GUIDELINE FOR WAIT TIME THRESHOLDS FOR TOTAL HIP AND KNEE REPLACEMENT SURGERY BASED ON SEVERITY

Abstract

The purposes of this study were to determine the effect of severity, wait times and patient perspective on outcomes and to create an eivdence-based prioritization tool.

Patients who received a primary hip or knee replacement were followed forward from decision date for surgery to one-year follow-up (N = 4437) and outcomes assessed according to baseline severity. At decision date for surgery, patient baseline severity was captured using the WOMAC disability questionnaire. Twelve to eighteen months after surgery, a questionnaire (WOMAC, satisfaction) was sent to patients to compare pre- and post-operative data.

The chance of a good outcome from TJR surgery gets worse as wait times get longer. Baseline severity affects outcome more than wait times. Patients with a baseline WOMAC less then 30/100 should have surgery within three months (20% patients) If surgery cannot be done within three months, then three priority levels are recommended: Priority I – One month maximum: catastrophic hip or knee joint conditions – complications that are an immediate threat to independence. Priority II – three months maximum: extreme pain and disability because of hip or knee joint condition that will be a threat to role and independence within three months (baseline WOMAC less than or equal to 30/100). Priority III – six months maximum: severe pain or disability because of hip or knee joint condition, but role and independence not threatened (baseline WOMAC over 30/100).

The priority levels and wait time thresholds recommended in this study are the result of an analysis of pre-operative severity scores, the length of the wait and post-operative outcomes and are consistent with data from other sources.