Segond fracture is a type of the lateral condyle of the tibia, immediately beyond its articular surface. It is a type of avulsion fracture. An avulsion fracture is a fracture that occurs due to soft tissue pull on the bone resulting in breakage of the chip of bone.
In most of the cases, Segond fracture is associated with anterior cruciate ligament tear [75%].
It has been related to the insertion of the iliotibial tract and the anterior oblique band [a ligamentous attachment of the fibular collateral ligament to the mid part of the lateral tibia], the anterolateral ligament (lateral capsular ligament) and medial meniscus injury.
This fracture was originally described by Dr. Paul Segond in 1879, based on cadaveric experiments.
The Segond fracture is typically a result of abnormal varus force on the knee.
A reverse Segond fracture has also been described. It is a rare, mirror image of the Segond fracture.
It occurs due to an avulsion fracture of the tibial component of the medial collateral ligament and also is noted in association with posterior cruciate ligament and medial meniscal tears.
Reverse Segond fracture, as its name suggests, is caused by abnormal valgus stress on the knee and external rotation.
Segond and reverse Segond fractures become significant because the associated injuries need to be ruled out if it is seen on x-ray.
It usually occurs as a result of internal rotation and varus stress which can occur in falls and sports injuries.
A curvilinear or elliptic bone fragment projected parallel to the lateral aspect of the tibial plateau is seen on the anteroposterior view of the knee. [ lateral capsular sign].
In case of reverse Segond fracture, the lesion would be seen on medial tibial condyle.
The lesion may be very small to see on the x-ray and CT may be done for better visualization.
MRI may be useful for the underlying tibial plateau on fat- saturated T2W and STIR images, as well as
MRI becomes essential in all cases of Segond fracture to identify internal derangement [the associated findings of ligamentous and/or meniscal injury.]
Associated injuries pattern include
- ACL tear [75%]
- Medial or lateral meniscal tear [66-75% of cases]
- posterior horn most common
- ACL avulsion from the tibial attachment[ rare]
- Avulsion of fibular attachment of the long head of biceps femoris
- Avulsion of the fibular collateral ligament
Treatment of Segond Fracture
It depends on the associated injury and often may require surgical intervention. The choice of following conservative or surgical treatment depends on the laxity of the knee, the functional instability, and on the demands of activities that will be engaged in.