Hip‐Specific Patient‐Reported Outcomes Strongly Correlate With Pain and Physical Function Metrics but not Mental Health Before and After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

Abstract

Purpose

To assess the relationships between hip‐specific patient‐reported outcomes (PROs) metrics and general health and pain measures before and after hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

Methods

This was a retrospective study of patients undergoing hip arthroscopy for FAIS at a single institution from 2014 to 2025. PRO scores, including hip‐specific scores of modified Harris hip score (mHHS) and Hip Disability and Osteoarthritis Outcome Score (HOOS), as well as general health scores including 12‐Item Short Form Survey (SF‐12) physical and mental components and visual analog scale pain, were collected. Spearman correlation coefficients were calculated to assess the relationship between hip‐specific outcome scores and quality of life metrics across multiple pre‐ and postoperative time points.

Results

Six hundred sixty‐eight patients (53.9% female) average age 34.3 years, body mass index 24.6, and mean follow‐up 20.1 ± 14.0 months (range 3‐60) were included. Both hip‐specific PRO tools (HOOS and mHHS) showed at least strong‐moderate, but mostly strong, correlations with both the visual analog scale pain scale and SF‐12 physical component score preoperatively and at all time points postoperatively (Spearman's ρ range: −0.64 to −0.81, P < .01). The HOOS Total and mHHS had only poor or nonsignificant correlations with the SF‐12 mental component score. At 1‐, 2‐, and 5‐year follow‐up after surgery, 75.3% to 81.6% of patients achieved minimal clinically important difference (MCID) for HOOS Total and 63.3% to 65.9% for mHHS. Furthermore, 61.4% to 73.5% of patients achieved MCID for SF‐12 physical component score, whereas only 33.2% to 44.9% achieved MCID for SF‐12 mental component score.

Conclusions

Hip‐specific PRO scores have significant, strong correlations with both pain and physical function metrics before and after hip arthroscopy for FAIS. However, there was little to no correlation between hip‐specific PROs and mental health metrics in this cohort.

Level of Evidence

Level IV, retrospective case series.

Femoroacetabular impingement syndrome (FAIS) is an increasingly recognized cause of hip pain and dysfunction in young and middle‐aged patients. ¹ , ² Initial management of FAIS is typically conservative with multimodal pain control, activity modification, and physical therapy. ³ However, as symptoms progress and nonoperative measures are no longer sufficient, operative management with hip arthroscopy, including osteoplasty and labral repair, is typically indicated. ⁴ , ⁵ Given the increased recognition of FAIS and thus increased rates of hip arthroscopy, there has been an increased interest in quantifying patient‐reported outcomes (PROs). ⁶ , ⁷ A number of hip‐specific PRO measures are commonly used, with the most common being the modified Harris hip score (mHHS) and Hip Disability and Osteoarthritis Outcome Score (HOOS). ⁸ , ⁹ Previous studies have shown strong relationships between hip‐specific PRO scores. ¹⁰ , ¹¹

There has been a growing interest in examining patient function postoperatively in more than just hip‐specific outcomes by looking at global pain scores and general health/quality of life metrics. ¹² , ¹³ Two common metrics that have been used are the visual analog scale (VAS) for pain as well as the 12‐Item Short Form Survey (SF‐12) for general health status. ¹⁴ , ¹⁵ However, there has been little research into the relationship between SF‐12 and VAS scores with the PRO scores mHHS and HOOS. ¹⁶ , ¹⁷ In the age of comprehensive patient assessment and care, evaluating the patient as a whole as opposed to focusing solely on limb‐specific outcomes is particularly salient.

The purpose of this study was to assess the relationships between hip‐specific PROs metrics and general health and pain measures before and after hip arthroscopy for FAIS. We hypothesized that the hip‐specific outcomes, mHHS and HOOS, would both have strong, statistically significant, and clinically meaningful relationships with the general health metrics and pain scores.

METHODS

Study Design

This was a retrospective study of patients undergoing hip arthroscopy for FAIS from 2014 to 2025, analyzing the relationships between hip‐specific PRO scores and general health metrics. Inclusion criteria included a diagnosis of FAIS, as determined by both clinical and radiographic measures, as well as preoperative and postoperative scores on the HOOS, mHHS, VAS, and SF‐12. Patients undergoing revision surgery, open surgery, or those that showed radiographic evidence of osteoarthritis (Tonnis grade ≥ 1) or hip dysplasia (lateral center‐edge angle < 20) were excluded from the study.

All procedures were performed at the ambulatory surgery center for a large academic institution by one of two fellowship‐trained sports orthopaedic surgeons with a subspecialty of hip pathology and hip arthroscopy (A.L.Z., S.E.W.). The standard mid‐anterior and anterior lateral portals were created to perform labral repair and osteoplasty via acetabuloplasty or femoroplasty, as necessary, depending on the presence of Cam and Pincer lesions. Interportal and periportal capsulotomy techniques were used for capsule management based on surgeon preference, with capsule closure performed on all interportal capsulotomies. Patients postoperatively were made foot‐flat weight‐bearing with crutches for the first 2 weeks before advancement of weight‐bearing, with return to running at 3 months after surgery and return to sports at 6 months after surgery. This study was approved by our Institutional Review Board (24‐42503).

PRO and Quality of Life Metrics

The HOOS is a 40‐item metric, comprising five subscales: activities, symptoms, function in daily living, function in sport/recreation, quality of life, and pain. ¹⁸ To calculate the total score, sub‐scales are calculated, averaged, and summed for a total score out of 100. The mHHS is another commonly used hip‐specific PRO score that measures pain and function on a scale from 0 to 100. ¹⁹ The VAS score is a pain scale from 0 to 10 frequently used throughout hospital settings to evaluate the global pain of patients. ²⁰ Finally, the SF‐12 is a general health measure that assesses a patient's global functioning and disability, split into a physical component score (PCS) and a mental component score (MCS). ²¹ For the purposes of this study, the HOOS Total score was used rather than the individual subscales to reduce multiple comparisons and facilitate comparisons across outcome instruments. Metrics were collected preoperatively and then at 3 months, 6 months, 1 year, 2 years, and 5 years postoperatively. As all analyses were performed separately for each time point as its own cohort to assess for time‐specific metric correlations, rather than longitudinally, patients were included if they had hip‐specific PRO and quality of life data available at that specific time point. The minimum postoperative follow‐up was 3 months, when the first set of PRO and quality of life metric data became available, to maximize the number of time points for investigating temporal changes in all analyses across this study.

Statistical Analysis

Descriptive statistics were used to describe the demographics of the final cohort and the scores for PRO and general health metrics. The minimal clinically important difference (MCID) for each tool and postoperative time point beyond the early rehabilitation stage (>6 months) was calculated as 0.5 times the standard deviation of the preoperative‐to‐postoperative score change, as previously described. ²² , ²³ Spearman correlations were used to determine the correlation between each hip‐specific PRO tool, mHHS and HOOS, and both quality of life metrics, SF‐12 and VAS. Correlations were calculated separately across scores collected at preoperative and 3‐month, 6‐month, 1‐year, 2‐year, and 5‐year postoperative time points. The strength of correlations was categorized as previously described: strong (ρ ≥ 0.7), strong‐moderate (ρ = 0.61‐0.69), moderate (ρ = 0.40‐0.60), moderate‐poor (ρ = 0.31‐0.39), and poor (ρ ≤ 0.30). ²⁴ Statistical significance was considered at P < .05. All analyses were performed using Stata 19.0 (StataCorp LLC).

RESULTS

A total of 668 patients were included in this study (Figure 1). Postoperative follow‐up duration was categorized by the maximum follow‐up achieved for each patient, with 668 patients (100%) followed to 3 months, 617 (92.4%) to 6 months, 511 (76.5%) to 1 year, 388 (58.1%) to 2 years, and 51 (7.6%) to 5 years. The mean follow‐up duration was 20.1 ± 14.0 (range: 3‐60, 95% CI: 19.0‐21.1). The average age was 34.3 ± 12.0 years (range: 13‐65, 95% CI: 33.4‐35.2), body mass index was 24.6 ± 4.0 (range: 17.0‐39.4, 95% CI: 24.3‐24.9), and most patients were female (53.9%) and White (77.8%) (Table 1). Across all patients who completed the preoperative hip‐specific PROs (N = 584 responses), HOOS Total had a mean score of 57.0 ± 18.2 (CI: 55.5‐58.5), and mHHS had a mean score of 62.0 ± 16.3 (95% CI: 60.6‐63.3) (Table 2). At the 5‐year postoperative mark for hip‐specific PROs (N = 51 responses), HOOS Total had a mean score of 85.9 ± 16.5 (95% CI: 81.3‐90.6) and mHHS of 81.8 ± 12.7 (95% CI: 78.2‐85.3). For quality of life metrics, VAS had a preoperative mean score of 4.2 ± 2.5 (95% CI: 4.0‐4.4) (N = 584 responses), SF‐12 PCS of 42.3 ± 8.6 (95% CI: 41.6‐43.0), and SF‐12 MCS of 47.0 ± 11.5 (95%CI: 46.1‐47.9). Five‐year postoperative averages were 1.3 ± 2.1 (95% CI: 0.7‐1.0) for VAS (N = 51 responses), 49.7 ± 8.9 (CI: 47.2‐52.2) for SF‐12 PCS, and 49.2 ± 9.7, (95%CI: 46.4‐51.9) for SF‐12 MCS.

FIGURE 1.

Patient flowchart.

TABLE 1.

Cohort Characteristics (N = 668)

Age, years (mean (SD), range (95% CI))	34.3 (12.0), 13.0‐65.0 (33.4‐35.2)
Sex
Female	360 (53.9%)
Male	308 (46.1%)
Race/ethnicity
White	520 (77.8%)
Asian	35 (5.2%)
Latinx	40 (6.0%)
Black or African American	11 (1.7%)
Other	62 (9.3%)
BMI (mean (SD), range (95% CI))	24.6 (4.0), 17.0‐39.4 (24.3‐24.9)
Follow‐up duration, months (mean (SD), range (95% CI))	20.1 (14.0), 3‐60 (19.0‐21.1)

BMI, body mass index; CI, confidence intervals; SD, standard deviation.

TABLE 2.

PRO and Quality of Life Metric Scores

HOOS total
Combined	N = 2274 Responses	73.8 ± 20.5, (73.0‐74.7)
Pre‐Op	N = 584 Responses	57.0 ± 18.2, (55.5‐58.5)
3 months	N = 435 Responses	76.1 ± 16.2, (74.6‐77.7)
6 months	N = 441 Responses	80.5 ± 17.3, (78.9‐82.2)
1 year	N = 376 Responses	80.1 ± 18.6, (78.2‐82.0)
2 years	N = 387 Responses	81.3 ± 19.5, (79.3‐83.2)
5 years	N = 51 Responses	85.9 ± 16.5, (81.3‐90.6)
mHHS total
Combined	N = 2274 Responses	73.6 ± 16.4, (72.9‐74.3)
Pre‐Op	N = 584 Responses	62.0 ± 16.3, (60.6‐63.3)
3 months	N = 435 Responses	75.1 ± 14.5, (73.8‐76.5)
6 months	N = 441 Responses	78.5 ± 13.6, (77.3‐79.8)
1 year	N = 376 Responses	77.9 ± 14.1, (76.5‐79.3)
2 years	N = 387 Responses	78.6 ± 15.4, (77.0‐80.1)
5 years	N = 51 Responses	81.8 ± 12.7, (78.2‐85.3)
VAS total
Combined	N = 2373 Responses	2.4 ± 2.4, (2.3‐2.5)
Pre‐Op	N = 584 Responses	4.2 ± 2.5, (4.0‐4.4)
3 months	N = 434 Responses	2.0 ± 1.9, (1.8‐2.1)
6 months	N = 441 Responses	1.7 ± 1.9, (1.5‐1.9)
1 year	N = 376 Responses	1.9 ± 2.1, (1.6‐2.1)
2 years	N = 387 Responses	1.9 ± 2.3, (1.6‐2.1)
5 years	N = 51 Responses	1.3 ± 2.1, (0.7‐1.9)
SF‐12 PCS
Combined	N = 2274 Responses	46.8 ± 9.1, (46.4‐47.2)
Pre‐Op	N = 584 Responses	42.3 ± 8.6, (41.6‐43.0)
3 months	N = 435 Responses	45.9 ± 8.4, (45.2‐46.7)
6 months	N = 441 Responses	48.7 ± 8.4, (48.0‐49.5)
1 year	N = 376 Responses	49.3 ± 8.6, (48.4‐50.2)
2 years	N = 387 Responses	49.6 ± 8.9, (48.6‐50.5)
5 years	N = 51 Responses	49.7 ± 8.9, (47.2‐52.2)
SF‐12 MCS
Combined	N = 2274 Responses	48.3 ± 10.5, (47.8‐48.7)
Pre‐Op	N = 584 Responses	47.0 ± 11.5, (46.1‐47.9)
3 months	N = 435 Responses	48.4 ± 10.2, (47.4‐49.4)
6 months	N = 441 Responses	49.4 ± 9.9, (48.5‐50.4)
1 year	N = 376 Responses	48.6 ± 9.9, (47.6‐49.6)
2 years	N = 387 Responses	48.3 ± 10.3, (47.3‐49.3)
5 years	N = 51 Responses	49.2 ± 9.7, (46.4‐51.9)

Note: Data are presented as mean ± SD, (95% CI).

CI, confidence intervals; HOOS, Hip Disability and Osteoarthritis Outcome Score; MCS, mental component score; mHHS, modified Harris hip score; PCS, physical component score; Pre‐OP, pre‐operative; PRO, patient‐reported outcome; SD, standard deviation; SF‐12: 12‐Item Short Form Survey, VAS, visual analog scale.

After the early rehabilitation period (>6 months), cohort‐specific MCID thresholds showed improvement across hip‐specific, physical function, and pain‐related outcomes, but not mental‐health related metrics. At 1, 2, and 5 years postoperatively, 75.3% to 81.6% of patients achieved MCID for HOOS Total and 63.3% to 65.9% achieved MCID for mHHS, whereas 59.1% to 67.3% met MCID thresholds for VAS pain (Table 3). At 2 and 5 years postoperatively, 53.4% to 73.5% of patients met the MCID thresholds for SF‐12 PCS, whereas only 28.5% to 44.9% met those for SF‐12 MCS.

TABLE 3.

Full Cohort MCID Across Nonearly Rehab Postoperative Time Points

	MCID Threshold	Percent Attained
1 year
HOOS total	9.7	75.3
mHHS total	8.1	65.9
VAS total	1.3	59.1
SF‐12 PCS	5.3	61.4
SF‐12 MCS	5.3	33.2
2 years
HOOS total	10.4	74.8
mHHS total	9.3	63.3
VAS total	1.4	60.8
SF‐12 PCS	5.4	53.4
SF‐12 MCS	5.8	28.5
5 years
HOOS total	10.8	81.6
mHHS total	9.7	65.3
VAS total	1.4	67.3
SF‐12 PCS	4.7	73.5
SF‐12 MCS	6.1	44.9

HOOS, Hip Disability and Osteoarthritis Outcome Score; MCID, minimal clinically important difference; MCS, mental component score; mHHS, modified Harris hip score; PCS, physical component score; SF‐12, 12‐Item Short Form Survey; VAS, visual analog scale.

There were mostly strong and at least strong‐moderate correlations between hip‐specific PRO tools with both the VAS pain scale and SF‐12 PCS preoperatively and at all time points postoperatively, with statistical significance shown throughout (Table 4). The strength of correlations was categorized as previously described: strong (ρ ≥ 0.7), strong‐moderate (ρ = 0.61‐0.69), moderate (ρ = 0.40‐0.60), moderate‐poor (ρ = 0.31‐0.39), and poor (ρ ≤ 0.30). Preoperatively, HOOS had a rho value of −0.64 with VAS and a value of 0.43 with SF‐12 PCS, whereas mHHS had a rho value of −0.64 with VAS and 0.46 with SF‐12 PCS, with all values showing statistical significance. Likewise, at 2‐year postoperative follow‐up, HOOS showed a rho value of −0.81 with VAS and 0.70 with SF‐12 PCS, whereas mHHS showed values of −0.79 with VAS and 0.72 with SF‐12 PCS, with all values showing statistical significance. VAS showed strong‐moderate associations with hip‐specific PRO scores preoperatively but strong associations postoperatively. Similarly, SF‐12 PCS showed moderate associations with hip‐specific PRO scores preoperatively which strengthened to strong‐moderate or strong postoperatively. Meanwhile, there were only poor correlations between these hip‐specific PRO metrics and the SF‐12 MCS across all time points. For example, preoperatively SF‐12 MCS had a rho value of 0.24 with HOOS and 0.18 with mHHS, and likewise showed rho values of 0.34 with HOOS and 0.30 with mHHS at 2‐year postoperative follow‐up. This poor correlation between hip‐specific PRO scores and SF‐12 MCS scores showed statistical significance at all time points until 5‐year postoperative follow‐up (Table 4). There were no differences in correlations across PRO's between male and female patients.

TABLE 4.

Correlations Between PRO and Quality of Life Metrics

	VAS Total	SF‐12 PCS	SF‐12 MCS
Pre‐Op
HOOS total	−0.64 (<0.01)	0.43 (<0.01)	0.24 (<0.01)
mHHS total	−0.64 (<0.01)	0.46 (<0.01)	0.18 (<0.01)
3 months
HOOS total	−0.70 (<0.01)	0.63 (<0.01)	0.39 (<0.01)
mHHS total	−0.70 (<0.01)	0.62 (<0.01)	0.28 (<0.01)
6 months
HOOS total	−0.75 (<0.01)	0.66 (<0.01)	0.40 (<0.01)
mHHS total	−0.73 (<0.01)	0.64 (<0.01)	0.35 (<0.01)
1 year
HOOS total	−0.77 (<0.01)	0.71 (<0.01)	0.37 (<0.01)
mHHS total	−0.73 (<0.01)	0.65 (<0.01)	0.30 (<0.01)
2 years
HOOS total	−0.81 (<0.01)	0.70 (<0.01)	0.34 (<0.01)
mHHS total	−0.79 (<0.01)	0.72 (<0.01)	0.30 (<0.01)
5 years
HOOS total	−0.75 (<0.01)	0.60 (<0.01)	0.07 (0.60)
mHHS total	−0.74 (<0.01)	0.42 (<0.01)	−0.05 (0.72)

Note: Data are presented as Spearman's rho (P value): strong (ρ ≥ 0.7), strong‐moderate (ρ = 0.61‐0.69), moderate (ρ = 0.40‐0.60), moderate‐poor (ρ = 0.31‐0.39), and poor (ρ ≤ 0.30). The bold values are indicate statistical signifiance.

HOOS, Hip Disability and Osteoarthritis Outcome Score; MCS, mental component score; mHHS, modified Harris hip score; PCS, physical component score; Pre‐Opr, pre‐operative; PRO, patient‐reported outcome; SF‐12, 12‐Item Short Form Survey; VAS, visual analog scale.

DISCUSSION

In this study, we found a correlation between hip‐specific PRO measures with both physical function and global pain scores. However, there did not seem to be a relationship between hip‐specific PROs and mental health outcomes in this cohort.

The overall strong correlations between improved mHHS and HOOS scores with both improved SF‐12 PCS and decreased VAS pain scores highlight that pain and function are intimately related in patients with FAIS. Furthermore, this relationship increased from moderately strong preoperatively to very strong postoperatively, building on previous studies suggesting that surgical intervention may create a more predictable function‐pain relationship by targeting the underlying anatomic pathology. ²⁵ , ²⁶ However, the implication that either function or pain PROs are interchangeable with hip‐specific tools and equally valuable metrics of hip‐specific disability is not supported fully by the data. Notably, although correlations between these measures were strong, the correlation coefficients consistently fell short of complete concordance, indicating that physical function and pain metrics, along with hip‐specific PROs, capture overlapping yet distinct constructs of hip‐related disability. This distinction is supported by studies showing only moderate correlations between changes in VAS and common hip PROs after hip arthroscopy, ²⁷ as well as differential agreement among hip outcome instruments when compared with multidomain tools, showing that pain and function cannot be used interchangeably to fully characterize hip disability. ²⁸ Thus, potentially highlighting the need for continued use of both pain and hip‐specific function metrics after hip arthroscopy surgery.

Although previous literature has shown significant improvements in patient mental health after hip arthroscopy, ²⁹ we found only weak correlations between hip‐specific outcome tools and mental health PROs and a limited number of patients achieving MCID for SF‐12 MCS postoperatively. Gruskay et al. reported that 84% of patients achieved improved mental health postoperatively following hip arthroscopy for FAIS. ³⁰ Patients with elevated depressive symptoms have also been found to experience significant reductions in symptom burden after hip arthroscopy. ¹⁶ In contrast, our cohort did not exhibit a strong association between mental health scores and hip‐specific PROs, nor did it show significant postoperative SF‐12 MCS improvement. This finding likely reflected a ceiling effect because of patient selection, as most of our patients had normal preoperative mental health scores which may be correlated with patient selection in which the surgeons may defer surgical treatment in patients who are in a poor mental health state. As mental health improvements postsurgery appear most pronounced in patients with low baseline scores, it is likely that our cohort had a more limited capacity for measurable improvement.

Our study showed a high rate of patients attaining at least the MCID with regard to hip‐specific PRO scores, general pain, and physical health metrics, whereas a significantly lower percentage of patients showed clinically significant improvement in mental health. Previous literature has shown similar trends. For example, in a 2021 retrospective case series of 300 patients undergoing arthroscopic treatment of FAI, Hartwell et al. showed that 66% of patients achieved MCID for mHHS, 63% for VAS, between 60% to 80% for HOOS sub scores, and 68% for SF‐12 PCS, whereas only 35% achieved MCID for SF‐12 MCS. ³¹ Similarly, in a prospective study on 176 patients undergoing hip arthroscopy for FAI between 2014 and 2021, Spencer et al. showed that most patients in their cohort achieved the MCID for HOOS subscale scores, ranging from 57% to 76% of the cohort population. ³² Such findings highlight the overall efficacy of hip arthroscopy for FAIS to improve hip‐specific symptoms as well as overall pain and physical health. However, patients must be cautioned preoperatively on the more limited benefit on mental health.

Limitations

This study has several limitations. First, there was a limited sample size and fewer metric responses at later postoperative time points. We included patients with a minimum postoperative follow‐up period of 3 months to analyze the correlation between surveys early in the recovery period. The follow‐up duration varied among patients, and analyses were performed at discrete perioperative time points rather than being performed longitudinally. Additionally, we used the HOOS Total score rather than individual HOOS subscales, which may have limited the detection of domain‐specific differences. Further, this cohort lacked Patient Acceptable Symptom State and Substantial Clinical Benefit metrics for consideration of clinically meaningful improvements. Finally, surgeries were performed at a high‐volume academic institute and results may not be generalizable across different practice settings.

CONCLUSIONS

Hip‐specific PRO scores have significant, strong correlations with both pain and physical function metrics before and after hip arthroscopy for FAIS. However, there was little to no correlation between hip‐specific PROs and mental health metrics in this cohort.

DISCLOSURES

The authors (W.B.D., A.L.Z.) declare the following financial interests/personal relationships which may be considered as potential competing interests: W.B.D. reports financial support was provided by Foundation for Orthopedic Research and Education. A.L.Z. reports a relationship with Stryker that includes consulting or advisory; reports a relationship with CONMED that includes consulting or advisory; reports a relationship with DePuy Synthes Mitek Sports Medicine that includes consulting or advisory. The other authors (L.S., H.S., Z.B., S.E.W.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.