Racial Differences in Manipulation Under Anesthesia Rates Following Total Knee Arthroplasty

Socioeconomic, Patient, and Hospital Determinants for the Utilization of Peripheral Nerve Blocks in Total Joint Arthroplasty

BACKGROUND

While peripheral nerve blocks (PNBs) are associated with various improved outcomes in patients undergoing total hip or knee arthroplasty (THA/TKA), disparities in PNB utilization have been reported. This study assessed the importance of socioeconomic, demographic, clinical, and hospital determinants in explaining PNB utilization using the population-attributable risk (PAR) framework. Subsequently, we examined the association between PNB use and 3 secondary outcomes: Centers for Medicare and Medicaid Services (CMS)-defined complications, 90-day all-cause readmissions, and length of stay >3 days.

METHODS

This retrospective cohort study included 52,926 THA and 94,795 TKA cases from the 5% 2012 to 2021 Medicare dataset. Mixed-effects logistic regression models measured the association between study variables and PNB utilization. Variables of interest were demographic (age, sex), clinical (outpatient setting, diagnosis, prior hospitalizations in the year before surgery, Deyo-Charlson index, obesity, (non)-opioid abuse, smoking), socioeconomic (neighborhood Social Deprivation Index, race and ethnicity) and hospital variables (beds, ownership, region, rurality, resident-to-bed ratio). The model was used for the calculation of variable-specific and variable category-specific PARs (presented in percentages), reflecting the proportion of variation in PNB use explained after eliminating variables (or groups of variables) of interest with all other factors held constant. Subsequently, regression models measured the association between PNB use and secondary outcomes. Associations are presented with odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

Socioeconomic and demographic variables accounted for only a small proportion of variation in PNB use (up to 3% and 7%, respectively). Clinical (THA: 46%; TKA: 34%) and hospital variables (THA: 31%; TKA: 22%) were the primary drivers of variation. In THA, variation by clinical variables was driven by increased PNB use in the inpatient setting (OR, 1.28 [95% CI, 1.07-1.53]) and decreased use in patients with ≥2 prior hospitalizations (OR, 0.72 [95% CI, 0.57-0.90]). Moreover, nonosteoarthritis diagnoses associated with reduced PNB utilization in THA (OR, 0.64 [95% CI, 0.58-0.72]) and TKA (OR, 0.35 [95% CI, 0.34-0.37]).In TKA, PNB use was subsequently associated with fewer complications (OR, 0.82 [95% CI, 0.75-0.90]) and less prolonged length of stay (OR, 0.90 [95% CI, 0.86-0.95]); no association was found for readmissions (OR, 0.98 [95% CI, 0.93-1.03]). In THA, associations did not reach statistical significance.

CONCLUSIONS

Among THA and TKA patients on Medicare, large variations exist in the utilization of PNBs by clinical and hospital variables, while demographic and socioeconomic variables played a limited role. Given the consistent benefits of PNBs, particularly in TKA patients, more standardized provision may be warranted to mitigate the observed variation.

Complications of Bicruciate-Retaining Total Knee Arthroplasty: The Importance of Alignment and Balance

Bicruciate-retaining total knee arthroplasty (BCR TKA) results in kinematics closer to the native knee and in greater patient satisfaction but information concerning its outcome and complications is lacking.The goal of this study is to report the clinical and radiological outcomes of BCR prosthesis implanted using a spacer-based gap balancing technique and to assess if some preoperative factors are associated with a worse prognosis.A cohort of 207 knees in 194 patients who underwent BCR TKA, with a minimum 1-year follow-up, was retrospectively analyzed.Patients were followed at 6 weeks, 6 months, 1 year, and then every following year postoperatively, and filled questionnaires (Knee Society and Knee injury and Osteoarthritis Outcome Score) at every visit. Clinical and radiological assessments included range of motion, knee alignment, pain, and complications as defined by the Knee Society's Standardized list and definition of Complication of Total Knee Arthroplasty.Forty-three knees (20.8%) suffered major complications. Twenty-one knees (10.1%) underwent revision at an average of 32.1 months after the index procedure. Revision-free survival at 100 months was 85.7%. Revision was performed for aseptic tibial loosening in eight knees (3.9%) and stiffness in five knees (2.4%). There were 29 reoperations other than revision (14.0%), the most frequent procedure being manipulation under anesthesia in 14 knees (6.8%). Minor complications included tendonitis (20.8%), persistent synovitis (6.8%), and superficial wound infections (6.3%).All outcomes scores were greatly improved at the 1-year follow-up compared with preoperatively (p < 0.001). However, maximum flexion at the last follow-up was significantly reduced compared with preoperatively (mean maximum flexion ± standard deviation: 119.9 ± 15.6 vs. 129.9 ± 14.4, p < 0.001). Aseptic tibial loosening was associated with a hypercorrection in varus of preoperative valgus knees (p = 0.012).BCR TKA can give functional results similar to other types of prostheses but involves a substantial risk of complications. Important factors that can explain failed BCR TKA and guide its use were identified, more particularly knee alignment and its role in aseptic tibial loosening.

Manipulation Following Primary Total Knee Arthroplasty is Associated With Increased Rates of Infection and Revision

BACKGROUND

Stiffness following total knee arthroplasty (TKA) is a disabling complication and manipulation under anesthesia (MUA) is often performed as an early intervention. Few studies have focused on the revision risk, infection risk, demographics, and clinical outcomes in Medicare patients undergoing MUA following primary TKA.

METHODS

We reviewed 142,440 patients who had primary TKA from a national database and identified 3,652 patients (2.6%) who underwent MUA. Patient demographics and comorbid conditions were evaluated to identify risk factors. Incidence of revision and periprosthetic joint infection (PJI) at 1-, 2-, and 5-year time points in a cohort of MUA patients was compared to patients who did not undergo MUA. Multivariate Cox regressions were used for statistical analyses.

RESULTS

The incidence of MUA was higher in Black versus White individuals (4.1 versus 2.5%, P < .001). Revision risk was significantly greater in the MUA group at 1-, 2-, and 5-year time points with a hazard ratio (HR) of, 3.81, 3.90, and 3.22 respectively, P < .001. One- and 2-year revision risk was significantly greater when MUA occurred at 6 to 12 months post-TKA when compared to <3 months, P < .05. Risk of PJI was significantly greater in the MUA group with a HR of 2.2, 2.2, and 2.1 at 1, 2, and 5 years, respectively P < .001.

CONCLUSION

The incidence of MUA was 2.6%. There was an increased incidence of revision surgery and PJI in patients undergoing MUA. Patients at increased risk for stiffness following TKA should be closely monitored and treated with early intervention to minimize risk of poor outcomes.