Doctors use several tests to measure knee instability after an anterior cruciate ligament (ACL) tear. A special machine can measure the amount of knee laxity. Two other tests are often used: the Lachman test and the pivot-shift test. These same tests are used after an operation to repair the torn ligament. It helps doctors see how stable the knee is after surgery.
How do patients’ symptoms compare to these findings? If the knee is stable, does the patient still have pain and swelling? If the knee isn’t stable, will patients know it by how limited they are in function?
The purpose of this study was to see if there’s any link between objective test results and patient’s reported symptoms. Any connection between these two has never been reported. Two hundred patients having an ACL reconstruction were studied. All patients were followed at least two years.
Two sets of data were collected: the doctor’s report and the patient’s report. Patients informed their doctors about the following symptoms:
Patients were also asked about satisfaction with the results; their ability to walk, squat, or run; and their ability to enjoy sports or other activities. Climbing stairs and daily activity or work level were also measured.
The authors report no link between two of the tests and symptoms reported. Only the pivot-shift test was related to patient satisfaction and knee function. A positive pivot-shift test was accompanied by symptoms where the knee seemed to give way. The same patients also had trouble with twisting and cutting motions in sports activities. These findings support the use of the pivot-shift exam to test function after ACL reconstruction.