Introduction
Define/describe the condition
The Posterior Cruciate Ligament (PCL) is the primary restraint to posterior tibial translation and is made of two anatomically distinct bundles: the anterolateral (AL) bundle and the posteromedial (PM) bundle. PCL injuries are rare in comparison to Anterior Cruciate Ligament (ACL) injuries, with incidence reports of 3 to 44% of acute knee injuries. 40% of these injuries have been reported to occur in isolation (Clancy WG Jr, Sutherland TB 1994), with most of these injuries due to traffic accidents and competitive sport participation.
Anatomy
Describe the pertinent anatomy and provide links to relevant pages
The AL bundle, which comprises 95% of the ligament, is taut in 90 degree flexion and is lax in extension, whereas the PM bundle is taut at full extension and somewhat lax in flexion. These two bundles originate from the posterosuperior aspect of the femoral attachment, pass obliquely, and then insert onto the posterolateral surface of the tibia (Makris CA et al., 2000).
Pathogenesis
Describe the biologic basis of the disorder or the mechanism of injury
Natural History
Describe the natural history,epidemiology and prognosis
Patient History and Physical Findings
Describe the means to elicit the most useful information from the patient history and physical examination as well as the relevant findings
There are several clinical tests used to detect and grade PCL lesions. The most commonly used grading system is based on a scale of I-III using the posterior drawer test. In a normal knee, the medial tibial plateau is approximately 1cm anterior to the medial femoral condyle at 90 degree flexion of the knee. A grade I injury will display up to 0.5cm less step off than the uninjured knee, but remains anterior to the medial femoral condyle. A grade II injury is classified as a 0.5-1cm less step off, with the medial tibial plateau and the medial femoral condyle being flush. Finally, when the medial tibial plateau is displaced posterior to the medial femoral condyle, this constitutes as a grade III (Grassmayer MJ et al., 2007). A grade III is highly correlated with combined injuries (Shelbourne KD et al., 1994).
Imaging and other Diagnostic Studies
Describe appropriate radiologic and other diagnostic studies
Differential Diagnosis
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Treatment
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Medical therapy
Nonoperative treatment
Operative treatment - include links to pages with detailed surgical techniques
Reconstruction of the PCL is recommended in an effort to prevent progressive osteoarthritis and functional disability (Dandy, DJ 1982). There are a variety of different graft tissues used, including autografts, allografts, and synthetic ligaments. Currently, Bone-patellar tendon-bone and hamstring tendon autografts are the most commonly used grafts. Recent studies have reported favorable outcomes with the LARS artificial ligament (Ligament Advanced Reinforcement System, Surgical Implants and Devices, Arc-sur-Tille, France). Compared with the 4SHG, Li et al.found that the knee laxity and function examination results were superior in the LARS group (Li et al., 2008). Previous generations of artificial ligaments have been criticized for their high device failure rate and reactive synovitis (Sledge SL et al. 1992, Gillquist J, Odensten M 1993). Li et al. found no signs of ligament rupture or clinically evident synovitis in the studied patients who underwent PCL reconstruction with the LARS artificial ligament.
Indications and contraindications
Pearls and Pitfalls
Tips and problems to avoid
Postoperative Care
Include immediate postoperative care and rehabilitation
Outcome
Include functional and prosthetic survivorship data as applicable
Complications
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Selected References
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