title: The biceps femoris muscle complex at the knee. Its anatomy and injury patterns associated with acute anterolateral-anteromedial rotatory instability.
abstract: We dissected 30 cadaveric knees to provide a detailed anatomic description of the biceps femoris muscle complex at the knee. The main components of the long head of the muscle are a reflected arm, a direct arm, an anterior arm, and a lateral and an anterior aponeurosis. The main components of the short head of the biceps femoris muscle are a proximal attachment to the long head's tendon, a capsular arm, a confluens of the biceps and the capsuloosseous layer of the iliotibial tract, a direct arm, an anterior arm, and a lateral aponeurosis. We examined 82 consecutive, acutely injured knees with clinical signs of anterolateral-anteromedial rotatory instability for the incidence and anatomic location of injuries to the biceps femoris muscle. Injuries to components of that muscle were identified in 59 (72%) of these knees; 29 knees (35.4%) had multiple components injured. There were 3 injuries to the long head of the biceps femoris muscle (all in the reflected arm) and 89 to the short head. A statistically significant correlation (P = 0.01) was found between increased anterior translation with the knee at 25 degrees of flexion as demonstrated by the Lachman test and injury to the biceps-capsuloosseous iliotibial tract confluens. Additionally, adduction laxity at 30 degrees of flexion correlated with a Segond fracture (P = 0.04). These data establish, in part, the relationship of the biceps femoris complex injury to anterior translation instability.
authors.affiliation: Hughston Clinic, PC, Columbus, Georgia 31908-9517, USA.
authors.forename: G C
authors.initials: GC
authors.lastname: Terry
authors.forename: R F
authors.initials: RF
authors.lastname: LaPrade
mesh_terms: D000293:Adolescent; D000328:Adult; D005205:Fascia / Q000033:anatomy & histology / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D007718:Knee Injuries / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D007719:Knee Joint / Q000033:anatomy & histology* / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000293:injuries* / Q000294:innervation / Q000503:physiopathology / Q000601:surgery; D010543:Peroneal Nerve / Q000033:anatomy & histology; D012399:Rotation; D012421:Rupture; D013710:Tendons / Q000033:anatomy & histology / Q000473:pathology / Q000503:physiopathology