Orthopaedic Knee Conditions Flashcards
Meniscal tear causes
- Acute
- Twisting especially in deep flexion
- Degenerative
- Osteoarthritis
- Medial meniscal tears more common
- More fixed structure
- Unlikely to heal
- Poor blood supply
Meniscal Tear Presentation
- Tearing sensation in knee
- Intense sudden onset pain
- Swells slowly over following 6-12 hours
- If Meniscal tear results in a free body within the knee it may be locked in flexion
Meniscal tear examination
- Look
- Significant joint effusion
- Feel
- Joint line tenderness
- Move
- Limited knee flexion
- Special tests
- McMurray’s test, Apley’s Grind test
What are the main functions of the menisci?
- Shock absorbers of the knee
- Increase articulating surface area
Differentials for an acutely swollen knee joint following trauma
- Fracture
- Meniscal tear
- Cruciate ligament tear
- Collateral ligament tear
- Osteochondritis dissicans
Meniscal tear investigations
- X-Ray - to exclude a fracture
- MRI - gold standard
Meniscal tear non-operative treatment
- Rest, ice, compression and elevation
Most small meniscal tears (<1cm) will initially swell however the pain will subside over the next few days as the tear heals
Meniscal tear operative treatment
- Arthroscopic surgery for larger tears or those remaining symptomatic
- Outer third of meniscus has a rich vascular supply = repair
- Inner third of meniscus = resection
ACL position
It runs from between tibial eminences to lateral wall of intercondylar notch of femur
ACL blood supply
middle geniculate artery
ACL function
- Important stabiliser of knee joint
- Primary restraint to limit anterior translation of the tibia (relative to femur)
- Contributes to knee rotational stability
ACL tear cause and female:male ratio
- History of twisting the knee while weight bearing
- Occurs without contact
- Females:male 4.5:1
ACL tear presentation
- Rapid joint swelling
- haemarthrosis
- Usually unable to weight bear
- Significant pain
ACL tear examination
- Look
- effusion (if recent injury)
- Special tests
- Lachman test
- Anterior draw test
ACL tear investigations
- X-ray
- Segond fracture (bony avulsion of the lateral proximal tibia) is pathognomic of ACL injury
- MRI
- Gold standard to confirm diagnosis of ACL injury
- Pick up an associated meniscal tears
- Lateral – simultaneous with acl tear (48%)
- Medial – secondary to shear from chronic instability
- Pick up MCL tears
ACL tear non-operative treatment
- Initial management: rest, ice, compression, elevation
- Conservative management
- Strength training of quadriceps to stabilise the knee
Complications of ACL tear
Post-traumatic osteoarthritis is a well established complication of both ACL injury and ACL reconstructive surgery
Superficial and deep MCL function
- superficial - primary restraint to valgus stress
- deep - contributes to full knee extension
MCL tear pathology and associated injuries
- severe valgus stress
- usually contact related
- associated injuries
- ACL tear
- Meniscal tear
MCL tear symptoms
- May report hearing a ‘pop’
- Immediate medial joint line pain
- Swelling follows after a few hours
MCL tear examination
- Feel
- tender medial joint line
- tender femoral insertion of MCL
- Move
- Increased laxity with testing MCL via the valgus stress test
MCL tear investigations
- X-Ray
- To exclude any fractures
- MRI
- Gold standard
- Assess location and severity of injury
MCL tear non-operative treatment
- Majority
- RICE, NSAIDs
- Physiotherapy
- Depending on grade of injury: knee brace +/- crutches
