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.

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.

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.

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.

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.

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.

Midterm to long-term followup of staged reimplantation for infected hip arthroplasty.

UNLABELLED: Most reports on two-stage reimplantation have focused on the short-term cure rate of infection, but little is known about long-term reinfection-free survival or mechanical durability. We retrospectively reviewed 168 patients (169 hips) with infected arthroplasty, all of whom had two-stage reimplantation for the treatment of an infected total hip arthroplasty between 1988 and 1998. In the second stage, the femoral component was fixed with antibiotic-loaded bone cement in 121 hips; the remaining femoral components and all acetabular components were uncemented. The minimum followup time was 2 years (mean, 7 years; range, 2-16 years). At most recent followup, 12 hips (7.1%) were reoperated on for reinfection and 13 hips (7.7%) were revised for aseptic loosening or osteolysis. Apparently aseptic loosening occurred on one or both sides of the joint in 24 hips (14.2%). The 10-year survivals free of reinfection and mechanical failure were 87.5% and 75.2% respectively. Nineteen hips dislocated and eight underwent revision surgery for instability. The method of femoral component fixation, either with or without cement, did not correlate with risk of infection, loosening, or mechanical failure. Based on these results, the method of fixation used for the femoral component during two-stage reimplantation surgery should be based on the surgeon's preference for fixation combined with the assessment of femoral bone stock. LEVEL OF EVIDENCE: Level IV, case series. See the Guidelines for Authors for a complete description of levels of evidence.

Hip arthroplasty after previous arthrodesis.

UNLABELLED: Total hip arthroplasty after previous arthrodesis has been associated with increased complications and decreased survivorship of the prosthesis. We evaluated pain, function, and the factors influencing survivorship of total hip arthroplasties after previous arthrodesis between 1985 and 2000 and compared these results with those obtained in prior years with the same procedure and in the same institution. We retrospectively reviewed 30 patients who had previous spontaneous or surgical arthrodesis. The minimum followup was 2 years (mean, 10.4 years; range 2-20.5 years). Seven failures were identified (23%). The overall survival free of failure was 86% at 5 years and 75% at 10 years. At last followup, 27 of the 30 patients (91%) had no or slight pain, 26 (87%) had a limp, and 18 (61%) needed a gait aid. Surgical arthrodesis, age younger than 50 years at the time of arthroplasty, and length of arthrodesis less than 30 years independently predicted failure. Conversion of arthrodesis to hip arthroplasty reliably decreases pain and improves function, but many patients will limp and require a gait aid. Our outcomes were similar to those after revision rather than after primary hip arthroplasty. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Hip resurfacing arthroplasty: risk factors for failure over 25 years.

UNLABELLED: Many early metal-on-polyethylene hip resurfacing arthroplasty designs were abandoned after reports of high short-term and midterm failure rates. To investigate factors associated with failure, we retrospectively reviewed our experience with early-design hip resurfacing implants in 75 patients during a 25-year period (median followup, 7.9 years; range, 0.1-25.2 years). Implant failure was defined as revision for any reason. One of 75 patients was lost to followup. The estimated rate of implant survival was 73% at 5 years, 34% at 10 years, 27% at 15 years, 12% at 20 years, and 8% at 25 years. Of the many clinical and radiographic factors considered, only age, implant type, and gender were associated with implant survival independent of other variables considered. Hip resurfacing arthroplasty showed poor overall long-term survival in this series. Particular attention should be paid to the identified risk factors as long-term followup data become available for modern designs. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Long-term incidence of subaxial cervical spine instability following cervical arthrodesis surgery in patients with rheumatoid arthritis.

OBJECTIVE: Cervical spine deformities are well-known complications of RA. A 5- to 20-year follow-up of 51 consecutive rheumatoid patients who underwent posterior cervical arthrodesis is presented to evaluate the recurrence of instability and need for further surgery. METHODS: We conducted a retrospective review of the clinical features of 11 men and 40 women with an established diagnosis of RA and associated cervical deformities who underwent cervical spine surgery at the Mayo Clinic (Rochester, MN) between 1979 and 1990. Their mean age was 61 +/- 10 years (SD), and their duration of RA averaged 21 +/- 8.9 years (SD). There were 22 patients who presented with myelopathy, 7 with radiculopathy, and 22 with instability/neck pain. There were 33 patients with AAS, 2 with SMO process into the foramen magnum, 8 with SAS, and 8 with combinations of these. Preoperative reduction was followed by decompression and fusion using wiring techniques and autologous bone graft. Postoperative halo orthosis was provided for at least 3 months. The mean follow-up was 8.3 +/- 6 years (SD). RESULTS: There were 31 patients (61%) who underwent atlantoaxial arthrodesis, 17 patients (33%) who underwent subaxial, and 3 patients (6%) who underwent occipitocervical arthrodesis. During follow-up, 39% (13/33) of patients with AAS developed nonsymptomatic (6) or symptomatic/unstable (7) SASs subsequent to C1-C2 fusion. The latter 7 patients (21%) subsequently required extension of their arthrodesis. Adjacent segment disease was most common at the C3-C4 interspace after atlantoaxial fusion in 62% (8/13). Among the 8 patients who underwent isolated cervical fusion for SAS, 1 patient (1/8, 12%) developed adjacent instability after a fall and required extension of the previous fusion. No secondary procedure was required for the 6 patients initially stabilized by C1-(C6-T1) fusions for combinations of AAS + SAS. None of the patients initially treated by C1-C2 arthrodesis for AAS progressed to SMO. CONCLUSIONS: The incidence of subaxial instability in patients with rheumatoid disease who underwent cervical arthrodesis may be higher than previously reported, indicating the need for continued follow-up in these patients. Adjacent segment disease may be most common at the C3-C4 level following atlantoaxial fusion. Early stabilization of the C1-C2 complex in the patients with AAS may potentially prevent progression of SMO.

Impaction bone grafting for revision hip arthroplasty: biology and clinical applications.

Impaction bone grafting techniques are useful when the orthopaedic surgeon is faced with large cavitary acetabular defects or a large ectatic femoral metaphysis or diaphysis. Impaction bone grafting of the acetabulum involves packing of cavitary defects with compressed particulate graft, followed by insertion of either a cemented or cementless acetabular component. Impaction grafting of the femur involves retrograde filling of the femoral canal with impacted particulate graft, creating a neomedullary canal into which a cemented femoral stem can be placed. Use of the impaction allografting technique is appealing, especially in young patients, because of its potential to restore bone stock. The technically demanding nature of the procedure, the risk of complications, and the unknown long-term fate of the impacted allograft highlight the need for ongoing assessment of this technique for revision total hip arthroplasties.

Early postoperative transverse pelvic fracture: a new complication related to revision arthroplasty with an uncemented cup.

BACKGROUND: Uncemented hemispherical cups are commonly used to revise failed acetabular total hip components, even in the presence of marked acetabular bone loss. The purpose of the present study was to report a new complication of acetabular component revision with an uncemented hemispherical cup. METHODS: We retrospectively reviewed the records of seven patients (seven hips) in whom an early postoperative transverse acetabular fracture had developed following the implantation of an uncemented trabecular metal cup for the revision of a failed acetabular component. All patients were female. The average age was 63.6 years. The reason for acetabular revision was aseptic loosening of the original cup in five patients and reimplantation after a previous resection arthroplasty in the remaining two. The average cup size used for revision was 58 mm. In two hips, additional modular acetabular metal augments were used to restore the acetabular rim. RESULTS: The average postoperative time to diagnosis of a transverse acetabular fracture was eight months. Five of the seven patients presented with a marked acute increase in pain and a new displaced transverse acetabular fracture (pelvic discontinuity) that was visible on plain radiographs. Two patients were asymptomatic but had a nondisplaced transverse acetabular fracture. In all seven patients, the trabecular metal socket appeared radiographically to be well fixed to part of the pelvis. The five patients with a displaced fracture were managed with additional surgery to stabilize the fracture. CONCLUSIONS: To our knowledge, early postoperative transverse pelvic fractures following revision of the acetabular component have not been reported previously. The most likely causes of this complication are further weakening of the remaining pelvic bone stock as a result of the reaming required to obtain a secure fit of a large-diameter hemispherical socket and the cyclic stresses on the weakened bone with resumption of walking. It is unlikely that the fractures occurred intraoperatively because in each case the socket remained well fixed to one of the pelvic fragments.

Total hip arthroplasty in patients with dwarfism.

BACKGROUND: Patients with short stature and osseous deformities resulting from osteochondrodysplasia frequently have premature development of advanced degenerative disease of the hip and thus may require total hip arthroplasty. The outcome of total hip arthroplasty in this group of young patients is unknown. In this study, we evaluated the long-term clinical and radiographic outcomes of total hip arthroplasty in patients with osteochondrodysplasia. METHODS: Between 1971 and 1997, sixty-two total hip arthroplasties were performed at our institution in thirty-seven patients with severe osteoarthritis secondary to osteochondrodysplasia. There were seventeen female patients and twenty male patients. Their average height was 142 cm, and their average age at the time of the index arthroplasty was thirty-seven years. The patients were followed clinically with use of the Harris hip score for a mean of 12.8 years, and they were followed radiographically for a mean of 11.5 years. RESULTS: The mean Harris hip score improved significantly (p < 0.0001), from 57 points preoperatively to 87 points at the time of the latest follow-up. Of the sixty hips available for follow-up, eighteen (30%) had required revision arthroplasty: fourteen required it because of aseptic loosening of one or both components; two, because of deep infection; one, because of periprosthetic fracture; and one, because of extensive osteolysis. There were two additional periprosthetic femoral fractures, which were treated with open reduction and internal fixation with retention of the components. The majority of patients had other functionally limiting conditions, such as spinal deformities, in addition to the degenerative arthritis. CONCLUSIONS: There was a high prevalence of complications, periprosthetic fractures, and mechanical failure in these patients with osteochondrodysplasia who underwent total hip arthroplasty. Young age, severe deformity, and multiple joint involvement may in part explain these findings. Nonetheless, total hip arthroplasty proved to be reliable for alleviating pain and improving function in patients with advanced symptomatic arthritis of the hip secondary to osteochondrodysplasia.

Total knee arthroplasty in young patients with juvenile rheumatoid arthritis.

BACKGROUND: Juvenile rheumatoid arthritis is a disabling and destructive condition that commonly affects the knee during childhood. Total knee arthroplasty occasionally may be necessary for the treatment of end-stage disabling arthritis of the knee in young patients. There is a paucity of available data on the results of total knee arthroplasty in adolescents. We report our experience with total knee arthroplasty in patients under the age of twenty years who had juvenile rheumatoid arthritis. MATERIALS AND METHODS: We reviewed the results of twenty-five consecutive total knee arthroplasties that had been performed at our institution between 1982 to 1997 in thirteen patients (mean age, seventeen years) with juvenile rheumatoid arthritis. The average duration of clinical follow-up was 10.7 years, and the average duration of radiographic follow-up was 6.5 years. RESULTS: The mean Knee Society pain score improved markedly from 27.6 to 88.3 points, and the mean Knee Society function score improved modestly from 14.8 to 39.2 points. There was a slight improvement in the range of motion. Symptomatic and progressive radiolucent lines were noted in two knees, one of which was revised. Two knees (one patient) required exchange of the polyethylene liner at thirteen years. There were four additional reoperations, including manipulation under general anesthesia (two knees in one patient), lysis of adhesions (one knee), and extensor mechanism realignment (one knee). CONCLUSIONS: Despite a substantial number of postoperative complications, total knee arthroplasty provided excellent relief of pain and improvement in function in this group of adolescent patients with juvenile rheumatoid arthritis.