ACL, PCL and meniscal tear Flashcards
Clinical features of ACL tear
- Twisting knee while weight bearing
- Without contact
- Unable to weight bear
- Rapid joint swelling
- Significant pain
- Laxity in Lachman/Anterior drawer test
What causes rapid joint swelling in ACL tear?
- Highly vascular ligament
- –> haemoarthrosis
- Clinically apparent within 15-30mins
Lachman test
More sensitive than ADT
Differentials for ACL tear presentation
- Tibial plateau #
- Distal femoral #
- Meniscal tear
- Collateral ligament injury
- Quadriceps tendon injury
Imaging for ACL tear
- AP and lateral X-rays
- MRI scan of knee - GOLD STANDARD - confirm and pick up any meniscal tears additonally
half of ACL tears have meniscal tear too
Fracture that suggests ACL tear
- Segond fracture
- Bony avulsion of lateral proximal tibia
Immediate management ACL tear
- RICE - rest, ice, compression, elevation
- Can apply cricket pad knee splint for comfort
two options for ACL management
- Dependent on current levels of activity and suitability for surgery
- Conservative vs surgical reconstruction
Conservative management ACL
- Rehabilitation
- Strength training quadriceps to stabilise knee
- Use cricket pad knee splint for comfort - rarely need admissio
Surgical management ACL
- Surgical reconstruction - following a period of pre-rehabilitation, physio prior to surgery, autograft or allograft
- Acute surgical repair - depends on location of tear in ligament - GA knee arthroscopy, resuture ends together
Auto - from self, allo - from someone else
Why is timing of swelling important in knee injuries?
- Haemoarthrosis vs post traumatic effusion
- Rapid = haemoarthrosis often associated with ruptured cruciate or # bone within joint capsule
- Slower = reactive synovitis - meniscal or chondral pathology
PCL injury mechanism
- High energy trauma
- Eg direct blow to proximal tibia during RTA
- OR can be low energy when hyperflexed knee and plantarflexed foot
Clinical features PCL tear
- Immediate posterior knee pain
- Instability of joint - +ve posterior drawer test
Imaging PCL
- MRI - gold standard
Management PCL tear
- Conservative
- Knee brace and physio
- If continues to be symptomatic and recurrent instability may require surgery with insertion of graft
If associated with other injuries then specialist knee surgery needed
Function menisci
- Shock absorbers
- Increased articulating SA
Medial vs lateral menisci
- Medial is less circular than lateral
- Attached to medial collateral ligament
- Lateral collateral is NOT attached to lateral menisci
Cause of meniscal tears
- Trauma or degenerative disease
- Trauma = twisted knee while flexed and weight bearing
Types of meniscal tear
- Longitudinal - most common, aka ‘Bucket Handle’
- Vertical
- Transverse - parrot beak
- Degenerative
Patient symptoms of mensical tear
- Tearing sensation
- Intense, sudden onset pain
- Swells SLOWLY - 6-12 hrs
Signs of meniscal tear on examination
- Tenderness along joint line
- Joint effusion
- Limited knee flexion
Specific tests for meniscal tears
- McMurrays test
- Apleys Grind test
Investigations for meniscal tear
- X-ray - exclude #
- MRI = gold standard for soft tissue
Management menisci injuries - small <1cm
- Rest and elevation
- Tear will heal and pain subside over next few days
Larger tears/remaining symptomatic menisci tears
- Arthroscopic surgery
- If tear in outer 1/3 - repair with sutures as rich vascular supply
- If inner 1/3rd - trim tear to reduce locking
- Middle third may be repaired or trimmed
Complications post ligament/menisci injury
- Secondary osteoarthirtis
- Knee arthroscopy -damage to local structures eg saphenous nerve and vein, peroneal nerve and popliteal vessels, also DVT
