Purpose: To evaluate the influence of mild depression on pain perception after total knee arthroplasty (TKA).
Methods: Hamilton depression (HDRS) and numeric rating (NRS) scales were used to evaluate depression severity and pain perception at various intervals surrounding TKA. The Hospital for Special Surgery (HSS) knee and pain scores (NRS) in patients with signs of mild depression (HDRS < 20 points) were compared to a control group of patients with no signs of depression (HDRS < 8 points).
Results: Prior to surgery, there were no statistical differences in pain perception (NRS) or individual components of HSS knee score including range of motion, pain, and function between patients with mild depression compared to controls. However, following surgery, patients with signs of mild depression were more likely to report more pain (p < 0.001) and have lower HSS scores even at 1 year post-operatively (p < 0.001).
Conclusions: A significant number of patients in this series undergoing routine primary TKA had signs of subclinical depression. These patients are more likely to report increased pain even at 1 year following surgery compared to patients without signs of depression preoperatively. Psychometric evaluation prior to surgery can help identify the at-risk patient and allow for proper management of patient expectations, thus improving clinical results and patients' satisfaction after TKA.
Level of evidence: Prospective comparative study, II.
Keywords: Depression; Pain; Results; Total knee arthroplasty.