Osgood-Schlatter disease is a self-limiting disorder of the knee, found during adolescence.

Pathogenesis

Osgood-Schlatter disease describes the condition in which small avulsion fractures within the tibial tuberosity are caused by traction of the patellar tendon on the tibial tuberosity during forceful contractions of the quadriceps muscles. The fractures occur within the ossification centre (apophysis). The condition tends to occur during the adolescent growth spurt before the tibial tuberosity has finished ossification. The strength of quadriceps, in children regularly practising sports that involve running and jumping, may exceed the ability of the tibial tuberosity to resist that force.¹ As the avulsed fragments heal and grow, the tibial tubercle may enlarge. The extent will depend on the severity and frequency of injury.

Epidemiology

• Knee pain is common in athletes. Both knees are affected in up to 30% of people with the condition.²
• It is more common in boys than in girls.
• It is seen in children who participate in sports such as football, basketball, gymnastics and volleyball.

Presentation

Symptoms

• Pain and swelling below the knee.
• Gradual onset.
• Relieved by rest and made worse by activity, particularly running or jumping.

Signs

• Examination reveals tenderness and swelling at the tibial tuberosity.
• Pain is provoked by knee extension against resistance or by hyperflexing the knee with the person lying prone.
• Hip examination is important because some childhood hip conditions (e.g. slipped capital femoral epiphysis) can refer pain to the knee.

Investigations

X-rays are only indicated if there is suspicion of other injuries. If taken they may reveal fragmentation and irregular ossification at the tibial tubercle.

Differential diagnosis of knee pain

Knee pain that is severe, persists at night or at rest, or is associated with bone pain at other sites should be investigated urgently or the child should be referred. A bone tumour should be suspected.

Knee pain associated with systemic symptoms

• Septic arthritis.
• Juvenile idiopathic arthritis.

Knee pain associated with an abnormal examination of the hip

• Perthes' disease.
• Slipped proximal femoral epiphysis.
• Transient synovitis.

Knee pain associated with injury

• Meniscal injuries.
• Collateral and cruciate ligament injuries.
• Stress fractures of the patella.
• Tibial tuberosity fracture.
• Prepatellar and infrapatellar bursitis.

Knee pain not associated with trauma or systemic symptoms

• Osteochondritis dissecans.
• Sinding-Larsen Johansson disease.
• Patellofemoral pain syndrome.

Management¹

General measures

• Most patients respond to conservative treatment consisting of rest from painful activities and application of ice.
• Advice about exercise should be tailored to the level of pain experienced by the patient, i.e. if they are able to continue with minimal discomfort, advise them to continue and return if they deteriorate. If symptoms are disturbing normal routine, a change may be needed in duration, frequency or intensity of exercise.
• If patients cannot tolerate a modified programme, a period of rest should be advised. Once symptoms have decreased to an acceptable level, advise introducing low-impact quadriceps exercises before gradually increasing the intensity of exercise. If symptoms recur, patients should stop exercises or reduce their intensity. Gradually re-establish exercise or increase exercise intensity on the basis of symptoms.
• Referral to a physiotherapist may be necessary to manage rehabilitation, particularly if recovery is slow.
• If pain persists into adulthood a referral to secondary care for assessment is recommended.

Pharmacological

• Simple analgesia such as paracetamol or ibuprofen, as needed, for pain.
• Corticosteroid injection is not recommended. Potential complications include subcutaneous atrophy.³

Surgical

• Surgery is rarely required.
• There may be an ossicle under the distal patellar tendon as a consequence of the disease.
• Surgical treatment gives good results in these unresolved cases.⁴ Arthroscopy has been used with good results.⁵

Prognosis

Osgood-Schlatter disease usually is self-limiting, but symptoms may continue for up to one year.² However, some complications can occur:

• Mild discomfort with kneeling.
• Residual bony deformity.
• Painful ossicles in the distal patellar tendon.⁶

Most patients are able to return to full activity within two to three weeks.

Document references

1. Osgood-Schlatter's disease, Prodigy (January 2010)
2. Gholve PA, Scher DM, Khakharia S, et al; Osgood Schlatter syndrome. Curr Opin Pediatr. 2007 Feb;19(1):44-50. [abstract]
3. Bloom OJ, Mackler L, Barbee J; Clinical inquiries. What is the best treatment for Osgood-Schlatter disease? J Fam Pract. 2004 Feb;53(2):153-6.
4. Pihlajamaki HK, Mattila VM, Parviainen M, et al; Long-term outcome after surgical treatment of unresolved Osgood-Schlatter disease J Bone Joint Surg Am. 2009 Oct;91(10):2350-8. [abstract]
5. DeBerardino TM, Branstetter JG, Owens BD; Arthroscopic treatment of unresolved Osgood-Schlatter lesions. Arthroscopy. 2007 Oct;23(10):1127.e1-3. Epub 2007 Mar 19. [abstract]
6. Cassas KJ, Cassettari-Wayhs A; Childhood and adolescent sports-related overuse injuries. Am Fam Physician. 2006 Mar 15;73(6):1014-22. [abstract]

Internet and further reading

• Chang AK, Osgood-Schlatter Disease in Emergency Medicine, Medscape, May 2010
• Sullivan AJ, Osgood-Schlatter Disease, Medscape, Mar 2009