History
- Young to middle age
- Twisting injury
- Kneeling/squatting injury
- Joint line pain
- Difficutly walking
- True locking
Signs
- Limp
- Effusion
- Possible painful block to extension

Joint line tenderness
image copyright NHS Lothian.

Unable to kneel, squat or Duck waddle
image copyright NHS Lothian.

User dependent specific test as part of assessment eg McMurrays Test
image copyright NHS Lothian.
Secondary care referral
- Immediate if truly locked, patient unable to flex or extend knee
- Routine if primary care treatment exhausted
Primary care investigations
- None indicated
Primary care treatment
- Analgesia
- PRICE (Protection, Rest, Ice, Compression, Elevation)
- Physiotherapy