Outcomes Following Intraoperative Calcar Fractures During Cementless Total Hip Arthroplasty.

BACKGROUND: Intraoperative calcar fractures (IOCFs) are an established complication of cementless total hip arthroplasty (THA). Prompt recognition and management may prevent subsequent postoperative complications. This study aimed to evaluate the outcomes and revision rates of THAs with IOCFs identified and managed intraoperatively. METHODS: There were 11,438 primary cementless THAs performed at a single institution from 2009 to 2022. Prospectively collected data on cases with an IOCF was compared to cases without the complication. The fracture group had a lower body mass index (26.9 versus 28.9 kg/m2; P = .01). Patient age, sex, and mean follow-up (3.2 (0 to 12.8) versus 3.5 years (0 to 14); P = .45) were similar between groups. RESULTS: An IOCF occurred in 62 of 11,438 (0.54%) cases. The THAs done via a direct anterior approach experienced the lowest rate of fractures (31 of 7,505, 0.4%) compared to postero-lateral (27 of 3,759, 0.7%; P = .03) and lateral (4 of 165, 2.4%; P < .01) approaches. Of the IOCFs, 48 of 62 (77%) were managed with cerclage cabling, 4 of 62 (6.5%) with intraoperative stem design change and cabling, 4 of 62 (6.5%) with restricted weight-bearing, and 6 of 62 (9.7%) with no modification to the standard postoperative protocol. The IOCF group experienced one case of postoperative component subsidence. No subjects in the IOCF cohort required revision, and rates were similar between groups (0 of 62, 0% versus 215 of 11,376, 1.9%; P = .63). Postoperative Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement scores were comparable (85.7 versus 86.4; P = .80). CONCLUSIONS: Cementless THA complicated by IOCF had similar postoperative revision rates and patient-reported outcome measures at early follow-up when compared to patients not experiencing this complication. Surgeons may use these data to provide postoperative counseling on expectations and outcomes following these rare intraoperative events.

Debridement, Antibiotics, and Implant Retention in Unicompartmental Knee Arthroplasty Infection.

BACKGROUND: This multicenter study sought to further investigate the method and outcome of debridement, antibiotics, and implant retention (DAIR) for the management of unicompartmental knee periprosthetic joint infection (PJI). METHODS: This retrospective study was performed on 52 patients who underwent DAIR for PJI of a unicompartmental knee arthroplasty (UKA) across 4 academic medical centers, all performed by fellowship-trained arthroplasty surgeons. Patient demographics, American Society of Anesthesiologists score, infecting organism, operative data, antibiotic data, and success in infection control at 1 year were collected. RESULTS: The average time from index surgery to diagnosis of PJI was 11.1 weeks (range, 1.4 to 48). There was no correlation between time of diagnosis and success at 1 year (R = 0.09, P = .46). There was an association between surgical synovectomy and the eradication of infection (R = 0.28, P = .04). Overall, there was an 80.8% (42 of 52) infection-controlled success rate at 1 year from the DAIR procedure. All DAIR failures went on to require another procedure, either 1-stage (2 of 10) or 2-stage (8 of 10) revision to total knee arthroplasty (TKA). Of the DAIR successes, 6 (14.3%) went on to require conversion to TKA for progression of arthritis within 5 years. CONCLUSIONS: This study demonstrates that DAIR is a safe and moderately effective procedure in the setting of acute PJI of UKA across institutions, with a success rate consistent with DAIR for TKA. The data suggest that a wide exposure and thorough synovectomy be incorporated during the DAIR UKA to improve the likelihood of successful eradication of PJI at the 1-year mark. LEVEL OF EVIDENCE: Level III.

Outpatient Total Knee Arthroplasty From a Stand-Alone Surgery Center: Safe as the Hospital?

BACKGROUND: Literature suggests that outpatient arthroplasty may result in low rates of complications and readmissions. There is, however, a dearth of information on the relative safety of total knee arthroplasty (TKA) performed at stand-alone ambulatory surgery centers (ASCs) versus hospital outpatient (HOP) settings. We aimed to compare safety profiles and 90-day adverse events of these 2 cohorts. METHODS: Prospectively collected data were reviewed on all patients who underwent outpatient TKA from 2015 to 2022. The ASC and HOP groups were compared, and differences in demographics, complications, reoperations, revisions, readmissions, and emergency department (ED) visits within 90 days of surgery were analyzed. There were 4 surgeons who performed 4,307 TKAs during the study period, including 740 outpatient cases (ASC = 157; HOP = 583). The ASC patients were younger than HOP patients (ASC = 61 versus HOP = 65; P < .001). Body mass index and sex did not differ significantly between groups. RESULTS: Within 90 days, 44 (6%) complications occurred. No differences were observed between groups in rates of 90-day complications (ASC = 9 of 157, 5.7% versus HOP = 35 of 583, 6.0%; P = .899), reoperations (ASC = 2 of 157, 1.3% versus HOP = 3 of 583, 0.5%; P = .303), revisions (ASC = 0 of 157 versus HOP = 3 of 583, 0.5%; P = 1), readmissions (ASC = 3 of 157, 1.9% versus HOP = 8 of 583, 1.4%; P = .625), and ED visits (ASC = 1 of 157, 0.6% versus HOP = 3 of 583, 0.5%; P = .853). CONCLUSION: These results suggest that in appropriately selected patients, outpatient TKA can be safely performed in both ASC and HOP settings with similar low rates of 90-day complications, reoperations, revisions, readmissions, and ED visits.

Early Practice All-Cause Complications for Fellowship-Trained Anterior Hip Surgeons Are Not Increased When Compared to "Gold Standard" Experienced Posterior Approach Surgeons.

BACKGROUND: Increased complication rates have been reported during the learning curve for direct anterior approach (DAA) total hip arthroplasty (THA). However, emerging literature suggests that complications associated with the learning curve may be substantially reduced with fellowship training. METHODS: Our institutional database was queried to identify 2 groups: (1) 600 THAs comprised of the first 300 consecutive cases performed by 2 DAA fellowship-trained surgeons; and (2) 600 posterolateral approach (PA) THAs, including the most recent 300 primary cases performed by 2 experienced PA surgeons. All-cause complications, revision rates, reoperations, operative times, and transfusion rates were evaluated. RESULTS: Comparing DAA and PA cases, there were no significant differences in rates of all-cause complications (DAA = 18, 3.0% versus PA = 23, 3.8%; P = .43), periprosthetic fractures (DAA = 5, 0.8% versus PA = 10, 1.7%; P = .19), wound complications (DAA = 7, 1.2% versus PA = 2, 0.3%; P = .09), dislocations (DAA = 2, 0.3% versus PA = 8, 1.3%, P = .06), or revisions (DAA = 2, 0.3% versus PL = 5, 0.8%; P = .45) at 120 days postoperatively. There were 4 patients who required reoperation for wound complications, all within the DAA group (DAA = 4, 0.67% versus PA = 0; P = .045). Operative times were shorter in the DAA group (DAA <1.5 hours = 93% versus PA <1.5 hours = 86%; P < .01). No blood transfusions were given in either group. CONCLUSION: In this retrospective study, DAA THAs performed by fellowship-trained surgeons early in practice were not associated with higher complication rates compared to THAs performed by experienced PA surgeons. These results suggest that fellowship training may allow DAA surgeons to complete their learning curve period with complication rates similar to experienced PA surgeons.

Timing and Factors Associated With Revision for Infection After Primary Total Knee Arthroplasty Based on American Joint Replacement Registry Data.

BACKGROUND: Infection following total knee arthroplasty (TKA) remains a challenging clinical problem. Using American Joint Replacement Registry data, this study examined factors related to the incidence and timing of infection. METHODS: Primary TKAs performed from January 2012 through December 2018 among patients ≥65 years of age at surgery were queried from the American Joint Replacement Registry and merged with Medicare data to enhance capture of revisions for infection. Multivariate Cox regressions incorporating patient, surgical, and institutional factors were used to produce hazard ratios (HRs) associated with revision for infection and mortality after revision for infection. RESULTS: Among 525,887 TKAs, 2,821 (0.54%) were revised for infection. Men had an increased risk of revision for infection at all-time intervals (≤90 days, HR = 2.06, 95% CI: 1.75-2.43, P < .0001; >90 days to 1 year, HR = 1.90, 95% CI: 1.58-2.28, P < .0001; >1 year, HR = 1.57, 95% CI: 1.37-1.79, P < .0001). TKAs performed for osteoarthritis had an increased risk of revision for infection at ≤90 days (HR = 2.01, 95% CI: 1.45-2.78, P < .0001) but not at later times. Mortality was more likely among patients who had a Charlson Comorbidity Index (CCI) ≥ 5 compared to those who had a CCI ≤ 2 (HR = 3.21, 95% CI: 1.35-7.63, P = .008). Mortality was also more likely among older patients (HR = 1.61 for each decade, 95% CI: 1.04-2.49, P = .03). CONCLUSION: Based on primary TKAs performed in the United States, men were found to have a persistently higher risk of revision for infection, while a diagnosis of osteoarthritis was associated with a significantly higher risk only during the first 90 days after surgery.

Outcomes of fixed versus mobile-bearing medial unicompartmental knee arthroplasty.

Aims: The optimal bearing surface design for medial unicompartmental knee arthroplasty (UKA) remains controversial. The aim of this study was to compare outcomes of fixed-bearing (FB) and mobile-bearing (MB) UKAs from a single high-volume institution. Methods: Prospectively collected data were reviewed for all primary cemented medial UKAs performed by seven surgeons from January 2006 to December 2022. A total of 2,999 UKAs were identified, including 2,315 FB and 684 MB cases. The primary outcome measure was implant survival. Secondary outcomes included 90-day and cumulative complications, reoperations, component revisions, conversion arthroplasties, range of motion, and patient-reported outcome measures. Overall mean age at surgery was 65.7 years (32.9 to 94.3), 53.1% (1,593/2,999) of UKAs were implanted in female patients, and demographics between groups were similar (p > 0.05). The mean follow-up for all UKAs was 3.7 years (0.0 to 15.6). Results: Using revision for any reason as an endpoint, five-year survival for FB UKAs was 97.2% (95% CI 96.4 to 98.1) compared to 96.0% for MB (95% CI 94.1 to 97.9; p = 0.008). The FB group experienced fewer component revisions (14/2,315, 0.6% vs 12/684, 1.8%; p < 0.001) and conversion arthroplasties (38/2315, 1.6% vs 24/684, 3.5%; p < 0.001). A greater number of MB UKAs underwent revision due to osteoarthritis progression (FB = 21/2,315, 0.9% vs MB = 16/684, 2.3%; p = 0.003). In the MB group, 12 (1.8%) subjects experienced bearing dislocations which required revision surgery. There were 15 early periprosthetic tibia fractures (0.6%) in the FB group compared to 0 for MB (p = 0.035). Conclusion: In similar patient populations, FB UKAs demonstrated slightly higher survival than a commonly used MB design. Adverse event profiles differed by bearing type, with an increased risk of bearing dislocation and OA progression with MB designs, and early periprosthetic tibia fractures for FB designs.

Do the Principles of Motor Program Editing Apply to Longer Sequences of Rapid Aiming Movements? Part I.

Prior work had shown that performing a shorter distance aiming movement prior to a longer distance aiming movement resulted in overshooting of the short movement and undershooting of the longer movement compared to repetition of the same movement. The main question was whether the same interference effects would be found in a three-movement sequence. Right-handed (N = 24) participants (aged 18-22) produced a sequence of two or three bimanual rapid lever reversals combining short (20°) and long (60°) movements with an intermovement interval of 2.5 s beginning with either the dominant or nondominant hand. Participants overshot the short target and undershot the long target when short and long movements alternated compared to same distance control conditions, but the effects were greater for the nondominant hand. Overall, the experiment demonstrated that parameter value switching was a major source of spatial inaccuracy in sequential aiming movements.

Do the Principles of Motor Program Editing Apply to Longer Sequences of Rapid Aiming Movements? Part II.

In Part I of this study, it was shown that performing a shorter distance aiming movement prior to a longer distance aiming movement resulted in overshooting of the short movement and undershooting of the longer movement compared to control conditions. However, the finding was limited, unexpectedly, to the nondominant hand. To replicate the prior result and to determine the effect of practice organization on movement accuracy, right-handed (n =24) participants (aged 18-22) produced a sequence of three rapid lever reversals combining short (20°) and long (60°) movements with an intermovement interval of 2.5 s with the dominant hand. Greater overshooting of the short movements and greater undershooting of the long movement was shown with random practice compared to blocked practice for both same distance and different distance sequences, although spatial errors were greater in the different conditions compared to the same conditions. Overall, the experiment demonstrated parameter value switching and practice organization as two major sources of spatial inaccuracy in sequential aiming movements.