Final answer:
The ideal age for performing an HTO is generally between 40 and 60 years and depends on several patient-specific factors, including the degree of unicompartmental knee osteoarthritis and overall joint health.
Step-by-step explanation:
The inflection age for performing a High Tibial Osteotomy (HTO) on a patient for unicompartmental arthritis is not strictly defined because it is based on individual patient factors. However, HTO is typically considered for younger patients, possibly between 40 and 60 years of age, who are active and wish to delay or avoid a total knee replacement. The main consideration is that the patient should have unicompartmental knee osteoarthritis with an intact anterior cruciate ligament and a correctable malalignment with minimal to no arthritis in the other compartments.
Age is the chief risk factor for osteoarthritis, with evidence of OA by age 65 in as many as 80 percent of all people. However, prior joint injury, congenital malformations, excess body weight, and genetic factors can also significantly influence the development of OA and subsequently the consideration for HTO. Factors that would potentially qualify a patient for HTO include the degree of pain, level of activity, alignment of the joint, and quality of the adjacent knee joint cartilage.