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Published on: May 5, 2023
Comparative Analysis of Clinically Meaningful Recovery Trajectories Following Unicompartmental and Patello-femoral
Rohan Singh1, Donnell L Williams1, Jeremiah Alexander1
1Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Orthopaedic Surgery, Newton-Wellesley Hospital, Newton, Massachusetts.
Background:
Medial unicompartmental knee arthroplasty (UKA), lateral UKA, and patello-femoral arthroplasty (PFA) are established treatments for isolated compartmental knee osteoarthritis. Despite its growing popularity, the speed of functional recovery between procedures remains poorly defined. We assessed the time to the minimal clinically important difference (MCID) between procedures for various patient-reported outcome measures (PROMs).
Methods:
A retrospective review of 2,487 patients from a multi-institutional arthroplasty registry was conducted (1,938 medial UKA, 283 lateral UKA, and 256 PFA). The Knee Osteoarthritis Outcome Score-Physical Function Short-Form (KOOS-PS), Patient-Reported Outcomes Measurement Information System (PROMIS) Global Physical Health, and PROMIS Physical Function Short Form-10a (PF-10a) were used. Rates of MCID achievement and time-to-MCID were compared across cohorts using non-interval-censored and interval-censored survival analyses. Secondary outcomes included conversion to total knee arthroplasty, nonconversion reoperation, and predictors of PROM improvement.
Results:
Rates of MCID achievement did not differ significantly between procedures for any of the three PROMs. Median times to MCID for all three PROMs were similar across cohorts for both the non-interval-censored data and the interval-censored data (KOOS-PS: 1.0 versus 0.8 versus 1.3 months; P = 0.29; PROMIS Global Physical Health: 0.7 versus 0.8 versus 1.4 months; P = 0.69; PROMIS PF-10a: 1.4 versus 1.4 versus 1.8 months; P = 0.93). The two-year conversion rates were comparable, whereas PFA demonstrated higher two-year nonconversion reoperation rates (9.0 versus 1.7 versus 3.8%; P < 0.001). On multivariable analysis, PFA was associated with lower odds of improvement in PROMIS PF-10a scores compared with medial UKA (odds ratio 0.56; P = 0.022).
Conclusions:
Medial UKA, lateral UKA, and PFA demonstrated similar rates of MCID achievement and time-to-MCID. These findings support similar early recovery trajectories across partial knee arthroplasty procedures and provide valuable data for patient counseling and expectation management.