• PURPOSE
    • The aim of this meta-analysis was to compare the risk of stiffness between early and delayed anterior cruciate ligament (ACL) surgery in studies that use a modern accelerated rehabilitation protocol.
  • METHODS
    • Medline, Embase, and the Cochrane library were searched for studies that compared outcomes for early and delayed ACL reconstruction with a modern accelerated rehabilitation protocol. Risk ratios for stiffness were pooled using random effects meta-analysis.
  • RESULTS
    • A total of 8 studies were included in this review. The 3 randomized trials found no difference in the risk of postoperative stiffness at cutoff points of <2, <3, and <10 weeks between early surgery and delayed surgery. An analysis of the 7 studies whose outcomes could be pooled revealed no significant increase in risk of adverse outcomes with early surgery using a variety of cutoff points (1, 2, 10, 12, and 20 weeks). Sensitivity analysis of individual outcomes failed to show any significant difference between early and delayed surgery with respect to arthrofibrosis, stiffness, range of motion deficits, extension deficits, and flexion deficits.
  • CONCLUSIONS
    • If a modern surgical technique and an accelerated rehabilitation protocol are used, there is no increased risk of knee stiffness if an ACL reconstruction is performed as early as 1 week after injury.
  • LEVEL OF EVIDENCE
    • Level II, meta-analysis of Level I and II studies.