Arthrometric Aspects of Anterior Cruciate Ligament Surgery Before and After Reconstruction With Patellar Tendon Grafts

Instrumented arthrometry is an important treatment adjunct for anterior cruciate ligament (ACL)-deficient patients before and after patellar tendon reconstruction, which provides objectivity to other subjective outcome measures and allows for accurate comparison between studies. Increasing numbers of clinical reports are using arthrometry to objectively report anterior displacements. Arthrometry measurements allow the worldwide orthopaedic community to accurately compare and evaluate reported subjective results. It should be noted that patient satisfaction and subjective evaluations by the examiner and patient may overestimate the presumed ligamentous stability, and in these cases, the KT arthrometer provides important objectivity. This objective data may be the only means of early detection of laxity after ACL reconstruction. In this article, a review of the available data regarding arthrometry before and after patellar tendon ACL reconstruction is presented as well as a rationale for selecting a maximum manual side-to-side difference of 3 mm or an absolute laxity of 10 mm as the diagnostic criteria for ACL deficiency. Knee laxity testing data should be incorporated into the objective preoperative and postoperative evaluation of the ACL-deficient patient, and the goal of reconstruction should be to match the contralateral normal knee. Arthrometry data are important to the researcher for objective evaluation and comparison of populations and to clinicians for objective outcomes in individual patients after patellar tendon ACL reconstruction.