Abstract
The relationship between pain catastrophizing and emotional disorders including anxiety and depression in patients with hip or knee osteoarthritis undergoing total joint replacement (TJR) is an emerging area of study. The purpose of this study was to examine the association between catastrophizing, anxiety, depression and postoperative pain and functional outcomes following primary TJR.
A prospective cohort study of preoperative TJR patients at one academic arthroplasty centre over a one-year period was conducted. Pain catastrophizing was assessed using the Pain Catastrophizing Scale (PCS), and anxiety/depression using the Hospital Anxiety and Depression Scale (HADS-A, HADS-D) at preoperative assessment. Postoperative outcomes at one-year included patient perceived level of hip/knee pain using a visual analogue scale (VAS), subjective perception of function using the Oxford Hip/Knee Scores, and objective function using the Knee Society Score (KSS) and Harris Hip scores (HHS). Median regression was used to assess pattern of relationship between preoperative PCS clinically relevant catastrophizing (CRC), abnormal HADS-A, abnormal HADS-D and postoperative outcomes at one-year. Median difference and 95% confidence interval (CI) were reported. T-tests were performed to determine mean differences in postoperative outcomes among patients with PCS CRC, abnormal HADS-A, and abnormal HADS-D scores versus those with normal scores at preoperative assessment. P-values less than 0.05 were considered statistically significant.
The sample included 463 TJR patients (178 hips, 285 knees). Both the PCS-rumination CRC sub-domain (median difference 1, 95% CI 0.31–1.69, p=0.005) and abnormal HADS-A (median difference 1, 95% CI 0.36–1.64, p=0.002) were identified as significant predictors of one-year VAS pain. PCS-magnification CRC sub-domain was also identified as a significant predictor of KSS/HHS at one-year (median difference 1.3, 95% CI −5.23–0.11, p=0.041). Preoperative VAS pain, Oxford and HHS/KSS scores were significantly inferior in patients who had CRC PCS, abnormal HADS-A, and abnormal HADS-D scores compared to patients with normal scores. At one-year, PCS CRC patients also had significantly inferior VAS pain (p=0.001), Oxford (p < 0 .0001) and KSS/HHS (p=0.025). Abnormal HADS-A and HADS-D patients experienced significantly inferior postoperative VAS pain (HADS-A p=0.025, HADS-D p=0.030), Oxford (HADS-A p=0.001, HADS-D p=0.030), but no difference in KSS/HHS (HADS-A = 0.069, HADS-D = 0.071) compared to patients with normal PCS/HADS scores. However, patients with CRC PCS experienced significantly greater improvement in preoperative to postoperative VAS pain (p < 0 .0001), Oxford (p=0.003) and HHS/KSS (p < 0 .0001). Similarly, patients with abnormal HADS scores showed significant improvement in preoperative to one-year postoperative change scores, as compared to normal patients in VAS pain (HADS-A p=0.011, HADS-D p=0.024), KSS/HHS (HADS-A p=0.017, HADS-D p=0.031), but not Oxford (HADS-A p=0.299, HADS-D p=0.558).
Patients who are anxious, depressed or who pain catastrophize have worse preoperative function and pain. Postoperatively, pain and functional outcomes are also inferior in such patients, however they do experience a significantly greater improvement in outcomes. Furthermore, it appears that rumination and anxiety traits predict pain levels postoperatively. Although these patients report higher levels of pain postoperatively, as compared to preoperative, great improvement can be expected following hip and knee TJR.
