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What is Sinding Larsen-Johansson (SLJ) Syndrome?

Sinding-Larsen-Johansson syndrome (SLJ) is characterized by inflammation of the kneecap (patella). It is an overuse, “traction” injury that affects the lowest growth plate on the patella, located at the inferior pole. Sinding Larsen Johnannson syndrome is often termed “Jumper’s Knee” but is medically referred to as inferior pole osteochondrosis. SLJ mostly happens to athletes between the ages of 10 and 15—a common time for growth spurts. SLJ is more common in adolescents who play sports that require a lot of running or jumping because these activities increase the stresses on the knee joint, especially the kneecap.


  • This syndrome, similar to Osgood-Schlatter disease, is caused by repetitive stress and traction of the patellar tendon where it originates on the bottom of the kneecap (inferior pole)
  • Weak or tight thigh musculature (quadriceps muscle group)
  • Improper training techniques

Signs and Symptoms

  • Localized pain over lower portion of the kneecap
  • Pain with running, jumping, kneeling, squatting, stairs
  • Pain after sitting for a prolonged period of time with the knees flexed
  • Occasionally some swelling over inferior pole is seen


SLJS is generally treated conservatively and includes:

  • Rest
  • Avoidance or modification of activities that provoke symptoms (i.e., running or jumping)
  • Limiting activities to remain pain free
  • Stretching and strengthening program of the quadriceps and hamstring groups (thigh musculature)
  • Utilization of a patellar tendon strap (“chopat”) strap
  • Additional pain management can include over the counter anti-inflammatories and ice following activity
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