Comparing 2-Year Outcomes between Hip Arthroscopy and Periacetabular Osteotomy for Acetabular Dysplasia With Femoroacetabular Impingement Syndrome vs. Hip Arthroscopy Alone for Femoroacetabular Impingement Syndrome Without Dysplasia

Abstract

Background:

Hip arthroscopy for femoroacetabular impingement syndrome (FAIS) yields excellent clinical outcomes. However, untreated concomitant acetabular dysplasia is associated with higher failure rates after arthroscopy. A combined approach of hip arthroscopy and periacetabular osteotomy (PAO) has shown promising results, but it remains unclear whether outcomes are equivalent to those of arthroscopy alone for FAIS without dysplasia.

Purpose/Hypothesis:

The primary purpose of this study was to compare 2-year patient-reported outcome (PROs) between patients with FAIS and acetabular dysplasia treated with staged hip arthroscopy and PAO and nondysplastic patients with FAIS treated with hip arthroscopy alone. The secondary purpose was to identify independent predictors of PROs at 2 years postoperatively. It was hypothesized that patients with FAIS and acetabular dysplasia treated with arthroscopy and PAO would demonstrate similar 2-year PROs compared with nondysplastic FAIS patients treated with arthroscopy alone.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 147 patients who underwent hip arthroscopy for FAIS were identified, including 23 patients in the dysplastic group and 124 in the control group. PROs were assessed at 2 years using Mental Health Inventory (MHI-5), 12-item international Hip Outcome Tool (iHOT-12), Physical Function Short Form of the Hip Disability and Osteoarthritis Outcome Score (HOOS-PS), University of California Los Angeles (UCLA) Activity Scale, Adult Single Item Measure (SIM) of Physical Activity, Patient Acceptable Symptom State (PASS) single item, and repeat surgery. Multivariate analyses adjusted for baseline demographics, preoperative superior joint space width, prior corticosteroid injection, and mental health status.

Results:

The dysplastic group was younger (mean age, 27.9 ± 8.7 years) and predominantly female (95.7%) compared with the control group (36.3 ± 12.8 years; 80.6% female) (age, P = .003; sex, P = .046, respectively). No differences were observed in 2-year iHOT-12 scores (67.20 vs 62.05; P = .45, respectively) or PASS achievement (69.56% vs 54.84; P = .18). On multivariate analysis, dysplasia was not an independent predictor of iHOT-12 score, PASS, or unplanned additional surgery. Preoperative joint space width was a significant predictor of revision surgery (adjusted odds ratio, 4.17; 95% CI, 1.49-11.1; P = .006).

Conclusion:

The treatment of FAIS with concomitant acetabular dysplasia with hip arthroscopy and PAO has similar 2-year PROs to patients with FAIS without dysplasia treated with arthroscopy alone.

Keywords

hip arthroscopy hip dysplasia femoroacetabular impingement periacetabular osteotomy

Femoroacetabular impingement (FAI) syndrome (FAIS) and acetabular dysplasia are both common pathologies associated with hip pain, and both predispose affected patients to the development of osteoarthritis (OA).^{5,12,13,16,18,43} In patients with FAIS alone, arthroscopic femoroacetabular osteoplasty (FAO) has excellent reported outcomes.²⁷ However, the presence of concomitant hip dysplasia is a poor prognostic indicator for the success of arthroscopic FAO alone.^1,24,36,44

In order to correct the bony acetabular deficiency that is seen in hip dysplasia, a periacetabular osteotomy (PAO) is often utilized, leading to improvement in pain in addition to delaying the development of OA.^46,48 These technically demanding procedures reorient the native shallow acetabulum to improve the overall coverage of the femoral head and therefore decrease shear forces along the acetabular rim.^19,41 Insufficient correction may lead to recurrence of preoperative symptoms, while overcorrection can result in anterior impingement caused by abutment of the femoral head-neck junction on the anterior rim of the overcorrected acetabulum.^19,41 Even if the proper degree of correction is achieved, the possibility of iatrogenic FAIS has been reported, especially with hip flexion and internal rotation.³² The rate of iatrogenic FAIS is increased in patients with preexisting cam-type impingement, defined as an aspherical head-neck junction, often referred to as a pistol grip or postslip deformity.¹⁷ Additionally, in patients with acetabular dysplasia, the anterosuperior acetabular rim deficiency may result in a prominent anterior inferior iliac spine (AIIS) that is positioned closer to the acetabular rim. The reorientation of the acetabular rim in the presence of a low-lying AIIS can result in a decreased range of motion in hip flexion due to subspinous impingement of the AIIS on the femoral head-neck junction. Additionally, the literature reports the incidence of symptomatic labral tears in dysplastic hips treated with PAO as ranging from 60% to 98%.²⁸

A combined approach of hip arthroscopy in conjunction with PAO, either staged or concomitantly performed, has been utilized in order to address these intra-articular concerns.^14,21,26,28 At this institution, patients are treated with a staged approach. The patients first undergo hip arthroscopy with acetabuloplasty, femoroplasty, labral repair, subspinous decompression with partial AIIS resection, and capsular plication/repair, all as indicated, approximately 3 weeks prior to proceeding with PAO. This allows for the visualization and surgical correction of intra-articular pathology, such as labral tears and chondral lesions, prior to proceeding with PAO.^11,38,45 A small single-center, single-surgeon (J.S.E.) retrospective case-control study examined outcomes in patients with acetabular dysplasia, with versus without concomitant cam-type impingement, following PAO, with additional FAO in the patients with cam-type impingement. Their examination of 85 hips showed no difference in radiographic results or PROs between the 2 groups postoperatively.³⁰ Additionally, many studies report worse outcomes in patients with FAIS and dysplasia treated with arthroscopy alone.^1,24,36,44 In examining the literature, there is a paucity of studies investigating how outcomes of patients with hip dysplasia who undergo PAO and FAO compare with those of patients without dysplasia who solely undergo FAO.

The primary purpose of this study was to compare 2-year patient-reported outcomes (PROs) between patients with FAIS and acetabular dysplasia who underwent staged hip arthroscopy and PAO and nondysplastic patients with FAIS who underwent hip arthroscopy alone. The secondary purpose was to identify independent predictors of PROs at 2 years postoperatively. We hypothesized that patients with FAIS and acetabular dysplasia treated with staged hip arthroscopy and PAO would demonstrate similar 2-year PROs compared with nondysplastic patients with FAIS treated with hip arthroscopy alone.

Methods

Patient Selection

After institutional review board approval was achieved from Indiana University School of Medicine, this study began enrolling patients who underwent hip arthroscopy for FAIS by the single surgeon between January 2021 and April 2023 (Figure 1). Inclusion criteria were (1) diagnosis of FAIS, (2) age between 14 and 65 years, (3) completion of 2-year postoperative outcomes survey, and (4) complete records available, including perioperative examinations and surgical records. FAIS was considered present when radiographic features of cam (alpha angle >55°) ± pincer morphology (lateral center-edge angle [LCEA] or anterior center-edge angle [ACEA] >40° or crossover sign) were accompanied by patient-reported symptoms consistent with hip impingement (eg, groin pain, pain with hip flexion or rotation, and mechanical symptoms). Exclusion criteria were (1) age <14 or >65 years old, (2) Tönnis grade 2 to 3 (moderate or severe) OA or minimum superior joint space width <2.0 mm, (3) hip arthroscopy for a diagnosis other than FAIS, (4) lack of response or incomplete response to postoperative outcomes survey, (5) diagnosis of hip dysplasia that did not undergo PAO for surgical correction, and (6) previous surgery to the surgical area (Table 1).

Figure 1.

CONSORT (Consolidated Standards of Reporting Trials Diagram) diagram of patient selection. FAI, femoroacetabular impingement syndrome; PAO, periacetabular osteotomy.

Table 1

Inclusion and Exclusion Criteria ^a

Inclusion criteria

1. Patients with a diagnosis of FAIS
2. Patients between the ages of 14 and 65
3. Patients who completely responded to postoperative outcomes survey
4. Patients whose records (including perioperative examinations and surgical records) were available

Exclusion criteria

1. Patients <14 or >65 years old
2. Tönnis grade 2-3 (moderate or severe) osteoarthritis or minimum superior joint space width <2.0 mm
3. Patients who underwent hip arthroscopy for a diagnosis other than FAIS
4. Patients who did not respond or incompletely responded to postoperative outcomes survey
5. Patients with a diagnosis of hip dysplasia who did not undergo PAO for surgical correction
6. Patients with previous surgery to the surgical area

FAIS, femoroacetabular impingement syndrome; PAO, periacetabular osteotomy.

Patient medical records were retrospectively reviewed to determine whether or not each patient had a concomitant diagnosis of hip dysplasia. Records were then reviewed to confirm that dysplastic patients underwent correction of the dysplasia with PAO. Patients were then placed into 1 of 2 groups: dysplastic patients that underwent staged arthroscopy for FAIS followed by PAO and a control group that consisted of nondysplastic patients that solely underwent arthroscopy for FAIS. Acetabular dysplasia was defined by an LCEA or ACEA <20°.⁴⁷

Surgical Treatment and Rehabilitation Protocol

All hip arthroscopy procedures were performed without the use of a perineal post and with traction.⁴⁰ An interportal capsulotomy was performed in all cases, followed by capsular repair using nonabsorbable sutures. Labral repair was performed for all labral tears, while labral allograft reconstruction was utilized when acetabular rim trimming was required to address pincer morphology or when native labral tissue quality was inadequate, based on intraoperative assessment. Patients undergoing isolated hip arthroscopy were prescribed etodolac 400 mg twice daily for 21 days for heterotopic ossification prophylaxis and pain control, and no postoperative braces were utilized.

In patients with FAIS and concomitant acetabular dysplasia requiring combined treatment, the same hip arthroscopy techniques were employed. The hip arthroscopy and the PAO were performed in a staged fashion, with the PAO being performed after, with a mean interval of approximately 3 weeks between procedures to allow for safe performance of the second surgical intervention. In our practice, we prefer these procedures to be staged, as it can reduce the surgical time and chances of intraoperative complications. Etodolac was prescribed following hip arthroscopy and discontinued 5 days prior to the PAO. The Bernese PAO was performed as originally described, using controlled periacetabular cuts to mobilize the acetabular fragment while preserving posterior column continuity.²² The acetabulum was reoriented to optimize femoral head coverage and hip biomechanics and stabilized with internal fixation using a mean of 3 screws.

Following isolated hip arthroscopy, patients were instructed to maintain 20-lb (9-km) foot-flat weightbearing for 3 weeks, followed by progression to weightbearing as tolerated. Physical therapy was initiated within 7 days postoperatively. For patients undergoing combined hip arthroscopy and PAO, weightbearing as tolerated was permitted following hip arthroscopy; after the PAO, patients were restricted to 20-lb (9-kg) foot-flat weightbearing until radiographic evidence of osteotomy healing, at which point weightbearing was advanced as tolerated. Physical therapy was initiated after hip arthroscopy and continued following the PAO, with rehabilitation limited to early-phase strengthening until weightbearing restrictions were lifted.

Postoperative PRO Measures (PROMs)

Surveys were electronically sent to all patients potentially meeting the inclusion criteria. The postoperative surveys included the Mental Health Inventory (MHI-5), 12-item international Hip Outcome Tool (iHOT-12), Physical Function Short Form of the Hip Disability and Osteoarthritis Outcome Score (HOOS-PS), University of California Los Angeles (UCLA) Activity Scale, Adult Single Item Measure (SIM) of Physical Activity, Patient Acceptable Symptom State (PASS) single item, and repeat surgery.

The primary outcomes utilized in the current study are achievement of PASS as well as postoperative iHOT-12 scores; scores of MHI-5, HOOS-PS, UCLA Activity Scale, Adult SIM Physical Activity; unplanned repeat surgery and complications were secondary outcomes. The PASS single item is a single-item anchor question to define PASS. It asks the patient if he or she considers the current state of one's affected joint satisfactory. The iHOT-12 consists of 12 questions designed to measure both health-related quality of life and changes after treatment in young, active patients with hip disorders with a minimal clinically important difference (MCID) of 13 points.^15,29 Repeat surgery may be considered a clinical failure of surgery depending on the procedure. Minor procedures may be considered acceptable. A revision or repeat of the same operation may be considered a clinical failure. Progression to a total or partial joint replacement after a non–joint replacement surgery may be considered a clinical failure unless the goal of the index procedure was delay of joint replacement. For the purpose of this study, repeat surgery includes all patients who underwent a revision hip arthroscopy as well as those who underwent conversion to total hip arthroplasty (THA) within 2 years after the primary procedure.

The MHI-5 is designed to assess mental health and includes 5 questions referring to both positive and negative aspects of mental health, as well as questions referring to both depression and anxiety.⁸ The MHI-5 is scored from 0 (poor mental health) to 100 (good mental health).⁴² While iHOT-12 provides a good measure of hip symptoms and function with sporting and higher-level activity, the HOOS-PS is designed to assess hip symptoms with lower-level activities and assess symptoms including OA symptoms. HOOS-PS provides an estimate of functional impairment due to OA and has acceptable reliability, validity, and responsiveness to change.^9,39 The UCLA Activity Scale was originally designed to measure physical activity level for application in patients with hip or knee OA.⁴⁹ The scale captures activities ranging from “regularly participates in impact sports” down to “wholly inactive, dependent on others, and cannot leave residence.”⁴⁹ It has no floor effects in patients with symptomatic hip or knee OA.³³ The Adult SIM Physical Activity tool is a single-item PROM that has been developed and validated to assess the general physical activity level in adults.^31,34 It has good responsiveness to change in frequency of performing moderate-vigorous physical activities as verified by a hip-worn accelerometer.³⁴ The score of this PROM is equivalent to the number of days in the past week that the individual has done a total of ≥30 minutes of physical activity that was enough to raise his or her breathing rate.

Statistical Analysis

Statistical analysis was performed with a standard software package (JMP; Version 17.2; SAS Institute). A power analysis was performed for the primary and secondary outcomes of interest. Based on a priori power calculations and on a 1:5 ratio, a minimum of approximately 22 to 25 patients in the dysplasia group and 110 to 125 control patients were needed to adequately power our study and detect an MCID (13 points) in iHOT-12 scores between groups at 85% power and alpha of .95. There is no generally accepted clinically important difference in rates of achievement of PASS or revision surgery; the study was adequately powered to detect a 20% difference in the rates of the outcomes the authors believed to be clinically important. Bivariate statistics were generated with presence of acetabular dysplasia as the dependent variable. Multivariate regression analyses were then performed with PROMs (HOOS-PS, iHOT-12, and MHI-5), achievement of PASS, unplanned revision surgery and complication rates as the outcomes of interest. In the multivariate analysis, a forward selection method was utilized with inclusion of any covariate, in decreasing order of effect size, that was a significant independent predictor of the outcome or that resulted in a ≥20% change in effect size for dysplasia as a predictor of the outcome of interest. Presence of dysplasia had forced inclusion the multivariate regression models regardless of significance level. A p-value of 0.05 was set a priori.

Results

A total of 147 patients were included in this study, with 23 patients in the dysplasia group and 124 patients in the nondysplastic control group (Table 2). Among them were 25 male and 122 female patients, of age 14 to 62 years, with a mean age of 34.96 ± 12.59 years. Among patients in the dysplasia group, the mean preoperative LCEA was 16.5° and the postoperative mean following PAO was 32.1° (example in Figure 2). All patients demonstrated cam-type morphology with alpha angles >55° and underwent femoroplasty. Labral treatment was similar between groups and included labral repair, labral reconstruction, or labral repair with allograft augmentation.

Table 2

Study Group Characteristics ^a

Characteristic	Dysplasia Group(n = 23)	Control Group(n = 124)	P
Age, y	27.91 ± 8.68	36.26 ± 12.79	.003*
Sex			.046*
Male	1	24
Female	22	100
Race			.35
Asian	0	2
Black	2	11
White	21	111
Insurance type			.82
Medicaid	7	29
Medicare	1	7
Private	15	84
Tricare	0	1
Workers’ compensation	0	1
Personal injury liable party	0	2
Employment status			.86
Full-time	12	72
Part-time	1	4
Unemployed	2	15
Unemployed; student	6	21
Retired	0	2
Disabled	2	10
Side of surgery			.03*
Left	15	51
Right	8	73
History of DSM-5 disorder			.85
Yes	12	62
No	11	62
Allergies, n	1.39 ± 1.34	1.73 ± 1.94	.82
NSAID use after arthroscopy			.19
Yes	19	114
No	4	10
Tobacco use			.20
Never user	19	87
Former/current user	4	37
Body mass index, kg/m²	27.75 ± 7.19	28.34 ± 6.75	.58
Preoperative joint space width, mm	3.71 ± 0.44	3.55 ± 0.46	.10
Intra-articular corticosteroid injection prior to surgery			<.0001*
Yes	5	83
No	18	41

Data are presented as mean ± SD or n. Asterisks indicate statistical significance at P < .05. DSM-5, Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; NSAID, nonsteroidal anti-inflammatory drug.

Figure 2.

Radiographs of a patient with femoroacetabular impingement syndrome and hip dysplasia who underwent staged hip arthroscopy and subsequent periacetabular osteotomy of the left hip. (A) Preoperative radiograph showing a lateral center-edge angle of 20°. (B) Postoperative radiograph showing a lateral center-edge angle of 36°.

There were a few notable baseline differences between study group characteristics. For example, the dysplasia patients tended to be younger (dysplastic group: 27.91 ± 8.68 years; control group: 36.26 ± 12.79 years; P = .003) and female (dysplastic group: 22/23; control group: 100/124; P = .046), while the control group had more patients that had a corticosteroid injection prior to surgery (dysplastic group: 5/23; control group: 83/124; P < .0001).

In the univariate analysis (Table 3), no differences were identified between groups with regard to iHOT-12 scores (mean ± SD: dysplasia cases, 67.2 points; controls, 62.1; P = .45), achievement of PASS (cases, 69.56%; controls, 54.84%; P = .18), or unplanned repeat surgery. Seven (30%) patients of the dysplasia cohort underwent planned hardware removal. A total of 21.7% (5/23) of dysplastic patients required revision (hip arthroscopy) surgery, while 14.5% (18/124) of nondysplastic patients required revision (hip arthroscopy) surgery (P = .40) both for various causes such as new labral tears and capsular dehiscence. There were also no differences in postoperative mental health measures (MHI-5) (P = .78) or postoperative activity scores (UCLA Activity Scale, P = .24; Adult SIM Physical Activity, P = .08). Finally, there were no differences in rate of complications between the 2 groups. Only 1 of 23 (4.3%) dysplastic patients experienced a deep vein thrombosis (DVT) after surgery and 1 of 23 (4.3%) experienced a fall. Three of 124 (2.4%) nondysplastic patients experienced a DVT, 2 of 124 (1.6%) experienced a fall, and 1 of 124 (0.8%) experienced symptoms relating to lateral femoral cutaneous nerve injury (P = .76).

Table 3

2-Year Patient-Reported Outcome Measures ^a

Measure	Dysplasia Group(n = 23)	Control Group(n = 124)	P
MHI-5	77.17 ± 21.19	78.51 ± 16.13	.78
iHOT-12	67.20 ± 29.83	62.05 ± 30.53	.45
HOOS-PS	75.00 ± 25.54	70.65 ± 25.20	.39
UCLA Activity Scale	6.04 ± 2.10	5.66 ± 2.23	.24
Adult SIM-PA	3.91 ± 1.65	3.11 ± 2.15	.08
PASS single item			.18
Yes	16	68
No	7	56
Repeat surgery			.40
Same hip (unplanned), n (%)	5 (21.7)	18 (14.5)
Postoperative complication types			.76
Deep vein thrombosis	1	3
Fall	1	2
Lateral femoral cutaneous nerve injury	0	1

Data are presented as mean ± SD or n unless otherwise indicated. HOOS-PS, Physical Function Short Form of the Hip Disability and Osteoarthritis Outcome Score; iHOT, international Hip Outcome Tool; MHI, Mental Health Inventory; PASS, Patient Acceptable Symptom State; SIM-PA, Single Item Measure of Physical Activity; UCLA, University of California Los Angeles.

In the multivariate analysis (Table 4), dysplasia remained a nonsignificant predictor of outcomes after adjustment for preoperative factors. Preoperative joint space width was a significant predictor (per-mm decrease: odds ratio, 4.17; 95% CI, 1.49-11.1; P = .006) of revision surgery as well as a confounder (>20% change in effect size) of dysplasia status as a predictor of revision surgery. However, dysplasia status remained a nonsignificant predictor of revision surgery with or without adjustment for preoperative joint space width.

Table 4

Independent Predictors of Survey Outcomes ^a

	Estimated Change in Outcome	P
iHOT-12
Dysplasia present, yes	2.58 (3.45)	.46
PASS
Dysplasia present, yes	1.88 (0.72-5.00)	.19
Repeat surgery
Preoperative joint space width, mm, per unit decrease	4.17 (1.49-11.10)	.006*
Dysplasia present, yes	2.12 (0.58-7.70)	.26

Data are presented as odds ratio (95% CI) or (SE). Asterisk indicates statistical significance at P < .05. iHOT, international Hip Outcome Tool; PASS, Patient Acceptable Symptom State.

Discussion

In this examination of 23 patients with acetabular dysplasia and FAIS undergoing staged PAO following hip arthroscopy compared with 124 patients with FAIS without dysplasia treated with arthroscopy alone, no significant differences in 2-year outcomes were identified. Specifically, there were no differences in 2-year iHOT-12 scores, rates of achievement of PASS, or rates of unplanned revision hip arthroscopy or THA. The aim of this study was not to advocate for or against PAO, but rather to provide outcome data to young and active patients facing staged surgical treatment for FAIS and acetabular dysplasia. These findings suggest that, with appropriate treatment, patients undergoing staged hip arthroscopy and PAO can expect outcomes comparable with those of patients with isolated FAIS treated with arthroscopy alone.

Previous studies have reported very good outcomes in patients with FAIS and hip dysplasia who undergo hip arthroscopy and PAO in a staged fashion. Gilat et al¹⁴ and Lee et al²⁵ both reported significant improvement in PROs at 2 years after the second surgery was performed in both young and older patients. Performing both surgeries in a single stage yields PROs that are comparable with those achieved with a staged approach.³⁵ Nonetheless, in our experience the staged fashion can result in safer procedures reducing both surgical time and the odds of complication. In our study, the groups’ sole difference was the presence (or absence) of hip dysplasia and a PAO performed to address that pathology. As outcomes were very similar, that helps clinicians to reconfirm that a PAO is an outstanding procedure when patients are chosen correctly, as it has been reported before.⁶

Several studies have reported inferior outcomes in patients with FAIS and acetabular dysplasia treated with arthroscopy alone.^1,24,36,44 To our knowledge, this is the first study demonstrating that the addition of PAO following hip arthroscopy results in outcomes similar to those of nondysplastic patients undergoing arthroscopy for FAIS. These findings are particularly relevant for patient counseling, as they suggest that the need for an additional, more complex procedure does not adversely affect short-term outcomes when both intra-articular pathology and structural dysplasia are appropriately addressed.

Domb et al¹⁰ reported favorable outcomes in 13 patients undergoing combined hip arthroscopy and PAO, with significant correction of acetabular coverage and high patient satisfaction at long-term follow-up. In their cohort, mean LCEA improved from 14.4° to 30.6° and mean ACEA from 13.3° to 30.6°.⁹ In the present study, similar correction was achieved, with mean LCEA improving from 16.5° to 32.1° following staged hip arthroscopy and PAO.¹⁰ Of note, for 2 patients in the study, the pre- or postoperative LCEA measurements were not available, so these were excluded from the above mean determination. This suggests that sufficient correction with PAO surgery was achieved.

The comparable outcomes observed between groups emphasize that the primary difference between cohorts was the addition of the PAO procedure. Despite the increased complexity of PAO, outcomes remained similarly favorable, supporting PAO as an effective surgical intervention when indicated.

Previous studies have demonstrated a high prevalence of concomitant intra-articular pathology in dysplastic hips. Ross et al³⁸ identified labral tears and acetabular chondral lesions in 65.8% and 68.5% of hips, respectively, while Kohno et al²³ reported labral tears in 96% and chondral damage in 88% of patients undergoing combined arthroscopy and PAO.^{1,2,7,20,23,38} However, this does not answer the question of whether or not the intra-articular pathology needs to be addressed in addition to addressing the dysplasia itself.

Some studies have suggested limited benefit to routine concomitant arthroscopy at the time of PAO. Beaulé et al⁴ reported no significant differences in short-term outcomes between PAO with arthroscopy and PAO alone in a multicenter randomized controlled trial. However, in that study, arthroscopy was limited to labral repair without FAO. Given that bony correction of cam morphology is a cornerstone of FAIS treatment and has been shown to improve functional outcomes and cartilage health, the lack of osteoplasty may have limited the potential benefit of arthroscopy in that cohort.³ This distinction may partially explain why the present study, which included comprehensive treatment of FAIS, demonstrated favorable and comparable outcomes following staged hip arthroscopy and PAO.

Limitations

This study represents the first direct comparison of outcomes between patients with FAIS with concomitant acetabular dysplasia treated with staged hip arthroscopy and PAO and nondysplastic patients with FAIS treated with hip arthroscopy alone. The use of multiple validated PROMs allowed for a broad assessment of hip-specific function and overall patient well-being. In addition, all procedures were performed by a single surgeon at a single institution, limiting variability in surgical technique and perioperative care. There are several limitations of this study. The first limitation is the absence of a control group consisting of patients treated with isolated PAO, which precludes determination of whether PAO alone may sufficiently improve symptoms related to FAI and acetabular dysplasia. The subset of patients who underwent arthroscopic treatment of FAIS followed by PAO only included 23 patients. The study was therefore not powered to compare PROs other than iHOT-12, rates of PASS, or rates of revision surgery. Additional PROs related to physical function, mental health, and activity level were reported for descriptive purposes in the univariate analysis and could not be included in the multivariate analysis because of increased risk for type 1 error (incorrect report of a significant difference between groups when none actually exists). Significant difference was found in the 2 patient groups when considering age, with the dysplastic group being younger on average than the nondysplastic group, and sex, with a higher percentage of female patients in the dysplastic group. This is similar to what has been reported in other studies, but it may not be representative of the population at large.³⁷ Regardless, no differences in the outcomes of interest were found between study groups, with or without adjustment for these baseline demographic differences.

Conclusion

The treatment of acetabular dysplasia and concomitant FAIS with hip arthroscopy followed by PAO yielded results that indicate that these patients have clinical outcomes similar to that of patients with FAIS without dysplasia treated with arthroscopy alone, with no significant differences in PROs at 2-year follow-up. The findings of this study may assist surgeons and clinicians in clinical decision-making for patients with concomitant FAIS and acetabular dysplasia and in appropriately setting patient expectations regarding staged surgical management.

Footnotes

Final revision submitted February 27, 2026; accepted March 3, 2026.

The authors declared that they have no conflicts of interest in the authorship and publication of this contribution.

Ethical approval for this study was obtained from Indiana University (IRB No. 22175).

ORCID iDs

Allison R. Garden

Andrea M.E. Palazzolo-Ray

Andrew J. Darling

Joshua T. Finerty

Manuel A. Romero-Padron

Nicholas R. Kossoff

Joshua S. Everhart

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