What is Sinding–Larsen–Johansson Syndrome?
Sinding–Larsen–Johansson syndrome (SLJ) is an overuse injury at the growth plate at the bottom of the kneecap, where the patellar tendon attaches.
What happens in SLJ?
Repetitive stress from jumping and running irritates the growth plate at the lower pole of the patella, causing pain and swelling.
Common causes
- Rapid growth spurts
- High-impact jumping sports
- Tight quadriceps
- Overuse during training
Who is most affected
- Children aged 10–14
- Common in basketball, netball, and football players
- Often seen in boys but also in active girls
Symptoms
- Pain at the bottom of the kneecap
- Swelling and tenderness at the lower pole of the patella
- Pain is worse with jumping or squatting
If your child has pain at the kneecap during sport, book an assessment at Spinal and Sports Care.
Diagnosis
Clinical examination for tenderness at the patella:
- Pain with resisted quadriceps contraction
Imaging:
- X-rays are rarely needed unless to rule out other pathologies
Treatment options
Non-surgical:
- Activity modification
- Stretching of quads
- Ice and anti-inflammatory care
- Physiotherapy for strength and flexibility
Surgical:
- Very rare, usually resolves with growth
Role of physiotherapy
- Stretching and strengthening program
- Correct biomechanics
- Load management education
- Safe return-to-sport guidance
Recovery timeline
- 4–12 months, depending on severity and growth stage
Prevention
- Gradual training progressions
- Maintain quad flexibility
- Monitor training loads in young athletes
Taping and bracing
- Patellar tendon straps can reduce symptoms
- Knee sleeves may assist in comfort
When to see a physiotherapist or chiropractor
If knee pain persists for more than 2 weeks and limits sports, book at Spinal and Sports Care.
