The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): an international consensus statement

The evolution of femoroacetabular impingement surgical management as a model for introducing new surgical techniques

Introducing new surgical techniques and concepts can be difficult. There are many hurdles to overcome initially, such as the learning curve, equipment and technique development, before a standard of care can be established. In the past, new surgical techniques have been developed, and even widely accepted, before any scientific evaluation has been made. At that stage, it may be too late properly to evaluate the effectiveness of treatments, as the objectiveness and/or randomisation process may be obstructed. Since the introduction of evidence-based medicine (EBM), there have been high standards of scientific rigour to prove the efficacy of treatments. Based on the nature of evidence-based acceptance, innovations cannot be subjected to this final process before their evolution process is complete and, as a result, there is a need for the staged scientific development of new surgical techniques that should be adopted. This paper presents a model for this kind of stepwise introduction based on the actual evolution of FAI syndrome surgery. By following a scientific algorithmic methodology, new surgical techniques and concepts can be introduced in a stepwise manner to ensure the evidence-based progression of knowledge.

Total volume of cam deformity alone predicts outcome in arthroscopy for femoroacetabular impingement

PURPOSE

Rates for arthroscopic surgery for femoroacetabular impingement (FAI) are rising and there is growing concern related to the effectiveness and costs associated with this treatment. There is a general lack of consensus as to the criteria for surgical selection of patients. The purpose of this study was to determine whether patient outcome following arthroscopic surgery for FAI could be predicted based on the size and location of deformity. The specific questions were: (1) what is the morphology of FAI in terms of size and location of deformity in a cohort of patients selected for surgery? (2) Do morphological factors predict postoperative improvement in hip scores? (3) Do morphological factors predict preoperative hip scores? (4) Are there clusters of morphological factors which explain postsurgical improvement in hip scores?

MATERIALS AND METHODS

Computer tomography (CT) surgical plans of 90 hips in 79 patients who had undergone primary hip arthroscopy for FAI were retrospectively reviewed. Four parameters for the femur and acetabulum were created: total depth of deformity, maximal depth, extent and the position of maximal deformity. This data were compared with prospectively acquired preoperative and postoperative patient outcome data using generalised linear models.

RESULTS

The cohort comprised 33 males and 46 females aged 37.9 (18-61). The majority (74%) had mixed morphology, 23% isolated cam, and 3% isolated pincer. Overall, the bone depth was greatest and more extensive on the femur. Increased total additional cam deformity alone predicted poorer postoperative outcome (p = 0.045). None of the morphological factors were related to preoperative scores and there was no association between the meta-variables and postoperative outcome.

CONCLUSIONS

The results of this study indicate that a greater total volume of cam deformity led to poorer postoperative patient outcome scores at 1 year. This information provides the surgeon with more accurate patient-specific data for prediction of expected outcomes.

LEVEL OF EVIDENCE

Level III diagnostic.

Preoperative Duration of Symptoms Is Associated With Outcomes 5 Years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

PURPOSE

To determine the effect of the preoperative duration of femoroacetabular impingement syndrome (FAIS)-associated symptoms on clinical outcomes at a minimum of 5 years after hip arthroscopy.

METHODS

We identified FAIS patients who underwent primary hip arthroscopy between January 2012 and January 2014 with a minimum of 5 years' follow-up. Patient demographic characteristics and clinical outcomes, comprising the Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), pain score, and satisfaction score, were analyzed. The minimal clinically important difference, patient acceptable symptomatic state, and substantial clinical benefit were calculated. Patients were stratified based on the preoperative duration of symptoms: less than 2 years versus 2 years or longer. Multivariate regressions were constructed to determine the association between the preoperative symptom duration and clinical outcomes at 5 years after hip arthroscopy.

RESULTS

A total of 310 patients were included with a mean age (±standard deviation) of 34.1 ± 11.9 years and body mass index of 25.3 ± 5.1. The study group showed statistically significant improvements in the HOS-ADL, HOS-SS, mHHS, pain score, and satisfaction score (P < .001 for all). A preoperative duration of symptoms of 2 or more years was an independent predictor of worse HOS-ADL, HOS-SS, mHHS, and pain score (P < .05 for all). Furthermore, a longer duration of symptoms was associated with a lower likelihood of achieving the minimal clinically important difference for the HOS-ADL (odds ratio [OR], 0.53; P = .037), HOS-SS (OR, 0.38; P = .003), and mHHS (OR, 0.43; P = .009); the patient acceptable symptomatic state for the HOS-SS (OR, 0.44; P = .006) and mHHS (OR, 0.46; P = .006) but not the HOS-ADL despite trending toward significance (OR, 0.59; P = .098); and substantial clinical benefit for the HOS-ADL (OR, 0.50; P = .011), HOS-SS (OR, 0.52; P = .020), and mHHS (OR, 0.47; P = .007).

CONCLUSIONS

Patients with a preoperative duration of FAIS-associated symptoms of 2 or more years prior to hip arthroscopy experience inferior outcomes and a lower frequency of clinically significant outcome improvement than patients with a shorter duration of symptoms at medium-to long-term follow-up.

LEVEL OF EVIDENCE

Level III, retrospective comparative trial.

In Vivo Pelvic and Hip Joint Kinematics in Patients With Cam Femoroacetabular Impingement Syndrome: A Dual Fluoroscopy Study

Femoroacetabular impingement syndrome (FAIS) may alter the kinematic function of the hip, resulting in pain and tissue damage. Previous motion analysis studies of FAIS have employed skin markers, which are prone to soft tissue artifact and inaccurate calculation of the hip joint center. This may explain why the evidence linking FAIS with deleterious kinematics is contradictory. The purpose of this study was to employ dual fluoroscopy (DF) to quantify in vivo kinematics of patients with cam FAIS relative to asymptomatic, morphologically normal control participants during various activities. Eleven asymptomatic, morphologically normal controls and seven patients with cam FAIS were imaged with DF during standing, level walking, incline walking, and functional range of motion activities. Model-based tracking calculated the kinematic position of the hip by registering projections of three-dimensional computed tomography models with DF images. Patients with FAIS stood with their hip extended (mean [95% confidence interval], -2.2 [-7.4, 3.1]°, flexion positive), whereas controls were flexed (5.3 [2.6, 8.0]°; p = 0.013). Male patients with cam FAIS had less peak internal rotation than the male control participants during self-selected speed level-walking (-0.2 [-6.5, 6.1]° vs. -9.8 [-12.2, -7.3]°; p = 0.007) and less anterior pelvic tilt at heel-strike of incline (5°) walking (3.4 [-1.0, -7.9]° vs. 9.8 [6.4, 13.2]°; p = 0.032). Even during submaximal range of motion activities, such as incline walking, patients may alter pelvic motion to avoid positions that approximate the cam lesion and the acetabular labrum. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:823-833, 2020.

The relationship between cam morphology and hip and groin symptoms and signs in young male football players

Background

Conflicting and limited high‐quality prospective data are available on the associations between cam morphology and hip and groin symptoms and range of motion (ROM).

Objectives

This cross‐sectional cohort study investigated associations between cam morphology presence, size and duration and symptoms and ROM.

Methods

Academy male football players (n = 49, 17‐24 years) were included. Standardized antero‐posterior pelvic and frog‐leg lateral radiographs were obtained at baseline, 2.5‐ and 5‐year follow‐up. The femoral head‐neck junction was quantified by:

Visual score. Cam morphology (flattening or prominence), large cam (prominence).

Alpha angle. Cam morphology (≥60°), large cam (≥78°).

Cam morphology duration was defined as long (first present at baseline) or short (only from 2.5‐ to 5‐year follow‐up). Current symptoms at 5‐year follow‐up were assessed using a hip and groin pain question and by the “Hip and Groin Outcome Score” (HAGOS). HAGOS scores were categorized into: most symptoms (≥2 domains in lowest interquartile range [IQR]), least symptoms (≥2 domains in highest IQR). Hip ROM was measured by goniometry at 5‐year follow‐up.

Results

Large cam morphology based on visual score was associated with hip and groin pain (23.8% vs. 7.1%, OR: 3.17, CI: [1.15‐8.70], P = .026), but not with HAGOS scores. Cam morphology presence, size, and duration were associated with limited flexion of around 6° and/or 3° to 6° for internal rotation.

Conclusion

Cam morphology presence, size, and duration were associated with limited hip flexion and/or internal rotation, but differences might not exceed the minimal clinical important difference. Whether cam morphology results in symptoms is uncertain.

Travel Distance Does Not Affect Outcomes in Hip Preservation Surgery: A Case for Centers of Excellence

Background:

Previous studies have evaluated the effect of distance to high-volume centers on outcomes after joint replacement. However, there is limited evidence on whether this distance has an effect on outcomes after undergoing hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS).

Purpose:

To determine whether increased distance from a patient’s home to his or her primary orthopaedic clinic has an influence on the ability to achieve the minimal clinically important difference (MCID) on outcome measures after surgery for FAIS.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A retrospective cohort analysis was performed on patients undergoing surgery for FAIS by a single surgeon from January 2012 through January 2017. A total of 692 patients were identified and split into 2 groups: driving distance of <50 miles from our institution (referral group) and driving distance of <50 miles from our institution (local group). Preoperative and 2-year postoperative scores on patient-reported outcome measures (PROMs), including the Hip Outcome Score Activities of Daily Living and Sport-Specific subscales, International Hip Outcome Tool–12, and modified Harris Hip Score, were assessed. Patients achieving the MCID on any included PROM were analyzed using a chi-square analysis. Logistic regression was performed to determine whether driving distance and other demographic variables of interest had an effect on achieving the MCID. Study data were analyzed using PatientIQ, a cloud-based research and analytics platform for health care.

Results:

There were 647 patients who completed 2-year follow-up and were included in the analysis. Of these patients, 116 (17.9%) were identified as being ≥50 miles from their orthopaedic provider, and 531 (82.1%) were identified as having a driving distance of <50 miles. A total of 100 patients (86.2%) in the referral group reached the MCID, and 476 patients (89.6%) in the local group reached the MCID. There was no statistically significant difference in reaching the MCID on any of the included PROMs between the 2 groups (P = .364). The same result held when controlling for a number of factors including age, body mass index, and adjusted gross income with logistic regression.

Conclusion:

When controlling for a number of factors including age, body mass index, and adjusted gross income, distance to a high-volume hip arthroscopic surgery center did not have an effect on postoperative outcome scores or achieving the MCID 2 years after undergoing surgery for FAIS.

[Diagnostic algorithm "FAI and sports hernia" : Results of the consensus meeting for groin pain in athletes]

As a result of the complexity and diversity of diseases in the region of the groin, differentiation of the various soft-tissue and bone pathologies remains a challenge for differential diagnosis in routine clinical practice. In the case of athletes with pain localized in the area of the groin, femoroacetabular impingement (FAI) and athlete's groin must be considered as important causes of the groin pain, whereby the common occurrence of double pathologies further complicates diagnosis. Despite the importance of groin pain and its differential diagnoses in everyday clinical practice, there has been a lack of recognized recommendations for diagnostic procedure to date. To this end, a consensus meeting was held in February 2017, in which a group composed equally of groin and hip surgeons took part. With the formulation of recommendations and the establishment of a practicable diagnostic path, colleagues that are involved in treating such patients should be sensitized to this issue and the quality of the diagnosis of groin pain improved in routine clinical practice.

Location of Intra- and Extra-articular Hip Impingement Is Different in Patients With Pincer-Type and Mixed-Type Femoroacetabular Impingement Due to Acetabular Retroversion or Protrusio Acetabuli on 3D CT-Based Impingement Simulation

BACKGROUND

Diagnosis and surgical treatment of hips with different types of pincer femoroacetabular impingement (FAI), such as protrusio acetabuli and acetabular retroversion, remain controversial because actual 3-dimensional (3D) acetabular coverage and location of impingement cannot be studied via standard 2-dimensional imaging. It remains unclear whether pincer hips exhibit intra- or extra-articular FAI.

PURPOSE

(1) To determine the 3D femoral head coverage in these subgroups of pincer FAI, (2) determine the impingement-free range of motion (ROM) through use of osseous models based on 3D-computed tomography (CT) scans, and (3) determine the osseous intra-and extra-articular 3D impingement zones by use of 3D impingement simulation.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

This is a retrospective, comparative, controlled study involving 70 hips in 50 patients. There were 24 patients (44 hips) with symptomatic pincer-type or mixed-type FAI and 26 patients (26 hips) with normal hips. Surface models based on 3D-CT scans were reconstructed and compared for hips with acetabular retroversion (30 hips), hips with protrusio acetabuli (14 hips), and normal asymptomatic hips (26 hips). Impingement-free ROM and location of impingement were determined for all hips through use of validated 3D collision detection software based on CT-based 3D models. No abnormal morphologic features of the anterior iliac inferior spine were detected.

RESULTS

(1) Mean total femoral head coverage was significantly (P < .001) increased in hips with protrusio acetabuli (92% ± 7%) and acetabular retroversion (71% ± 5%) compared with normal hips (66% ± 6%). (2) Mean flexion was significantly (P < .001) decreased in hips with protrusio acetabuli (104°± 9°) and acetabular retroversion (116°± 6°) compared with normal hips (125°± 13°). Mean internal rotation in 90° of flexion was significantly (P < .001) decreased in hips with protrusio acetabuli (16°± 12°) compared with normal hips (35°± 13°). (3) The prevalence of extra-articular subspine impingement was significantly (P < .001) higher in hips with acetabular retroversion (87%) compared with hips with protrusio acetabuli (14%) and normal hips (0%) and was combined with intra-articular impingement. The location of anterior impingement differed significantly (P < .001) between hips with protrusio acetabuli and normal hips.

CONCLUSION

Using CT-based 3D hip models, we found that hips with pincer-type and mixed-type FAI have significantly larger femoral head coverage and different osseous ROM and location of impingement compared with normal hips. Additionally, intra- and extra-articular subspine impingement was detected predominantly in hips with acetabular retroversion. Acetabular rim trimming during hip arthroscopy or open surgical hip dislocation should be performed with caution for these hips. Patient-specific analysis of location of impingement using 3D-CT could theoretically improve diagnosis and planning of surgical treatment.

Defining Meaningful Functional Improvement on the Visual Analog Scale for Satisfaction at 2 Years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

PURPOSE

To (1) define Substantial Clinical Benefit (SCB), Patient Acceptable Symptomatic State (PASS), and Minimal Clinically Important Difference (MCID) for the visual analog scale (VAS) Satisfaction in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS), and (2) identify preoperative predictors of achieving each outcome end-point.

METHODS

Data from consecutive patients who underwent primary hip arthroscopy between November 2014 and January 2017 were prospectively collected and retrospectively analyzed. Inclusion criteria consisted of patients with clinical and radiographic diagnosis of FAIS, who failed nonoperative treatment, underwent primary hip arthroscopy to address the FAIS, and had at minimum 2-year follow-up. Baseline data and postoperative patient-reported outcome scores were recorded at 2 years postoperatively. To quantify clinical significance of outcome achievement on the VAS)Satisfaction, we calculated MCID, PASS, and SCB for this outcome measure. A multivariate logistic regression analysis was used to identify preoperative predictors of achieving SCB, PASS, and MCID satisfaction.

RESULTS

A total of 335 patients were included in the final analysis, with an average age and body mass index (BMI) of 32.8 (standard deviation ± 12.4) years and 25.2 (standard deviation ± 5.3), respectively, and the majority being female (69.3%). The values on the VAS satisfaction were identified to represent MCID, PASS, and SCB, respectively: 52.8, 80.9, and 89.7. The rates of achieving clinically significant improvement on the VAS Satisfaction was 85.6%, 68.1%, and 56.9% for MCID, PASS, and SCB, respectively. A larger preoperative alpha angle was predictive for achieving SCB (odds ratio [OR], 1.076; P = .046), whereas lower BMI (OR, 0.955; P = .047) and larger preoperative alpha angle (OR, 1.12; P = .025) were predictors for achieving PASS.

CONCLUSIONS

This study identified threshold VAS satisfaction scores of 52.8, 80.9, and 89.7 for achieving MCID, SCB, and PASS, respectively, at 2-year follow-up following hip arthroscopy for FAIS. Furthermore, preoperative variables including larger preoperative alpha angles and lower BMI are predictors of achieving superior clinical satisfaction.

LEVEL OF EVIDENCE

Level IV, Case Series.

The Prevalence of Radiographic Findings of Structural Hip Deformities for Femoroacetabular Impingement in Patients With Hip Pain

BACKGROUND

Radiography is the initial imaging modality used to evaluate femoroacetabular impingement (FAI), and diagnostic radiographic findings are well-established. However, the prevalence of these radiographic findings in patients with hip pain is unknown.

PURPOSE

The purpose was 3-fold: (1) to determine the overall prevalence of radiographic FAI deformities in young patients presenting with hip pain, (2) to identify the most common radiographic findings in patients with cam-type FAI, and (3) to identify the most common radiographic findings in patients with pincer-type FAI.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A geographic database was used to identify patients aged 14 to 50 years with hip pain between the years 2000 to 2016. The following were evaluated on radiographs: cam type: typical pistol grip deformity, alpha angle >55°; pincer type: crossover sign (COS), coxa profunda or protrusio acetabuli, lateral center edge angle (LCEA) ≥40°, Tönnis angle <0°; and mixed type: both cam- and pincer-type features. Posterior wall sign (PWS) and ischial spine sign (ISS) were also evaluated. The prevalence of each was determined. Descriptive statistics were performed on all radiographic variables.

RESULTS

There were 1893 patients evaluated, and 1145 patients (60.5%; 1371 hips; 374 male and 771 female; mean age, 28.8 ± 8.4 years) had radiographic findings consistent with FAI. Of these hips, 139 (10.1%) had cam type, 245 (17.9%) had pincer type, and 987 (72.0%) had mixed type. The prevalence of a pistol grip deformity and an alpha angle >55° was 577 (42.1%) and 1069 (78.0%), respectively. The mean alpha angle was 66.9°± 10.5°. The prevalence of pincer-type radiographic findings was the following: COS, 1062 (77.5%); coxa profunda, 844 (61.6%); ISS, 765 (55.8%); PWS, 764 (55.7%); Tönnis angle <0°, 312 (22.8%); LCEA ≥40°, 170 (12.4%); and protrusio acetabuli, 7 (0.5%).

CONCLUSION

The overall prevalence of radiographic findings consistent with FAI in young patients with hip pain was 60.5%. Radiographic findings for mixed-type FAI were the most prevalent. The most common radiographic finding for cam-type FAI was an alpha angle >55°. The most common radiographic finding for pincer-type FAI was the COS.

Defining the Clinically Meaningful Outcomes for Arthroscopic Treatment of Femoroacetabular Impingement Syndrome at Minimum 5-Year Follow-up

BACKGROUND

Minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) have gained prominence as important variables in the orthopaedic outcomes literature. In hip preservation surgery, much attention has been given to defining early clinically meaningful outcome; however, it is unknown what represents meaningful patient-reported outcome improvement in the medium to long term.

PURPOSE

(1) To define MCID, PASS, and SCB at a minimum 5 years after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and (2) to evaluate the time-dependent nature of MCID, PASS, and SCB.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients undergoing primary hip arthroscopy for FAIS between January 2012 and March 2014 were included. Clinical and demographic data were collected in an institutional hip preservation registry. MCID, PASS, and SCB were calculated for each outcome score including the Hip Outcome Score-Activities of Daily Living subscale (HOS-ADL), Hip Outcome Score-Sport-Specific subscale (HOS-SS), modified Harris Hip Score (mHHS), and International Hip Outcome Tool (iHOT-12) at 1, 2, and 5 years. MCID was calculated by use of a distribution-based method, whereas PASS and SCB were calculated by use of an anchor method.

RESULTS

The study included 283 patients with a mean ± SD age of 34.2 ± 11.9 years. The mean changes in 1-year, 2-year, and 5-year scores, respectively, required to achieve MCID were as follows: HOS-ADL (8.8, 9.7, 10.2); HOS-SS (13.9, 14.3, 15.2); mHHS (6.9, 9.2, 11.4); and iHOT-12 (15.1, 13.9, 15.1). The threshold scores for achieving PASS were as follows: HOS-ADL (89.7, 88.2, 99.2); HOS-SS (72.2, 76.4, 80.9); mHHS (84.8, 83.3, 83.6); and iHOT-12 (69.1, 72.2, 74.3). Last, the threshold scores for achieving SCB scores were as follows: HOS-ADL (89.7, 91.9, 94.6); HOS-SS (78.1, 77.9, 85.8); mHHS (86.9, 85.8, 94.4); and iHOT-12 (72.6, 76.8, 87.5). More patients achieved MCID, SCB, and PASS at 2-year compared with 1-year follow-up; however, by 5 years, fewer patients had achieved clinically meaningful outcome (minimum 1-, 2-, and 5-year follow-up, respectively: MCID, 82.6%, 87.3%, 79.3%; PASS, 67.6%, 74.9%, 67.5%; SCB, 62.3%, 67.2%, 56.6%).

CONCLUSION

The greatest proportion of patients achieved MCID, PASS, and SCB at 2-year follow-up after arthroscopic treatment of FAIS compared with 1- and 5-year time points. Improvements were maintained out to 5-year follow-up, although the proportion of patients achieving clinical significance was slightly decreased.

Altered gait mechanics are associated with severity of chondropathy after hip arthroscopy for femoroacetabular impingement syndrome

BACKGROUND

Suboptimal patient-reported function and movement impairments often persist after hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Individuals with FAIS with preoperative cartilage pathology (ie. chondropathy) demonstrate distinct movement patterns and have worse post-operative outcomes. It is unknown whether the presence of chondropathy after surgery negatively affects movement and function.

RESEARCH QUESTION

Do sagittal plane gait mechanics differ based on chondropathy severity following arthroscopy for FAIS?

METHODS

A cross-sectional walking gait analysis was performed for 25 participants post-arthroscopy (2.48 ± 1.38y) and 12 healthy controls (HCs). Peak total support moment (TSM) and relative contributions of the hip, knee, and ankle were calculated during loading response. The Hip Osteoarthritis MRI Scoring System was used to categorize the FAIS group into no-mild or moderate-severe chondropathy groups based on 3 T magnetic resonance imaging of their surgical hip. The interactions of group by limb were evaluated for kinetic variables, covaried by gait speed.

RESULTS

Groups did not differ based on age, BMI and sex distribution (P ≥ 0.14). 13 participants with FAIS presented with moderate-severe chondropathy and 12 presented with no-mild chondropathy. Participants with moderate-severe chondropathy walked significantly slower than both other groups (P = 0.006) and demonstrated lower peak TSM than those with no-mild chondropathy (P = 0.002). Participants with no-mild chondropathy demonstrated lower hip (61.5 %) and greater ankle (17.7 %) contributions to the TSM on the involved limb compared to the moderate-severe group (hip:73.4 %, P = 0.07; ankle:10.5 %, P = 0.007).

SIGNIFICANCE

Slower gait speed alone did not explain the lower TSM strategy in participants with moderate-severe chondropathy. Interestingly, the joint contribution strategy of this group was not different than HCs. Participants with no-mild chondropathy demonstrated a TSM strategy that shifted the demand away from their hip and toward their ankle. Given the small sample size, and large variability in joint strategies, future work needs to examine whether these alterations in gait strategy, with or without advanced chondropathy, impact patient function.

Sleep quality and nocturnal pain in patients with femoroacetabular impingement and acetabular dysplasia

Background

Femoroacetabular impingement (FAI) syndrome and acetabular dysplasia (AD) are common pathologies that lead to pain in the young adult hip. Nocturnal pain in these patients is often reported, yet little is known regarding the effect of these hip pathologies on overall sleep quality. The purpose of this study was to evaluate sleep quality in patients with AD and FAI syndrome.

Methods

This cross-sectional study consisted of 115 patients who complained of hip pain secondary to either FAI syndrome or AD. One hundred fifteen patients with hip pain secondary to FAI syndrome and AD were assessed using the Hip Outcome Score (HOS), Modified Harris Hip Score (mHHS), and then Hip disability and Osteoarthritis Outcome Score (HOOS). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Multiple linear regression, with adaptive LASSO variable selection, was used to assess factors associated with sleep quality.

Results

Of the 115 patients, 62 had a diagnosis of FAI syndrome and 53 with AD. The mean age was 34.55 ± 11.66 (age range: 14 to 58 years), 76.52% had an ASA classification of 1 (ASA range: 1 to 3), and all Tonnis grades were either 0 or 1. The mean PSQI global score for all patients was 8.46 ± 4.35 (PSQI range: 0 to 21), indicating poor sleep quality. The adaptive LASSO-penalized least squares multiple linear regression revealed that HOOS Pain, SF-12 Role Emotional, and SF-12 Mental Health significantly predicted Sleep Quality (Adjusted R2 = 0.4041). Sleep quality improved as pain, emotional problems, and mental health improved.

Conclusion

Patients with symptomatic FAI syndrome and AD have poor sleep quality. Worsening pain from a patient’s hip pathology is associated with poor sleep, even prior to the onset of osteoarthrosis of the hip. Patients presenting with hip pain from FAI syndrome and AD should be screened for sleep disturbance and may benefit from a multidisciplinary treatment approach.

Labral calcification plays a key role in hip pain and symptoms in femoroacetabular impingement

BACKGROUND

Hip osteoarthritis (HOA) is the most common hip disorder and a major cause of disability in the adult population, with an estimated prevalence of end-stage disease and total hip replacement. Thus, the diagnosis, prevention, and treatment of the early stages of the disease in young adults are crucial to reduce the incidence of end-stage HOA. The purpose of this study was to determine whether (1) a relationship among the inflammatory status of labrum and synovium collected from patients with femoroacetabular impingement (FAI) would exist; and (2) to investigate the associations among the histopathological features of joint tissues, the pre-operative symptoms and the post-operative outcomes after arthroscopic surgery.

METHODS

Joint tissues from 21 patients undergoing hip arthroscopy for FAI were collected and their histological and immunohistochemical features were correlated with clinical parameters.

RESULTS

Synovial mononuclear cell infiltration was observed in 25% of FAI patients, inversely correlated with the hip disability and osteoarthritis outcome score (HOOS) pain and function subscales and with the absolute and relative change in total HOOS. All the labral samples showed some pattern of degeneration and 67% of the samples showed calcium deposits. The total labral score was associated with increased CD68 positive cells in the synovium. The presence of labral calcifications, along with the chondral damage worsened the HOOS post-op symptoms (adjusted R-square = 0.76 p = 0.0001).

CONCLUSIONS

Our study reveals a relationship between the histologic labral features, the synovial inflammation, and the cartilage condition at the time of FAI. The presence of labral calcifications, along with the cartilage damage and the synovitis negatively affects the post-operative outcomes in patients with FAI.

Midterm-clinical Outcomes after Hip Arthroscopy in Middle-aged Patients with Early Osteoarthritis

Purpose

Although the number of hip arthroscopies is rapidly increasing in non-elderly patients, outcomes of this procedure in middle-aged patients are not well documented or clearly understood. The purpose of this study was to evaluate the clinical and radiological outcomes after hip arthroscopy in middle-aged patients with early osteoarthritis.

Materials and Methods

This retrospective study analyzed 189 patients with early osteoarthritis of various diagnoses aged 40 years or older who underwent hip arthroscopy between January 2010 and December 2015. Clinical (e.g., modified Harris hip score [mHHS], hip outcome score-activities of daily living [HOS-ADL], visual analogue scale [VAS] for pain, range of motion) and radiological (change of Tönnis grade) outcomes were assessed at a minimum of 3-year follow-up.

Results

The mean preoperative and final mHHS and HOS-ADL improved from 61.2 and 60.6 to 79.5 and 81.8, respectively, while the VAS pain score decreased from 6.3 to 3.2 (P<0.001). Although the mean range of internal rotation and flexion increased from 14.2 and 100.7° preoperatively to 30.4 and 110.6° at 1-year postoperatively, they decreased slightly to 27.4 and 105.4° at the final follow-up, respectively. Eight cases (4.2%) underwent revision arthroscopic surgery and three cases (1.6%) were converted to total hip arthroplasty.

Conclusion

Patients with early-stage osteoarthritis of various diagnoses achieved improved clinical outcomes. Therefore, using hip arthroscopy in middle-aged patients with early osteoarthritis, it is possible to achieve good surgical options.

Squat and gait biomechanics 6 months following hip arthroscopy for femoroacetabular impingement syndrome

The purpose of this study was to (i) assess whether squat and gait biomechanical measures improve in patients with femoroacetabular impingement syndrome (FAIS) 6 months after surgery compared to pre-operative measures and (ii) compare biomechanical properties to controls without FAIS. In this prospective study, biomechanical data during a double leg squat task and gait for 15 FAIS patients and 9 controls were collected using three-dimensional motion analysis. Data were collected in the FAIS group at two-time points, pre-operatively and 6-month post-operatively following arthroscopic hip surgery, and at a single time point for the healthy controls. Independent sample's t-test were used to compare the FAIS group to the controls, and paired samples t-test were used to determine within-group differences before and after hip arthroscopy in the FAIS group. The results indicated that there were significant within-group increases for sagittal plane moment rate during the double leg squat task (P = 0.009) between the pre-operative and post-operative time points for the FAIS group. Between-group differences showed that FAIS patients pre-operatively exhibit slower squat velocities during the descent (P = 0.005) and ascent phase (P = 0.012) of a double leg squat when compared healthy controls. Reduced hip external rotation moments during gait (P = 0.02) were also found between FAIS patients pre-operatively and controls. In conclusion, alterations in hip biomechanics are present before surgery for FAIS when compared to healthy controls, and joint mechanics change 6 months after surgery. However, the biomechanical differences during a double leg squat and gait were minimal.

Gender-Specific Sexual Activity After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Position Matters

BACKGROUND

There is limited evidence on the safety of return to sexual activity after hip arthroscopy.

AIM

To determine the positional safety of sexual activity after hip arthroscopy relative to hip instability and/or impingement risk.

STUDY DESIGN

This study is an observational study.

METHODS

12 common sexual positions were identified based on previous research. Gender-specific hip motion was then assessed for the possibility of postarthroscopic hip instability (due to disruption of iliofemoral ligament [interportal capsulotomy] repair) and/or impingement (labral or capsular compressive stress with disrupted repair) for all 12 positions (both right and left hips; 15 unique male and 14 unique female positions). Instability risk was defined as greater than 0° hip extension, greater than 30° external rotation (ER), or greater than 30° abduction. Impingement risk was defined as greater than 90° hip flexion, greater than 10° internal rotation, and greater than 10° adduction.

OUTCOMES

A majority of both male and female sexual positions caused either instability or impingement, with only 4 positions in women and 4 positions in men deemed "safe" by avoiding excessive hip motion.

RESULTS

Return to sexual activity after hip arthroscopy may cause instability in 10/15 of male positions and 5/14 female positions. Most male positions (6/10) were at risk for instability because of excessive ER. 2 positions were unstable because of a combination of ER and extension, one was due to extension, and one abduction. In female instability positions, all 5 were unstable because of excessive abduction. Impingement may be observed in 5 of 15 male positions and 6 of 14 female positions. In male impingement positions, all were due to excessive adduction. 4 female positions risked impingement due to excessive flexion and 2 positions due to internal rotation.

CLINICAL IMPLICATIONS

This study demonstrates risks that should be considered when counseling patients preoperatively and postoperatively regarding sexual activity.

STRENGTHS & LIMITATIONS

This study closely models a hip preservation patient population by using 2 young and otherwise healthy individuals. The most significant limitation of this investigation was its basis with only 2 young healthy volunteers (one male, one female) in a single motion capture session using surface-based spherical retroreflective markers from a previous investigation.

CONCLUSION

After hip arthroscopy, patients need to be made aware of the possibility of hip instability (10 of 15 men; 5 of 14 women) and impingement (5 of 15 men; 6 of 14 women) due to excessive hip motion that may compromise their outcome. Morehouse H, Sochacki KR, Nho SJ, et al. Gender-Specific Sexual Activity After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Position Matters. J Sex Med 2020;17:658-664.

Leg dominance as a risk factor for femoroacetabular impingement syndrome

One etiological factor of femoroacetabular impingement syndrome (FAIS) is high impact athletics involving deep hip flexion, axial loading and jumping during skeletal development. Previous work has established that there is physiologic asymmetry of the lower limbs regarding function, with the dominant limb being primarily responsible for propulsion and kicking while the non-dominant limb is responsible for stability and planting. The authors hypothesize that the dominant limb will be more likely to undergo hip arthroscopy for symptomatic FAIS. Four hundred and sixty-nine patients at a single surgical center who underwent primary or revision hip arthroscopy for cam-type FAIS were identified. Patients were asked to identify their dominant lower extremity, defined as the lower extremity preferred for kicking. Sixty patients who indicated bilateral leg dominance were excluded. It was assumed that with no association between limb dominance and the need for surgery, the dominant side would have surgery 50% of the time. Enrichment for surgery in the dominant limb was tested for using a one-sample test of proportions, determining whether the rate differed from 50%. The enrichment for surgery on the dominant side was 57% (95% confidence interval 52–62%) which was significantly different from the rate expected by chance (50%), P = 0.003. No other significant differences were noted between groups. Limb dominance appears to be an etiological factor in the development of cam-type FAIS. Patients are more likely to undergo arthroscopic treatment of FAIS on their dominant lower extremity, although the non-dominant lower extremity frequently develops FAIS as well.

Evaluation of Statistical Shape Modeling in Quantifying Femoral Morphologic Differences Between Symptomatic and Nonsymptomatic Hips in Patients with Unilateral Femoroacetabular Impingement Syndrome

Purpose

To determine whether statistical shape modeling can detect subtle morphologic differences in the shape of the proximal femur that correlate with clinical findings of unilateral femoroacetabular impingement syndrome.

Methods

Patients who had diagnoses of unilateral femoroacetabular impingement syndrome and who had existing computed tomography scans of their pelvises were included. Three-dimensional shape models in the form of triangle meshes were generated from the computed tomography images. Statistical shapes of cam-type and normal hips were compared to identify structural differences.

Results

The study included 33 hips in 17 subjects. Of the subjects, 7 (41.1%) were male, and 10 (58.9%) were female. The subjects ranged in age from 17-60 years of age (mean 36.3 ± 11.0 years old). The statistical shape modeling found mean shapes and modes after optimizing the groupwise correspondence. Symptomatic hips demonstrated 1 mm of thickening as compared to the femoral necks of asymptomatic hips, corresponding to cam lesions.

Conclusions

Symptomatic cam deformities were an average of 1 mm more prominent in the femoral neck region as compared to the asymptomatic hips when using statistical shape modeling. The present study provides a proof of the concept that statistical shape modeling can be used to examine and help define cam morphology and that subtle morphologic differences may account for developing femoroacetabular impingement syndrome.

Clinical Relevance

Using the methods presented in this study, it would be possible to define cam and pincer morphologies by creating statistical shape models, and this work could potentially lead to the development of a new classification system for femoroacetabular impingement syndrome lesions.

Application of Machine Learning for Predicting Clinically Meaningful Outcome After Arthroscopic Femoroacetabular Impingement Surgery

BACKGROUND

Hip arthroscopy has become an important tool for surgical treatment of intra-articular hip pathology. Predictive models for clinically meaningful outcomes in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) are unknown.

PURPOSE

To apply a machine learning model to determine preoperative variables predictive for achieving the minimal clinically important difference (MCID) at 2 years after hip arthroscopy for FAIS.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were analyzed for patients who underwent hip arthroscopy for FAIS by a high-volume fellowship-trained surgeon between January 2012 and July 2016. The MCID cutoffs for the Hip Outcome Score-Activities of Daily Living (HOS-ADL), HOS-Sport Specific (HOS-SS), and modified Harris Hip Score (mHHS) were 9.8, 14.4, and 9.14, respectively. Predictive models for achieving the MCID with respect to each were built with the LASSO algorithm (least absolute shrinkage and selection operator) for feature selection, followed by logistic regression on the selected features. Study data were analyzed with PatientIQ, a cloud-based research and analytics platform for health care.

RESULTS

Of 1103 patients who met inclusion criteria, 898 (81.4%) had a minimum of 2-year reported outcomes and were entered into the modeling algorithm. A total of 74.0%, 73.5%, and 79.9% met the HOS-ADL, HOS-SS, and mHHS threshold scores for achieving the MCID. Predictors of not achieving the HOS-ADL MCID included anxiety/depression, symptom duration for >2 years before surgery, higher body mass index, high preoperative HOS-ADL score, and preoperative hip injection (all P < .05). Predictors of not achieving the HOS-SS MCID included anxiety/depression, preoperative symptom duration for >2 years, high preoperative HOS-SS score, and preoperative hip injection, while running at least at the recreational level was a predictor of achieving HOS-SS MCID (all P < .05). Predictors of not achieving the mHHS MCID included history of anxiety or depression, high preoperative mHHS score, and hip injections, while being female was predictive of achieving the MCID (all P < .05).

CONCLUSION

This study identified predictive variables for achieving clinically meaningful outcome after hip arthroscopy for FAIS. Patient factors including anxiety/depression, symptom duration >2 years, preoperative intra-articular injection, and high preoperative outcome scores are most consistently predictive of inability to achieve clinically meaningful outcome. These findings have important implications for shared decision-making algorithms and management of preoperative expectations after hip arthroscopy for FAI.

Differences between race and sex in measures of hip morphology: a population-based comparative study

OBJECTIVE

This paper aims to (i) identify differences in measures of hip morphology between four racial groups using anteroposterior (AP) hip x-rays, and (ii) examine whether these differences vary by sex.

METHODS

912 hip x-rays (456 individuals) from four racial groups (European Caucasians, American Caucasians, African Americans and Chinese) were obtained. Males and females (45-75 years) with no radiographic hip OA (Kellgren and Lawrence < Grade 2 or Croft < Grade 1) were included. Eleven features of hip joint morphology were analysed. Linear regression with generalised estimating equations (GEE) was used to determine race and sex differences in hip morphology. Post-hoc Bonferroni procedure was used to adjust for multiple comparisons.

RESULTS

The final analysis included 875 hips. Chinese hips showed significant differences for the majority of measures to other racial groups. Chinese were characterised by more shallow and narrow acetabular sockets, reduced femoral head coverage, smaller femoral head diameter, and a lesser angle of alignment between the femoral neck and shaft. Variation was found between other racial groups, but with few statistically significant differences. The average of lateral centre edge angle, minimum neck width and neck length differed between race and sex (p-value for interaction < 0.05).

CONCLUSIONS

Significant differences were found in measures of morphology between Chinese hips compared to African Americans or Caucasian groups; these may explain variation in hip OA prevalence rates between these groups and the lower rate of hip OA in Chinese. Sex differences were also identified, which may further explain male-female prevalence differences for OA.

The Influence of Lumbosacral Spine Pathology on Minimum 2-Year Outcome After Hip Arthroscopy: A Nested Case-Control Analysis

BACKGROUND

Previous literature has examined the association between lumbosacral pathology and hip pathomechanics. However, the effect of lumbosacral pathologies and previous lumbosacral surgery on achieving meaningful outcomes after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) has yet to be studied conclusively.

PURPOSE

To determine whether a history of lumbosacral spine pathology has an influence on achieving minimal clinically important differences (MCIDs) after hip arthroscopy for FAIS.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients undergoing hip arthroscopy for FAIS by a single, fellowship-trained orthopaedic surgeon between January 2012 and April 2017 with minimum 2-year follow-up were retrospectively reviewed. Patients with a history of lumbosacral spine pathology (eg, lumbosacral fusion, disc or vertebral pathology, or history of lumbosacral fractures) were matched 1:2 by age, body mass index, and sex to patients without spine pathology. Clinical outcomes including the Hip Outcome Score-activities of daily living subscale (HOS-ADL), HOS-sports subscale (HOS-SS), modified Harris Hip Score (mHHS), international Hip Outcome Tool-12 (iHOT-12), visual analog scale (VAS) pain, and VAS satisfaction were compared between the groups using an independent t test. The threshold of every outcome score for achieving MCID was calculated separately for each group and frequencies were compared.

RESULTS

A total of 83 of 108 eligible patients with lumbosacral pathology were identified and matched to 166 patients without any spine pathology. When compared with the non-spine pathology group, the lumbosacral pathology group had significantly lower 2-year postoperative outcome score averages across all reported outcome tools (all P < .001). There were significant differences in the proportion achieving the threshold for HOS-ADL (60.6% vs 80.0%; P = .004), HOS-SS (57.6% vs 82.1%; P < .001), mHHS (66.7% vs 81.7%; P = .025), and iHOT-12 (54.8% vs 87.6%; P < .001) scores for MCID when comparing the lumbosacral and nonlumbosacral pathology groups.

CONCLUSION

Patients with a history of lumbosacral pathology achieved significantly lower short-term meaningful clinical outcomes after undergoing hip arthroscopy for FAIS when compared with patients without spine pathology. The present study findings have implications for preoperative patient screening, shared decision-making processes/expectation management, and rehabilitation strategies.

Resolving anterior hip pain in a young male footballer following arthroscopic surgery for Femoroacetabular Impingement Syndrome: A case report

BACKGROUND

There appear to be limited studies available regarding the conservative management of patients following hip joint arthroscopic surgery, or investigating reasons for which patients still report hip and groin pain post surgery.

OBJECTIVES

Treatment was applied to restore spino-pelvic mechanics and to reduce soft tissue restrictions in hip joint motion. Neuromuscular movement control and work capacity exercises were encouraged to support the integrity of the hip joint and spino-pelvic complex.

CLINICAL FEATURES

A 22-year-old male footballer, (height 190cm and weight 82kg) presented reporting an eighteen-month history of hip and groin pain, having previously undergone bilateral arthroscopic surgery twelve months earlier for Femoroacetabular Impingement Syndrome. Strength measurements were recorded using the MicroFET 2 Wireless Digital Handheld Dynamometer. Trunk muscular endurance was evaluated with Sorenson test.

RESULTS

Five treatment consultations over a five-week period resulted in pain reduction, (Visual Analogue Scale 8/10 to 0/10). Improvement in range of motion, right hip flexion (70-100°) and left (80-100°), right internal rotation (30-45°) and left (40-45°). Improvement in strength, specifically right hip flexion (0.29-0.43Nm/kg, 48%) and right hip abduction (0.35-0.46Nm/kg, 31%). Improvement in trunk muscular endurance increased 41% from 170 seconds to 240 seconds.

CONCLUSION

This case report supports the rationale that the post arthroscopic management of Femoroacetabular Impingement Syndrome, should include both treatment to address spino-pelvic restrictions, if appropriate, combined with exercises that specifically target hip flexor strength. However, a larger randomized study would provide a clearer understanding for the management of this particular subset of patients.

Consensus recommendations on the classification, definition and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018

There is no agreement on how to classify, define or diagnose hip-related pain-a common cause of hip and groin pain in young and middle-aged active adults. This complicates the work of clinicians and researchers. The International Hip-related Pain Research Network consensus group met in November 2018 in Zurich aiming to make recommendations on how to classify, define and diagnose hip disease in young and middle-aged active adults with hip-related pain as the main symptom. Prior to the meeting we performed a scoping review of electronic databases in June 2018 to determine the definition, epidemiology and diagnosis of hip conditions in young and middle-aged active adults presenting with hip-related pain. We developed and presented evidence-based statements for these to a panel of 37 experts for discussion and consensus agreement. Both non-musculoskeletal and serious hip pathological conditions (eg, tumours, infections, stress fractures, slipped capital femoral epiphysis), as well as competing musculoskeletal conditions (eg, lumbar spine) should be excluded when diagnosing hip-related pain in young and middle-aged active adults. The most common hip conditions in young and middle-aged active adults presenting with hip-related pain are: (1) femoroacetabular impingement (FAI) syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without a distinct osseous morphology (labral, chondral and/or ligamentum teres conditions), and that these terms are used in research and clinical practice. Clinical examination and diagnostic imaging have limited diagnostic utility; a comprehensive approach is therefore essential. A negative flexion-adduction-internal rotation test helps rule out hip-related pain although its clinical utility is limited. Anteroposterior pelvis and lateral femoral head-neck radiographs are the initial diagnostic imaging of choice-advanced imaging should be performed only when requiring additional detail of bony or soft-tissue morphology (eg, for definitive diagnosis, research setting or when planning surgery). We recommend clear, detailed and consistent methodology of bony morphology outcome measures (definition, measurement and statistical reporting) in research. Future research on conditions with hip-related pain as the main symptom should include high-quality prospective studies on aetiology and prognosis. The most common hip conditions in active adults presenting with hip-related pain are: (1) FAI syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without distinct osseous morphology including labral, chondral and/or ligamentum teres conditions. The last category should not be confused with the incidental imaging findings of labral, chondral and/or ligamentum teres pathology in asymptomatic people. Future research should refine our current recommendations by determining the clinical utility of clinical examination and diagnostic imaging in prospective studies.

Best Practice Guidelines for Hip Arthroscopy in Femoroacetabular Impingement: Results of a Delphi Process

BACKGROUND

Treatment algorithms for the arthroscopic management of femoroacetabular impingement (FAI) syndrome remain controversial because of a paucity of evidence-based guidance. Consequently, notable variability in clinical practice exists between different practitioners, necessitating expert consensus. The purpose of this study is to establish best practice guidelines (BPG) using formal techniques of consensus building among a group of experienced hip arthroscopists driven by the results of a systematic review and meta-analysis. The scope of these guidelines includes preoperative recommendations, intraoperative practices, and postoperative protocols.

METHODS

The validated Delphi process and the nominal group technique (NGT), used by the Centers for Disease Control and Prevention and the peer-reviewed orthopaedic literature, were used to formally derive consensus among 15 surgeons in North America. Participants were surveyed for current practices, presented with the results of a meta-analysis and systematic literature review, and asked to vote for or against the inclusion of nonleading, impartially phrased items during three iterative rounds while preserving the anonymity of participants' opinions. Agreement greater than 80% was considered consensus, and items near consensus (70% to 80% agreement) were further queried using the NGT in a moderated group session at the American Orthopaedic Society for Sports Medicine annual meeting.

RESULTS

Participants had a mean of 12.3 years of practice (range: 1 to 29 years) and performed an annual mean of 249 (range 100 to 500+) hip arthroscopies, with a combined total of approximately 52,580 procedures. Consensus was reached for the creation of BPG consisting of 27 preoperative recommendations, 15 intraoperative practices, and 10 postoperative protocols. The final checklist was supported by 100% of participants.

CONCLUSION

We developed the first national consensus-based BPG for the surgical and nonsurgical management of FAI. The resulting consensus items can serve as a tool to reduce the variability in preoperative, intraoperative, and postoperative practices and guide further research for the arthroscopic management of FAI.

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

Purpose

To (1) investigate trends in kinesiophobia and pain catastrophizing after hip arthroscopy for femoroacetabular impingement syndrome (FAIS), and (2) determine whether kinesiophobia and pain catastrophizing scores are associated with achieving minimal clinically important difference (MCID) for any of the hip-specific patient-reported outcome questionnaires.

Methods

Patients undergoing primary hip arthroscopy for treatment of FAIS between December 2016 and March 2017 were prospectively enrolled. Patients received the Tampa Scale of Kinesiophoibia-11 (TSK-11) and Pain Catastrophizing Scale (PCS) questionnaires preoperatively, 6 months, and 1 year postoperatively. They also received the hip-specific patient-reported outcome questionnaires (Hip Outcome Score Activities of Daily Living and Sport-Specific subscales, modified Harris Hip Score, and International Hip Outcome Tool-12), as well as visual analog scale for satisfaction and pain preoperatively and 1-year postoperatively. The threshold for achieving MCID was determined for each hip outcome tool, and patients achieving MCID were compared with those who did not.

Results

A total of 85 (80.2%) patients (mean age: 33.7 ± 12.4 years; female: 75.3%) were included in the final analysis. At 1-year follow-up, there was a significant reduction in TSK-11 scores (26.22 ± 5.99 to 18.70 ± 6.49; P < .001) and PCS scores (17.81 ± 10.13 to 4.77 ± 7.57; P < .001) when compared with preoperative scores. 1-year PCS scores were significantly lower in patients achieving MCID compared with patients failing to achieve MCID (3.2 ± 4.4 vs 10.8 ± 15.2; P = .006). There were no significant differences in TSK-11 scores between those achieving and not achieving MCID.

Conclusions

Patient kinesiophobia and pain catastrophizing both show significant improvements 1 year after undergoing hip arthroscopy for FAIS. However, pain catastrophizing scores at 1 year are significantly greater in patients not achieving MCID, whereas no association was identified between kinesiophobia and likelihood for MCID achievement. This suggests PCS may be a more useful tool than TSK-11 during postoperative rehabilitation for identifying patients at risk for not achieving MCID.

Level of Evidence

Level II, prospective case series.

Young elite Alpine and Mogul skiers have a higher prevalence of cam morphology than non-athletes

PURPOSE

To investigate the prevalence of cam morphology in (1) a group of young elite Mogul and Alpine skiers compared with non-athletes and (2) between the sexes.

METHOD

The hip joints of 87 subjects [n = 61 young elite skiers (29 females and 32 males) and n = 26 non-athletes (17 females and 9 males)] were examined using MRI, for measurements of the presence of cam morphology (α-angle ≥ 55).

RESULTS

The skiers had a significantly higher prevalence of cam morphology compared with the non-athletes (49% vs 19%, p = 0.009). A significant difference (p < 0.001) was also found between females and males, where 22% of the females and 61% of the males had cam morphology. Among the skiers, there was also a significant difference (p < 0.001) between the sexes, where 28% of the females and 68% of the males had cam morphology. This difference between the sexes was not found in the non-athletic group. No significant differences were found between Mogul and Alpine skiers.

CONCLUSION

Young male elite skiers have a higher prevalence of cam morphology of the hips compared with non-athletes.

LEVEL OF EVIDENCE

II.

Combining results from hip impingement and range of motion tests can increase diagnostic accuracy in patients with FAI syndrome

PURPOSE

Clinical examination is an important part in the diagnosis of femoroacetabular impingement (FAI) syndrome. However, knowledge on reliability and validity of clinical diagnostic tests is scarce. The aims were to evaluate the inter-rater agreement and diagnostic accuracy of clinical tests to detect patients with FAI syndrome.

METHODS

Eighty-one patients (49% women) were recruited. Two experienced raters performed impingement and range of motion (ROM) tests. Three criteria had to be fulfilled for the diagnosis of FAI syndrome: (1) symptoms; (2) CAM and/or Pincer morphology; and (3) being responder to intra-articular block injection. For inter-rater agreement, the Cohen's kappa statistics were used (0.41-0.60 = moderate, 0.61-0.80 = substantial agreement). For diagnostic accuracy, sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

Anterior impingement test (AIMT), FADIR test and FABER test showed kappa values above 0.6. All passive hip ROM, except extension, had kappa values above 0.4. AIMT and FADIR showed the highest sensitivity, i.e., 80%, with a specificity of 26% and 25%, respectively. Passive hip ROM in internal rotation with neutral hip position had a sensitivity of 29% and a specificity of 94%.

CONCLUSION

The AIMT, FADIR and FABER tests were reliable between two experienced raters, while results from different raters for hip ROM should be interpreted with caution. The AIMT and FADIR test can only be used to rule out patients with FAI syndrome, while evaluation of ROM in internal rotation with neutral position may be more suitable to rule in patients with FAI syndrome.

LEVEL OF EVIDENCE

II.

Defining the Minimal Clinically Important Difference in Athletes Undergoing Arthroscopic Correction of Sports-Related Femoroacetabular Impingement: The Percentage of Possible Improvement

BACKGROUND

Measures of clinically meaningful improvement in patient-reported outcomes within orthopaedics are becoming a minimum requirement to establish the success of an intervention.

PURPOSE

To (1) define the minimal clinically important difference (MCID) at 2 years postoperatively in competitive athletes undergoing hip arthroscopic surgery for symptomatic, sports-related femoroacetabular impingement utilizing existing anchor- and distribution-based methods and (2) derive a measure of the MCID using the percentage of possible improvement (POPI) method and compare against existing techniques.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

There were 2 objective outcome measures-the modified Harris Hip Score (mHHS) and 36-Item Short Form Health Survey (SF-36)-administered at baseline and 2 years postoperatively. External anchor questions were used to determine the MCID through mean change, mean difference, and receiver operating characteristic (ROC) techniques. Distribution-based calculations consisted of 0.5 SD, effect size, and standard error of measurement techniques. The POPI was calculated alongside each technique as an achieved percentage change of maximum available improvement for each athlete relative to the individual baseline score. The impact of the preoperative baseline score on the MCID was assessed by assigning athletes to groups determined by baseline percentiles. Statistical analysis was performed, with P < .05 considered significant.

RESULTS

There were 576 athletes (96% male; mean age, 25.9 ± 5.7 years). The MCID score change (and POPI) for the mHHS and SF-36 ranged from 2.4 to 16.7 (21.6%-63.6%) and from 3.3 to 24.9 (22.1%-57.4%), respectively. The preoperative threshold value for achieving the ROC-determined MCID was 80.5 and 86.5 for the mHHS and 70.1 and 72.4 for the SF-36 for the patient-reported outcome measure (PROM) score- and POPI-calculated MCID, respectively. Through the commonly used mean change method, 40.0% (mHHS) and 42.4% (SF-36) of athletes were unable to achieve the MCID because of high baseline scores and PROM ceiling effects compared with 0% when the POPI technique was used. A highly significant difference for the overall MCID was observed between preoperative baseline percentile groups for the mHHS (P = .014) and SF-36 (P = .004) (improvement in points), while there was no significant difference between groups for either the mHHS (P = .487) or SF-36 (P = .417) using the POPI technique.

CONCLUSION

The MCID defined by an absolute value of improvement was unable to account for postoperative progress in a large proportion of higher functioning athletes. The POPI technique negated associated ceiling effects, was unrestricted by the baseline score, and may be more appropriate in quantifying clinically important improvement.

Epidemiology of hip and groin injuries in Swedish male first football league

PURPOSE

This study aimed to investigate the incidence, pattern, and burden of hip/groin injuries in Swedish professional male football players over five consecutive seasons.

METHODS

Injury history from 16 football teams in the Swedish male first football league was evaluated during five consecutive seasons. The team's medical staff recorded team exposure and time-loss injuries prospectively between 2012 and 2016.

RESULTS

In total, 467 time-loss injuries located in the hip/groin area were recorded among 1,687 professional male football players, with an overall incidence and burden of 0.82/1,000 h and 15.6/1,000 h, respectively. There appeared to be an increased risk of hip/groin injuries during the last two seasons (2015-2016); however, the difference was not statistically significant (n.s). Recurrent injury rate was relatively low (14%), and overuse injuries accounted for the majority of injuries and absence days. Muscle injuries were the main injury type, while kicking and sprinting/running were the primary causes of injury. Goalkeepers had the lowest percentage of injuries and absence days.

CONCLUSION

Hip/groin injuries are a substantial problem in football, but does not seem to be an increasing phenomenon in the Swedish male first football league. Index and overuse injuries accounted for the majority of injuries and absence days. Thus, the focus should be on preventing hip/groin injuries to lower the injury rate. These new findings should be taken into consideration when designing and implementing preventive training interventions.

LEVEL OF EVIDENCE

II.

Good 5-year outcomes after arthroscopic treatment for femoroacetabular impingement syndrome

PURPOSE

The purpose of the present study was to evaluate the outcome of arthroscopic treatment for femoroacetabular impingement (FAI) syndrome 5 years post-surgery using patient-reported outcome scores (PROMs) validated for a young and active population with hip complaints.

METHODS

Patients were prospectively included in the study. A total of 184 patients [males = 110 (59.8%), females = 74 (40.2%)], with mean age 38.0, underwent arthroscopic treatment for FAI syndrome and were analysed. Preoperatively and at the 5-year follow-up, patients completed a set of self-administered web-based PROMs consisting of the International Hip Outcome Tool (iHOT-12), the Copenhagen Hip and Groin Outcome Score (HAGOS), the Hip Sports Activity Scale (HSAS), the EuroQoL-5 Dimension Questionnaire (EQ-5D), the EQ-Visual Analogue Scale (VAS) and the VAS for overall hip function and overall satisfaction. The Wilcoxon signed rank test was used to compare preoperative PROM values with those obtained at the 5-year follow-up.

RESULTS

A comparison of preoperative PROM scores and those obtained at the 5-year follow-up revealed statistically significant improvements for all outcome scores (p < 0.05), except for the HSAS score, which were unchanged; iHOT-12 (42.9 vs 67.2), HAGOS different subscales (50.2 vs 69.6, 55.7 vs 76.1, 59.2 vs 72.3, 41.1 vs 66.4, 30.8 vs 60.2, 31.6 vs 60.4), EQ-5D (0.570 vs 0.742), EQ-VAS (66.6 vs 74.4), HSAS (3.13 vs 3.17) and VAS for overall hip function (47.9 vs 69.2). At the 5-year follow-up, 154 patients reported that they were satisfied with surgery (84.6%). Survivorship at the 5-year follow-up was 86.4%.

CONCLUSION

Arthroscopic treatment for FAI syndrome yields good patient-reported outcome at the 5-year follow-up.

LEVEL OF EVIDENCE

II.

Two-Year Patient-Reported Outcomes for Patients Undergoing Revision Hip Arthroscopy with Capsular Incompetency

PURPOSE

To determine clinical outcomes of patients undergoing revision hip arthroscopy for failure to improve with magnetic resonance imaging (MRI) and intraoperative evidence of a capsular incompetency as compared with (1) patients undergoing revision hip arthroscopy without evidence of a capsular incompetency and (2) patients undergoing primary surgery for femoroacetabular impingement syndrome (FAIS) at a minimum follow up of 2 years.

METHODS

Data from consecutive patients undergoing revision hip arthroscopy with MRI/arthrogram-confirmed capsular incompetency between January 2012 and June 2016 were analyzed. All revision patients with capsular incompetency was matched 1:1 by age and body mass index to FAIS revision patients without capsular incompetency and primary FAIS patients. Outcomes included the Hip Outcome Score (HOS)-Activities of Daily Living (ADL), HOS-Sports Subscale (SS), Modified Harris Hip Score (mHHS), pain, and satisfaction. The minimal clinically important difference was calculated for HOS-ADL, HOS-SS, and mHHS.

RESULTS

In total, 49 patients (54.4%) of 90 undergoing revision hip arthroscopy had MRI evidence of a capsular incompetency. Most patients were female (79.6%), with a mean age of 30 ± 10.5 years and body mass index of 25.7 ± 5.5. The difference among pre- and postoperative HOS-ADL, HOS-SS, mHHS, and visual analog scale score for pain were all statistically significant (P < .05). Analysis of reported outcomes among matched groups demonstrated statistically significant differences, with the group undergoing primary surgery having the greatest 2-year outcomes. Only 66.7% of patients undergoing revision surgery with capsular incompetency achieved a minimal clinically important difference; however, there was no significant difference when compared with revision patients without capsular incompetency. When compared with patients undergoing primary surgery, the difference in frequency was statistically significant (66.7% vs 91.3%; P < .001).

CONCLUSIONS

More than one half of patients undergoing revision hip arthroscopy had MRI and intraoperative evidence of capsular incompetency. Revision arthroscopy for capsular incompetency results in significantly improved 2-year outcomes. However, patients undergoing revision for capsular incompetency and intact capsule revision patients reported significantly lower outcomes compared with primary patients.

LEVEL OF EVIDENCE

Level III, Retrospective Comparative Study.

Comparing Outcomes of Competitive Athletes Versus Nonathletes Undergoing Hip Arthroscopy for Treatment of Femoroacetabular Impingement Syndrome

BACKGROUND

A growing number of studies have examined return to sport in competitive athletes after undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS); however, few have evaluated the rate of achieving meaningful clinical outcomes in this group.

PURPOSE

To determine if competitive athletes (professional, semiprofessional, or collegiate) have better 2-year patient-reported outcomes and achieve the minimal clinically important difference (MCID) and substantial clinical benefit at higher rates when compared with nonathletes undergoing hip arthroscopy for the treatment of FAIS.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The study was a retrospective analysis of all consecutive patients who identified as either a competitive athlete or a nonathlete and had undergone hip arthroscopy for FAIS by a single fellowship-trained surgeon between January 2012 and April 2017. Patients in the 2 groups were matched 1:2 by age, sex, and body mass index. Baseline and clinical outcomes, including the Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports Subscale (HOS-SS), modified Harris Hip Score, and international Hip Outcome Tool-12, were collected preoperatively and at 2 years postoperatively and compared between the groups. The MCID and substantial clinical benefit were calculated for each group separately and compared using chi-square analysis.

RESULTS

A total of 59 competitive athletes and 118 nonathletes were included in the final analysis. Most of the competitive athletes were soccer players (23.7%), followed by softball players (10.2%) and runners (10.2%). Postoperative score comparison between competitive athletes and nonathletes demonstrated a statistically significant difference in the HOS-SS (mean ± SD, 84.5 ± 19.0 vs 76.1 ± 23.8; P = .02). Meaningful outcome analysis demonstrated that competitive athletes had a higher rate of achieving the HOS-SS threshold for the MCID (97.4% vs 82.5%; P = .021). There was no other difference in frequency of achieving the threshold for any other meaningful clinical outcome between the groups.

CONCLUSION

Hip arthroscopy for the treatment of FAIS in competitive athletes and nonathletes produced clinically meaningful outcomes in both patient groups. However, competitive athletes achieved the MCID on the HOS-SS at higher rates than nonathletes and had significantly higher scores at 2 years postoperatively on the HOS-SS.

Editorial Commentary: A Commentary on a Meta-analysis of Short-Term Outcomes

Hip pain is prevalent and costly, and young patients with hip femoroacetabular impingement have similar levels of pain and quality of life to older patients with hip osteoarthritis. Hip arthroscopic surgery for femoroacetabular impingement is increasing in prevalence, and the benefits of operative treatment compared with nonoperative treatment require consideration. Hip arthroscopy should not be a first-line treatment but can be necessary in cases in which high-quality, exercise-based nonsurgical treatment options have been exhausted. Patients should be informed that surgery is not necessarily cost-effective and may have an increased risk of comorbidities such as chronic pain and insomnia. Patient-reported outcomes may improve by up to 20% with either surgery or physical therapy but are not likely to return to those seen in patients without hip pain. Although most patients return to sport after hip arthroscopy, the ability to participate at a preinjury level is seen in fewer than a quarter of patients. Return-to-sport rates with physiotherapist-led nonoperative treatment are not known.

Short term outcomes of hip arthroscopy on hip joint mechanics and cartilage health in patients with femoroacetabular impingement syndrome

BACKGROUND

Femoroacetabular acetabular impingement syndrome consists of abnormal hip joint morphology resulting in painful hip joint impingement. Hip arthroscopy corrects the abnormal morphology and reduces clinical symptoms associated with femoroacetabular impingement syndrome yet the effects of hip arthroscopy on gait mechanics and cartilage health are not well understood.

METHODS

Ten femoroacetabular impingement syndrome patients and 10 matched asymptomatic controls underwent gait analysis consisting of three-dimensional hip joint kinematics and kinetics. Femoroacetabular impingement syndrome patients underwent gait analysis and quantitative magnetic resonance imaging of the surgical hip joint before and seven months post-surgery. Patient reported outcomes were obtained from all study participants and were used to quantify hip joint pain, function and quality of life.

FINDINGS

Prior to surgery, femoroacetabular impingement syndrome patients demonstrated hip joint kinematics or kinetics as the control group. After surgery, femoroacetabular impingement syndrome patients exhibited improved patient reported outcomes, similar hip joint kinematic patterns, increased hip flexion and decreased hip extension moment impulses within the surgical limb. The femoroacetabular impingement syndrome patients that ambulated with increased HFMI post-surgery demonstrated a decrease in femoral cartilage T1ρ and T2 values.

INTERPRETATION

Femoroacetabular impingement syndrome patients exhibited improved clinical symptoms yet ambulated with altered sagittal plane hip joint loading after hip arthroscopy. Increased hip flexion moment impulse post-surgery was associated with improved cartilage health within the surgical limb. These study findings suggest that sagittal plane hip joint loading at short-term follow-up after hip arthroscopy is associated with cartilage health and may be an important biomechanical parameter in post-operative rehabilitation programs.

High prevalence of hip and groin problems in professional ice hockey players, regardless of playing position

PURPOSE

The prevalence of hip and groin problems in professional male ice hockey is unknown and suspected to differ between playing positions. The purpose of this study was to explore potential differences in the seasonal prevalence of hip and groin problems between playing positions in male elite ice hockey players and to explore the relationship between symptom duration and hip and groin function at the beginning of the new season.

METHODS

Male ice hockey players [n = 329 (92 goalkeepers, 93 defensemen, 144 forwards), Mean age (SD): 24 (5)] from the professional leagues in Sweden responded to an online survey. The survey assessed presence of hip and groin problems (time loss and non-time loss) and symptom duration (categorized into 0, 1-6, or > 6 weeks) in the previous season, and current self-reported hip and groin function (Copenhagen Hip and Groin Outcome Score).

RESULTS

During the previous season, 175 players (53.2%) had experienced hip and groin problems. Non time loss problems were experienced by 158 (48%) and time loss problems were experienced by 97 (29.5%) players. No significant differences between playing positions were found. Self-reported function differed significantly between players with different symptom duration and more disability was reported among players with longer symptom duration (p ≤ 0.002).

CONCLUSION

Regardless of playing position, hip and groin problems were prevalent in male ice hockey players. Players with hip and groin problems during the previous season had significantly worse hip and groin function in the beginning of the new season, and longer symptom duration was associated with more disability.

LEVEL OF EVIDENCE

III.

Standardised measurement of physical capacity in young and middle-aged active adults with hip-related pain: recommendations from the first International Hip-related Pain Research Network (IHiPRN) meeting, Zurich, 2018

Hip-related pain can significantly impact quality of life, function, work capacity, physical activity and family life. Standardised measurement methods of physical capacity of relevance to young and middle-aged active adults with hip-related pain are currently not established. The aim of this consensus paper was to provide recommendations for clinical practice and research on standardised measurement methods of physical capacity in young and middle-aged active adults with hip-related pain. Four areas of importance were identified: (1) clinical measures (range of motion, muscle strength, functional impairments), (2) laboratory-based measures (biomechanics and muscle function (muscle activity, size and adiposity)), (3) physical activity, and (4) return to sport/performance. The literature was reviewed, and a summary circulated to the working group to inform discussion at the consensus meeting. The working group developed clinical and research recommendations from the literature review, which were further discussed and modified within the working group at the consensus meeting. These recommendations were then presented to all 38 International Hip-related Pain Research Network (IHiPRN) participants for further discussion, refinement and consensus voting. Therefore, the recommendations voted on were based on a combination of current evidence and expert opinion. The consensus meeting voted on 13 recommendations, six of which were clinically orientated, and seven more research specific. We recommended that clinicians working with young and middle-aged active adults with hip-related pain assess strength using objective methods of measurement, and clinically assess performance of functional tasks, including walking and running. Physical activity should be quantified using both self-reported and objective measures, and patient expectations of recovery should be quantified prior to treatment. It was recommended that return to physical activity (including sport and occupation) be quantified, and sport-specific activities should be assessed prior to return to sport. The IHiPRN participants were uncertain regarding recommendations for range of motion assessment. Research recommendations were that the measurement properties of range of motion, strength and functional performance tests be investigated, reported and improved in both clinical and research settings. Reporting of movement-related parameters (biomechanics and muscle function) should be standardised and the relationship among movement-related parameters, symptoms, function, quality of life, and intra-articular and imaging findings should be investigated. Quantification of return to physical activity (including sport and occupational demands) is required in future research, and the return to sport continuum should be used. Future research is required to determine the best criteria for rehabilitation progression and return to physical activity following hip-related pain management.

Return to Sport Rates in Physically Active Individuals 6 Months After Arthroscopy for Femoroacetabular Impingement Syndrome

CONTEXT

Six months is the expected time frame to return to sport (RTS) after hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

OBJECTIVE

The primary aims of this study were to (1) report the RTS rate of physically active individuals 6 months after arthroscopic surgery for FAIS and (2) compare the self-reported hip function between those who were able to RTS against those who had not.

DESIGN

Cohort study.

SETTING

The Ohio State University Wexner Medical Center.

PATIENTS

A total of 42 physically active individuals scheduled for hip arthroscopy for FAIS.

MAIN OUTCOME MEASURES

Self-reported function, including preinjury and current activity levels and ability to participate in sport, were collected on 42 individuals with FAIS prior to surgery and at 6-month follow-up. Participants were allocated into 2 groups based on self-reported RTS status at 6-month follow-up. Separate 2-way analyses of variance were used to test the interaction of groups (those who did/did not RTS). Main effects were reported in the absence of statistically significant interactions (P ≤ .05).

RESULTS

Altogether, 28 of 42 participants (66%) returned for 6-month follow-up; 5 of the 14 participants (35.7%) lost to follow-up underwent contralateral hip surgery within the study time frame. At the 6-month follow-up, 16 of the remaining 28 participants (57.1%) reported that they had returned to sport, 5 of whom returned at their prior level of participation. There was no statistically significant interaction of group and time for either hip outcome score subscale (P ≥ .20). Self-reported hip function improved over time, regardless of group (P ≤ .001). Participants in the yRTS group demonstrated higher hip outcome score-sport scores than did the nRTS group, regardless of time (P = .04).

CONCLUSIONS

Though just over half of participants returned to sport 6 months after hip arthroscopy for FAIS, only 18% returned to their previous level of sports participation. Participants who returned to sport reported better function than those who did not, but self-reported hip function improved over time regardless of group. The most commonly reported reasons for not returning to sport were weakness (69.6%), fear (65.2%), and pain (56.5%).

Reliability of hip range of motion measurement among experienced arthroscopic hip preservation surgeons

The aim of this study was to determine (i) the reliability of hip range of motion measurement among experienced arthroscopic hip preservation surgeons and (ii) the magnitude of hip flexion change with posterior pelvic tilt. Five experienced arthroscopic hip preservation surgeons (5–18 years of hip surgery experience) performed passive hip range of motion (internal and external rotation), flexion (contralateral hip extended) and flexion with posterior pelvic tilt (contralateral hip maximally flexed) on five young healthy asymptomatic volunteers (three males, two females; 34.4 ± 10.7 years of age). Motion was measured via digital photography and goniometry. Inter-observer reliability was calculated via two-way mixed, single measures, intra-class correlation coefficient. Paired t-test was utilized to compare hip flexion (with contralateral hip extended) to hip flexion with posterior pelvic tilt (with contralateral hip in forced flexion). The reliabilities of measurements of hip flexion with posterior pelvic tilt and external rotation were excellent, that of hip flexion was fair, and that of hip internal rotation was poor. The magnitude of hip flexion increase with posterior pelvic tilt was 17.0° ± 3.0° (P < 0.001). The reliability of hip range of motion measurement by five experienced arthroscopic hip preservation surgeons was excellent for measures of hip flexion with posterior pelvic tilt and external rotation. Contralateral maximal hip flexion significantly increased ipsilateral hip flexion (approximately 17°).

Level of Evidence: Diagnostic, level III (without consistently applied reference standard)

Evaluation of Osseous Morphology of the Hip Using Zero Echo Time Magnetic Resonance Imaging

BACKGROUND

Femoroacetabular impingement syndrome (FAIS) is a common disorder of the hip resulting in groin pain and ultimately osteoarthritis. Radiologic assessment of FAI morphologies, which may present with overlapping radiologic features of hip dysplasia, often requires the use of computed tomography (CT) for evaluation of osseous abnormality, owing to the difficulty of direct visualization of cortical and subchondral bone with conventional magnetic resonance imaging (MRI). The use of a zero echo time (ZTE) MRI pulse sequence may obviate the need for CT by rendering bone directly from MRI.

PURPOSE/HYPOTHESIS

The purpose was to explore the application of ZTE MRI to the assessment of osseous FAI and dysplasia morphologies of the hip. It was hypothesized that angular measurements from ZTE images would show significant agreement with measurements obtained from CT images.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Thirty-eight hips from 23 patients were imaged with ZTE MRI and CT. Clinically relevant angular measurements of hip morphology were made in both modalities and compared to assess agreement. Measurements included coronal and sagittal center-edge angles, femoral neck-shaft angle, acetabular version (at 1-, 2-, and 3-o'clock positions), Tönnis angle, alpha angle, and modified-beta angle. Interrater agreement was assessed for a subset of 10 hips by 2 raters. Intermodal agreement was assessed on the complete cohort and a single rater.

RESULTS

Interrater agreement was demonstrated in both CT and ZTE, with intraclass correlation coefficient values ranging from 0.636 to 0.990 for ZTE and 0.747 to 0.983 for CT, indicating "good" to "excellent" agreement. Intermodal agreement was also shown to be significant, with intraclass correlation coefficients ranging from 0.618 to 0.904.

CONCLUSION

Significant agreement of angular measurements for hip morphology exists between ZTE MRI and CT imaging. ZTE MRI may be an effective method to quantitatively evaluate osseous hip morphology.

Use of Biologics as an Adjunct Therapy to Arthroscopic Surgery for the Treatment of Femoroacetabular Impingement: A Systematic Review

BACKGROUND

There has been a recent increase in the use of biologics in hip arthroscopy to assist in the management of femoroacetabular impingement (FAI).

PURPOSE

To analyze the current use of biologics for the treatment of FAI and its associated lesions.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A search of the PubMed, Medline, and EMBASE databases was performed in March 2019 with use of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The criterion for inclusion was observational, published research articles studying the therapeutic use of biologics as an adjuvant therapy during arthroscopic surgery for FAI; treatments included bone marrow aspirate concentrate, mesenchymal stem cells (MSCs), platelet-rich plasma (PRP), hyaluronic acid, growth factors, and autologous chondrocyte implantation (ACI) or autologous matrix-induced chondrogenesis (AMIC).

RESULTS

There were 9 studies that met the inclusion criteria, and a total of 674 patients were included across all studies. FAI was studied in all articles. Further, 7 studies (78%) also analyzed chondral injuries, and 3 studies also analyzed labral tears (33%). ACI or AMIC was used in 56% of studies and showed superior functional outcomes at short- and midterm follow-up versus debridement or microfracture. PRP did not improve the outcome of labral repairs at short-term follow-up.

CONCLUSION

The current literature regarding biologic adjuncts in hip arthroscopy is varied in quality, with only one level 1 study. The use of ACI/AMIC for medium-sized chondral lesions showed promising results in individual studies; however, these were of lower quality. To enable comparisons among future studies, investigators must ensure accuracy in the reporting of biologic preparations and formulations used and homogeneity in the type and severity of lesion treated.

Hip Biomechanics During a Single-Leg Squat: 5 Key Differences Between People With Femoroacetabular Impingement Syndrome and Those Without Hip Pain

BACKGROUND

The hip joint biomechanics of people with femoroacetabular impingement (FAI) syndrome are different from those of healthy people during a double-leg squat. However, information on biomechanics during a single-leg squat is limited.

OBJECTIVES

To compare hip joint biomechanics between people with FAI syndrome and people without hip pain during double-leg and single-leg squats.

METHODS

Fourteen people with FAI syndrome (cam, n = 7; pincer, n = 1; mixed, n = 6) and 14 people without hip pain participated in this cross-sectional, case-control, laboratory-based study. Three-dimensional biomechanics data were collected while all participants performed a double-leg and a single-leg squat. Two-way mixed-model analyses of variance were used to assess group-by-task interactions for hip joint angles, thigh and pelvis segment angles, hip joint internal moments, and squat performance variables. Post hoc analyses for all variables with a significant group-by-task interaction were performed to identify between-group differences for each task.

RESULTS

There were significant group-by-task interactions for peak hip joint (P = .014, η² = 0.211) and thigh segment (P = .009, η² = 0.233) adduction angles, and for peak hip joint abduction (P = .002, η² = 0.308) and extension (P = .016, η² = 0.203) internal moments. There were no significant group-by-task interactions for squat performance variables.

CONCLUSION

Biomechanical differences at the hip between people with FAI syndrome and those without hip pain were exaggerated during a single-leg squat compared to a double-leg squat task.

LEVEL OF EVIDENCE

Diagnosis, level 4. J Orthop Sports Phys Ther 2019;49(12):908-916. Epub 23 Jul 2019. doi:10.2519/jospt.2019.8356.

Functional and Clinical Outcomes of Patients Undergoing Revision Hip Arthroscopy With Borderline Hip Dysplasia at 2-Year Follow-up

PURPOSE

To compare outcomes of borderline hip dysplasia (BHD) patients undergoing revision hip arthroscopy with 1) patients with BHD undergoing primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and 2) patients without BHD undergoing revision hip arthroscopy for FAIS.

METHODS

A retrospective cohort study was performed to identify patients who underwent arthroscopy from January 2012 to January 2016 by a single fellowship-trained surgeon, including a 2-year follow-up. Patient demographics, comorbid medical conditions, and preoperative outcome scores were compared between patients with BHD (lateral center-edge angle 18° to 25°) who had revision hip arthroscopy to patients with BHD undergoing primary arthroscopy and patients without BHD (lateral center-edge angle >25°) undergoing revision arthroscopy. Cohorts were matched 2:1 by age and body mass index. Multivariate regressions were used to compare Hip Outcome Score, Activities of Daily Living subscale (HOS-ADL) and Sports subscale (HOS-SS) scores and modified Harris Hip Score (mHHS) between the cohorts at 2-year follow-up. Binomial regression analysis was used to determine predictors of achieving minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS).

RESULTS

There was no statistical difference in age and BMI between the BHD revision (29.1 ± 8.8 years; 25.5 ± 3.58 kg/m²), BHD nonrevision (28.9 ± 8.5 years; 24.6 ± 3.1 kg/m²), and non-BHD revision (29.15 ± 8.6 years; 25.01 ± 3.2 kg/m²) cohorts. There were no statistically significant differences in 2-year clinical outcomes between BHD revision patients and either BHD primary or non-BHD revision patient groups, but BHD revision patients were significantly less likely to achieve PASS for HOS-SS compared with BHD primary and non-BHD revision groups (P = .047 and P = .031, respectively).

CONCLUSION

Surgeons should exercise caution when indicating patients for revision hip arthroscopy with BHD. Although the current study lacks statistical power, the available data suggest that patients undergoing revision surgery with BHD may still experience clinical improvement but be less likely to achieve PASS metrics for several patient-reported outcomes at 2-year follow up.

LEVEL OF EVIDENCE

III, case-control study.

Single Table Concomitant Post-Less Hip Arthroscopy Combined with Periacetabular Osteotomy for Hip Dysplasia

It has been well established that both arthroscopic and open hip preservation techniques can result in improved patient outcomes and interrupt the natural history of hip disease. Traditionally, hip arthroscopy has been used to address central and peripheral compartment disease consisting of labral tears, impingement morphology and cartilage pathology. The periacetabular osteotomy has been the most used treatment for hip instability caused by inadequate acetabular coverage of the femoral head or dysplasia. With failures of periacetabular osteotomy linked to postoperative impingement and the high incidence of intra-articular pathology in the dysplastic hip, there has been a great interest in combing hip arthroscopy with the periacetabular osteotomy. Here, we describe a technique for a single table, single drape, postless combined hip arthroscopy, and periacetabular osteotomy.

Is There an Association Between Preoperative Expectations and Patient-Reported Outcome After Hip Arthroscopy for Femoroacetabular Impingement Syndrome?

PURPOSE

To determine the relationship between preoperative patient expectation and postoperative satisfaction and overall patient-reported outcome (PRO) of patients undergoing hip arthroscopy for femoroacetabular impingement syndrome.

METHODS

Patients who underwent hip arthroscopy for femoroacetabular impingement syndrome completed the validated Hip Preservation Surgery Expectations Survey (21 questions; 0-100 range), as well as multiple PROs before surgery. High expectation was defined as an expectation score greater than 1 standard deviation above the mean. Patients with osteoarthritis, dysplasia, and those having undergone previous hip surgery were excluded. At 1 year postoperatively, patient visual analog scale (VAS) satisfaction, VAS pain, and PROs were assessed. Univariable and multivariate analyses were performed.

RESULTS

One-hundred fifty-three subjects (mean age 34.4 ± 12.6 years, female: 114 [71.3%], body mass index: 25.9 ± 5.3 kg/m²) participated. The mean expectation score was 84.5 ± 12.3. Significant correlations between high expectation scores (>96.7) and achieving the minimal clinical important difference (MCID) for modified Harris Hip Score (mHHS; r = 0.339; P = .043) and patient acceptable symptomatic state (PASS) for Hip Outcome Score-Activities of Daily Living Subscale (HOS-ADL; r = 0.207; P = .032) were observed. There were no significant correlations between high expectation scores and preoperative or postoperative PROs or patient satisfaction scores. χ² analysis demonstrated patients with greater expectations had increased rates of reaching MCID mHHS (92.3% vs 74.7%; P = .08), PASS mHHS (85.7% vs 69.7%; P = .046), and PASS HOS-ADL (93.8% vs 67.4%; P = .031).

CONCLUSIONS

High preoperative expectation is associated with increased rates of MCID/PASS achievement on mHHS and increased rate of PASS achievement on HOS-ADL. Preoperative expectations did not have an impact on Hip Outcome Score-Sports Subscale; however, patients with high preoperative expectations also have a high baseline Hip Outcome Score-Sports Subscale. In addition, preoperative expectations are not associated with postoperative VAS satisfaction scores.

LEVEL OF EVIDENCE

III; non-randomized cohort, therapeutic.

Physiotherapist-led treatment for young to middle-aged active adults with hip-related pain: consensus recommendations from the International Hip-related Pain Research Network, Zurich 2018

The 1st International Hip-related Pain Research Network meeting discussed four prioritised themes concerning hip-related pain in young to middle-aged adults: (1) diagnosis and classification of hip-related pain; (2) patient-reported outcome measures for hip-related pain; (3) measurement of physical capacity for hip-related pain; (4) physiotherapist-led treatment for hip-related pain. Thirty-eight expert researchers and clinicians working in the field of hip-related pain attended the meeting. This manuscript relates to the theme of physiotherapist-led treatments for hip-related pain. A systematic review on the efficacy of physiotherapist-led interventions for hip-related pain (published separately) was conducted and found that strong evidence for physiotherapist-led treatments was lacking. Prior to the meeting, draft consensus recommendations for consideration in the meeting were also developed based on the systematic review. The draft consensus recommendations were presented to all of the meeting participants via email, at least 1 week prior to the meeting. At the meeting, these recommendations were discussed, revised and voted on. Six recommendations for clinical practice and five recommendations for research were included and all gained consensus. Recommendations for clinical practice were that (i) Exercise-based treatments are recommended for people with hip-related pain. (ii) Exercise-based treatment should be at least 3 months duration. (iii) Physiotherapist-led rehabilitation after hip surgery should be undertaken. (iv) Patient-reported outcome measures, measures of physical impairment and measures of psychosocial factors should be used to monitor response to treatment. (v) Physical activity (that may include sport) is recommended for people with hip-related pain. (vi) Clinicians should discuss patient expectations, use shared-decision making and provide education. Recommendations for research were (i) Reporting of exercise programmes: Exercise descriptors such as load magnitude, number of repetitions and sets, duration of whole programme, duration of contractile element of exercise, duration of one repetition, time under tension, rest between repetitions, range of motion through which the exercise is performed, and rest between exercise sessions should be reported. (ii) Research should investigate the optimal frequency, intensity, time, type, volume and progression of exercise therapy. (iii) Research should examine the effect of patient education in people with hip-related pain. (iv) Research should investigate the effect of other treatments used in people with hip-related pain (for example: manual therapy, medications, injections). (v) Research should examine the impact of comorbidities and social determinants on treatment effectiveness in people with hip-related pain. Clinicians and researchers working with young to middle-aged active adults with hip-related pain may use these consensus recommendations to guide, develop, test and implement individualised, evidence-based physiotherapist-led rehabilitation programmes.

THE ROLE of a BIKE FIT in CYCLISTS with HIP PAIN. A CLINICAL COMMENTARY

Hip pathology is common amongst athletes and the general population. The mechanics of cycling have the potential to exacerbate symptomatic hip pathology and progress articular pathology in patients with morphologic risk factors such as femoroacetabular impingement. A professional fit of the bicycle to the individual which aims to optimize hip joint function can allow patients with hip pathology to exercise in comfort when alternative high impact exercise such as running may not be possible. Conversely improper fit of the bicycle can lead to hip symptoms in otherwise healthy individuals who present with risk factors for hip pain. Accordingly a bike fit can form part of the overall management strategy in a cyclist with hip symptoms. The purpose of this clinical commentary is to discuss hip pathomechanics with respect to cycling, bicycle fitting methodology and the options available to a physical therapist to optimize hip mechanics during the pedaling action.