques under ISO 13485 certification, using respectively Selective Laser Melting (SLM) techniques [Kruth 2005] in medical grade Ti6Al4V material, and the Selective Laser Sintering technique using medical grade epoxy monomer. The parts were cleaned ultrasonically, and quality control was performed by optical scanning [Atos2 scanning device, GOM Intl. AG, Wilden, Switzerland]. Sterilization is performed in the hospital. CONCLUSION. A unique combination of advanced 3D planning, patient-specific designed and evaluated implants and drill guides is presented. This paper illustrates, by means of a clinical case, the novel tools and devices that are able to turn reconstruction of complex acetabular deficiencies into a reliable procedure

Introduction and Aims: Resection of large pelvic bone tumors often results in segmental defects with pelvic discontinuity and loss of the acetabulum. We reviewed the functional and oncologic outcomes following pelvic allograft and total hip arthroplasty (THA) reconstruction. Method: A retrospective review of our prospectively collected database was undertaken. Minimum follow-up was 15 months (range 15–167 months). Nineteen patients were hemipelvic resections (12 Type I+II and seven Type I+II+III, 11 of these cases included partial sacral resection) reconstructed by hemipelvic allograft and THA. In comparison, five patients had Type II acetabular resections, reconstructed with structural allograft, roof ring and THA. Functional outcome was assessed by the Toronto Extremity Salvage score (TESS) and the Musculoskeletal Tumor Society scores (MSTS87 and MSTS93). Results: Osteosarcoma and chondrosarcoma were the most frequent tumors. All patients required walking aids. In the hemipelvic group there were two early deaths (peri-operative haemorrhage and aplastic anaemia). In seven patients (37%), the allograft remained intact without infection but three required revision THA for component loosening. For these seven patients, the functional outcome scores were TESS 64%, MSTS87 17/35 and MSTS93 45% (mean follow-up 52 months). There were nine cases of deep infection (47%) with three patients maintaining a functional implant with antibiotic suppression. Of the remaining six patients with infection, four patients required hindquarter amputation, one patient required allograft removal and the allograft fragmented in the remaining patient. The 19th patient was revised following allograft fracture. Five patients sustained at least one allograft fracture. In the Type II acetabular group, three patients had no complications, and two patients sustained dislocations. The average scores were TESS 78%, MSTS87 21/35 and MSTS93 64% (mean follow-up 55 months). Conclusion: Reconstruction of large pelvic defects including the acetabulum using hemipelvic allograft and THA is associated with high complication rates, however when successful provides reasonable function. In comparison, the functional outcome after allograft and THA reconstruction of isolated Type II acetabular resections was better and more predictable

A retrospective review of our prospectively collected database was undertaken to determine the functional and oncologic outcome following combined pelvic allograft and total hip arthroplasty (THA) reconstruction of large pelvic bone defects following tumour resection. There were twenty-four patients with a minimum followup of fifteen months. The complication rate following hemipel-vic allograft and THA reconstruction of resection Types I+II and I+II+III was high, but when successful this reconstruction resulted in reasonable functional outcome. In comparison, the functional outcome after allograft and THA reconstruction of isolated Type II acetabular resections was better and more predictable. Resection of large pelvic bone tumours often results in segmental defects with pelvic discontinuity and loss of the acetabulum. We reviewed the functional and oncologic outcomes following pelvic allograft and total hip arthroplasty (THA) reconstruction. Reconstruction of large pelvic defects including the acetabulum using hemipelvic allograft and THA is associated with high complication rates, however when successful provides reasonable function. In comparison, the outcomes of allograft and THA for acetabular defects alone are better and more predictable. A retrospective review of our prospectively collected database was undertaken. Minimum followup was fifteen months (15–167). Nineteen patients were hemipel-vic resections (twelve Type I+II and seven Type I+II+III, eleven cases including partial sacral resection) reconstructed by hemipelvic allograft and THA. Five patients had Type II acetabular resections, reconstructed with structural allograft, roof ring and THA. Osteosarcoma and chondrosarcoma were the most frequent tumours. All patients required walking aids. In the hemipelvic group there were two early deaths (peri-operative haemorrhage and aplastic anaemia). In seven patients (37%) the allograft remained intact without infection but three required revision THA for loosening. For these seven patients the functional outcome scores were TESS 64%, MSTS87 17/35 and MSTS93 of 45% (mean fifty-two months.). There were nine cases of deep infection (47%) with three patients maintaining a functional implant. The nineteenth patient was revised following allograft fracture. In the Type II acetabular group, three patients had no complications, and two patients dislocated. The average scores were TESS 78%, MSTS87 21/35 and MSTS93 64% (mean fifty-five months)

The principles of acetabular reconstruction include the creation of a stable acetabular bed, secure prosthetic fixation with freedom of orientation, bony reconstitution, and the restoration of a normal hip centre of rotation with acceptable biomechanics. Acetabular impaction grafting, particularly with cemented implants, has been shown to be a reliable means of acetabular revision. Whilst our practice is heavily weighted towards cementless revision of the acetabulum with impaction grafting, there is a large body of evidence from Tom Slooff and his successors that cemented revision with impaction grafting undertaken with strict attention to technical detail is associated with excellent long terms results in all ages and across a number of underlying pathologies including dysplasia and rheumatoid arthritis. We use revision to a cementless hemispherical porous-coated acetabular cup for most isolated cavitary or segmental defects and for many combined deficiencies. Morsellised allograft is packed in using chips of varied size and a combination of impaction and reverse reaming is used in order to create a hemisphere. There is increasing evidence for the use of synthetic grafts, usually mixed with allograft, in this setting. The reconstruction relies on the ability to achieve biological fixation of the component to the underlying host bone. This requires intimate host bone contact, and rigid implant stability. It is important to achieve host bone contact in a least part of the dome and posterior column – when this is possible, and particularly when there is a good rim fit, we have not found it absolutely necessary to have contact with host bone over 50% of the surface. Once the decision to attempt a cementless reconstruction is made, hemispherical reamers are used to prepare the acetabular cavity. Sequentially larger reamers are used until there is three-point contact with the ilium, ischium and pubis. Acetabular reaming should be performed in the desired orientation of the final implant, with approximately 200 of anteversion and 400 of abduction (or lateral opening). Removing residual posterior column bone should be avoided. Reaming to bleeding bone is desirable. Morsellised allograft is inserted and packed and/or reverse reamed into any cavitary defects. This method can also be applied to medial wall uncontained defects by placing the graft onto the medial membrane or obturator internus muscle, and gently packing it down before inserting the cementless acetabular component. Either the reamer heads or trial cups can be used to trial prior to choosing and inserting the definitive implant. The fixation is augmented with screws in all cases. Incorporation of the graft may be helped by the use of autologous bone marrow. Cementless acetabular components with impaction grafting should not be used when the host biology does not allow for stability or for bone ingrowth. This includes the severely osteopenic pelvis, pelvic osteonecrosis after irradiation, tumours, and metabolic bone disorders. They should also not be used in the presence of pelvic discontinuity unless the structure of the pelvic ring has been restored with a plate, or specialised materials/porous metals are used. The challenge of reconstituting the acetabulum depends on the degree and type of bone loss. The principles of maximising host bone-implant contact and implant stability have borne fruit in our experience with cementless revision. The advantages of bone grafting in acetabular reconstruction include the ability to restore bone stock, to rebuild a normal hip center and hip biomechanics and to increase bone stock for future revisions

Aims

Large bone defects resulting from osteolysis, fractures, osteomyelitis, or metastases pose significant challenges in acetabular reconstruction for total hip arthroplasty. This study aimed to evaluate the survival and radiological outcomes of an acetabular reconstruction technique in patients at high risk of reconstruction failure (i.e. periprosthetic joint infection (PJI), poor bone stock, immunosuppressed patients), referred to as Hip Reconstruction In Situ with Screws and Cement (HiRISC). This involves a polyethylene liner embedded in cement-filled bone defects reinforced with screws and/or plates for enhanced fixation.

Introduction: One of the greatest challenges in the actual Orthopaedic Surgery is how to reconstruct with a certain long-therm efþcacy the severe acetabular defects in hip revision. AWholeAcetabularAllograft represents a human tissue of good quality, (donor age under 40 years), that keeps the original trabecular stucture with a 100% adaptation to host bone. Material & method: We perform acetabular reconstructions according to our own so called ÒICATME Classiþcation of Acetabular Defects: Type I: Cavitary Defects. Cup. Type II: Simple columnar Defect. Type III: Complexe Columnar Defect. Type IV: Pelvic Discontinuity. From 1988 up to January 2001 we have performed 44 acetabular reconstructions with whole acetabulum allografts. Follow up ranging from 2 to 12 years (Mean: 7,2 years). Mean patient age: 58,6 years. Evaluation includes clinical examination (Merle DñAubigne Score for Gait and Pain) and radiological measurements according to the Engh Criteria (Engh-Massin-Southers, JBJS, 1994) Results: Radiological consolidation was achieved in 33 from the 35 cases (94,2%). There were 3 infections during the þrst year. One infection was solved by a 1 stage THA replacement with antibiotic-loaded cement (Endoklinik, Hamburg; the allograft was refreshed and mantained) and 2 by Girldestone procedure. In 7 cases (20%) there was a marked bone resorption with loosening of the acetabular component and screws ruptures. From these 7 cases 4 occurred 5 years after reconstruction. In all these cases the allograft was consolidated and it only needed to be refreshed before to insert into it a new cemented acetabular cup. No more acetabular reconstruction was necessary. According to the Kaplan-Meierñs Curves the predictive survival rate is 72% at 10 years, while it is 87,5% at 5 years and 78,2 at 8 years. There is a highly marked improvement in Merle DñAubigne Score. Gait paramether: 2,2 preoperative Ð 5,4 at follow-up. Pain paramether: 2,5 preoperative Ð 4,9 at follow-up. Conclusions: Whole Acetabulum Allograft have an excellent bone quality, intact and identical trabeculation, 100% adaptability. Survival Rate of 72% at 10 years with the added advantatge that all failured cases could be solved without any further acetabular reconstruction. these patients to keep a good clinical-functional score.•. We have obtained a very good result in pelvis discontinuities. We think this is a method to consider it as highly efþcient for these cases

Aims

The use of a porous metal shell supported by two augments with the ‘footing’ technique is one solution to manage Paprosky IIIB acetabular defects in revision total hip arthroplasty. The aim of this study was to assess the medium-term implant survival and radiological and clinical outcomes of this technique.

Aims

The burden of revision total hip arthroplasty (rTHA) continues to grow. The surgery is complex and associated with significant costs. Regional rTHA networks have been proposed to improve outcomes and to reduce re-revisions, and therefore costs. The aim of this study was to accurately quantify the cost and reimbursement for a rTHA service, and to assess the financial impact of case complexity at a tertiary referral centre within the NHS.

Aims

The aim of this study was to examine the implant accuracy of custom-made partial pelvis replacements (PPRs) in revision total hip arthroplasty (rTHA). Custom-made implants offer an option to achieve a reconstruction in cases with severe acetabular bone loss. By analyzing implant deviation in CT and radiograph imaging and correlating early clinical complications, we aimed to optimize the usage of custom-made implants.