Joint Replacement Candidacy Calculator

No -- it is this calculator's own weighted composite of pain, function, radiographic grade, failed conservative treatment, and age, not a published instrument endorsed by AAOS or any other professional body. The individual components it draws from (VAS pain scoring, Kellgren-Lawrence radiographic grading) are standard measures used in real orthopedic practice, but their combination into a single 0-100 number here is this calculator's own construction.

No -- the candidacy score is built entirely from pain, functional limitation, radiographic grade, months of failed conservative treatment, and age. BMI and comorbidity count instead feed the separate surgical risk level and the estimated length of hospital stay, reflecting that perioperative risk and candidacy for surgery are related but distinct questions.

This calculator allocates pain severity up to 30 of the 100 possible points, more than any other single factor including the 20 points allotted to radiographic (Kellgren-Lawrence) grade. That reflects a common clinical emphasis in real decision-making: imaging alone doesn't determine whether surgery is warranted, since patients can have significant radiographic changes with limited symptoms, or significant pain with only moderate imaging findings.

Because the relationship between age and joint replacement benefit isn't linear. This calculator awards its highest age sub-score to the 55-80 range, where surgery is typically considered most beneficial relative to perioperative risk, a somewhat lower score to patients over 80 (still beneficial but carrying more surgical risk), and the lowest scores to younger patients, where conservative management is often tried longer first given a joint replacement's finite implant lifespan.