Magnetic resonance imaging appearances of the capsulo-osseous layer of the iliotibial band and femoral attachments of the iliotibial band in the normal and pivot-shift ACL injured knee

Monica Khanna,Chimnay Gupte,Andy Williams,Miny Walker,Alexander Dodds

doi:10.1007/s00256-018-3128-9

Monica Khanna, Chimnay Gupte + Show 3 more

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https://doi.org/10.1007/s00256-018-3128-9

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Abstract

BackgroundBiomechanical evidence suggests that the anterolateral structures of the knee may be important restraints against anterolateral rotatory instability (ALRI) in the setting of anterior cruciate ligament (ACL) injury.ObjectiveTo describe the anatomy and presence of injury of the capsule-osseous layer of the iliotibial band (CITB), the iliotibial band, and its deep distal femoral attachments in patients with a ‘normal’ knee (no pivot-shift bone marrow edema (BME) pattern) and patients with a pivot-shift BME pattern indicative of a pivot-shift injury associated with ACL tears.MethodsGroup 1: 20 consecutive patients with no MRI evidence of pivot-shift injury and group 2: 20 consecutive patients with a pivot-shift BME pattern on MRI were identified. Retrospective consensus analysis of the anatomy and appearances of the CITB and the ‘proximal’ and ‘epicondylar’ distal femoral attachments of the ITB was performed for each MRI by two experienced musculoskeletal radiologists.ResultsThe positive predictive value (PPV) of CITB injury for pivot-shift ACL injury was 74%, negative predicted Value (NPV) was 80%. The PPV for injury of the ‘proximal’ ITB femoral attachment with pivot-shift ACL injury was 93%, NPV was 84%. The PPV for ‘epicondylar’ iliotibial femoral attachment injury was 62%, NPV was 45%.ConclusionsInjury of the CITB and ‘proximal’ deep femoral attachments of the ITB are good markers for ACL injury even in the absence of a Segond fracture and should be evaluated on all MRIs as they may prove important in the further management of ALRI.

Highlights

Pivot-shift BME pattern on MRI is a well-recognized indicator of anterior cruciate ligament (ACL) injury in the acutely injured knee
For the first time to our knowledge, we describe the anatomy of the deepdistal femoral attachments of the ITB as identified on MRI
Group 2 In the pivot-shift BME group, a Segond fracture was not visible in any of the 20 pivot-shift cases, in five cases edema was identified within the lateral tibial rim at the site of the insertion of the capsule-osseous layer of the iliotibial band (CITB), at the expected site of a Segond fracture

Summary

Introduction

Pivot-shift BME pattern on MRI is a well-recognized indicator of ACL injury in the acutely injured knee. Damage to the anterolateral structures of the knee, in particular the part that attaches to the Segond fracture fragment, has been a recent focus of research. Segond first described it in 1879 as a “pearly resistant fibrous band” at the site of the Segond fracture at the anterolateral tibial plateau [1]. Its anatomy, function, and biomechanical importance have been extensively reported with varying nomenclature and anatomical descriptions It has been described as the mid third lateral capsular ligament (MTLCL) [2, 3] anterior oblique band of the fibular collateral ligament (AOB-FCL) [4], the capsulo-osseous layer of the ITB. Biomechanical evidence suggests that the anterolateral structures of the knee may be important restraints against anterolateral rotatory instability (ALRI) in the setting of anterior cruciate ligament (ACL) injury

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