The Effects of Different Management Strategies or Rehabilitation Approaches on Knee Joint Structural and Molecular Biomarkers Following Traumatic Knee Injury: A Systematic Review of Randomized Controlled Trials for the OPTIKNEE Consensus

OBJECTIVE: To summarize the effectiveness of management strategies and rehabilitation approaches for knee joint structural and molecular biomarker outcomes following anterior cruciate ligament (ACL) and/or meniscal tear.

DESIGN: Intervention systematic review.

LITERATURE SEARCH: We searched the MEDLINE, Embase, CINAHL, CENTRAL, and SPORTDiscus databases from their inception up to November 3, 2021.

STUDY SELECTION CRITERIA: We included randomized controlled trials (RCTs) investigating the effectiveness of management strategies or rehabilitation approaches for structural/molecular biomarkers of knee joint health following ACL and/or meniscal tear.

DATA SYNTHESIS: We included 5 RCTs (9 papers) with primary ACL tear (n = 365). Two RCTs compared initial management strategies (rehabilitation plus early vs optional delayed ACL surgery), reporting on structural biomarkers (radiographic osteoarthritis, cartilage thickness, meniscal damage) in 5 papers and molecular biomarkers (inflammation, cartilage turnover) in 1 paper. Three RCTs compared different post-ACL reconstruction (ACLR) rehabilitation approaches (high vs low intensity plyometric exercises, accelerated vs nonaccelerated rehabilitation, continuous passive vs active motion), reporting on structural biomarkers (joint space narrowing) in 1 paper and molecular biomarkers (inflammation, cartilage turnover) in 2 papers.

RESULTS: There were no differences in structural or molecular biomarkers between post-ACLR rehabilitation approaches. One RCT comparing initial management strategies demonstrated that rehabilitation plus early ACLR was associated with greater patellofemoral cartilage thinning, elevated inflammatory cytokine response, and reduced incidence of medial meniscal damage over 5 years compared to rehabilitation with no/delayed ACLR.

CONCLUSION: Very low-certainty evidence suggests that different initial management strategies (rehabilitation plus early vs optional delayed ACL surgery) but not postoperative rehabilitation approaches may influence the incidence of meniscal damage, patellofemoral cartilage loss and cytokine concentrations over 5 years post-ACL tear.