Eh? What's That You Say?
I bet I know a set of joints you’ve never heard of before: the ossicular joints.
They’re synovial joints, like the joints in your knees, elbows, shoulders, and knuckles (among others). Synovial joints are the hinge- or ball-and-socket joints that allow us to move: walk, bend at the hip and pick things up with our fingers, shrug a sweater on or off, play tennis, or chase a 3-year-old. Synovial joints mean we can swing our arms or run races or do jumping jacks.
How RA affects our joints
When it comes to rheumatoid arthritis/rheumatoid disease (RD), though, synovial joints are special in a darker way. RD tricks the body’s deadly serious, protective immune system into siccing confused-but-valiant soldier-antibodies on them. Misguided and lethal, the antibodies perceive the synovial tissues (which lubricate, cushion, and protect the joints) as enemies that must be destroyed at all costs.
You know what that means: if they’re not stopped, the antibodies cause inflammation, pain, and the eventual destruction and sometimes, deformity of the joint. More pain–and often, permanent disability–follows.
How … delightful. But back to the ossicular joints. Where are they, anyway?
What are the ossicular joints?
They’re in your ears. Yes, you heard that right. (Forgive me, please?) There are three tiny bones in the inner ear, lying directly behind the eardrum: the malleus (“hammer”), the incus (“anvil”), and the stapes (“stirrup”). Together they’re known as the middle ear ossicles, and without them, you can’t hear a dang thing.
The hammer connects to the eardrum; its other end connects, hinge-like, to the anvil. The anvil and stirrup bones hinge as well. Finally, the stirrup’s flat end connects to an oval opening in the cochlea, the horn-like, fluid-filled portion of the inner ear.
When a sound hits the amazingly sensitive eardrum, it vibrates and moves the middle ear ossicles. Like miniature levers, they cause the flat end of the stirrup to pump against the cochlea, sending waves of sound spiraling through to the brain.
Can RA affect hearing?
The connecting “hinges” between the hammer, anvil, and stirrup bones are actually minuscule synovial joints. As odd as it sounds, RD may attack even these, the smallest joints in the human body.
This misguided, self-destructive attack on the ossicular joints causes inflammation and swelling. It can also thicken the synovial fluid into a hard substance called pannus, causing deformity. All of this interferes with the free movement of those tiny ossicular hinges, keeping them from conducting sound as well as they should. Tinnitus (a constant ringing, hissing, or roaring sound in the ears), reduced or impaired hearing, or even deafness can result.
How common is this?
Fortunately, ear RD is rare, affecting only about 1 percent of patients. Studies show that in some patients, the auditory symptoms track right along with the course of their RD; they’re worse when it flares and get better when it abates.
Treating RA-related hearing loss
Treatment for symptoms of hearing loss related to RA is the same as for all the other synovial joints: treat the underlying disease with non-steroidal anti-inflammatory drugs (NSAIDs), traditional disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate, or biologic DMARDs.
As someone who’s endlessly curious, discovering that I have joints in my ears (!) delights me. That my RD can mess them up like it does my fingers, knees, and elbows is sobering, though. It never stops surprising me.
When was your last flare?