| Segond fracture | |
|---|---|
 | |
| Segond fracture of left knee | |
| Specialty | Orthopedic |
TheSegond fracture is a type ofavulsion fracture (soft tissue structures pulling off fragments of theirbony attachment) from thelateral tibial plateau of theknee, immediately below the articular surface of thetibia (see photo).
Because of the high rate of associated ligamentous and meniscal injury, the presence of a Segond or reverse Segond fracture requires that these otherpathologies must be specifically ruled out. Or more pragmatically, the orthopaedic team assume that the presence of Segond fracture equals ACL rupture, as the correlation is close to 100%. Increasingly, reconstruction of the ACL is combined with reconstruction of the anterolateral ligament when this associated pathology is present.[1][2][3][4] The long-term benefit of an associated Anterolateral Ligament (ALL) reconstruction at the time of ACL surgery is not known. Attention and research is also being paid to a Lateral extra-articular Tenodesis (LET) instead of ALL.[citation needed]
Segond and reverse Segond fractures are characterized by a small avulsion,[5] or "chip", fragment of characteristic size that is best seen on plainradiography in theanterior-posterior plane. The avulsed fragment of bone may be very difficult to see on the plainx-ray exam, and may be better seen oncomputed tomography.MRI may be useful for visualization of the associatedbone marrow edema of the underlying tibial plateau on fat-saturated T2W and STIR images, as well as the associated findings of ligamentous and/or meniscal injury.[citation needed]
Originally described by Dr.Paul Segond in 1879[6][7] after a series ofcadaveric experiments, the Segond fracture occurs in association with tears of theanterior cruciate ligament (ACL) (75–100%) and injury to themedial meniscus (66–75%), lateral capsular ligament (now known as the Anterolateral ligament, or ALL), as well as injury to the structures behind the knee.[citation needed]
A rare, mirror image of the Segond fracture has also been described. The so-called "reverse Segond fracture" can occur after an avulsion fracture of the tibial component of the medial collateral ligament (MCL) in association with posterior cruciate ligament (PCL) and medial meniscal tears.[8][9]
Segond fracture is typically the result of abnormal varus, or "bowing", stress to the knee, combined with internal rotation of the tibia. Reverse Segond fracture, as its name suggests, is caused by abnormal valgus, or "knock-knee", stress and external rotation.[citation needed]
Originally thought to be a result of avulsion of the medial third of the lateral collateral ligament, the Segond fracture has been shown by more recent research to relate also to the insertion of the iliotibial tract (ITT) and the anterior oblique band (AOB), aligamentous attachment of thefibular collateral ligament (FCL), to the midportion of the lateral tibia and to be associated with avulsion by the anterolateral ligament (ALL).[10]