title: Anatomical two-bundle versus Rosenberg's isometric bi-socket ACL reconstruction: a biomechanical comparison in laxity match pretension.
abstract: It is not well known how much tension should be applied to ACL graft at the time of graft fixation. As a step to determine the optimal initial tension, it is indispensable to know the graft tension to restore normal anterior-posterior (A-P) laxity (laxity match pretension, LMP). The objective was to determine the LMP in ACL reconstruction for the anatomical two-bundle technique and for the Rosenberg's isometric bi-socket one, and to compare these two techniques in LMP. Twenty-four patients with unilateral chronic ACL insufficiency were divided into the following two groups. The anatomical two-bundle technique was performed on 12 patients via two femoral tunnels at 9 and 10 o'clock or 2 and 3 o'clock on the posterior margin of the notch and two tibial tunnels (Group A), while the Rosenberg's isometric bi-socket reconstruction was performed on the remaining 12 patients through two femoral tunnels at 10 and 11 o'clock or 1 and 2 o'clock and one wider tibial tunnel (Group B). After two doubled semitendinosus grafts were fixed with two EndoButton-CL s on the femur, they were temporarily fixed to the tension-adjustable force gauge on the tibia, respectively. The total tension applied to grafts was set at 10, 20, 30, 40, or 50 N at 20 degrees of knee flexion, and the A-P laxity was measured by applying A-P drawer load of 134 N at 20 degrees of flexion. By comparing the measured laxity with that for the opposite healthy knee, the tension to restore the normal A-P laxity (LMP) was estimated. The mean LMP of 7.3 N in Group A was significantly smaller than that of 25.8 N in Group B. The anatomical two-bundle technique makes it possible to more effectively restore A-P stability with lower initial tension than the isometric Rosenberg's bi-socket reconstruction.
authors.affiliation: Department of Sports Medicine, Osaka Kousei-Nenkin Hospital, 4-2-78, Fukushima-ku, Fukushima, Osaka, 553-003, Japan. ta-mae@umin.ac.jp
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Mae
authors.forename: Konsei
authors.initials: K
authors.lastname: Shino
authors.forename: Norinao
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hamada
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoneda
authors.forename: Ken
authors.initials: K
authors.lastname: Nakata
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000503:physiopathology* / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001182:Arthroscopy; D001696:Biomechanical Phenomena; D005260:Female; D005269:Femur / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D019651:Plastic Surgery Procedures / Q000379:methods*; D018709:Statistics, Nonparametric; D013709:Tendon Transfer; D013977:Tibia / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome