Purpose
The purpose of this study was to compare outcomes after hip arthroscopy for femoroacetabular
impingement syndrome (FAIS) in patients with borderline hip dysplasia and hip instability
defined radiographically using the femoroepiphyseal acetabular roof (FEAR) index and
in patients without radiographic evidence of hip instability.
Methods
Data from consecutive patients with borderline hip dysplasia (lateral center edge
angle between 18˚-25˚) who underwent primary hip arthroscopy between April 2012 and
June 2017 for the treatment of FAIS were analyzed. Baseline demographic data, radiographic
parameters, preoperative, and 2-year postoperative patient-reported outcome measures
were collected. The FEAR index was measured by 3 different observers. Patients with
an average FEAR index ≥2˚ were categorized as having radiographic evidence of instability
as previously published. The analysis was powered to detect a minimal clinically important
difference (MCID) for each outcome score. Statistical analysis was performed as appropriate
to compare patients with FEAR index ≥2 and <2°.
Results
A total of 140 patients met the inclusion criteria. The average age and body mass
index of included patients was 31.7 ± 13.2 (P < .325) years and 25.1 ± 5.6 kg/m2 (P < .862). There were no statistically significant demographic differences between
the groups. Nineteen (13.0%) patients were found to have a FEAR index of over 2˚.
The FEAR index <2° and FEAR index ≥2° groups had a mean preoperative FEAR index (standard
deviation, range) of −7.0 (5.2, −26.8 to 1.9) and 4.8 (2.5, 2.0-11.8), respectively.
The interrater intraclass correlation coefficient was 0.96. Postoperative patient-reported
outcomes and rates of MCID and patient-acceptable symptomatic state achievement were
not statistically different between the radiographically stable and unstable groups.
(p>0.05 for all).
Conclusion
Patients with borderline hip dysplasia and radiographic evidence of hip instability,
as measured by the FEAR index (≥2°), achieve similar improvement in 2-year outcomes
compared to those with radiographically stable hips after arthroscopic treatment of
FAIS.
Clinical Relevance
Retrospective Level III cohort study
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to ArthroscopyAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Trends and demographics in hip arthroscopy in the United States.Arthroscopy. 2013; 29: 661-665
- Age-related trends in hip arthroscopy: A large cross-sectional analysis.Arthroscopy. 2015; 31: 2307-2313.e2
- A review of hip arthroscopy and its role in the management of adult hip pain.Iowa Orthop J. 2005; 25: 172-179
- Surgical outcomes in the treatment of concomitant mild acetabular dysplasia and femoroacetabular impingement: A systematic review.Arthroscopy. 2020; 36: 1176-1184
- Do patients with borderline dysplasia have inferior outcomes after hip arthroscopic surgery for femoroacetabular impingement compared with patients with normal acetabular coverage?.Am J Sports Med. 2017; 45: 2116-2124
- Mild or borderline hip dysplasia: Are we characterizing hips with a lateral center-edge angle between 18° and 25° appropriately?.Am J Sports Med. 2019; 47: 112-122
- The femoro-epiphyseal acetabular roof (fear) index: A new measurement associated with instability in borderline hip dysplasia?.Clin Orthop Relat Res. 2017; 475: 861-869
- Biomechanics of the locomotor apparatus.Contributions on the functional anatomy of the locomotor apparatus. 1st Ed. Springer-Verlag, Berlin1980
- Theoretical study of the decrease in the femoral neck anteversion during growth.Cells Tissues Organs. 2002; 171: 269-275
- Rehabilitation after hip arthroscopy: A movement control-based perspective.Clin Sports Med. 2016; 35: 503-521
- Patients with borderline hip dysplasia achieve clinically significant outcome after arthroscopic femoroacetabular impingement surgery: A case-control study with minimum 2-year follow-up.Am J Sports Med. 2019; 47: 2636-2645
- Is the femoro-epiphyseal acetabular roof (FEAR) index on MRI a relevant predictive factor of instability in a borderline dysplastic hip?.Bone Joint J. 2019; 101-B: 1578-1584
- Hip dislocation or subluxation after hip arthroscopy: A systematic review.Arthroscopy. 2016; 32: 1428-1434
- Trends of hip arthroscopy in the setting of acetabular dysplasia.J Hip Preserv Surg. 2018; 5: 267-273
- Patients with borderline hip dysplasia achieve clinically significant improvement after arthroscopic femoroacetabular impingement surgery: A case-control study with a minimum 5-year follow-up.Am J Sports Med. 2020; 48: 1616-1624
- Arthroscopic capsular plication and labral preservation in borderline hip dysplasia: Two-year clinical outcomes of a surgical approach to a challenging problem.Am J Sports Med. 2013; 41: 2591-2598
- A multicenter study of radiographic measures predicting failure of arthroscopy in borderline hip dysplasia: Beware of the Tönnis angle.Am J Sports Med. 2020; 48: 1608-1615
- The anterior center edge angle: A study of 102 volunteers.Joint Bone Spine. 2004; 71: 221-223
- The acetabular wall index for assessing anteroposterior femoral head coverage in symptomatic patients.Clin Orthop Relat Res. 2012; 470: 3355-3360
- Systematic review of hip arthroscopy for femoroacetabular impingement: The importance of labral repair and capsular closure.Arthroscopy. 2019; 35: 646-656
- Role of the acetabular labrum in load support across the hip joint.J Biomech. 2011; 44: 2201-2206
- Role of the acetabular labrum and the iliofemoral ligament in hip stability: An in vitro biplane fluoroscopy study.Am J Sports Med. 2011; 39: 85S-91S
- Hip capsular closure: A biomechanical analysis of failure torque.Am J Sports Med. 2017; 45: 434-439
Article info
Publication history
Published online: October 25, 2021
Accepted:
October 7,
2021
Received:
March 23,
2021
See commentary on page 1516Footnotes
S.J.N Allosource, Arthrex, Athletico, DJ-Orthopaedics, Linvatec, and Miomed; and personal fees from Ossur, Smith & Nephew, Springer, and Stryker, outside the submitted work. Full ICMJE author disclosure forms are available for this article online, as supplementary material.
Identification
Copyright
© 2021 by the Arthroscopy Association of North America
