Contralateral Total Knee Arthroplasty More Than One Year Apart: Do Patient-Reported Outcomes and Healthcare Utilization Darticleiffer After Each Surgery?

Abstract

This study aimed to evaluate healthcare utilization and patient-reported outcomes between the first and second asynchronous contralateral total knee arthroplasty (TKA) surgeries performed more than one year apart. A cohort of 573 patients undergoing contralateral primary TKA (> one year between surgeries) from 2016 to 2021 was analyzed. The PROMs included Knee Disability and Osteoarthritis Outcome Score Pain (KOOS-Pain), Physical Function (KOOS-PS), Joint Replacement (KOOS-JR) scores, as well as Veterans Rand-12 (VR-12) mental component score (MCS). Achievement of Minimum Clinically Important Differences (MCID) and Patient Acceptable Symptom State (PASS) was assessed for each outcome score. Healthcare utilization outcomes included discharge disposition (DD), length of stay (LOS), and 90-day readmission rates. The mean time from 1^st surgery to 2^nd surgery was 609 days (interquartile range [IQR]: 439 to 893). Mean baseline KOOS-Pain (39 versus 44, P < 0.001), PS (52 versus 54, P < 0.001), and JR (42 versus 47, P < 0.001) were significantly lower before the 1^st surgery compared to the 2^nd surgery. The difference in all KOOS domains between baseline and 1-year postoperative score was significantly larger following the 1^st surgery. More patients achieved an MCID for KOOS-PS after the 1^st surgery (89 versus 83%, P = 0.012); however, there was no significant difference in MCID and PASS threshold achievement for the remaining KOOS domains. The achievement of 1-year satisfaction between the first and second surgery (94 versus 92%, P = 0.4) was not significantly different. The length of stay (LOS) was significantly shorter following the 2^nd surgery (1.7 versus 1.4 days, P < 0.001), whereas there was no difference in DD or 90-day readmission between the 1^st and 2^nd TKA surgeries. In contralateral TKA with over one year of difference between procedures, patients are likely to have a poorer baseline status before the first surgery as well as greater improvement after this procedure. However, meaningful clinical improvements can be expected after both surgeries, and healthcare utilization may be lower following the second surgery.