Lesions of ligaments

Abstract

Whereas muscles act to produce movement about joints, ligaments stabilize joints and control the degree of movement that takes place. They are capable only of withstanding tensile forces but the anterior longitudinal ligament, for example, has double the tensile strength of the cancellous bone of the vertebral body (Shah, 1976). If a ligament ruptures, movement about the joint is excessive in the directions normally limited by that ligament. Complete rupture of a ligament produces a brief sensation of snapping accompanied by a stab of pain at the time of the injury, but the predominant symptom is loss of function and the ensuing pain may be minimal. For example, surgical disruption of the supraspinous ligament does not lead to the development of low back pain, so Macnab (1977) believes segmental instability is responsible for the symptoms. A sprained ligament is a partial tear which is felt as an immediate pain after lifting or twisting. Usually it is followed by a pain-free interval after which the patient develops stiffness that limits his mobility. The stiffness subsides over a few days.