Structural Allograft Supporting a Trabecular Metal Cup Provides Durable Results in Complex Revision Arthroplasty.

BACKGROUND: Revision total hip arthroplasty (THA) is challenging specially in the presence of severe acetabular bone deficiency. We report the use of a highly porous revision shell augmented by structural allograft to provide structural support and coverage to the acetabular component. METHODS: We identified 56 patients (58 hips) undergoing revision THA, where a trabecular metal revision cup was supported by structural allograft. Mean follow-up was 5.4 years (range 2-12 years). Preoperatively acetabular bone defects were classified as Paprosky 2A in 6 hips (10%), 2B in 12 hips (21%), 2C in 12 hips (21%), 3A in 11 hips (19%), and 3B in 17 hips (29%). Structural allograft configuration was classified as type 1 (flying buttress) in 13 hips, type 2 (dome support) in 23 hips, and type 3 (footings) in 17 hips, with 5 hips having combined configurations. RESULTS: All hips showed evidence of union between the allograft and host bone at latest follow-up, 14 hips had partial resorption of the allograft that did not affect cup stability. Three acetabular components demonstrated failure of ingrowth. Survivorship-free from radiographic acetabular loosening as end point was 94% at 5 years. The 5-year survivorship with revision for any reason as end point was 90%. CONCLUSION: Trabecular metal shells combined with structural bone allograft in revision THA demonstrate excellent midterm survival, with 94% of acetabular components obtaining stable union onto host bone at 5 years. Allograft restored bone stock with minimal resorption, and when it occurred did not alter the survivorship of the acetabular component.

There Are No Differences in Short- to Mid-term Survivorship Among Total Hip-bearing Surface Options: A Network Meta-analysis.

BACKGROUND: Total hip arthroplasty (THA) is increasingly being performed in patients with long life expectancies and active lifestyles. Newer implant bearing surfaces, with superior wear characteristics, often are used in this cohort with the goal of improving longevity of the prosthesis, but comparisons across the numerous available bearing surfaces are limited, so the surgeon and patient may have difficulty deciding which implants to use. QUESTIONS/PURPOSES: The purpose of this study was to answer the following question: Is there a short- to mid-term survivorship difference between common THA bearings used in patients younger than age 65 years? METHODS: We conducted a systematic review to identify randomized clinical trials (RCTs) published after 2000 that reported survivorship of ceramic-on-ceramic (CoC), ceramic-on-highly crosslinked polyethylene (CoPxl), or metal-on-highly crosslinked polyethylene (MoPxl) bearings. To qualify for our review, RCTs had to have a minimum 2-year followup and study patients were required to have an average age younger than 65 years. Direct-comparison meta-analysis and network meta-analysis were performed to combine direct and indirect evidence. RESULTS: Direct-comparison meta-analysis found no differences among the bearing surfaces in terms of the risk of revision; this approach demonstrated a risk ratio for revision of 0.65 (95% confidence interval [CI], 0.19-2.23; p = 0.50) between CoC and CoPxl and a risk ratio for revision of 0.40 (95% CI, 0.06-2.63; p = 0.34) between CoC and MoPxl. Network meta-analysis (with post hoc modification) likewise found no differences in survivorship across the three implant types, demonstrating the following probabilities of most effective implant with 95% credible intervals (CrI): CoC = 64.6% (0%-100%); CoPxl = 24.9% (0%-100%); and MoPxl = 9.9% (0%-100%). The CrIs ranged from 0% to 100% for all three bearing surfaces. Direct-comparison meta-analysis allowed for pooling of five RCTs, including 779 THAs, whereas network meta-analysis (before post hoc analysis) enabled pooling of 18 RCTs, including 2599 THAs. CONCLUSIONS: Current published evidence does not support survivorship differences among commonly used bearing surfaces in patients younger than age 65 years undergoing THA at short- to mid-term followup. Long-term RCT data will be needed to determine if a survivorship benefit is realized in younger, more active patients over time. LEVEL OF EVIDENCE: Level I, therapeutic study.

Uncemented acetabular components with femoral head autograft for acetabular reconstruction in developmental dysplasia of the hip: a concise follow-up report at a mean of twenty years.

We previously reported the five to twelve-year results of total hip arthroplasty with an uncemented acetabular component and an autogenous femoral head graft in forty-four consecutive hips with developmental dysplasia. The goal of the present study was to report the implant survival rate, status of bone grafts, and clinical outcomes in thirty-five of these hips (in twenty-nine patients) followed for a mean of 21.3 years. Functional, radiographic, and survivorship results were examined. Radiographic analysis revealed an average cup inclination angle of 43° and a mean arc of cup coverage by the graft of 30°. The twenty-year survivorship free from acetabular revision was 66% (twelve acetabular revisions; eight since our previous report). Of the twelve revisions, nine were for liner wear and/or osteolysis, one was for a liner fracture, one was for aseptic loosening, and one was for instability. All bone grafts healed to the pelvis. The graft facilitated revision cup placement as no additional structural grafts or metal augments were required. We concluded that an uncemented porous-coated socket used in conjunction with a bulk femoral head autograft provides good long-term fixation and restores bone stock.

Risk stratification algorithm for management of patients with dual modular taper total hip arthroplasty: consensus statement of the American Association of Hip and Knee Surgeons, the American Academy of Orthopaedic Surgeons and the Hip Society.

Although 'dual taper' modular stems with interchangeable modular necks have the potential to optimize hip biomechanical parameters, there is increasing concern regarding the occurrence of adverse local tissue reactions from mechanically assisted crevice corrosion at the neck-stem taper junction. A systematic treatment approach (risk stratification algorithm) based on the currently available data is recommended to optimize patient management. While specialized tests such as metal ion analysis and MARS MRI are useful modalities in evaluating for adverse tissue reactions, over-reliance on any single investigative tool in the clinical decision-making process should be avoided. There should be a low threshold to perform a systematic evaluation of patients with dual taper stem total hip arthroplasty as early recognition and diagnosis will facilitate the initiation of appropriate treatment.

Comparative Survivorship of Different Tibial Designs in Primary Total Knee Arthroplasty.

BACKGROUND: Few registry-based studies in the United States have compared the survivorship of different knee implant designs in total knee arthroplasty. The purpose of this study was to compare differences in survivorship of commonly used tibial implant designs in primary total knee arthroplasty. METHODS: A total of 16,584 primary total knee arthroplasties in 11,992 patients were performed at a single institution from 1985 to 2005. Patients were prospectively followed at regular intervals to ascertain details of subsequent revisions. Overall revision rates and revisions for aseptic loosening, wear, and osteolysis were compared across twenty-two tibial implant designs using Cox proportional hazards regression models adjusting for age, sex, calendar year, and body mass index. RESULTS: In comparison with metal-backed modular implants, all-polyethylene tibial components had a significantly lower risk of revision (hazard ratio, 0.3; 95% confidence intervals: 0.2, 0.5 [p < 0.0001]). The risk reduction with all-polyethylene tibial components was not affected by age, sex, or body mass index. With metal-backed modular tibial designs, cruciate-retaining knees performed better than the posterior-stabilized knees (p = 0.002), but this finding was limited to one specific metal-backed modular tibial component, the Press Fit Condylar design. With all-polyethylene tibial components, there was no survivorship difference between cruciate-retaining and posterior-stabilized designs. CONCLUSIONS: All-polyethylene tibial components were associated with better outcomes than metal-backed modular components. Cruciate-retaining and posterior-stabilized designs performed equally well, except with the Press Fit Condylar design. Obese patients may have superior results with all-polyethylene and posterior-stabilized components. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Risk stratification algorithm for management of patients with metal-on-metal hip arthroplasty: consensus statement of the American Association of Hip and Knee Surgeons, the American Academy of Orthopaedic Surgeons, and the Hip Society.

There should be a low threshold to perform a systematic evaluation of patients with MoM hip arthroplasty as early recognition and diagnosis will facilitate the initiation of appropriate treatment prior to significant adverse biological reactions. A painful MoM hip arthroplasty has various intrinsic and extrinsic causes, and a systematic treatment approach based on the currently available data is presented to optimize management of MoM patients. The risk stratification algorithm presented will continue to develop as further evidence becomes available providing additional insights. While specialized tests such as metal ion analysis are useful modalities for assessing MoM hip arthroplasty, over-reliance on any single investigative tool in the clinical decision-making process should be avoided. Future research focusing on validation of the current diagnostic tools for detecting adverse local tissue reactions as well as optimization of MoM bearings and modular connections to further diminish wear and corrosion is warranted.

Comparative long-term survivorship of uncemented acetabular components in revision total hip arthroplasty.

BACKGROUND: It is unknown whether the long-term survival of uncemented acetabular components in revision total hip arthroplasty varies according to component type. The purpose of this study was to compare the survivorship of historical and current uncemented acetabular components following revision total hip arthroplasty. METHODS: The study population included 3236 patients who underwent 3448 revision total hip arthroplasty procedures with an uncemented acetabular component at a large United States medical center between January 1, 1984, and December 31, 2004. Patients were actively followed up at regular intervals to ascertain details of subsequent revision surgical procedures, including cup (metal shell plus liner) and liner revisions. The overall survival and the cause-specific survival of ten different acetabular components were compared with use of Cox proportional-hazards regression models, adjusting for age and sex. RESULTS: A total of 605 repeat revisions, including 386 cup revisions, were performed. The corresponding overall survival rate at fifteen years was 69% (95% confidence interval [CI], 67% to 72%). Compared with titanium wire mesh designs, cup revision for aseptic loosening was significantly more common with beaded designs (hazard ratio [HR], 2.01; 95% CI, 1.44 to 2.80) but less common with trabecular metal designs (HR, 0.25; 95% CI, 0.06 to 1.04). There were no liner revisions for wear and/or osteolysis during a median of 5.2 years of follow-up of 534 total hip arthroplasties with cross-linked polyethylene liners, resulting in a significantly lower risk of wear-related revision with cross-linked polyethylene compared with conventional liners. Femoral head size and use of an elevated liner were not associated with the risk of repeat revision. CONCLUSIONS: In the setting of revision total hip arthroplasty, cup survival was worse with beaded acetabular designs compared with titanium wire mesh or highly porous designs. Cross-linked polyethylene liners were associated with a reduced risk of wear-related liner revision.

Primary total knee arthroplasty in patients with fibromyalgia.

No data on the results of total knee arthroplasty (TKA) in patients with fibromyalgia have been published. The purposes of this study were to review a cohort of patients with fibromyalgia undergoing TKA to determine the level of postoperative pain and satisfaction with the surgery, the incidence of postoperative surgical complications, and revision rates and their relationship to TKA design. One hundred ten patients with fibromyalgia (141 knees) who underwent primary TKA between 1990 and 2001 were studied. The average age was 64 years (range, 39-86 years), and the average follow-up was 7 years (range, 2-16 years). Forty-five knees were cruciate retaining, and 96 had a posterior stabilized design. Clinical outcome was assessed using the Knee Society Knee Score and satisfaction regarding the results of the procedure. Postoperative surgical complications and reoperations were obtained from the registry. Sixty-two patients (44%) continued with some pain after TKA. Eighty-five patients (82%) were satisfied with the results. The most common complications were arthrofibrosis and symptomatic instability. The revision rate was 6% (8 knees). Survivorship free from revision at 7 years was 89% for cruciate retaining knees and 98% for posterior stabilized knees. Patients with fibromyalgia undergoing primary TKA have a high prevalence of complications and pain. Despite continued pain, the majority of patients were satisfied with the results and reported improvements after TKA. This data should be used to counsel patients with fibromyalgia preoperatively regarding limited goals with respect to pain relief and suggests that a multimodal individualized treatment program may be necessary to achieve optimal outcomes in patients with fibromyalgia.

Ceramic-on-ceramic total hip arthroplasty in patients younger than 20 years.

Total hip arthroplasty (THA) in the adolescent patient has historically shown relatively poor survivorship. This study reports the results of THA in young patients using contemporary ceramic bearings. Twenty-four THAs were performed using ceramic bearing surfaces in patients 20 years old or younger (mean, 16.4; range, 12-20). Average follow-up was 52 months (range, 25-123 months). The survival rate was 96%, with 1 revision for a loose acetabular component. Other complications included a peroneal nerve palsy that resolved and 2 dislocations in 1 patient. Postoperatively, the Modified Harris Hip Score mean was 93.4 (range, 66-100). This study shows promising results at short-term to midterm follow-up in very young patients who undergo THA using ceramic-on-ceramic components.

Effectiveness of false profile radiographs in detection of pelvic discontinuity.

Pelvic dissociation is a rare but serious potential complication of total hip arthroplasty. The purpose of this study is to evaluate the effectiveness of the false profile view compared with traditional radiographs in detecting pelvic dissociation. Ten cadaver pelves were skeletonized, and noncemented acetabular hip arthroplasty components were implanted. Anteroposterior, lateral, iliac oblique, and false profile radiographs were obtained before and after creating pelvic dissociations and analyzed in a blinded fashion. The sensitivity of the false profile view for detecting pelvic dissociation was 79% (confidence interval, 70-86), which was greater than the sensitivity for anteroposterior and lateral views. This difference was statistically significant. False profile views are a potentially valuable addition to the traditional radiographic evaluation of pelvic discontinuity in hip arthroplasty.

Comparative survival of uncemented acetabular components following primary total hip arthroplasty.

BACKGROUND: Since their initial introduction in the early 1980s, uncemented acetabular components have become the preferred implant type for the majority of hip arthroplasties performed in the United States. The purpose of the present study was to compare differences in the survival of uncemented acetabular components following primary total hip arthroplasty. METHODS: The study population included 7989 patients who had undergone 9584 primary total hip arthroplasties with twenty different types of uncemented acetabular components at the Mayo Clinic from January 1984 to December 2004. The overall rate of survival as well as the rate of survival free of revision for specific reasons (aseptic loosening, wear, osteolysis) were compared among the different components using age and sex-adjusted Cox proportional hazards regression models. RESULTS: The risk of acetabular cup revision was significantly higher for beaded and hydroxyapatite-coated designs as compared with titanium wire mesh designs. Cross-linked polyethylene performed better than conventional polyethylene, but this finding did not reach significance. Elevated liners were associated with a significantly higher risk of cup revision due to aseptic loosening. CONCLUSIONS: There are significant differences in the long-term survival of different types of uncemented acetabular components following total hip arthroplasty. The increased risk of revisions in the second decade after the initial total hip arthroplasty is a concern and is largely due to a steady increase in revisions because of polyethylene wear, osteolysis, and component loosening more than ten years after the time of the index arthroplasty.

Cementless acetabular revision: past, present, and future. Revision total hip arthroplasty: the acetabular side using cementless implants.

BACKGROUND: Acetabular revision is probably the most difficult aspect of hip reconstructive surgery. Although the majority of acetabular revisions can be performed using an uncemented hemispherical acetabular device with ancillary fixation, patients with severe acetabular deficiencies and poor bone quality require more complex alternatives for revision. The limitations of traditional cementless acetabular implants has promoted the development of improved methods of fixation and revision techniques. Highly porous metals have been introduced for clinical use in arthroplasty surgery over the last decade. Their higher porosity and surface friction are ideal for acetabular revision, optimising biological fixation. The use of trabecular metal cups in acetabular revision has yielded excellent clinical results. PURPOSE: This review focuses on the use of cementless implants for acetabular revision. The use of trabecular metal cups, augments, jumbo cups, oblong cups, cages, and structural grafting are also discussed.

Failure of larger-diameter metal-on-metal total hip arthroplasty resulting from anterior iliopsoas impingement.

Anterior iliopsoas impingement is a recognized cause of persistent groin pain after total hip arthroplasty. We report 3 patients with failed total hip arthroplasties resulting from anterior iliopsoas and capsular impingement secondary to a metal femoral ball with a diameter larger than the native femoral head. All patients had the same implant design. Resolution of symptoms occurred in all patients after revision surgery. To our knowledge, this is the first report of this potential failure mechanism with these large-diameter implant designs and should be considered in the appropriate clinical scenario.

Total hip arthroplasty with shortening subtrochanteric osteotomy in Crowe type-IV developmental dysplasia: surgical technique.

BACKGROUND: When surgeons perform total hip arthroplasty for hips with a high dislocation related to developmental dysplasia of the hip, obtaining long-term stable implant fixation and optimizing patient function remain challenges. The purpose of this paper was to evaluate the results of cementless arthroplasty with a simultaneous subtrochanteric shortening osteotomy in a group of patients with Crowe type-IV developmental dysplasia of the hip. METHODS: In a retrospective study, we evaluated the results and complications of twenty-eight consecutive primary cementless total hip arthroplasties in twenty-four patients (twenty women and four men), all of whom had Crowe type-IV developmental dysplasia of the hip. The arthroplasty was performed in combination with a subtrochanteric shortening osteotomy and with placement of the acetabular component at the level of the anatomic hip center. The patients were evaluated at a mean of 4.8 years postoperatively. RESULTS: The mean Harris hip score increased from 43 points preoperatively to 89 points at the time of final follow-up (p < 0.01). Twelve (43%) of the twenty-eight hips had an early or late complication or a reoperation. Two (7%) of the twenty-eight subtrochanteric osteotomies were followed by nonunion. There was one instance of isolated loosening of the femoral stem. One acetabular component loosened, and one acetabular liner disengaged. Four hips dislocated postoperatively. All remaining components were well-fixed at the time of the last radiographic follow-up. No sciatic neurapraxic injuries were identified. CONCLUSIONS: Cementless total hip arthroplasty combined with a subtrochanteric femoral shortening osteotomy in patients with a high hip dislocation secondary to developmental dysplasia was associated with high rates of successful fixation of the implants and healing of the osteotomy site and a mean postoperative Harris hip score of 89 points. The complication rate, however, was substantially higher than that associated with primary total hip arthroplasty in patients with degenerative arthritis.

Closing wedge osteotomy of the tibia and the femur in the treatment of gonarthrosis.

New developments in osteotomy techniques and methods of fixation have caused a renewed interest in closing wedge osteotomies of the tibia and femur in the treatment of gonarthrosis. The rationale, definition and techniques of closing wedge tibial and femoral osteotomies in the treatment of gonarthrosis are discussed. The principal indications include unicompartmental medial and much less so, varus knee gonarthrosis and unicompartmental lateral or valgus knee gonarthrosis with a well-maintained range of motion in patients who are physiologically young. Newer techniques have provided more rigid fixation and improved accuracy of correction.

Total hip arthroplasty with shortening subtrochanteric osteotomy in Crowe type-IV developmental dysplasia.

BACKGROUND: When surgeons perform total hip arthroplasty for hips with a high dislocation related to developmental dysplasia of the hip, obtaining long-term stable implant fixation and optimizing patient function remain challenges. The purpose of this paper was to evaluate the results of cementless arthroplasty with a simultaneous subtrochanteric shortening osteotomy in a group of patients with Crowe type-IV developmental dysplasia of the hip. METHODS: In a retrospective study, we evaluated the results and complications of twenty-eight consecutive primary cementless total hip arthroplasties in twenty-four patients (twenty women and four men), all of whom had Crowe type-IV developmental dysplasia of the hip. The arthroplasty was performed in combination with a subtrochanteric shortening osteotomy and with placement of the acetabular component at the level of the anatomic hip center. The patients were evaluated at a mean of 4.8 years postoperatively. RESULTS: The mean Harris hip score increased from 43 points preoperatively to 89 points at the time of final follow-up (p < 0.01). Twelve (43%) of the twenty-eight hips had an early or late complication or a reoperation. Two (7%) of the twenty-eight subtrochanteric osteotomies were followed by nonunion. There was one instance of isolated loosening of the femoral stem. One acetabular component loosened, and one acetabular liner disengaged. Four hips dislocated postoperatively. All remaining components were well-fixed at the time of the last radiographic follow-up. No sciatic neurapraxic injuries were identified. CONCLUSIONS: Cementless total hip arthroplasty combined with a subtrochanteric femoral shortening osteotomy in patients with a high hip dislocation secondary to developmental dysplasia was associated with high rates of successful fixation of the implants and healing of the osteotomy site and a mean postoperative Harris hip score of 89 points. The complication rate, however, was substantially higher than that associated with primary total hip arthroplasty in patients with degenerative arthritis.