Knee Ligament Injuries PDF

OBGECTIVES • Knee ligament injuries • Meniscal tears • Tibial plateau fractures • Fractures tibia and fibula • Rupture Achilles tendon ‫ عبد اللطيف الزيدي‬.‫د‬ LIGAMENTOUS INJURIES OF THE KNEE Acute knee ligament injuries : common in sports &RTA. Knee stability depends on joint capsule, intra -&...

OBGECTIVES • Knee ligament injuries • Meniscal tears • Tibial plateau fractures • Fractures tibia and fibula • Rupture Achilles tendon ‫ عبد اللطيف الزيدي‬.‫د‬ LIGAMENTOUS INJURIES OF THE KNEE Acute knee ligament injuries : common in sports &RTA. Knee stability depends on joint capsule, intra -& extra –articular ligaments &muscles rather than on bony structures. MOI: Valgus force→ MCL tear; Valgus +rotation→ MCL+ ACL tear; Valgus +rotation +weight bearing→ MCL+ACL+ medial meniscus tear; Varus force→ LCL tear; Varus + rotation→ LCL + ACL tear; Dashboard injury→ PCL tear. CLINICAL PICTURE • history of twisting injury→ immediate painful doughy swelling (hemarthrosis) while in meniscus injury the swelling is late & fluctuant (synovial effusion). Look for site of maximum tenderness, bruises &abrasion. Valgus stress test Varus stress test • Test for ligament tear : Partial tear is painful with no abnormal movement, if in doubt→ stress view . Complete tear → painless abnormal movement . • If the knee open with valgus or varus stress in 30°flexion→ only collateral tear; If open in extension→ capsule + collateral + cruciate tear ; Anteroposterior stability: posterior sag→ PCL tear; anterior drawer test→ ACL; Lachman test→ ACL. • ACL injuries are common and acutely present with large hemarthrosis and pain; the Lachman test (anterior drawer at 20 degrees of flexion) is the most valid test for diagnosing ACL tears Aspiration of hemarthrosis and injection of lidocaine may assist in diagnosis painfully swollen knee injuries. Hemarthrosis ANTERIOR DRAWER TEST. With the knee in 90 flexion, the foot is anchored by the examiner sitting on it then, using both hands, the upper end of the tibia is grasped firmly and rocked backwards and forwards to see if there is any anteroposterior glide Posterior sag sign: - place the patient supine, hip at 45 degree, and knee at 90 degree - view the knee from the lateral position - posterior translation of the tibia in relation to the femur, indicates a PCL injury Imaging: X -ray: may show avulsion fracture e.g. ACL may avulse tibial spine. MRI: to differentiate partial from complete tear. Arthroscopy: is not indicated in acute complete tear. Treatment: Partial tear : aspirate hemarthrosis→ 6weeks functional brace or crepe bandage with early exercise. Complete tear : MCL or LCL tear: 6weeks cast -brace→ exercise. ACL or PCL tear : 6weeks cast -brace→ exercise; later if instability persists→ ligament reconstruction. Combined collateral + ACL or PCL : 6weeks cast -brace → exercise→ later reconstruction. Avulsion injuries should be surgically treated earlier rather than later MENISCAL TEARS STRUCTURE OF THE MENISCUS • Medial is semicircular • The medial meniscus is less mobile than the lateral and, consequently, more liable to tearing when subjected to abnormal stresses. • Lateral almost a complete circle Moves ~1 cm through full ROM • Both made of fibrocartilage Vascular supply good in the most peripheral 20% of the fibers Supplied by the geniculate arteries • Inner 1/3 of the ring is avascular • Relatively thin • Nourished through synovial fluid • Middle 1/3 of the ring is combination FUNCTION OF THE MENISCI • Distribute load across the knee joint • 2-4x body weight during walking • 6-8x body weight during running • Menisci deepen the socket of the tibial plateau, contributing to stability • Wedge shape limits translation of femur on tibial plateau TEARS AND ZONES PATHOPHYSIOLOGY • In acute knee injuries with ACL intact, medial meniscal injury is 5 times more likely than lateral • In acute knee injuries with ACL ruptured, lateral meniscus more likely to be involved TYPES OF MENISCAL TEAR Grinding forces split the fibers of the meniscus If the separated fragment remains attached at the front and back, the lesion is called a bucket-handle tear. If the tear emerges at the free edge of the meniscus, it leaves a tongue based anteriorly (an anterior horn tear) or posteriorly (a posterior horn tear). HISTORY: THE KEY TO DIAGNOSIS • Twisting on planted foot • Waxing and waning course with pain and effusion intermittently in chronic injury • Locking or popping of knee, especially if followed by effusion IS THERE EFFUSION? Check if there is effusion by Ballottement test MCMURRAY’S TEST APLEY’S TEST VALUE OF MRI AS DIAGNOSTIC TOOL • Studies do NOT prove it superior to composite clinical exam • Many false positives appear TREATMENT OPTIONS Conservative • Not an option if knee locked, fragment not reduced • Symptom relief with NSAIDS, immobilization • Physical therapy focusing on closed chain exercise of quadriceps and hamstrings • Operative • Total meniscectomy • Partial meniscectomy • Meniscal repair Best done by Arthroscopy CRITERIA FOR MENISCAL REPAIR VS. PARTIAL MENISCECTOMY Criterion Distance from rim Repair <3mm Ptl. Meniscectomy >3mm Mobility of fragment Stable Mobile Age of injury Recent Old Ret. To Play Later Sooner Age of patient Younger Older TIBIAL PLATEAU FRACTURES • Typical mechanism of axial compression with varus/valgus loading • Lateral plateau fractures most common, followed by bicondylar, followed by medial plateau fractures • • Bimodal distribution • – High-energy trauma: adult and middle-aged patients, more common in males – Low-energy falls: osteoporotic insufficiency fractures, more common in women • Lateral plateau fractures: lateral meniscal pathology • • Medial plateau fractures: medial meniscal pathology CLASSIFICATION • Schatzker classification – Type I: lateral split – Type II: lateral split depression – Type III: lateral depression – Type IV: medial plateau, possible knee dislocation equivalent – Type V: bicondylar – Type VI: metaphyseal-diaphyseal dissociation Clinical features The patient is nearly always an adult. The joint is swollen and has the doughy feel of a haemarthrosis. There is diffuse tenderness on the side of the fracture, and also on the opposite side if a ligament is injured. TREATMENT Conservative: aspirate the haemarthrosis & apply crepe bandage→ 10days continuous passive motion(CPM) machine 3weeks hinged cast -brace→ 4weeks Partial Weight Bearing(PWB)→ Full Weight Bearing(FWB). • Operative ORIF using lag screws or buttress plate + • elevation of any depression &support with bone graft. Type І&ІV: if undisplaced → conservative If displaced → ORIF . Type П&Ш: If depression >5mm &young→ ORIF. if <5mm or elderly→ conservative. Type V &VІ: if severe, there is a risk of compartment syndrome. If undisplaced or slightly displaced in elderly→ conservative. If displaced→ ORIF or circular -frame external fixation or 6weeks skeletal traction→ 6weeks PWB. COMPLICATIONS Early :Compartment syndrome – Maintain a high index of suspicion of compartment syndrome. – Most common in the anterior and lateral compartments. – Increased risk with higher-energy injuries and more proximal fractures. Late: joint stiffness, varus or valgus deformity & OA ( after 5-10yrs ). Fractures of proximal end of fibula: MOI: either direct or indirect twisting injury. The isolated # is rare &needs no treatment but look for associated injuries: 1-ankle # or ligament tear (Maisonneuve #); always x -ray the ankle . 2-knee collateral ligament injury. 3-peroneal nerve injury. late complication : peroneal nerve entrapment. Fractures of the tibia &fibula: is a common injury & many times it is open because of it's subcutaneous position. MOI: twisting force→ spiral # at different level s. Angulation force→ transverse or oblique # at the same level. Direct injury may crush or split the overlying skin → compound # Classification by Gustillow Aim of treatment: 1-limit soft tissue damage &preserve the skin; 2-prevent compartment syndrome; 3-reduce &hold the #; 4-start early weight bearing; 5-early joint movement. Conservative: full length cast(from upper thigh to metatarsal necks) &elevation for 2weeks→ checking x -ray &change the cast as swelling↓→ 8-12weeks PWB. If skin viability is doubtful→ 2weeks skeletal traction then casting. Indications: 1-undisplaced &slightly displaced #; & 2 -displaced # that can be reduced(&remain stable) by manipulat ion. Operative: indications: 1 -failure of closed reduction; & 2 -displaced high energy # that are comminuted &unstable. Types of fixations : closed intramedullary nailing with locking screws (for closed diaphyseal # , plate fixation (for metaphyseal #) & external fixation (for open# -&closed comminuted #). Complications: Early: 1-vascular injury: proximal 1/3 # may injure the popliteal artery→ repair. 2-compartment syndrome(proximal #)→ fasciotomy→ external fixation. 3-infection: the incidence is 1% for G І &30% f or G ШC. Late: 1-malunion : 1.5cm shortening &7˚angulation are acceptable, if more or mal rotation→ tibial osteotomy. 2-delayed union & nonunion : especially in high energy #, infection or bone loss → stable fixation &bone graft. 3-joint stiffness: of ankle may lasts 12 months. ACHILLES TENDON RUPTURE Rupture probably occurs only if the tendon is degenerate. Consequently most patients are over 40 years old. While pushing off (running or jumping), the calf muscle contracts; but the contraction is resisted by body weight and the tendon ruptures. The patient feels as if he or she has been struck just above the heel, and is unable rise up on tiptoes. CLINICAL PICTURE a gap can be seen and felt about 5 cm above the insertion of the tendon. Plantarflexion of the foot is weak and is not accompanied by tautening of the tendon. Simmonds’ test is helpful: with the patient prone, the calf is squeezed; if the tendon is intact the foot is seen to plantarflex involuntarily; if the tendon is ruptured the foot remains still. Positive Simmonds’ test TREATMENT If the patient is seen early, the ends of the tendon may approximate when the foot is passively plantarflexed. If so, a plaster cast is applied with the foot in equinus and is worn for 8 weeks; thereafter, a shoe with a raised heel is worn for a further 6 weeks. Operative repair is probably more reliable, but immobilization in equinus for 8 weeks and a heel raise for a further 6 weeks are still needed. THE END