Question
I have suffered for the last 5 years from some unknown spondyloarthropathy – possibly ankylosing spondylitis. I’ve never received a definitive diagnosis from my rheumatologist; he’s just slowly eliminated the possibility of other diseases through testing. One of the symptoms that is most pronounced on me is oedema above and below all my major joints (knees especially). He has said that this is enthesopathy – inflammation at the point where ligaments and tendons attach to bone. Although I am greatful that I do not eroded or swollen joints, this inflammation of the tendons and ligaments is no less painful. The joints themselves do ache at times, but are not red or swollen. My concern now is that these attachment points could begin to erode the bone and cause deformity. My question is: Is this enthesopathy a symptom of AS? Should I be concerned about ankylosing joints – is this the beginning of the ankylosing process? My hips and shoulders have already lost some range of motion, is my spine next? I can already hearing the “popping” noise in my spine upon movement, that I usually in hear in my other joints. Is this noise actually the inflamed tendon sheaths? And is that what is causing the soft tissue swelling around the joints? And finally, what can be done to slow this process (over the short term to reduce the swelling and over the long term to prevent deformity)?
Answer
Enthesopathy as you correctly defined is inflammation where the tendons and ligaments attach onto bone. It commonly affects areas such as the achilles tendon insertion onto the heel or the plantar fascia insertion on the heel. It is a feature of the seronegative spondyloarthroapthies whihc include ankylosing spondylitis, psoriatic arthritis, reactive arthritis (Reiter’s) and enteropathic arthritis. The inflammation causes calcification in these areas, and rarely causes bony erosions. The calcifications on the tendons can cause the popping or grating sensation that you describe. Unlike the studies with RA, there have not been formal studies with medications on prevention of erosions and joint damage in these diseases. But, presumably, drugs like methotrexate, and the TNF inhibitors will be disease modifying in these diseases similar to their role in RA.