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

Biomechanical measures of clinician-defined unsteadiness during a forward stepdown task in individuals post-arthroscopy for femoroacetabular impingement syndrome

BACKGROUND

Patients with femoroacetabular impingement syndrome can present with aberrant movement patterns including unsteady balance. Balance training is included in rehabilitation after hip arthroscopy and may improve quality of movement; however, specific biomechanical measures associated with clinician-defined balance impairments are unknown. We aimed to understand these associations as they may inform targeted rehabilitative interventions.

METHODS

The forward stepdown is a clinical test used to evaluate movement quality, including balance. 23 individuals at least one-year post-arthroscopy for femoroacetabular impingement syndrome and 15 healthy comparisons performed the forward stepdown, recorded by 3-dimensional motion capture and 2-dimensional video. Three physical therapists graded the 2-dimensional video for steadiness. Two-way analyses of variance were used to evaluate the interaction of group (post-arthroscopy/healthy comparison) by steadiness (steady/unsteady), for center of pressure medial-lateral excursion, center of pressure path length, and lateral trunk, pelvis, and lower extremity joint excursions.

FINDINGS

Six (26.1%) participants post-arthroscopy and five (33.3%) healthy comparisons were categorized as unsteady. The odds of being categorized as unsteady were not greater for participants post-arthroscopy (P = 0.72). There were no significant interactions; however, participants with clinician-defined unsteady balance, regardless of group, had significantly greater frontal plane trunk excursion, greater hip excursion, and greater center of pressure path length than those with steady balance (P ≤ 0.006).

INTERPRETATION

The odds of being categorized as unsteady were not greater for individuals post-arthroscopy for femoroacetabular impingement syndrome. Clinician-defined unsteadiness was associated with greater frontal plane trunk and hip motion which may be rehabilitation targets to improve balance during a dynamic single-leg task.

Treatment decisions after interdisciplinary evaluation for nonarthritic hip pain: A randomized controlled trial

BACKGROUND

Physical therapy and hip arthroscopy are two viable treatment options for patients with nonarthritic hip pain (NAHP); however, patients may experience considerable decisional conflict when making a treatment decision. Interdisciplinary evaluation with a physical therapist and surgeon may better inform the decision-making process and reduce decisional conflict.

OBJECTIVE

To identify the extent to which an interdisciplinary evaluation between a surgeon, physical therapist, and patient influences treatment plans and decisional conflict of persons with NAHP.

DESIGN

Randomized controlled trial.

SETTING

Hip preservation clinic.

PARTICIPANTS

Adults with primary NAHP.

INTERVENTIONS

Participants were randomized to receive a standard (surgeon) or interdisciplinary (surgeon+physical therapist) evaluation. Surgeon evaluations included patient interview, strength and range-of-motion examination, palpation, gross motor observation, and special testing. Interdisciplinary evaluations started with the surgeon evaluation, then a physical therapist evaluated movement impairments during sitting, sit-to-stand, standing, single-leg stance, single-leg squat, and walking. All evaluations concluded with treatment planning with the respective provider(s).

OUTCOME MEASURES

Treatment plan and decisional conflict were collected pre- and postevaluation. Inclusion of physical therapy in participants' postevaluation treatment plans and postevaluation decisional conflict were compared between groups using chi-square tests and Mann-Whitney U tests, respectively.

RESULTS

Seventy-eight participants (39 in each group) met all eligibility criteria and were included in all analyses. Sixty-six percent of participants who received an interdisciplinary evaluation included physical therapy in their postevaluation treatment plan, compared to 48% of participants who received a standard evaluation (p = .10). Participants who received an interdisciplinary evaluation reported 6.3 points lower decisional conflict regarding their postevaluation plan (100-point scale; p = .04). The interdisciplinary and standard groups reduced decisional conflict on average 24.8 ± 18.9 and 23.6 ± 14.6 points, respectively.

CONCLUSIONS

Adding a physical therapist to a surgical clinic increased interest in physical therapy treatment, but this increase was not statistically significant. The interdisciplinary group displayed lower postevaluation decisional conflict; however, both groups displayed similar reductions in decisional conflict from pre- to postevaluation. This study also demonstrated the feasibility of an interdisciplinary evaluation in a hip preservation clinic.

Knee and hip dynamic muscle strength in individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy: A case-control study

Background The primary aim of this study was to compare knee and hip dynamic muscle strength of individuals with femoroacetabular impingement (FAI) syndrome scheduled for hip arthroscopy with healthy controls. Our secondary aim was to compare hip and knee muscle strength between male and female patients with FAI syndrome. Methods One hundred and thirty-four individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy and 134 healthy controls matched for sex and age (within 5 years range) underwent an isokinetic assessment of knee extension and flexion and hip abduction, adduction, external rotation and internal rotation dynamic muscle strength. Two MANOVAs were conducted to compare isokinetic peak torque and total work between groups and sexes. Findings Individuals with femoroacetabular impingement syndrome demonstrated lower values of all variables representing knee and hip isokinetic peak torque and total work measures when compared to healthy controls, with differences ranging from 0.09 Nm/kg (95%CI: 0.06-0.12 Nm/kg) to 0.64 Nm/kg (95%CI: 0.49-0.79 Nm/kg). Female participants from both FAI syndrome and control group showed less knee and hip muscle strength compared to male participants. There was no significant interaction between group and sex regarding knee or hip isokinetic peak torque and total work (p > 0.05). Interpretation Individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy present impairments in knee or hip dynamic muscle strength when compared to controls. Female participants present less knee and hip muscular strength compared to male participants, these between-sex differences are similar for both FAI syndrome and control group participants.

Cam Morphology Is Associated With Increased Femoral Version: Findings From a Collection of 1,321 Cadaveric Femurs

BACKGROUND

To evaluate the relationship between femoral version (FV) and α angle (AA) in a large osteological collection of human femurs.

METHODS

The University of Iowa-Stanford osteological collection was used to evaluate the research aims. To measure FV and AA, axial photographs of the proximal femurs were taken, referenced from the posterior condylar axis. FV and AA measurements were obtained using ImageJ software, and the relationship between FV and AA was assessed with repeated-measures analysis of variance and generalized linear models. A P value of <.05 was considered statistically significant.

RESULTS

A total of 1321 cadaveric femurs (666 left and 655 right) in 721 cadavers were examined. The average AA for all femurs was 47.8° ± 10.9°, and the average FV for all femurs was 8.53° ± 8.09°. Overall, 191 femurs (14.5%) exhibited cam morphology (AA ≥ 60°). Of the 721 cadavers, 600 had both femurs available for side-to-side comparison. The average FV of femurs with cam morphology was significantly higher than that of femurs without cam morphology (11.70° ± 8.82° vs. 7.99° ± 8.82°, P < .001). Linear regression analysis demonstrated that increased AA was significantly correlated with increased FV (β ± standard error of the mean = 0.21 ± 0.02, P < .0001).

CONCLUSION

In a large osteological collection of human femurs, a significant positive relationship between AA and increasing FV was identified.

CLINICAL RELEVANCE

FAI and hip impingement morphology are more complex than cam or pincer morphology. Cam morphology with high femoral anteversion may allow for normal or near-normal hip mechanics without impingement, and this may partially explain the high rates of asymptomatic cam-type femoroacetabular impingement (FAI) morphology in active and general populations. Given the multiple morphological factors implicated in the development of FAI syndrome, these findings warrant further investigation.

[Epidemiology, prevention and early detection of femoroacetabular impingement syndrome (FAIS)]

During the last two decades femoroacetabular impingement syndrome (FAIS) has gained importance and is one of the main causes of hip pain in young adults. FAIS is a motion-related clinical pathology of the hip that represents symptomatic contact between the proximal femur and the acetabulum. Symptoms, clinical signs, and imaging findings must be present to diagnose FAIS. Especially the development of the cam-FAIS seems to be associated with an overuse of the growth plate during adolescence. Here an approach may be found for the prevention of the development of FAIS. Sufficient evidence through high-quality long-term results is yet lacking.

Dynamic Assessment of Femoroacetabular Impingement Syndrome Hips

PURPOSE

The purpose of our study was to compare lower extremity rotational kinematics and kinetics (angles, torques, and powers) and hip muscle electromyography (EMG) activity between cam-type femoroacetabular impingement syndrome (FAIS) and age- and sex-matched controls during walking, fast walking, stair ascent, stair descent, and sit-to-stand.

METHODS

This study included 10 males with unilateral FAIS and 10 control males with no FAIS. We measured kinematics, kinetics, and electromyographic signals during stair ascent/descent, sit-to-stand, self-selected walk, and fast walk. Peak signal differences between groups were compared with independent t-tests with statistical significance when P < .05.

RESULTS

FAIS hips showed significant differences compared to controls, including increased hip flexion during walking (+4.9°, P = .048) and stair ascent (+7.8°, P =.003); diminished trunk rotation during stair ascent (-3.4°; P = .015), increased knee flexion during self-selected walking (+5.1°, P = .009), stair ascent (+7.4°, P = .001), and descent (+5.3°, P = .038); and increased knee valgus during fast walking (+4.7°, P = .038). gMed and MedHam showed significantly decreased activation in FAIS during walking (gMed: -12.9%, P = .002; MedHam: -7.4%, P = .028) and stair ascent (gMed: -16.7%, P = .036; MedHam: -13.0%, P = .041); decreased gMed activation during sit-to-stand (-8.8%, P = .004) and decreased MedHam activation during stair descent (-8.0%, P = .039).

CONCLUSIONS

Three-dimensional motion analysis and EMG evaluation of functional kinematics and kinetics in subjects with symptomatic unilateral cam-type FAIS across a spectrum of provocative tasks demonstrated significant differences compared to controls in hip flexion, trunk rotation, knee flexion, and valgus. FAIS hips had significantly decreased gMed and MedHam activity. These findings may explain altered torso-pelvic, hip, and knee mechanics in FAIS patients and suggest that evaluation of FAIS should include the patient's hip, knee, and torso-pelvic relationships and muscle function.

CLINICAL RELEVANCE

The clinical and functional manifestation of FAIS hip pathomechanics is not entirely understood, and previous literature to date has not clearly described the alterations in gait and functional movements seen in patients with cam-type FAIS. The current study used 3D motion analysis and EMG evaluation of functional kinematics and kinetics to identify a number of differences between FAIS and control hips, which help us better understand the lower extremity kinematics and kinetics and muscle activation in FAIS.

Correlation between the range of rotation of the hip and the radiographic signs of cam and pincer morphology in femoroacetabular impingement syndrome

Objective

To determine whether hip rotation correlates with the radiographic signs of cam or pincer deformity after hip arthroscopy in patients with femoroacetabular impingement syndrome.

Materials and Methods

This was a single-center retrospective study of data collected between 2014 and 2017. The study sample included 65 patients between 18 and 55 years of age who underwent hip arthroscopy for the treatment of unilateral femoroacetabular impingement. The following data were collected for the periods prior to and six months after surgery range of medial and lateral rotation of the hip; measures on anteroposterior X-rays of the pelvis obtained in the standing position and on ateral X-rays in the Ducroquet profile view; and score on the 33-item International Hip Outcome Tool.

Results

Mean preoperative and postoperative values were as follows: 19.26 ± 10.39° and 30.95 ± 3.52°, respectively, for medial rotation of the hip (p < 0.001); 73.85 ± 6.62° and 68.12 ± 5.04°, respectively, for the anteroposterior alpha angle (p < 0.001); 56.97 ± 6.09° and 50.61 ± 5.39°, respectively, for the lateral alpha angle (p < 0.001); and 0.17 ± 0.11 and 0.07 ± 0.08, respectively, for the acetabular retroversion index (p < 0.001). The crossover sign was identified in 75.4% of the patients before surgery and in 44.6% after (p < 0.001). Although there was an increase in the range of hip rotation and an improvement in radiographic parameters after arthroscopy, we detected no direct correlation between the two.

Conclusion

Hip arthroscopy can improve medial rotation of the hip, as well as reducing cam and pincer deformities, in patients with femoroacetabular impingement syndrome. However, those findings do not appear to be directly correlated.

Relationship between hip muscle strength and hip biomechanics during running in people with femoroacetabular impingement syndrome

BACKGROUND

Hip muscle weakness and altered hip biomechanics during walking are often observed in people with femoroacetabular impingement syndrome, although little is known about biomechanics during higher impact tasks. The aim of our study was to explore relationships between hip muscle strength and hip biomechanics during running in people with femoroacetabular impingement syndrome, including exploring sex as an effect-modifier of this relationship.

METHODS

Forty-two adults with unilateral femoroacetabular impingement syndrome (20 females; age 18-50 years; alpha angle ≥60°) completed assessments of hip muscle strength and hip biomechanics during running. Strength was assessed using a hand-held dynamometer for the hip flexors, extensors, abductors, adductors, internal rotators, and external rotators. Hip biomechanics were assessed during overground running (3-3.5 m/s) using three-dimensional motion capture and a force plate. Linear models assessed the relationships between hip strength and hip biomechanics of the symptomatic limb, controlling for body mass and running velocity along with an interaction term (strength*sex).

FINDINGS

A significant negative relationship was observed between hip external rotator strength and hip frontal plane range of motion (i.e., excursion), independent of sex (estimate = -0.039, 95%CI -0.071 to -0.008, P = 0.02). Four sex-specific interactions were observed, with a significant positive relationship between hip external rotator strength and peak hip extension moment in women (estimate = -0.413, 95%CI -0.713 to -0.114, P = 0.01) but not in men.

INTERPRETATION

We found significant relationships between hip external rotator strength and stance phase running biomechanics, providing further understanding on two impaired physical measures that may inform exercise-based management strategies in femoroacetabular impingement syndrome.

Correlação entre intensidade da dor e incapacidade com as lesões intra-articulares em pacientes com síndrome do impacto femoroacetabular

Objective  To correlate radiographic alterations and lesions in intra-articular structures of the acetabulum with the intensity of pain and disability of patients diagnosed with femoroacetabular impingement syndrome.

Methods  A retrospective analysis of the preoperative data of 182 patients (190 hips) was performed. Clinical variables such as age, gender, the practice of physical activity, and radiographic variables, such as the Wiberg and alpha angles, were evaluated. Through an intraoperative video, the extent of the chondral and labial lesions was evaluated considering the clock-face method, the degree of joint involvement by the Outerbridge classification, and the presence of wave lesions. The variables were analyzed by linear regression, with the intensity of the pain assessed by the Visual Analog Scale (VAS), and functional disability measured by the Modified Harris Hip Score (mHHS).

Results  The mean age of the patients was of 38.5 ±  9.6 years, the mean intensity of the pain was of 7.8 ± 1.6, and the mean mHHS score was of 56.3 ±  12.7. In total, 61% of the sample were classified as Outerbridge III or IV, and 12.6% had wave lesions. There was a correlation between the male gender (r = 0.497) and lower intensity of the pain, and a correlation of age (r = -0.27), the male gender (r = 8.419) and physical activity with higher functional scores on the mHHS (r = 4.729).

Conclusion  There was no correlation of the radiographic and arthroscopic parameters of the present study and the intensity of pain and the disability of the patients. The male gender is related to lower intensity of pain, and higher functional ability is related to the male gender, lower age, and the practice of physical activity.

Level of Evidence IV.

Functional Outcomes of Arthroscopic Acetabular Labral Repair with and without Bone Marrow Aspirate Concentrate

BACKGROUND

Osteoarthritis (OA) of the hip is a debilitating condition associated with inferior outcomes in patients undergoing hip arthroscopy. To provide symptom relief and improve outcomes in these patients, bone marrow aspirate concentrate (BMAC) has been applied as an adjuvant therapy with the hope of halting progression of cartilage damage. The current study examined the clinical efficacy of BMAC application in patients undergoing arthroscopic acetabular labral repair by comparing patient-reported outcome measures (PROMs) between groups with and without BMAC application.

METHODS

Patients who received BMAC during arthroscopic acetabular labral repair from December 2016 to June 2019 were compared with a control cohort that underwent the same procedure but did not receive BMAC from November 2013 to November 2016. Patients in both cohorts were asked to prospectively complete PROMs prior to surgery and at 3, 6, 12, and 24-month follow-up intervals; those who completed the PROMs at enrollment and the 12-month follow-up were included in the study. An a priori subgroup analysis was performed among patients with moderate cartilage damage (Outerbridge grade 2 or 3). The analyses were adjusted for any differences in baseline factors between groups.

RESULTS

Sixty-two patients with BMAC application were compared with 62 control patients without BMAC application. When compared with the no-BMAC cohort, the BMAC cohort did not report significantly different mean International Hip Outcome Tool-33 (iHOT-33) scores at any postoperative time point. However, when patients with moderate cartilage damage were compared across groups, the BMAC cohort reported significantly greater mean (95% confidence interval) scores than the no-BMAC cohort at the 12-month (78.6 [72.4 to 84.8] versus 69.2 [63.3 to 75.2]; p = 0.035) and 24-month (82.5 [73.4 to 91.6] versus 69.5 [62.1 to 76.8]; p = 0.030) follow-up. Similarly, these patients reported greater score improvements at 12 months (37.3 [30.3 to 44.3] versus 25.4 [18.7 to 32.0]; p = 0.017) and 24 months (39.6 [30.4 to 48.7] versus 26.4 [19.1 to 33.8]; p = 0.029).

CONCLUSIONS

Patients with moderate cartilage injury undergoing arthroscopic acetabular labral repair with BMAC application reported significantly greater functional improvements when compared with similar patients without BMAC application.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Application of the 4-Element Movement System Model to Sports Physical Therapy Practice and Education

The 4-Element Movement System Model describes primary elements (motion, force, motor control, and energy) essential to the performance of all movements. The model provides a framework or scaffolding which allows for consistent processes to be used in examination and intervention decisions. The process starts with task identification followed by a systematic observation of control, amount, speed, symmetry, and symptoms during movement. Testable hypotheses are generated from the observations which inform the examination and the interventions. This commentary describes the use of the 4-Element Movement System Model in entry level and post-graduate residency educational programs and in clinical care with three common sports-related diagnoses.

LEVEL OF EVIDENCE

5.

Beyond the Basics of Athletic Hip Evaluation

Abstract

There is a growing trend in the world of orthopedics and sports medicine revolving around the nonarthritic hip. The incidence of hip arthroscopy has exponentially grown in the past decade and despite the importance of the recognition of these hip pathologies as contributors to pain and dysfunction, there is an ever-increasing rate of “failed” procedures emerging in the literature. The etiology of femoroacetabular impingement (FAI) syndrome and associated pathologies of the hip are now better understood. With this understanding there appears a tendency to point a finger at the hip joint without consideration for the involvement of the surrounding joints or extraarticular structures. Because of the nature of the morphological condition of FAI and the high incidence of a gradual progression of pain and impairments over time, as opposed to an acute injury, there is a need for a more robust assessment of the hip. The purpose of this commentary is to discuss the importance of a combined traditional orthopedic exam, imaging, and movement assessment in diagnosis and treatment recommendations in those with nonarthritic hip pain. It is our belief that this combined model can assist in identifying movement dysfunction that may lead to poor surgical outcomes and developing improved nonoperative or preoperative care pathways.

Level of evidence

Level V.

The Erector Spinae Plane Block in the Setting of Hip Arthroscopy: A Prospective Randomized Controlled Clinical Trial

PURPOSE

To investigate whether the use of an erector spinae plane block (ESPB) would reduce perioperative pain after arthroscopic therapy for femoroacetabular impingement syndrome (FAIS) and to examine the amount of additional opioids and postoperative nausea and vomiting (PONV).

METHODS

From October 2019 to October 2020, 68 patients undergoing arthroscopic therapy for FAIS were randomly allocated into 2 groups. The first group received an ultrasound-guided ESPB preoperatively with 30 mL of 0.375% ropivacaine and standard postoperative oral medication. The second group received a sham block preoperatively with 30 mL of 0.9% saline and standard postoperative oral medication. The primary endpoint was pain scores (numeric pain score out of 10) during the first 24 hours postoperatively. Secondary outcomes were opioid consumption during the first 24 hours (converted to morphine equivalents) and the incidence of PONV. Demographic and clinical characteristics were recorded for all patients. Categorial data were compared with chi-squared and Fisher's exact tests. Continuous data were compared with 2-sided t tests and Wilcoxon rank-sum tests.

RESULTS

Sixty-eight subjects consented and were successfully randomized. Reported postoperative pain was significantly lower in the ESPB group than in the control group during the first 24 hours. The opioid amount (P = .865) and postoperative nausea (P = .642) did not differ significantly between groups. No associated complications such as falls, hematomas, or muscular weakness occurred in either group.

CONCLUSION

This study demonstrates that ESPB significantly decreases pain in the first 24 hours after arthroscopic therapy for FAIS. However, there was no evidence of lower opioid consumption compared with the control group. Overall, a low and comparable rate of PONV was present. Therefore, the ESPB seems to complement a multimodal approach to perioperative pain management in hip arthroscopy.

LEVEL OF EVIDENCE

1, randomized controlled trial.

Survivorship Rate and Clinical Outcomes 10 Years After Arthroscopic Correction of Symptomatic Femoroacetabular Impingement

BACKGROUND

Femoroacetabular impingement (FAI) is a common mechanical hip condition, prevalent in both the athletic and the general population. Surgical intervention is an effective treatment option that improves both symptoms and function in short- to medium-term follow-up. Few studies within the literature have reported the longer-term success of arthroscopic surgery.

PURPOSE

The aim of this study was to quantify the 10-year survivorship and clinical outcome for patients treated arthroscopically for symptomatic FAI.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients from our hip registry (n = 119) completed patient-reported outcome measures (PROMs) including the modified Harris Hip Score (mHHS), University of California Los Angeles (UCLA) activity scale, 36-Item Short Form Health Survey (SF-36), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at a minimum of 10 years after arthroscopy (range, 10-12 years). Results were compared with baseline scores using the Wilcoxon signed rank test. The associations among several prognostic factors, which included age, sex, Tönnis grade, and labral treatment, and subsequent conversion to total hip replacement (THR) or repeat hip arthroscopy (RHA) were analyzed using the chi-square analysis. Relationships between range of motion and radiological findings with clinical outcome were also examined using Pearson correlation analysis. Minimal clinically important difference (MCID) was calculated using a distribution method (0.5 standard deviation of the change score), and substantial clinical benefit (SCB) was determined using an anchor method. Finally, receiver operating characteristic curves with subsequent Youden index were used to determine cutoffs for PROMs, which equated to a Patient Acceptable Symptom State (PASS).

RESULTS

A total of 8.4% of cases required conversion to THR, and 5.9% required RHA. Statistically significant improvements in mHHS, SF-36, and WOMAC scores, with high satisfaction (90%), were observed 10 years after surgery. No significant change was seen in activity level (UCLA score) despite patients being 10 years older. A high percentage of patients achieved MCID for mHHS (88%), SF-36 (84%), and WOMAC (60%). The majority of patients also achieved PASS (62% for mHHS, 85% for UCLA, 78% for SF-36, and 84% for WOMAC) and SCB (74% for mHHS, 58% for UCLA, 52% for SF-36, and 56% for WOMAC).

CONCLUSION

Arthroscopic intervention is a safe and viable treatment option for patients with symptomatic FAI, and patients can expect long-term improvements and high satisfaction. Results indicated a high satisfaction (90%) and survivorship rate (91.6%), with excellent clinical outcome, 10 years after the initial procedure.

How does hip osteoarthritis differ from knee osteoarthritis?

Hip and knee osteoarthritis (OA) are leading causes of global disability. Most research to date has focused on the knee, with results often extrapolated to the hip, and this extends to treatment recommendations in clinical guidelines. Extrapolating results from research on knee OA may limit our understanding of disease characteristics specific to hip OA, thereby constraining development and implementation of effective treatments. This review highlights differences between hip and knee OA with respect to prevalence, prognosis, epigenetics, pathophysiology, anatomical and biomechanical factors, clinical presentation, pain and non-surgical treatment recommendations and management.

Hip joint range of motion is restricted by pain rather than mechanical impingement in individuals with femoroacetabular impingement syndrome

INTRODUCTION

Discerning whether range of motion (ROM) is restricted by morphology or other pain sources is challenging in patients with femoroacetabular impingement syndrome (FAIS). Computed tomography (CT) motion simulation provides a hypothetical ROM based on morphology. This study aimed to explore associations between ROM measured using CT motion simulation and maximum passive ROM measured clinically using three dimensional (3D) motion analysis in patients with FAIS, prior to and post arthroscopic hip surgery.

MATERIALS AND METHODS

Eight males with FAIS (in total 12 hip joints) were included in this explorative feasibility study. Participants were examined using CT according to a low-dose protocol prior to and 7-months post arthroscopic surgery. Software was used to simulate at which ROM the impingement would occur. With the hip in 90 degrees' flexion, maximum passive range of internal hip rotation, and maximum passive internal hip rotation coupled with adduction was examined clinically using 3D motion analysis pre- and postoperatively. Spearman rank correlation coefficients and linear regressions examined associations between methods.

RESULTS

Preoperatively, the correlation between maximum internal hip rotation measured using CT motion simulation and 3D motion analysis was strong (r = 0.71, p = 0.009). Linear regressions demonstrated that maximal internal rotation measured using CT motion simulation was predominantly larger than when measured using 3D motion analysis. Postoperatively, and when maximum internal rotation was coupled with adduction, no correlations were found between the two methods.

CONCLUSIONS

The hypothetical morphology restricted ROM is larger than clinically assessed pain restricted ROM, both prior to and post hip arthroscopy. These findings suggest that ROM is restricted by pain rather than mechanical, morphology-based impingement in individuals with FAIS.

Prevalence of low back pain and related disability in patients with femoroacetabular impingement syndrome

BACKGROUND

Low back pain (LBP) has been associated with worse hip function for persons with femoroacetabular impingement syndrome (FAIS). Reports are limited to surgical populations and based on the presence or absence of LBP, regardless of pain severity.

OBJECTIVES

To report the prevalence of clinically significant LBP for persons with FAIS; compare demographics, pain, and function between those with and without clinically significant LBP; and evaluate relationships between hip function and both LBP-related disability and LBP severity. We hypothesized that participants with LBP would be older, have higher body mass index (BMI), and report worse groin pain, longer symptom duration, and worse hip function. We hypothesized that worse LBP-related disability and LBP severity would be related to worse hip function.

DESIGN

Observational cross-sectional study.

SETTING

Hip preservation clinic.

PARTICIPANTS

158 persons with FAIS.

INTERVENTIONS

n/a MAIN OUTCOME MEASURE(S): Visual analog pain scales (VAS 0-100) were used to categorize participants with (≥30) and without (<30) clinically significant LBP. Age, sex, BMI, pain severity and duration, and hip function (33-item Hip Outcome Tool [iHOT33]) were compared between those with and without clinically significant LBP. Correlations were evaluated between the modified Oswestry Disability Index (ODI) and iHOT33, ODI and groin pain severity, LBP severity and iHOT33, and LBP and groin pain severity.

RESULTS

Sixty percent of participants reported clinically significant LBP (n = 95). These participants reported worse iHOT33 scores (mean difference: 10.1 points) than those without clinically significant LBP (p = .001). Worse ODI scores were associated with worse iHOT33 scores (P < .001; ρ = -0.74). Significant relationships were also observed between (1) ODI and groin pain, (2) LBP and iHOT33, and (3) LBP and groin pain, but the magnitudes of these correlations were weak (ρ ≤ 0.36).

CONCLUSIONS

Clinically significant LBP is highly prevalent in persons with FAIS and is associated with worse hip function. Worse LBP-related disability, but not LBP severity, was strongly associated with worse hip function.

Assessment and classification of peripheral pain in athletes: a scoping review protocol

Pain is often presumed to be part of the sport injury experience. The time-loss definition of injury leads to under-reported athletic pain impacting performance and quality of life. Whilst research regarding the assessment and classification of back pain in athletes is emerging, little has been reported regarding how peripheral pain is assessed and classified in research and practice. Six databases will be searched for relevant articles. Title and abstract screening followed by full-text screening will be completed by two independent reviewers. Data charting will be carried out using a modified standardised form. Descriptive results and frequencies will be reported. Pain measures identified in the studies will be mapped against the IOC Athlete Pain Framework alongside a narrative summary. Published peer-reviewed primary research studies alongside systematic reviews and clinical practice guidelines reporting the assessment or classification of pain in athletes of any age with chronic or acute peripheral pain across all study contexts in the English language on human participants from inception of the databases will be included. The results of this study are part of a body of research which will be used to inform the development of a pain assessment framework. The scoping review will be submitted for peer-reviewed journal publication and presented at sports medicine conferences. This review will inform researchers and clinicians working with athletes in pain how pain assessment and classification is currently conducted and positioned against the IOC Athlete Pain Framework.

Treatment of Full-Thickness Acetabular Chondral Flaps During Hip Arthroscopy: Bone Marrow Aspirate Concentrate Versus Microfracture

Background:

The optimal treatment strategy for patients with full-thickness chondral flaps undergoing hip arthroscopy is controversial.

Purpose:

To compare functional outcomes of patients who underwent bone marrow aspirate concentrate (BMAC) application with those of patients who underwent microfracture.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This was a retrospective case series of prospectively collected data on patients who underwent arthroscopic acetabular labral repair by 1 surgeon between June 2014 and April 2020. The inclusion criteria for this study were age ≥18 years, preoperative radiographs of the pelvis, arthroscopic acetabular labral repair, exposed subchondral bone with overlying chondral flap seen at the time of hip arthroscopy, microfracture or BMAC to address this lesion, and completed patient-reported outcome measures (PROMs) (International Hip Outcome Tool–33 [iHOT-33], Hip Outcome Score–Activities of Daily Living [HOS-ADL], Hip Outcome Score–Sports Subscale [HOS-Sport], modified Harris Hip Score [mHHS], and visual analog scale [VAS] for pain) at enrollment and 12-month follow-up. Clinical outcomes were assessed using PROM scores.

Results:

A total of 81 hips with full-thickness chondral flaps were included in this study: 50 treated with BMAC and 31 treated with microfracture. There were no significant differences between groups in age, sex, body mass index, tear size, radiographic osteoarthritis, or radiographic femoroacetabular impingement. In the BMAC cohort, all PROM scores improved significantly from preoperatively to follow-up: 41.7 to 75.6 for iHOT-33, 67.6 to 91.0 for HOS-ADL, 41.5 to 72.3 for HOS-Sport, 59.4 to 87.2 for mHHS, and 6.2 to 2.2 for VAS pain (P < .001 for all). In the microfracture cohort, the score improvements were 48.0 to 65.1 for iHOT-33 (P = .001), 80.5 to 83.3 for HOS-ADL (P = .275), 59.2 to 62.4 for HOS-Sport (P = .568), 70.4 to 78.3 for mHHS (P = .028), and 4.9 to 3.6 for VAS pain (P = .036). Regarding clinically meaningful outcomes, 77.6% of the BMAC group and 50.0% of the microfracture group met the minimal clinically important difference for iHOT-33 at the 12-month follow-up (P = .013).

Conclusion:

Patients with full-thickness chondral flaps at the time of hip arthroscopy experienced greater improvements in functional outcome scores at the 12-month follow-up when treated with BMAC as opposed to microfracture.

Rate of continued conservative management versus progression to surgery at minimum one year follow-up in patients with pre-arthritic hip pain

INTRODUCTION

Extensive literature has described surgical outcomes for pre-arthritic hip pain, but the proportion of patients who progress to surgery remains unknown.

OBJECTIVE

To determine the proportion of patients who present to a tertiary referral center for pre-arthritic hip pain and progress to surgery at minimum one year follow-up.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary care academic medical center.

PATIENTS

Thirteen to 40-year-olds who presented for initial evaluation to a conservative or surgical orthopedic specialist and were diagnosed with pre-arthritic hip pain (n=713 patients, 830 hips).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

The primary outcome was the rate of progression to surgery at minimum one year follow-up for the entire cohort. Predictors of progression to surgery were determined for the entire cohort and for radiographically defined subgroups using multiple logistic regression. Candidate predictors included baseline demographic, radiographic, clinical diagnosis, and patient-reported outcome measures.

RESULTS

In a cohort with mean age 25.4 (SD 8.1) years, 72.7% female, and mean follow-up 2.6 (range 1.0-4.8) years, 429/830 hips (51.7% [95% CI 48.2%-55.1%]) progressed to surgery. Predictors of surgical progression in the entire cohort included younger age (OR 0.95/year [95% CI 0.93-0.98]), pain duration longer than six months (OR 1.87-2.03, p≤.027), worse physical function (OR 0.96/Patient-Reported Outcomes Measurement Information System (PROMIS) point [0.92-0.99]), and a clinical diagnosis of femoroacetabular impingement (FAI) (OR 3.47 [2.05-5.89]), acetabular dysplasia (OR 2.75 [1.73-4.35]), and/or labral tear (OR 10.71 [6.98-16.47]). Radiographic dysplasia (lateral center edge angle<20⁰ ) increased the likelihood of surgery in all subgroups (OR 2.05-8.47, p≤.008). Increasing maximum α angle increased the likelihood of surgery in patients with severe cam FAI (α>63⁰ ) (OR 1.03/degree [1.00-1.06]).

CONCLUSION

Almost half of patients with pre-arthritic hip pain did not progress to surgery at minimum one year follow-up. A trial of conservative management is likely worthwhile in most patients. This article is protected by copyright. All rights reserved.

Prolonged Postoperative Opioid Use After Arthroscopic Femoroacetabular Impingement Syndrome Surgery: Predictors and Outcomes at Minimum 2-Year Follow-up

Background:

The association between prolonged postoperative opioid use on outcomes after hip preservation surgery is not known.

Purpose:

To compare minimum 2-year patient-reported outcomes (PROs) between patients who required ≥1 postoperative opioid refill after undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) versus patients who did not require a refill and to identify preoperative predictors for patients requiring ≥1 postoperative opioid refill.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data from consecutive patients who underwent arthroscopic surgery for FAIS between January 2012 and January 2017 were analyzed. Multivariate regression analysis was performed to classify patient and radiographic variables as predictive of requiring ≥1 opioid prescription refill after surgery. Patients completed the following PROs preoperatively and at 2-year follow-up: Hip Outcome Score— Activities of Daily Living subscale (HOS-ADL), HOS–Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), International Hip Outcome Tool (iHOT-12), and 100-point visual analog scale (VAS) for pain and satisfaction. Scores were compared between patients needing additional prescription opioids and those who did not.

Results:

A total of 775 patients, of whom 141 (18.2%) required ≥1 opioid prescription refill, were included in the analysis. Patients requiring opioid refills had significantly lower 2-year postoperative PRO scores compared with patients not requiring refills: HOS-ADL (79.9 ± 20.3 vs 88.7 ± 14.9), HOS-SS (64.6 ± 29.5 vs 78.2 ± 23.7), mHHS (74.2 ± 21.1 vs 83.6 ± 15.9), iHOT-12 (63.6 ± 27.9 vs 74.9 ± 24.8), and VAS satisfaction (73.4 ± 30.3 vs 82.2 ± 24.9), as well as significantly more pain (26.8 ± 23.4 vs 17.9 ± 21.8) (P ≤ .001 for all). Predictors of requiring a postoperative opioid refill included patients with active preoperative opioid use (odds ratio, 3.12 [95% confidence interval, 1.06-9.21]; P = .039) and larger preoperative alpha angles (odds ratio, 1.04 [95% confidence interval, 1.01-1.07]; P = .03).

Conclusion:

Patients requiring ≥1 opioid prescription refill after hip arthroscopy for FAIS had lower preoperative and 2-year PRO scores when compared with patients not requiring refills. Additionally, active opioid use at the time of surgery was found to be predictive of requiring additional opioids for pain management.

The Perceived Demands of Ice Hockey Goaltending Movements on the Hip and Groin Region: An Elite Coach and Player Perspective

Background:

Many ice hockey goaltending techniques force hip joints and groin muscles into extreme ranges of motion, which may increase the risk of hip and groin problems.

Purpose:

To explore how elite goaltenders and goaltending coaches perceive the demands of common goaltending techniques on the hip and groin region. We further explored differences in perception between goaltenders and their coaches as well as between junior (age <20 years) and senior (age ≥20 years) goaltenders.

Study Design:

Cross-sectional survey.

Methods:

We developed a model to categorize common ice hockey goaltending techniques into quantifiable units and invited elite goaltenders and coaches in Sweden to complete an online survey. Participants were asked to rate the perceived demands of each technique on the hip and groin using a Likert scale (not at all, slightly, somewhat, very, or extremely demanding). Using the chi-square test, the proportion of participants perceiving each technique as very or extremely demanding were compared between goaltenders and coaches as well as between senior and junior goaltenders.

Results:

We received responses from 132 goaltenders and 43 coaches. The stances most frequently perceived as very or extremely demanding were the reverse vertical horizontal post-play (40%) and the butterfly save (25%). Among transitions, movements into the post were most frequently rated as very or extremely demanding (11%–40%). Several techniques were perceived as demanding by a larger share of coaches than goaltenders (difference, 13%–46%; P < .001–.028) and a larger share of senior versus junior goaltenders (difference, 12%–20%; P = .13–.18).

Conclusion:

The post-play and the butterfly were the goaltending techniques most frequently perceived as demanding, and more coaches than goaltenders percieved these techniques demanding. The results of this study may inform injury prevention efforts for ice hockey goaltending.

Controversial Issues in Arthroscopic Surgery for Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is a common cause of painful hip in the young and middle-aged population. This condition frequently leads to a labral tear, damage of acetabular cartilage, and secondary arthritis of the hip. When nonsurgical managements are not effective, surgical procedures (open surgery and hip arthroscopy) are indicated. Due to its less invasiveness, hip arthroscopy has replaced open surgery during the last two decades. The effectiveness of arthroscopic surgery in pain relief for FAI syndrome has been well established. The procedure is also expected to slow or prevent further progression to hip arthritis. In this review, we provide the updated knowledge of arthroscopic procedures for the management of FAI syndrome.

Preoperative morbidity and joint awareness while awaiting hip arthroscopy for femoroacetabular impingement

Purpose

The Forgotten Joint Score (FJS-12) is a valid tool in the evaluation of patients undergoing hip arthroscopy, assessing the unique concept of joint awareness in the setting of a patient’s hip pathology. The preoperative burden on patients’ mental wellbeing of impaired joint function or symptoms is well established. The purpose of this study was to determine patients’ awareness of their hip joint whilst awaiting hip arthroscopy for femoroacetabular impingement, to explore any association between joint awareness and mental health status, and to determine whether this relates to time spent waiting for arthroscopy preoperatively.

Methods

A prospective database of patients undergoing hip arthroscopy between January 2018 and November 2020 was analysed. All patients with a diagnosis of femoroacetabular impingement (FAI) undergoing arthroscopic treatment were included. Questionnaires included the FJS-12, twelve item international hip outcome tool (iHOT-12), EuroQol 5D-5L (EQ-5D-5L) and the Tegner activity score. Pearson’s correlation coefficient was used to assess relationships between continuous variables.

Results

Preoperative functional outcomes were completed by 81 patients (97.5%) prior to undergoing hip arthroscopy. Median preoperative FJS-12 score was 16.67 (IQR 8.33 – 29.68). Forty-four patients reported any level of anxiety/depression preoperatively (54.3%). Preoperative FJS-12 showed a significant negative correlation with worsening mental health status (r = − 0.359, p <  0.001), and a significant positive correlation with EQ-5D-5L (r = 0.445, p <  0.001). The duration of symptoms or time on the waiting list did not correlate with increased joint awareness or worsened mental health.

Conclusion

Joint awareness is high when awaiting hip arthroscopy for FAI. Increasing levels of joint awareness correlate with poorer mental health status and poorer quality of life measures, however these parameters do not seem to be associated with increased duration of symptoms prior to surgery or time on the waiting list for surgery.

Patient-Reported Outcomes Measurement Information System Test Is Less Responsive Than Legacy Hip-Specific Patient-Reported Outcome Measures in Patients Undergoing Arthroscopy for Femoroacetabular Impingement Syndrome

Purpose

To evaluate and compare the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) computerized adaptive test and PROMIS Pain Interference (PI) instruments versus legacy patient-reported outcome measures (PROMs) in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome at 1-year follow-up.

Methods

Patients undergoing primary hip arthroscopy for the treatment of femoroacetabular impingement syndrome without concomitant procedures performed by a single surgeon between August 2018 and January 2019 were identified. The PROMIS PF score, PROMIS PI score, Hip Outcome Score–Activities of Daily Living Subscale (HOS-ADL), Hip Outcome Score–Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), International Hip Outcome Tool 12 (iHOT-12), and visual analog scale (VAS) pain score were obtained preoperatively and at 6 months and 1 year postoperatively. Bivariate correlation analyses between PROMIS and legacy PROMs were performed. The floor and ceiling effects, responsiveness, and relative efficiency (RE) of each PROM were calculated.

Results

This study included 124 patients with an average age of 32.7 ± 12.3 years. The PROMIS PF score showed very good correlations with the HOS-ADL (r = 0.73, P < .001) and mHHS (r = 0.70, P < .001) and good correlations with the HOS-SS (r = 0.62, P < .001), iHOT-12 score (r = 0.62, P < .001), and VAS pain score (r = –0.64, P < .001). The PROMIS PI score showed very good inverse correlations with the HOS-ADL (r = –0.72, P < .001) and mHHS (r = –0.79, P < .001) and good correlations with the HOS-SS (r = –0.64, P < .001), iHOT-12 score (r = –0.65, P < .001), and VAS pain score (r = 0.65, P < .001). No floor effect was observed for any measure. Ceiling effects were not observed in the PROMIS PROMs but were detected for the HOS-ADL (16.1%) and mHHS (19.3%). The effect size was large for all outcomes: iHOT-12 score, d = 1.77; HOS-ADL, d = 1.37; HOS-SS, d = 1.45; PROMIS PI score, d = 1.05; and PROMIS PF score, d = 1.01. The iHOT-12 score was more responsive than the PROMIS PI score (RE = 1.69), PROMIS PF score (RE = 1.75), HOS-ADL (RE = 1.29), and HOS-SS (RE = 1.22).

Conclusions

At 1-year follow-up, PROMIS PROMs displayed very good correlations with legacy PROMs. However, PROMIS PROMs had lower effect sizes and were not as responsive as legacy PROMs.

Level of Evidence

Level II, development of diagnostic criteria on the basis of consecutive patients.

Repeat Revision Hip Arthroscopy Outcomes Match That of Initial Revision But Not That of Primary Surgery for Femoroacetabular Impingement Syndrome

PURPOSE

To (1) report on pre- and postoperative patient-reported outcome (PRO) scores for patients undergoing repeat revision surgery in short-term follow-up and (2) compare minimal clinically important difference (MCID) and patient acceptable symptomatic state achievement between primary, revision, and repeat revision hip arthroscopy cohorts.

METHODS

Data from consecutive patients undergoing revision hip arthroscopy from January 2012 to February 2019 were retrospectively reviewed. Hips that underwent 2 revision hip arthroscopic surgeries were identified and matched 1:3 to patients undergoing revision surgery and 1:3 to patients undergoing primary surgery by age, sex, and body mass index. Baseline demographic data, surgical indications, and hip-specific PROs were collected were obtained preoperatively and at minimum 1-year follow-up. MCID was calculated individually for each cohort.

RESULTS

Twenty patients who underwent repeat revision were matched to 60 patients who underwent revision and 60 primary patients. Patients who underwent repeat revision achieved MCID on all investigated PROs at a similar rate to patients undergoing primary surgery (90.0% vs 91.7%, P = .588) and at a greater rate than patients undergoing first-time revision surgery (90.0% vs 71.7%, P = .045). Patients who underwent repeat revision achieved patient acceptable symptomatic state on all investigated PROs at a similar rate to patients who underwent first-time revision (30.0% vs 55.0%, P = .053) but at a significantly lower rate than primary patients (30.0% vs 76.7%, P < .001). However, patients undergoing repeat revision surgery had significantly lower preoperative PROs (P < .001 for all) and no significant difference in PROs at minimum 1-year follow-up compared with patients undergoing revision (P > .05). Compared with the primary cohort, patients who underwent repeat revision had significantly lower Hip Outcome Score-Activities of Daily Living (77.3 ± 16.7 vs 86.1 ± 14.4; P = .034), Hip Outcome Score-Sports Subscale (60.6 ± 27.2 vs 76.1 ± 23.8; P < .001), and modified Harris Hip Score (69.2 ± 19.3 vs 81.7 ± 16.1; P = .048) at a minimum of 1-year follow-up.

CONCLUSIONS

Second-time revision hip arthroscopy, which often requires advanced procedures, results in clinically significant improvement in PROs; however, outcomes for repeat revision cases are similar to first-time revision cases but inferior to those obtained following primary surgeries.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Activity Level and Sport Type in Adolescents Correlate with the Development of Cam Morphology

The purpose of this study was to evaluate the influence of the volume and type of sport on the development of cam-type femoroacetabular impingement and acetabular dysplasia.

Open MRI assessment of anterior femoroacetabular clearance in active and passive impingement-provoking postures

Aims

Cam and pincer morphologies are potential precursors to hip osteoarthritis and important contributors to non-arthritic hip pain. However, only some hips with these pathomorphologies develop symptoms and joint degeneration, and it is not clear why. Anterior impingement between the femoral head-neck contour and acetabular rim in positions of hip flexion combined with rotation is a proposed pathomechanism in these hips, but this has not been studied in active postures. Our aim was to assess the anterior impingement pathomechanism in both active and passive postures with high hip flexion that are thought to provoke impingement.

Methods

We recruited nine participants with cam and/or pincer morphologies and with pain, 13 participants with cam and/or pincer morphologies and without pain, and 11 controls from a population-based cohort. We scanned hips in active squatting and passive sitting flexion, adduction, and internal rotation using open MRI and quantified anterior femoroacetabular clearance using the β angle.

Results

In squatting, we found significantly decreased anterior femoroacetabular clearance in painful hips with cam and/or pincer morphologies (mean -11.3° (SD 19.2°)) compared to pain-free hips with cam and/or pincer morphologies (mean 8.5° (SD 14.6°); p = 0.022) and controls (mean 18.6° (SD 8.5°); p < 0.001). In sitting flexion, adduction, and internal rotation, we found significantly decreased anterior clearance in both painful (mean -15.2° (SD 15.3°); p = 0.002) and painfree hips (mean -4.7° (SD 13°); p = 0.010) with cam and/pincer morphologies compared to the controls (mean 7.1° (SD 5.9°)).

Conclusion

Our results support the anterior femoroacetabular impingement pathomechanism in hips with cam and/or pincer morphologies and highlight the effect of posture on this pathomechanism.

Cite this article: Bone Jt Open 2021;2(11):988–996.

Open MRI validation of a hip model driven with subject-specific motion capture data in predicting anterior femoroacetabular clearance

BACKGROUND

Cam and/or pincer morphologies (CPM) are potential precursors to hip osteoarthritis (OA) and important contributors to non-arthritic hip pain. However, only some CPM hips develop OA and/or pain, and it is not clear why. Anterior impingement between the femoral head/neck contour and acetabular rim during motion is a proposed pathomechanism. Understanding how activity and deformity combine to produce impingement may shed light on the causes of hip degeneration/pain. The objective of this study was to determine the accuracy of a subject-specific hip model driven by subject-specific motion data in predicting anterior impingement.

METHODS

We recruited 22 participants with CPM (both with and without pain) and 11 controls. We collected subject-specific 3D kinematics during squatting and sitting flexion, adduction, and internal rotation (FADIR) (an active and a passive maneuver, respectively, proposed to provoke impingement). We then developed 3D subject-specific hip models from supine 3T hip MRI scans that predicted the beta angle (a measure of anterior femoroacetabular clearance) for each frame of acquired kinematics. To assess the accuracy of these predictions, we measured the beta angle directly in the final position of squatting and sitting FADIR using open MRI scans. We selected the frame of motion data matching the static imaged posture using the least-squares error in hip angles. Model accuracy for each subject was calculated as the absolute error between the open MRI measure of beta and the model prediction of beta at the matched time frame. To make the final model accuracy independent of goodness of match between open MRI position and motion data, a threshold was set for least-squares error in hip angles, and only participants that were below this threshold were considered in the final model accuracy calculation, yielding results from 10 participants for squatting and 7 participants for sitting FADIR.

RESULTS

For squatting and sitting FADIR, we found an accuracy of 1.1°(0.8°) and 1.3°(mean (SD), and root mean squared error, respectively) and 0.5°(0.3°) and 0.6°, respectively.

CONCLUSION

This subject-specific hip model predicts anterior femoroacetabular clearance with an accuracy of about 1°, making it useful to predict anterior impingement during activities measured with motion analysis.

Association between hip joint impingement and lumbar disc disease in elite rowers

Objectives

Lumbar disc disease is a known cause of back pain. Increasingly it is thought that cam morphology of the hip may have a causal role in development of lumbar disc disease. The aim of this study was to describe the morphology of the hip and investigate the association of cam morphology with lumbar disc disease observed on MRI in elite rowers.

Methods

Cross-sectional observational study of 20 elite rowers (12 male, 8 female, mean age 24.45, SD 2.1). Assessment included clinical examination, questionnaires, 3T MRI scans of the hips and lumbar spine. Alpha angle of the hips and Pfirrmann score of lumbar discs were measured.

Results

85% of rowers had a cam morphology in at least one hip. Alpha angle was greatest at the 1 o’clock position ((bone 70.9 (SD 16.9), cartilage 71.4 (16.3)). 95% of the group were noted to have labral tears, but only 50% of the group had history of groin pain. 85% of rowers had at least one disc with a Pfirrmann score of 3 or more and 95% had a history of back pain. A positive correlation was observed between the alpha angle and radiological degenerative disc disease (correlation coefficient=3.13, p=0.012). A negative correlation was observed between hip joint internal rotation and radiological degenerative disc disease (correlation coefficient=−2.60, p=0.018).

Conclusions

Rowers have a high prevalence of labral tears, cam morphology and lumbar disc disease. There is a possible association between cam morphology and radiological lumbar degenerative disc disease, however, further investigation is required.

Automated Risk Stratification of Hip Osteoarthritis Development in Patients With Femoroacetabular Impingement Using an Unsupervised Clustering Algorithm: A Study From the Rochester Epidemiology Project

Background:

Studies evaluating the natural history of femoroacetabular impingement (FAI) are limited.

Purpose:

To stratify the risk of progression to osteoarthritis (OA) in patients with FAI using an unsupervised machine-learning algorithm, compare the characteristics of each subgroup, and validate the reproducibility of staging.

Study Design:

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

Methods:

A geographic database from the Rochester Epidemiology Project was used to identify patients with hip pain between 2000 and 2016. Medical charts were reviewed to obtain characteristic information, physical examination findings, and imaging details. The patient data were randomly split into 2 mutually exclusive sets: train set (70%) for model development and test set (30%) for validation. The data were transformed via Uniform Manifold Approximation and Projection and were clustered using Hierarchical Density-based Spatial Clustering of Applications with Noise.

Results:

The study included 1071 patients with a mean follow-up period of 24.7 ± 12.5 years. The patients were clustered into 5 subgroups based on train set results: patients in cluster 1 were in their early 20s (20.9 ± 9.6 years), female dominant (84%), with low body mass index (<19 ); patients in cluster 2 were in their early 20s (22.9 ± 6.7 years), female dominant (95%), and pincer-type FAI (100%) dominant; patients in cluster 3 were in their mid 20s (26.4 ± 9.7) and were mixed-type FAI dominant (92%); patients in cluster 4 were in their early 30s (32.7 ± 7.8), with high body mass index (≥29 ), and diabetes (17%); and patients in cluster 5 were in their early 30s (30.0 ± 9.1), with a higher percentage of males (43%) compared with the other clusters and with limited internal rotation (14%). Mean survival for clusters 1 to 5 was 17.9 ± 0.6, 18.7 ± 0.3, 17.1 ± 0.4, 15.0 ± 0.5, and 15.6 ± 0.5 years, respectively, in the train set. The survival difference was significant between clusters 1 and 4 (P = .02), 2 and 4 (P < .005), 2 and 5 (P = .01), and 3 and 4 (P < .005) in the train set and between clusters 2 and 5 (P = .03) and 3 and 4 (P = .01) in the test set. Cluster characteristics and prognosis was well reproduced in the test set.

Conclusion:

Using the clustering algorithm, it was possible to determine the prognosis for OA progression in patients with FAI in the presence of conflicting risk factors acting in combination.

How do middle-aged and older adults with chronic hip pain view their health problem and its care? A protocol for a systematic review and qualitative evidence synthesis

INTRODUCTION

Chronic hip pain in middle-aged and older adults is common and disabling. Patient-centred care of chronic hip pain requires a comprehensive understanding of how people with chronic hip pain view their health problem and its care. This paper outlines a protocol to synthesise qualitative evidence of middle-aged and older adults' views, beliefs, expectations and preferences about their chronic hip pain and its care.

METHODS AND ANALYSIS

We will perform a qualitative evidence synthesis using a framework approach. We will conduct this study in accord with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement and the Enhancing Transparency in Reporting the synthesis of Qualitative research checklist. We will search MEDLINE, CINAHL, The Cochrane Central Register of Controlled Trials, EMBASE and PsycINFO using a comprehensive search strategy. A priori selection criteria include qualitative studies involving samples with a mean age over 45 and where 80% or more have chronic hip pain. Two or more reviewers will independently screen studies for eligibility, assess methodological strengths and limitations using the Critical Appraisal Skills Programme qualitative studies checklist, perform data extraction and synthesis and determine ratings of confidence in each review finding using the Grading of Recommendations Assessment, Development and Evaluation-Confidence in the Evidence from Reviews of Qualitative research approach. Data extraction and synthesis will be guided by the Common-Sense Model of Self-Regulation. All authors will contribute to interpreting, refining and finalising review findings. This protocol is registered on PROSPERO and reported according to the PRISMA Statement for Protocols (PRISMA-P) checklist.

ETHICS AND DISSEMINATION

Ethics approval is not required for this systematic review as primary data will not be collected. The findings of the review will be disseminated through publication in an academic journal and scientific conferences.

PROSPERO REGISTRATION NUMBER

PROSPERO registration number: CRD42021246305.

Revision Hip Arthroscopy in High-Level Athletes: Minimum 2-Year Outcomes Comparison to a Propensity-Matched Primary Hip Arthroscopy Control Group

BACKGROUND

Outcomes of revision hip arthroscopy in the athletic population have not been well established.

PURPOSE

(1) To report clinical outcomes for high-level athletes undergoing revision hip arthroscopy in the setting of femoroacetabular impingement syndrome (FAIS) or labral tears and (2) to compare these outcomes against a propensity-matched group of high-level athletes undergoing primary hip arthroscopy.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data for professional, college, and high school athletes were prospectively collected and retrospectively reviewed between January 2012 and October 2018. Patients were included if they underwent revision or primary hip arthroscopy and had preoperative and minimum 2-year patient-reported outcome (PRO) scores for modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score Sports-Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain. The findings and outcomes of revision athletes were compared with a propensity-matched control group of high-level athletes undergoing primary hip arthroscopy.

RESULTS

A total of 32 hips (29 patients) undergoing revision hip arthroscopy and 92 hips (88 patients) undergoing primary hip arthroscopy were included in our final analysis with a median follow-up time of 29.5 months (95% CI, 27.2-32.1 months) and 36.5 months (95% CI, 33.5-37.7 months), respectively. Athletes undergoing revision surgery showed significant improvement in all recorded PRO measurements and achieved patient acceptable symptomatic state (PASS) and minimal clinically important difference (MCID) for mHHS at high rates (80.6% and 83.9%, respectively). When compared with a propensity-matched primary control group, patients undergoing revision surgery demonstrated lower preoperative and postoperative scores for mHHS, NAHS, and HOS-SSS, but the magnitude of improvement in functional scores was similar between groups. Athletes undergoing revision surgery achieved PASS for HOS-SSS at lower rates than the control group (P = .005), and they were less likely to attempt to return to sport compared with the control group (62.5% vs 87.0%; P < .01).

CONCLUSION

Revision hip arthroscopy is a viable treatment option to improve PROs in high-level athletes at minimum 2-year follow-up. The study group showed significant improvement in functional scores and a high rate of successful outcomes. They experienced similar magnitude of improvement as that of a propensity-matched control group; however, they achieved lower postoperative PRO scores and attempted to return to sport at lower rates.

Cam morphology but neither acetabular dysplasia nor pincer morphology is associated with osteophytosis throughout the hip: findings from a cross-sectional study in UK Biobank

OBJECTIVES

To examine whether acetabular dysplasia (AD), cam and/or pincer morphology are associated with radiographic hip osteoarthritis (rHOA) and hip pain in UK Biobank (UKB) and, if so, what distribution of osteophytes is observed.

DESIGN

Participants from UKB with a left hip dual-energy X-ray absorptiometry (DXA) scan had alpha angle (AA), lateral centre-edge angle (LCEA) and joint space narrowing (JSN) derived automatically. Cam and pincer morphology, and AD were defined using AA and LCEA. Osteophytes were measured manually and rHOA grades were calculated from JSN and osteophyte measures. Logistic regression was used to examine the relationships between these hip morphologies and rHOA, osteophytes, JSN, and hip pain.

RESULTS

6,807 individuals were selected (mean age: 62.7; 3382/3425 males/females). Cam morphology was more prevalent in males than females (15.4% and 1.8% respectively). In males, cam morphology was associated with rHOA [OR 3.20 (95% CI 2.41-4.25)], JSN [1.53 (1.24-1.88)], and acetabular [1.87 (1.48-2.36)], superior [1.94 (1.45-2.57)] and inferior [4.75 (3.44-6.57)] femoral osteophytes, and hip pain [1.48 (1.05-2.09)]. Broadly similar associations were seen in females, but with weaker statistical evidence. Neither pincer morphology nor AD showed any associations with rHOA or hip pain.

CONCLUSIONS

Cam morphology was predominantly seen in males in whom it was associated with rHOA and hip pain. In males and females, cam morphology was associated with inferior femoral head osteophytes more strongly than those at the superior femoral head and acetabulum. Further studies are justified to characterise the biomechanical disturbances associated with cam morphology, underlying the observed osteophyte distribution.

Relationship between cam morphology, hip symptoms, and hip osteoarthritis: the Musculoskeletal pain in Ullersaker STudy (MUST) cohort

BACKGROUND

The primary aim of this study was to determine the prevalence of cam morphology in a cohort of people aged 40-55 years. Secondary aims were to: (1) determine differences in participant characteristics, physical impairments, radiographic and ultrasound appearances of people with and without cam morphology; and (2) explore associations between cam morphology and radiographic measures of hip osteoarthritis (OA).

METHODS

107 people (68% women; 49 ± 4 years) from the Musculoskeletal pain in Ullensaker (MUST) Study underwent the clinical and imaging examinations. Examinations included questionnaires, hip range, functional task performance, pelvic radiographs and ultrasound. Alpha angle and radiographic hip OA (Kellgren Lawrence (KL) and minimal joint space (MJS)) were determined.

RESULTS

The prevalence of cam morphology was 42% and was bilateral in 47%. People with cam morphology were 6 times more likely to have a KL score ⩾2 (adjusted odds ratio [95% confidence intervals, p-value]) 6.386 [1.582-37.646, p = 0.012]) and 4 times more likely to have MJS <2.0 mm (adjusted odds ratio 4.032 [1.031-12.639, p = 0.045]). The prevalence of radiographic OA features ranged from 4-13% in people with cam morphology, and 0-3% in those without. Those with cam morphology also demonstrated reduced hip flexion and rotation range (p = 0.018-0.036) compared with those without. There was no association between ultrasonic features and patient reported outcomes, and cam morphology.

CONCLUSIONS

In a cohort aged 40-55 years, the prevalence of cam morphology was high (42%), with a significant relationship between cam morphology and radiographic measures of hip OA. Further longitudinal studies should explore the relationship between cam morphology and hip OA in younger people.

Arthroscopic Management of Femoroacetabular Impingement in Adolescents: A Systematic Review

BACKGROUND

Femoroacetabular impingement (FAI) is highly prevalent in adolescent athletes. There has been an increasing trend for arthroscopic surgery for FAI, and the results of several clinical studies on outcome after arthroscopic surgery for FAI are available.

PURPOSE

To conduct a systematic review to investigate the role of arthroscopic management for FAI in adolescents.

STUDY DESIGN

Systematic review.

METHODS

This systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. In August 2020, PubMed, Scopus, Google Scholar, and EMBASE were accessed. All clinical trials concerning the arthroscopic treatment for adolescents with FAI were identified. Only studies on patients aged less than 18 years at the time of surgery reporting data over a minimum follow-up of 12 months were considered.

RESULTS

Data from 406 adolescents (470 procedures; mean age at surgery, 15.9 years; mean follow-up, 30.4 months) with FAI were retrieved. At a mean of 28.0 months of follow-up, 94% of the adolescents had already returned to sport. All the scores of interest were improved at the final follow-up: visual analog scale (P = .01), modified Harris Hip Score (P < .0001), Non-Arthritic Hip Score (P = .03), Hip Outcome Score-Activities of Daily Living (P = .01), Hip Outcome Score-Sport-Specific Subscale (P < .0001), and Tegner score (P < .0001). Complications occurred in 1.1% (5/470) of procedures, and revision arthroscopy was performed in 4.7% (22/470) of procedures.

CONCLUSION

Arthroscopic surgery in adolescents with FAI achieves excellent outcomes and a high rate of return to sport, with rates of complication and revision surgery of 1% and 5%, respectively.

Movement Patterns and Their Associations With Pain, Function, and Hip Morphology in Individuals With Femoroacetabular Impingement Syndrome: A Scoping Review

OBJECTIVE

The purpose of the study was to synthesize studies of movement patterns and their association with hip pain, function/activity, and morphology in individuals with femoroacetabular impingement syndrome (FAIS).

METHODS

PubMed, SPORTDiscus, CINAHL, Embase, and Scopus databases were searched using predefined terms. Two authors independently reviewed abstracts and full texts. Studies were included if they enrolled individuals with FAIS, reported kinematic or kinetic data during movement tasks, and tested the data's associations with hip pain, function/activity, or morphology. Exclusion criteria were studies that did not evaluate associations between movement patters and pain, function/activity, or hip morphology. Additionally, studies with hip conditions other than FAIS, case reports, conference proceedings, review articles, and non-English studies were excluded. Descriptive consolidation and qualitative synthesis were performed for the included studies.

RESULTS

Of the 1155 potential studies, 5 studies met all eligibility criteria. Movement patterns were evaluated during walking (n = 4) and squatting (n = 1). Studies reported multiple associations between variables of interest. Statistically significant associations were identified between movement patterns and hip pain (n = 2), function/activity (n = 2), or morphology (n = 3). Significant associations included increased hip flexion moment impulse during walking was associated with worse pain, increased hip flexion moment during walking was associated with worse hip function, decreased hip external rotation during gait and hip internal rotation during squat were associated with larger cam deformity, and increased hip flexion moment impulse during walking was also associated with more severe acetabular cartilage abnormalities.

CONCLUSIONS

Very little current evidence has evaluated the associations between altered movement patterns and hip pain, function/activity, or morphology in individuals with FAIS, and only low-intensity tasks have been tested. These studies found some preliminary associations between altered hip biomechanics and higher hip pain, worse hip function, and specific measures of hip morphology in individuals with FAIS.

IMPACT

This review is a first step in gaining a better understanding of movement patterns and their associations with hip pain, function/activity, and morphology, which could ultimately assist with the development of movement retraining interventions and potentially improve rehabilitation outcomes for those with FAIS.

Collection of the International Hip Outcome Tool-12 Using a Smartphone Application Format Is Faster and Preferred When Compared With the Paper Version: A Pilot Study of rHip

Purpose

To evaluate the agreeability between the mobile application-based International Hip Outcome Tool-12 (iHOT-12) survey with the paper version, as well as compare the time it takes patients each of the versions, and patient preferences between the two.

Methods

Patients seen with symptomatic femoroacetabular impingement syndrome were prospectively enrolled in February 2019 and completed both the paper and application-based iHOT-12, in randomized order. Outcomes scores and time to completion were recorded for each version, and patients were also asked which they preferred. Intraclass correlation coefficient was calculated to assess for absolute agreement between the 2 versions. Bland–Altman plots were constructed to evaluate the agreeability between paper and application-based iHOT-12 scores. Bland–Altman plots were evaluated to identify systematic bias and data stratification was performed to identify sequence bias between the application and paper-based collection modalities.

Results

Twenty-nine patients (aged15-56 years) completed both the paper and application-based versions of the iHOT-12. Between the application-based and paper versions, the intraclass correlation coefficient was 0.98, and Bland–Altman analysis showed agreement without bias between versions. There was no sequence bias. Accounting for completion order, the application-based iHOT-12 was faster for patients when compared to the paper version (61.4 ± 20.3 vs 71.9 ± 23.6 seconds, P = .02). Twenty-two patients reported a version preference where 19 of 22 (86%) chose application-based (P < .001).

Conclusions

The application-based iHOT-12 demonstrated absolute agreement with the paper iHOT-12, and is faster for patients to complete. Patients preferred using the application-based iHOT-12 over the paper-based version. Application-based PROs allow for collection of patient data at more frequent time points, which may be helpful in tracking the recovery progress of patients and predicting outcomes.

Clinical Relevance

As electronic-based outcome surveys become more common, it is important to know how the results may differ from traditional paper-based surveys.

Hip Arthroscopy for Femoroacetabular Impingement Syndrome Results in 2 Recovery Patterns Based on Preoperative Pain and on Arthritis: Improvers and Non-improvers

Purpose

To analyze whether subgroups of patients could be distinguished with different functional recovery trajectories after hip arthroscopy for femoroacetabular impingement (FAI) syndrome and to identify differences between those subgroups using data from our prospective cohort registration.

Methods

We retrospectively reviewed the prospectively registered data of patients who had undergone hip arthroscopy for FAI syndrome in our clinic from 2015 through 2018. Latent class growth modeling and growth mixture modeling were used to identify and classify groups of patients according to the trajectory of functional recovery using the Hip Outcome Score–Activities of Daily Life (HOS-ADL). We used univariable analysis and descriptive statistics to explore whether differences in group membership could be identified.

Results

A total of 100 patients were analyzed. Growth mixture modeling identified 2 main types of recovery pattern after surgery: patients in whom the HOS-ADL improved significantly after surgery to 90, whom we called the “improvers” (with fast initial improvement within 3 months that is maintained during follow-up), and patients who did not significantly benefit from surgery (with only mild improvement in the HOS-ADL at 3 months and no further change during follow-up), whom we called the “non-improvers.” Univariable analysis and comparison of differences between subgroups showed higher preoperative visual analog scale scores for pain and more intraoperative arthrosis of the femoral head for the non-improvers.

Conclusions

We identified 2 main types of recovery pattern after arthroscopic treatment of FAI syndrome: improvers and non-improvers. Both groups recover in a different manner postoperatively. Preoperative pain and intraoperative arthrosis of the femoral head differed in the non-improvers compared with the improvers.

Level of evidence

Level III, retrospective cohort study.

Physical impairments in longstanding hip and groin pain: Cross-sectional comparison of patients with hip-related pain or non-hip-related groin pain and healthy controls

OBJECTIVES

To compare physical impairments between patients with hip-related pain and those with non-hip-related groin pain, and to compare both patient groups with healthy controls.

DESIGN

Cross-sectional.

PARTICIPANTS

Eighty-one hip and groin pain patients were consecutively included and categorized into having hip-related pain or non-hip-related groin pain. Twenty-eight healthy controls were recruited.

SETTINGS

Tertiary care.

MAIN OUTCOME MEASURES

All participants performed physical impairment testing including hip ROM, muscle function, and functional tasks. An analysis of covariates was used for analysis between patients groups and controls.

RESULTS

Patients with hip-related pain showed reduced hip ROM in internal rotation compared to patients with non-hip-related groin pain and controls (p ≤ 0.026, d -0.65; -0.97). No differences in muscle function or performance in functional tasks were observed between patients with hip-related pain and those with non-hip-related groin pain (p ≥ 0.136, d 0.00; 0.68). Both patient groups had worse muscle function and worse performance in functional tasks compared to controls (p ≤ 0.048, d -0.67; -1.83).

CONCLUSIONS

Both patients with and without hip-related pain had worse muscle function and worse performance in functional tasks compared to matched controls but no differences were observed between the patient groups. Only patients with hip-related pain had reduced ROM in internal rotation.

Lower pelvic tilt, lower pelvic incidence, and increased external rotation of the iliac wing in patients with femoroacetabular impingement due to acetabular retroversion compared to hip dysplasia

AIMS

The effect of pelvic tilt (PT) and sagittal balance in hips with pincer-type femoroacetabular impingement (FAI) with acetabular retroversion (AR) is controversial. It is unclear if patients with AR have a rotational abnormality of the iliac wing. Therefore, we asked: are parameters for sagittal balance, and is rotation of the iliac wing, different in patients with AR compared to a control group?; and is there a correlation between iliac rotation and acetabular version?

METHODS

A retrospective, review board-approved, controlled study was performed including 120 hips in 86 consecutive patients with symptomatic FAI or hip dysplasia. Pelvic CT scans were reviewed to calculate parameters for sagittal balance (pelvic incidence (PI), PT, and sacral slope), anterior pelvic plane angle, pelvic inclination, and external rotation of the iliac wing and were compared to a control group (48 hips). The 120 hips were allocated to the following groups: AR (41 hips), hip dysplasia (47 hips) and cam FAI with normal acetabular morphology (32 hips). Subgroups of total AR (15 hips) and high acetabular anteversion (20 hips) were analyzed. Statistical analysis was performed using analysis of variance with Bonferroni correction.

RESULTS

PI and PT were significantly decreased comparing AR (PI 42° (SD 10°), PT 4° (SD 5°)) with dysplastic hips (PI 55° (SD 12°), PT 10° (SD 6°)) and with the control group (PI 51° (SD 9°) and PT 13° (SD 7°)) (p < 0.001). External rotation of the iliac wing was significantly increased comparing AR (29° (SD 4°)) with dysplastic hips (20°(SD 5°)) and with the control group (25° (SD 5°)) (p < 0.001). Correlation between external rotation of the iliac wing and acetabular version was significant and strong (r = 0.81; p < 0.001). Correlation between PT and acetabular version was significant and moderate (r = 0.58; p < 0.001).

CONCLUSION

These findings could contribute to a better understanding of hip pain in a sitting position and extra-articular subspine FAI of patients with AR. These patients have increased iliac external rotation, a rotational abnormality of the iliac wing. This has implications for surgical therapy with hip arthroscopy and acetabular rim trimming or anteverting periacetabular osteotomy (PAO). Cite this article: Bone Jt Open 2021;2(10):813-824.

Hip muscle activity in male football players with hip-related pain; a comparison with asymptomatic controls during walking

OBJECTIVES

Compare muscle activity between male football players with and without hip-related pain. Morphological and intra-articular features of hip-related pain are proposed pre-cursors to hip osteoarthritis. Altered muscle activity is a feature of severe hip osteoarthritis, but it is not known whether differences exist earlier in the pathological spectrum.

DESIGN

Cross-sectional; SETTING: University laboratory; PARTICIPANTS: Forty-two male football players with hip-related pain; and 19 asymptomatic controls.

MAIN OUTCOME MEASURES

Hip muscle activity (Gluteus maximus, gluteus medius, tensor facia latae, adductor longus and rectus femoris) was recorded during walking using surface electromyography (EMG).

RESULTS

Men with hip-related pain had sustained rectus femoris activity prior to toe-off (47-51% of the gait cycle) (p = 0.01, ES = 0.51) unlike controls who had reduced activity. In men with severe hip-related pain, gluteus maximus EMG was sustained into mid-stance (12-20% of the gait cycle) (F = 6.15, p < 0.01) compared to controls.

CONCLUSIONS

Differences in rectus femoris and gluteus maximus activity were identified between male footballers with and without hip-related pain. The pattern of gluteus maximus EMG relative to peak, approaching mid-stance in severe hip-related pain, is consistent with observations in severe hip osteoarthritis. This supports the hypothesis that symptom severity may influence muscle activity across the spectrum of hip degeneration.