Open Repair of an Acute Latissimus Tendon Avulsion in a Major League Baseball Pitcher
Latissimus Dorsi (LD) Avulsion Injuries
Latissimus dorsi (LD) avulsion injuries are rare injuries most commonly diagnosed in competitive athletes. The LD muscle originates from the thoracic spine, thoracolumbar fascia, and iliac crest, converging toward the axilla to insert between the pectoralis major and teres major tendons, just medial to the bicipital groove of the proximal humerus. Functionally, the latissimus adducts, internally rotates, and extends the humerus. It also acts to depress the arm against resistance, compress the inferior scapula when the arm is elevated, and pull the trunk upward and forward when the arms are fixed.
Latissimus Dorsi Pathology in Baseball Pitchers
In pitchers, the LD exerts minimal activity during the wind-up and early cocking phase of the pitching cycle, increases its activity during the late cocking phase, exerts maximum tension during the acceleration phase, and remains active but relaxes during deceleration and follow-through. Importantly, the LD is relatively more active on electromyography during the acceleration phase of the pitching cycle in professional baseball pitchers compared with nonprofessional and recreational throwers, possibly predisposing professional pitchers to LD injuries.
To date, only 11 case reports have been published in the literature discussing the presentation and management of these injuries. Most cases of acute rupture have been reported in competitive athletes, ranging from steer wrestlers and water skiers to rock climbers and professional baseball pitchers. For noncompetitive or recreational athletes, nonoperative treatment of LD avulsions will most likely result in satisfactory outcomes because the shoulder compensates for loss of LD strength and function via increased activity in synergistic muscle units. One recent case series supports the use of nonoperative treatment in the management of LD and teres major (TM) injuries in professional baseball pitchers.
Treatment of Latissimus Dorsi in MLP Pitcher
However, in throwing athletes with LD avulsion injuries associated with significant tendon retraction, primary surgical repair may offer the benefits of successful return to sport at a high functional capacity with minimal, if any, strength deficits postoperatively. One case of a professional baseball player with a latissimus rupture treated operatively has been published, but no details of the case are available. In this report, we present a professional Major League Baseball player with an acute LD tendon rupture, with subsequent primary anatomic repair of tendon to bone.