Abstract
Introduction
Manipulation under anesthesia (MUA) after total knee arthroplasty (TKA) helps restore range of motion. This study identifies MUA risk factors to support early interventions to improve functionality.
Methods
Data was retrospectively reviewed in 2,925 primary TKAs from October 2013 through December 2015 from 13 orthopedic surgeons using hospital and private practice electronic medical records (EMR).
Statistical analysis evaluated MUA and non-MUA groups, comparing demographic, operative, hospital-visit, and clinical factors. T-test, chi-square test, ANOVA and regression analysis were performed. Significance was set at p<0.05.
Results
Of 2,925 TKAs, 208 MUAs were performed (7.1%) with no significant differences between groups in sex, BMI, or diabetes status. Mean age of the MUA group was 61.98 years old, and 66.89 years old in the non-MUA group (p<0.005). The ratio of MUA patients with high cholesterol was 3.37% (7/208), and 1.10% (30/2717) in the non-MUA group (p=0.014). The ratio of African-American patients in the MUA group was 6.73% (14/208), and 2.94% (80/2717) in the non- MUA group (p=0.003). Of cases with device data recorded in the EMR (n=1890), MUA incidence in patients receiving a cruciate-retaining (CR) device was 14.58% (50/343), and 9.57% (148/1547) in patients receiving a posterior-stabilized (PS) device (p=0.006). A CR-device patient was 52.35% more likely to undergo MUA than a PS-device patient (95% CI, 1.13–2.05). MUA rate by surgeon training was 6.7% for joint fellowship, 6.8% for general fellowship, and 12.0% for sports medicine fellowship (p=0.015). Further analysis showed that rate of CR-device use was 13.3% for joint-fellowship trained surgeons, 10.2% for general fellowship, and 74.7% for sports medicine fellowship (p<0.001). With the numbers available for this investigation, there were no significant differences found between groups in relation to surgeon, high-volume (>150 TKAs annually) or low-volume surgeons, length of stay, discharge disposition, or smoking status.
Conclusion
MUA risk factors include a lower mean age, high cholesterol, African-American, surgeon fellowship training, and receiving a cruciate-retaining device.
