Ligaments of the Knee 2
- Medial collateral Ligament (MCL): Medial femoral condyle to posterior medial tibial crest - shares interconnections with joint capsule, muscle/tendon units and medial meniscus
Provides resistance against lateral to medial valgus stress
Most commonly injured |
- Lateral Collateral ligament (LCL) - Lateral epicondyle of the femur to distal fibular head
resists medial to lateral varus movements during frist 30 degree of knee flexion + limits ext rot when the knee is flexed |
Classification
- Grade I: Stretch with no macroscopic fibre disruption |
- Grade II: Partial fibre disruption |
- Grade III: Rupture |
Grade III can involve the ACL as well |
- MCL, ACL, meniscus - unhappy triad |
Presentation
- Pain on medial/lateral aspect of the knee after trauma |
- May hear pop with pain |
- Loss of ROM from pain and swelling |
- Aggravated by activity |
- Weakness/instable knee |
- Clicking can be present if meniscus is affected |
- Tenderness/swelling over affected ligament |
- Baker's cyst could indicate intra-articular damage |
- PROM flex and ext usually preserved unless pain/swelling/isolated |
- +ve Valgus/varus stress test |
- +ve bulge sign |
- +ve Anterior draw, +ve Lachman's +ve Pivot shift +ve lever test, +ve Posterior drawer, +ve Thessaly, +ve Mcmurray (for involvement of ACL, PCL and meniscus) |
Imaging
- Only if Ottowa knee rules present |
- MRI only if pre-op planning/investigating other areas affected |
DDx
- Meniscus injury |
- F# |
- Osteochondral lesion |
- Dislocation |
- Contusion |
- Patella subluxation |
- Tendinitis |
- Bursitis |
Management
- Grade II and Grade III need support (double upright hinged knee for II and immobiliser for III for 1-6 weeks) |
- Crutches can be used |
- RICE |
- ROM (flexion and ext to non-painful arc) |
Completed Phase I rehab when full weight bearing and normal gait |
Phase II: Quads, hamstrings, gastrosoleus, hip abductors strengthening
Closed chain kinetic - heel slides, short arc extensions, hamstring curls, toe raises, hip abduction, squats, wall slides, stationary bicycle, water aerobics) |
Progress when full ROM with no swelling |
Phase III: Straight line running - jogging and progressing to sprinting, then narrow S- shaped patterns, then sports specific drills |
- Continue with myofascial release and stretching : Hip flexors, Quads, Hamstrings, Gastrocnemius/soleus |
Pt return Grade I-II return to play within 1-3 weeks
Grade III needs >6 weeks to heal |
- Surgery only if functionally unstable or patients with persistent pain and/disability, failed conservative management |
Meniscus Injury
- Affixed to superior articular surface of tibia
- Peripheral 1/3 is vascularised and innervated - pain and proprioception
- Remainder is avascular and lacks nerve supply
- Transmits most of the compressive loads (mostly lateral, but medial = more stability), shock absorption, prevention of synovial impingement, synovial fluid distribution and lubrication
Demographics/Risk factors
- Males affected more than females |
- Can occur at any age, in elderly, degenerative tears can occur |
- Medial affected more than lateral (due to the mobility of lateral) |
Classification
- Traumatic or Degenerative |
- Vertical (commonest) - flap, parrot beak, bucket handle |
- Oblique |
- Radial/Transverse - disrupt fibres - more common in lateral meniscus |
- Longitudinal |
- Horizontal |
- Complex |
Presentation
- Young patients = traumatic (sudden twist on a loaded knee) |
- Older patients = insidious |
- Patient may have difficulty weight bearing - altered gait |
- Intermittent movement-related pain - deep knee bends |
- Clicking, catching and locking - 20-45 degrees of extension is common |
- Patient reports a sense of giving way/buckling |
- Joint line tenderness |
- Palpation of the joint = increased synovial fluid production (cysts) |
- Palpation of mensci
Lateral: flexion and external rot
Medial: Knee flexion and internal rot of tibia |
- ROM limited in flex and ext (rubbery movement block if bucket handle) |
- +ve Thessaly test, +ve Mcmurrays |
Imaging
- May be needed to rule out F# |
- Ottawa knee rules
Age >55
Tenderness at the head of the fibula
Isolated tenderness of the patella
Inability to flex the knee >90 degrees
Inability to weight bear both immediately and in ER for 4 steps |
- MRI but false positives are common (only if surgery is indicated) |
Management
- Peripheral radial tears <5mm and longitudinal tears along posterior horn of the lateral meniscus are shown to improve with con care |
- RICE |
- Avoid twisting on the knee |
- Bracing |
- Temp stop the sports |
- Stretching and release of hamstrings, adductors, quads, gastrosoleus, popliteus |
- EMT/SMT of ankle , fibular head,hip, SI , spine |
- Stationary bicycling, water walking, |
- Isometric strength - as swelling decreases |
- Then dynamic exercises - single leg calf raises, knee flex, ext, lunges >80 degrees of knee flex |
- Hip/knee stability - gluteal weakness and patellofemoral tracking |
- Arch supports if hyperpronation |
- Rehab after surgery usually advised (hamstrings and quads, ROM exercises |
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