title: Nonoperative, dynamic treatment of acute achilles tendon rupture: influence of early weightbearing on biomechanical properties of the plantar flexor muscle-tendon complex-a blinded, randomized, controlled trial.
abstract: Acute Achilles tendon rupture alters the biomechanical properties of the plantar flexor muscle-tendon complex that can affect functional performance and the risk of repeat injury. The purpose of the present study was to compare the biomechanical properties of the plantar flexor muscle-tendon complex in patients randomized to early weightbearing or non-weightbearing in the nonoperative treatment of Achilles tendon rupture. A total of 60 patients were randomized to full weightbearing from day 1 of treatment or non-weightbearing for 6 weeks. After 6 and 12 months, the peak passive torque at 20° dorsiflexion, the stiffness during slow stretching, and the maximal strength were measured in both limbs. The stiffness of the plantar flexor muscle-tendon complex in the terminal part of dorsiflexion was significantly increased (p = .024) in the non-weightbearing group at 12 months. The peak passive torque was significantly lower for the affected limb at 6 months (91%; p = .01), and the stiffness was significantly lower for the affected limb during the early part of dorsiflexion at 6 (67%; p < .001) and 12 (77%; p < .001) months. In conclusion, an increased stiffness of the plantar flexor muscle-tendon complex in the terminal part of dorsiflexion was found in the non-weightbearing group. The altered stiffness and strength in the affected limb could affect the coordination of gait and running.
authors.affiliation: Surgeon, Department of Orthopedics, Clinical Orthopedic Research Hvidovre, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark. Electronic address: kbarfod@dadlnet.dk.
authors.forename: Kristoffer Weisskirchner
authors.initials: KW
authors.lastname: Barfod
authors.affiliation: Gait Analysis Laboratory, Department of Orthopedics, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Bencke
authors.affiliation: Gait Analysis Laboratory, Department of Orthopedics, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.
authors.forename: Hanne Bloch
authors.initials: HB
authors.lastname: Lauridsen
authors.affiliation: Surgeon, Department of Orthopedics, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Dippmann
authors.affiliation: Surgeon, Department of Orthopedics, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Ebskov
authors.affiliation: Professor, Department of Orthopedics, Clinical Orthopedic Research Hvidovre, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Troelsen
mesh_terms: D000125:Achilles Tendon / Q000293:injuries* / Q000503:physiopathology; D000328:Adult; D004434:Early Ambulation; D005081:Exercise Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000503:physiopathology; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D012421:Rupture; D016037:Single-Blind Method; D013708:Tendon Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D016896:Treatment Outcome; D016474:Weight-Bearing / Q000502:physiology*
keywords: Achilles tendon rupture; biomechanical properties; nonoperative treatment; weightbearing