Fluctuation of visual analog scale pain scores and opioid consumption before and after total hip arthroplasty

Patients who undergo orthopedic procedures are often given excess opioid medication. Understanding the relationship between pain and opioid consumption following total hip arthroplasty (THA) is key to creating safe and effective opioid prescribing guidelines.

To evaluate the association between the quantity of opioid consumption in relation to pain scores both pre-and postoperatively in patients undergoing primary THA.

We retrospectively reviewed patients who underwent primary THA from November 2018-May 2019 and answered both the visual analog scale (VAS) pain and opioid medication questionnaires pre-and postoperatively. Both surveys were delivered daily for 7-days before surgery through the first 30 postoperative days. Survey results were divided into preoperative, postoperative days 1-7, postoperative days 8-14, and postoperative days 15-30 for analysis. Mean opioid pill consumption and VAS pain scores in each time period were determined and compared to patients' preoperative status using hierarchical Poisson and linear regressions, respectively.

There were 105 patients included. Mean VAS pain scores were the highest preoperatively 7.41 ± 1.72. However, VAS pain scores significantly declined in each successive postoperative category compared to preoperative scores: postoperative day 1-7 (5.07 ± 1.79; P < 0.001), postoperative day 8-14 (3.60 ± 1.64; P < 0.001), and postoperative day 15-30 (3.15 ± 1.63; P < 0.001). Mean opioid pill consumption preoperatively was 0.68 ± 1.29 pills. Compared to preoperative opioid consumption, opioid use was significantly greater between postoperative days 1-7 (1.51 ± 1.58; P = 0.001) and postoperative days 8-14 (1.00 ± 1.27; P = 0.043). Opioid consumption declined below preoperative levels between postoperative days 15-30 (0.35 ± 0.72; P = 0.160) which correlates with a VAS pain score of 3.15.

All patients experienced significant benefit and pain relief from having undergone THA. Average postoperative opioid consumption decreased below preoperative consumption between postoperative days 15-30, which was associated with a VAS pain score of 3.15. These results can be used to appropriately guide opioid prescribing practices and set patient expectations regarding pain management following THA.