Abstract
As value-based care reshapes the landscape of orthopedic surgery, understanding how
insurance type influences patient-reported outcomes (PROMs) after total knee arthroplasty
(TKA) is increasingly important. While Traditional Medicare (TM) and Medicare Advantage
(MA) differ significantly in structure and access, limited data exist comparing functional
outcomes between these groups. This retrospective cohort study used a prospectively
collected institutional registry to evaluate 6,010 Medicare beneficiaries who underwent
primary TKA between 2016 and 2023. Patients were categorized by insurance type (TM
or MA) at the time of surgery. Primary PROMs included the KOOS pain, physical function
shortform (PS), and Joint Replacement (JR) subscales. Clinically meaningful improvement
was assessed using minimal clinically important difference (MCID), substantial clinical
benefit (SCB), and Patient Acceptable Symptom State (PASS) thresholds. Multivariable
logistic regression was performed to evaluate the independent association between
insurance type and each outcome, adjusting for demographic, clinical, and socioeconomic
covariates. At baseline, MA patients had significantly lower KOOS pain, PS, and JR
(p < 0.001). However, by 1-year follow-up, both groups achieved similar KOOS pain and
PS scores, and comparable PROM improvements from baseline. MA patients had slightly
lower KOOS JR scores (p = 0.006) at 1-year, but equivalent odds of achieving MCID, PASS, and SCB thresholds
across all KOOS domains after multivariable adjustment. Patient satisfaction at 1
year also did not differ by Medicare plan type (p = 0.729). Despite presenting with worse baseline functional status, MA patients achieved
similar postoperative outcomes, PROM gains, and satisfaction as their TM counterparts.
These findings suggest that MA enrollment does not negatively impact patient-perceived
benefit after TKA and may not warrant differential risk-adjustment in PROM-based value
assessments.
Keywords
arthroplasty - replacement - knee - Medicare Advantage
