Perioperative Periprosthetic Femur Fractures are Strongly Correlated With Fixation Method: an Analysis From the American Joint Replacement Registry.

BACKGROUND: Perioperative periprosthetic femur fractures (PPFx) after total hip arthroplasty (THA) remain a leading cause of early stem failure and revision and are associated with high rates of morbidity and mortality. American Joint Replacement Registry (AJRR) data have been analyzed to determine the relationship of femoral stem fixation to PPFx revision. METHODS: All early (≤3 months from index arthroplasty) linked primary and revision hip arthroplasties reported to the AJRR between 2012 and 2017 were analyzed. We evaluated patient demographics, arthroplasty type (hemiarthroplasty vs THA), and stem fixation. RESULTS: A total of 10,277 linked revisions were reported to the AJRR during 2012-2017. Early PPFx requiring revision occurred in 628 patients (6.1%) due to osteoarthritis (82.4%), femoral neck fracture (12.1%), and other causes (15.6%). Five hundred twenty-nine patients (84%) were treated with THA and 99 patients with hemiarthroplasty (16%). Females (70%) have a higher prevalence of revisions. Fifty-eight percent of patients were ≥70 years of age, and 20% were ≥80 years of age. Patients with cementless stems were 2.6 times (account 94.9% of the fractures, 95% confidence interval 0.59-11.1) more likely to undergo early revision for PPFx than those with cemented fixation, although not statistically significant with its sample size. CONCLUSION: Mirroring other studies and national registries, there was an association between cementless fixation and PPFx in AJRR. Nevertheless, AJRR data demonstrate a trend of increasing utilization of cementless femoral fixation for THA and hemiarthroplasty, with cementless fixation accounting for 93% of THA stems with early periprosthetic fracture. Additional analysis is needed to better understand this phenomenon, especially in the elderly.

Erratum to: Editorial: Do Orthopaedic Surgeons Belong on the Sidelines at American Football Games?

In the November Editorial, "Editorial: Do Orthopaedic Surgeons Belong on the Sidelines at American Football Games?" a statistic was attributed to a JAMA study (Ref. 10) that should have been attributed to an article from the New York Times (Ref. 16). The sentence in question should read: "We accept that critique, provided that the skeptics acknowledge that the best-case estimate in support of the safety of football would result in a CTE prevalence estimate of 9%, since only another 1200 ex-NFL players have died [16] since this research group [10] began studying football players' brains."

Does operative time affect infection rate in primary total knee arthroplasty?

BACKGROUND: Prolonged operative time may increase the risk of infection after total knee arthroplasty (TKA). Both surgeon-related and patient-related factors can contribute to increased operative times. QUESTIONS/PURPOSES: The purpose of this study was to determine (1) whether increased operative time is an independent risk factor for revision resulting from infection after TKA; (2) whether increasing body mass index (BMI) increased operative time; and (3) whether increasing experience substantially decreased operative time. METHODS: We retrospectively evaluated primary TKAs from our joint registry between March 2000 and August 2012. Cox proportional hazard models were used to assess the relationship between operative time and revision resulting from infection after accounting for age, sex, BMI, and Agency for Healthcare Research and Quality comorbidity score. Of 9973 instances of primary TKA, 73 underwent revision surgery for infection (0.73%). RESULTS: After accounting for the confounders of age and sex, operative time was not found to have a significant effect; a 15-minute increase in operative time increased the hazard of revision resulting from infection by only 15.6% (p=0.053; 95% confidence interval, 0.0%-34.0%). In addition, a five-unit increase in BMI was found to increase mean operative time by 1.9 minutes, on average, regardless of sex (p<0.0001). Operative time decreases with increasing experience but appears to plateau at approximately 300 surgeries. CONCLUSIONS: Operative time is only one of many factors that may increase infection risk and may be influenced by numerous confounders. Increasing BMI increased operative time but the effect was modest. The effect of increasing experience on operative duration of this common procedure was surprisingly limited among our surgeons. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Efficacy of revision surgery for the dislocating total hip arthroplasty: report from a large community registry.

BACKGROUND: Historically, achieving stability for the unstable total hip arthroplasty (THA) with revision surgery has been achieved inconsistently. Most of what we know about this topic comes from reports of high-volume surgeons' results; the degree to which these results are achieved in the community is largely unknown, but insofar as most joint replacements are done by community surgeons, the issue is important. QUESTIONS/PURPOSES: We used a community joint registry to determine: (1) the frequency of repeat revision after surgery to treat the unstable THA; (2) what surgical approaches to this problem are in common use in the community now; (3) are there differences in repeat revision frequency that vary by approach used; and (4) has the frequency of repeat revision decreased over time as surgical technique and implant options have evolved? METHODS: We reviewed 6801 primary THAs performed in our community joint registry over the last 20 years. One hundred eighteen patients (1.7%) with a mean age of 67 years were revised within the registry for instability/dislocation. Failure was defined as a return to the operating room for rerevision surgery for instability. Minimum followup was 2 years (average, 9.4 years; range, 2-20 years) with six patients having incomplete followup. The frequency of rerevisions was calculated and compared using Pearson's chi-square test. Cumulative rerevision rates were calculated using the Kaplan-Meier method and types of revision procedures were compared using the log-rank test. RESULTS: The initial revision procedure was successful in 108 patients (92%); 10 patients underwent repeat surgery for recurrent dislocation after their initial revision surgery. The most frequently performed procedure was revision of the head and liner only (35 of 118 [30%]); constrained devices were used in 19% (22 of 118) of the procedures. There was no difference in the cumulative rerevision rates for instability or dislocation by type of revision procedure performed. Six of 22 constrained liners were rerevised for varying indications. There was no difference in frequency of repeat revision for instability between those patients revised for THAs performed before 2003 and those managed more recently. CONCLUSIONS: Revision surgery for unstable THA is successfully managed in the community with a variety of surgical interventions. Identifying the reason for dislocation and addressing the source remain paramount. Constrained liners should be used with caution; although typically used in the most problematic settings, rerevision for a variety of failure modes remains troublesome. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Risk factors for periprosthetic joint infection following primary total hip arthroplasty: a case control study.

The purpose of this study was to identify the specific comorbidities and demographic factors that are independently associated with an increased risk of periprosthetic joint infection (PJI) in total hip arthroplasty (THA) patients. A case-control study design was used to compare 88 patients who underwent unilateral primary THA and developed PJI with 499 unilateral primary THA patients who did not develop PJI. The impact of 18 comorbid conditions and other demographic factors on PJI was examined. Depression, obesity, cardiac arrhythmia, and male gender were found to be independently associated with an increased risk of PJI in THA patients. This information is important to consider when counseling patients on the risks associated with elective THA, and for risk-adjusting publicly reported THA outcomes.

Improved survival of uncemented versus cemented femoral stems in patients aged < 70 years in a community total joint registry.

BACKGROUND: Aseptic loosening of the femoral stem remains a significant reason for revision in total hip arthroplasty (THA). Although stem fixation methods have changed over time, there is relatively little evidence supporting cemented or uncemented stems as more durable constructs. QUESTIONS/PURPOSES: We examined whether there was a difference in survival to revision between cemented and uncemented THA stems (1) for any reason; (2) for aseptic loosening or loosening related to wear/osteolysis; (3) based on patient age groupings (as a proxy for patient activity level); and (4) based on procedural timeframe groupings between cemented and uncemented stems. METHODS: A total of 6498 primary cemented and uncemented THAs were registered in our community total joint replacement registry between 1991 and 2011. Analysis was performed to compare age, sex, procedural timeframe, and diagnosis for both groups. Our primary outcome was revision of the stem component for aseptic loosening or loosening secondary to wear/osteolysis. Analyses were done using Wilcoxon rank sum tests, Pearson's chi-square tests, Kaplan Meier methods, and Cox regression. RESULTS: After adjusting for age, sex, primary diagnosis, and procedural timeframe as confounders, cemented femoral stem components were 1.63 times as likely as uncemented stems to be revised for any reason (p = 0.02) and 3.76 times as likely as uncemented stems to be revised for aseptic loosening or loosening related to wear/osteolysis (p < 0.001). When grouped by age, specifically in regard to revisions for aseptic loosening or loosening related to wear/osteolysis, uncemented stems had lower cumulative revision rates in patients aged < 70 years (p < 0.001) compared with cemented stems. There was a trend away from cemented fixation in our registry, which shifted from over 80% cemented stem use in 1996 to 3% in 2011. CONCLUSIONS: We found that uncemented stems were associated with fewer revisions for aseptic loosening in patients < 70 years old, but when all reasons for revision were considered, neither group demonstrated superior survival. With a mean followup of 6.5 years, longer followup is needed to verify these results over time.

Cumulative revision rate is higher in metal-on-metal THA than metal-on-polyethylene THA: analysis of survival in a community registry.

BACKGROUND: Metal-on-metal (MOM) THA bearing technology has focused on improving the arc of motion and stability and minimizing wear compared with traditional metal-on-polyethylene (MOP) bearing couples. It is unclear whether this more costly technology adds value in terms of improved implant survival. QUESTIONS/PURPOSES: This study evaluated Kaplan-Meier survival, revisions for dislocation, and cost of MOM THA compared with metal-on-cross-linked polyethylene (MOXP) THA in a community joint registry, with subset analysis of the recalled Depuy ASR™ implant. METHODS: All MOM THAs (resurfacings excluded) performed between January 2002 and December 2009 were included (n = 1118) and compared with a control group of MOXP THAs (n = 1286) done during the same time. Analysis was performed to compare age, gender, cost of implant, length of stay, year of index procedure, diagnosis, head size (< 32 mm versus ≥ 32 mm), revision and revision reason for both groups. Analysis at a mean of 3.6 years was done using Wilcoxon rank sum tests, Pearson's chi-square tests, Kaplan Meier methods, and Cox regression. RESULTS: The cumulative revision rate (CRR) was higher in MOM implants than in MOXP implants (MOM CRR = 13%; MOXP CRR = 3%). MOM implants were three times as likely to be revised as MOXP implants after adjustment for age, head size, and year of procedure. The recalled DePuy ASR™ implant was six times as likely to be revised as other MOM THAs. After removing the ASR™ implants from analysis, survivorship of MOM implants was not better than that of the MOXP hips. CONCLUSIONS: During the study time, MOM THAs showed inferior survival to MOXP THAs after adjusting for age, head size, and year of procedure. Longer followup is necessary to see whether MOM THAs add value in younger patient groups.

Failure of irrigation and débridement for early postoperative periprosthetic infection.

BACKGROUND: Irrigation and débridement (I&D) of periprosthetic infection (PPI) is associated with infection control ranging from 16% to 47%. Mitigating factors include organism type, host factors, and timing of intervention. While the influence of organism type and host factors has been clarified, the timing of intervention remains unclear. QUESTIONS/PURPOSES: We addressed the following questions: What is the failure rate of I&Ds performed within 90 days of primary surgery? And what factors are associated with failure? METHODS: We performed a multicenter retrospective analysis of I&D for PPI within 90 days of primary surgery. We included 86 patients (44 males, 42 females) with an average age of 61 years. Failure was defined as return to the operating room for an infection-related problem. We determined the failure rate of I&D within 90 days of primary surgery and whether the odds of rerevision for infection were associated with Charlson Comorbidity Index, age, sex, joint, organism type, and timing. The minimum followup was 24 months (average, 46 months; range, 24-106 months). RESULTS: 54 of 86 patients (63%) failed. Eight of 10 (80%) failed within the first 10 days, 32 of 57 (56%) within 4 weeks, and 22 of 29 (76%) within 31 to 90 days postoperatively. No covariates were associated with subsequent revision surgery for infection. CONCLUSIONS: I&D for PPI is frequently used in the early postoperative period to control infection. While it is assumed early intervention will lead to control of infection in most cases, our data contradict this assumption.

Revision surgery for patellofemoral problems: should we always resurface?

BACKGROUND: Routine patellar resurfacing performed at the time of knee arthroplasty is controversial, with some evidence of utility in both TKA (tricompartmental) and bicompartmental knee arthroplasty. However, whether one approach results in better implant survival remains unclear. QUESTIONS/PURPOSES: We asked whether (1) routine patellar resurfacing in TKAs resulted in lower cumulative revision rates compared to bicompartmental knee arthroplasties, (2) patella-friendly implants resulted in lower cumulative revision rates than earlier designs, and (3) bicompartmental knee arthroplasties revised to TKAs had higher cumulative revision rates than primary TKAs. PATIENTS AND METHODS: From a community-based joint registry, we identified 8135 patients treated with 9530 cemented, all-polyethylene patella TKAs and 627 bicompartmental knee arthroplasties without patellar resurfacing. We compared age, gender, year of index procedure, diagnosis, cruciate status, revision, and revision reason. RESULTS: TKAs had a lower cumulative revision rate for patella-only revision than bicompartmental knee arthroplasties (0.8% versus 4.8%). Adjusting for age, bicompartmental knee arthroplasties were 6.9 times more likely to undergo patellar revision than TKAs. There was no difference in the cumulative revision rate for patella-only revisions between patella-friendly and earlier designs. The cumulative revision rate for any second revision after a patella-only revision was 12.7% for bicompartmental knee arthroplasties while that for primary TKAs was 6.3%. CONCLUSIONS: Bicompartmental knee arthroplasties had higher revision rates than TKAs. Femoral component design did not influence the cumulative revision rate. Secondary patella resurfacing in a bicompartmental knee arthroplasty carried an increased revision risk compared to resurfacing at the time of index TKA. To reduce the probability of reoperation for patellofemoral problems, our data suggest the patella should be resurfaced at the time of index surgery.

Is there a preferred articulating spacer technique for infected knee arthroplasty? A preliminary study.

BACKGROUND: Periprosthetic infection in TKA is a devastating and challenging problem for both patients and surgeons. Two-stage exchange arthroplasty with an interval antibiotic spacer reportedly has the highest infection control rate. Studies comparing static spacers with articulating spacers have reported varying ROM after reimplant, which could be due to differences in articulating spacer technique. QUESTIONS/PURPOSES: We therefore determined whether one of three articulating spacer techniques was superior in terms of (1) infection control, (2) final ROM, and (3) cost. PATIENTS AND METHODS: We retrospectively reviewed 53 patients with infected TKAs who had two-stage exchange arthroplasty with one of three techniques with articulating spacers: autoclaving an original component (n = 15), a new femoral component (n = 16), and a silicone mold component (n = 22). We compared infection control, ROM, and cost. Minimum followup was 12 months (mean, 39 months; range, 12-105 months). RESULTS: We found no difference in infection control among the three techniques. Infection control was achieved in 13 of 15 (86.7%) autoclaved original component spacers at mean 73 months (range, 37-105 months), 15 of 16 (93.8%) new femoral component spacers at mean 19 months (range, 12-32 months), and 20 of 22 (90.9%) silicone mold component spacers at mean 32 months (range, 14-56 months). Mean final flexion was 95.7°, 98.3°, and 93.8°, respectively. Direct costs for all implants, molds, cement, and antibiotics were $932, $3589, and $3945, respectively. CONCLUSIONS: We found comparable infection control and ROM for the three techniques. Direct cost was least for the autoclaved original component technique.

Can this prosthesis be saved?: implant salvage attempts in infected primary TKA.

BACKGROUND: Open débridement with polyethylene liner exchange (ODPE) remains a relatively low morbidity option in acute infection of total knee arthroplasty (TKA), but concerns regarding control of infection exist. We sought to identify factors that would predict control of infection after ODPE. METHODS: We identified 44 patients (44 knees) with culture-positive periprosthetic infection who underwent ODPE. Failure was defined as any reoperation performed for control of infection or the need for lifetime antibiotic suppression. Patients had been followed prospectively for a minimum of 1 year (mean, 5 years; range, 1-9 years). RESULTS: Twenty-five of the 44 patients (57%) failed ODPE. Of these 25 patients, two had one additional procedure, 21 had more than one additional procedure, and two required lifetime antibiotic suppression. Failure rates tended to differ based on primary organism: 71% of Staphylococcus aureus periprosthetic infection failed versus 29% of Staphylococcus epidermidis, although with the limited numbers theses differences were not significant. Age, gender, or measures of comorbidity did not influence the risk of failure. There was no difference in failure rate (58% versus 50%) when the ODPE was performed greater than 4 weeks after index TKA. After a failed ODPE, 19 of the 25 failures went on to an attempted two-stage revision procedure. In only 11 of these 19 cases was the two-stage revision ultimately successful. CONCLUSIONS: Eradication of infection with ODPE in acute TKA infections is unpredictable; certain factors trend toward increased success but no firm algorithm can be offered. The success of two-stage revision for infection may be diminished after a failed ODPE. LEVEL OF EVIDENCE: Level III, retrospective comparative study. See Guidelines for Authors for a complete description of levels of evidence.

Do "premium" joint implants add value?: analysis of high cost joint implants in a community registry.

BACKGROUND: Numerous joint implant options of varying cost are available to the surgeon, but it is unclear whether more costly implants add value in terms of function or longevity. QUESTIONS/PURPOSES: We evaluated registry survival of higher-cost "premium" knee and hip components compared to lower-priced standard components. METHODS: Premium TKA components were defined as mobile-bearing designs, high-flexion designs, oxidized-zirconium designs, those including moderately crosslinked polyethylene inserts, or some combination. Premium THAs included ceramic-on-ceramic, metal-on-metal, and ceramic-on-highly crosslinked polyethylene designs. We compared 3462 standard TKAs to 2806 premium TKAs and 868 standard THAs to 1311 premium THAs using standard statistical methods. RESULTS: The cost of the premium implants was on average approximately $1000 higher than the standard implants. There was no difference in the cumulative revision rate at 7-8 years between premium and standard TKAs or THAs. CONCLUSIONS: In this time frame, premium implants did not demonstrate better survival than standard implants. Revision indications for TKA did not differ, and infection and instability remained contributors. Longer followup is necessary to demonstrate whether premium implants add value in younger patient groups. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.