A prospective study of the association between bone contusion and intra-articular injuries associated with acute anterior cruciate ligament tear.

BACKGROUND: Bone bruising, commonly found on magnetic resonance imaging (MRI) after anterior cruciate ligament (ACL) injury, may be associated with intra-articular injuries, but little is known about this association.

PURPOSE: To examine demographic factors and intra-articular injuries associated with bone bruising in patients undergoing ACL reconstruction.

STUDY DESIGN: Case-control study; Level of evidence, 3.

METHODS: Patients with ACL injury who had an MRI within 6 weeks and arthroscopy within 3 months of injury were included in this prospective study (N = 171). Presence and severity of bone bruising were determined from preoperative MRIs for each anatomic site: lateral femoral condyle (LFC), lateral tibial plateau (LTP), medial femoral condyle (MFC), and medial tibial plateau (MTP). Multiple logistic regression was used to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) for predictors of bruising and associations between bruising and intra-articular injuries found during arthroscopy. Outcomes included the presence of bruising and severity of lateral bruising (mild, moderate, severe vs none/minimal bruising).

RESULTS: Frequencies of bone bruising were as follows: 85% LTP, 77% LFC, 26% MTP, and 6% MFC. Patient age between 18 and 28 years (OR, 0.27; 95% CI, 0.09-0.82) and 29 years and older (OR, 0.18; 95% CI, 0.05-0.61) predicted less LFC bruising compared with patients aged 17 years and younger. Age (18-28 years: OR, 0.15; 95% CI, 0.03-0.66; ≥29 years: OR, 0.10; 95% CI, 0.02-0.68) and contact injuries (OR, 0.17; 95% CI, 0.04-0.78) predicted less moderate LFC bruising. Male sex predicted mild (OR, 6.16; 95% CI, 1.44-26.43), moderate (OR, 8.98; 95% CI, 1.96-41.19), and severe (OR, 15.66; 95% CI, 3.19-76.92) LFC bruising. Male sex also predicted mild LTP bruising (OR, 0.19; 95% CI, 0.05-0.83), and contact injuries predicted severe LTP bruising (OR, 5.01; 95% CI, 1.21-20.67). LFC bruising (OR, 2.57; 95% CI, 1.04-6.32) and LTP bruising (OR, 3.13; 95% CI, 1.06-9.23) were associated with lateral meniscal tears. Moderate (OR, 8.14; 95% CI, 1.93-34.27) and severe (OR, 15.30; 95% CI, 2.34-100.10) LTP bruising was associated with medial meniscal tears. MFC bruising and MTP bruising were not associated with any predictors or intra-articular injuries.

CONCLUSION: Bone bruising is more common and severe in young men, and lateral bone bruising is associated with lateral meniscal tears. Medial meniscal tears are associated with increased severity of LTP bruising.