Relation of Hand Enthesophytes with Knee Enthesopathy: Is Osteoarthritis Related to a Systemic Enthesopathy?

Abstract

Objective Enthesopathy has been reported as a feature of osteoarthritis (OA) in the distal interphalangeal (DIP) joints. We previously reported that central bone marrow lesions (BML) on magnetic resonance imaging (MRI) scans are associated with OA. In this study, we evaluated whether hand and knee enthesopathy were related. Methods We studied knee and hand radiographs of subjects from the Framingham Osteoarthritis Study. Subjects seen in 2002–2005 had bilateral posteroanterior hand radiographs, weight-bearing knee radiographs, and knee MRI scans. Hand radiographs were read for enthesophytes at the juxtaarticular non-synovial areas of metacarpophalangeal (MCP), proximal interphalangeal (PIP), and DIP joints, and midshafts of the phalanges. We selected 100 cases of knees with central BML and 100 matched controls. Conditional logistic regression was used to assess associations. Results Subjects with enthesophytes of at least 1 score ≥ 2 at DIP, PIP, and/or MCP were not more likely to have central knee BML (OR 0.49, 95% CI 0.17–1.40) than those without enthesophytes. Similarly, having at least 1 score ≥ 2 on the shafts was not significantly associated with having a central knee BML (OR 0.59, 95% CI 0.23–1.51). Adjustment for the presence of diabetes mellitus did not affect these results, but there was an increased prevalence of diabetes in those with hand enthesophytes (OR 3.09, 95% 1.29–7.40, enthesophyte score ≥ 2). Conclusion We found no increase in the prevalence of hand enthesophytes among persons with central knee BML on their knee MRI scans. This provides evidence against a systemic enthesopathic disorder in association with knee OA.

The Puzzle of Generalized Osteoarthritis (OA) — Is OA a Systemic Enthesopathy?

“…The results from the current study do not support OA as a systemic enthesopathy 9 , and the enthesopathic changes seemed to be more related to local "wear and tear" and biomechanical stresses.…”

“…Further, one cannot rule out that the observed association is due to common environmental risk factors for hand and knee OA. In this issue of The Journal, Gibson, et al explore the concept of generalized OA and ask whether the disease is related to a systemic enthesopathy 9 .…”

“…Gibson, et al have performed a matched case-control study comparing the frequency of hand enthesophytes in participants with and without central BML in the knees 9 . The participants were recruited from the Framingham Offspring and Community Cohorts, and were not selected based on the presence of knee symptoms or radiographic OA.…”

Knee Enthesitis and Synovitis on Magnetic Resonance Imaging in Patients with Psoriasis without Arthritic Symptoms

“…The other important finding is the presence of villous projections, which is in our opinion an early phase for pannus formation, reflecting the early inflammatory process. In recent work Gibson and coworkers 20 observed no increase in the prevalence of hand enthesophytes among patients with knee BME on MRI scans. This in turn provides evidence against a systemic enthesopathic disorder in association with knee OA.…”

Dr. Gibson and Dr. Felson reply

“…We appreciate the interest from Tan and McGonagle 1 regarding our article 2 , as we recognize their expertise in this subject. To clarify, we did include enthesophytes at the distal interphalangeal (DIP), proximal interphalangeal (PIP), and metacarpophalangeal joints, and did not limit examination to the shafts as suggested in their letter.…”