Clinically Relevant Thresholds in Patient-Reported Outcomes: Do Patients’ Expectations Evolve Over Long-term Follow-up?

Abstract

Background:

Clinically relevant thresholds have been utilized to provide insight into postoperative functional status and patient satisfaction.

Purpose:

To define and evaluate the minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and substantial clinical benefit (SCB) thresholds over the 2-, 5-, and 10-year timepoints for the modified Harris Hip Score (mHHS), Hip Outcome Score–Sports-Specific Subscale (HOS-SSS), and International Hip Outcome Tool (iHOT12).

Study Design:

Case series; Level of evidence, 4.

Methods:

Data were retrospectively reviewed for patients who underwent primary hip arthroscopy from 2008 to 2021. The inclusion criteria comprised complete patient-reported outcome scores with anchor questions at the 2-, 5-, or 10-year timepoints. Groups were propensity score–matched 1 to 1 to 1 for these 3 timepoints to limit confounding variables. The PASS, SCB, and MCID thresholds were defined using the anchor-based method for the mHHS, HOS-SSS, and iHOT12.

Results:

A total of 414 hips were included in the study. Area under the curve for all defined thresholds indicated acceptable to excellent discrimination. The thresholds for achieving the PASS, defined at the 2-, 5-, and 10-year respectively, were as follows: mHHS: 77.5, 85.5, and 78.5; HOS-SSS: 82.7, 76.4, and 67.7; and iHOT12: 67.4, 76.9, and 62.9. The percentage of patients achieving the PASS increased from 2 to 10 years, with the highest percentage at 10 years. The threshold for achieving the SCB was defined as follows: mHHS: 95, 99, and 88; HOS-SSS: 97, 80.9, and 90.5; and iHOT12: 89.4, 94.1, and 82.5. The percentage of patients achieving the SCB increased from 2 to 10 years. The mean changes required to achieve the MCID were defined as follows: mHHS: 7, 7.1, and 7.4; HOS-SSS: 10.6, 10.7, and 11.2; and iHOT12: (9.6, 9.7, -). The MCID and the percentage of patients achieving the MCID remained constant over 2 to 10 years.

Conclusion:

Patients met the MCID, PASS, and SCB thresholds at high rates over 10 years. Based on the PASS and SCB thresholds, patient expectations for function evolved. Lower expectations at long-term follow-ups may result in a higher percentage of patients meeting certain thresholds, as evidenced in the mHHS, HOS-SSS, and iHOT12 in this cohort. Understanding the evolution of patient expectations may help interpret clinically relevant thresholds in future studies.

Keywords

femoroacetabular impingement syndrome hip arthroscopy minimal clinically important difference Patient Acceptable Symptom State patient expectations substantial clinical benefit

Hip arthroscopy has become an integral tool in the treatment of femoroacetabular impingement (FAI) syndrome and labral tears in the general population and has demonstrated favorable long-term outcomes.⁹ Patient-reported outcome (PRO) scores are heavily relied on in the literature to determine the patient’s functional status.^19,22 Multiple validated PRO scores are commonly used in the field of hip preservation.^1,7,14,28 Although initially designed for research purposes, PROs now play a crucial role in clinical practice.¹² To provide clinical correlation, several thresholds—including minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and substantial clinical benefit (SCB)—have been developed to consider patient satisfaction in correlation to functional status. The MCID and SCB thresholds have been developed within a functional outcome domain. The MCID is defined as the smallest change that is clinically meaningful and detectable to a patient, and the SCB is defined as the absolute threshold at which a patient has had major improvement, usually a calculated value that exceeds the PASS threshold.¹³ The PASS was developed within the satisfaction domain and is defined as the absolute threshold at which a patient’s outcome can be considered satisfactory.¹⁷

Previous studies have defined these thresholds for many PROs in hip preservation.^25,26,29 Many studies have cited these defined thresholds to add clinical correlation to their studies; however, often these defined thresholds are for different patient populations at different timepoints. Recent studies have suggested the time-dependent nature of these clinically meaningful thresholds, as well as being population-specific.²⁵ No analysis is available about how MCID, PASS, and SCB thresholds change over long-term follow-ups.

Given the paucity in the literature, the primary purpose of this study was to evaluate the time-dependent nature of clinically relevant thresholds and how it relates to the evolution of patient expectations by defining MCID, PASS, and SCB thresholds over the 2-year, 5-year, and 10-year timepoints for the modified Harris Hip Score (mHHS), Hip Outcome Score–Sports-Specific Subscale (HOS-SSS), and International Hip Outcome Tool (iHOT12). Second, we sought to evaluate how this evolution of patient expectations is associated with changes in rates of achievement of these clinically relevant thresholds. We hypothesized that as the MCID, PASS, and SCB change over time, the rates of achieving these thresholds would trend upward over the 2-, 5-, and 10-year follow-up timepoints. As patient expectations get more realistic over time, we hypothesized that the highest rates of achievement would be at long-term follow-ups.

Methods

Participation in the American Hip Institute Hip Preservation Registry

All patients included in this study participated in the American Hip Institute Hip Preservation Registry. Although this study presents a unique analysis, previous studies may have reported on some of the patients in this study. All data collection and reporting received institutional review board approval, and funding for this study was received from Arthrex (IIRR-01953).

Patient Selection and Matching Process

The patient selection and matching process are demonstrated in Figure 1. Data were retrospectively reviewed from a prospectively maintained database for patients who underwent primary hip arthroscopy labral repair, capsular repair/plication, and femoroplasty for FAI syndrome by the senior author (B.G.D.) between June 2008 and July 2021. Patients were considered eligible for the study if they had completed preoperative and follow-up data, defined as having complete PRO scores for the mHHS, HOS-SSS, and iHOT12 with anchor questions. Patients were excluded from the study if they had a lateral center edge angle (LCEA) of ≤18, a workers compensation claim, a labral reconstruction, a labral debridement, previous ipsilateral hip surgery, or a previous hip condition (ie, avascular necrosis, ankylosing spondylitis, Ehlers-Danlos syndrome, Legg-Calvé-Perthes disease, pigmented villonodular synovitis, or slipped capital femoral epiphysis). Patients who underwent a secondary arthroscopy, conversion to total hip arthroplasty, or did not answer the anchor questions were also excluded from the analysis. The iHOT12 and anchor questions were not added to our institution’s questionnaires until 2015, which is why there were 3 groups based on whether patients had the 2-, 5-, and/or 10-year data rather than 1 cohort with follow-ups at each timepoint of interest. This also means that no preoperative iHOT12 data were available for the 10-year follow-up period, limiting the ability to calculate the MCID.

Comparable groups were constructed through propensity score matching using a 1 to 1 to 1 match. Matching was performed in RStudio (R Version 4.3.2) utilizing the optimal algorithm. The propensity score was determined using a multiple logistic regression model that incorporated age at time of surgery, body mass index (BMI), sex, preoperative LCEA, preoperative alpha angle, postoperative alpha angle, iliopsoas fractional lengthening, and ligamentum teres debridement as covariates. The patients who did not match were excluded from the analysis as they were deemed noncomparable in the adjusted comparison.

Preoperative Evaluation and Surgical Indications

A detailed patient history, physical examination, and radiographic analysis were collected and evaluated by the senior author (B.G.D.) to determine whether a patient was a candidate for surgery. Patient preoperative characteristics were collected at the preoperative visit. Other characteristics recorded during the initial consultation and subsequent reevaluation visits included gait, range of motion, strength, points of tenderness, signs of FAI, and mechanical symptoms (ie, snapping, catching, and locking) from physical examinations. Supine and standing anteroposterior pelvis, Dunn 45°, and false-profile views were collected for radiographic analysis of acetabular and femoral morphology. Radiographic measurements, done by trained fellows in hip preservation under the guidance of the senior author (B.G.D.), included the LCEA, anterior center edge angle, alpha angle, Tonnis angle, and Tonnis grade. Magnetic resonance arthrography was also obtained on all patients before surgical indication to identify intra-articular pathology, such as labral tears or chondral damage. All patients underwent a minimum of 3 months of conservative treatment measures, such as physical therapy, medications, injections, and activity modification, before proceeding to surgery.

Surgical Technique

All arthroscopic surgeries were performed by the senior author (B.G.D.). Under general anesthesia, patients were placed in the modified supine position, and traction was applied to the hip. The anterolateral and mid-anterior portals were created, and an interportal capsulotomy was used to access the joint.¹⁸ Once in the joint, a systematic diagnostic arthroscopy was performed to assess the labrum, intra-articular cartilage, and ligamentum teres. Labral tears were classified using the Seldes classification system.¹⁵ Femoral-head chondral pathologies were noted, with the acetabular labrum articular disruption and Outerbridge classifications. Tear of the ligamentum teres was defined using the Domb and Villar classification.^2,4

Under fluoroscopic guidance, acetabuloplasty and femoral osteoplasty were performed to address pincer-type and cam-type morphologies, respectively. Labral tears were repaired through either a base refixation technique or a controlled-tension anatomic loop stitch with Knotless 1.8 Hip FiberTak Anchor or PEEK 3.0–mm Knotless Hip SutureTak Anchor (Arthrex, Inc.; N). Patients who had a presurgical history of painful, internal snapping hip syndrome received an iliopsoas fractional lengthening. Iliopsoas fractional lengthening was performed by cutting the iliopsoas tendon at the muscle-tendon junction.¹¹ Ligamentum teres tears were treated with debridement. Repair or plication of the interportal capsulotomy was performed at the end of each procedure.¹⁰

Rehabilitation Protocol

After surgery, all patients used crutches with a 20-pound weightbearing restriction and were placed in a hip brace (DonJoy VersaRom) locked at 90° of flexion and 0° of extension for 2 weeks. The patient’s operative leg was subjected to a continuous passive motion machine, which started the day after surgery, continuing for 4 weeks. All patients took part in supervised physical therapy sessions aimed at enhancing range of motion, strengthening the hip stabilizers, and strengthening core muscles. Prophylactic celecoxib and low-molecular-weight heparin, respectively, were administered for 4 weeks to prevent heterotopic ossification and thrombosis.

Functional Outcome Evaluation and Determining Thresholds

All patients included in this study completed questionnaires at their preoperative appointments and at 2-, 5-, or 10-year timepoints. Questionnaires were collected either in the clinic, via encrypted emails, or by telephone interviews. Preoperative questionnaires were completed within a month of surgery and were utilized to establish a baseline. At the 2-, 5-, and 10-year timepoints, anchor questions (“Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that the state of your right/left hip is satisfactory?” and “Since your hip arthroscopy how would you rate your overall physical ability?”) were collected in addition to PROs. The data were used to define MCID, PASS, and SCB thresholds for the mHHS, HOS-SSS, and iHOT12 at the 2-, 5-, and 10-year timepoints to quantify the clinical significance of meaningful outcome achievement. The MCID was calculated^17,24 using the distribution-based method, where the standard deviation of baseline scores is divided by 2. It is important to note that because the iHOT12 was not added until recently, preoperative data were not available to calculate the MCID at the 10-year timepoint.

The PASS and SCB thresholds were calculated using an anchor-based method. For the PASS, patients answered yes or no to the following anchor question: “Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that the state of your right/left hip is satisfactory?” Patients who answered yes were considered responders, and patients who answered no were considered nonresponders. For the SCB, patients answered “much improved,” “improved,” “slightly improved,” “much worse,” “worse,” “slightly worse,” or “no change” to the following anchor question: “Since your hip arthroscopy, how would you rate your overall physical ability?” Patients who answered “much improved” were considered responders, and patients who answered anything else were considered nonresponders. To calculate these thresholds, PROs at a specific timepoint were used to create a receiver operating characteristic (ROC) curve to discriminate and determine a value that qualitatively separated the 2 groups.

Statistical Analysis

An a priori power analysis was used to determine the sample size needed to achieve 80% power. A mean difference of 8 and a standard deviation of 20 determined that 100 cases were required for each study group. Statistical analyses were performed in Microsoft Excel with the RealStats Add-In Function, GraphPad, and RStudio (R Version 4.3.2). Descriptive statistics for categorical variables were evaluated using the chi-square and Fisher exact tests and reported as totals and percentages. Descriptive statistics for continuous variables were first assessed for equal variance and normality utilizing the F test and the Shapiro-Wilk test, respectively. A 2-tailed t test was used to assess normally distributed data sets with equal variance, and a nonparametric equivalent, such as the Wilcoxon signed-rank test, was utilized for data sets not distributed or with unequal variance. Continuous variables were reported as means, standard deviations, and ranges.

The ROC curve was generated utilizing RStudio (R Version 4.3.2). The ROC curve area under the curve (AUC) was reported as a measure of accuracy and was further used to determine discriminatory thresholds. This method has been used previously in the literature to determine the PASS.⁵ An AUC of 0.50 was equated with random assignment, an AUC between 0.70 and 0.80 was equated with acceptable discrimination, an AUC of >0.80 was equated with excellent discrimination, and an AUC of 1 was equated with perfect assignment.⁸

Results

Patient Characteristics

A total of 379 hips met the inclusion criteria at the 2-year timepoint, 325 hips at the 5-year timepoint, and 138 hips at the 10-year timepoint. The 3 groups were propensity-matched 1 to 1 to 1 based on incorporated age at the time of surgery, BMI, sex, preoperative LCEA, preoperative alpha angle, postoperative alpha angle, iliopsoas fractional lengthening, and ligamentum teres debridement. A total of 414 hips matched. There were 138 hips in the 10-year cohort, of which 73.9% were female, with a mean age of 28.3 ± 11.4, a mean BMI of 23.8 ± 4.6 kg/m², and an LCEA of 30.7 ± 6.1. There were 138 hips in the 5-year cohort, of which 73.9% were female, with a mean age of 29.9 ± 12.4, a mean BMI of 23.9 ± 4 kg/m², and an LCEA of 29.5 ± 5.5. There were 138 hips in the 2-year cohort, of which 73.2% were female, with a mean age of 27.9 ± 11.4, a mean BMI of 23.6 ± 4 kg/m², and an LCEA of 30.2 ± 5.7. All hips underwent similar arthroscopic procedures, as it was controlled for in the inclusion/exclusion criteria, as well as matching covariates.

MCID Calculations

Utilizing the distribution method, the mean changes required to achieve the MCID were as follows: mHHS: 7, 7.1, and 7.4; HOS-SSS: 10.6, 10.7, and 11.2; and iHOT12: (9.6, 9.7, - ). The MCID remained constant for the mHHS and HOS-SSS between the 2-, 5-, and 10-year timepoints, and the iHOT12 between the 2- and 5-year timepoints. For the mHHS, the MCID was achieved by 85.5%, 81.2%, and 83.3% of patients at the 2-, 5-, and 10-year timepoints, respectively (Figure 2). There was no significant difference in the percentage of patients achieving MCID for mHHS (P = .625). For the HOS-SSS, the MCID was achieved by 83.3%, 82.6%, and 79.7% of patients at the 2-, 5-, and 10-year timepoints, respectively (Figure 3). There was no significant difference in the percentage of patients achieving MCID for the HOS-SSS (P = .710). For the iHOT12, the MCID was met or exceeded by 88.4% and 92.8% of patients at the 2- and 5-year timepoints, respectively (Figure 4). There was no significant difference in the percentage of patients achieving MCID for the iHOT12 (P = .216).

ROC Analysis for the PASS and SCB

The thresholds for the PASS were calculated using the following anchor question: “Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that the state of your right/left hip is satisfactory?” In the 2-year group, 81.9% answered yes, indicating they were satisfied. In the 5-year group, 88.4% answered yes. In the 10-year group, 87% answered yes. The thresholds for achieving the PASS at the 2-, 5-, and 10-year timepoints were defined as follows: mHHS: 77.5, 85.5, and 78.5; HOS-SSS: 82.7, 76.4, and 67.7; and iHOT12: 76.2, 76.9, and 57.4. The respective AUC values for the PASS threshold at the 2-, 5-, and 10-year timepoint for the mHHS, HOS-SSS, and iHOT12 indicated excellent discrimination (AUC >0.8) (Tables 1 -3). PASS threshold values were highest at 5 years for the mHHS, HOS-SSS, and iHOT12 and significantly decreased from 5 to 10 years. For all PROs, the percentage of patients achieving PASS increased over the 2-, 5-, and 10-year timepoints (Figures 2 -4). For the mHHS and iHOT12, there was a statistically significant increase in the percentage of patients achieving the PASS from the 5- to 10-year timepoint (P < .05).

Table 1

ROC Analysis for the mHHS ^a

	Threshold Value	Sensitivity, %	Specificity, %	AUC (95% CI)	Patients Achieving Threshold, n (%)	Anchor Responder, n (%)
PASS
2 y	77.5	0.903	0.760	0.879	108 (78.3)	113 (81.9)
5 y	85.5	0.803	1	0.951	98 (71)	122 (88.4)
10 y	78.5	0.933	0.778	0.838	116 (84.1)	120 (87)
SCB
2 y	95	0.857	0.652	0.799	73 (52.9)	49 (35.5)
5 y	99	0.740	0.739	0.769	60 (43.5)	50 (36.2)
10 y	88	0.909	0.542	0.777	88 (63.8)	55 (39.9)

AUC, area under the curve; mHHS, modified Harris Hip Score; PASS, Patient Acceptable Symptom State; ROC, receiver operating characteristic; SCB, substantial clinical benefit.

Table 2

ROC Analysis for HOS-SSS ^a

	Threshold Value	Sensitivity, %	Specificity, %	AUC (95% CI)	Patients Achieving Threshold, n (%)	Anchor Responder, n (%)
PASS
2 y	82.7	0.761	0.840	0.856	90 (65.2)	113 (81.9)
5 y	76.4	0.820	1	0.932	100 (72.5)	122 (88.4)
10 y	67.7	0.858	0.778	0.821	107 (77.5)	120 (87)
SCB
2 y	97	0.755	0.798	0.800	55 (39.9)	49 (35.5)
5 y	80.9	0.920	0.477	0.728	92 (66.7)	50 (36.2)
10 y	90.5	0.709	0.687	0.731	65 (47.1)	55 (39.9)

AUC, area under the curve; HOS-SSS, Hip Outcome Score–Sports-Specific Subscale; PASS, Patient Acceptable Symptom State; ROC, receiver operating characteristic; SCB, substantial clinical benefit.

Table 3

ROC Analysis for the iHOT12 ^a

	Threshold Value	Sensitivity, %	Specificity, %	AUC (95% CI)	Patients Achieving Threshold, n (%)	Anchor Responder, n (%)
PASS
2 y	67.4	0.867	0.880	0.914	101 (73.2)	113 (81.9)
5 y	76.9	0.836	1	0.948	102 (73.9)	122 (88.4)
10 y	62.9	0.950	0.778	0.840	118 (85.5)	120 (87)
SCB
2 y	89.4	0.837	0.708	0.831	66 (47.8)	49 (35.5)
5 y	94.1	0.800	0.682	0.777	68 (49.3)	50 (36.2)
10 y	82.5	0.909	0.566	0.742	86 (62.3%)	55 (39.9%)

AUC, area under the curve; iHOT12, International Hip Outcome Tool; PASS, Patient Acceptable Symptom State; ROC, receiver operating characteristic; SCB, substantial clinical benefit.

The thresholds for the SCB were calculated using the following anchor question: “Since your hip arthroscopy, how would you rate your overall physical ability?” In the 2-year group, 35.5% marked “much improved.” In the 5-year group, 36.2% marked “much improved.” In the 10-year group, 39.9% marked “much improved.” The thresholds for achieving the SCB were as follows: mHHS: 95, 99, and 88; HOS-SSS: 97, 80.9, and 90.5; and iHOT12: 89.4, 94.1, and 82.5. The respective AUC values for the SCB threshold at the 2-, 5-, and 10-year timepoints for the mHHS, HOS-SSS, and iHOT12 indicated acceptable discrimination (AUC >0.7) (Tables 1 -3). Similar to the PASS thresholds, the SCB threshold for the mHHS and iHOT12 was highest at 5 years. The SCB threshold for the HOS-SSS was highest at the 2-year timepoint. For all PROs, the percentage of patients achieving the SCB increased from the 2- to 10-year timepoints (Figures 2 -4). For the mHHS and iHOT12, there was a statistically significant increase in the percentage of patients achieving the SCB from the 5- to 10-year timepoint (P < .05). For the HOS-SSS, there was a statistically significant increase in the percentage of patients achieving the SCB from the 2- to 5-year timepoint and a significant decrease in the percentage of patients achieving the SCB from 5- to 10-year timepoint (P < .05).

Discussion

In this study, we sought to define and evaluate the time-dependent nature of the clinically relevant thresholds (MCID, PASS, and SCB) for the mHHS, HOS-SSS, and iHOT12 at 2-year, 5-year, and 10-year timepoints after primary hip arthroscopy for FAI. We found that PASS thresholds for the mHHS and iHOT12 were highest at 5 years, with a significant decrease from 5 to 10 years, and PASS thresholds for the HOS-SSS were highest at 2 years, with a significant decrease from 2 to 10 years. Similarly, we found that SCB thresholds for the mHHS and iHOT12 were also highest at 5 years, with the iHOT12 significantly decreasing in the threshold value from 5 to 10 years. We also sought to evaluate how this evolution of patient expectations, shown by the change in threshold values over time, is associated with changes in the rate of achievement. The percentage of patients achieving the PASS and SCB increased from 2 to 10 years, with the highest percentage of achievement at 10 years for all thresholds except the SCB threshold for the HOS-SSS, which was highest at 5 years. Our findings suggest, as we had hypothesized, that patients’ expectations do change over time, leading to continued, and at times significantly increased, patient satisfaction.

Previous studies have also defined clinically relevant thresholds for commonly used hip preservation PROs at various timepoints for primary hip arthroscopy.^{3,6,19,21,25,26,31} The 2- and 5-year MCID, PASS, and SCB thresholds reported in the present study are similar to the values reported in other studies, validating the appropriateness of our analysis. Although similar, it is important to note that these thresholds are patient population specific, as thresholds can be impacted by modifiable factors, as pointed out in an editorial commentary by Sharp et al and a systematic review by Walsh et al.^30,32 A study by Maldonado et al²⁰ established and evaluated the PASS at the 2-year timepoint for patients who underwent revision hip arthroscopy. When comparing our thresholds for primary hip arthroscopy to those developed by Maldonado et al for revision hip arthroscopy, their thresholds at the 2-year time point are notably lower. For example, their PASS threshold for the HOS-SSS was 64.3; in comparison, we found the threshold to be 82.7. To minimize variability, it is important to use the threshold that correlates with the patient population and follow-up timepoint of interest if wanting to cite a previously defined threshold, which has not always been done.

Another aim of our study was to evaluate the time-dependent nature of these clinically meaningful thresholds. Similar to our study, Nwachukwu et al²⁵ evaluated the temporal nature of the MCID, PASS, and SCB for patients undergoing primary hip arthroscopy for FAI. This study found that values needed to achieve the MCID, SCB, and PASS for the mHHS, HOS-ADL, HOS-SS, and iHOT12 were highest at the 5-year timepoint, illustrating that thresholds are not only population-dependent but time-dependent. The results of the present study are in line with those of Nwachukwu et al at the 2-year and 5-year timepoints. Our study adds to the findings of Nwachukwu et al by adding long-term follow-up data. We found that the PASS threshold values decreased at the 10-year time point, suggesting, in general, patients required a lower postoperative PRO score to be satisfied with their surgical outcome.

Although a high percentage of patients in the present study met the defined thresholds, an even higher percentage of patients reported they were satisfied with the outcome of their surgery. This finding suggests that defined thresholds may underestimate the number of people satisfied with the outcome of their surgery. Many studies have looked at the causative agents that would leave patients satisfied even with lower functional scores, often related to age and lifestyle changes.^9,16 For instance, a study by Jimenez et al¹⁶ found that the decision about whether a high-level athlete would return to sports is not necessarily correlated with a patient’s outcome. The study discussed that many factors influence return to sports, including lifestyle modification and a loss of interest in the sport. Although these findings are for a specific population, they are in line with what we see in our study at the 10-year timepoint. These findings on patient satisfaction emphasize the importance of physicians collecting anchor questions, as statistical significance does not always correlate to be a clinically meaningful change.²³

While there is a growing body of literature evaluating the association of patient expectations and PROs, many questions remain unanswered. There is especially a need for more studies to evaluate the continuum of how patient expectations change over the long-term follow-up time frame. We attempt to answer some of these questions in our study; nonetheless, we urge caution in interpretation for the limitations outlined below.

Strengths

The present study aimed to fill the gap in the literature by investigating how patient expectations change from the short-term to long-term follow-up. Our study is one of the first to determine threshold values for patients undergoing primary hip arthroscopy for FAI from 2-, 5-, and 10-year timepoints for the mHHS, NAHS, iHOT12, and HOS-SSS. There are several strengths in the present study, further reinforcing the findings reported. The controlled confounding variables of the study hold significant importance. The inclusion of previously validated functional hip outcome scores for hip preservation surgery limits a potential ceiling effect and increases the generalizability of the results. Multiple clinical psychometric tools—including MCID, PASS, and SCB—were utilized to assess clinical importance. In addition, established methods commonly used in previous literature were used to calculate the MCID, PASS, and SCB.

Limitations

The present study is not without limitations. First, this study was a retrospective analysis; however, all data were collected prospectively as part of the institutional hip registry. Second, as with all other studies using anchor questions aimed at capturing a patient’s current condition in relation to their preoperative status, these questions are subject to recall bias, which may significantly impact the patient’s classification as a responder or nonresponder. Third, we only evaluated PROs and did not evaluate other important determinants of surgical outcomes, such as complications and reoperations. Fourth, because anchor questions were implemented more recently at our institution, there was a loss to follow-up of patients who did not answer the anchor questions, which may introduce selection bias. Finally, this study included patients operated on by a single, high-volume surgeon, which may limit the generalizability of these results.

Future Directions

The present study contributes to the growing body of literature on the evolution of patient expectations and satisfaction in hip arthroscopy over long-term follow-ups. More studies are needed to fully understand this continuum and how it evolves. Future studies should specifically investigate the subset of patients who report satisfaction but do not meet the threshold and the subset of patients who report being unsatisfied but meet the threshold, as well as predictors of achieving these thresholds. Furthering our understanding of this topic is important as insurance programs, such as Medicare and Medicaid Services, are implementing PROs into their composite quality score for institutions.²⁷ Although these policies are currently for joint replacement, it is important to note the trends of value-based care, as similar policies may be implemented for hip arthroscopy in the future.

Conclusion

Patients met the MCID, PASS, and SCB at high rates over 10 years. Based on thresholds for the PASS and SCB, patient expectations for function evolved. Lower expectations at long-term follow-ups may result in a higher percentage of patients meeting certain thresholds, as evidenced in the mHHS, HOS-SSS, and iHOT12 in this cohort. Understanding the evolution of patient expectations may help interpret clinometric thresholds in future studies.

Footnotes

Submitted June 12, 2024; accepted March 31, 2025.

One or more of the authors has declared the following potential conflict of interest or source of funding: B.G.D. has had ownership interests in the American Hip Institute and affiliates, North Shore Surgical Suites, and Munster Specialty Surgery Center; research support from Arthrex, Stryker, Smith & Nephew, and Ossur; consulting fees from Arthrex, Medacta, Stryker, and SI-Bone Inc; has received educational support from Arthrex, Stryker; speaking fees from Arthrex; travel and lodging from Arthrex and Stryker; food and beverage from Arthrex, DJO Global, Medacta, Stryker, Zimmer Biomet, DePuy Synthes Sales, Medtronic, Trice Medical, Medwest Associates, SI-Bone Inc, Xiros Inc, Intellijoint Surgical Inc, Electronic Waveform Lab Inc; royalties from Arthrex, DJO Global, Medacta, Orthomerica; patents with Arthrex, Orthomerica, and DJO Global. B.G.D. is Director of Hip Preservation at St. Alexius Medical Center and a board member for the American Hip Institute Research Foundation, Arthroscopy Association of North America Learning Center Committee, the Journal of Hip Preservation Surgery, Journal of Arthroscopy, AOSSM Research Committee, and ISHA – The Hip Preservation Society Executive Board. The American Hip Institute Research Foundation (American Orthopedic Foundation) funds research and is where the study was performed. R.Q-J. reports receiving travel reimbursement from Arthrex and Zimmer Biomet. A.H.K-R. reports receiving travel reimbursement from Arthrex and Zimmer Biomet. T.R.M. reports receiving travel reimbursement from Arthrex, Smith & Nephew, and Stryker. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto. This study was performed in accordance with the ethical standards in the 1964 Declaration of Helsinki. This study was carried out in accordance with the relevant regulations of the United States Health Insurance Portability and Accountability Act. Details that might disclose the identity of the patients under study have been omitted. This study was approved by an Institutional Review Board (IRB ID: 5276).

ORCID iDs

Elizabeth G. Walsh

Tyler R. McCarroll

Benjamin D. Kuhns

Ady H. Kahana-Rojkind

Roger Quesada-Jimenez

Benjamin G. Domb

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