Segond fracture

Clinical History

Twisting injury sustained playing football.

Imaging Findings

This patient twisted his knee whilst playing football. This resulted in pain and moderate amount of swelling over the lateral aspect of his knee immediately after the incident. He had a fixed flexion of 30 degrees. Plain radiograph taken showed an avulsion type fracture of the lateral tibia plateau. Testing his anterior cruciate ligament revealed slight anteroposterior laxity. Knee extension improved after 2 weeks but has a 5 degrees block to full extension. Arthroscopy 1 month after the injury revealed midsubstance tear to his anterior cruciate ligament but no meniscal injury. He was treated conservatively with physiotherapy.

Discussion

Segond fracture was originally described by Dr. Paul Segond in 1879 as a small cortical avulsion fracture off the lateral tibial plateau at the insertion of the midportion of the lateral collateral ligament. A variant of the fracture, an avulsion of the fibula was later recognised. Both these are associated with ACL tears. The pathogenesis is linked to the attachment of the ilio-tibial band fibres and anterior oblique band of the fibular collateral ligament to the avulsed fragment. The fracture occurs by forced internal tibial rotation with the knee flexed and is nearly always a sporting injury. This mechanism placed tremendous force on the mid portion of the lateral capsule and associated meniscotibial ligament resulting in a small bony avulsion. The association with an anterior cruciate ligament injury has been reported as almost 100%. Other reported associated injuries include meniscal injuries and damage to posterolateral corner of the knee. Investigation consists of plain radiograph and MRI scan. The treatment for the Segond fracture is generally conservative in the undisplaced fractures and repair of the ACL injury is indicated for athletic individual wishing to return their level of activity. The Segond fracture is an important radiographic sign that is critical to recognize because it is generally associated with anterior cruciate ligament disruption. This phenomenon, which is easy to detect by radiograph, can thus be regarded as a strong indication of the presence of a ligament injury.

Differential Diagnosis List

Final Diagnosis

Segond fracture

URL:	https://www.eurorad.org/case/4967
DOI:	10.1594/EURORAD/CASE.4967
ISSN:	1563-4086