Posterior tibial bone bruising associated with posterior-medial meniscal tear in patients with acute anterior cruciate ligament injury.

purposeTo evaluate whether medial-sided bone bruising was associated with postero-medial meniscal tears in patients with an acute rupture of their anterior cruciate ligament (ACL).

methodsA retrospective analysis of 150 consecutive patients who had an MRI scan within 8 weeks of their ACL rupture that underwent an ACL reconstruction was performed. Based on the intra-operative findings, two groups were identified: Group A (N = 75) had no postero-medial meniscal tear associated with the acute ACL rupture and Group B (N = 75) had a postero-medial meniscal tear found at time of reconstruction. All patients' pre-operative MRI scans were reviewed for bone bruising in the following anatomic sites: lateral femoral condyle (LFC), lateral tibial plateau (LTP), medial femoral condyle (MFC), and medial tibial plateau (MTP).

resultsMTP bone bruising was found to be more prevalent in cases that had a postero-medial meniscal tear in the setting of an acute ACL injury (p = 0.046). MTP Grade 2 or 3 bone bruising was more common in patients that had a postero-medial meniscal tear (p = 0.046). There was a slightly higher incidence of grade 2 or 3 MTP bone bruising in cases with a postero-medial meniscal tear, although this did not reach statistical significance (n.s.) There was no difference in LFC, LTP or MFC bone bruising in patients with or without a postero-medial meniscal tear (n.s) for all.

conclusionsMedial-sided bone bruising; especially present on the posterior tibial plateau may result from a higher injury force during the injury to the ACL. The identification of medial bone bruising on pre-operative MRI imaging following an acute ACL rupture should raise the suspicion of an associated postero-medial meniscal tear. LEVEL OF EVIDENCE: III.