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Aims: Reconstruction of the acetabulum after failed total hip arthroplasty (THA) can be a surgical challenge in the presence of severe bone loss. We report the long-term survival of a porous tantalum revision acetabular component, its radiological appearance and quality of life outcomes., Patients and Methods: We reviewed the results of 46 patients who had undergone revision of a failed acetabular component with a Paprosky II or III bone defect and reconstruction with a hemispherical, tantalum acetabular component, supplementary screws and a cemented polyethylene liner., Results: After a minimum follow-up of ten years (ten to 12), the survivorship of the porous tantalum acetabular component was 96%, with further revision of the acetabular component as the end point. The ten-year survivorship, with hip revision for any reason as the end point, was 92%. We noted excellent pain relief (mean Western Ontario and McMaster Universities Arthritis Index (WOMAC) score pain 92.6, (40 to 100)) and good functional outcomes (mean WOMAC function 90.3 (30.9 to 100), mean University of California Los Angeles activity scale 5 (2 to 10)) and generic quality of life measures (mean Short Form-12 (SF-12) physical component 48.3 (18.1 to 56.8), mean SF-12 mental component 56.7 (32.9 to 70.3)). Patient satisfaction with pain relief, function and return to recreational activities were excellent., Take Home Message: Uncemented acetabular reconstruction using a tantalum acetabular component gives excellent clinical and quality of life outcomes at a minimum follow-up of ten years. Cite this article: Bone Joint J 2016;98-B:767-71., (©2016 The British Editorial Society of Bone & Joint Surgery.)

Correct orientation of the acetabular cup considering patient-specific functional pelvic angles is an important factor for improving outcomes and avoiding complications after total hip arthroplasty. This study introduces a new, noninvasive radiographic tool for accurately determining a patient's specific pelvic tilt angle preoperatively, as well as accurately assessing acetabular cup orientation with respect to bony landmarks intraoperatively and postoperatively. The method was validated by imaging a bone replica model of the pelvis with implanted hip components, in comparison to digitized references, and verified with a cadaveric specimen. Pelvic tilt was measured with an accuracy of 0.1 deg and SD of 0.4 deg. Operative cup inclination and anteversion showed accuracies of 0.6 deg and 2.5 deg, with SD of 0.4 deg and 0.6 deg, respectively; these could be improved further by subtracting systematic bias. The method shows accuracy advantages over existing radiographic and fluoroscopic methods and exposes the subjects to a lower radiation dose compared to the similar computed tomography methods. These results suggest that the proposed method is feasible for assessing cup placement with reference to the functional and anatomical references. Furthermore, the ability to reference the same bony landmarks preoperatively, intraoperatively, and postoperatively has important research and clinical advantages.

In cementless revision total hip arthroplasty (THA), achieving initial implant stability and maximising host bone contact is key to the success of reconstruction. Porous tantalum acetabular shells may represent an improvement from conventional porous coated uncemented cups in revision acetabular reconstruction associated with severe acetabular bone defects. We reviewed the results of 46 acetabular revisions with Paprosky 2 and 3 acetabular bone defects done with a hemispheric, tantalum acetabular shell and multiple supplementary screws. At a mean follow-up of 40 (24-51) months, one acetabular shell had been revised in a patient with a Paprosky 3B defect. Cementless acetabular revision with the tantalum acetabular shell demonstrated excellent early clinical and radiographic results and warrants further evaluation in revision acetabular reconstruction associated with severe acetabular bone defects.

We have undertaken a prospective evaluation of health-related quality-of-life outcomes in 26 consecutive patients undergoing periacetabular osteotomy with a minimum follow-up of 24 months (24 to 42). The Western Ontario-Macmaster (WOMAC) and Short Form 36 (SF-36) outcome measures were evaluated preoperatively and at follow-up. Secondary outcome measures included retrospective assessment of sports activity and satisfaction with the procedure. Follow-up data were available for 22 patients (85%). A significant improvement in the pain (p < 0.0001) and function (p < 0.0001) scales of the WOMAC and the SF-36 physical score (p < 0.0001) was seen. The mean sports activity score improved from 1.9 to 4.4, with a very high mean satisfaction rating of 89.7/100. A significant improvement in both global and disease-specific health outcomes can be expected after this operation, with a high rate of satisfaction and improvement in sporting activities.

Three classifications for assessment of acetabular bone loss were evaluated for their reliability. The 3 systems assessed were the system described by Gross, the system described by Paprosky, and the classification of the American Academy of Orthopaedic Surgeons. In this study, we assessed their reliability based on the preoperative radiographs alone. Intraobserver agreement was measured by evaluating the classifications by the 3 innovators, 3 reconstructive orthopaedic surgeons, and 3 residents. Interobserver agreement was assessed among the reconstructive surgeons and the residents. The unweighted kappa statistic was used to establish levels of agreement. The innovators had better intraobserver agreement than the other 2 groups. Their agreement was only in the moderate range, however. For the noninnovators, intraobserver and interobserver agreement generally was poor for all 3 classifications assessed. Our results indicate that these classifications do not provide statistically reliable information for preoperative assessment of acetabular bone stock loss.

We have previously described a simple and reproducible three-dimensional technique of CT for the measurement of the cover of the femoral head in acetabular dysplasia in adults. We now describe the application of this technique in ten patients with symptomatic dysplasia to assess the degree and direction of dysplasia and to measure the cover obtained at acetabular osteotomy. The indices obtained gave a useful indication of the degree and direction of the dysplasia and confirmed which components had been used most efficiently to achieve cover. The information is easily presented in graphical form and gives a clearer indication of the cover obtained than the indices derived from plain radiographs.

A number of classification systems have been proposed for periprosthetic fractures of the femur following total hip replacement. Most of these rely purely on the site and pattern of the fracture. However, it is only after consideration of other important factors, including the stability of the prosthesis as well as the quality of the surrounding bone stock, that appropriate management can be instituted. The authors have developed a new classification system that addresses these other important factors. The authors believe that only after classifying a periprosthetic fracture with specific reference to fracture site, stability of the implant, and quality of the surrounding bone stock, can one make a rational decision towards a treatment algorithm.

Aseptic loosening remains the leading cause of failure after total hip replacement. Extensive bone loss and acetabular bone stock deficiency are frequently encountered. Simple autografting techniques are often not possible, and copious amounts of allograft may be required to reconstruct the defect. The mechanically stable environment that is a prerequisite for successful graft incorporation cannot be achieved with routine acetabular fixation techniques alone. A reconstruction ring that is secured to the surrounding pelvis provides a more rigid construct. Several types of reconstruction rings are available for the management of acetabular bone loss during revision hip surgery. Early results suggest that these devices may prove to be a useful alternative for treatment of a difficult problem.

Objective: To assess a three-dimensional computed tomography (3DCT) technique for measurement of acetabular coverage in adults., Design: We used 3DCT to define the geometric centre of the femoral head and to measure centre-edge angles (CEAs) at 10 degrees rotational increments around the acetabular rim. The means, ranges, standard deviations and 95% confidence intervals for the CEAs at the various rotational increments were determined. Inter- and intra-observer variability was measured. The normal values are compared with two example cases of acetabular dysplasia., Patients: The normal hips of 15 subjects aged 1949 years (mean 34.2 years) were measured., Results: The 3DCT measurements are reproducible (mean difference interobserver, 1.7 degrees - 7.9 degrees; mean difference intra-observer, 0.6 degrees-6.9 degrees). Mean normal CEA at the lateral rim was 33 degrees with a 95% confidence interval of 23 degrees - 43 degrees. Mean normal CEAs at 10 rotational increments from anterior to posterior rim were determined, and graphed as a 'normal curve'., Conclusion: This new 3DCT method of assessing acetabular dysplasia is simple, reproducible, and applicable to diagnosis, quantification and surgical planning for adult acetabular dysplasia patients.

Acetabular reconstruction in both primary and revision hip arthroplasty often requires reconstruction of deficient acetabular bone stock. The exact role of allografts remains controversial. Published results of structural allografting are presented. Recent literature supports the use of segmental allografts for reconstruction of large segmental and combined defects.

The results of the placement of a massive structural acetabular allograft in conjunction with a revision total hip arthroplasty in thirty-two patients (thirty-tree hips) were evaluated at a minimum of five years. The graft supported more than 50 percent of the cup in all of the patients. The goals of a revision operation in a hip that has massive loss of bone are to provide support for the cup, to approximate the normal anatomy, to restore the length of the lower limb, and to restore bone stock should a future revision be necessary. Clinical and radiographic review at an average of seven years (range, five to eleven years) after the revision revealed that eighteen hips had needed no additional operation, seven hips had needed a repeat revision but the structural allograft was intact and had been used to support the cup at the repeat revision, and eight hips had had failure of both the prosthesis and the allograft. The result was considered a clinical and radiographic success when the hip score had increased at least 20 points, the cup was stable, the allograft had united, and no additional operation was necessary. According to these criteria, the rate of success was 55 percent (eighteen of thirty-three hips.) The only factor that was found to be clinically important with respect to outcome was the method of reconstruction. Seven of the eight hips that had been reconstructed with use of a roof-reinforcement ring and a structural allograft had a successful result at an average of 7.5 years (range, five to eleven years). The findings of the present study support the use of a structural allograft in the presence of massive loss of bone in order to achieve the goals of a revision hip replacement. Because of the high rate of success with acetabular reinforcement rings, we now use this method of reconstruction whenever a massive allograft is employed on the acetabular side.

Revision acetabular surgery with bone stock loss is a difficult problem. Defects are classified into contained cavitary (Type-1) defects and noncontained defects (Type 2A and 2B) based on preoperative radiographs and intraoperative findings. Fifty-four hips with Type-1 defects were treated with morsellized allograft. The overall success rate was 90% at 6.78 year followup. Type-2 defects are reconstructed with structural grafts. Twenty-nine hips with Type-2A defects (the allograft supports <50% of the cup) were reviewed at 7.1 years' followup. The success rate was 90)%. In all but 1 case the allograft united to host bone. No resorption or minor resorption was seen in 26 of 29 hips with minor column structural grafts. Type-2B defects all had structural allografts that supported >50% of the cup. There were 33 hips in this group observed for an average of 7.1 years. The rerevision rate in this group was 45%. However, 7 of 15 hips were reconstructed without additional graft at rerevision. The only factor that was clinically significant for success in Type-2B defects was choice of acetabular component. In hips that received roof rings with cemented cups, the success rate was 100% (excluding 1 infection). The authors support the use of allograft bone in revision acetabular surgery. When structural grafts are required, every attempt should be made to achieve >50% support from host bone. If this is not possible, then a roof reinforcement ring with a cemented cup is the acetabular component of choice.

A series of 29 shelf ( < 50% of the acetabulum) structural allografts were done in conjunction with acetabular revision with a minimum follow-up period of 5 years (average, 7.1 years). At the latest follow-up examination, 86% of the hips were successful both clinically and radiologically. Only four patients required further surgery, with two of these being revised with no additional grafts. The use of bulk allograft in conjunction with acetabular revision is supported, provided that at least 50% support of the cup can be obtained with host-bone. This type of reconstruction provides support for the cup and restores anatomy, leg length, and bone stock should future revision be necessary.

A series of 33 hips treated with cementless cups and structural autograft or allograft were reviewed at a minimum follow-up period of 5 years. Seventeen hips received a shelf autograft during primary hip arthroplasty and 16 received an allograft at revision. In the hips receiving autografts, the average preoperative hip score was 45.1 and the score at final review was 87.5, whereas in the revisions reconstructed with allografts, the average preoperative hip score was 44.4 and the score at final review was 82. Overall, only 2 of 33 hips were considered failures, giving a success rate of 94% at an average follow-up period of 6.6 years. Leg-length discrepancy greater than 2 cm was seen in 27 of 33 hips, and at final review only 4 of 33 hips had a leg-length discrepancy greater than 2 cm. All grafts united to host-bone. Resorption, when seen, was minor, with only three grafts showing moderate resorption. Our data support the use of cementless cups with structural allografts and autografts, provided the graft supports less than 50% of the cup.