Knee Examination History: ask about current mechanism of injury, prior injuries or surgeries to knee. Inspect: pt. should be examined while walking, note gait, muscular development, functional ROM. – Inspect the knee for swelling, ecchymosis, effusion, masses, patella location, erythema, signs of local trauma, note leg lengths, active range of motion.
Knee Examination Check for neurovascular status Palpate the knee, patella, medial and lateral joint lines Place the knee in various stress testing
Knee X-Rays Ottawa Knee rules: determines the need for x-rays, proven sensitive for fracture. – Age > 55 – Tenderness head of fibula – Isolated patellar tenderness – Inability to flex knee 90 degrees – Inability to bear weight
Patella Fractures Result from direct blow such as knee hitting dashboard in MVA, fall on flexed knee, forceful contraction of quad. Muscle. Transverse fractures most common PE: focal patellar tenderness, swelling, effusion. – Check for extensor mechanism by doing straight leg raising against gravity.
Patella Fracture Tx: non-displaced patella fracture w/intact extensor mechanism is treated w/knee immobilizer, rest, ice, elevation, NSAIDS/Opioids, then long leg cast for 6 weeks. – Fractures that are displaced > 3 mm or assoc. w/disruption of extensor mechanism requires Ortho. Referral for open reduction & internal fixation
Femoral Condyle Fractures These injuries secondary to direct trauma from fall w/axial loading or blow to distal femur. Exam reveals pain, swelling, deformity, rotation, shortening and inability to ambulate Potential for popliteal artery injury, check for ipsilateral hip dislocations or fractures
Femoral Condyle Fractures Cast immobilization for stable, non- displaced fractures Open reduction internal fixation for displaced fractures or any degree of joint incongruity Complications: DVT, fat embolus, delay or malunion, development of OA
Tibial Spine & Tuberosity Fractures Tibial spine Fx’s: – Anterior tibial spine more commonly fractured – Painful swollen knee, inability to extend fully and + Lachman’s sign – If fracture is incomplete or non- displaced, it should be immobilized in full extension w/knee immobilizer & Ortho outpt. follow-up. – Complete, displaced fractures require open reduction internal fixation (ORIF)
Tibial Spine & Tuberosity Tibial tuberosity: quadriceps mechanism inserts on tibial tubercle – Sudden force to flexed knee w/quadriceps contraction may avulse tibial tubercle – If avulsion is small or non- displaced just immobilize. – If displaced, needs ORIF
Tibial Plateau Fractures Produced by varus or valgus forces combined w/axial loading which drives femoral condyles into tibial plateau – Examples: fall from a height or leg struck by car – Painful swelling of knee, limited ROM, ligamentous instability
Tibial Plateau Fractures If one plateau is fractured but non- displaced, Tx w/knee immobilizer, non-weight bearing, outpt. Ortho follow-up for long leg cast Complications: popliteal artery injury, DVT, OA
Ligamentous & Meniscal Injuries Functional instability of the knee is determined by stress testing which can demonstrate abnormal laxity. Medial collateral ligament: valgus or abduction applied to knee to stress test Lateral collateral ligament: varus or adduction applied to knee to stress test If there is laxity >1cm w/out firm endpoint then there is complete rupture of MCL/LCL If there is laxity < 1cm w/a firm endpoint then there is a partial tear If there is no ligamentous instability but pain w/stress testing, then there is ligament strain
Anterior Cruciate Ligament Mechanism is usually a deceleration, hyperextension or internal rotation of tibia on femur May hear “pop”, swelling, assoc. w/medial meniscal tear Dx: Lachman’s test, anterior drawer sign, pivot shift – Displacement of > 6 mm is considered positive for tear.
Posterior Cruciate Ligament Less common than ACL injury Mechanism is anterior or posterior force applied to tibia or lower leg DX: Posterior drawer test
Knee Ligaments Dx: X-rays may be normal or only reveal an effusion MRI has approximately 90% accuracy in detecting ligamentous or meniscal injuries
Knee Ligaments Tx: Stable injuries involving only one ligament w/minor strain can be treated w/knee immobilizer, ice packs, elevation, NSAIDS, ambulation that is comfortable for the pt. If knee is immobilized, have pt. do daily ROM activities to avoid contractures and maintain mobility. Professional athletes(Kellen Winslow Jr.) w/single ligament rupture or pts. w/more than one ligament ruptured, need Ortho evaluation for surgical repair.
Meniscal Injuries Mechanism is usually cutting, squatting or twisting maneuvers. Ask pt. if there is locking of the knee on flexion or extension that is painful or limits there activity. Exam: joint line tenderness or Positive McMurray’s test(+50% only) Tx: partial weight bearing, NSAIDS, referral to Ortho as outpt.
Knee Dislocation: Result of ligamentous disruption, posterior dislocation is most common With posterior dislocation, ACL & PCL injuries/disruption are common Assoc injuries include popliteal artery injury, peroneal nerve injury, ligamentous and meniscal injuries True Ortho Emergency!
Knee Dislocation Early reduction using longitudinal traction is essential. Neurovascular status is important to check pre&post-reduction Ortho C/S & hospitalization required. If signs of popliteal artery injury: absent pulses, bruits, distal ischemia, C/S Vascular surgeon for possible arteriography.
Patella Dislocation Mechanism is a twisting motion on an extended knee. – Patella is usually laterally displaced over lateral condyle – May have tearing of medial joint capsule – Reduction involves conscious sedation, flexing the hip, hyperextending the knee, and slide patella back into place
Patella Dislocation Check X-ray to r/o fracture Tx: knee immobilizer, partial weight bearing, NSAIDS, isometric quad. strengthening exercises and outpt. F/U to Ortho.
Quadriceps/Patellar Tendon Rupture Mechanism is forceful contraction of quadriceps muscle or falling on a flexed knee. Significant pain, swelling and inability to extend a fully flexed knee against minimal resistance. May see a high riding patella on lateral x-ray view of knee Tx: surgical repair by Ortho
Osteochondritis Dissecans Disorder in which a segment of articular cartilage and subchondral bone become separated from underlying bone Results from acute or chronic trauma Pts. c/o pain, swelling, cannot recall specific injury Dx: x-rays Tx: protective weight bearing if epiphysis still open.
Osteonecrosis Bony infarction caused by disruption of blood flow Can be primary or secondary – Primary: etiology unknown – Secondary: steroids, SLE, ETOHism, sickle cell, renal transplant
Osteonecrosis Pts. Are typically elderly women who present w/acute knee pain X-rays are usually normal early on, MRI is diagnostic Tx: protective weight bearing, NSAIDS. – Advanced disease options include: arthroscopic debridement, curretage,drilling of lesion, bone grafting, tibial osteomy, osteochondral allografts, total knee arthroplasty
Patellar Tendonitis AKA “Jumpers Knee” b/c seen in runners, basketball players, volleyball players and high jumpers Pain is in patellar tendon, worse when going from sitting to standing position and running up hills Tx: Heat, NSAIDS, quadriceps muscle strengthening
Chondromalacia Patellae Overuse syndrome of patellar cartilage Caused by patello-femoral malalignment which leads to tracking abnormality of patella putting excessive lateral pressure on articular cartilage Seen in young active women, pain worse w/stair climbing and rising from a chair
Chondromalacia Patellae Patellar compression test: push the patella distal in trochlear groove w/knee extended and quadriceps muscle contracted, this will elicit pain. Tx: rest, NSAIDS, quadriceps strength exercises.
Penetrating Knee Injury/Joint Foreign Body If knee joint has been penetrated, immediate Ortho C/S for joint irrigation in OR. Radiopague F.B.(metal, glass) will be seen on X-ray F.B. in knee joint need to be removed. Tx: IV antibiotics to cover Staph/Strep. For penetrating wounds or foreign bodies Don’t forget Td prophylaxis!
Fibula Fractures Most fibula fractures are result of tibia fractures. Treatment is determined by injury to tibia Fibula only bears 15% of body weight so pts. may ambulate. Isolated fibula fracture treated w/either knee immobilization or elastic wrap.
Tibia Fractures Mechanism usually involve torsional force, bending force or direct blow. Closed, minimally displaced fractures can be treated w/reduction and immobilization If fracture is displaced, ortho. C/S for further reduction Watch for compartment syndrome Open fracture: immediate Ortho C/S, immobilize fracture, sterile coverage of the wound, Td update, IV antibiotics(1 st gen. Ceph.), to OR for irrigation & debridement.
Achilles Tendon Rupture Mechanism is forceful plantar flexion. Pt. may hear popping sound, difficulty ambulating Risk factors: quinolone use, RA, SLE, steroid use Dx: palpable gap in tendon, + Thompson test, inability to walk on toes Tx: splint in neutral position, refer to Ortho and don’t forget the crutches.
Shin Splints Refers to pain over medial or anterior tibia that occurs w/exertion & relieved w/rest Caused by micro tears of muscular fibers at the point of bony attachment Tenderness on exam over anterior tibia X-rays may reveal stress fracture, bone scan is most sensitive Tx: stop offending activity, orthotics, strength and flexibilty exercises
Osgood Schlatter Disease Seen in athletic teenagers Lesion is partial separation of tibial tuberosity at insertion of patellar tendon Palpation of tibial tuberosity reveals tenderness & induration X-ray lateral may reveal elevation of tibial tubercle off of tibia Tx: stop offending activities, cold compresses, NSAIDS, Ortho referral
Questions: 1. T or F: An ACL tear is commonly assoc. w/medial meniscal tear as well. 2. T or F: When you prescribe a knee immobilizer, you must instruct pt. to do daily ROM exercises. 3. T or F: Posterior knee dislocation is assoc. w/possible popliteal artery injury. 4. T or F: For open fractures, Tx includes, Td prophylaxis. Sterile dressing, IV ATBX, irrigation and debridement in OR. 5. T or F: RA, SLE, steroid injections, quinolone ATBX are all risk factors for achilles tendon rupture. Answers : ALL T!