The windswept knee injury is caused by high-energy trauma, which is frequently accompanied by multiple injuries, so obtaining optimal treatment outcome is challenging.
‘Windswept knee injury’ refers to the condition with medial collateral ligament (MCL) injury in one knee caused by valgus force and lateral collateral ligament (LCL) injury in the other knee caused by varus force, which is rarely reported in the literature. We sought to demonstrate the clinical feature of the patients with the windswept knee injury.
Sixteen-patients with the windswept knee injuries who were treated and followed up at least one year in a level one trauma center between 2007 and 2016 were retrospectively reviewed. The injury mechanism, incidence of concurrent cruciate ligament injury or fractures, and vital organ injuries were investigated. Mediolateral stability was evaluated using the valgus and varus stress radiograph. The functional outcome was evaluated using the Lysholm score, Tegner activity score, return to sports rate and the patient’s satisfaction visual analog scale (VAS, 0 -10).
The majority (70%) of the injury mechanism was the pedestrian traffic accident. Fractures were frequently combined both in the knees (44%) and elsewhere (69%). Majority of the patients had concurrent vital organ injuries, such as in the brain, thorax, and abdomen. Concurrent cruciate ligament injury was highly prevalent both in the MCL-injured side (100%) and the LCL-injured side (63%). Mean side-to-side difference on the stress radiograph at 30º of knee flexion was 2.3 ± 1.9mm for valgus stress and 2.2 ± 1.9mm for varus stress. MCL-injured side showed a tendency of less favorable clinical outcome than the LCL-injured side: 67.7 ± 20.1 vs. 77.9 ± 21.2, p = 0.096 for Lysholm score; 5.1 ± 3.1 vs. 6.0 ± 3.1, p < 0.001 for satisfaction VAS. Tegner activity score was only 2.9 postoperatively. The rate of the return to any sports was 43%, but the competing sports were not possible in any patients.
The windswept knee injury is caused by high-energy trauma, which is frequently accompanied by multiple injuries in the knee and/or another site of the body, so obtaining optimal treatment outcome is challenging. The clinical feature of this specific type of injury should be considered during the initial evaluation of the patients and the patients counseling.