Hip pain after replacement when laying on it

I had a total hip replacement in 2006. I've been experiencing pain on that side when sleeping on it. Before it never hurt or hurt minimally but now it hurts all the time after I roll off of it. What is the cause of this? I am a side sleeper and can not sleep on my back or stomach.

[Christopher R Newey, DO]

Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with a doctor.

Without the ability to examine and obtain a history, I can not tell you what the exact cause of the symptoms is. However I will try to provide you with some useful information.

Is the pain on the inside of the hip or outside? If the pain is on the inside of the thigh, it may be a condition where the nerve is entrapped. This nerve is the obturator nerve. This may happen during hip surgeries because of its vulnerable location. If it does become entrapped, it will produce pain from the groin down the inner thigh. There may also be weakness with bringing the thighs together against resistance.

Another condition that can cause pain on the outside of the thigh is from entrapment of a nerve called the lateral femoral cutaneous nerve. It can become entrapped in pregnancy, obesity, or from direct compression, fracture of the front part of your pelvis, or too much rotation of the pelvis anteriorly.

I do recommend seeing a neurologist. He/she will be able to do a formal neurological examination which includes motor and sensory testing as well as reflexes. The examination and history are important in localizing the problem. He/she may wish to obtain structural (e.g., MRI) and/or electrophysiology (e.g., EMG/NCS) testing.

Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.