Limited evidence that the presence of a bone bruise alone affects the clinical outcome of surgically reconstructed anterior cruciate ligaments: a systematic review.

IMPORTANCE Anterior cruciate ligament (ACL) injury can be a devastating injury that without surgery may lead to chronic instability. Although surgical reconstruction recreates the stabilising constraint of the native ACL, postoperative pain and subsequent arthrosis may follow. OBJECTIVES The primary objective of this systematic review is to determine whether the presence of a bone bruise following ACL rupture adversely affects the clinical outcomes following surgical reconstruction. EVIDENCE REVIEW A standardised research protocol was used as outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Studies included for review were those of high level of evidence (I or II) and had MRI data on the presence of bone bruise and clinical outcome measures in patients who underwent surgical reconstruction of the ACL after traumatic rupture. Articles were searched using PubMed/ Medline, Cochrane Library, CINAHL and EMBASE databases using a keyword search. Article references and conference proceedings were subsequently reviewed on identification of articles found via the keyword search. Non-English literature, animal and basic science studies, studies focused on the skeletally immature and low level of evidence (III, IV, V) were excluded. A quantitative analysis of the data retrieved was summarised. FINDINGS Five studies met the inclusion criteria. Follow-up ranged from the time of surgical reconstruction to 165 months. Although a variety of clinical outcome measures were used across studies, bone bruise cohorts did not demonstrate clinically inferior outcome scores. CONCLUSIONS AND RELEVANCE Although osteochondral injury is frequently identified following ACL injury, the presence of a bone bruise alone does not appear to significantly adversely affect the clinical outcome of surgically reconstructed ACLs. However, factors such as articular cartilage injury and alteration in joint loading may be important variables for further research. LEVEL OF EVIDENCE IV.