Posterolateral corner injuries of the knee

Abstract

We retrospectively reviewed the hospital records of 68 patients who had been referred with an injury to the posterolateral corner of the knee to a specialist knee surgeon between 2005 and 2009. These injuries were diagnosed based on a combination of clinical testing and imaging and arthroscopy when available. In all, 51 patients (75%) presented within 24 hours of their injury with a mean presentation at eight days (0 to 20) after the injury. A total of 63 patients (93%) had instability of the knee at presentation. There was a mean delay to the diagnosis of injury to the posterolateral corner of 30 months (0 to 420) from the time of injury. In all, the injuries in 49 patients (72%) were not identified at the time of the initial presentation, with the injury to the posterolateral corner only recognised in those patients who had severe multiple ligamentous injuries. The correct diagnosis, including injury to the posterolateral corner, had only been made in 34 patients (50%) at time of referral to a specialist knee clinic. MRI correctly identified 14 of 15 injuries when performed acutely (within 12 weeks of injury), but this was the case in only four of 15 patients in whom it was performed more than 12 weeks after the injury. Our study highlights a need for greater diligence in the examination and investigation of acute ligamentous injuries at the knee with symptoms of instability, in order to avoid failure to identify the true extent of the injury at the time when anatomical repair is most straightforward.

Description of the Posterolateral Rotatory Drawer Maneuver for the Identification of Posterolateral Corner Injury

“…Despite this, however, 50% of these injuries are not properly diagnosed until the patients are referred to a knee specialist. 18 The previously mentioned findings are corroborated by several articles showing the difficulty of diagnosis by physical examination. Veltri et al 21 suggest a lack of accuracy in the external rotation test at 30 of knee flexion for diagnosing PLC and ACL injuries.…”

“…The difficulty increases significantly when central pivot and medial collateral ligament injuries are involved. 18 Thus the objective of this study is to describe a physical examination maneuver for better evaluation of PLC lesions, attempting to isolate their instability from that of other associated injuries.…”

MRI injury patterns in surgically confirmed and reconstructed posterolateral corner knee injuries

“…Of the FCL, PT, and BF (considered larger structures), at least two were abnormal in all 22 injury cases. Of the PFL, AL, and FFL supports nonoperative management of low-grade injury [18]; however, more significant PLC injury and multiple ligament injuries require operative intervention to avoid poor outcomes [11,12]. For example, one study on the natural history of PLC injuries treated nonoperatively determined that those with significant, grade III disruptions of the lateral ligament complex suffered from a multitude of complications at 8-year follow-up, including persistent posterolateral rotatory instability, muscle weakness, and secondary osteoarthritis [10].…”

Can Stress Radiography of the Knee Help Characterize Posterolateral Corner Injury?

“…The anatomic complexity, variability, and oblique orientation of its individual structures make it difficult to reliably identify all major PLC injuries on conventional MRI sequences [1,2,23,32]. The diagnostic specificity of MRI for knee ligament injury decreases when more than one ligament is injured [26], as is usually the case with PLC injury [24], and chronic injuries may not be well demonstrated [22]. As a static study, MRI also has inherent limitations for diagnosing clinically relevant instability, and partial tears or edema revealed on MRI may not correlate with laxity [32].…”