Microsurgical Dissection Of The Posterior Cruciate Ligament

Charalampos A Makris MD, Anastasios D Georgoulis MD,
Christos D Papageorgiou MD, Ulf G Moebius MD, Panayotis N Soucacos MD
Department of Orthopaedic Surgery
University of Ioannina, Medical School
(Chairman: Professor PN Soucacos)
45110 Ioannina, GREECE 

Author responsible for correspondence (First Author) :
Charalampos A Makris, MD
Orthopaedic Surgeon
Department of Orthopaedic Surgery
University of Ioannina, Medical School
Telephone:+30-651-74612, +30-651-97515
Fax:+30-651-74770, +30-651-46222 

Abstract 

In twenty-four cadaveric knees, we measured the main dimensions of the Posterior Cruciate Ligament (PCL) and its femoral and tibial attachment sites. We dissected the ligament using magnifying loupes and an operative microscope in order to verify the exact fiber anatomy, always careful to avoid creating artificially separated bundles. Different fiber-regions of the PCL were, afterwards, substituted with patellar tendon-bone graft. The behavior of the graft during joint motion was recorded. 

The PCL consists of four fiber-regions, partially separate from the anatomic point of view, but functionally distinct. These fiber-regions are the anterior, central, posterior-longitudinal and posterior-oblique, named for their orientation and the osseous sites of their insertion. 

The anterior and central fiber-regions are the bulk of the ligament, while the remaining 15% of the ligament consists of the posterior fiber-regions. During joint motion, changes in the length of these fiber-regions were observed. The anterior fiber-region appears to be the most non-isometric and acts as a primary restraint to posterior tibial translation mainly between 30o and 90o flexion. The posterior fiber-regions (especially the posterior-oblique) appear to be the most isometric and act as primary restraints in extension and partially in deep flexion, respectively. The central fiber-region appears to have an intermediate behavior as regards length changes and acts as a primary restraint to posterior tibial translation between 30o and 120oflexion. Additionally, it appears to be the widest of the fiber-regions. Similar to the aforementioned behaviors were observed, when the patellar tendon-bone graft substituted the anterior, posterior and central fiber-regions, respectively. 

Based on these observations, one can conclude that selective isometric reconstruction of the posterior fiber-regions does not appear ideal since it would leave the bulk of the ligament largely unreconstructed. Contrarily, anatomic reconstruction using a large graft, following the central fiber-region orientation and attachment sites, could yield good results even for patients requiring stability in deep flexion. 

Key words 

Posterior Cruciate Ligament, Functional anatomy, Fiber-regions, Microsurgical dissection, Anatomic reconstruction. 


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