Severe bone contusion is a risk factor for poor healing of the anterolateral ligament tear following anterior cruciate ligament reconstructions.

Abstract

A previous study demonstrated that incidence of residual pivot shift following anterior cruciate ligament (ACL) reconstructions was significantly higher in the poorly healed anterolateral ligament (ALL) group than the healed ALL group. However, the risk factor for unhealed ALL remains unknown in literature. Inclusion criteria were patients who underwent hamstring ACL reconstructions within 6 weeks after injury from January 2008 to March 2021. Included patients had concomitant ALL injuries that were confirmed by preoperative magnetic resonance imaging (MRI). Preoperative ALL injury was graded by the Muramatsu classification, and postoperative ALL healing was graded by a modification of the Lee classification (good, partial, and non-visualized). The patients were allocated to an improved group and an unimproved group on the basis of a comparison of pre- and postoperative MRI. Severity of bone contusion was graded as none, minimal, moderate, and severe by the Song classification. 128 patients were included. Preoperatively, 86 (67.2 %) patients had partial ALL tears and 42 (32.8 %) patients had complete tears. Postoperatively, 17 (13.3 %) patients showed "good", 91(71.1 %) showed "partial", and 20 (15.6 %) showed "non-visualized" healing. Thirty-eight (29.7 %) and 90 (70.3 %) patients were allocated to the improved group and unimproved group, respectively. Severity of the bone contusion was a risk factor for "unimproved" ALL (P = 0.015). As the severity of bone contusion increased 1 grade, risk of "unimproved" ALL increased by 1.78 times. Severe bony contusion was associated with poor healing of the ALL following ACL reconstructions.