Correlation of Cruciate Ligament Histological Findings with Coronal Plane Deformities and Characteristics of Patients Undergoing Total Knee Arthroplasty

Introduction: Osteoarthritis (OA) is a leading cause of disability in older adults. The majority of cruciate ligament injuries progress to OA through numerous mechanisms. The aim of this study was to identify the histological changes of cruciate ligaments in OA knees from patients undergoing total knee arthroplasty (TKA) as well as possible correlations with coronal plate deformities and patients’ characteristics. Methods: A total of 50 consecutive patients with knee OA undergoing TKA with posterior stabilized prosthesis were included in the study. Demographics, preoperative range of flexion, the flexion contracture, Visual Analogue Scale (VAS) score, coronal plane deformity, Kellgren and Lawrence radiological degree of OA and Beguin-Locker classification of intraoperative degree of OA were recorded. The histopathological changes evaluated in specimens from both cruciate ligaments included myxoid and mucoid degeneration, chondroid metaplasia and orientation of collagen fibers. Results: A total of 24 males (48%) and 26 females (52%) with a mean age of 71 years (SD 5.93) participated in our study. The mean preoperative duration of pain was 3.62 years (SD 2.2). The K-L scale mean score was 2.60 (SD 0.64) and the mean VAS score 6.38 (SD 1.1). The mean varus deformity was 10.14 degrees (SD 3.7). Knee flexion/flexion contracture were recorded at 95.76±6.183 and 16.14±4.914 degrees, respectively. Intraoperatively, the B-L scale mean score was 2.02 (SD 0.77). Mucoid degeneration in ACL was the most common histopathological feature (15.7%) (SD 12.9), followed by chondroid metaplasia in both ACL and PCL [14.3% (SD12.5) and 14.3% (SD 13.2), respectively]. A negative correlation between BMI and myxoid ACL (p=0.01) as well as between varus deformity and mucoid ACL (p=0.05) was found, while a negative correlation between height and myxoid ACL (p=0.05) has been also revealed. Conclusion: Degeneration of cruciate ligaments is associated with degenerative joint disease and OA should be considered a disease involving the whole joint including ligaments, menisci, synovium and joint capsule. However, the correlation between degeneration of cruciate ligaments and OA is not yet fully understood and more research is needed