Higher Rates of Residual Postoperative Instability after Anterior Cruciate Ligament Reconstruction in Female Patients: A Systematic Review of Level II Studies

Abstract

Purpose: To compare revision rates and residual postoperative instability after anterior cruciate ligament (ACL) reconstruction based on biological sex. Methods: A systematic review was conducted according to the 2020 PRISMA guidelines. PubMed, Embase, MEDLINE, and Cochrane library databases were queried from database inception through October 2022. Level I and II prospectively-enrolling human clinical studies that compared revision rates and physical examination of postoperative stability after ACL reconstruction between male and female patients were included. Outcomes were stratified by patient sex and quantitatively compared using a χ2 test. Study quality was assessed using the MINORS criteria. Results: Four studies consisting of 406 patients (50% males) with a mean age of 25 years (range, 13.9-62 years) were identified. Mean follow-up time was 34.4 months (range, 22-60 months). Hamstring tendon autografts were used in 62% of ACL reconstructions in males and in 65% of ACL reconstructions in females, whereas bone-patellar tendon-bone autografts were used in 38% and 35% of procedures in males and females, respectively. A residual positive Lachman test result was more frequently reported among females compared to males (5.8% vs 0.6%; P = 0.03). No significant difference in revision rates or residual pivot-shift on examination was observed between males and females (P = 0.38 and P = 0.08, respectively). Conclusion: Female patients undergoing ACL reconstruction have higher reported rates of residual anterior instability with Lachman than male patients. However, no sex-based differences were identified with residual pivot-shift on examination or rate of revision ACL surgery. Level of Evidence: II; Systematic Review of level II studies.