Chronic microtrauma to the tibial tuberosity secondary to overuse of the quadriceps muscle is a leading theory. Histologic studies support a traumatic etiology. Laboratory evaluation is not indicated unless other diagnoses are being entertained. The OS lesion is best seen on the lateral view with the knee in slight internal rotation. Not all patients with OS disease need radiographs since the diagnosis is primarily clinical.
Plain films are helpful to rule out other etiologies, such as neoplasm and infection.
Therapy is conservative. Use of a knee immobilizer for a few days may improve compliance, especially in more severe cases. Pads or braces also can be used for support. Once the acute symptoms have abated, quadricep-stretching exercises, including hip extension for a complete stretch of the extensor mechanism, should be performed to reduce tension on the tibial tubercle. Stretching exercises for the hamstrings, which are commonly tight, also should be performed.