How Can We Define Clinically Important Improvement in Pain Scores After Hip Arthroscopy for Femoroacetabular Impingement Syndrome? Minimum 2-Year Follow-up Study

Abstract

Background: Patient postoperative pain is being increasingly reported in the field of hip preservation surgery. The visual analog scale (VAS) for pain is one of the most commonly utilized measures for perioperative pain assessment. Currently, there is limited understanding of clinically significant improvement in VAS pain. Purpose: (1) 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 hip arthroscopy for femoroacetabular impingement syndrome after 2 years from surgery and (2) to identify preoperative predictors of achieving each outcome endpoint. Study Design: Case series; Level of evidence, 4. Methods: Data from consecutive patients who underwent primary hip arthroscopy between November 2014 and March 2017 were collected and analyzed. Baseline data and postoperative patient-reported outcome scores were recorded at 2 years postoperatively. To quantify clinical significance of outcome achievement for the VAS pain score, the MCID, PASS, and SCB were calculated. Results: A total of 976 patients were included in the final analysis. The VAS pain score threshold for achieving the MCID was defined as a decrease of 14.8; the PASS was defined as achieving a 2-year postoperative score of 21.6 points; and the SCB was defined as a decrease of 25.5 or a score of 15.4 points at 2 years. The rates of achieving the MCID, PASS, and SCB were 97.6%, 66.4%, and 71.2%, respectively. Regression analysis demonstrated that sports involvement, low body mass index, smaller preoperative alpha angle, and absence of articular damage and chondromalacia were predictive of achieving the PASS (all P < .05). Preoperative predictors for achieving the SCB included being male, no smoking history, smaller alpha angle, higher modified Harris Hip Score, and lower VAS pain score (all P < .05). Conclusion: This study identified scores for VAS pain that can be used to define clinically significant outcome after arthroscopic treatment of femoroacetabular impingement syndrome. Specifically, a decrease in pain score of 14.8 was a clinically important improvement in VAS pain, while an absolute score <15.4 or a change of 25.5 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.

What is the Role of Kinesiophobia and Pain Catastrophizing in Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome?

“…43 MCID for the HOS-ADL, HOS-SS, mHHS, and iHOT-12 was determined by calculating the ½ standard deviation of each PROM mean in the study patients, as described in the literature. [44][45][46] When describing achievement of clinically significant outcome, it is generally accepted that this is defined as achievement of MCID on any hip-specific outcome measure. 47,48 The burden of MCID achievement across all outcome measures may not be realistic, given that each outcome measure may represent a separate outcome domain.…”

“…49 Our methodology here is in line with adopted and accepted FAI, KINESIOPHOBIA, AND PAIN CATASTROPHIZING e99 methods previously reported and supported in the literature. 45,[49][50][51][52] Statistical Analysis All data were screened to determine whether parametric statistical assumptions were met before analysis. In cases of parametric analysis violation, the nonparametric analogue tests were applied.…”

Outcomes of Preoperative Opioid Usage in Hip Arthroscopy: A Comparison With Opioid-Naïve Patients

“…Many authors use the MCID and PASS as a gauge for clinical relevance when determining the significance of their outcomes. 12,15,[17][18][19] Although most percentages of patients achieving MCID and PASS after hip arthroscopy range from 60% to 95% based on the specific score used, 14,17 to our knowledge, no study has used this tool to compare outcomes between opioid-naïve and non-naïve patients undergoing hip arthroscopy. In our study, we demonstrate that opioid-naïve patients are not only statistically more likely to reach the MCID and PASS with regards to the VAS, but also reach these values at an earlier postoperative period.…”

“…The MCID represents the smallest difference that patients perceive as beneficial 10 and PASS represents the threshold for clinical improvement. 11 Established values of an increase in 8 points for the MHHS, 12 10 points for the NAHS, 13 and a decrease of 1.48 points for the VAS 14 were used. PASS has an established value of 74 points on the MHHS 15 and 2.16 on the VAS.…”

Editorial Commentary: Quantifying Patient Satisfaction After Hip Arthroscopy: I Cannot Deactivate Until You Are Satisfied With Your Care

“…Dr. Nho and his colleagues have worked diligently over the past 4 years to establish the MCID, SCB and PASS thresholds for hip-preservation procedures and for hip-related patient-reported outcome measures (PROMs). [4][5][6][7][8][9] Previously establishing these values for young-adult hips, they have shown that 80% of patients achieve significant functional improvements at 2 years following femoral acetabular impingement syndrome (FAIS) surgery. 5 With their latest work, they now establish the MCIDs, SCBs and PASSs for the visual analog scale (VAS) satisfaction score.…”