Skeletally immature (growing) athletes are susceptible to unique elbow injuries that occur as a result of repetitive throwing. These pediatric elbow injuries are common and are often caused by stressing the joint too much, too frequently, or with poor technique. Injury can occur to the growing bone and to articular cartilage, as well as to the muscles, tendons, and nerves.

The weak link in a skeletally immature bone is the growth plate, or growth center (Fig. 1), that part of the bone where growth occurs and, consequently, a frequent site of chronic overuse injury. Injury to the growth center can cause pain, deformity, or shortening. The term Little League elbow, somewhat generalized and overused, is applied to many different types of elbow injuries and diagnoses.

Medial elbow injuries
The medial (inside) aspect of the elbow is subjected to tremendous force in baseball (Fig. 2). During the throwing motion, tension develops over the medial aspect of the elbow, often causing pain and injury. The growth plate on the medial side can experience a spectrum of injuries, ranging from stress fractures to complete fracture with avulsion (the tearing away of a part of bone from its attachment point) and displacement of the bone. Young throwers often experience decreased throwing performance, usually followed by pain and swelling of the elbow and an inability to completely straighten the joint. In addition, the patient may experience tenderness on the inside of the elbow. Symptoms may be exacerbated by continued throwing. X-rays can reveal widening of the growth plate or complete avulsion with separation. Because every child is at his or her own unique stage in growth and development, x-rays of the uninvolved elbow should always be obtained for comparison.

Conservative treatment for medial elbow growth plate injuries includes rest, immobilization, and reconditioning with a gradual return to throwing. Surgery may be necessary for significantly displaced bone fragments.

Osteochondritis dissecans
Repetitive throwing causes compressive forces on the lateral (outside) aspect of the elbow, which, over time, may compromise the blood supply to the articular cartilage and underlying bone. Known as osteochondritis dissecans, this condition is usually seen in 10- to 14-year-old patients. The patient typically complains of pain on the outside of the elbow. Loss of motion, particularly when the elbow is being extended, is also common. Swelling and locking of the joint may also occur. X-rays will usually show the area in question and can assist in the diagnosis. Conservative treatment, to include cessation of sports, immobilization, maintenance and regaining of range of motion, is indicated if the involved segment of bone remains in its normal location and there are no other signs of loose particles within the joint. Surgery, however, may be indicated if (1) loose particles exist within the joint, (2) the involved bone segment has separated, or (3) conservative treatment has failed. Most patients can expect a full return to activity.

Avulsion and stress fractures
The posterior (back) aspect of the elbow is also subjected to significantly increased forces during throwing and, like the medial side of the elbow, can experience injuries ranging from stress fractures to avulsion fractures. The patient may experience pain in the back of the elbow as well as increased discomfort when attempting to extend the elbow against force. X-rays show changes, particularly a widening or fragmentation of the growth center (Fig. 3). Treatment consists of immobilization until the pain and tenderness have resolved. If, however, the fracture fragment has shifted away from the bone, surgery may be required to replace it.

Prevention is the key to protecting young, throwing athletes. Educating the athlete as well as coaches and parents is critical. Proper training with respect to technique and limiting the number of pitches per week should be encouraged.

David C. Rehak, MD
Columbus, Georgia

Further Reading:

• Hutchinson M, Ireland M. Overuse and throwing injuries in the skeletally immature athlete. American Academy Orthopaedic Surgery Instructional Course Lectures. 2003;52:25-36.
• DeSalva E, Williams J, Fidelly P, Holsten M, Urledge M. Pediatric throwing injuries about the elbow. The American Journal of Orthopaedics. 1998;(Feb): 90-96.