Partial lesions of the posterior cruciate ligament of the knee: CT findings
Grasso, A.; Cellerini, M.
La Radiologia Medica 86(6): 802-807
1993
ISSN/ISBN: 0033-8362 PMID: 8295999 Document Number: 414430
Posterior cruciate ligament (PCL) tears are more common than usually reported, especially in athletes. In the acute phase, PCL tears are particularly difficult to diagnose at clinical examination and may go unnoticed even to a skilled clinician because of concomitant lesions to other structures, of hematrhos or of strong muscular defense. The PCL is responsible for 95% of biomechanical knee stability and therefore plays a major role in the maintenance of joint congruence. In the long run, PCL tears cause posterolateral instability and an untimely development of degenerative changes, particularly at the patella. Site and grade of PCL tears must therefore be accurately assessed to plan the most appropriate treatment and to avoid the abuse of arthroscopy, toward improving cost-effectiveness for public health structures. Nowadays, CT of the knee joint is performed more frequently than MRI because the former is more easily available, in agreement with the current Italian economic choices in the field of public health. CT allows the accurate identification of complete and partial PCL tears. In our series (765 patients), PCL tears were more common than reported in the literature (9.5% vs 5%); moreover, PCL tears were always associated with lesions in other structures--e.g., anterior cruciate ligament, menisci. In conclusion, the CT demonstration of the knee joint, together with the knowledge of the physiopathologic relationships among different structures, allows better understanding of painful syndromes of the anterior joint compartment, which are particularly common in athletes. These syndromes are usually caused by a femoro-patellar overload in people suffering from congenital ligament laxity, which may or may not be associated with abnormal knee morphotype--i.e., valgus, recurvatus.