title: Quantitative and temporal differential recovery of articular and muscular limitations of knee joint contractures; results in a rat model.
abstract: Joint contractures alter the mechanical properties of articular and muscular structures. Reversibility of a contracture depends on the restoration of the elasticity of both structures. We determined the differential contribution of articular and muscular structures to knee flexion contractures during spontaneous recovery. Rats (250, divided into 24 groups) had one knee joint surgically fixed in flexion for six different durations, from 1 to 32 wk, creating joint contractures of various severities. After the fixation was removed, the animals were left to spontaneously recover for 1 to 48 wk. After the recovery periods, animals were killed and the knee extension was measured before and after division of the transarticular posterior muscles using a motorized arthrometer. No articular limitation had developed in contracture of recent onset (≤2 wk of fixation, P > 0.05); muscular limitations were responsible for the majority of the contracture (34 ± 8° and 38 ± 6°, respectively; both P < 0.05). Recovery for 1 and 8 wk reversed the muscular limitation of contractures of recent onset (1 and 2 wk of fixation, respectively). Long-lasting contractures (≥4 wk of fixation) presented articular limitations, irreversible in all 12 durations of recovery compared with controls (all 12 P < 0.05). Knee flexion contractures of recent onset were primarily due to muscular structures, and they were reversible during spontaneous recovery. Long-lasting contractures were primarily due to articular structures and were irreversible. Comprehensive temporal and quantitative data on the differential reversibility of mechanically significant alterations in articular and muscular structures represent novel evidence on which to base clinical practice.
authors.affiliation: Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada; Bone and Joint Research Laboratory, University of Ottawa, Ottawa, Ontario, Canada;
authors.forename: Guy
authors.initials: G
authors.lastname: Trudel
authors.affiliation: Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada;
authors.forename: Odette
authors.initials: O
authors.lastname: Laneuville
authors.affiliation: Bone and Joint Research Laboratory, University of Ottawa, Ottawa, Ontario, Canada;
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Coletta
authors.affiliation: Biomedical Engineering, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada; and.
authors.forename: Louis
authors.initials: L
authors.lastname: Goudreau
authors.affiliation: Bone and Joint Research Laboratory, University of Ottawa, Ottawa, Ontario, Canada; Division of Orthopedic Surgery, Department of Surgery, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Hans K
authors.initials: HK
authors.lastname: Uhthoff
mesh_terms: D000818:Animals; D003286:Contracture / Q000503:physiopathology*; D004195:Disease Models, Animal; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology*
keywords: contracture; immobilization; joint capsule; knee; muscle; rehabilitation