Lateral ligament sprains are most common
Grading of ankle ligament injuries and their management
Grade | Definition | Clinical findings | Specific management |
1 | Ligament stretch with microscopic tearing | Local tenderness, minimal swelling, no joint instability | Elastic compression bandage (for 2 weeks) Heals in 2-4 weeks |
2 | Ligament stretch with partial tearing | Local tenderness, oedema, ecchymosis, partial loss of joint motion but definite end point | Stirrup splint (for 4 weeks) Heals in 4-12 weeks |
3 | Complete rupture of ligament | Marked swelling, severe pain, gross ankle instability | Aircast boot (for 6 weeks)May require surgical repair Heals in 3-6 months |
Structure damaged | Mechanism | Symptoms |
Cruciate ligaments | Anterior: forced flexion, hyperextension of knee (e.g. during tackle) or rotation injury to extended knee Posterior: tibia forced backwards, e.g. fall on object or against dashboard in road traffic accident May hear βpopβ | Knee collapses when put weight on it Immediate pain Difficulty weight-bearing Rapidly forming haemarthrosis |
Collateral ligaments | Medial: blow to lateral side of knee Lateral: blow to medial side of knee (check peroneal nerve) Lateral ligament injuries are uncommon | Pain on inner/outer knee Immediate pain Difficulty weight-bearing May have symptoms of instability (if high grade injury) |
Meniscus tears | Rotational injury to flexed knee | Immediate pain Difficulty weight-bearing Slowly forming effusion Clicking and locking (locking limiting extension) |
Grading of knee ligament injuries and their management
Grade | Definition | Clinical findings | Specific management |
1 | Ligament stretch with microscopic tearing | Knee stable on clinical testing | Elastic or wool & crepe bandage (for 2 weeks) Heals in 2-4 weeks |
2 | Ligament stretch with partial tearing | Laxity but definite end point | Knee brace (for 4 weeks, or until no laxity on examination) Heals in 4-12 weeks |
3 | Complete rupture of ligament | Joint opens >1cm | Medial/lateral collateral ligament: knee brace (for 6-12 weeks or until no laxity on examination) Anterior/posterior cruciate ligament: cast and surgical reconstruction |
Meniscus | Damage to menisci | Knee gives way, clicks and locks | Arthroscopic repair if locked knee or knee is no better in 2 weeks |
Which is the most commonly damaged knee ligament?
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Draw a diagram of the knee with valgus and varus deformities, and another to show how valgus/varus forces can be applied.
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What is the anatomical purpose of the menisci of the knee?
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