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

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

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. 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

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

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

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

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

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

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

Chronic pelvic discontinuity (CPD) during revision hip arthroplasty is a challenging entity to address. The aim of this study was to evaluate the clinical and radiologic outcomes, and complications of the “acetabular distraction technique” for the management of CPD during revision hip arthroplasty. Patients with CPD, who underwent acetabular revision between 2014 and 2022 at two tertiary care centres, using an identical distraction technique, were evaluated. Demographic parameters, pre-operative acetabular bone loss, duration of follow-up, clinical and radiologic outcomes, and survivorship were evaluated. In all, 46 patients with a mean follow-up of 34.4 (SD=19.6, range: 24–120) months were available for evaluation. There were 25 (54.3%) male, and 21 (45.7%) female patients, with a mean age of 58.1 (SD=10.5, range: 40–81) years at the time of revision surgery. Based on the Paprosky classification of acetabular bone loss, 19 (41.3%), 12 (26.1%), and 15 (32.6%) patients had type 3b, 3a, and 2c defects. All patients were managed using the Trabecular Metal™ Acetabular Revision System; 16 patients required additional Trabecular Metal™ augments. The mean HHS improved from 50.1 (SD=7.6, range: 34.3 – 59.8) pre-operatively, to 86.6 (SD=4.2, range: 74.8 -91.8) at the last follow-up. Two patients (4.3 %) developed partial sciatic nerve palsy, two (4.3%) had posterior dislocation, and one (2.2%) required re-revision for aseptic loosening. Radiologically, 36 (78.3%) patients showed healing of the pelvic discontinuity. The Kaplan-Meier construct survivorship was 97.78% when using re-revision for aseptic acetabular loosening as an endpoint. The acetabular distraction technique has good clinical and radiologic outcomes in the management of CPD during revision hip arthroplasty

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

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

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

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

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

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

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

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