ACL

Anterior Cruciate Ligament (ACL) Injury definition:

 Anterior Cruciate Ligament (ACL) Injury Key Features

• An injury involving an audible pop when the knee buckles
• Acute swelling immediately (or within 4 hours)
• Instability occurs with lateral movement activities and going down stairs
 • ACL tears are common with sporting injuries
 • Can result from both contact (valgus blow to the knee) and non-contact (jumping, pivoting, and deceleration) activities Clinical Findings
 • Acute swelling of the knee, causing difficulty with motion
• After the swelling has resolved, the patient can walk with a ‘stiff-knee’ gait or quadriceps avoidance gait because of the instability
• Patients describe symptoms of instability while performing side-to-side maneuvers or descending stairs Diagnosis
• Stability tests assess the amount of laxity of the knee while performing side-to-side maneuvers or descending stairs
 • The Lachman test is performed with the patient lying supine and the knee flexed to 20–30 degrees (Table 41–10)
• The anterior drawer test is performed with the patient lying supine and the knee flexed to 90 degrees (Table 41–10)
 • The pivot shift test is performed with the patient lying supine with the knee in full extension and is used to determine amount of rotational laxity of knee (Table 41–10)
 • Plain radiographs are usually negative in ACL tears but are useful to rule out fractures
• MRI is the best method to diagnose ACL tears Treatment
• Most young and active patients will require surgical reconstruction of the ACL
 • Nonoperative treatments are usually reserved for older patients or those with a very sedentary lifestyle
 • Physical therapy can focus on hamstring strengthening and core stability
• An ACL brace can help stability Table 41–10. Knee examination. Maneuver Description Inspection Examine for the alignment of the lower extremities (varus, valgus, knee recurvatum), ankle eversion and foot pronation, gait, SEADS. Palpation Include important landmarks:

patellofemoral joint, medial and lateral joint lines (especially posterior aspects), pes anserine bursa, distal iliotibial band and Gerdy tubercle (iliotibial band insertion). Range of motion testing Check range of motion actively (patient performs) and passively (clinician performs), especially with flexion and extension of the knee normally 0–10 degrees of extension and 120–150 degrees of flexion. Knee strength testing Test resisted knee extension and knee flexion strength manually. Ligament stress tests Lachman test Performed with the patient lying supine, and the knee flexed to 20–30 degrees. The examiner grasps the distal femur from the lateral side, and the proximal tibia with the other hand on the medial side. With the knee in neutral position, stabilize the femur, and pull the tibia anteriorly using a similar force to lifting a 10–15 pound weight. Excessive anterior translation of the tibia compared with the other side indicates injury to the anterior cruciate ligament. Anterior drawer Performed with the patient lying supine and the knee flexed to 90 degrees. The clinician stabilizes the patient’s foot by sitting on it and grasps the proximal tibia with both hands around the calf and pulls anteriorly. A positive test finds anterior cruciate ligament laxity compared with the unaffected side. Pivot shift Used to determine the amount of rotational laxity of the knee. The patient is examined while lying supine with the knee in full extension. It is then slowly flexed while applying internal rotation and a valgus stress. The clinician feels for a subluxation at 20–40 degrees of knee flexion. The patient must remain very relaxed to have a positive test. Valgus stress Performed with the patient supine. The clinician should stand on the outside of the patient’s knee. With one hand, the clinician should hold the ankle while the other hand is supporting the leg at the level of the knee joint. A valgus stress is applied at the ankle to determine pain and laxity of the medial collateral ligament. The test should be performed at both 30 degrees and at 0 degrees of knee extension. Varus stress The patient is again placed supine. For the right knee, the clinician should be standing on the right side of the patient. The left hand of the examiner should be holding the ankle while the right hand is supporting the lateral thigh. A varus stress is applied at the ankle to determine pain and laxity of the lateral collateral ligament. The test should be performed at both 30 degrees and at 0 degrees of knee flexion. The sag sign The patient is placed supine and both hips and knees are flexed up to 90 degrees. Because of gravity, the posterior cruciate ligament-injured knee will have an obvious set-off at the anterior tibia that is “sagging” posteriorly. Posterior drawer The patient is placed supine with the knee flexed at 90 degrees (see Anterior drawer figure above). In a normal knee, the anterior tibia should be positioned about 10 mm anterior to the femoral condyle. The clinician can grasp the proximal tibia with both hands and push the tibia posteriorly. The movement, indicating laxity and possible tear of the posterior cruciate ligament, is compared with the uninjured knee. Meniscal signs McMurray test Performed with the patient lying supine. The clinician flexes the knee until the patient reports pain. For this test to be valid, it must be flexed pain-free beyond 90 degrees. The clinician externally rotates the patient’s foot and then extends the knee while palpating the medial knee for “click” in the medial compartment of the knee or pain reproducing pain from a meniscus injury. To test the lateral meniscus, the same maneuver is repeated while rotating the foot internally (53% sensitivity and 59–97% specificity). Modified McMurray Performed with the hip flexed to 90 degrees. The knee is then flexed maximally with internal or external rotation of the lower leg. The knee can then be rotated with the lower leg in internal or external rotation to capture the torn meniscus underneath the condyles. A positive test is pain over the joint line while the knee is being flexed and internally or externally rotated. Thessaly test Performed with the patient standing on one leg with knee slightly flexed. The patient is asked to twist the knee while standing on one leg. Pain can be elicited during twisting motion. Patellofemoral joint test Apprehension sign Suggests instability of the patellofemoral joint and is positive when the patient becomes apprehensive when the patella is deviated laterally. SEADS, swelling,

erythema, atrophy, deformity, and (surgical) scars. Papadakis MA, McPhee SJ, Rabow MW. eds. Current Medical Diagnosis & Treatment .Copyright jobbdsite.blogspot.com