33A1   Extraarticular fracture, avulsion

These fractures can result from medium to moderate injury to the knee. Twisting injuries to the knee may result in major disruptions of the medial collateral, anterior cruciate, or posterior cruciate ligaments. It is most commonly the medial collateral and the anterior cruciate ligament that are injured. Patients with an anterior cruciate ligament injury will sometimes report a popping sensation from the knee at the time of injury. A rapid early hemarthrosis will occur with an anterior cruciate ligament injury. Anterior cruciate ligament injuries most commonly occur in young patients who engage in sporting activities.

Small avulsion fractures may be part of more complex injuries to the knee, such as multiligamentous knee dislocation. MRI can detect associated ligament damage. Consultation with and advice from specialist knee reconstructive surgeons may be needed.

Avulsion of the lateral collateral ligament from the distal femur is known as the “Segond” fracture. “Segond” fractures may be accompanied by serious ligament injuries to the knee. There may also be peroneal nerve, or meniscal, injuries.

X-ray taken from Orozco R et al, (1998) Atlas of Internal Fixation. Used with kind permission.

Avulsion of the medial collateral ligament from the femur may result in calcification of this ligament after several years (the so called “Pellegrini-Stieda” lesion).

Avulsion of the lateral collateral ligament from the distal femur is known as the “Segond” fracture. “Segond” fractures may be accompanied by serious ligament injuries to the knee. There may also be peroneal nerve, or meniscal, injuries.