Sinding-Larsen Johansson disease is one of the osteochondroses. It can be a cause of anterior knee pain. It is usually seen in a boy in his pre-teens. Pain is usually related to activity and is typically over the inferior pole of the patella. There is a separate article giving an overview of the Osteochondroses.

Pathophysiology

Osteochondroses all involve a defect in ossification. The mechanism in Sinding-Larsen Johansson disease is thought to be persistent traction at the cartilaginous junction of the patella and the patellar ligament/tendon (tendon and ligament are interchangeable terms here), usually at the inferior patellar pole.¹ It is essentially a chronic stress injury with overuse of the patella-patellar tendon junction.² Similar symptoms can sometimes occur proximally, at the junction of the quadriceps tendon and the patella.³

Presentation

• Activity-related anterior knee pain.
• On examination there is inferior patella tenderness.

Differential diagnosis¹

• Patella avulsion fractures.
• Patella stress fracture.
• Bipartite patella (type I).
• Osgood-Schlatter disease.
• Jumper's knee is considered in older adolescents; Sinding-Larsen Johansson disease is the adolescent equivalent of jumper's knee²

Investigations

• Knee X-ray: can show calcification or ossification at the junction between the patella and the patella ligament.
• MRI scan can be used.^4,5

Management

• Physiotherapy is the mainstay of treatment, including quadriceps strengthening exercises.
• Surgery is not usually needed.

Prognosis

• As the skeleton matures, symptoms usually improve and, in this way, it is regarded as a self-limiting process. However, symptoms may be present for at least a year.
• A case report has presented a case of a pathological patellar fracture through the site of an old Sinding-Larsen Johansson lesion.⁶

Document references

1. Sinding-Larsen-Johanssen disease, Wheeless' Textbook of Orthopaedics
2. Sullivan AJ; Osgood-Schlatter Disease, eMedicine, Mar 2009
3. Tyler W, McCarthy EF; Osteochondrosis of the superior pole of the patella: two cases with histologic correlation. Iowa Orthop J. 2002;22:86-9. [abstract]
4. Lamoureux C; Patella Fracture Imaging, eMedicine, Sep 2010
5. Peace KA, Lee JC, Healy J; Imaging the infrapatellar tendon in the elite athlete. Clin Radiol. 2006 Jul;61(7):570-8. [abstract]
6. Freedman DM, Kono M, Johnson EE; Pathologic patellar fracture at the site of an old Sinding-Larsen-Johansson lesion: a case report of a 33-year-old male. J Orthop Trauma. 2005 Sep;19(8):582-5. [abstract]

Acknowledgements