Genetic Influences on Joint Contractures Secondary to Immobilization

Abstract

The primary research question of this study queries whether, beyond environmental conditions, genetic factors affect the development of joint contractures. We hypothesized that intrinsic genetic factors influence the severity of joint contractures developing secondary to joint immobilization. Forty rats from four inbred rat strains had one leg immobilized in knee flexion for 4 weeks. The contracture was measured mechanically as the lack of range of motion to a standardized torque. Using the contralateral leg as a control, the average severity of the contracture could be calculated and compared between strains. All immobilized legs presented knee contractures after 4 weeks of immobilization. Two strains (Dark Agouti and Fisher 344) showed a larger mean knee contracture than those of the two other rat strains (Augustus Copenhagen Irish and Brown Norway). Environmental factors, such as immobility, are usually identified as a cause of a joint contracture. These results demonstrate that, in addition to mechanical factors in the environment of a joint, intrinsic genetic factors participate in the process leading to joint contracture. This demonstration has important consequences for directing future research and may lead to interventions to help patients at risk of developing joint contractures.

Posttraumatic Elbow Stiffness

“…Forty rats from four inbred rat strains had knee immobilization. The mean contracture observed in two of these strains was significantly greater than that in the other two (p < 0.05), supporting intrinsic genetic factors influencing the severity of joint contractures 46 .…”

Knee Flexion Contractures in Patients with Osteoarthritis: Clinical Features and Histologic Characterization of the Posterior Capsule

“…Genetically, evidence for a predisposition to decreased ROM comes from a study in which different rat strains were subjected to immobilization of the knee joint [30]. Dark Agouti and Fisher 344 strains developed more severe contractures than Augustus Copenhagen Irish and Brown Norway strains.…”

Joint contractures and acquired deforming hypertonia in older people: Which determinants?

“…Characteristic modulation of specific biochemical pathways identified by a temporal gene expression profile during immobilization-induced contracture in rat knees revealed that the joint capsule was sensitive to immobility (Table 2) (73). Along with mechanical factors in the environment of the joint, a study of different inbred rat strains provided evidence that intrinsic genetic factors contribute to the development and susceptibility to joint contractures (74). These experimental results provide insight into molecular changes relevant to the pathophysiology of joint contractures in the context of ADH.…”