These doctors report cases of locking knees in two women during pregnancy. Joints are often looser during pregnancy. Increased weight on the joint can cause problems, especially if the woman has a history of previous knee injury.
Both of these women had knee injuries and a knee operation years before their pregnancies. They had no further knee problems until the pregnancy. The locked knee in the first woman turned out to be a tiny piece of cartilage and bone floating freely inside the joint. The second patient had a torn meniscus (cartilage) in the knee joint.
Surgery to remove the loose body and repair the torn meniscus was done. There were concerns about the unborn children. For this reason, a spinal anesthetic was used instead of a general anesthesia or local knee block. This means the patient was numb from the waist down instead of being asleep (as in general anesthesia) or having sensation to the knee blocked.
The authors also report the reasons why a spinal anesthetic was used. Not as much anesthetic is needed with a spinal anesthetic. Greater muscle relaxation is possible. If high stress must be placed on the knee, the patient won’t feel pain during the operation. Sometimes a local block to the knee is incomplete. If a pregnant woman feels any pain or discomfort, her blood pressure might go up. Doctors try to avoid this during pregnancy for the sake of the unborn child.
Surgery is usually avoided during pregnancy. Emergencies do come up, however. A locked and painful knee is one such emergency. Surgery can usually be done safely in these cases. Surgeons are advised to use a spinal anesthetic and fetal monitoring.
With a team approach, no harm is done to the baby. There’s only a one to two percent chance the woman will have a miscarriage.