Dr. Pomeranz's Ultimate Guide to :

MRI of the Knee

Sinding-Larsen-Johansson syndrome

Sinding Larsen Johansson Syndrome (SLJ) is a condition affecting adolescents. Osteochondrosis disturbs the extensor mechanism of the knee in a way that the patellar tendon attachment to the inferior pole of the patella is irregular.1




Sinding-Larsen-Johansson Syndrome: Differential Diagnosis

    • Injury to the infrapatellar fat pad or fat pad impingement syndrome
    • Hoffa disease
    • Patellofemoral joint dysfunction or maltracking
    • Mucoid degeneration of the infrapatellar tendon3
    • Patellar sleeve injury
    • Infrapatellar plica syndrome




Sinding-Larson-Johansson Syndrome: Pearls

SLJ could lead to tendonitis and calcification in the ligament, causing an increased rupture rate, slower recovery time, and more complications post-surgery.2




Sinding-Larsen-Johansson Syndrome: Treatment

  • Refrain from activities that exacerbate symptoms, apply ice, use a supportive brace, and keep elevated when possible.
  • Anti-inflammatories can assist with reduction of swelling.
  • Physical therapy can assist in strengthening and stretching the muscles.




Sinding-Larsen-Johansson Syndrome: References

  1. Medlar, R. C., et al., ‘Sinding-Larsen-Johansson Disease. Its Etiology and Natural History’, Journal of Bone & Joint Surgery, December 1978, vol. 60, no. 8, p. 1113-1116.
  2. Francesco Olivia, ‘Physiopathology of intratendinous calcific deposition’, BMC Medicine, 2012.
  3. Klucinec, B., ‘Recalcitrant Infrapatellar Tendinitis and Surgical Outcome in a Collegiate Basketball Player: A Case Report’, Journal of Athletic Training, June 2001, vol. 36, no. 2, p. 174-181.



Sinding-Larsen-Johansson syndrome: Example

This 10-year-old male presents with knee pain. What’s the diagnosis? What is indicated by the arrows in the back of the knee? Is it concerning?
image12  image33
  Image 1 - PDW_SPAIR_Sagittal                           Image 2 - T1W_aTSE_Coronal
The diagnosis is Sinding-Larsen-Johansson syndrome or inferior patellar “apophysitis” (image 1, blue arrow). The green arrows indicate lymph nodes, and they are innocuous (since they contain fat in the coronal, image 2). It is common to see lymph nodes behind the femur, particularly in children. Of course they are more numerous or larger in patients with inflammatory processes of the knee such as JIA (juvenile idiopathic arthritis).