@pmcallister May I suggest a visit to a Physical Therapist who specializes in Rehabilitation - these are usually affiliated with a trauma center or orthopedic hospital.
When you have joints replaced and/or back surgery, your body mechanics change. This can cause limping, an odd gait, balance issues, even toes turning in or out. Why? The replacement of worn joints changes your body mechanics, and your brain and body need to be retrained.
What helped me was an full evaluation, gait and balance training and specific strengthening exercises - all done by rehab therapists (highly trained PTs) who specialized in trauma cases, limb loss, post stroke recovery and more. It took about 3-4 months working with them, and continuing the exercises on my own for about 3 more months.