Sinding-Larsen-Johansson Syndrome

What is Sinding-Larsen-Johansson syndrome?

Sinding-Larsen-Johansson — often abbreviated to SLJ — is a growth-related condition affecting the bottom tip of the kneecap, where the patellar tendon attaches. It's similar in nature to Osgood-Schlatter but happens at the kneecap end of the same tendon rather than at the shin end.

It's typically seen in active children aged 10 to 13, often those who do a lot of running and jumping. The repeated pulling forces during a growth phase irritate the still-developing attachment point.

Like Osgood-Schlatter, it's a benign and self-limiting condition that settles as growth completes — but it can be a frustrating problem in the meantime if it's interfering with sport.

What does it feel like?

The pain is at the bottom tip of the kneecap. Common features include:

• Pain at the lower edge of the kneecap, particularly with activity

• Tenderness when pressing on the spot

• Pain on jumping, running or kneeling

• Stiffness after rest

• A small lump or swelling in some cases

Symptoms tend to be activity-related and can vary considerably from week to week depending on how active the child has been.

How is it diagnosed?

Diagnosis is usually clinical — the typical age, location of pain and pattern of symptoms make the picture clear.

Imaging isn't routinely required. X-rays may show characteristic changes at the lower pole of the kneecap and are sometimes useful to confirm the diagnosis or exclude other causes.

The assessment also considers what else might be contributing — particularly if symptoms aren't following the expected pattern.

What are the treatment options?

Like Osgood-Schlatter, SLJ is managed with activity modification, simple pain relief and physiotherapy. The aim is to let the natural process complete while keeping the child active where comfortable.

Surgery is essentially never needed for SLJ. The condition resolves with growth in the great majority of cases. Nev will work through the right plan for your child's situation at your consultation.

When should you get it checked?

Seek a specialist assessment if:

• Your child has persistent pain at the bottom of the kneecap

• Pain is interfering with sport or activity

• Self-management hasn't produced improvement

• You'd like the diagnosis confirmed and a clear plan

• You're worried about whether continued sport is wise

SLJ is a recognisable, manageable condition. Most children get back to full sport with the right plan and some patience.