How can we define clinically important improvement in pain scores after biceps tenodesis?

BACKGROUND

Patient postoperative pain is an important consideration following biceps tenodesis. The visual analog scale (VAS) for pain is one of the most commonly used measures for perioperative pain assessment. Currently, there is limited understanding of clinically significant improvement in VAS pain.

PURPOSE

To define the substantial clinical benefit (SCB), patient acceptable symptomatic state (PASS), and minimal clinically important difference (MCID) for the VAS pain score in patients undergoing open subpectoral (OSPBT) or arthroscopic suprapectoral biceps tenodesis (ASPBT) at 1 year from surgery; and to identify preoperative predictors of achieving each outcome end point.

METHODS

Data from consecutive patients who underwent isolated biceps tenodesis between January 2014 and March 2017 were collected and analyzed. Baseline data and postoperative patient-reported outcome (PRO) scores were recorded at 1 year postoperatively. In order to quantify the clinical significance of outcome achievement for the VAS pain score, the MCID, PASS, and SCB were calculated.

RESULTS

A total of 165 patients were included in the final analysis. The VAS pain score threshold for achieving MCID was defined as a decrease of 12.9 (0-100). PASS was defined as achieving a 2-year postoperative score of 27.4 points (0-100), and SCB was defined as a decrease of 25.1 (0-100) at 1-year follow-up. The rates of achieving MCID, PASS, and SCB were 73.3%, 52.8%, and 45.9%, respectively. Multivariate regression analysis demonstrated that ASPBT (P = .01) and a lower preoperative Constant-Murley score were predictive of achieving the MCID (P = .01). In contrast, a lower preoperative score on the SF-12 Physical Component Summary (P = .01) and a higher score on the preoperative American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (P < .001) were predictive of achieving the SCB and PASS, respectively. Preoperative duration of symptoms >6 months was predictive of a reduced likelihood to achieve PASS.

CONCLUSION

This study identified scores for VAS pain that can be used to define clinically significant outcome after biceps tenodesis. Specifically, a decrease in pain score of 12.9 was a clinically important improvement in VAS pain, whereas a decrease of 25.1 represented the upper threshold of VAS pain improvement. Additionally, there were both modifiable and nonmodifiable factors that predicted achieving clinically significant levels of postoperative pain improvement.