Anterolateral Ligament Injury in Knee Dislocations

Abstract

Purpose: The purpose of this study is to describe the prevalence and associated factors of anterolateral ligament (ALL) injury in knee dislocation (KD).

Methods: A retrospective review of charts and radiological images was done for patients who underwent multiligamentous knee reconstruction surgery for KD in the authors' institution from May 2008 to December 2016. The inclusion criteria were both genders, skeletally mature, and first dislocation. Previous anterior cruciate ligament injury or surgery were the exclusion criteria. Magnetic resonance imaging was used to describe the ALL injury. The association of ALL injury with other variables related to the injury and the patient's background features was examined.

Results: Forty-eight patients (49 knees) were included. The mean age of the patients was 32.3 ± 10.6 years. High-energy trauma was the mechanism of dislocation in 28 (57.1%) knees. Thirty-one knees (63.3%) were classified as KD type IV. Forty-five (91.8%) knees had a complete ALL injury, and 3 (6.1%) knees had incomplete ALL injury. Forty (81.6%) knees had a complete ALL injury at the proximal fibers of the ALL, while 23 (46.9%) knees had complete distal ALL injury. None of the 46 (93.9%) knees with lateral collateral ligament injury had normal proximal ALL fibers (P = .012). Injury to the distal fibers of the ALL, as well as overall ALL injury, was not associated with any other variables (P > .05). Moreover, all patients with associated tibial plateau fractures (9; 18.4%) had abnormality of the proximal fibers of the ALL (P = .033).

Conclusions: ALL injury is highly prevalent among dislocated knees. Most of the injuries are of high grade and involve the proximal, suprameniscal, fibers of the ligament.

Level of evidence: Level IV, retrospective case series with no comparison group.