Meniscal injury — Rapid | Doctor’s Passport

Synopsis

Distinguish acute repairable meniscal injury and a genuinely locked knee from common degenerative tears, use radiographs and MRI selectively, begin rehabilitation early, and reserve arthroscopy for a defined mechanical target.

Clarify mechanism, timing of swelling, joint-line pain, catching and whether the knee is truly fixed or merely painful to extend.
Examine effusion, range, joint lines, McMurray or Thessaly only when tolerated, ligament stability, patella, hip and distal neurovascular status; no single manoeuvre is definitive.
Obtain plain radiographs after trauma or when osteoarthritis is plausible. MRI is the preferred soft-tissue study when a repairable acute tear or locked knee will change management.
A true locked knee receives urgent specialist assessment and should not be sent through a routine months-long rehabilitation pathway before the mechanical block is addressed.
Most non-locked degenerative tears begin with education, progressive strength and activity rehabilitation and osteoarthritis care where applicable.
Surgery should target a defined lesion after clinical and imaging correlation, with meniscal preservation and repair preferred over unnecessary resection when feasible.
Arthroscopic lavage or debridement is not treatment for uncomplicated osteoarthritis, and an incidental MRI tear is not itself an indication.
After repair, follow the surgeon's pattern-specific loading and range protocol; restore swelling control, extension, quadriceps strength and neuromuscular function before return to pivoting activity.

Key red flags

A fixed inability to extend rather than pain-limited movement after a twist suggests a displaced tear and requires urgent specialist review.

Large immediate haemarthrosis, gross instability or high-energy injury suggests cruciate rupture, osteochondral fracture or knee dislocation and broadens imaging and vascular assessment.

Fever, erythema and severe passive pain indicates possible septic arthritis and requires aspiration before any steroid or routine rehabilitation.

Inability to bear weight with focal bony tenderness after trauma requires fracture imaging before attributing symptoms to a meniscus.

Investigation priorities

First-line history and examinationFirst stepFirst line

Separate fixed locking, traumatic target and degenerative pain.

Management branches

LockedUrgent mechanical pathway

The knee has a persistent fixed extension block after a plausible injury.

Protect the knee, document range, effusion, ligament and neurovascular findings and obtain trauma radiographs.
Refer urgently to a soft-tissue knee clinician and arrange expedited MRI if it does not delay definitive care.
Treat a displaced repairable lesion arthroscopically with meniscal preservation where feasible.
Use pattern-specific postoperative range, loading and strength rehabilitation.

Key medicines

Short-course NSAID when suitableUse one licensed oral NSAID at the lowest effective adult dose for the shortest period needed to support movement and rehabilitation, or a licensed topical NSAID when local treatment is sufficient.Assess gastrointestinal, renal, liver and cardiovascular disease, blood pressure, pregnancy, anticoagulants and concurrent NSAIDs; avoid masking worsening locking, infection or fracture and stop when no functional benefit remains.

Paracetamol for brief rescueIf suitable, use paracetamol 500–1,000 mg orally up to every 4–6 hours as needed, maximum 4 g in 24 hours for a healthy adult, with a lower maximum in low body weight, frailty, liver disease, malnutrition or hazardous alcohol use.Check all combination products to avoid overdose and do not allow analgesia to postpone assessment of a locked, hot or traumatically non-weight-bearing knee.

Open full textbook →Answer 2 questions