In patients with severe acetabular deficiency due to rheumatic arthritis (RA), the mid-term result of THA including a bone graft in the acetabular bed were analyzed. A total of 32 patients with 40 joints, comprising of 30 females and 2 males, were reviewed in this study. These patients had severe acetabular deficiency and were receiving THA for RA, including a bone graft in the acetabular bed. The average age at surgery was 58. 3 years and the average follow-up period was 6. 2 years. These patients had suffered from RA for 21 years on an average. The acetabular bed was filled with the chip bone and covered with the slice bone, followed by strong pressurization of the implanted bone and fixation of the cup with a screw. The patients were evaluated clinically using the Harris hip score, and radiologically using the Gruen radiographic analysis and the Sotelo-Garza and Charnley classification. In the clinical evaluation using score, the mean score improved from 39. 7 preoperatively to 82. 3 postoperatively. An improvement in pain, walking ability, ROM and ADL were observed. In the radiological evaluation using the Gruen analysis, more radiolucent lines tended to appear in the zone 1, of which none was progressive or indicated loosening. On the femoral side, more partially radiolucent lines of 1 mm or less tended to appear in the zone 4, of which none indicated osteolysis or loosening. The mean thickness of acetabular bed improved from 4. 3 mm preoperatively to 13. 5 mm postoperatively. During the follow-up period, no collapse of the implanted bone, dislocation of the cup or loosening was observed. Treatment with the bone graft method using slice bone and chip bone are used for acetabular deficiency in rheumatic hip joint in our department, this methods is considered to be an effective treatment, because it has provided a good initial fixation of cup and a good graft survival

Revision hip arthroplasty for severe acetabular deficiency is a technically challenging operation. Many different methods have been described for the management of acetabular deficiency. These include augmentation with bone cement, structural allografts, impaction grafting, support rings with graft and reconstruction with a high centre of rotation. The long term results of many of these methods were variable. We reviewed the outcome of a stemmed acetabular cup (McMinn cup, Link UK) used with morsellised bone graft for revision hip arthroplasty with severe acetabular deficiency. The implant was used only in the most severe cases of acetabular deficiency where it was impossible to achieve stable fixation using simpler methods. This device was used in only 13 out of 265 revision arthroplasties performed by the senior author. Between 1995 and 2002 13 acetabulae were reconstructed using a stemmed acetabular cup and non-structural morsellised bone graft. All were revision procedures with the number of previous operations on the same hip ranging between 1 and 4. 2 patients died from causes not related to surgery. 1 hip was revised for persistent discharge although no organisms were identified on repeated cultures. The mean follow-up of the remaining 10 hips was 72 months (range 46 – 108 months). All patients were satisfied with the results and their function improved significantly post-operatively. 8 of the 10 people report no pain from the hip and 2 reported slight or occasional pain which did not interfere with their activities at last follow-up. The mean Harris Hip Score was 84.6 (range 70 to 99.8). Radiological assessment showed regeneration of acetabular bone stock. Some X-Rays showed proximal migration of the cup but with no evidence of loosening at last follow-up. Acetabular reconstruction using the McMinn stemmed acetabular cup is a useful technique in revision hip arthroplasty with severe acetabular deficiency

The cranial cup is now a standardised implant in acetabular revision surgery. In order to illustrate the positive results of a standardised implant in acetabular revision surgery in comparison to other possibilities of reconstruction, we analysed results of all data in our study group. Aseptic loosening of implants often causes segmental and cavitary acetabular deficiency. Experiences gained in radical tumour surgery with reconstruction by custommade endoprostheses induced the development of the cranial cup for revision total hip arthroplasty. This new cementless revision cup has an oval shape and a special cranial flap, as well as an intramedullary rod if necessary. This type of cranial cup has been used since 1993. From 9/97 to 1/99, we implanted 30 cranial cups in revision hip surgery and collected all data of these patients prospectively. Clinical and x-ray follow-up was documented on a regular basis. Acetabular deficiency occurred twice in type 1, five times in type 2, twenty-two times in type 3 and once in type 4. The AAOS D’Antonio score was used. Cranial cups were implanted without cranial flap in 10 cases, with cranial flap in 20 cases and once using the intramedullary rod additionally. Only 28 patients were included in our last examination because one patient had died and one was bedridden because of a reason other than the hip. The Harris hip score increased from an average of 32 points preoperatively to 63 points postoperatively. Twenty-one patients are satisfied or very satisfied with their surgery. Radiograph examinations showed an average inclination angle of 42.5° in all cranial cups. Up to now there have been complications in four patients who suffered luxations, but only one required a change of inlay. One intraoperative injury of the urinary bladder had to be revised later. Three implants showed a change of position in x-ray. One was the patient with the urinary bladder injury and possible septic loosening, the second was a patient with extreme osteoporosis, and the third was a patient who did not receive an intramedullary rod for a type 4 lesions. Currently, these three patients do not have any complaints. We have always achieved primary stability. Morselised bone autografts or bone substitute materials were used to fill remaining defects. An intramedullary rod should be used in pelvis discontinuity and is obligatory to achieve the necessary stability. Developed from the experiences of custom-made tumour endoprostheses, the cranial cup with all possible variations is an appropriate intraoperative variable implant in revision acetabular surgery

We evaluated the use of bilobed acetabular components in the treatment of acetabular deficiency during revision and complex primary total hip replacements. 79 patients (83 hips) were operated upon between august 1990 and December 2005 64 patients were reviewed clinically and radiologically.7 patients had died from unrelated causes. 3 patients were followed up clinically and radiologically for one year and were doing well at their last appointments. 5 were lost in follow up. The mean follow up of patients was 5.5 year (range, 2–15 years). One patient was revised for aseptic loosening. The average post operative Harris hip score was 94.9 (range 74–100) at the last follow up appointments of 68 patients. Two patients developed deep wound infection and one patient dislocated three months post operatively, treated with a constrained liner. At the latest follow up the cumulative survival rate for aseptic loosening with revision being the end point is 97% at 15 years. These results support the use of bilobed of-the-shelf cups in the reconstruction of acetabular defects with intact anterior and posterior columns

Introduction. Different classification systems for acetabular deficiencies, including AAOS and Paprosky, are commonly used. Classification of these bone defects is often performed based on Xrays or CT images. Although the amount of bone loss is rarely measured quantitatively in these images, objective and quantitative data on the degree of bone loss could facilitate correct and consistent classification. Recently, a computerized CT-based tool was presented to quantitatively asses bone loss: TrABL (Total radial Acetabular Bone Loss). This study demonstrates on an extended patient population that TrABL combined with standard classification systems provides more detailed, quantitative information on bone defects. Methods. CT scans of 30 severe acetabular defects, classified Paprosky IIIA and IIIB, were collected and analysed with TrABL. The tool automatically calculated the total amount of bone that was missing around the acetabulum, seen from the hip's original rotation centre. Six anatomical regions were defined for which the degree of bone loss was expressed: anterosuperior, anteroinferior, inferior, posteroinferior, posterosuperior and medial. Results. Statistical analysis highlighted that total bone loss was highest in the posterosuperior region (63%±27%). Bone loss was lowest inferiorly. No statistical differences were found between the anterosuperior, anteroinferior, posteroinferior, and medial regions. The majority of the defects suffered at least 25% bone loss in more than half of the regions. All defects had at least one region with the same degree of bone loss. The quantitative 3D data of TrABL provided more information compared to general classification schemes. This information has shown to be crucial during implant selection and preoperative planning for multiple clinical cases. Conclusion. Classification of acetabular bone deficiencies into existing systems can be refined by the quantitative data provided by TrABL. As a result, the ease and consistency regarding the treatment selection for particular categories of challenging defects will increase

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.

Introduction: The objectives of this study were to evaluate acetabular bone deficiency in revision THA with a simple classification on the anteroposterior pelvis radiograph and correlate the results of cementless hemispherical porous coated cup and cancellous bone graft reconstruction. Methods: 70 acetabular revisions reconstructed employing large ‘jumbo’ porous coated cups with cancellous allo-grafting were evaluated at a mean follow-up of 5 years (range 2 – 10 years). During this time period 7 additional acetabular reconstructions required impaction grafting, cage reinforcement and cemented cups. Pre- and postoperative measurements of acetabular bone loss and the position of the revision component were performed with respect to a previously described triangle defining the placement and size of an idealcup. Impaction bone allo-grafting techniques were employed to fill defects. A minimum of 40% implant contact to host bone, especially in the weight-bearing dome region was attained in all cases and a minimum of 2 screws supplemented fixation to the ilium. Clinical evaluation comprised the HSS score and a patient assessment questionnaire (PAQ). Radiographically, cups were examined for filling of defects, ingrowth, graft consolidation, and stability. Results: The mean HSS score improved from 18 to 33 out of a maximum of 40. The mean superior bone defect was 18 mm (range 10 – 25mm) and the mean medial bone defect was 7 mm (range 0 – 22mm). All the cement-less acetabular components were bone ingrown with the exception of one stable fibrous union. Allograft incorporation occurred at a mean of 7 months after surgery. Neither the status of Kohler’s line nor the Paprosky class correlated with eventual radiographic or clinical results. Discussion: We present a simple method of evaluation of acetabular bone deficiency on the A-P pelvis radiograph employing a triangle that locates the ideal center of rotation of the hip. Superior bone loss upto 25 mm and medial migration as much as 22 mm has been successfully reconstructed employing impacted, cancellous allograft, large porous coated hemispherical Cementless acetabular components and screw fixation with excellent outcomes at intermediate-follow-up. Larger defects necessitate complex reinforced cage reconstruction

This study was to analyze the minimum ten years clinical and radiological results of revision total hip arthroplasties using allogenic impaction bone graft and cemented cup in acetabular bone deficiency. Fifty two revision total hip arthroplasties that had been performed in forty nine patients between March 1992 and June 1997 and had followed more than minimum ten years were included in this study. The clinical and radiological results were evaluated by Harris hip score and roentgenography including anterior-posterior view of pelvis and lateral view of operated hip. The mean Harris hip score was 47 points preoperatively, 81 points at three years, 84 points at seven years, and 82 points at ten years after revision. In radiological evaluation, osseous union between grafted bone and host bone was seen within four months in 47 hips, a complete grafted bone-cement radiolucent line of two millimeter or more in at least one zone was seen in 5 hips at two years, 7 hips at seven years, and 2 hip at 10 years follow-up. We recommend the technique using allogenic impaction bone graft and cemented cup to reconstruct the acetabular cavitary defect in revision total hip arthroplasties

Introduction: The increasing utilization of total hip arthroplasty and the increasing life expectancy have brought an increasing incidence of revision hip arthroplasty. With severe acetabular, revision surgery with the use of standard cemented or press-fitted components is inadequate for fixation. In these cases the use of proximal femoral allograft can restore the deficiency.

Purpose: To present a new technique and preliminary results of revision total hip arthroplasty using proximal femoral allograft prosthetic composites for massive ace-tabular bone loss. The technique uses the natural vector of forces in the intertrochanteric region in an opposite direction at the acetabular defect.

Methods: From June 2000 to July 2001, seven patients underwent reconstruction of massive acetabular defects with proximal femoral allograft bone. The etiologies for bone loss were infection in 2 patients, aseptic loosening in 4 and acetabular protrusion in 2 patients. In 4 hips there were also femoral defects that was reconstructed with allograft. The average age of the patients was 69.8 years. All patients were wheel chair bound prior to surgery. Harris Hip Score was used to assess preoperative and follow-up function level.

Results: Harris Hip Score improved significantly in all patients. All patients are ambulatory at follow-up. Complications included 2 dislocation and 2 deep-vein thrombosis. No allograft resorbtion was noted at follow-up.

Conclusions: The proximal femoral allograft provides a solid construct for the acetabular cup in large acetabular bone defects. Although failure and complication rates might be higher than revision procedures with lesser bone defects, this reconstructive option for massive ace-tabular defects dramatically improves a patient’s function level.

Reconstruction of an acetabulum following severe bone loss can be challenging. The aim of this study was to determine the outcome of acetabular reconstruction performed using trabecular metal shell for severe bone loss.

Between June 2003 and June 2006 a total of 29 patients with significant acetabular bone stock deficiency underwent revisions using trabacular metal shell. According to Paprosky classification, there were 18 patients with grade IIIA and 11 patients with grade IIIB defects. Nineteen patients required augments to supplement the defects. Functional clinical outcomes were measured by WOMAC and Oxford hip. Detailed radiological assessments were also made.

At most recent follow up (average 5.5 years, range 3.5–8.5) the mean Oxford hip score improved from 12 preoperatively to 27.11 postoperatively and WOMAC score from 17.57 preoperatively to 34.14 postoperatively The osseointegration was 83% according to Moore's classification. There were two reoperations; one was for instability, and one for aseptic loosening. One patient has a chronic infection and one had a periprosthetic fracture, both treated conservatively.

Despite challenges faced with severe preoperative acetabular defects the early results using this technique in Grade III A and B is encouraging.

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.

Traditional radiographic criteria might underestimate or fail to detect subtle types of acetabular dysplasia. Acetabular sector angles (ASA) can measure the degree of anterior and posterior coverage of the femoral head on computed tomography (CT). This study aims to determine ASA values at different axial levels in a cohort of (1) asymptomatic, high-functioning hips without underlying hip pathology (controls); and (2) symptomatic, dysplastic hips that underwent periacetabular osteotomy (PAO). Thereby, we aimed to define CT-based thresholds for hip dysplasia and its subtypes. This is an IRB approved cross-sectional study of 51 high functioning, asymptomatic patients (102 hips) (Oxford Hip Score >43), without signs of osteoarthritis (Tönnis grade≤1), who underwent a CT scan of the pelvis (mean age: 52.1±5.5 years; 52.9% females); and 66 patients (72 hips) with symptomatic hip dysplasia treated with peri-acetabular osteotomy (PAO) (mean age: 29.3±7.3 years; 85.9% females). Anterior and posterior acetabular sector angles (AASA & PASA) were measured by two observers at three CT axial levels to determine equatorial, intermediate, and proximal ASA. Inter- and intra-observer reliability coefficient was high (between 0.882–0.992). Cut-off values for acetabular deficiency were determined based on Receiver Operating Characteristic (ROC) curve analysis, area under the curve (AUC) was calculated. The dysplastic group had significantly smaller ASAs compared to the Control Group, AUC was the highest at the proximal and intermediate PASA. Controls had a mean proximal PASA of 162°±17°, with a cut-off value for dysplasia of 137° (AUC: 0.908). At the intermediate level, the mean PASA of controls was 117°±11°, with a cut-off value of 107° (AUC 0.904). Cut-off for anterior dysplasia was 133° for proximal AASA (AUC 0.859) and 57° for equatorial AASA (AUC 0.868). Cut-off for posterior dysplasia was 102° for intermediate PASA (AUC 0.933). Measurement of ASA on CT is a reliable tool to identify dysplastic hips with high diagnostic accuracy. Posterior ASA less than 137° at the proximal level, and 107° at the intermediate level should alert clinicians of the presence of dysplasia

Aim. Aim of this monocentric, prospective study was to evaluate the safety, efficacy, clinical and radiographical results at 24-month follow-up (N = 6 patients) undergoing hip revision surgery with severe acetabular bone defects (Paprosky 2C-3A-3B) using a combination of a novel phase-pure betatricalciumphosphate - collagen 3D matrix with allograft bone chips. Method. Prospective follow-up of 6 consecutive patients, who underwent revision surgery of the acetabular component in presence of massive bone defects between April 2018 and July 2019. Indications for revision included mechanical loosening in 4 cases and history of hip infection in 2 cases. Acetabular deficiencies were evaluated radiographically and CT and classified according to the Paprosky classification. Initial diagnosis of the patients included osteoarthritis (N = 4), a traumatic fracture and a congenital hip dislocation. 5 patients underwent first revision surgery, 1 patient underwent a second revision surgery. Results. All patients were followed-up radiographically with a mean of 25,8 months. No complications were observed direct postoperatively. HHS improved significantly from 23.9 preoperatively to 81.5 at the last follow-up. 5 patients achieved a defined good result, and one patient achieved a fair result. No periprosthetic joint infection, no dislocations, no deep vein thrombosis, no vessel damage, and no complaint about limbs length discrepancy could be observed. Postoperative dysmetria was found to be + 0.2cm (0cm/+1.0cm) compared to the preoperative dysmetria of − 2.4 cm (+0.3cm/−5.7cm). Conclusions. Although used in severe acetabular bone defects, the novel phase-pure betatricalciumphosphate - collagen 3D matrixshowed complete resorption and replacement by newly formed bone, leading to a full implant integration at 24 months follow-up and thus represents a promising method with excellent bone regeneration capacities for complex cases, where synthetic bone grafting material is used in addition to autografts

Introduction. Total hip arthroplasties in younger patients often requires revision because these patients frequently have acetabular deficiencies, which hamper proper implantation of the cup essential for good long-term prosthesis survival. For 30 years, we have used a biological acetabular-reconstruction technique with bone-impaction grafting in all patients <50 years with an acetabular deficiency at surgery, always in combination with a cemented total hip implant. Methods. We evaluated all 150 consecutive patients (177 hips) < 50 years with an acetabular reconstruction by bone-impaction grafting surgically-treated from 1978–2004 at our clinic. Mean follow-up was 10.3 (range, 2.0–28.3) years with no patient lost to follow-up. Mean index surgery age was 38.1 (range, 16–49) years. Clinical, radiological, and statistical analysis of all patients was performed. Results. Twenty-eight of 177 hips were revised at a mean of 10.5 years (range, 5 days to 23.2 years). Reasons for revision were: aseptic loosening (n=17), septic loosening (n=3), recurrent dislocations (n=3), traumatic loosening (n=2), neuropathy (n=1), wear (n=1), and fracture (n=1). Ten-year and 15-year survival with endpoint revision of any component for any reason was 91% and 78%. Ten-year survival with endpoint aseptic loosening was 96% for the cup and 97% for the stem. Conclusion. Performing a total hip implant in combination with acetabular bone impaction grafting in younger patients with acetabular bone stock loss seems to be an attractive approach as the long-term results are acceptable and fulfill the NICE-criteria, showing a ten -year survival of more than 90% with endpoint revisions for any reason

In a prospective study we assessed the accuracy of 3D-CT in defining the acetabular deficiency in developmental dysplasia of the hip (DDH), comparing pre-operative 3D-CT with plain radiographs, intraoperative stability testing and intraoperative acetabular morphology. Twenty children (25 hips) with DDH who had open reduction and/or pelvic osteotomy from 1999 to 2001 were studied. On 3C-CT the morphology of the deficiency was described as normal, anterolateral deficient (overlapping shadows), lateral (increased acetabular index only) and global (double acetabulum). At open reduction, the position in which the hip was most stable with axial loading was assessed (Zadeh and Caterall, 2001). The surgeon’s assessment of the acetabular morphology intraoperatively was the standard against which the other modalities were tested. One hip was normal, five had a global and 19 an anterolateral deficiency. 3D-CT correlated well with the acetabular morphology (84%). Plain radiography correlated poorly, especially with the global type (60%). Mid-superior appearance on 3D-CT and lateral appearance on plain radiograph equated with an anterolateral deficiency morphologically. In the global type the hip was unstable in all positions, while the anterolateral type, while in the anterolateral type the hip was always stable in flexion and abduction and in only 31% of hips stable also in abduction and internal rotation. The mean age at surgery was 3 years (1 to 7). The one hip with a normal acetabulum required open reduction only, the five global types an acetabuloplasty (Tonnis), and the 19 hips with anterolateral deficiency a redirectional (Salter) osteotomy. 3D-CT is helpful in appropriate osteotomy for a specific type of acetabular deficiency in DDH

Impaction bone grafting has become an established technique in restoring acetabular and femoral bone stock loss during hip replacement surgery. This study presents our preliminary results using this technique to restore acetabular bone stock loss during cemented total hip replacement, with particular reference to the use of a preformed perforated metallic mesh to contain major acetabular defects. In 52 patients (55 hips), acetabular reconstruction with impaction bone grafting was undertaken during total hip replacement (7 primary and 48 revision, of which 13 had previously undergone multiple revisions). The mean age at the time of surgery was 68 (range 34 to 88). In 31 cases (30 segmental or combined acetabular deficiencies, and one case of pelvic discontinuity) a pre-formed stainless steel mesh was utilised to contain the impacted morsellised bone graft. There were no perioperative deaths or deep infections and few complications (2 non-recurrent dislocations and 2 deep vein thromboses). At a mean follow-up of 40 months (range 18 to 91 months) there have been no revisions for any reason. Three patients who died before a minimum follow-up of 18 months have been excluded. Of the 49 patients (52 hips) remaining, clinical hip scores (Merle d’Aubigne and Postel) averaged 5.3 for pain, 4.2 for walking ability, and 5.3 for range of movement (with 16 patients in Charnley group A, 14 in group B, and 19 in group C). There was one case of radiographic loosening, with a radiolucent line > 2mm diameter in all 3 zones of DeLee and Charnley, although the cup has not migrated and the patient remains pain-free. All other cases show radiographic changes suggestive of ongoing graft incorporation. We consider that the use of preformed metallic meshes extends the scope of impaction bone grafting to include cases where major segmental acetabular deficiencies are encountered, allowing restoration of bone stock and an anatomical centre of hip rotation, with encouraging preliminary clinical and radiological results

The purpose of our study was to find out the midterm results of the Müller acetabular roof reinforcement ring in primary and revision total hip arthroplasty. From 1988 to 1998, 48 total hip arthroplasties using the acetabular roof reinforcement ring (39 patients) was performed by one surgeon (PDB). We reviewed all patients who had a minimum of five year follow up. There were 37 hips (31 patients) with a mean follow up of 7 years (5 to 12 years). Acetabular deficiencies were classified according to the AAOS classification. Acetabular reconstruction was done using the Müller acetabular roof reinforcement ring with the polyethylene cup cemented to the ring, and morcellized cancellous bone graft. Müller straight stem femoral prosthesis was used in all cases for femoral reconstruction. All patients were followed up annually and outcome assessed using Harris hip score. There were 27 primary procedures and 10 revisions. 30 patients (81%) had cavitary, 2 (5%) had segmental and 5 (14%) had combined defects. Survival analysis was done with failure defined as radiological evidence of loosening of the acetabular component. Statistical analysis was done using SPSS for Windows (SPSS Inc, Chicago, Illinois). 5 patients died due to unrelated causes and 2 patients were lost for follow up. The mean Harris hip score improved from 42 preoperatively to 82 postoperatively (p< 0. 001)(Wilcoxon Signed Rank test). Both mean pain and function score showed improvement from 12 to 39 postoperatively (p< 0. 001) and 12 to 32 (p< 0. 001) respectively. 5 patients had radiological loosening of the ring. The migration rate was 13%. The cumulative survival rate at 12 years, excluding all patients who died and were lost for follow up, was 79. 3% (95% confidence interval 71. 4 to 87. 2, standard error 4). There was no statistical difference in the failure rate between primary and revision procedures (chi-square test). This series show satisfactory medium term results with Müller roof reinforcement ring and cancellous bone graft in acetabular deficiencies with poor bone stock

Introduction and Objective. The surgical strategy for acetabular component revision is determined by available host bone stock. Acetabular bone deficiencies vary from cavitary or segmental defects to complete discontinuity. For segmental acetabular defects with more than 50% of the graft supporting the cup it is recommended the application of reinforcement ring or ilioischial antiprotrusio devices. Acetabular reconstruction with the use of the antiprotrusion cage (APC) and allografts represents a reliable procedure to manage severe periprosthetic deficiencies with highly successful long-term outcomes in revision arthroplasty. Objective. We present our experience, results, critical issues and technical innovations aimed at improving survival rates of antiprotrusio cages. Materials and Methods. From 2004 to 2019 we performed 69 revisions of the acetabulum using defrosted morcellized bone graft and the Burch Schneider anti-protrusion cage. The approach was direct lateral in 25 cases, direct anterior in 44. Patients were re-evaluated with standard radiography and clinical examination. Results. Eight patients died from causes not related to surgery, and two patients were not available for follow up. Five patients were reviewed for, respectively, non-osseointegration of the ring, post-traumatic loosening with rupture of the screws preceded by the appearance of supero-medial radiolucency, post-traumatic rupture of the distal flange, post-traumatic rupture of the cemented polyethylene-ceramic insert, and dislocation treated with new dual-mobility insert. Among these cases, the first three did not show macroscopic signs of osseointegration of the ring, and the only areas of stability were represented by the bone-cement contact at the holes in the ring. Although radiographic studies have shown fast remodeling of the bone graft and the implant survival range from 70% to 100% in the 10-year follow up, the actual osseointegration of the ring has yet to be clarified. To improve osseointegration of the currently available APC whose metal surface in contact with the bone is sandblasted, we combined the main features of the APC design long validated by surgical experience with the 3D-Metal Technology for high porosity of the external surface already applied to and validated with the press fit cups. The new APC design is produced with the 3D-Metal technology using Titanium alloy (Ti6Al4V ELI) that Improves fatigue resistance, primary stability and favorable environment for bone graft ingrowth. We preview the results of the first cases with short-term follow up. Conclusions. Acetabular reconstruction with impacted morcellized bone graft and APC is a current and reliable surgical technique that allows the restoration of bone loss with a high survival rate of the implant in the medium to long term. The new 3D Metal Cage is designed to offer high friction for the initial stability. The high porosity of the 3D Metal structure creates a favorable environment for bone growth, thus providing valid secondary fixation reproducing the results achieved with the 3D metal press fit cup

Fifty-five patients undergoing isolated acetabular revisions in fifty-seven hips were available for review. In thirty-three of fifty-seven hips there was no significant acetabular deficiency; of the remaining twenty-four hips twenty underwent allograft reconstruction and four autogenous bone grafting. Mean follow-up was four years with a range of three to seven years; there have been no femoral loosening, and three further surgical procedures for hip instability. All acetabular components at last review were soundly fixed with the exception of one patient who underwent excision arthroplasty at twelve months for deep infection. The purpose of this study was to review the functional outcome and the fate of the femoral stem and revised acetabular component following isolated ace-tabular revision. Findings of the current study demonstrate that isolated acetabular revision does not compromise the final functional nor radiographic outcome in acetabular revision in appropriately selected patients; the fate of the femoral component is not adversely influenced by this procedure. There is no need to remove the femoral component at the time of acetabular revision if the femoral component is well fixed and stable by pre- and intra-operative assessment. Prospectively entered data on fifty-seven hips (fifty-five patients) who have undergone isolated acetabular revision without femoral revision was available for review. All patients were assessed pre-operatively and post-operatively on an annual basis by means of physical examination, x-ray, SF-36 and WOMAC questionnaires. In thirty-three of fifty-seven hips there was no significant acetabular deficiency; of the remaining twenty-four hips, one had a segmental defect, thirteen had a cavitary defect and ten had a combined segmental and cavitary defect. Osteolysis existed in the proximal femur of two hips. Bone grafting in twenty-four hips consisted of morselized allograft in nine; combined structural and morselized allograft used in eleven and autogenous bone used in four acetabular defects. Autogenous bone grafting was done in two femoral osteolytic lesions. Mean follow-up was four years with a range of three to seven years. The mean duration of arthroplasty prior to revision was fourteen years (range four to twenty-three years). There were no nerve palsies, vascular injuries or intra-operative fractures in this patient group. All ace-tabular components at latest review were soundly fixed with the exception of one patient who underwent excision arthroplasty at twelve months for deep infection. Twenty-one of the twenty-four hips with bone grafting demonstrated positive radiographic signs of incorporation; the remaining threehips have a stable interface but no evidence of bone ingrowth. Three of the fifty-seven hips presented with hip dislocations after revision arthroplasty; two were managed by closed reduction; the third by open reduction and soft tissue repair

Developmental dysplasia of the hip (DDH) represents a heterogeneous group of deformities that are commonly associated with secondary osteoarthritis. Affected hips may require total hip arthroplasty (THA) for endstage disease and these cases can present unique challenges for the reconstructive surgeon. While the severity of deformity varies greatly, optimizing THA can be challenging even in the “mildly” dysplastic hip. These disorders are commonly characterised by acetabular deficiency with inadequate coverage of the anterolateral femoral head and proximal femoral abnormalities including excessive femoral antetorsion, coxa valga and femoral stenosis. In more severe cases, major femoral head subluxation or dislocation can add additional complexity to the procedure. In addition to the primary deformities of DDH, secondary deformities from previous acetabular or proximal femoral osteotomies may also impact the primary THA. Primary THA in the DDH hip can be optimised by detailed understanding of the bony anatomy, careful pre-operative planning, and an appropriate spectrum of techniques and implants for the given case. This presentation will review the abnormal hip morphologies encountered in the dysplastic hip and will focus on the more challenging aspects of THA. These include acetabular reconstruction of the severely deficient socket and in the setting of total dislocation, femoral implant procedures combined with corrective osteotomy or shortening, and issues related to arthroplasty in the setting of previous pelvic osteotomy. Despite the complexity of reconstruction for various dysplastic variants the clinical outcomes and survivorship of these procedures are good to excellent for most patients. Nevertheless, more complex procedures are associated with an increased complication rate and this should be considered in the surgical decision-making process