We aimed to determine how preoperative anxiety, depression, and locus of control (LoC) might predict patient outcomes following total knee arthroplasty (TKA).
Patients undergoing TKA were prospectively recruited over an 18-month period. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to assess TKA outcomes. The Short Form-12, Hospital Anxiety and Depression Score, and LoC surveys were completed by the patients to assess their psychosocial state. These scores were collected preoperatively and at 6 weeks, 18 weeks, and 1 year postoperation.
The final cohort consisted of 136 patients. Greater preoperative depression (P = .004) and anxiety (P = .001) scores were correlated with worse total WOMAC score at 6 weeks and 18 weeks postoperatively, respectively. A poorer preoperative Short Form-12 mental score was also correlated with a worse total WOMAC score at 6 weeks postoperatively (P = .007). Greater tendency toward an internal LoC preoperatively was correlated with better WOMAC pain (P < .001) and function (P = .003) scores at 18 weeks postoperatively. However, there was no correlation between preoperative external LoC and postoperative WOMAC score. There was also no correlation between any of the preoperative psychosocial measures and WOMAC score at 1 year postoperatively.
We identified a group of patients whose psychosocial markers predicted them to have worse outcomes in the short to medium term even though they normalized to satisfactory outcomes at 1 year postoperatively. Identifying this group could allow for targeted intervention with an adjustment of expectations and thus more effective recovery.