Reviewed on : 1 Dec 2014

Reviewed by : Pete Thompson, Consultant Orthopaedic Surgeon, UHCW

Expires : 1 Dec 2016

Differentials of knee instability:

Ligament injury (most commonly anterior cruciate ligament)

• Clear history of significant twisting injury
• Laxity apparent on examination, e.g. Lachman Test, Anterior Drawer, Pivot Shift or Collateral Ligament Stress Tests

Meniscus injury

• Either following twisting injury or from chronic degenerative tear
• May present with locking or ‘giving way’
• Localised joint line pain and tenderness

Patella instability

• Clear history of patella dislocation (usually lateral)
• Patella apprehension and J-tracking

Pain and muscle weakness

• Common symptom in patients with knee pain from arthritis. Described as collapsing or ‘giving way’

Other, e.g. loose body

• May present with locking or ‘giving way’

GP management and self-management

• Moderate analgesia (paracetamol, topical NSAID, oral NSAID as appropriate)
• Strengthening exercises (with referral to Coventry MSK physio services as appropriate)
• Activity modification
• Specific knee brace, e.g. for recurrent patella instability (available from MSK physio, UHCW appliance department or purchase online)

Referral to acute knee clinic if below criteria satisfied

1. Acute injury  with instability (within last six weeks)
2. Significant injury, likely to require surgical intervention/use of a brace

• Suspected ligament injury from history or examination
• Suspected meniscal tear with locking (inability to fully extend)
• First time traumatic patella dislocation (reference 1)

The Acute Knee Clinic is held every Thursday morning at UHCW. Contact the orthopaedic secretaries by phone or fax, marking your letter “urgent – acute knee clinic”. Alternatively, you can phone the consultant on duty in Fracture Clinic, open seven days a week. Please note this service is not for degenerative knee conditions.

Referral to routine elective knee clinic if below criteria satisfied

1. Chronic instability impacting on patient’s functional ability, refractory to GP and self-management as outlined above

• Suspected meniscal injury – symptoms interfere with the ability to work or persist despite 6–8 weeks of rehabilitation by a physiotherapist (reference 1)
• Suspected medial or lateral collateral ligament injury – symptoms interfere with the ability to work or persist despite 4–6 weeks of rehabilitation by a physiotherapist (reference 1)
• Suspected ACL injury impacting functional ability or intention to return to pivoting sports, e.g. football, rugby, netball, squash etc. (reference 2)
• Suspected PCL injury impacting functional ability
• Suspected meniscal injury impacting functional ability
• Recurrent patella dislocation (reference 3)
• Patient amenable to surgical intervention where relevant

Radiological investigations to be requested for use in clinic

1. Suspected ligament injury: MRI
2. Suspected meniscal injury: MRI
3. Patella instability: Xray (AP, lateral and skyline views), MRI
4. Other: Xray (AP, lateral and skyline views), MRI
5. Pain: See Knee Pain – Adults page on GP Gateway