Patient-Reported Outcomes and Range of Motion Following Knee Arthroplasty Using a Megaprosthesis in Non-Oncological Patients: A Systematic Review

BackgroundThis review aimed to determine outcomes following megaprostheses in non-oncological indications for knee arthroplasty, including range of motion (ROM) and patient-reported outcome measures (PROMs) of function, pain, and quality of life (QoL).MethodsA search of MEDLINE, Embase, and Cochrane via Ovid, and PubMed between January 2003 and June 2023 was conducted. Studies reporting function, pain, ROM, and/or QoL in non-oncological patients who have received knee megaprostheses were included. Studies with sample sizes (n ≤ 5) were excluded. The risk of bias was assessed using the Downs and Black Quality Checklist for Health Care Intervention Studies. Central tendency measures (mean or median) were reported at each time point, and dispersion measures were extracted and reported whenever data were available.ResultsA total of 30 studies (involving 1,294 megaprostheses) were included. Of which, 14 of 30 studies reviewed patients who had mixed indications, 14 of 30 looked at fracture only; 1 of 30 focused on distal femur nonunion; and 1 of 30 focused on patients who had periprosthetic infections. The average patient follow-up time was 40.1 months (range, 1.0–93.5). Most studies presented a high risk of bias (27 of 30), while a few (3 of 30) presented a low risk of bias. Improvements from preoperative baseline were observed in 85.7% of studies that reported baseline and follow-up data for function (12 of 14), 100.0% pain (4 of 4), 90.9% ROM (10 of 11), and 66.6% QoL (2 of 3).ConclusionFavorable function, pain, ROM, and QoL outcomes following knee megaprostheses in non-oncological patients were observed. Heterogeneity in outcome measures and follow-up periods prevented the pooling of data. Future comparative studies are warranted to enhance the body of evidence relating to knee megaprostheses in non-oncological patients.