Hip Arthroplasty Femoral Stem Designs and Their Association With Early Postoperative Periprosthetic Femoral Fractures.

BACKGROUND: Periprosthetic femoral fractures (PFFs) in total hip arthroplasty (THA), especially those in contact with the diaphyseal stem, carry high morbidity. This study evaluated how stem design influences the risk of early Vancouver B PFF or other PFF requiring operative intervention after THA. METHODS: A multicenter, retrospective study of 3,433 primary cementless THAs performed from 2014 to 2021 included 2,302 single-taper (micro M/L [n = 1,169]; M/L [n = 1,133]) and 1,131 double-taper (fit-and-fill [n = 420]; compaction-collared [n = 711]) stems. Mean follow-up was 2.2 years (range, 0.3 to 6.5 years). Primary outcomes were Vancouver B and surgically treated postoperative PFFs among differing femoral stems. Secondary outcomes included rates of intraoperative and postoperative Vancouver A and C PFFs. RESULTS: Forty five postoperative PFFs (1.3%) occurred within 8.8 weeks (median), 25 of which were Vancouver B (0.7%) and 20 total PFFs that required operative intervention (0.6%). Compaction-collared stems had a decreased risk of Vancouver B (hazard ratio 0.18, 95% confidence interval: 0.03-0.97 P = .044) and any surgically treated PFF (hazard ratio 0.10, 95% confidence interval: 0.01-0.95; P = .037). Intraoperative PFFs were most common with fit-and-fill stems (3.6%, P < .001) and Vancouver A with compaction-collared stems (1.8%, P < .001). The cohort with PFF had a higher Charlson comorbidity index (P = .004), more women (P = .001), more Dorr A or C femora (P = .013), and more posterior or lateral surgical approaches compared to those without PFF (P ≤ .001). CONCLUSION: After controlling for confounding variables, compaction-collared stems had a significantly lower risk of postoperative Vancouver B and PFF requiring operative treatment than single-taper and double-taper stems.

Two- to 4-Year Followup of a Short Stem THA Construct: Excellent Fixation, Thigh Pain a Concern.

BACKGROUND: Short stem cementless femoral components were developed to aid insertion through smaller incisions, preserve metaphyseal bone, and potentially decrease or limit the incidence of thigh pain. Despite some clinical success, the senior author (DDG) believed a higher percentage of his patients who had received a cementless short stem design were experiencing thigh pain, which, coupled with concerns about bone ingrowth fixation, motivated the review of this case series. QUESTIONS/PURPOSES: (1) What is the proportion of patients treated with a short stem cementless THA femoral component that develop thigh pain and what are the hip scores of this population? (2) What are the radiographic results, specifically with respect to bone ingrowth fixation and stress shielding, of this design? (3) Are there particular patient or procedural factors that are associated with thigh pain with this short stem design? METHODS: Two hundred sixty-one primary THAs were performed in 238 patients by one surgeon between November 2010 and August 2012. During this time period, all patients undergoing primary THA by this surgeon received the same cementless short titanium taper stem. Seven patients (eight hips) died and five patients (five hips) were lost to followup, leaving 226 patients (248 hips) with a mean followup of 3 years (range, 2-5 years). Patients rated their thigh pain during activity or rest at final followup on a 10-point visual analog scale. Harris hip scores (HHS) were obtained at every clinic appointment. Thigh pain was evaluated at the final followup or by contacting the patient by phone. Radiographs were evaluated for bone-implant fixation, bone remodeling, and osteolysis. An attempt was made to correlate thigh pain with patient demographics, implant specifications, or radiographic findings. RESULTS: Seventy-six percent of hips (180 of 238) had no thigh pain, 16% of hips (37 of 238) had mild thigh pain, and 9% (21 of 238) had moderate or severe thigh pain. Preoperatively, mean HHS was 47 (SD, 16) and at last followup, mean HHS was 88 (SD, 13). There were two femoral revisions, one for severe thigh pain and the other for infection. All but two components demonstrated bone ingrowth fixation (99%). Femoral stress shielding was mild in 64% of hips (135 of 212), moderate in 0.5% (one of 212), and severe in no hips. There is an inverse linear relationship between age and severity of thigh pain (r = -0.196; p < 0.0024). CONCLUSIONS: Although reliable fixation was achieved and good HHS were attained, the frequency and severity of thigh pain with this short cementless stem were concerning. The surgeon has subsequently abandoned this short stem design and returned to a conventional length stem. Future study direction might investigate the biomechanical grounds for the thigh pain associated with this stem design. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Cementing Constrained Liners Into Secure Cementless Shells: A Minimum 15-Year Follow-Up Study.

BACKGROUND: The authors and others have previously described the technique of cementing constrained liners into secure cementless acetabular shells and reported the short-term, average 3.9-year follow-up, using that technique. The purpose of the present study was to report the minimum 15-year follow-up of this same cohort. METHODS: Between 1988 and 2000, 31 consecutive constrained liners of one design were cemented into well-fixed, well-positioned cementless acetabular shells at 3 institutions. Average age at surgery was 72 years (range, 31-91 years). Indications for the procedure were recurrent hip dislocation in 16 cases and intraoperative instability in 15 cases. Patients were evaluated for revision for failure of the device and revision for any reason. RESULTS: At minimum 15-year follow-up, there was 1 patient lost to follow-up. Three hips (9.7%) were revised for failure of the device and 5 hips (16.1%) were revised for any reason. CONCLUSION: At minimum 15-year follow-up, considering the complexity of cases, there was excellent medium-term durability of this construct.

What Can We Learn From 20-year Followup Studies of Hip Replacement?

BACKGROUND: A patient who dies during the followup period of a study about total hip arthroplasty (THA) cannot subsequently undergo a revision. The presence of competing events (such as deaths, in a study on implant durability) violates an assumption of the commonly used Kaplan-Meier (KM) survivorship approach. In that setting, KM-based estimates of revision frequencies will be high relative to alternative approaches that account for competing events such as cumulative incidence methods. However, the degree to which this difference is clinically relevant, and the degree to which it affects different ages of patient cohorts, has been poorly characterized in orthopaedic clinical research. QUESTIONS/PURPOSES: The purpose of this study was to compare KM with cumulative incidence survivorship estimators to evaluate the degree to which the competing event of death influences the reporting of implant survivorship at long-term followup after THA in patients both younger than and older than 50 years of age. METHODS: We retrospectively reviewed 758 cemented THAs from a prospectively maintained single-surgeon registry, who were followed for a minimum of 20 years or until death. Revision rates were compared between those younger than or older than age 50 years using both KM and cumulative incidence methods. Patient survivorship was calculated using KM methods. A total of 21% (23 of 109) of the cohort who were younger than 50 years at the time of THA died during the 20-year followup period compared with 72% (467 of 649) who were older than 50 years at the time of surgery (p < 0.001). RESULTS: In the cumulative incidence analysis, 19% of the younger than age 50 years cohort underwent a revision for aseptic causes within 20 years as compared with 5% in the older than age 50 years cohort (p < 0.001). The KM method overestimated the risk of revision (23% versus 8.3%, p < 0.001), which represents a 21% and 66% relative increase for the younger than/older than age 50 years groups, respectively. CONCLUSIONS: The KM method overestimated the risk of revision compared with the cumulative incidence method, and the difference was particularly notable in the elderly cohort. Future long-term followup studies on elderly cohorts should report results using survivorship curves that take into account the competing risk of patient death. We observed a high attrition rate as a result of patient deaths, and this emphasizes a need for future studies to enroll younger patients to ensure adequate study numbers at final followup. LEVEL OF EVIDENCE: Level III, therapeutic study.

Metal-on-Metal Total Hip Arthroplasty at Five to Twelve Years Follow-Up: A Concise Follow-Up of a Previous Report.

BACKGROUND: Concern has arisen regarding potential complications with modular metal-on-metal (MoM) acetabular components in total hip arthroplasty. The purpose of this study was to analyze longitudinally the longer term results of a previously reported cohort of patients utilizing a cementless modular acetabular component with a MoM bearing. METHODS: One hundred sixty-nine consecutive but selected total hip arthroplasties were performed in 148 patients at 2 institutions using a modular acetabular MoM component. One hundred thirty-nine patients (158 hips) were living at minimum 5 years, 1 patient (1 hip) was lost to follow-up and 8 patients (10 hips) were deceased. Patients were evaluated clinically in terms of revision as well as radiographically. Additional testing (metal ion levels, advanced imaging) was performed when concerns for adverse local tissue reaction (ALTR) arose. RESULTS: There were 6 (3.8%) additional hips revised since the prior report for a total of 7 hips (4.4%) revised at 5-12 year follow-up. All newly revised hips (3.8%) demonstrated ALTR. There were 7 (4.7%) additional cases of radiographically detected acetabular osteolysis and 7 (4.7%) cases of femoral osteolysis. CONCLUSION: Longitudinal evaluation of a modular MoM bearing surface acetabular component demonstrated increased rates of ALTR and osteolysis at longer duration follow-up. Although greater than 95% of hips in this study performed well at 5-12 years, when comparing the results to metal-on-polyethylene bearings using the same acetabular component, the results were inferior. Longitudinal surveillance is warranted with this design and this bearing surface couple as cases of ALTR and osteolysis increased with longer follow-up.

Minimum 10-Year Follow-Up of Cementless Total Hip Arthroplasty Using a Contemporary Triple-Tapered Titanium Stem.

BACKGROUND: There is extensive variation in design and insertion technique of cementless tapered femoral stems. The purpose of our study was to evaluate a consecutive series of contemporary tapered cementless femoral stems inserted with a ream-and-broach technique at a minimum 10-year follow-up in patients undergoing total hip arthroplasty (THA). METHODS: One hundred consecutive THAs (88 patients) performed by a single surgeon were followed for a minimum of 10 years. Hips were evaluated clinically for revision status, Western Ontario and McMaster Universities Osteoarthritis Index, 36-item Short Form Health Survey, Harris Hip Score, and University of California, Los Angeles, and Tegner Activity Scores. Radiographic evaluation included assessment for loosening, osteolysis, and stress shielding. Kaplan-Meier survivorship analysis included end points for revision and radiographic evidence of femoral component loosening. RESULTS: At minimum 10-year follow-up, 66 patients (74 hips) were living, 20 patients (24 hips) were deceased, and 2 patients (2 hips) were lost to follow-up. Four hips required reoperation, but no femoral components were revised for aseptic loosening. One femoral component (1%) was revised due to a postoperative periprosthetic fracture. Radiographic evaluation demonstrated bone ingrowth of all stems without evidence of component loosening and 1 case of severe stress shielding. Kaplan-Meier survivorship at 10 years was 100% for the end points of femoral revision for loosening or femoral radiographic loosening. CONCLUSION: This contemporary, cementless titanium-tapered femoral component inserted with ream-and-broach technique demonstrated excellent results in terms of outcomes and clinical durability as well as osteointegration on radiographs at minimum 10-year follow-up. This study corroborates, with level 2 and level 3 data, level 1 data reported in national registries.

Patient-Reported Allergies Predict Worse Outcomes After Hip and Knee Arthroplasty: Results From a Prospective Cohort Study.

BACKGROUND: Retrospective analyses have demonstrated correlation between patient-reported allergies and negative outcomes after total joint arthroplasty. We sought to validate these observations in a prospective cohort. METHODS: One hundred forty-four patients undergoing total hip arthroplasty and 302 patients undergoing total knee arthroplasty were prospectively enrolled. Preoperatively, patients listed their allergies and completed the Medical Outcomes Study Short Form 36 (SF-36) and the Charlson Comorbidity Index (CCI) Questionnaire. At a mean of 17 months (range 12-25 months) postoperatively, SF-36, CCI, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were obtained by telephone survey. Regression analysis was used to determine the strength of correlation between patient age, comorbidity burden, and number of allergies and outcome measurements. RESULTS: In 446 patients, 273 reported at least 1 allergy. The number of allergies reported ranged from 0 to 33. Penicillin or its derivative was the most frequently reported allergy followed by sulfa, environmental allergen, and narcotic pain medication. Patients reporting at least 1 allergy had a significantly lower postoperative SF-36 Physical Component Score compared to those reporting no allergies (51.3 vs 49.4, P = .01). The SF-36 postoperative Mental Component Score was no different between groups. Multivariate regression analysis showed that age and patient reported allergies, but not comorbidities, were independently associated with worse postoperative SF-36 Physical Component Summary (PCS) and WOMAC score. Patients with allergies experienced the same improvement in SF-36 PCS as those without an allergy. Comorbidities did not correlate with patient-reported function postoperatively. CONCLUSION: Patients who report allergies have lower postoperative outcome scores but may experience the same increment in improvement after total joint arthroplasty.

What can be learned from minimum 20-year followup studies of knee arthroplasty?

BACKGROUND: Long-term evaluation of knee arthroplasty should provide relevant information concerning the durability and performance of the implant and the procedure. Because most arthroplasties are performed in older patients, most long-term followup studies have been performed in elderly cohorts and have had low patient survivorship to final followup; the degree to which attrition from patient deaths over time in these studies might influence their results has been poorly characterized. QUESTIONS/PURPOSES: The purpose of this study was to examine the results at 20-year followup of two prospectively followed knee arthroplasty cohorts to determine the following: (1) Are there relevant differences among the two implant cohorts in terms of revision for aseptic causes (osteolysis, or loosening)? (2) How does patient death over the long followup interval influence the comparison, and do the comparisons remain valid despite the high attrition rates? METHODS: Two knee arthroplasty cohorts from a single orthopaedic practice were evaluated: a modular tibial tray (101 knees) and a rotating platform (119 knees) design. All patients were followed for a minimum of 20 years or until death (mean, 14.1 years; SD 5.0 years). Average age at surgery for both cohorts was >70 years. The indications for the two cohorts were identical (functionally limiting knee pain) and was surgeon-specific (each surgeon performed all surgeries in that cohort). Revision rates through a competing risks analysis for implants and survivorship curves for patients were evaluated. RESULTS: Both of these elderly cohorts showed excellent implant survivorship at 20 years followup with only small differences in revision rates (6% revision versus 0% revision for the modular tibial tray and rotating platform, respectively). However, attrition from patient deaths was substantial and overall patient survivorship to 20-year followup was only 26%. Patient survivorship was significantly higher in patients<65 years of age in both cohorts (54% versus 15%, p<0.001 modular tray cohort, and 52% versus 26%, p=0.002 rotating platform cohort). Furthermore, in the modular tray cohort, patients<65 years had significantly higher revision rates (15% versus 3%, p=0.0019). CONCLUSIONS: These two cohorts demonstrate the durability of knee arthroplasty in older patients (the vast majority older than 65 years). Unfortunately, few patients lived to 20-year followup, thus introducing bias into the analysis. These data may be useful as a reference for the design of future prospective studies, and consideration should be given to enrolling younger patients to have robust numbers of living patients at long-term followup. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Fixation and Wear With Contemporary Acetabular Components and Cross-Linked Polyethylene at 10-Years in Patients Aged 50 and Under.

We evaluated the mid-term performance of a moderately cross-linked polyethylene THA bearing in younger patients. One hundred consecutive THAs performed in patients 50 years of age and under using the same cementless acetabular component and moderately cross-linked polyethylene were evaluated at minimum 10 year follow-up. At final follow-up 75 patients (89 hips) were living, 7 patients (7 hips) were deceased and 4 patients (4 hips) were lost to follow-up. Average Tegner and UCLA scores were 3.7 and 5.8, respectively. Average steps per year were 1.84 million. The average linear wear rate was 0.05 mm/y and steady state wear rate was 0.033 mm/y. There was no detectable osteolysis. Minimum 10 year follow-up demonstrated durable fixation and reduced wear (P<0.001) when compared to our historical controls.

Patient reported allergies are a risk factor for poor outcomes in total hip and knee arthroplasty.

We evaluated 459 patients undergoing THA or TKA who completed preoperative and postoperative WOMAC and/or SF36 surveys. Medical comorbidities and reported allergies were also recorded. Evaluation of surveys was compared for patients with or without 4 or more reported allergies using statistical methods. Patients with 4 or more reported allergies had less improvement on SF36 Physical Component Score (∆PCS=4.2) than those with 0-3 allergies (∆PCS=10.0, P=0.0002). Regression analysis showed that this change was independent of self-reported comorbidities. Patients reporting 4 or more allergies also had less improvement in WOMAC function (∆F=21.4) than those with 0-3 allergies (∆F = 27.2, P=0.036). Similar nonsignificant trends occurred in SF36 mental and WOMAC pain and stiffness scores.

Minimum 20-year follow-up results of revision total hip arthroplasty with improved cementing technique.

A consecutive, non-selective cohort of 83 (77 patients) cemented total hip arthroplasty revisions using contemporary cementing techniques was analyzed at a minimum of 20 years following the index procedure. No patients were lost to follow-up. The average age at revision was 62.4 years (23 to 89). Twenty-two hips (26.5%) had had a reoperation, eighteen (21.7%) for aseptic loosening, 3 (3.6%) for femoral prosthesis fracture and 1 (1.2%) for dislocation. The incidence of re-revision for aseptic femoral loosening was 7.5% and for aseptic acetabular loosening was 21.7%. These results confirm that cemented femoral revision using improved cementing techniques is a durable option in revision hip surgery. In contrast to this, THA revisions using a cemented acetabular component have been less durable at this length of follow-up.

Fixation and wear with a contemporary acetabular component and cross-linked polyethylene at minimum 10-year follow-up.

UNLABELLED: Long term total hip arthroplasty follow-up has demonstrated bearing surface wear and failure of fixation as the major modes of failure. The purpose of this study was to evaluate the minimum 10year results of a third generation cementless acetabular component using moderately cross-linked polyethylene liners. 150 primary THAs were evaluated clinically for need for revision and activity evaluated using accelerometers, WOMAC, Tegner and UCLA activity-level scores. Radiographs were evaluated for wear, osteolysis and loosening. We compared this cohort to three of our previously reported cohorts. The only revision was unrelated to liner wear and all acetabular components were bone ingrown. There were no cases of acetabular osteolysis and one case of femoral osteolysis. Average steps per year were 1.59 million. Mean steady state wear rate averaged 0.04mm/year. At 10-years, excellent fixation and low wear were demonstrated using a cementless acetabular construct and moderately cross-linked polyethylene liner. LEVEL OF EVIDENCE: Therapeutic study, Level III (retrospective comparative study-prospective cohort with historical control).

Femoral remodeling around Charnley total hip arthroplasty is unpredictable.

BACKGROUND: There are two unusual remodeling patterns of the proximal femur around well-fixed Charnley total hip arthroplasties: cortical thinning leading to endosteal widening around the femoral component and hypertrophy of the distal femoral cortex. Previous studies have shown remodeling patterns are affected by stem design and occur early postoperatively. It is unclear if these changes are related to patient demographics or if they progress throughout the lifetime of the implant. QUESTIONS/PURPOSES: We determined if patient demographic variables influence remodeling patterns after cemented Charnley total hip arthroplasty and if the observed remodeling changes persist long-term. METHODS: We retrospectively reviewed the radiographs of 106 well-fixed Charnley femoral components. Using a novel digital edge detection program, we determined the femoral remodeling pattern and time-related changes in femoral dimensions. The minimum followup was 20 years (mean, 25.3 years; range, 19.5-37 years). RESULTS: We found no association between remodeling type and age at surgery, sex, preoperative diagnosis, body mass index, or postoperative activity level. There was also no association between initial implant alignment and remodeling type. Cortical thickening in the distal hypertrophy group was an early phenomenon occurring primarily within the first 2 years, whereas cortical thinning begins later and is a more progressive process. CONCLUSIONS: These data show remodeling after cemented Charnley total hip arthroplasty is not related to patient demographic variables; however, distal cortical hypertrophy can be predicted in the early postoperative period.

Durability of a cruciate-retaining TKA with modular tibial trays at 20 years.

BACKGROUND: Modular tibial trays have been utilized in TKA for more than 20 years. However, concerns have been raised about modular implants and it is unclear whether these devices are durable in the long term. QUESTIONS/PURPOSES: We determined (1) survival, (2) relationship of age and polyethylene thickness with revision, (3) function, and (4) radiographic lucencies and osteolysis in patients having a single TKA implant at 20-year followup. METHODS: We prospectively followed 75 patients implanted with 101 Press-Fit Condylar(®) (Johnson and Johnson Professional, Inc, Raynham, MA, USA) posterior cruciate-retaining TKAs (with modular tibial trays) between 1988 and 1991. At 20 years, 59 patients were deceased. We clinically evaluated the living 16 patients (22 knees) and contacted the relatives of all deceased patients to confirm implant status. We clinically assessed 14 of the 16 patients with the Knee Society score, WOMAC, and UCLA and Tegner activity level scores. Radiographically, we determined lucencies, component migration, and osteolysis. We performed survival analysis including all original patients. Minimum followup was 20 years (mean, 20.6 years; range, 20-21.8 years). RESULTS: Six reoperations were performed in five patients (6% rate of revision) over the 20-year followup. All revisions were related to polyethylene wear and occurred at least 10 years after the primary procedure. Survivorship with revision for any reason as the end point was 91% (95% CI, 0.83-0.97) at 20 years. Average Knee Society clinical and functional scores were 90 (range, 60-100) and 59 (range, 30-87), respectively. CONCLUSIONS: Our data demonstrate the durability of this posterior cruciate-retaining TKA design. The data provide a standard for newer designs and newer bearing surface materials at comparable followup.

Metal on metal total hip arthroplasty using modular acetabular shells.

Metal on metal bearings were reintroduced into the United States for use in total hip arthroplasty approximately a decade ago. We evaluated a consecutive series cohort of 148 patients with 169 hips who underwent THR using a metal on metal bearing surface with a modular acetabular shell that had fixation augmentation with dome screws. At 3 to 8 year follow-up, average 4.7 years, only one component was revised (for femoral loosening). 3 hips demonstrated proximal femoral osteolysis and 3 hips demonstrated pelvic osteolysis. The average follow-up Harris Hip Score was 94 (range, 57-100). Although the results have been excellent, we continue to closely monitor these hips for any long term failures, or concerns.

Cementless acetabular fixation in patients 50 years and younger at 10 to 18 years of follow-up.

The purpose of the study was to evaluate the 10- to 18-year follow-up of cementless acetabular fixation in patients 50 years and younger. We retrospectively reviewed a consecutive group of 118 patients (144 hips) in whom primary total hip arthroplasty had been performed by 2 surgeons using a cementless acetabular component. Two (1.4%) cementless acetabular components were revised because of aseptic loosening. Twenty-four hips (16.7%) were revised for any mechanical failure of the acetabular component mostly related to acetabular liner wear and osteolysis. The average linear wear rate was 0.19 mm per year, which was higher than our previous reports with cemented acetabular fixation. The fiber mesh ingrowth surface of the cementless acetabular component in this study was superior to cemented acetabular components in terms of fixation. However, the high rates of wear and osteolysis have led to poor overall acetabular component construct survivorship.

Liner exchange and bone grafting: rare option to treat wear & lysis of stable TKAs.

BACKGROUND: Liner exchange and bone grafting are commonly performed for wear and osteolysis around well-fixed modular acetabular components that otherwise would require structural allografting and revision THA. However, liner exchange in the face of substantial lysis around TKA has been performed rarely with reports of failure rates of up to 25% at 3 year followup. QUESTIONS/PURPOSES: We therefore evaluated the technique of liner exchange and bone grafting for cases of wear and extensive osteolysis around TKAs in which the components were well-fixed and well-aligned to determine (1) rerevision rates; (2) fate of the bone graft; (3) radiographic loosening rates; and (4) functional scores. METHODS: We retrospectively reviewed 22 patients (25 knees) who underwent revision TKA with exchange of the modular polyethylene insert and bone grafting in cases with well-fixed components and large areas of osteolysis (up to 54 cm(2) on a single projection) at the time of revision. The average area of osteolysis was 21 cm(2) and 10 cm(2) on the AP projection of the femur and tibia, respectively. On the lateral projection, the average area of osteolysis for the femur and tibia was 22 cm(2) and 9.3 cm(2). Minimum clinical and radiographic followup was 22 and 22 months (average, 61 and 59; range, 22-142 and 22-130, respectively). RESULTS: One of the 25 knees was revised for aseptic loosening or recurrence of osteolysis. On radiographs, 84.6% and 70% of femoral and tibial osteolytic lesions, respectively, showed evidence of complete or near complete graft incorporation. The remaining lesions showed evidence of partial graft incorporation with the exception of one tibial lesion, which was in the revised case. All other components were well fixed with no evidence of radiographic loosening. CONCLUSIONS: In this selected series of cases with extensive osteolysis around well-fixed and well-aligned TKAs, liner exchange and bone grafting provided durable midterm results with extensive graft incorporation. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Routine surveillance of modular PFC TKA shows increasing failures after 10 years.

BACKGROUND/RATIONALE: A 10-year survivorship of 100% was reported for patients with PFC cruciate-retaining prostheses. Beyond 10 years, we observed additional polyethylene wear likely related to thin liners gamma-irradiated in air and were concerned this wear might predispose to implant construct failure. QUESTIONS/PURPOSES: We therefore determined (1) the functional scores at a minimum of 15 years followup, (2) rates of radiographic failure, (3) overall revision rates, and (4) mode of failure after 10 years and the fate of the revised implants. METHODS: We retrospectively reviewed 75 patients with 101 press-fit condylar posterior cruciate-retaining prostheses. At a minimum followup of 15 years, 35 patients (47 knees) were living and evaluated clinically. No patients were lost to followup. RESULTS: There were no revisions during the first 11 years and six reoperations subsequently were performed in five patients (6% overall rate of revision but 12.8% in patients who survived more than 15 years). Three of six revisions had concerning liner wear at 10 years and all six were revised for polyethylene wear. Polyethylene exchange was performed in four of the five patients who underwent revisions, all of whom were doing well at an average of 7.2 years (range, 4.7-9.1 years) after the revision procedure. CONCLUSIONS: At long-term followup, the overall revision rate remained low (6%). For patients surviving 15 years or more, the rate of revision was 12.8% and all revisions were secondary to aseptic sequelae of polyethylene wear. All revisions occurred more than 10 years after the initial procedures. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Total hip arthroplasty with a cemented, polished, collared femoral stem and a cementless acetabular component. A follow-up study at a minimum of ten years.

BACKGROUND: Recent studies have suggested that cemented femoral components with a polished surface may provide superior long-term fixation when compared with femoral components with a roughened surface. The purpose of this study was to evaluate the results of total hip arthroplasty with a cemented femoral component with a polished surface finish and compare them with the results of total hip arthroplasty performed with a similar design of cemented femoral component with a rougher surface finish. METHODS: We retrospectively reviewed a consecutive group of 132 patients (149 hips) in whom primary total hip arthroplasty had been performed by one surgeon using a cemented collared femoral component with a polished (0.1-microm Ra) surface finish and a cementless acetabular component. Ninety-eight patients (115 hips) were followed for a minimum of ten years. We compared the survivorship of this prosthesis with that of a femoral component of similar design but with rougher surfaces (matte or grit-blasted). RESULTS: No polished stems were revised because of aseptic loosening or demonstrated radiographic evidence of loosening; however, eight hips (5.4%) with a polished stem demonstrated osteolysis distal to the greater or lesser tro-chanter. In contrast, six stems (2.0%) with a matte surface finish of 0.8-microm Ra were revised because of aseptic loosening, and an additional five stems were seen to be loose radiographically. Eleven stems (9.2%) with a grit-blasted surface finish of 2.1-microm Ra were revised because of aseptic loosening, and an additional four stems were seen to be loose radiographically. The difference in the prevalence of revision due to aseptic loosening between the group with the 0.1-microm Ra surface and the group with the 2.1-microm Ra surface was significant (p = 0.001), as was the difference between the prevalence of revision due to aseptic loosening between the group with the 0.8-microm Ra surface and the group with the 2.1-microm Ra surface (p = 0.001). No cups were revised because of aseptic loosening, and one hip had radiographic signs of acetabular loosening. CONCLUSIONS: This study demonstrated excellent durability of a prosthesis consisting of a cemented, collared, polished femoral component and a cementless acetabular component. While no hips were revised because of aseptic loosening, distal femoral osteolysis was observed in eight hips (5.4%), a higher prevalence than has been reported by others after similar durations of follow-up of tapered, collarless, polished femoral components.