Segond fracture

Clinical History

Swollen and tender left knee after a fall while skiing.

Imaging Findings

The patient sustained twisting injury to the left knee during a fall while skiing. The knee immediately became swollen and painful. Initial radiograph of the knee showed a subtle avulsion fracture of the left tibia just distal to the lateral tibial plateau and joint effusion. Patient was referred to fracture clinic the following week. On clinical examination, Orthopaedic surgeon suspected an ACL tear and sent the patient for MRI scan of the left knee. Subsequently arthroscopy was performed, which confirmed the full thickness ACL tear.

Discussion

The Segond fracture is a subtle vertical avulsion fracture involving the proximal tibia immediately distal to the lateral plateau. The mechanism of injury is internal rotation and varus stress, which commonly believed to cause abnormal tension on the central portion of the lateral capsular ligament. However, Campos et al have proposed that stresses transmitted via the Iliotibial Tract and the Anterior Oblique Band of the fibular collateral ligament are relevant in the pathogenesis. The importance of a Segond fracture is that it is commonly associated with meniscoligamentous injury, namely:
·Tear of the anterior cruciate ligament (75-100%).
·Menisci Injuries(66-70%).
·Avulsion fracture of the Gerdy tubercle.

At routine radiography, the avulsed cortical fragment is best seen on the straight anteroposterior view of the knee. By using magnetic resonance ( MRI ) imaging, marrow oedema is seen at the site of the avulsed cortical fragment, but the low signal fragment may be very difficult to appreciate.

Differential Diagnosis List

Final Diagnosis

Segond Fracture

URL:	https://www.eurorad.org/case/2666
DOI:	10.1594/EURORAD/CASE.2666
ISSN:	1563-4086