Michael M. Reinold, Casey C. Carter and Kevin E. Wilk
Christopher D. Harner, Tracy M. Vogrin and Savio L-Y. Woo
This article discusses the anatomy and biomechanics of the posterior cruciate ligament (PCL) and PCL reconstructions and their implications for clinical management of PCL injuries. The PCL consists of two functional components, the anterolateral and posteromedial, based on their reciprocal tensioning patterns. The anterolateral has been the focus of single-bundle PCL reconstructions. Recent biomechanical studies have indicated that the posteromedial bundle also plays an important role, and double-bundle PCL reconstructions have also been proposed. The PCL works closely with the posterolateral structures in providing posterior knee stability. The effects of several surgical variables, including graft fixation, associated injuries, and tunnel placement, that can significantly affect the outcome of PCL reconstruction are discussed. With improved knowledge of the PCL, new reconstructive techniques are being developed, offering the potential of more closely replicating the anatomy and biomechanics of the normal PCL and improving clinical outcomes of PCL injuries.
Marc R. Safran, Christopher D. Harner, Jorge L. Giraldo, Scott M. Lephart, Paul A. Borsa and Freddie H. Fu
Proprioceptive deficits have been demonstrated following anterior cruciate ligament (ACL) disruption, but little research exists evaluating proprioception in the posterior cruciate ligament (PCL)-deficient and/or -reconstructed knee. We have studied proprioception in PCL-deficient and PCL-reconstructed knees. The following summarizes our protocol and results of proprioceptive testing of kinesthesia and joint position sense in participants with isolated PCL injuries and those who underwent PCL reconstruction. We studied 18 participants with isolated raptures of the PCL and 10 participants who underwent PCL reconstruction. Proprioception was evaluated by two tests: the threshold to detect passive motion (TTDPM) and the ability to passively reproduce passive positioning (RPP). These assess kinesthesia and joint position sense, respectively. We have shown that isolated PCL deficiency in the human knee does result in reduced kinesthesia and enhanced joint position sense. Thus, the proprioceptive mechanoreceptors in the PCL do appear to have some function. We further found that PCL reconstruction significantly improved kinesthesia at 45° of knee flexion, while 110° was not significantly different between the involved and uninvolved knee in both studies.
Matthew D. Pepe and Christopher D. Harner
Michael J. Axe, Kirk H. Swigart and Lynn Snyder-Mackler
Kevin E. Wilk, James R. Andrews, William G. Clancy Jr., Heber C. Crockett and James W. O'Mara Jr.
Treatment of posterior cruciate ligament (PCL) injuries has changed considerably in recent years. This article discusses current rehabilitation for PCL disruptions in athletes. The treatment of PCL injuries varies somewhat based on the chronicity (acute vs. chronic) of injury and associated pathologies. The authors provide their treatment algorithm for the acute and chronic PCL-injured-knee patient. Nonoperative rehabilitation is discussed with a focus on immediate motion, quadriceps muscle strengthening, and functional rehabilitation. A discussion of the biomechanics of exercise is provided, with a focus on tibiofemoral shear forces and PCL strains. Surgical treatment is also discussed, with the current surgical approach being either the two-tunnel or the one-tunnel patellar tendon autograft procedure. The rehabilitation program after surgery is based on the healing constraints, surgical technique, biomechanics of the PCL during functional activities, and exercise. With the new changes in surgical technique and in the rehabilitation process, the authors believe that the outcome after PCL reconstruction will be enhanced.