Purpose: A narrow intercondylar notch width has for decades beenconsidered a predisposing factor for anterior cruciate ligament (ACL)injury, in particular non-contact injury.1,2During side-stepping andcutting the ACL winds around the walls of the intercondylar notchand can become amputated, especially if housed within a narrowernotch. While several researchers have found a relationship betweena narrow intercondylar notch width index (NWI) and ACL injury,3,4some investigators have not.5This study aims to compare the NWI ininjured and uninjured athletes. In particular both anterior and pos-terior notch width indices were measured which is not common in theliterature.Method: Twenty-ﬁve ACL injured patients who had no reconstructivesurgery were recruited from a larger cohort. All patients had a completeACL rupture diagnosed either during arthroscopy, by MRI or on clinicalexamination by an orthopaedic surgeon. Patients over the age of 46were excluded. Patients were matched with 25 uninjured sportspeoplefor age and sporting levels. The injured group comprised 6 femalesand 19 males aged 23 to 46 years old (mean 34). The uninjured groupcomprised 9 females and 16 males aged 21 to 44 years old (mean 32).Patients were radiographed in 4 point kneeling as described by LePrade.5One of the authors attended each session to ensure correctpositioning, constant knee angle and avoidance of femoral rotation.Notch width indices were calculated as described by Soural et al.4Independent t- tests were used to compare NWI between groups.Results: The mean anterior NWI was .199 for the injured group, and.233 for the uninjured group (p < .001). The mean posterior NWI was.276 for the injured group, and .293 for the uninjured group (p = 008).The difference between anterior NW indices reached greater signiﬁ-cance than for posterior NW indices.Conclusion: The signiﬁcant difference found in the NWI betweeninjured and healthy subjects conﬁrms that a narrow NWI may be afactor in the pathogenesis of ACL injuries. Although limited whencompared to CT and MRI we suggest that plain radiographs are aconvenient and inexpensive means whereby valuable information withregard to notch size can be provided. Radiographic screening mayassist in identifying sportspeople at risk of ACL injury.
2015 Royal Australian College of Radiologists' (RANZCR) Annual Scientific Meeting, Adelaide, Australia 29 October - 1 November 2015
Journal of Medical Imaging and Radiation Oncology / Vol. 59, Supplement 1, pp.100