Overuse injuries in young athletes increase proportionately to training demands. Osgood-Schlatter Disease (OSD) is a common overuse injury characterized as traction apophysitis of the tibial tuberosity.
The tibial tuberosity is an apophysis that serves as the attachment site for the patellar tendon. In the developing athlete, this apophysis is a biomechanically weak point, which is predisposed to injury during periods of rapid skeletal development. When training demands exceed the ability of the muscle-tendon unit to accommodate these stresses, this increased tension results in bony microtrauma and inflammation of the apophysis.
OSD is more common in athletes, particularly those who participate in soccer, gymnastics, basketball, running or track. It is most common between the ages of 10-15. It has relatively equal prevalence between boys and girls. OSD is more common in athletes who have experienced apophysitis at another anatomical location, or whose siblings suffered from the same disease.
Traction apophysitis is not unique to the tibial tuberosity. Sever’s disease is traction apophysitis of the posterior calcaneus and is considered one of the most common overuse injuries in adolescent athletes. Sinding-Larsen-Johansson disease develops from increased tension on the patellar tendon at the inferior pole of the patella. Iselin’s disease is a traction apophysitis of the tuberosity of the fifth metatarsal. The hip and pelvis have several apophyses, including the ASIS and AIIS, which are frequently injured in runners. The iliac crest apophysis is sometimes irritated in runners whose arms create excessive trunk rotation. The ischial tuberosity apophysis may be irritated from running, jumping, kicking or other activities that forcefully activate the hamstrings and adductors. The greater and lesser trochanteric apophyses may be injured during forceful kicking movements.
OSD patients often present with a non-traumatic history of progressively increasing pain directly over the tibial tuberosity. Symptoms are generally exacerbated by exercise. Upon examination, the tibial tuberosity may be swollen and inflamed. In persistent cases, the tuberosity may be more prominent on the involved side. Range of motion may be diminished, and full passive knee flexion is often uncomfortable. Pain typically intensifies when contracting the quadriceps against resistance.
The diagnosis of OSD is generally based on a classic history and physical presentation. Radiographs are not always necessary unless avulsion fracture or bony pathology is suspected. OSD may become evident following minor trauma but clinicians should be suspicious if the athlete hears a “pop” followed by immediate onset of acute pain and ecchymosis, as this is more typical of an avulsion fracture. The differential diagnosis of OSD includes patellofemoral pain syndrome, patellar tendinopathy, Sinding-Larsen-Johansson Disease, plica and bony pathology, including infection or tumor.
The diagnosis of OSD is very straight forward, but a more challenging task is to identify the biomechanical factors that produced this disorder. Inflexibility or weakness of the hamstring, quadriceps or calves will generate excessive loads during athletic activity. Other conditions that apply abnormal biomechanical forces through the knee extensor mechanism and predispose athletes to OSD include patella Alta, patellar tracking disorders, tibial torsion, foot pronation, and pes planus. Athletes who run with a very narrow stride (on a line) may increase their risk of OSD. An analysis of running and jumping mechanics may assist the clinician in developing a rehabilitation protocol to decrease forces passing through the tibial tuberosity and allow them to be better distributed throughout the entire lower extremity.
The first step in developing a treatment strategy is to determine the severity of the condition and an appropriate period of rest. Some athletes with mild cases may continue activity as long as it does not produce significantly greater pain. Other athletes may require extended periods of rest to properly manage the condition. Most athletes will benefit from some type of cross-training while selectively resting the quadriceps. These activities may include swimming, weight lifting, stationary cycling, and upper body exercise.
Common treatments include icing, NSAIDS, stretching and strengthening. Rehabilitation activities should not cause an increase in pain. Initially, exercises should focus on stretching the hamstring, gastroc, soleus, iliotibial band, and hip adductors. As the pain subsides, strengthening the hamstrings, hip rotators, calves, and finally, quadriceps will prove beneficial. Return to the functional activity begins with jogging and moves into sprinting, cutting, squatting and finally, jumping. Use of a patellar tendon strap likely a Cho-Pat? a brace may provide benefit, although few studies have been done to determine its true efficacy for this condition.
Chiropractors should not see OSD as “a kid with knee pain who needs to rest”, but rather as an opportunity to identify and correct underlying biomechanical and or training problems that would otherwise most certainly resurface as new problems in the future.