Summary

Medial collateral ligament as a synovio-entheseal complex has an important role in the initiation of osteoarthritis of the knee.

Abstract

Introduction

Recently, it has been suggested that inflammation in the collateral ligament is important in the pathogenesis of osteoarthritis. The medial collateral ligament of the knee is known to function as a synovio-entheseal complex. However, MRI scoring system such as whole organ magnetic resonance score (WORMS) has little interest in ligament. The present study is to clarify the characteristics of medial collateral ligament complex in osteoarthritic changes based on MRI imaging findings in patients with osteoarthritis of the knee.

Methods

Seventy-nine patients with 82 knees (mean age 55.7±10.8 years old) who presented with non-traumatic medial knee pain between April 2018 and March 2021 were included and divided into two groups: the Early OA group(Kellgren-Lawrence grade 0,1) was 36 knees (male 8, female 28; mean age 50.1±10.5 years old), and the Advanced OA group (Kellgren-Lawrence grade 2, 3, 4) was 46 knees (male 8, female 36; mean age 61.4±12.3 years old). The prevalence of the eight MRI findings proposed by the OMERACT MRI in Enthesitis Initiative were compared between groups.

Results

Overall, there was a prevalence of peri-ligament hypersignal (95%) and osteophyte (81%), bone marrow edema (56%), intra-ligament hypersignal (52%), Eetheseal thickening (38%), intra-ligament Hypersignal on T1 wighted view, bursitis (12%), and bone erosion (6%). the Early OA group had a similarly high prevalence of peri-ligament hypersignal (92%), but a lower prevalence of osteophyte (58%).

Conclusion

Inflammation of the medial collateral ligament complex may be one of the etiologies of early osteoarthritis of the knee.