Hamstring tendon graft for anterior cruciate ligament reconstruction - Home Study Program

AORN Journal,  Oct, 2002  by Deborah M. Boni,  George E. Herriott

• E-mail
• Print
• Link

INITIAL PATIENT ASSESSMENT

When the patient presents for evaluation, he or she usually complains of knee instability. The patient most often describes having heard a pop or having felt a tearing sensation inside the knee. Moderate to severe pain was felt at the time of injury, and the patient was unable to continue the causative activity because of the pain. The knee joint became swollen within 24 hours of injury, but many patients state that the swelling occurred within three hours. Some patients report that the knee seemed to recover but became unstable and now feels as though it is giving out, especially during activities that require lateral movement of the knee, such as cutting or pivoting. Many patients, however, deny knee pain with straight ahead activities, such as running or jogging. Symptoms may be vague in nature and often require more definitive testing. Clinical evaluation includes the Lachman test, anterior drawer test, and pivot-shift maneuver. The ACL may be imaged, if necessary, by obtaining a magnetic resonance imaging (MRI) scan.

In the Lachman test, the patient lies supine on the table with the involved leg beside the health care provider performing the examination. The examiner holds the patient's knee at 30 degrees of flexion (Figure 2). The examiner stabilizes the patient's femur with one hand while anteriorly translating the proximal aspect of the tibia with the other hand. "A positive sign is indicated by a mushy, soft, end-feel when the tibia is moved forward." (3) A positive sign also may indicate that other structures, including the anterior capsule, are injured. (4) The Lachman test is the most sensitive test for detecting ACL deficiency.

[FIGURE 2 OMITTED]

For the anterior drawer test, the patient lies supine on the examination table with his or her knees flexed 90 degrees and both feet flat on the table (Figure 3). The health care provider examining the patient cups his or her hands around the patient's knee, placing his or her fingers on the medial and lateral hamstring insertion points and thumbs on the medial and lateral joint lines. The examiner then draws the tibia forward. The ACL may be torn if the tibia slides forward from under the femur (ie, positive anterior draw sign). (5)

[FIGURE 3 OMITTED]

The last definitive test for an ACL tear is the pivot-shift maneuver. The patient lies supine with his or her hip flexed 20 degrees and relaxed in slight medial rotation. The examiner holds the patient's foot with one hand, using the other hand to flex the patient's knee slightly. The examiner flexes the patient's knee by placing the heel of the hand behind the patient's fibula, over the lateral head of the gastrocnemius muscle, and medially rotating the patient's tibia, which causes the tibia to sublux anteriorly.

An MRI usually is obtained if two out of three of the previously mentioned tests are positive for an ACL tear. An MRI also may be performed to evaluate for additional or associated injuries. Reconstructive surgery is considered depending on how active the patient currently is and plans to be in the future, whether there are associated injuries, and the amount of abnormal knee laxity demonstrated.