title: The "N + 7 rule" for tibial tunnel placement in endoscopic anterior cruciate ligament reconstruction.
abstract: Tibial tunnel placement during endoscopic anterior cruciate ligament (ACL) reconstruction has received increased emphasis in the recent literature. Appropriate tunnel length is a critical technical consideration. A tunnel that is too short results in graft extrusion, necessitating supplemental fixation techniques. A tunnel that is too long may make distal fixation and femoral tunnel placement difficult. A simple rule is proposed that allows for correct tunnel length and allows placement of the bone plug consistently within the tibial tunnel, allowing interference screw fixation.
authors.affiliation: Uniformed Services University of the Health Sciences, and the United States Air Force Academy, Colorado Springs 80921, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Miller
authors.forename: D T
authors.initials: DT
authors.lastname: Hinkin
mesh_terms: D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D020679:Arthroscopes; D001696:Biomechanical Phenomena; D001863:Bone Screws; D016025:Bone Transplantation / Q000295:instrumentation; D019723:Endoscopes; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D016059:Range of Motion, Articular / Q000502:physiology; D013709:Tendon Transfer / Q000295:instrumentation; D013977:Tibia / Q000601:surgery*