ABSTRACT
Objective To identify the incidence of the anteromedial impingement fracture of tibial plateau in the posterolateral corner injuries,and to confirm the relationship between the extent of the anteromedial tibial impingement fracture and the severity of the posterolateral instability of the knee joint.Methods The radiographic images of the posterolateral corner injuries were reviewed retrospectively to identify the incidence of the anteromedial impingement fracture of the tibial plateau.A matched group of the posterolateral corner injury patients without the anteromedial impingement fracture was compared with the anteromedial impingement fracture group for the posterior instability and varus instability.And the anteromedial impingement fracture group was subdivided into a marginal fracture group and a compression fracture group based on the size of the fracture,and the posterior instability and medial instability were compared between the two groups.Results From January 2007 to January 2017,there were 266 patients with posterolateral corner injuries admitted,with 19 (7.1％) combined with the anteromedial impingement fractures of the tibial plateau.The posterior instability was significantly severer in the fracture group than the control group (P=0.030),while there were no significant differences in the varus instability between them (P=0.800).Similarly,the posterior instability was significantly severer in the marginal group compared to the compression group (P=0.026),but without significant differences in the varus instability (P=0.397).However,the compression fracture group had a higher risk to have neurovascular injuries (of the popliteal artery and the common peroneal nerve) compared with the marginal fracture group.Conclusion The incidence of the anteromedial impingement fracture of the tibial plateau in posterolateral corner injuries was 7.1％.The anteromedial impingement fracture of the tibial plateau may indicate more severe posterior instability,and a compression fracture may suggest more severe posterior instability compared with the marginal fracture.If there is a compression type fracture,the neurovascular status must be carefully evaluated in addition to the examination of the posterolateral and posterior instability.
ABSTRACT
PURPOSE: The purpose of this study is to elucidate the clinical features of the acute lateral ligamentous complex injuries and evaluate the postoperative results. MATERIALS AND METHODS: Between 1991 and 1997, 27 patients (28 cases) were treated surgically for acute lateral ligament complex injuries. All cases showed 2+ or more varus instability and were treated within 6 weeks after trauma. 20 cases combined other ligamentous injuries and 8 cases had isolated injuries. Among the lateral ligament complex the lateral collateral ligament was ruptured in all cases. Meniscal injuries were associated in 12 cases and 5 cases showed common peroneal nerve injury but no cases showed vascular injuries. RESULTS: On Telos stress X-ray, the varus stability was improved from 2,12+(mean 8.6mm) to 0.50+(mean 2.8mm) in isolated injuries and from 2.95+(mean 9.5mm) to 1.10+(4.5mm) in combined injuries. Cases with isolated injury showed no C and D grade on IKDC subjective evaluation, ligament evaluation and range of motion evaluation. Cases of combined injuries showed 5C and 3D on subjective evaluation, 3C and 2D on ligament evaluation, 3C and 1D on range of motion evaluation. Most common postoperative complication was joint stiffness, of which 2 cases were treated with arthroscopic adhesiolysis. CONCLUSION: Prognosis in isolated cases was good and the results were influenced with combined injuries. To reduce postoperative complications a secure fixation and early rehabilitation was recommended. Our study supports the notion that operation performed at an early stage in fresh injuries with a varus instability of 2+ or more gives improved stability as a final result.