title: Tibial tunnel placement in anterior cruciate ligament reconstructions and graft impingement.
abstract: Fifty-six anterior cruciate ligament (ACL) reconstructions had a magnetic resonance scan of the ACL graft six months after operation. The impingement-free grafts (n = 26) had a low magnetic resonance signal from origin to insertion. Impinged grafts (n = 30) had an increased magnetic resonance signal confined to the distal two thirds of the graft. The location of the tibial tunnel (TT) was determined from a lateral roentgenogram. Positioning the center of the TT 12-23 mm from the anterior edge of the tibia consistently produced graft impingement and flexion contractures. Roof impingement was avoided and hyperextension was regained when the TT was centered more posteriorly within a 6-mm impingement-free zone (22-28 mm from the anterior edge of the tibia). Stability and knee extension were significantly better when the center of the TT was 2-3 mm posterior to the center of the normal ACL insertion.
authors.affiliation: Department of Orthopedics, David Grant Medical Center, Travis AFB, California.
authors.forename: S M
authors.initials: SM
authors.lastname: Howell
authors.forename: J A
authors.initials: JA
authors.lastname: Clark
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008722:Methods; D011183:Postoperative Complications / Q000517:prevention & control; D013977:Tibia / Q000601:surgery*