It sounds like you have been diagnosed with a condition called medial compartment osteoarthritis (MCOA). MCOA affects just one side of the joint — medial refers to the side closest to the other knee.
Anyone with chronic knee pain who has been evaluated by an orthopedic surgeon and diagnosed with early stages of degenerative arthritis can begin with conservative (nonoperative) care. Activities can be modified to reduce stress and load on the joint. Weight loss is advised for anyone who is overweight. Physical therapy to improve posture, alignment, motion, and strength is often helpful.
Misalignment of the hip, knee, and/or ankle leading to an uneven weight distribution contributes to the development of medial compartment osteoarthritis (MCOA). When the joint is worn down to the end-stages of arthritis, then surgery is often required. Surgery to correct the problem consists of: tibial osteotomy (HTO), unicompartmental knee arthroplasty (UKA), or total knee replacement (TKR).
Tibial osteotomy refers to a surgical procedure where the surgeon removes a wedge-shaped piece of bone from one side of the tibia (lower leg bone). The goal of an osteotomy for medial compartment osteoarthritis (MCOA) is to shift the weight off the medial side of the joint. By shifting the weight-bearing load, the medial joint surface gets a break and the tension on the knee ligaments is corrected.
Unicompartmental arthroplasty is the replacement of the diseased side of the joint with an implant. The device is much like a total knee replacement but only involves one-half the joint. Of course, a total knee replacement removes the entire joint surface on both sides and replaces it with a metal or ceramic joint.
It’s best to talk with your orthopedic surgeon to find out what he or she would recommend. Your age, activity level, type of joint involvement, and any alignment issues contributing to this problem can all make a difference as to which treatment approach is best for you.