A better understanding of how patient-reported outcome measures (PROMs) change after total knee and hip arthroplasties (TKA and THA) is needed to support the minimum arbitrary follow-up of 24-months required by orthopedic journals. Therefore, our purpose was to perform a systematic review and meta-analysis of the THA and TKA literature to determine if equivalence exists between 12- and 24-month outcomes data.
A search was performed using the PubMed and EMBASE databases for primary and revision THA and TKA studies reporting PROMs data at both 12 and 24 months. Reports on PROMs for TKA and THAs were included for meta-analysis to detect statistical differences at 12 and 24 months.
A total of 15 reports from 9 TKA (n = 1564) and 6 THA (n = 740) reports were analyzed. The mean change between 12 and 24 months for Knee Society Score was 0.15 absolute points (95% confidence interval [CI]: 0.97-1.06, P = .13) and for Western Ontario and McMaster Universities Osteoarthritis index was 0.50 absolute points (95% CI: 0.94-1.07, P = .49). The mean change between 12 and 24 months for Harris Hip Score was 2.01 absolute points (95% CI: 0.94-1.1, P = .22) and for short form was 0.02 absolute points (95% CI: 0.92-1.08, P = .94).
No different outcomes were found within THA and TKA for 4 PROMs at 12- and 24-month follow-up. Although the findings from this study do not alleviate the need for collecting data from longer follow-up periods, there may not be additional value in collecting short-term outcomes data in routine practice at both 1 and 2 years.