Factors for persistent pain following total knee arthroplasty
Degenerative joint disease, particularly knee osteoarthritis (OA), is one of the most prevalent and disabling chronic pain conditions and is projected to increase sharply as the U.S. population ages. Projections also indicate that the annual number of total knee replacements, the treatment of choice for end-stage knee OA, will increase over the next several decades.
After surgery, half of patients experience moderate or severe pain in the first days and this pain may become even worse once rehabilitation is started. Therefore, effective pain control is important for optimizing the rehabilitation process in order to achieve patient satisfaction with a good functional outcome as well as reduce hospitalization length and costs. In this context, a study was carried out at the Russian Research Institute of Traumatology and Orthopedics n.a. R.R. Vreden (Vreden’s Institute) in St. Petersburg, Russia to explore sociodemographic, clinical and surgical factors in relation to pain trajectories during the first 3 postoperative days following total knee arthroplasty.
Preoperative pain was assessed the day before surgery, and acute postoperative pain was assessed using a 4-day pain diary, Patients rated their acute postoperative pain every evening starting on the day of surgery and continuing through Day 3. Six different aspects of pain were rated (i.e., worst, average, least, with activity, at rest, and duration), but this analysis emphasizes pain with activity and pain duration given their potential to impact physical rehabilitation.
All pain ratings decreased in the three days following knee surgery. Similarly, the reported number of hours per day in moderate/severe pain decreased over time. Women reported more pain than men. Patients who had a moderate to severe level of preoperative pain also reported more hours of moderate to severe pain during the first 3 postoperative days and surgeries longer than 90 minutes were associated with more postoperative pain in activity, as well as more hours of moderate to severe pain. Various studies indicated that patients who are depressed preoperatively have worse results after TKA surgery in terms of pain, functionality, and satisfaction.
This study evaluated a variety of different psychological and clinical preoperative patient characteristics and found that only female gender and higher levels of preoperative anxiety and pain were associated with higher levels of pain reported in the early postoperative period after TKA.