A Comparison of Risk of Dislocation and Cause-Specific Revision Between Direct Anterior and Posterior Approach Following Elective Cementless Total Hip Arthroplasty

BackgroundUse of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased over the last decade. We sought to investigate whether (1) a difference exists in dislocation risk for DAA compared with posterior THA, (2) a difference exists in risk for specific revision reasons, and (3) the likelihood of adverse 90-day postoperative events differs.MethodsWe conducted a cohort study using data from Kaiser Permanente’s Total Joint Replacement Registry. Patients aged ≥18 years who underwent primary cementless THA for osteoarthritis with a highly cross-linked polyethylene liner were included (2009-2017). Multivariable Cox proportional hazards regression was used to evaluate dislocation and cause-specific revision risks, and multivariable logistic regression was used to evaluate 90-day emergency department visits, 90-day unplanned readmissions, and 90-day complications (including deep infection, deep vein thrombosis, and pulmonary embolism).ResultsOf 38,399 primary THA, 6428 (16.7%) were DAA. All-cause revision at 2-years follow-up was 1.78% (95% confidence interval [CI] = 1.46-2.17) for DAA and 2.28% (95% CI = 2.11-2.45) for posterior. After adjusting for covariates, DAA had a lower risk of dislocation (hazard ratio [HR] = 0.39, 95% CI = 0.29-0.53), revision for instability (HR = 0.33, 95% CI = 0.18-0.58), revision for periprosthetic fracture (HR = 0.57, 95% CI = 0.34-0.96), and readmission (odds ratio = 0.82, 95% CI = 0.67-0.99) compared with posterior approach but a higher risk of revision for aseptic loosening (HR = 2.26, 95% CI = 1.35-3.79).ConclusionWhile the DAA associated with lower risks of dislocation and revision for instability and periprosthetic fracture, it is associated with a higher revision risk for aseptic loosening. Surgeons should discuss these risks with their patients.     

Cause-Specific Stem Revision Risk in Primary Total Hip Arthroplasty Using Cemented vs Cementless Femoral Stem Fixation in a US Cohort

BackgroundWe sought to evaluate the cause-specific revision risk following hybrid (cemented stem mated to a cementless acetabular implant) vs cementless total hip arthroplasty (THA) in a US cohort.MethodsPrimary elective THA for osteoarthritis was identified using Kaiser Permanente’s Total Joint Replacement Registry (2001-2018). Multivariable Cox regression was used to evaluate cause-specific revision, including aseptic loosening, infection, instability, and periprosthetic fracture (PPF), for hybrid vs cementless THA. Analysis was stratified by age (<65, 65-74, and ≥75 years) and gender.ResultsThe study cohort comprised 88,830 THAs, including 4539 (5.1%) hybrid THAs. In stratified analysis, hybrid THA had a higher revision risk for loosening in females in all 3 age subgroups. A lower risk of revision for PPF was observed following hybrid THA in females aged ≥75 years. For females ≥75 years, cementless THA had an excess PPF risk of 0.9% while hybrid THA had an excess loosening risk of 0.2%, translating to a theoretical prevention of 10 PPF revisions but a price of 3 loosening revisions per 1000 hybrid THAs. No difference in revision risk was observed in males.ConclusionWe observed differences in cause-specific revision risks by method of stem fixation which depended upon patient age and gender. Although the trend toward all cementless fixation continue, there may be a role for hybrid fixation in females ≥75 years to mitigate risk for revision due to PPF at the potential cost of a slight increase in longer term aseptic loosening.Level of EvidenceLevel III.     

The Association of Race/Ethnicity and Total Knee Arthroplasty Outcomes in a Universally Insured Population

BackgroundPrior studies have documented racial/ethnic disparities in the United States for total knee arthroplasty (TKA) outcomes. One factor cited as a potential mediator is unequal access to care. We sought to assess whether racial/ethnic disparities persist in a universally insured TKA population.MethodsA US integrated health system’s total joint replacement registry was used to identify elective primary TKA (2000-2016). Racial/ethnic differences in revision and 90-day postoperative events (readmission, emergency department [ED] visit, infection, venous thromboembolism, and mortality) were analyzed using Cox proportional hazard and logistic regression with adjustment for confounders.ResultsOf 129,402 TKA, 68.8% were white, 16.2% were Hispanic, 8.4% were black, and 6.6% were Asian. Compared to white patients, Hispanic patients had lower risks of septic revision (hazard ratio [HR] = 0.69, 95% confidence interval [CI] = 0.57-0.83) and infection (odds ratio [OR] = 0.42, 95% CI = 0.30-0.59), but a higher likelihood of ED visit (OR = 1.28, 95% CI = 1.22-1.34). Black patients had higher risks of aseptic revision (HR = 1.61, 95% CI = 1.42-1.83), readmission (OR = 1.13, 95% CI = 1.02-1.24), and ED visit (OR = 1.31, 95% CI = 1.23-1.39). Asian patients had lower risks of aseptic revision (HR = 0.67, 95% CI = 0.54-0.83), septic revision (HR = 0.78, 95% CI = 0.60-0.99), readmission (OR = 0.89, 95% CI = 0.79-1.00), and venous thromboembolism (OR = 0.59, 95% CI = 0.45-0.78).ConclusionWe observed differences in TKA outcome, even within a universally insured population. While lower risks in some outcomes were observed for Asian and Hispanic patients, the higher risks of aseptic revision and readmission for black patients and ED visit for black and Hispanic patients warrant further research to determine reasons for these findings to mitigate disparities.Level of EvidenceLevel III.     

Single Wedge Femoral Stem Designs are Associated With a Higher Risk for Revision After Cementless Primary Total Hip Arthroplasty

BackgroundCementless total hip arthroplasty (THA) femoral stems are the most commonly selected prostheses in the United States. Optimal stem geometry remains controversial with excellent survivorship reported for many designs. We compared cause-specific stem revision of single-wedge versus double-wedge designs from a multicenter US cohort.MethodsData from an integrated healthcare network’s total joint replacement registry were used to conduct a cohort study. Primary elective cementless THAs were identified (2001 to 2018). Implant exposure groups were classified by design geometry using the system proposed by Khanuja et al. Type 1 single-wedge (n = 11,082) and type 2 double-wedge (n = 32,380) designs were compared, and other design types were excluded; the final study cohort comprised 43,462 THAs. Cause-specific multivariable Cox regressions were used to evaluate risk for revision due to infection or aseptic reasons, including loosening, instability, periprosthetic fracture, or other reasons.ResultsAfter adjustment for covariates, a higher aseptic revision risk was observed for type 1 when compared to type 2 designs (hazard ratio = 1.91, 95% confidence interval = 1.33-2.75). When looking at specific revision reasons, revision for aseptic loosening (hazard ratio = 3.46, 95% confidence interval = 2.24-5.34) was higher for type 1 versus type 2 designs. No differences were found for septic revision, instability, periprosthetic fracture, or revisions for other reasons.ConclusionsType 1 single-wedge designs were found to have a higher risk of revision due to aseptic loosening relative to type 2 double-wedge designs. Femoral stem geometry should be considered when selecting a cementless femoral implant.Level of EvidenceLevel III.     

High Rate of Re-Revision in Patients Less Than 55 Years of Age Undergoing Aseptic Revision Total Knee Arthroplasty

BackgroundThere are limited data on the outcomes of revision total knee arthroplasty in young patients. We sought to characterize the re-revision-free survival and risk factors for re-revision in patients less than 55 years who underwent aseptic revision TKA.MethodsWe retrospectively reviewed 197 revision TKAs at a mean follow-up of 5 years. Mean age was 49 years; mean body mass index was 31 kg/m². Twenty-seven (14%) patients had at least 1 prior revision TKA. The most common indications for revision included instability (29%), arthrofibrosis (26%), and aseptic loosening (24%). Constraint included the following: 59 posterior-stabilized (30%), 123 varus-valgus constrained (62%), and 15 hinged (8%). Components revised included the following: 93 femur/tibia (47%), 68 polyethylene-only (35%), 19 femur-only (10%), and 17 other (9%). Survivorship free from re-revision was calculated via the Kaplan-Meier method and a multivariate Cox proportional regression was utilized to identify risk factors for re-revision.ResultsSurvivorship free from any re-revision at 5 years was 80%. In the multivariate analysis, patients with a prior revision (hazard ratio [HR] = 2.78, P = .02), an isolated polyethylene exchange (HR = 3.0, P = .004), and a hinged prosthesis (HR = 3.47, P = .05) were significant risk factors for lower revision-free survival. Forty-two patients (21%) underwent re-revision, most commonly for periprosthetic joint infection (7%), instability (6%), and aseptic loosening (5%). Re-revision occurred in 18/68 (26%) patients undergoing an isolated polyethylene exchange.ConclusionPatients less than 55 years undergoing revision TKA have a modest 5-year revision-free survival of 80%. Patients with prior revision TKAs (HR = 2.78), hinge type prostheses (HR = 3.47), and polyethylene-only revisions (HR = 3.0) had higher revision rates.     

A Comparison of Revision Rates for Dislocation and Aseptic Causes Between Dual Mobility and Large Femoral Head Bearings in Primary Total Hip Arthroplasty With Subanalysis by Acetabular Component Size: An Analysis of 106,163 Primary Total Hip Arthroplasties

BackgroundDual mobility (DM) and large femoral head bearings (≥36 mm) both decrease the risk of dislocation in total hip arthroplasty (THA). There is limited comparable data in primary THA. This study compared the revision rates for dislocation and aseptic causes between DM and large femoral heads and subanalyzed by acetabular component size.MethodsData from the Australian Orthopedic Association National Joint Replacement Registry were analyzed for patients undergoing primary THA for osteoarthritis from January 2008 (the year of first recorded DM use) to December 2019. All DM and large femoral head bearings were identified. The primary outcome measure was the cumulative percent revision (CPR) for dislocation and for all aseptic causes. The results were adjusted by age, sex, and femoral fixation. A subanalysis was performed stratifying acetabular component diameter <58 m and ≥58 mm.ResultsThere were 4942 DM and 101,221 large femoral head bearings recorded. There was no difference in the CPR for dislocation (HR = 0.69 (95% CI 0.42, 1.13), P = .138) or aseptic causes (HR = 0.91 (95% CI 0.70, 1.18), P = .457). When stratified by acetabular component size, DM reduced the CPR for dislocation in acetabular component diameter <58 mm (HR = 0.55 (95% CI 0.30, 1.00), P = .049). There was no difference for diameter ≥58 mm. There was no difference in aseptic revision when stratified by acetabular component diameter.ConclusionThere is no difference in revision rates for dislocation or aseptic causes between DM and large femoral heads in primary THA. When stratified by acetabular component size, DM reduces dislocation for acetabular component diameter <58 mm.Level of EvidenceLevel III.     

Disparities in Elective and Nonelective Total Hip Arthroplasty

BackgroundPrior studies have shown disparities in utilization of primary and revision total hip arthroplasty (THA). However, little is known about patient population differences associated with elective and nonelective surgery. Therefore, the aim of this study was to explore factors that influence primary utilization and revision risk of THA based on surgery indication.MethodsData were obtained from 7,543 patients who had a primary THA from 2014 to 2020 in a database, which consists of multiple health partner systems in Louisiana and Texas. Of these patients, 602 patients (8%) underwent nonelective THA. THA was classified as “elective” or “nonelective” if the patient had a diagnosis of hip osteoarthritis or femoral neck fracture, respectively.ResultsAfter multivariable logistic regression, nonelective THA was associated with alcohol dependence, lower body mass index (BMI), women, and increased age and number of comorbid conditions. No racial or ethnic differences were observed for the utilization of primary THA. Of the 262 patients who underwent revision surgery, patients who underwent THA for nonelective etiologies had an increased odds of revision within 3 years of primary THA (odds ratio (OR) = 1.66, 95% Confidence Interval (CI) = 1.06-2.58, P-value = .025). After multivariable logistic regression, patients who had tobacco usage (adjusted odds ratio (aOR) = 1.36, 95% CI = 1.04-1.78, P-value = .024), alcohol dependence (aOR = 2.46, 95% CI = 1.45-4.15, P-value = .001), and public insurance (OR = 2.08, 95% CI = 1.18-3.70, P-value = .026) had an increased risk of reoperation.ConclusionDemographic and social factors impact the utilization of elective and nonelective primary THA and subsequent revision surgery. Orthopaedic surgeons should focus on preoperative counseling for tobacco and alcohol cessation as these are modifiable risk factors to directly decrease reoperation risk.     

Survivorship and Risk Factors for Re-Revision after Aseptic Revision Total Hip Arthroplasty in Patients Aged ≤55 Years

BackgroundThere is a relative paucity of literature on the outcomes after revision total hip arthroplasty (rTHA) in young patients. This study reports the survivorship and risk factors for re-revision in patients aged ≤55 years.MethodsWe identified 354 patients undergoing aseptic nononcologic rTHA at mean follow-up of 5 years after revision, with mean age of 48 years, body mass index of 28 kg/m², and 64% female. Thirty-five (10%) patients underwent at least 1 previous rTHA. The main indications for rTHA included wear/osteolysis (21%), adverse local tissue reaction (21%), recurrent instability (20%), acetabular loosening (16%), and femoral loosening (7%); and included acetabular component-only rTHA in 149 patients (42%), femoral component-only rTHA in 46 patients (13%), both component rTHA in 44 patients (12%), and head/liner exchanges in patients 115 (33%). The Kaplan-Meier method was used to measure survivorship free from re-revision THA, and multivariate regression was used to identify risk factors for re-revision THA.ResultsSixty-two patients (18%) underwent re-revision THA at the mean time of 2.5 years, most commonly for instability (37%), aseptic loosening (27%), and prosthetic joint infection (15%). The rTHA survivorship from all-cause re-revision and reoperation was 83% and 79% at 5 years, respectively. Multivariate analysis demonstrated that patients undergoing femoral component only (hazard ratio 4.8, P = .014) and head/liner exchange rTHA (hazard ratio 2.5, P = .022) as risk factors for re-revision THA.ConclusionAbout 1 in 5 patients aged ≤55 years undergoing rTHA required re-revision THA at 5 years, most commonly for instability. The highest risk group included patients undergoing head/liner exchanges and isolated femoral component revisions.     

Total hip arthroplasty for rheumatoid arthritis in younger patients: 2,557 replacements in the Finnish Arthroplasty Register followed for 0–24 years

Background?The results of total hip arthroplasty (THA) in young patients with rheumatoid arthritis (RA) have been reported in only a few studies. On a nationwide level, the outcome of THA in these patients is unknown. We evaluated the population-based survival of THA in patients under 55 years of age with RA and factors affecting the survival.

Patients?Between 1980 and 2003, 2,557 primary THAs performed for RA in patients less than 55 years of age were reported to the Finnish Arthroplasty Register.

Results?Proximally circumferentially porous-coated uncemented stems had a 15-year survival rate of 89% (95% CI 83–94) with aseptic loosening as endpoint. The risk of stem revision due to aseptic loosening was higher with cemented stems than with proximally porouscoated uncemented stems implanted during the same period (RR 2.4; p < 0.001). In contrast, Cox regression analysis showed that the risk of cup revision was significantly higher for all uncemented cup concepts than for all-polyethylene cemented cups with any cup revision as endpoint. There were no significant differences in survival between the THR concepts.

Interpretations?Uncemented proximally circumferentially porous-coated stems and cemented all-poly-ethylene cups are currently the implants of choice for young patients with RA.     

Extended Oral Antibiotic Prophylaxis After Aseptic Revision Total Hip Arthroplasty: Does It Decrease Infection Risk?

BackgroundExtended oral antibiotic prophylaxis (EOA) has been shown to reduce infection after high-risk primary total hip arthroplasties (THAs) and reimplantations. However, data are limited regarding EOA after aseptic revision THAs. This study evaluated the impact of EOA on infection-related outcomes after aseptic revision THAs.MethodsWe retrospectively identified 1,107 aseptic revision THAs performed between 2014 and 2019. Patients who received EOA >24 hours perioperatively (n = 370) were compared to those who did not (n = 737) using an inverse probability of treatment weighting model. Their mean age was 65 years (range, 19-98 years), mean body mass index was 30 kg/m² (range, 16-72), and 54% were women. Outcomes included cumulative probabilities of any infection, periprosthetic joint infection (PJI), and re-revision or reoperation for infection. Mean follow-up was 4 years (range, 2-8 years).ResultsThe cumulative probability of any infection after aseptic revision THA was 2.3% at 90 days, 2.7% at 1 year, and 3.5% at 5 years. The cumulative probability of PJI was 1.7% at 90 days, 2.1% at 1 year, and 2.8% at 5 years. There was a trend toward an increased risk of any infection (hazards ratio [HR] = 2.6; P = .058), PJI (HR = 2.6; P = .085), and re-revision (HR = 6.5; P = .077) or reoperation (HR = 2.3; P = .095) for infection in patients who did not have EOA at the final clinical follow-up.ConclusionsEOA after aseptic revision THA was not associated with a statistically significant decreased risk of any infection, PJI, or re-revision or reoperation for infection at all time points.Level of EvidenceLevel III.     

Etiology and Complications of Early Aseptic Revision Total Hip Arthroplasty Within 90 Days

BackgroundThe etiology, complications, and rerevision risks of early aseptic revision total hip arthroplasty (THA) within 90 days are insufficiently documented.MethodsA national insurance claims database (PearlDiver Technologies, Fort Wayne, IN) was queried for patients who underwent unilateral aseptic revision THA within 90 days of the index procedure using administrative codes. Patients who underwent revision for infection, without minimum 2-year follow-up, and younger than 18 years were excluded. This cohort was matched based on gender, age, and Charlson Comorbidity Index to a control group of patients who underwent primary THA without revision within 90 days. Two-year rerevision and 90-day complication rates were recorded. Chi-square and Fisher exact tests were used as appropriate for statistical comparison.ResultsFour hundred two patients met the inclusion criteria for early aseptic revision within 90 days of the index procedure and were matched to the control group. The overall 2-year rerevision rate was higher in the early revision group compared with control group (14.9% vs 2.5%, P < .001). Complications within 90 days occurred more frequently in the early revision group, including blood transfusion (10.2% vs 3.2%, P < .001), deep vein thrombosis (9.0% vs 3.2%, P = .001), and pulmonary embolism (2.74% vs 0.75%, P = .031). The most common reasons for early aseptic revision were dislocation (41.5%), fracture (38.1%), and loosening (17.4%).ConclusionEarly aseptic revision THA is associated with significantly higher 90-day complication rates and 2-year rerevision rates compared with a control group of primary THA without revision. The most common reasons for acute early revision were dislocation, fracture, and mechanical loosening.Level of EvidenceLevel III.     

Increased Synovial Inflammatory Markers in Aseptic Total Hip Arthroplasty Dislocation

BackgroundIn cases of total hip arthroplasty (THA) dislocation, a synovial fluid aspiration is often performed to evaluate for periprosthetic joint infection (PJI). It is currently unclear how aseptic dislocation of a THA influences synovial fluid white blood cell (WBC) count and polymorphonuclear percentage (PMN%). The primary aim of this study is to investigate the influence of THA dislocation on synovial WBC count and PMN%.MethodsTwenty-eight patients who underwent a synovial aspiration of a THA between 2014 and 2019 were identified and enrolled in our case-control study. Patients with an aseptic THA dislocation and synovial hip aspiration were matched against patients without dislocation, patients undergoing hip aspiration before aseptic THA revision surgery, and patients undergoing hip aspiration before septic THA revision surgery.ResultsSynovial WBC count was significantly increased in the dislocation vs aseptic THA revision group (P = .015), as well as between the septic revision group vs dislocation and aseptic THA revision group (both P < .001). The PMN% did not differ significantly between the dislocation and aseptic revision groups (P = .294). Mean C-reactive protein values were 12.4 ± 14.9 mg/dL in THA dislocation, 24.1 ± 37.7 mg/dL in THA without infection compared to 85.7 ± 84.9 mg/dL in THA infection group (P < .001).ConclusionThis study shows that THA dislocation has a significant impact on synovial WBC count in joint aspiration. Our data suggest that in the setting of THA dislocation, synovial WBC and PMN% may not be the best method to evaluate for PJI. Further research should be performed to establish new thresholds for these synovial inflammatory markers in the setting of THA dislocation and PJI.Level of evidenceLevel III; retrospective trial.     

Dual Mobility Cups in Revision Total Hip Arthroplasty: Efficient Strategy to Decrease Dislocation Risk

BackgroundRevision total hip arthroplasty (rTHA) is a challenging surgery with a higher rate of complications than primary arthroplasty, particularly instability and aseptic loosening. The purpose of this study is to compare dual mobility cup (DMC) and standard mobility cup (SMC) in all rTHAs performed at our institution over a decade with a 1 year minimum follow-up.MethodsTwo hundred ninety-five rTHAs (acetabular only and bipolar revisions) between 2006 and 2016 were retrospectively reviewed. These were divided into those with a DMC (184 revisions) or SMC (111 revisions). Dislocation and complications requiring re-revision were reported.ResultsThe rTHA mean age was 69 years ± 13.9 (19-92) and the mean follow-up was 2.3 years. Dislocation risk was statistically lower (P = .01) with a DMC (3.8%; 7/184) than with an SMC (13.5%; 15/111). DMC required re-rTHA in 24/184 (13%) for any reason compared to SMC in 19/111 (17.1%) (P = .34). There was no significant difference in early aseptic loosening (P = .28) between the 2 groups. For young patients (≤55 years), results were similar with a lower dislocation rate in the DMC group (P = .24) and no increased risk of early aseptic loosening (P = .49).ConclusionThis study demonstrates that for all rTHA indications DMC compared to SMC has a significantly decreased risk of postoperative dislocation without risk of early aseptic loosening at medium term follow-up. The use of DMC in rTHA is an important consideration particularly with the predicted increased incidence of both primary and revision THA globally.     

Risk of Dislocation and Revision Following Primary Total Hip Arthroplasty in Patients With Prior Lumbar Fusion With Spinopelvic Fixation

BackgroundThe effect of spinopelvic fixation in addition to lumbar spinal fusion (LSF) on dislocation/instability and revision in patients undergoing primary total hip arthroplasty (THA) has not been reported previously.MethodsThe PearlDiver Research Program was used to identify patients aged 30 and above undergoing primary THA who received (1) THA only, (2) THA with prior single-level LSF, (3) THA with prior 2-5 level LSF, or (4) THA with prior LSF with spinopelvic fixation. The incidence of THA revision and dislocation/instability was compared through logistic regression and Chi-squared analysis. All regressions were controlled for age, gender, and Elixhauser Comorbidity Index (ECI).ResultsBetween 2010 and 2018, 465,558 patients without history of LSF undergoing THA were examined and compared to 180 THA patients with prior spinopelvic fixation, 5,299 with prior single-level LSF, and 1,465 with prior 2-5 level LSF. At 2 years, 7.8% of THA patients with prior spinopelvic fixation, 4.7% of THA patients with prior 2-5 level LSF, 4.2% of THA patients with prior single-level LSF, and 2.2% of THA patients undergoing only THA had a dislocation event or instability (P < .0001). After controlling for length of fusion, pelvic fixation itself was associated with higher independent risk of revision (at 2 years: 2-5 level LSF + spinopelvic fixation: aHR = 3.15, 95% CI 1.77-5.61, P < .0001 vs 2-5 level LSF with no spinopelvic fixation: aOR = 1.39, 95% CI 1.10-1.76, P < .0001).ConclusionAt 2 years, spinopelvic fixation in THA patients were associated with a greater than 3.5-fold increase in hip dislocation risk compared to those without LSF, and an over 2-fold increase in THA revision risk compared to those with LSF without spinopelvic fixation.Level of EvidenceIII.     

Predictive Factors for Revision and Survivorship Analysis of a Prevalent 36-mm Metal-on-Metal Total Hip Replacement System: A Large Single-Center Retrospective Cohort Study

BackgroundTo our knowledge, this is the largest single-center cohort of the 36-mm Corail-Pinnacle metal-on-metal total hip replacements system, aiming to determine 10-year survivorship and identify predictors of revision. We further assessed year of implantation given reports of manufacturing variations affecting shells made after 2006 predisposing these components to increasing wear.MethodsAll Corail-Pinnacle 36-mm metal-on-metal hips implanted in a single center (2005-2012). The effect of patient and implant-related variables, and year of implantation on revision risk was assessed using Kaplan-Meier, Cox regression, and interrupted time series analysis.ResultsIn total, 1212 metal-on-metal total hip replacements were implanted with a 10-year survival rate of 83.4% (95% confidence interval [CI] = 81.3-85.5). Mean follow-up duration was 7.3 years with 61% of patients reaching a minimum of 7 years of follow-up. One hundred nineteen patients required revision surgery (9.8%). Univariate analysis identified female gender (hazard ratio [HR] = 1.608, CI = 1.093-2.364, P = .016), age at implantation (HR = 0.982, CI = 0.968-0.997, P = .019), smaller 50-mm to 54-mm cup diameter (HR = 1.527, CI = 1.026-2.274, P = .037), and high-offset stems (HR = 2.573, CI = 1.619-4.089, P < .001) as predictors of revision. Multivariate modeling confirmed female gender and high-offset stems as significant predictors of revision. For components implanted after 2007, the number of revisions showed no statistically significant step increase compared to pre-2007 implantation.ConclusionWe observed a high 10-year failure rate (16.6%) with this implant, mostly due to adverse reaction to metal debris. Female gender and high femoral offset stems were significant predictors for all-cause revision. Year of implantation was not significantly associated with an increasing number of revisions from 2007 onwards, although further studies to validate the impact of manufacturing discrepancies are recommended.     

Outcome and Risk Factors Associated with Failures of Isolated Bearing Exchange for Osteolysis in Well-Fixed Cementless Total Hip Arthroplasty

BackgroundIt is often challenging to decide whether to revise only the bearing or femoral acetabular component in the setting of progressive osteolysis without component loosening in revision total hip arthroplasty (THA). In this study, we aimed to (1) compare the survivorship of isolated bearing exchange and single/both component revision for patients with periprosthetic osteolysis without component loosening, and (2) identify potential risk factors associated with failures of isolated bearing exchange.MethodsA total of 228 consecutive cases of revision THA for progressive osteolysis without component loosening was evaluated in 2 groups: (1) 124 component revision and (2) 104 isolated bearing exchange. The primary outcome was survival, with failure defined as repeat revision or reoperation for any reason. Patient risk factors, such as demographics and medical comorbidities, were also analyzed.ResultsThere was no significant difference in survivorship between the component revision group and the bearing exchange group at 10 years (85% vs 82%; P = .89). There was no progression of osteolysis on radiographs at last follow-up for patients with isolated bearing change. Univariate regression modeling demonstrated that renal disease was associated with failure of isolated bearing exchange after revision THA.ConclusionThis study demonstrated that isolated bearing exchange is associated with similar outcomes compared with component revision for aseptic osteolysis without loosening, demonstrating that isolated bearing exchange is a viable option for selected patients with osteolysis in the setting of well-fixed THA components. This provides clinically useful information for surgeons in the surgical treatment of THA patients with wear and osteolysis without component loosening.     

Trabecular Metal Acetabular Components Reduce the Risk of Revision Following Primary Total Hip Arthroplasty: A Propensity Score Matched Study From the National Joint Registry for England and Wales

Background

Trabecular metal (TM)-coated acetabular components are increasingly used in both primary and revision total hip arthroplasty (THA). However, previous studies assessing TM acetabular components have been small single-center cohorts with most lacking a control group. We compared revision rates following primary THA between TM and non-TM-coated acetabular components.

Hip Arthroplasty Outcomes in the Presence of Kidney Failure: A National Data Linkage Study

BackgroundPatients who have kidney failure are at higher risk of requiring total hip arthroplasty (THA) and are at higher risk of complications. This study compared the rate of revision surgery and mortality following THA between patients who have kidney failure receiving long term dialysis or who had a kidney transplant and those who did not have kidney failure.MethodsA data linkage study was performed using data from 2 national registries: a registry of dialysis and kidney transplant patients and a registry of THA procedures. Both registries had coverage of almost all procedures or treatments in Australia. Data from September 1999 to December 2016 were used. Mortality and revision surgery were compared between patients receiving dialysis, those who had a functioning kidney transplant, and patients who did not have kidney failure using Cox and Fine-Gray (competing risk) regression models. A total of 383,478 primary THA procedures were identified as people receiving dialysis (n = 490), who had a functioning kidney transplant (n = 459), or who did not have kidney failure (n = 382,529).ResultsThere was no significant difference in the overall rate of revision surgery between the groups (dialysis versus no kidney failure HR = 1.20; 95% CI 0.76, 1.88, transplant versus no kidney failure (hazard ratio) HR = 1.01; 95% (confidence interval) CI 0.66, 1.53). The risk for death after surgery was significantly higher in the dialysis group compared to both the functioning transplant group (HR = 3.44; 95%CI 1.58, 7.5), and in those without kidney failure (HR = 4.13; 95%CI 3.25, 5.25).ConclusionThe rate of mortality after THA in patients on dialysis is higher than in patients who have a functioning transplant or those who do not have kidney failure, but there is no early excess mortality to suggest a difference in this metric due to the surgery.     

No Threshold Exists for Recommending Revision Surgery in Metal-on-Metal Hip Arthroplasty Patients With Adverse Reactions to Metal Debris: A Retrospective Cohort Study of 346 Revisions

BackgroundSurgeons currently have difficulty when managing metal-on-metal hip arthroplasty (MoMHA) patients with adverse reactions to metal debris (ARMD). This stems from a lack of evidence, which is emphasized by the variability in the recommendations proposed by different worldwide regulatory authorities for considering MoMHA revision surgery. We investigated predictors of poor outcomes following MoMHA revision surgery performed for ARMD to help inform the revision threshold and type of reconstruction.MethodsWe retrospectively studied 346 MoMHA revisions for ARMD performed at 2 European centers. Preoperative (metal ions/imaging) and intraoperative (findings, components removed/implanted) factors were used to predict poor outcomes. Poor outcomes were postoperative complications (including re-revision), 90-day mortality, and poor Oxford Hip Score.ResultsPoor outcomes occurred in 38.5%. Shorter time (under 4 years) to revision surgery was the only preoperative predictor of poor outcomes (odds ratio [OR] = 2.12, confidence interval [CI] = 1.00-4.46). Prerevision metal ions and imaging did not influence outcomes. Single-component revisions (vs all-component revisions) increased the risk of poor outcomes (OR = 2.99, CI = 1.50-5.97). Intraoperative modifiable factors reducing the risk of poor outcomes included the posterior approach (OR = 0.22, CI = 0.10-0.49), revision head sizes ≥36 mm (vs <36 mm: OR = 0.37, CI = 0.18-0.77), ceramic-on-polyethylene revision bearings (OR vs ceramic-on-ceramic = 0.30, CI = 0.14-0.66), and metal-on-polyethylene revision bearings (OR vs ceramic-on-ceramic = 0.37, CI = 0.17-0.83).ConclusionNo threshold exists for recommending revision in MoMHA patients with ARMD. However postrevision outcomes were surgeon modifiable. Optimal outcomes may be achieved if surgeons use the posterior approach, revise all MoMHA components, and use ≥36 mm ceramic-on-polyethylene or metal-on-polyethylene articulations.     

Excellent Long-Term Survival Rate of Polished,Tapered, Cemented Stems in Patients Aged 35 Years or Younger With Avascular Necrosis or Inflammatory Arthritis of the Hip

BackgroundTotal hip arthroplasty (THA) for avascular necrosis (AVN) or inflammatory arthritis (IA) comes with a relatively high risk of aseptic stem loosening, especially in young patients. There are limited long-term data on the survivorship of polished, tapered, cemented stems in this population. We therefore performed a single-center retrospective study investigating the survival of this particular stem type in young patients with AVN or IA.MethodsAll patients aged ≤35 years who had received a THA for AVN or IA operated on by the senior author between 1990 and 2010 at the University Hospitals Leuven were identified. In total, 85 THAs in 62 patients were included. Primary endpoint was revision of the femoral component for aseptic loosening. Secondary endpoints were revision of the acetabular component for aseptic loosening, revision for other reasons, and the presence of radiolucencies around the components.ResultsThe mean follow-up for the entire cohort was 18.0 ± 5.3 years (range 8.0-28.9). Taking revision for aseptic loosening as endpoint, the survival of cemented stems was 100% after 15 years and 95.1% after 20 years. Survival of uncemented cups (91.3%) was significantly better than survival of cemented cups (50.3%) after 20 years of follow-up for aseptic loosening. Taking revision for any reason as endpoint, the survival of THAs with uncemented and cemented cups was 90% and 43.1% at 20 years respectively. Radiolucencies developed in the cement mantles around 11 of the 81 nonrevised stems, mainly in zones 1 and 7.ConclusionIn this cohort of young patients with high-risk profiles for aseptic stem loosening, polished, tapered, cemented stems showed excellent long-term survival rates and they therefore remain a viable alternative to uncemented stem designs.