Knee Ligament Abnormalities in OA
Osteoarthritis (OA) of the knee most commonly occurs in the lateral medial compartment – that is the outside inside section of the joint – and can be associated with varus malalignment (that is, with a bowlegged appearance). Likewise, lateral compartment OA can be associated with valgus malalignment (that is, arthritis in the outside compartment is associated with a knock-kneed appearance). The ligaments on the inside and outside of the knee help to hold the knee in stable alignment, and abnormalities in these ligaments have been linked with the presence of osteoarthritis. Abnormalities in the ligaments found in the outside compartment (lateral collateral ligament complex or LCLC) are commonly seen in people with knee OA.
What Problem Was Studied?
Researchers from Johns Hopkins University Hospital in Baltimore, MD, and Thomas Jefferson University Hospital in Philadelphia, PA, noticed in their radiology practices that many people with OA also showed changes in the ligaments found in their LCLC in magnetic resonance images (MRIs). The research team, led by Yung-Hsin Chen, MD, set up a study to determine the features and prevalence of these abnormalities in people with and without OA.
What Was Done In the Study?
The study consisted of 96 participants, 51 with knee OA and 44 with knee pain but no history of knee OA. Each participant underwent an MRI. “The patients were graded on the severity of knee OA on radiographs [X-rays] and the severity of abnormalities of the LCLC components on MRI,” said Dr. Chen.
What Were the Study Results?
Dr. Chen and team identified LCLC abnormalities in 84% of the patients with OA compared to 25% of patients without OA. The study revealed that lateral compartment OA was most significantly associated with abnormalities in the fibular collateral ligament, followed by associations with the bicep femoris tendon and popliteus tendon.
What Do These Results Mean to People With Knee Pain?
Caution should be given to the interpretation of LCLC abnormalities, as they may be considered a feature of OA and should not be incorrectly attributed to an acute traumatic injury, say the study authors. “The results of the findings will help to explain some of the common findings we come across in day to day radiology in patients with osteoarthritis,” said Dr. Chen.