Retain or sacrifice the posterior cruciate ligament in total knee arthroplasty? A histopathological study of the cruciate ligament in osteoarthritic and rheumatoid disease

Abstract

Background-The decision whether to retain or resect the posterior cruciate ligament in total knee arthroplasty is at present determined clinically by preoperative radiological variables focusing upon the amount of joint destruction, and subsequent soft tissue contractures. However, these variables give only indirect information on the histological integrity and proprioceptive properties of the posterior cruciate ligament. Methods-Twenty posterior cruciate ligaments, obtained during total knee arthroplasty, were evaluated histologically to study the relation between the degree of preoperative radiological joint destruction, structural integrity of the posterior cruciate ligament and the neurological integrity of the targeted tissue. Eleven patients had osteoarthritis and nine patients rheumatoid arthritis. Haematoxylin and eosin, Alcian blue (mucoid degeneration), elastica von Gieson, Gomori (elastic fibres and collagen), and immunohistochemical staining for neural structures were used. Results-In all but one of the posterior cruciate ligaments, morphologically intact neural tissue was present in the peritendineum of the ligaments. Structural integrity of the collagen framework was present in only seven posterior cruciate ligaments. These cases all had grade three or four radiological joint destruction. In 13 of the specimens a certain degree of mucoid degeneration of collagen was present. All patients with grade five radiological knee joint destruction displayed mucoid degeneration and irregularity of the posterior cruciate ligament fibres. Conclusion-Because of the extensive architectural and probably functional damage of the posterior cruciate ligament in patients who have grade five radiological knee joint destruction, retention of the posterior cruciate ligament in knee prosthesis should not be advocated. (J Clin Pathol 2001;54:381-384)

An evaluation of the posterior cruciate ligament function in total knee arthroplasty with regard to its morphology and clinical properties

“…In these tests, it was found that the mucoid degeneration of the ligament was related to the stratification and destruction of collagen fibres. Similar changes have been described previously by Nelissen and Hogendorn [13] in 20 PCL samples taken during TKA. They report mucoid degeneration and abnormal course, with disturbances in the spatial structure of the collagen fibres.…”

“…They show nerve endings to be present in anterior cruciate ligament and PCL preparations, while also observing a reduction in the number of mechanoreceptors in degenerative diseases of the knee. The presence of proprioceptors in the PCL has been demonstrated by a number of authors using various staining methods [9,13]. Barrett et al [4] and Skinner et al [19] describe a weakening of proprioception to be associated with age and with greater degenerative disease.…”

Posterior cruciate ligament at total knee replacement

“…15 Mucoid degeneration of the fibres was frequently seen. Another study revealed that degeneration or rupture of the anterior cruciate ligament strongly reflected the histological state of the PCL.…”

Histological Changes and Neural Elements in the Posterior Cruciate Ligament in Osteoarthritic Knees

“…31 However, although most PCLs have an intact neural structure, extensive mucoid degeneration and irregular fibre pattern are noted. 32 Radiological grading of osteoarthritis matches the functional state of the PCL; therefore, PCL-retaining prosthesis should not be used in patients with osteoarthritis of greater than grade-5 severity. 32 The mechanical property of PCL as a physical restraint to posterior translation of the tibia is well established.…”