PROSPECTIVE CLINICAL STUDY OF POSTERIOR CRUCIATE AND MENISCOFEMORAL LIGAMENTS OF THE KNEE JOINT FROM SURGICAL BIOPSIES AND MORPHOMETRIC ANALYSIS FROM THIEL EMBALMED KNEES

Abstract

Despite recent advances in management, knee pain and instability after TKA remains problematic. Lack of data of whether TKA PCL sacrificing or retaining procedure proper for painfree or painful knees during surgery. Preoperative parameters predict degeneration of the PCL and MFLs, and therefore can be used to determine TKA procedure. The current study aimed to evaluate the detailed macroscopic and microscopic degenerative changes within the knee, including the neural structures, in relation to preoperative clinical assessments to predict postoperative degenerative changes of the posterior cruciate ligament (PCL), anterior meniscofemoral ligament (aMFL) and posterior meniscofemoral (pMFL).

A macroscopic study was conducted by dissecting 80 Thiel embalmed knees in the Centre for Anatomy and Human Identification from 21 males and 19 females with an age range 47 to 100 years. From these the length, width and footprints were evaluated to determine the anatomical variation of the PCL, aMFL and pMFL. In addition, microscopic examination was conducted on 37 patients (21 males and 16 females aged 57 to 90 years) at Ninewells Hospital and Perth Royal Infirmary Hospital who underwent a TKA PCL sacrificing procedure to enable a histopathological and immunohistochemical analysis of the PCL, aMFL and pMFL.

Having identified the macroscopic morphology of the ligaments and bony structures, and microscopic collagen fibres and neural structures, there was no significant difference between sides for both the macroscopic and microscopic analyses, however a sex difference was observed for some macroscopic measurements. Also, in the male and female specimens, the PCL PMB was larger than the PCL ALB; in addition, an aMFL was more common than a pMFL, with both being present in more than 84% of knees examined. There was an increase in degenerative changes observed with increasing age.

The preoperative radiological assessment was not a useful predictor of postoperative degenerative changes. However, based on the preoperative pain score pain free knees with both varus and valgus showed moderate collagen disorientation and mucoid degeneration with fewer neural structures within the ligament compared to painful knees. Furthermore, for painful knees, severe collagen disorientation with moderate mucoid degeneration and more neural structures were present in valgus than varus knees.

In conclusion, there is the potential of macroscopic and microscopic examination outcomes of the PCL, aMFL and pMFL being useful for their preservation during TKA in case of preoperative pain free knees, use in association with the patient clinical profile. Otherwise a TKA sacrificing procedure appears to be the only option in cases of preoperative painful knees.