Osgood-Schlatter disease is a benign knee condition involving pain, swelling and inflammation at the tibial tuberosity.
The disease is one of the commonest causes of knee pain in adolescents, particularly if they are athletic. Boys are more often affected, typically aged 13-14. Girls are usually younger, about 10-11.
The cause of the condition is thought to be micro-trauma at the insertion of the patellar tendon on to the tibia. There is high tension where the powerful quadriceps attaches to a relatively small area, and rapid growth in adolescence combined with vigorous activity adds to the strain.
A minor bone flake may be avulsed. Eventually, secondary bone formation occurs in the tendon near its insertion, producing a visible swelling.
Pain is the commonest presenting symptom. It may be bilateral and is aggravated during and after exercise.
A direct blow on the tuberosity produces excessive pain. In some cases there is a history of precipitating trauma.
On examination, quadriceps wasting may be observed, but the knee joint itself is normal.
The tibial tuberosity is prominent and tender, with pain aggravated by resisted knee extension. There may be a bursa at the insertion site, and the resulting fluctuant mass adds to the prominence.
The condition is most often diagnosed from symptoms and examination.
X-rays can show changes but are not usually performed unless other aetiologies are suspected.
Care should be taken to make sure the patient does not have an acute fracture, tumour, osteomyelitis or infection.
Other causes of pain
Other causes of knee pain to consider include anterior knee pain syndrome, quadriceps tendon avulsion, bursitis, patellofemoral stress syndrome, patellar tendinitis and Sinding-Larsen's disease. These cause pain more proximally, where the patellar tendon is attached to the patella.
Osgood-Schlatter disease responds well to rest and analgesia. Acute symptoms usually show improvement over two to four months. It may be advisable to avoid the precipitating activity for six months. After this, a gradual return to normal sporting activities is advised, with quadriceps exercises and hamstring stretching. If pain recurs, more rest is advised.
For the minority of patients with persistent symptoms, treatments such as knee splints or casts have been tried, but they may be no better than waiting.
Surgical treatment is rarely indicated and is usually reserved for recurrent disabling pain. Options include bone fragment removal or a tuberosity-thinning procedure.
Most symptoms resolve within a year but there may be mild discomfort for two to three years. The tuberosity prominence usually persists into adult life, but causes few problems.
- Dr Lackey is a GP in Killingworth, Tyne and Wear, and Mr Sutton is a consultant orthopaedic surgeon in Northumberland
- Osgood-Schlatter disease is a benign, self-limiting teenage knee condition.
- Pain is located where the patellar tendon attaches to the tibial tuberosity.
- The condition responds well to rest and analgesia.
- Activities can be gradually reintroduced after time, but should be stopped again if symptoms recur.