Segond tibial condyle fracture: Lateral capsular ligament
Common posterolateral corner injuries include an arcuate fracture (a tearing away of the fibula at the point where the arcuate ligament attaches to the knee) and a Segond fracture (a tearing away of the meniscotibial part of the lateral capsular ligament
Ligaments Cross-sectional area ([mm.sup.2]) Posterior longitudinal ligament (PLL) 20.0 Anterior longitudinal ligament (ALL) 63.7 Ligamentum flavum (LF) 40.0 Capsular ligament
(CL) 30.0 Intertransverse ligament (ITL) 1.8 Interspinous ligament (ISL) 40.0 Supraspinous ligament (SSL) 30.0 TABLE 2: Material properties of the components in the osseoligamentous lumbar spine model.
The fracture is caused by avulsion of the meniscotibial portion of the middle third of the lateral capsular ligament
, with possible associated fractures of the fibular head or Gerdy's tubercle.
The medial collateral ligament is classified as an accessory ligament because it is in a position free from the joint within the articular capsule, in agreement with the classification of Benjamin & Ralphs, and therefore can be classified as a capsular ligament
These include the middle third of the capsular ligament
, the lateral head of the gastrocnemius tendon, the lateral meniscus, and the posterolateral joint capsule.