When osteoarthritis affects the knee, uneven wear and tear can occur. One side of the joint can wear down more than the other. The knee may angle to one side, causing either a knock-kneed (valgus) or bow-legged (varus) problem. A valgus knee puts more pressure on the inside edge of the knee. A varus knee puts a greater load on the outside. This transfer of load can actually make the arthritis worse.
Someone who is young and active with arthritis only on one side of the knee may not want or need to have the entire joint replaced. Treatment options include removing a piece of the thighbone just above the knee (femoral osteotomy), replacing just one side of the knee joint (partial knee replacement), or replacing the entire knee joint (total knee replacement).
Doctors try to choose the treatment that will save the joint for as long as possible. Sometimes an osteotomy is the best short-term option, but a joint replacement is needed later. This study reviews the results of 11 knee joint replacements in nine patients who had a past femoral osteotomy.
Most of the patients (seven out of 11) had excellent to good results. The success was based on improved range of motion, decreased pain, better function, and better alignment of the knee. The four patients who only had a fair result had knee pain or an unstable knee.
The authors make several summary statements: