Ultrasonography for Monitoring Healing and Rehabilitation

Soft tissue injuries in the horse require a significant amount of time, effort, and expense to heal. Sequential ultrasound examinations allow the veterinarian guiding the rehabilitation process to critically evaluate the healing structure(s) and to recommend the appropriate therapy and exercise for each stage of healing, thus avoiding additional time and expense due to re-injury or alternatively to advancing in exercise more slowly than necessary. Ultrasound is well suited to multiple examinations because it is a safe, noninvasive, and relatively inexpensive imaging modality that provides an accurate assessment of soft tissue status. Generally, ultrasound examinations at 6- to 8-week intervals after the initial diagnosis are optimal for two reasons. First, this interval allows sufficient time so that, if healing is progressing normally, the horse can move up the next level of exercise intensity. Second, the interval is short enough that, if healing is not proceeding normally, timely changes in treatment and management can be initiated. The first examination generally reveals swelling of the affected tissue and torn fibers. Initial treatment is aimed at reduction of inflammation and protection from further damage with rest. Subsequent examinations should reveal a sequential reduction in size of the affected tendon or ligament, and replacement of the torn fibers with new collagen that is remodeled over time to normal fibers that are properly aligned for maximum strength. Rehabilitation is aimed at providing a smooth increase in tendon load and overall fitness for the horse. The purpose of this chapter is to discuss ultrasound findings and a general rehabilitation program that is optimal at each 6- to 8-week healing interval. For specific therapies for tendon and ligament injury, please refer to other chapters in this issue.