Does Being Pregnant Cause Thumb Arthritis Later in Life?
Does being pregnant cause thumb arthritis later in life? Thumb arthritis can be associated with capsular ligament laxity. What does that mean? The ligaments that hold the base of the thumb joint together (CMC joint), help to guide the joint surfaces to allow smooth movement. When they get loose from wear and tear or injury, this can cause a sloppy CMC thumb joint and can lead to pain and arthritis. I blogged on loose thumb ligaments causing arthritis a while back. The Hormone Relaxin is produced by both women and men and causes ligaments to become looser. It spikes in women at the mid-point of every menstrual cycle and then really increases if pregnancy follows. The role of the hormone in pregnancy is to allow the ligaments surrounding the birth canal to be very loose, so the canal can expand to accommodate the baby’s head. This morning a new study shows that elevated Relaxin ligament receptors are elevated in non-pregnant women and are associated with thumb arthritis and the bad chemicals in joints (MMPs) that are believed to be causative in arthritis. The study authors looked at about 50 patients who were undergoing thumb joint surgery for arthritis and measured joint laxity. The women had more laxity in the joint. They also had more receptors for the hormone Relaxin in the thumb ligaments and more MMPs in the joint. The study only found correlations, which aren’t the same as being able to firmly state that one thing causes another, so more research is needed. However, this does raise some interesting questions about other problems like chronic SI joint instability and whether certain women over express receptors for the hormone Relaxin in their ligaments and end up with arthritis due to chronic ligament laxity later in life. The upshot? Ligament laxity is a major problem in thumb and other joint arthritis that few physicians identify and even fewer treat. Are your joints unstable and is that what’s causing your arthritis? Regrettably for most patients, a simple physician exam looking for busted ligaments that can be surgically replaced will never answer that question.