If you're considering a hip replacement please read.
Back in 2013 both my hips were replaced and left me with some problems. To begin with the right hip has suffered calcification of the soft tissue (heterotopic ossification). It hasn't gotten any worse after the first year and I've learned to mitigate the stiffness it causes through exercise, cycling and an occasional deep tissue message.
The other problem caused by the replacement is the atrophy of the medial head of the Gastrocnemius of my calf muscles. It took a long time to recognize the problem. I've concluded that there is nothing I can do on my own to build up the muscle. I can't get that part of the Gastrocnemius to fire up. It seems that the nerves were damaged to that part of muscle. It might been caused by the torture table that was used to rotate the hips open as part of the anterior hip replacement procedure. Severe twisting of the lower leg to open the hip joint is my guess as to what caused the damage.
For now I've become used to the situation and it has no pronounced effect on cycling as long as long as I'm clipped in to the pedals. The Gastrocnemius attaches to the back base of the Femur. Along with the less powerful Soleus muscle which attaches to the top and back of the Fibular the Gastrocnemius and Soleus comprise the primary muscles of the calf. So I still have enough strength to stabilize the lower leg and ankle. However walking is a little funky.
I would think twice about doing the Anterior hip replacement again if I had more hips to replace.