Retrospective analysis of return to impact sport after medial unicompartmental knee arthroplasty based on a cohort of 92 patients

Background: Return to sport after Knee Arthroplasty has been investigated reporting modifications in the physical activities with a trend towards to lower impact sports after Unicompartemental Knee Arthro-plasty. The purpose of this study was to analyze the return to sport level after medial unicompartmental knee arthroplasty (MUKA) in a population of osteoarthritic patients having practiced impact sport, defined with a University of California at Los Angeles activity scale (UCLA) >= 9 in their pre-symptomatic arthritic period.Hypothesis: Return to an impact sport after MUKA was possible for a population of osteoarthritic patients having practiced impact sport in their pre-symptomatic arthritic period.Methods: Ninety-two MUKA with a pre-symptomatic arthritic UCLA score >= 9, including 60 men (65.2%) and operated between January 2009 and September 2014, were evaluated by a dedicated survey. Infor-mations were obtained concerning the physical activities (intensity, frequency, kind of sport, reasons to decrease or stop the physical activities in the pre-and the postoperative period). The average age was 64.9 years +/- 6.4 (range 49-74.4). Three different periods were compared: pre-symptomatic arthritic, preoperative and postoperative period. The mean follow-up was 7.3 +/- 1.7 years. Results: The mean pre-symptomatic arthritic UCLA score was 9.9 +/- 0.3, the mean preoperative UCLA score was 7.0 +/- 2.5 (2-10) and the mean postoperative UCLA score was 7.2 +/- 2.0 (3-10). There were significant differences for the mean UCLA score values between pre-symptomatic arthritis and postoperative UCLA scores (p = 0.034), however no difference was detected in mean score values before and after surgery (p = 0.09). Only 32.6% (30/92) of patients had a postoperative UCLA score >= 9. For patients practicing an impact sport activity (UCLA >= 9) in the preoperative period (23/92; 25%), the postoperative UCLA score was at 8 +/- 1.1 (range 4-10). In this subgroup, 47.8% (11/23) of patients had a postoperative UCLA score >= 9. The decline in sports in postoperative was predominantly explained by residual pain of the operated knee (31/92; 34%), precaution to not damage the prosthesis (25/92; 27%) and restrictions due to another joint (19/92; 21%).Discussion: Return to impact sport after MUKA seems to be limited to a restrained number of patients. The main reasons to the decline in sporting activity level are linked to the residual pain of the operated knee and the precaution to not damage the prosthesis. Level of evidence: IV, retrospective cohort study.(c) 2023 Elsevier Masson SAS. All rights reserved.