Abstract
BackgroundThe goal of this present study was to precisely determine the dimension and location of the impaction fracture on the lateral femoral condyle in patients with an ACL rupture.MethodsAll patients with post-injury bi-plane radiographs and MRI images after sustaining a tear to the anterior cruciate ligament were included. Lateral radiographs of the affected knee were inspected for a lateral femoral notch sign. MRIs of patients with a lateral condylopatellar sulcus ≥1.5 mm were used to segment and measure the lateral condylopatellar sulcus. The MRI examination was interpreted by an expert in musculoskeletal radiology. The study was approved by the ethics committee of the state of Salzburg.ResultsA “lateral femoral notch sign”was seen in 50 patients. The average total surface area of the lateral femoral condyle was 3271.7 mm2 (SD 739.5 mm2). The defect had a mean surface area of 266.1 mm2 (SD 125.5 mm2), a mean volume of 456.5 mm3 (SD 278.5 mm3), a mean depth of 3.0 mm (SD 0.8 mm). On average 169 mm2 (SD 99.6 mm2) of the surface of the condyle were affected by the impaction fracture which corresponds to 5.2 % (SD 2.8 %) of the surface of the lateral femoral condyle. In 51 % the impaction fracture was located in the central-external area of the femoral condyle.ConclusionsIn cases of a clinically suspected ACL rupture lateral radiographs of the knee should be checked for a lateral femoral notch sign further MRI for confirmation should be performed. Knowing of the precise defect on the lateral femoral condyle is an additionally valuable information, as concomitant injuries to a rupture of the anterior cruciate ligament increase the risk for early-onset osteoarthritis in the future.
Highlights
The goal of this present study was to precisely determine the dimension and location of the impaction fracture on the lateral femoral condyle in patients with an anterior cruciate ligament (ACL) rupture
It is known that 80–85 % of all osseous injuries observed in the knee after a tear of the anterior cruciate ligament (ACL) are found in the lateral compartment [1,2,3]
The authors concluded that a sulcus depth exceeding 1.5 mm which corresponds to a standard deviation 3 times above the norm could be considered as a reliable indicator of an ACL rupture, a cut-off, which was chosen in this investigation to define patients for further investigation of their magnetic resonance imaging (MRI) [8]
Summary
The goal of this present study was to precisely determine the dimension and location of the impaction fracture on the lateral femoral condyle in patients with an ACL rupture. The injury mechanism that leads to an ACL tear involves an anterior subluxation of the tibia in relation to the femur This can provoke a collision between the lateral femoral condyle and the postero-lateral edge of the tibial plateau, [4, 5] which may result in a “kissing contusion”. Speer et al investigated sagittal and coronal MRIs in order to define the precise localization of the impaction fracture on the lateral femoral condyle They reported that the lesions were predominantly located in the area of the sulcus terminalis and obviously would tend to be located laterally rather than medially [15]. The goal of this present study was to precisely determine the size and location of impaction fractures on the lateral femoral condyle (“lateral femoral notch sign”) in patients with an ACL rupture
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
