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Child Orthopedics
Spine - Cervical
Spine - Lumbar
Spine - Thoracic

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Why is it so important that the doctor found a positive pivot-shift test during arthroscopic surgery that wasn't there when I was awake? That was the justification for doing a ligament reconstruction surgery when I thought I was just having it scoped, repaired, and on to rehab.

They explain why it's so difficult for surgeons to tell if the ligament is intact (okay) or not. Sometimes, a partially torn ligament looks perfectly fine. But it's really damaged and over time, it starts to lengthen or stretch out. Ligaments don't really stretch and bounce back like a rubber band. They are more likely to stretch and stay stretched out. And without a strong connection to hold the bones together, the knee joint can become unstable and give way underneath you. Sometimes a partially torn ACL can be treated conservatively with nonoperative methods such as antiinflammatories and an exercise or rehab program. The surgeon's task is to determine which patients can be treated this way and who needs surgery to repair or reconstruct the ligament. Making the right decision is important because ligaments don't have much of a blood supply. That means self-repair of a partial tear is not possible. Under the right conditions, it will eventually tear completely. Avoiding such an injury is often the goal, especially with athletes who are trying to stay in the game despite a partial tear. How does the surgeon accurately diagnose the problem? That can be a problem in itself. When clinical tests commonly used by examiners are positive (e.g., Lachman test, pivot-shift test), then it's clear that there is an ACL tear. But studies show that these hands-on tests can appear normal when up to 75 per cent of the ligament is torn. Surgeons are advised to perform the pivot-shift test under anesthesia when the ligament appears to be torn. In this way, the effects of muscle spasm and guarding are eliminated and the results are more accurate. This test is performed with the patient lying supine (on his or her back) with the hip passively flexed or bent to 30 degrees. The examiner stands beside the patient. The lower leg and ankle are grasped keeping the lower leg internally rotated about 20 degrees. The knee is allowed to sag into full extension. Force is applied to the outside of the knee while it is slowly straightened. If the tibia (lower leg bone) clunks into place as the knee is extended, there is likely a tear of the ACL. Studies show that the pivot-shift test is only 24 per cent sensitive when the patient is awake compared to 92 per cent sensitive when under anesthesia. Results of the pivot-shift test while in the operating room can be misleading if there is other soft tissue damage inside the joint. The surgeon must take the opportunity to double-check for problems such as cartilage, bone, or meniscal fragments in the joint. If the pivot-shift test is truly negative, the ligament is not functionally deficient. In other words, even though the ligament is partially torn, it can still function to some extent. Those are the patients who can do well with a rehab program instead of surgery. A nonoperative course of treatment is especially indicated if the individual isn't very active and/or doesn't have much in the way of symptoms.


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