Suturing versus immobilization of a muscle laceration - A morphological and functional study in a mouse model

Muscle laceration remains a difficult problem for orthopaedic surgeons. Des pite many studies related to the muscle's ability to regenerate after muscl e degeneration, very few reports are available regarding structural and fun ctional recovery after skeletal muscle laceration. We developed an animal m odel of muscle laceration in mice, where the gastrocnemius muscles were rep roducibly transected. We compared the effect of a surgical repair versus a short period of immobilization (5 days) on the muscle healing. The natural course of muscle recovery was monitored at several points after injury usin g histologic, immunohistochemical, and functional testing. In the injured m uscle, we observed a high number of regenerating myofibers and development of fibrotic scar tissue. Suturing the lacerated muscle immediately after in jury promoted better healing of the injured muscle and prevented the develo pment of deep scar tissue in the lacerated muscle; conversely, immobilizati on resulted in slower muscle regeneration and the development of a large ar ea of scar tissue. Tetanus strength 1 month after injury was 81% of control muscles for the sutured muscles, 35% for the lacerated muscles with no tre atment, and 18% for the immobilized muscles. Based on this study, suturing a muscle laceration with a modified Kessler stitch results in the best morp hologic and functional healing.