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

Femoroacetabular impingement: question-driven review of hip joint pathophysiology from asymptomatic skeletal deformity to end-stage osteoarthritis

Femoroacetabular impingement (FAI), together with its two main pathomechanisms, cam and pincer, has become a trending topic since the end of the 1990s. Despite massive academic research, this hip disorder still conceals obscure aspects and unanswered questions that only a question-driven approach may settle. The pathway that leads a FAI asymptomatic morphology through a FAI syndrome to a FAI-related osteoarthritis is little known. Contact mechanics provides a shareable and persuasive perspective: cam FAI is based on shear contact stress at joint level with consequent cartilage wear; pincer FAI, contrariwise, determines normal contact stress between acetabular rim and femoral neck and squeezes the labrum in between, with no cartilage wear for many years from the onset. Pincer prognosis is then far better than cam. As a matter of fact, cartilage wear releases fragments of extracellular matrix which in turn trigger joint inflammation, with consequently worsening lubrication and further enhanced wear. Inflammation pathobiology feeds pathotribology through a vicious loop, finally leading to hip osteoarthritis. The association of cam and pincer, possibly overdiagnosed, is a synergic combination that may damage the joint rapidly and severely. The expectations after FAI surgical correction depend strictly on chondral layer imaging, on time elapsed from the onset of symptoms and on clinic-functional preoperative level. However, preemptive surgical correction is not recommended yet in asymptomatic FAI morphology. LEVEL OF EVIDENCE: V.

Preoperative Predictors of Achieving Clinically Significant Athletic Functional Status After Hip Arthroscopy for Femoroacetabular Impingement at Minimum 2-Year Follow-Up

PURPOSE

To identify predictors of achieving clinically significant sport function in athletic patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

METHODS

Data were analyzed for all patients who treated for FAIS between 2012 to 2016 and reported being athletes, including recreational and competitive athletes. All patients had a minimum of 2-year follow-up with patient-reported athletic function in the form of the Hip Outcome Score-Sport Specific (HOS-SS), visual analog score-pain, and patient satisfaction. Achieving clinically significant sports function was defined as either reaching the minimally clinical important difference (MCID) or the patient acceptable symptomatic state (PASS) for HOS-SS at 2-year follow-up. An exploratory factor analysis was used to determine specific domains for the predictor variables and to reduce the redundancy in these variables. A logistic regression analysis was used to identify significant predictors of achieving clinically significant sports function [corrected].

RESULTS

Of 780 qualifying patients, 626 completed the 2-year minimum follow-up (80%), with a mean age and body mass index of 31.6 ± 11.9 years and 24.6 ± 8.6, respectively. A total of 500 patients (86.5%) achieved high functional status, with 77.9% achieving MCID HOS-SS and 68.7% achieving PASS HOS-SS. Logistic regression analysis identified increased the α angle (odds ratio [OR] 0.976; P = .027), preoperative pain duration (OR 0.729; P = .011), and body mass index (BMI) (OR 0.919; P = .018), as well as the presence of femoral chondral defects (OR 0.769; P = .013), as negative predictors for achieving MCID. Negative predictors for achieving PASS HOS-SS included the presence of a preoperative limp (OR 0.384; P = .013), anxiety or depression (OR 0.561; P = .041), and increased BMI (OR 0.945; P = .018) and preoperative pain duration (OR 0.987; P < .001).

CONCLUSIONS

Several predictors of achieving clinically significant sport function performance exist, including a history of anxiety or depression, BMI, preoperative α angle, limp, femoral chondral damage, *and preoperative symptom duration. Our results suggest there are both modifiable and nonmodifiable preoperative factors that have the potential to predict achieving high athletic function after hip arthroscopy for FAIS.

LEVEL OF EVIDENCE

IV, Case Series.

Femoroacetabular Impingement Patients With Decreased Femoral Version Have Different Impingement Locations and Intra- and Extraarticular Anterior Subspine FAI on 3D-CT-Based Impingement Simulation: Implications for Hip Arthroscopy

BACKGROUND

It remains unclear whether decreased femoral version (FV) causes anterior intra- or extra-articular femoroacetabular impingement (FAI). Therefore, we evaluated symptomatic hips with decreased FV, with and without cam and pincer FAI, by using computed tomography (CT)-based virtual 3-dimensional (3D) impingement simulation and compared this group with patients with normal FV and with asymptomatic hips.

PURPOSE

To investigate (1) the osseous range of motion, (2) the osseous femoral and acetabular impingement zones, and (3) whether hip impingement is extra- or intra-articular in symptomatic hips with FAI.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

An institutional review board-approved, retrospective comparative analysis was performed on a total of 84 hips in 68 participants. Of these, 37 hips in 24 symptomatic patients with FAI had decreased FV. These hips were compared with 21 hips of 18 symptomatic patients with anterior FAI with normal FV (10°-25°) and 26 asymptomatic hips with no FAI and normal FV. All patients with FAI were symptomatic and had anterior hip pain and a positive anterior impingement test. They underwent pelvic CT scans to measure FV. Decreased FV was defined as FV less than 5°. The 37 hips with decreased FV presented both with and without cam and pincer FAI. All 84 hips were evaluated by use of CT-based 3D models and a validated 3D range of motion and impingement simulation. Asymptomatic hips were contralateral normal hips imaged in patients undergoing total hip arthroplasty.

RESULTS

Hips with FAI combined with decreased FV had a significantly (P < .001) lower mean flexion (114°± 8° vs 125°± 13°) and internal rotation (IR) at 90° of flexion (18°± 6° vs 32°± 9°, P < .001) compared with the asymptomatic control group. Symptomatic patients with FAI and normal FV had flexion of 120°± 16° and IR at 90° of flexion of 23°± 15°. In a subgroup analysis, we found a significantly (P < .001) lower IR in 90° of flexion in hips with FV less than 5° combined with mixed-type FAI compared with hips with FV less than 5° without a cam- or pincer-type deformity. The maximal acetabular impingement zone for hips with decreased FV was located at the 2-o'clock position and ranged from 1 to 3 o'clock. In hips with decreased FV, most of the impingement locations were intra-articular but 32% of hips had combined intra- and extra-articular FAI in internal rotation in 90° of flexion. During the flexion-adduction-IR test performed in 10° and 20° of adduction, extra-articular subspine FAI had significantly (P < .001) higher prevalence (68% and 84%) in hips with decreased FV compared with normal hips.

CONCLUSION

Hips with FAI and decreased FV had less flexion and internal rotation in 90° of flexion compared with the asymptomatic control group. The majority of hip impingement due to low FV was intra-articular, but one-third of samples had combined intra- and extra-articular subspine FAI. Anterior extra- and intra-articular hip impingement can be present in patients who have FAI with decreased FV. This could be important for patients undergoing hip arthroscopy.

How Can We Define Clinically Important Improvement in Pain Scores After Hip Arthroscopy for Femoroacetabular Impingement Syndrome? Minimum 2-Year Follow-up Study

BACKGROUND

Patient postoperative pain is being increasingly reported in the field of hip preservation surgery. The visual analog scale (VAS) for pain is one of the most commonly utilized measures for perioperative pain assessment. Currently, there is limited understanding of clinically significant improvement in VAS pain.

PURPOSE

(1) To define the substantial clinical benefit (SCB), patient acceptable symptomatic state (PASS), and minimal clinically important difference (MCID) for the VAS pain score in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome after 2 years from surgery and (2) to identify preoperative predictors of achieving each outcome endpoint.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Data from consecutive patients who underwent primary hip arthroscopy between November 2014 and March 2017 were collected and analyzed. Baseline data and postoperative patient-reported outcome scores were recorded at 2 years postoperatively. To quantify clinical significance of outcome achievement for the VAS pain score, the MCID, PASS, and SCB were calculated.

RESULTS

A total of 976 patients were included in the final analysis. The VAS pain score threshold for achieving the MCID was defined as a decrease of 14.8; the PASS was defined as achieving a 2-year postoperative score of 21.6 points; and the SCB was defined as a decrease of 25.5 or a score of 15.4 points at 2 years. The rates of achieving the MCID, PASS, and SCB were 97.6%, 66.4%, and 71.2%, respectively. Regression analysis demonstrated that sports involvement, low body mass index, smaller preoperative alpha angle, and absence of articular damage and chondromalacia were predictive of achieving the PASS (all P < .05). Preoperative predictors for achieving the SCB included being male, no smoking history, smaller alpha angle, higher modified Harris Hip Score, and lower VAS pain score (all P < .05).

CONCLUSION

This study identified scores for VAS pain that can be used to define clinically significant outcome after arthroscopic treatment of femoroacetabular impingement syndrome. Specifically, a decrease in pain score of 14.8 was a clinically important improvement in VAS pain, while an absolute score <15.4 or a change of 25.5 represented the upper threshold of VAS pain improvement. Additionally, there were both modifiable and nonmodifiable factors that predicted achieving clinically significant levels of postoperative pain improvement.

Prevalence of Femoroacetabular Impingement Syndrome among Young and Middle-aged White Adults

Objective.

The purpose of the study was to determine the prevalence of femoroacetabular impingement syndrome (FAIS) in white adults 20 to 49 years of age.

Methods.

Participants were white men and women aged 20–49 years, recruited through random digit dialing from the population of Metro Vancouver, British Columbia, Canada. Participants filled out a self-administered questionnaire and underwent a physical examination and radiographs of both hips. FAIS was defined as a combination of hip symptoms, physical signs of impingement, and radiological findings of cam or pincer morphology as recommended by the Warwick Agreement. All analyses were weighted to reflect the population from which the sample was drawn.

Results.

Data were obtained for 500 participants. In the study population, 48.9% were males and the age distribution was 32.2%, 31.4%, and 36.4% in the groups 20–29, 30–39, and 40–49 years, respectively. The physical signs of impingement correlated significantly with symptoms, but there was no significant association between either symptoms or physical examination with radiographic findings. FAIS on either side was found in 3.0% (95% CI 1.5–4.5) of the population.

Conclusion.

In this study, FAIS was present in 3% of whites aged 20–49 years. Further research is needed to develop consistent criteria for assessing hip symptoms, physical signs, and hip joint morphology, and to better understand the relationships between them.

The clinical presentation, diagnosis and pathogenesis of symptomatic sports-related femoroacetabular impingement (SRFAI) in a consecutive series of 1021 athletic hips

AIM

To examine the pathogenesis and clinical presentation of sports-related femoroacetabular impingement (SRFAI) in a large consecutive series of symptomatic athletes.

METHODS

Between January 2009 and February 2017 prospectively collected data from competitive athletes within the Gaelic Athletic Association (GAA), and who subsequently underwent arthroscopic treatment for symptomatic FAI, were analysed. Data was collected using internationally validated health questionnaires (Harris Hip Score, UCLA, SF-36, WOMAC) and recognised clinical (ROM, symptom presentation, provocation tests) and radiological (AP pelvis, Dunn, False profile) indicators/measures of FAI.

RESULTS

A total of 1021 consecutive cases (mean 26.6 ± 6.2 years) were included. In every case, conservative treatment failed to resolve symptoms with athletes attending an average of 2.4 ± 1.1 health care professionals prior to referral. Symptoms developed gradually (78%) and consisted primarily of groin pain (76.1%) and hip stiffness (76.5%) following activity. An acetabular rim deformity (pincer) was present in all cases; a cam deformity in 72.1%. The prevalence and degree of cam deformity increased with progressing age groups (p < 0.001); mean lateral centre-edge angle remained static (p = 0.456). Increasing CEA, alpha angle and presence of rim fracture was associated with a reduction in all ranges of hip movement (p < 0.001).

CONCLUSION

Symptomatic SRFAI presented in this large series of GAA athletes failed to resolve with non-operative treatment. Increasing hip deformity resulted in poorer ROM. Abnormal acetabular morphology remains static with increasing athletic age while cam deformity is progressive and most likely a secondary pathology.

Unpicking observational relationships between hip shape and osteoarthritis: hype or hope?

PURPOSE OF REVIEW

To review recent findings concerning the observational relationship between hip shape and hip osteoarthritis (HOA) and their shared genetic influences, and the potential for clinical application.

RECENT FINDINGS

Recent observational studies have strengthened the evidence that specific shape deformities, such as cam and acetabular dysplasia, are related to HOA. Statistical shape modelling has emerged as a method to measure hip shape holistically, with the added advantage that this can be applied to dual X-ray absorptiometry scan images. This has led to several additional aspects of hip shape variation being identified, such as a wider femoral neck and larger lesser trochanter, in association with HOA. Furthermore, this method has formed the basis of genetic studies identifying novel genetic influences on hip shape, several of which are shared with known genetic risk factors for HOA.

SUMMARY

Shared genetic influences of hip shape and HOA raise the possibility that hip shape plays a casual role in the development of HOA, justifying preventive approaches aiming to combat these adverse consequences.

Are Hip Physical Examination Findings Predictive of Future Lower-Body Injury Rates in Elite Adolescent Female Soccer Athletes at Minimum 5-Year Follow-Up?

CONTEXT

Although elite adolescent female soccer athletes have unique injury risk factors and management challenges, limited epidemiological data exist for this population.

OBJECTIVE

To describe lower-body injury patterns and to determine whether a screening hip physical examination is predictive of future injuries in elite adolescent female soccer athletes.

DESIGN

Prospective cohort study.

SETTING

One US premier soccer club.

PARTICIPANTS

One hundred seventy-seven female soccer athletes aged 10-18 years (mean [SD] 14.6 [1.8] y) completed a demographic questionnaire and screening hip physical examination that included range of motion and provocative tests.

INTERVENTIONS

At least 5 years after baseline screening, athletes completed an electronic follow-up injury survey. Injury was defined as pain that interfered with sporting activity.

MAIN OUTCOME MEASURES

In addition to descriptive analyses of athletes' injury profiles, associations between players' baseline demographics and subsequent injury profiles were evaluated using chi-square tests, and potential predictors of injury based on players' baseline hip examinations were evaluated using multivariable logistic regression.

RESULTS

Ninety-four of 177 athletes (53%) were contacted for follow-up, and 88/94 (93.6%) completed the survey. With mean follow-up of 91.9 (9.3) months (range 66-108 mo), 42/88 (47.7%) reported sustaining a new lower-body injury. The low back was the most common injury region (16/42, 38.1%). Almost half of all injured athletes (20/42, 47.6%) sustained overuse injuries, and 16/42 (38.1%) had an incomplete recovery. Higher body mass index and reaching menarche were associated with sustaining an injury (P = .03 and .04, respectively). Athletes' baseline hip examinations were not predictive of their subsequent rate of lower-body, lumbopelvic, overuse, or incomplete recovery injury (all P > .05).

CONCLUSIONS

Lower-body injuries were common in elite adolescent female soccer athletes, with over one third of injured athletes reporting permanent negative impact of the injury on their playing ability. Baseline hip physical examinations were not associated with future injury rate.

Italian consensus statement (2020) on return to play after lower limb muscle injury in football (soccer)

Return to play (RTP) decisions in football are currently based on expert opinion. No consensus guideline has been published to demonstrate an evidence-based decision-making process in football (soccer). Our aim was to provide a framework for evidence-based decision-making in RTP following lower limb muscle injuries sustained in football. A 1-day consensus meeting was held in Milan, on 31 August 2018, involving 66 national and international experts from various academic backgrounds. A narrative review of the current evidence for RTP decision-making in football was provided to delegates. Assembled experts came to a consensus on the best practice for managing RTP following lower limb muscle injuries via the Delphi process. Consensus was reached on (1) the definitions of 'return to training' and 'return to play' in football. We agreed on 'return to training' and RTP in football, the appropriate use of clinical and imaging assessments, and laboratory and field tests for return to training following lower limb muscle injury, and identified objective criteria for RTP based on global positioning system technology. Level of evidence IV, grade of recommendation D.

Concurrent validity of a patient self-administered examination and a clinical examination for femoroacetabular impingement syndrome

Objective

Telehealth has been established as a viable option for improved access and timeliness of care. Physician-guided patient self-evaluation may improve the viability of telehealth evaluation; however, there are little data evaluating the efficacy of self-administered examination (SAE). This study aims to compare the diagnostic accuracy of a patient SAE to a traditional standardised clinical examination (SCE) for evaluation of femoroacetabular impingement syndrome (FAIS).

Methods

75 patients seeking care for hip-related pain were included for participation. All patients underwent both SAE and SCE and were randomised to the order of the examinations. Diagnostic accuracy statistics were calculated for both examination group for a final diagnosis of FAIS. Mean diagnostic accuracy results for each group were then compared using Mann-Whitney U non-parametric tests.

Results

The diagnostic accuracy of individual SAE and SCE manoeuvres varied widely. Both SAE and SCE demonstrated no to moderate change in post-test probability for the diagnosis of FAIS. Although low, SAE demonstrated a statistically greater mean diagnostic accuracy compared with the SCE (53.6% vs 45.5%, p=0.02).

Conclusion

Diagnostic accuracy was statistically significantly higher for the self-exam than for the traditional clinical exam although the difference may not be clinically relevant. Although the mean accuracy remains relatively low for both exams, these values are consistent with hip exam for FAIS reported in the literature. Having established the validity of an SAE, future investigations will need to evaluate implementation in a telehealth setting.

Danish Hip Arthroscopy Registry: predictors of outcome in patients with femoroacetabular impingement (FAI)

PURPOSE

Predictors of outcome after femoroacetabular impingement (FAI) surgery are not well-documented. This study presents data from the Danish Hip Arthroscopy Registry (DHAR) for such analyses. The purpose of this study was to identify predictors of poor outcome after FAI surgery in a Danish FAI population. The primary hypothesis was that older patients, patients with severe cartilage damage and female patients might have inferior outcome results compared with younger patients, patients with minor cartilage damage and male patients.

METHODS

Radiological and surgical data as well as patient-reported outcome measures (PROM) from FAI patients in DHAR between January 2012 and May 2015 were collected. PROMs consisting of Copenhagen Hip and Groin Outcome Score (HAGOS), quality of life (EQ-5D), Hip Sports Activity Scale (HSAS) and Numeric Rating Scale (NRS) pain scores were assessed. The patients were divided into three age groups (< 25, 25-39 and ≥ 40 years). Cartilage injuries were classified according to International Cartilage Repair Society (ICRS) (femoral side) and modified Becks (acetabular side) classifications. A non-parametric statistic method was used to analyze the differences between the preoperative and postoperative PROM values.

RESULTS

Data from 2054 FAI procedures in DHAR was collected. 53% of the procedures were done in female patients. All HAGOS sub-scales, EQ-5D, HSAS and NRS pain (rest and walk) demonstrated significant improvements in all age groups at follow-up. Comparison between age groups demonstrated poorer outcomes in both older age groups when compared with the < 25 years age group at 1- and 2-year follow-ups. Higher degrees of femoral and acetabular cartilage injury did have a negative influence on outcome at follow-up. Comparison between genders demonstrated lower preoperative outcomes in females and lower outcome score (HSAS) 1 and 2 years after FAI surgery.

CONCLUSIONS

Age above 25 and major cartilage injury might negatively affect the outcome of surgery, however, gender could not be identified as a negative predictor of clinical outcome after FAI surgery, but might negatively affect sports participation in females.

LEVEL OF EVIDENCE

III, prospective cohort study.

Deep hip muscle activation during squatting in femoroacetabular impingement syndrome

BACKGROUND

Deep hip muscle retraining is a common objective of non-operative management for femoroacetabular impingement (FAI) syndrome. These muscles are considered to have an important role in hip joint stabilization, however, it is unclear whether their function is altered in the presence of hip pathology. This exploratory study aimed to investigate activation patterns of the hip muscles during two squatting tasks in individuals with and without FAI syndrome.

METHODS

Fifteen individuals with FAI syndrome (symptoms, clinical examination and imaging) and 14 age- and sex-comparable healthy controls underwent testing. Intramuscular fine-wire and surface electrodes recorded electromyographic activity of selected deep and superficial hip muscles during the squatting tasks. Activation patterns from individual muscles were compared between-groups using a wavelet-based linear mixed effects model (P < 0.05).

FINDINGS

There were no between-group differences for squat depth or speed during descent or ascent for either task. Participants with FAI syndrome exhibited patterns of activation that differed significantly to controls across all muscles (P < 0.05) when squatting using their preferred strategy. Unlike controls, participants with FAI syndrome exhibited a pattern of activation for obturator internus during descent that was similar in amplitude to ascent, despite the contrasting contraction type (i.e. eccentric vs concentric).

INTERPRETATION

Individuals with FAI syndrome appear to implement a protective strategy as the hip descends towards the impingement position. Future studies should examine patients prospectively to establish whether these strategies are counterproductive for pathology and warrant rehabilitation.

Return to Basketball After Hip Arthroscopy: Minimum 2-Year Follow-up

PURPOSE

To present minimum 2-year patient-reported outcomes (PROs) and return to sport (RTS) data for a population of basketball players after hip arthroscopy.

METHODS

Data were prospectively collected and retrospectively reviewed for all patients who underwent hip arthroscopy between February 2009 and May 2014. Patients with preoperative and minimum 2-year postoperative PROs, visual analog scale score for pain, and satisfaction, who regularly played basketball within 1 year before surgery, and who attempted to RTS met the inclusion criteria. Exclusion criteria were previous ipsilateral hip surgery or conditions such as fracture, dysplasia, or femoral avascular necrosis. Patients were matched 1:1 to a control group composed of those who did not play any sports before surgery, based on the following matching criteria: age ±5 years, sex, and body mass index ±5. Statistical analysis was performed to determine significant differences in PROs. Conversion to total hip arthroplasty (THA) was considered an endpoint.

RESULTS

Thirty-one patients (81.6%) met inclusion criteria with follow-up of 46.8 ± 20.6 months. The mean age was 30.0 ± 12.3, and the mean body mass index was 26.3 ± 6.5. Male patients (64.5%) outnumbered female patients (35.5%). A majority of the players (54.8%) identified themselves as recreational athletes; the remainder competed at the high school, collegiate, amateur, or professional level. There was significant (P < .001) improvement in all PRO measures and visual-analog scale scores from baseline to a minimum 2-year follow-up. At the most recent follow-up, mean patient satisfaction was 8.1 ± 2.1. Twenty-two (78.6%), and 23 patients (82.1%) achieved the patient acceptable symptom state on the modified Harris Hip Score and the Hip Outcomes Score-Sports Specific Subscale. Twenty-one (75.0%) and 17 (60.7%) patients had a minimal clinically important difference on the modified Harris Hip Score and the Hip Outcomes Score-Sports Specific Subscale, respectively. Three patients (9.7%) with an average age of 47.5 (P = .023) converted to THA at a mean of 35.9 ± 7.2 (range 29.66-43.75) months after arthroscopy. At the most recent follow-up, the RTS rate was 83.9%. Subjective ability level was the same or higher in 23 patients (74.2%).

CONCLUSION

Hip arthroscopy in basketball athletes demonstrates a significant increase in PROs, a high RTS rate, and a low risk of complications. Hip arthroscopy may be considered in basketball players <40 years old for whom nonoperative treatment fails and who have a significantly limited level of play. Careful patient selection and counseling should be used when considering hip arthroscopy in basketball players >40 years old because there may be a high rate of conversion to THA.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Patient-Specific 3-D Magnetic Resonance Imaging-Based Dynamic Simulation of Hip Impingement and Range of Motion Can Replace 3-D Computed Tomography-Based Simulation for Patients With Femoroacetabular Impingement: Implications for Planning Open Hip Preservation Surgery and Hip Arthroscopy

BACKGROUND

Femoroacetabular impingement (FAI) is a complex 3-dimensional (3D) hip abnormality that can cause hip pain and osteoarthritis in young and active patients of childbearing age. Imaging is static and based on 2-dimensional radiographs or computed tomography (CT) scans. Recently, CT-based 3D impingement simulation was introduced for patient-specific assessments of hip deformities, whereas magnetic resonance imaging (MRI) offers a radiation-free alternative for surgical planning before hip arthroscopic surgery.

PURPOSE

To (1) investigate the difference between 3D models of the hip, (2) correlate the location of hip impingement and range of motion (ROM), and (3) correlate diagnostic parameters while comparing CT- and MRI-based osseous 3D models of the hip in symptomatic patients with FAI.

STUDY DESIGN

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

METHODS

The authors performed an institutional review board-approved comparative and retrospective study of 31 hips in 26 symptomatic patients with FAI. We compared CT- and MRI-based osseous 3D models of the hip in the same patients. 3D CT scans (slice thickness, 1 mm) of the entire pelvis and the distal femoral condyles were obtained. Preoperative MRI of the hip was performed including an axial-oblique T1 VIBE sequence (slice thickness, 1 mm) and 2 axial anisotropic (1.2 × 1.2 × 1 mm) T1 VIBE Dixon sequences of the entire pelvis and the distal femoral condyles. Threshold-based semiautomatic reconstruction of 3D models was performed using commercial software. CT- and MRI-based 3D models were compared with specifically developed software.

RESULTS

(1) The difference between MRI- and CT-based 3D models was less than 1 mm for the proximal femur and the acetabulum (median surface distance, 0.4 ± 0.1 mm and 0.4 ± 0.2 mm, respectively). (2) The correlation for ROM values was excellent (r = 0.99, P < .001) between CT and MRI. The mean absolute difference for flexion and extension was 1.9°± 1.5° and 2.6°± 1.9°, respectively. The location of impingement did not differ between CT- and MRI-based 3D ROM analysis in all 12 of 12 acetabular and 11 of 12 femoral clock-face positions. (3) The correlation for 6 diagnostic parameters was excellent (r = 0.98, P < .001) between CT and MRI. The mean absolute difference for inclination and anteversion was 2.0°± 1.8° and 1.0°± 0.8°, respectively.

CONCLUSION

Patient-specific and radiation-free MRI-based dynamic 3D simulation of hip impingement and ROM can replace CT-based 3D simulation for patients with FAI of childbearing age. On the basis of these excellent results, we intend to change our clinical practice, and we will use MRI-based 3D models for future clinical practice instead of CT-based 3D models. This allows radiation-free and patient-specific preoperative 3D impingement simulation for surgical planning and simulation of open hip preservation surgery and hip arthroscopic surgery.

Professional soccer is associated with radiographic cam and pincer hip morphology

PURPOSE

Femoroacetabular impingement (FAI) syndrome is characterized by a triad: symptoms, clinical signs and imaging findings. Some individuals, especially athletes, have only imaging alterations. The objective of this study was to evaluate the prevalence of cam and pincer morphology in professional soccer players compared with a control group of non-athletes and to investigate the association between the age at which players start playing competitive soccer more than three times per week and duration of the soccer career with the prevalence of these radiographic findings.

METHODS

The prevalence of cam and pincer morphology in sixty professional adult male soccer players and thirty-two male controls was determined using pelvic anteroposterior radiography. Data were recorded for all hips and correlated with the age at which the players started competitive soccer practice and with the duration of their soccer career.

RESULTS

The prevalence of morphological FAI in the soccer players was 92.5% versus 28.1% in the controls (p < 0.001). The duration of the soccer career was positively correlated with the alpha angle (p = 0.033) and negatively correlated with the retroversion index (p = 0.009). The age at which competitive play began was inversely correlated with the alpha angle (p < 0.001).

CONCLUSION

The study showed a high prevalence of cam and pincer morphology in Brazilian professional soccer players compared with controls. The duration of the soccer career was associated with an increased alpha angle and a decreased retroversion index, and the age at which competitive soccer participation began was negatively associated with alpha angle values. Finally, this manuscript provides data about the association between greater exposure to soccer and cam and pincer morphological changes in the hip; specifically, cam morphology was more common in patients who began participating in sports at earlier ages. This information serves as an alert for coaches of youth teams to manage the training load in youth athletes.

LEVEL OF EVIDENCE

III.

Hip-related groin pain, patient characteristics and patient-reported outcomes in patients referred to tertiary care due to longstanding hip and groin pain: a cross-sectional study

BACKGROUND

Due to advances in hip arthroscopy, the number of surgical procedures has increased dramatically. The diagnostic challenge in patients with longstanding hip and groin pain, as well as the increasing number of hip arthroscopies, may lead to a higher number of patients referred to tertiary care for consideration for surgery. Therefore, the aims were: 1) to describe the prevalence of hip-related groin pain in patients referred to tertiary care due to longstanding hip and groin pain; and 2) to compare patient characteristics and patient-reported outcomes for patients categorized as having hip-related groin pain and those with non-hip-related groin pain.

METHODS

Eighty-one patients referred to the Department of Orthopedics at Skåne University Hospital for longstanding hip and groin pain were consecutively included and categorized into hip-related groin pain or non-hip-related groin pain using diagnostic criteria based on current best evidence (clinical examination, radiological examination and intra-articular block injection). Patient characteristics (gender (%), age (years), BMI (kg/m²)), results from the Hip Sports Activity Scale (HSAS), the SF-36, the Copenhagen Hip and Groin Outcome Score (HAGOS), and pain distribution (pain manikin) were collected. Parametric and non-parametric statistics were used as appropriate for between-group analysis.

RESULTS

Thirty-three (47%) patients, (30% women, 70% men, p < 0.01), were categorized as having hip-related groin pain. The hip-related groin pain group had a higher activity level during adolescence (p = 0.013), and a higher pre-injury activity level (p = 0.034), compared to the non-hip-related groin pain group. No differences (mean difference (95% CI)) between hip-related groin pain and non-hip-related groin pain were observed for age (0 (- 4; 4)), BMI (- 1.75 (- 3.61; 0.12)), any HAGOS subscales (p ≥ 0.318), any SF-36 subscales (p ≥ 0.142) or pain distribution (p ≥ 0.201).

CONCLUSIONS

Only half of the patients referred to tertiary care for long-standing hip and groin pain, who were predominantly men with a high activity level, had hip-related groin pain. Self-reported pain localization and distribution did not differ between patients with hip-related groin pain and those with non-hip-related groin pain, and both patient groups had poor perceived general health, and hip-related symptoms and function.

Do psychological factors or radiographic severity play a role in the age of onset in symptomatic developmental dysplasia of hip and femoroacetabular impingement syndrome?

Background

Age of onset in symptomatic developmental dysplasia of the hip (DDH) and femoroacetabular impingement syndrome (FAIS) varies. The purpose of this study was to investigate whether psychological factors, radiographic, and clinical variables were related to age of onset of hip pain in DDH and FAIS.

Methods

We collected demographic, clinical, and radiographic data on 56 DDH and 84 FAIS patients. Each was diagnosed based on radiographic findings and clinical history. Age of onset was operationalized by subtracting patient reported duration of symptoms from patient age at presentation. Pain catastrophizing (PCS) and depression were assessed with the pain catastrophizing scale and hospital anxiety and depression scale (HADS), respectively. Multiple linear regression modeling, with Lasso variable selection, was implemented.

Results

Pain catastrophizing, anxiety, and depression were not significantly related to age of DDH onset (p-values > 0.27) or age of FAIS onset (p-values > 0.29). LASSO-penalized linear regression revealed alpha Dunn angle, Tonnis grade, prior hip surgery, WOMAC pain score, and iHOT total score were associated with age of onset in FAIS (Adjusted R² = 0.3099). Lateral center edge angle (LCEA), alpha frog angle, Tonnis grade, SF12 physical functioning, and body mass index (BMI) were associated with age of DDH onset (Adjusted R² = 0.3578).

Conclusions

Psychological factors, as measured by PCS and HADS, were not associated with age of onset in DDH or FAIS. Functional impairment as measured by WOMAC pain and impaired active lifestyle as measured by iHOT were found to affect age of FAIS onset. For DDH, impaired physical functioning and increasing BMI were found to be associated with age of onset. Severity of the disease, as measured radiographically by LCEA and alpha Dunn angle, was also found to be associated with earlier age of onset in DDH and FAIS, respectively. A patient’s radiographic severity may have more of a relationship to the onset of pain than physiologic factors.

An Anatomical Study of the Anterosuperior Capsular Attachment Site on the Acetabulum

BACKGROUND

Despite the fact that many surgeons perform partial capsular detachment from the anterosuperior aspect of the acetabulum to correct acetabular deformities during hip arthroscopy, few studies have focused on whether these detachments influence hip joint stability. The aim of this study was to investigate the capsular attachment on the anterosuperior aspect of the acetabulum. We hypothesized that the attachment on the inferior aspect of the anterior inferior iliac spine (AIIS) is wide and fibrocartilaginous and might have a substantial role in hip joint stability.

METHODS

Fifteen hips from 9 cadavers of Japanese donors were analyzed. Eleven hips were analyzed macroscopically, and the other 4 were analyzed histologically. In all specimens, the 3-dimensional morphology of the acetabulum and AIIS was examined using micro-computed tomography (micro-CT).

RESULTS

Macroscopic analysis showed that the widths of the capsular attachments varied according to the location, and the attachment width on the inferior edge of the AIIS was significantly larger than that on the anterosuperior aspect of the acetabulum. Moreover, the capsular attachment on the inferior edge of the AIIS corresponded with the impression, which was identified by micro-CT. Histological analysis revealed that the hip joint capsule on the inferior edge of the AIIS attached to the acetabulum adjacent to the proximal margin of the labrum. In addition, the hip joint capsule attached to the inferior edge of the AIIS via the fibrocartilage.

CONCLUSIONS

The capsular attachment on the inferior edge of the AIIS was characterized by an osseous impression, large attachment width, and distributed fibrocartilage.

CLINICAL RELEVANCE

It appeared that the capsular attachment on the inferior edge of the AIIS was highly adaptive to mechanical stress, on the basis of its osseous impression, attachment width, and histological features. Anatomical knowledge of the capsular attachment on the inferior edge of the AIIS provides a better understanding of the pathological condition of hip joint instability.

Prevalence and Clinical Implications of Chondral Injuries After Hip Arthroscopic Surgery for Femoroacetabular Impingement Syndrome

BACKGROUND

Studies on the effect of partial- and full-thickness chondral damage of the hip on outcomes and the ability to achieve meaningful clinical outcomes are limited.

PURPOSE

To determine the effect of full- and partial-thickness chondral injuries on 2-year outcomes in patients undergoing hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) compared with patients without chondral damage, and to identify significant predictors of achieving the patient acceptable symptomatic state (PASS) and minimal clinically important difference (MCID).

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data from consecutive patients with evidence of chondromalacia at the time of primary hip arthroscopic surgery with routine capsular closure for the treatment of FAIS by a single fellowship-trained surgeon between January 2012 and September 2016 were reviewed. Patients were divided into groups with partial-thickness (grade I-III) or full-thickness (grade IV) chondral defects and matched by age and body mass index (BMI) to patients without chondral injuries. Preoperative and postoperative outcomes were compared among the 3 groups, and a binary logistic regression analysis was utilized to identify significant predictors of achieving the MCID and PASS.

RESULTS

There were 634 patients included in the analysis, with a mean age of 34.5 ± 10.9 years and a mean BMI of 25.2 ± 4.7 kg/m². A total of 493 (77.8%) patients had no evidence of chondral damage, 92 (14.5%) patients had partial-thickness chondral defects, and 49 (7.7%) patients had full-thickness chondral defects. There were statistically significant differences in the Hip Outcome Score (HOS)-Activities of Daily Living, HOS-Sports Subscale, modified Harris Hip Score, pain, and satisfaction (P < .01) among the 3 groups. Patients with grade IV chondromalacia experienced the poorest outcomes and lowest percentage of achieving the PASS. Predictors for achieving any PASS threshold included preoperative alpha angle (odds ratio [OR], 0.96; P = .016), absence of preoperative limping (OR, 7.25; P = .002), absence of preoperative chronic pain (OR, 5.83; P = .019), primary hip arthroscopic surgery (OR, 0.17; P = .050), patients who self-identified as runners (OR, 2.27; P = .037), and Tönnis grade 0 (OR, 2.86; P = .032). Male sex (OR, 2.49; P = .015) was the only predictor of achieving any MCID threshold.

CONCLUSION

Patients with grade IV chondral defects experienced worse functional outcomes, lower satisfaction, and increased pain when compared with both patients without chondral damage or grade I-III chondromalacia at 2-year follow-up. Several predictors were associated with achieving clinically significant function in patients undergoing hip arthroscopic surgery for FAIS.

Patients With Borderline Hip Dysplasia Achieve Clinically Significant Outcome After Arthroscopic Femoroacetabular Impingement Surgery: A Case-Control Study With Minimum 2-Year Follow-up

BACKGROUND

There is a growing trend for hip arthroscopists to treat patients with borderline hip dysplasia (BHD) for femoroacetabular impingement syndrome (FAIS) without addressing the acetabular coverage. However, the literature of outcomes and failure rates for these patients is conflicting.

PURPOSE

(1) To identify whether patients with BHD achieved 2-year similar patient-reported outcome, minimal clinically important difference (MCID), and patient acceptable symptomatic state (PASS) when compared with patients without BHD and (2) to identify predictors for achieving the MCID and PASS among patients with BHD who are undergoing hip arthroscopy for FAIS.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data from consecutive patients who underwent primary hip arthroscopy with routine capsular closure for the treatment of FAIS between January 2012 and January 2017 were collected and retrospectively analyzed. Patients with BHD (lateral center-edge angle [LCEA], 20°-25°) were matched 2:1 by age, sex, and body mass index (BMI) to control patients with normal acetabular coverage (LCEA, >25°-40°). Patient-reported outcome, MCID, and PASS were compared between the groups. Multivariate logistic regression analysis identified significant predictors of achieving the MCID and PASS in the BHD group.

RESULTS

The MCID in the BHD group was defined as 9.2, 13.7, 8.5, and 15.2 for the Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sport Specific, modified Harris Hip Score, and iHOT-12, respectively. Threshold scores for achieving the PASS in both groups were 87.9, 76.4, 78.1, and 60.0. A total of 112 patients were identified as having BHD (LCEA, 20°-25°) and were matched to 224 controls. Both groups saw statistically significant increases in score averages over the 2-year period; however, the differences between them were not statistically significant (P > .05 for all). There was no statistical difference in the frequency of the BHD and non-BHD cohorts achieving the MCID on at least 1 threshold score (86.6% vs 85.6%, P = .837) and the PASS (78.6% vs 79.8%, P = .79). There was, however, a statistically significant difference between the rates of patients with and without BHD achieving the PASS on the modified Harris Hip Score threshold (62.5% vs 74.5%, P = .028). The final logistic models demonstrated that lower BMI (odds ratio [OR], 0.872; P = .029), lower preoperative alpha angle (OR, 0.965; P = .014), and female sex (OR, 3.647; P = .03) are independent preoperative predictors of achieving the MCID, while lower preoperative alpha angle (OR, 0.943; P = .018) and self-reported limp (OR, 18.53; P = .007) are independent preoperative predictors of achieving the PASS.

CONCLUSION

Outcome improvements in patients with BHD who are undergoing arthroscopic treatment with capsular closure for FAIS are not significantly different from patients with normal acetabular coverage. Lower BMI, lower alpha angle, absence of limp, and female sex are preoperative predictors of achieving meaningful clinically significant outcome improvements in patients with BHD.

Demographic and Radiographic Factors Associated With Intra-articular Hip Cartilage Injury: A Cross-sectional Study of 1511 Hip Arthroscopy Procedures

BACKGROUND

Moderate to severe (grade 3-4) hip joint cartilage injury seems to impair function in patients with femoroacetabular impingement syndrome.

PURPOSE

To investigate whether demographic and radiographic factors were associated with moderate to severe hip joint cartilage injury.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Patients were identified in the Danish Hip Arthroscopy Registry. The outcome variables were acetabular cartilage injury (modified Beck grade 0-2 vs 3-4) and femoral head cartilage injury (International Cartilage Repair Society grade 0-2 vs 3-4). Logistic regressions assessed the association with the following: age (<30 vs 30-50 years); sex; sport activity level (Hip Sports Activity Scale); alpha angle (AA) assessed as normal (AA <55°), cam (55°≤ AA <78°), or severe cam (AA ≥78°); lateral center-edge angle (LCEA) assessed as normal (25°≤ LCEA ≤ 39°), pincer (LCEA >39°), or borderline dysplasia (LCEA <25°); joint space width (JSW) assessed as normal (JSW >4.0 mm), mild reduction (3.1 mm ≤ JSW ≤ 4.0 mm), or severe reduction (2.1 mm ≤ JSW ≤ 3.0 mm).

RESULTS

A total of 1511 patients were included (mean ± SD age: 34.9 ± 9.8 years). Male sex (odds ratio [OR], 4.42), higher age (OR, 1.70), increased AA (cam: OR, 2.23; severe cam: OR, 4.82), and reduced JSW (mild: OR, 2.04; severe: OR, 3.19) were associated (P < .05) with Beck grade 3-4. Higher age (OR, 1.92), increased Hip Sports Activity Scale (OR, 1.13), borderline dysplasia (OR, 3.08), and reduced JSW (mild: OR, 2.63; severe: OR, 3.04) were associated (P < .05) with International Cartilage Repair Society grade 3-4.

CONCLUSION

Several demographic and radiographic factors were associated with moderate to severe hip joint cartilage injury. Most notably, increased cam severity and borderline dysplasia substantially increased the risk of grade 3-4 acetabular and femoral head cartilage injury, respectively, indicating that specific deformity may drive specific cartilage injury patterns in the hip joint.

Extra-articular hip impingement: clinical presentation, radiographic findings and surgical treatment outcomes

Femoroacetabular impingement syndrome is classically thought of as either a cam or pincer deformity causing abnormal bony contact resulting in labral pathology. However, alternate patterns of hip impingement can occur, but tend to be less commonly recognized or studied. Collectively termed 'extra-articular impingement', four subgroups of impingement can contribute to non-arthritic hip pain and disability: iliopsoas impingement, subspine impingement, ischiofemoral impingement and trochanteric-pelvic impingement. The purpose of this review article is to highlight the pertinent points to aid in proper clinical and radiographic evaluation to allow appropriate diagnosis. Additionally, a review of potential surgical treatment options and resultant outcomes will also be provided.

Return to Duty After Mini-Open Arthroscopic-Assisted Treatment of Femoroacetabular Impingement in an Active Military Population

Purpose

To report the return-to-duty rate and surgical outcomes in a military population after mini-open arthroscopic-assisted surgery for femoroacetabular impingement (FAI) in an effort to affirm its efficacy.

Methods

A retrospective review of consecutive active-duty patients receiving mini-open arthroscopic-assisted surgery for FAI between 2007 and 2011 was performed. Patients younger than 18 years, non–active-duty patients, and patients with prior hip surgery were excluded. Demographic, radiographic, and duty-status data were collected. The primary outcome measure was a return to duty. Outcome scores were obtained in a proportion of the cohort, including the modified Harris Hip Score, Single Assessment Numeric Evaluation score, Western Ontario and McMaster Universities Osteoarthritis Index score, patient satisfaction score, and Veterans RAND 12 (VR-12) score. All patients had achieved a minimum of 1 year of follow-up at the time of assessment. All P values for significance were set at .05 or lower.

Results

Of 182 patients (average age, 30.4 years), 156 (86%) were available for follow-up with return-to-duty data at an average of 2.8 years (range, 1-6 years). Of the patients, 78% returned to full duty (53%) or returned to duty with restrictions (25%). Outcome scores were available for 101 of 182 patients (55%) with duty rates similar to the total cohort (81% who returned to duty: 58% with no restrictions and 23% with restrictions). Return to duty correlated with improved outcomes compared with those who were medically discharged with respect to the modified Harris Hip Score (68.2 vs 54.5, P < .03), Single Assessment Numeric Evaluation score (48.2 vs 25.3, P < .02), and VR-12 physical (39.7 vs 33.2, P < .05) and VR-12 mental (54.5 vs 43.4, P < .005) scores.

Conclusions

Mini-open arthroscopic-assisted surgery for FAI is successful in returning most service members to duty at short-term follow-up. Return correlates with improved outcome scores, although previously reported minimally clinical important difference and patient acceptable symptomatic state threshold values were not uniformly achieved.

Level of Evidence

Level IV, retrospective case series.

Understanding Painful Hip in Young Adults: A Review Article

A wide number of disorders, including pathologies outside the hip, can cause and refer pain to hip. However, determining the cause of a painful hip can be a major challenge to orthopedic surgeons. Failure to diagnose and appropriately investigate pathologies of the hip in adults may result in delayed management and prolonged patient morbidity. A systematic approach to investigating the etiology of hip pain in adults (e.g., history, careful clinical and radiographic examination), will help identify the majority of clinically important pathologies which can cause hip pain. Conservative treatment and selective use of injection therapies has proven quite successful for the treatment of most causes of hip pain.

Current trends in sport and exercise hip conditions: Intra-articular and extra-articular hip pain, with detailed focus on femoroacetabular impingement (FAI) syndrome

Musculoskeletal conditions, such as hip pain are leading causes of pain and disability. Hip pain is the second most common cause of lower limb musculoskeletal pain, and is commonly seen in active individuals. Hip and groin pain may have intra-articular and extra-articular causes. Femoroacetabular impingement (FAI) syndrome and the associated pathologies are common intra-articular causes of hip and groin pain in active individuals. There are also a number of extra-articular causes of pain, which include musculotendinous conditions, extra-articular impingements and the clinical entities of groin pain described in the Doha agreement. This chapter will describe these, with a detailed focus on FAI syndrome. Specifically, it addresses: 1. What is and what causes FAI syndrome; 2. How do I diagnose FAI syndrome; and 3. What is the evidence-based approach to managing FAI syndrome?

Nonoperative Management Prior to Hip Arthroscopy for Femoroacetabular Impingement Syndrome: An Investigation Into the Utilization and Content of Physical Therapy

BACKGROUND

There has been a significant increase in surgeries for femoroacetabular impingement syndrome in recent years, but little is known about the use of physical therapy prior to surgery.

OBJECTIVES

To investigate the use of physical therapy prior to hip arthroscopy for femoroacetabular impingement syndrome, by assessing the number of visits and use of exercise. A secondary objective was to evaluate whether comorbidities prior to surgery were associated with the use of physical therapy.

METHODS

In this retrospective observational cohort study, eligible participants between the ages of 18 and 50 years undergoing hip arthroscopy between 2004 and 2013 in the Military Health System were included. Patients were categorized based on whether they saw a physical therapist for their hip in the year prior to surgery. For physical therapy patients, dosing variables were identified, including total number of visits and visits that included an exercise therapy procedure code.

RESULTS

Of 1870 participants, 1106 (59.1%) did not see a physical therapist for their hip prior to surgery. For those who did, the median number of visits was 2. Only 220 (11.8%) had 6 or more unique visits with an exercise therapy procedure code. Exercise was coded in 43.4% to 63.0% of the total visits in each individual course of care (mean, 52.3%). There was an association between substance abuse and exercise utilization. No other comorbidities were associated with physical therapy or exercise therapy utilization.

CONCLUSION

Physical therapy was not commonly used before undergoing arthroscopic hip surgery by patients seeking care in the Military Health System. Further research is needed to understand the reasons for poor utilization and better define failed nonoperative management.

LEVEL OF EVIDENCE

Therapy, level 2b. J Orthop Sports Phys Ther 2019;49(8):593-600. Epub 15 May 2019. doi:10.2519/jospt.2019.8581.

Real-Time Assessment of Femoroacetabular Motion Using Radial Gradient Echo Magnetic Resonance Arthrography at 3 Tesla in Routine Clinical Practice: A Pilot Study

PURPOSE

To compare femoroacetabular motion in a series of consecutive symptomatic patients with hip pain throughout the range of motion of the hip using a real-time radial gradient echo (GRE) sequence in addition to the routine hip protocol sequences for magnetic resonance (MR) arthrographic assessment of patients with and without clinical femoroacetabular impingement (FAI) syndrome. In particular, we sought to assess whether the additional dynamic sequence could differentiate between patients with and without a positive physical exam maneuver for FAI syndrome.

METHODS

Patients with hip pain referred for conventional hip MR arthrogram including those with and without a positive physical exam maneuver for FAI syndrome were imaged using routine hip MR arthrogram protocol and an additional real-time radial 2-dimensional GRE acquisition at 3 Tesla in an axial oblique plane with continuous scanning of a 9 mm thick slice through the center of the femoral head-neck axis. Patients who were unable to move through the range of motion were excluded (n = 3). Patients with acetabular dysplasia (defined by a lateral center-edge angle [CEA] of 20°) were also excluded, as were patients had Kellgren and Lawrence scores of > 0. The real-time cine sequence was acquired with the patient actively moving through neutral, flexion, flexion-abduction external-rotation, and flexion-adduction internal rotation (FADIR) positions aiming for 40° of abduction, then 25° of adduction at 80° to 90° flexion. Due to the placement of the coil over the hip, a true FADIR was precluded. Images were evaluated independently by 2 musculoskeletal radiologists measuring the joint space in the anterior, central, and posterior positions at each point during range of motion for femoroacetabular cortical space (FACS). Anterior FACS narrowing was calculated as the ratio of joint space in FADIR:neutral position, with lower ratios indicating greater narrowing. Static metrics including alpha angle, CEA, grade of cartilage loss according the Outerbridge classification, and patient demographics were also recorded.

RESULTS

Twenty-two painful hips in 22 patients (11 males and 11 females) with mean age 36 years (range, 15-67) were included. Twelve patients had a positive physical exam maneuver for FAI syndrome. The time to perform the dynamic sequence was 3 to 6 minutes. Interobserver agreement was strong, with intraclass correlation 0.91 and concordance correlation 0.90. According to results from both readers, patients with impingement on clinical exam had significantly lower anterior FACS ratios compared with those without clinical impingement (reader 1: 0.39 ± 0.10 vs 0.69 ± 0.20, P = .001; reader 2: 0.36 ± 0.07 vs 0.70 ± 0.17, P < .001). Decreased anterior FACS ratio was found to be significantly correlated to increased alpha angle by both readers (reader 1: R = -0.63, P = .002; reader 2: R = -0.67, P = .001) but not significantly correlated to CEA (reader 1: R = 0.13, P = .561; reader 2: R = 0.20, P = .378) or cartilage loss (reader 1: R = 0.03, P = .885; reader 2: R = -0.06, P = .784). Both readers found patients with an anterior FACS ratio of 1/2 to have significantly higher mean alpha angle (reader 1: 62.88 vs 52.79, P = .038; reader 2: 63.50 vs 50.58, P = .006); however, there were no significant differences in cartilage loss (reader 1: P = .133; reader 2: P = .882) or CEA (reader 1: P = .340; reader 2: P = .307).

CONCLUSIONS

A dynamic radial 2-dimensional-GRE sequence can be added to standard hip MR arthrogram protocols in <6 minutes, allowing assessment of dynamic femoroacetabular motion with strong interreader agreement. Patients with impingement on clinical exam had significantly lower anterior FACS ratios between FADIR and neutral positions, compared with those without clinical impingement.

LEVEL OF EVIDENCE

Level III, comparative diagnostic investigation.

Editorial Commentary: What Exactly Is Impingement-Can Dynamic Magnetic Resonance Imaging "See" Impingement in Femoroacetabular Impingement?

The diagnosis of femoroacetabular impingement (FAI) syndrome requires that 3 prerequisites are met. Patient symptoms and physical examination must be combined with imaging to appropriately make the diagnosis. Imaging, including plain radiographs, magnetic resonance imaging (MRI), and computed tomography, should be interpreted in the context of a high prevalence of cam and pincer morphology, in addition to labral injury, in the general population. All images routinely obtained in current clinical practice are 2-dimensional representations of complex 3-dimensional processes. Although computerized modeling can dynamically manipulate femur and pelvis independently in fluoroscopy-, computed tomography-, and/or MRI-based collision detection models, the exact definition of "impingement" eludes the current literature. High-resolution, high magnet strength (minimum 3 Tesla), physiologic and/or biochemical dynamic MRI has the potential to image both soft and osseous tissues, interacting to best define hip impingement.

Preoperative Performance of the PROMIS in Patients Undergoing Hip Arthroscopic Surgery for Femoroacetabular Impingement Syndrome

Background:

The Patient-Reported Outcomes Measurement Information System (PROMIS) is being increasingly evaluated for use in orthopaedic surgery. The performance of the PROMIS in patients undergoing hip preservation surgery is unknown.

Purpose:

To investigate the psychometric performance of the PROMIS compared with legacy patient-reported outcome measures (PROMs) in patients indicated for hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS).

Study Design:

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

Methods:

Data from consecutive patients who underwent primary hip arthroscopic surgery between January and October 2018 for the treatment of FAIS were collected and analyzed. Baseline data, including preoperative PROM scores and demographics, were recorded. PROMs included the PROMIS Physical Function (PF), the Hip Outcome Score (HOS), the modified Harris Hip Score (mHHS), the International Hip Outcome Tool–12 (iHOT-12), and the Veterans RAND 12-item health survey (VR-12). Pearson and Spearman coefficient analyses were used to identify correlations between continuous and noncontinuous variables, respectively. Correlation was defined as excellent (>0.80), very good (0.71-0.80), good (0.61-0.70), fair (0.41-0.60), or poor (0.21-0.40). A multivariate linear regression analysis was used to identify preoperative predictors of having higher preoperative PROMIS scores.

Results:

A total of 197 patients with a mean age and body mass index (BMI) of 32.8 ± 12.6 years and 25.7 ± 5.6 kg/m², respectively, were included in the final analysis. There were no ceiling or floor effects for the PROMIS PF score observed in the study group. With regard to hip-specific measures, PROMIS PF scores demonstrated excellent correlation with HOS–Activities of Daily Living (r = 0.801; P < .001) scores, very good correlation with mHHS (r = 0.721; P < .001) and iHOT-12 (r = 0.722; P < .001) scores, and good correlation with HOS–Sports Specific (r = 0.675; P < .001) scores. With regard to general health–related quality of life (HRQoL) measures, PROMIS PF scores demonstrated very good correlation with VR-12 mental (r = 0.721; P < .001) scores, good correlation with VR-12 physical (r = 0.618; P < .001) scores, and poor correlation with visual analog scale for pain (r = –0.365; P < .001) scores. Patients who reported being physically active were more likely to have a higher preoperative PROMIS score (β = 3.216; P = .004). Lower PROMIS scores were found in patients with a higher BMI (β = –0.236; P = .005) and in female patients (β = –2.608; P = .014).

Conclusion:

In patients with FAIS, the preoperative PROMIS PF scores demonstrated excellent to good correlation with legacy hip-specific instruments as well as with HRQoL measures. No ceiling or floor effects were identified. Notably, of the hip-specific PROMs administered, the PROMIS PF demonstrated the weakest correlation with the HOS–Sports Specific subscale. Physical activity, BMI, and sex were predictors of preoperative PROMIS scores in our patient population.

CAM-type femoroacetabular impingement in male elite junior cross-country skiers and non-athlete controls: a cross-sectional MRI study

Objectives

Cross-country (CC) skiing consists of two main techniques: classic and skating. Hip motion during the skating technique is similar to that in ice skating and is considered a risk factor for femoroacetabular impingement (FAI) in ice hockey players. We aimed to compare the presence of CAM-type FAI in a cohort of elite junior CC (EJCC) skiers with a control group of non-athlete (NA) high school students.

Methods

Observational cohort study: EJCC skiers and NAs were recruited from a sports school and a regular high school, respectively. Baseline demographics and training history were obtained via a questionnaire. Bilateral hip MRI was performed and the alpha angle was measured in three planes. CAM deformity was defined as an alpha angle>55° on at least two MRI planes per hip.

Results

A total of 20 EJCC skiers and 10 NAs participated. All participants were male, aged 16–19 years. Average training volume was 528.10±68.34 hours per year for the EJCC skiers compared with 153.50±57.09 for the NAs (p<0.001). The prevalence of CAM deformity in at least one hip on MRI was 50% in both groups (10 CC skiers and 5 NAs). The average alpha angles were 52.4±6.1° in the EJCC group and 52.5±4.9° in the NA group (p=0.94).

Conclusion

Radiographic evidence of CAM-type FAI was not more common in the CC skiers compared with NAs. The type, rather than volume or intensity of training, maybe a more important risk factor for the development of CAM-type FAI in young athletes.

Hamstring rehabilitation in elite track and field athletes: applying the British Athletics Muscle Injury Classification in clinical practice

Rationale

Hamstring injuries are common in elite sports. Muscle injury classification systems aim to provide a framework for diagnosis. The British Athletics Muscle Injury Classification (BAMIC) describes an MRI classification system with clearly defined, anatomically focused classes based on the site of injury: (a) myofascial, (b) muscle–tendon junction or (c) intratendinous; and the extent of the injury, graded from 0 to 4. However, there are no clinical guidelines that link the specific diagnosis (as above) with a focused rehabilitation plan.

Objective

We present an overview of the general principles of, and rationale for, exercise-based hamstring injury rehabilitation in British Athletics. We describe how British Athletics clinicians use the BAMIC to help manage elite track and field athletes with hamstring injury. Within each class of injury, we discuss four topics: clinical presentation, healing physiology, how we prescribe and progress rehabilitation and how we make the shared decision to return to full training. We recommend a structured and targeted diagnostic and rehabilitation approach to improve outcomes after hamstring injury.

Exercise Therapy for the Management of Femoroacetabular Impingement Syndrome: Preliminary Results of Clinical Responsiveness

OBJECTIVE

To investigate the responsiveness to exercise therapy of patients with femoroacetabular impingement syndrome (FAIS), and to investigate differences in hip function, strength, and morphology between responders versus nonresponders.

METHODS

Patients with FAIS underwent 12 weeks of semi-standardized and progressive exercise therapy. A good therapy outcome (responders) versus a poor therapy outcome (nonresponders) was determined at week 18 with the Global Treatment Outcome questionnaire for hip pain. Hip function was evaluated using the Hip Outcome Score (HOS) activities of daily living (ADL) and Sport at baseline, and at weeks 6, 12, and 18. Hip muscle strength and dynamic pelvic control were evaluated using dynamometry and video analysis, respectively, at baseline, week 12, and week 18. Hip morphology was evaluated with imaging at baseline.

RESULTS

Thirty-one patients (mean age 24 years) were included. Sixteen patients (52%) were responsive and 15 patients (48%) were not responsive to exercise therapy. Only responders improved HOS ADL and HOS Sport by 10 points (95% confidence interval [95% CI] 7, 14; P < 0.001) and by 20 points (95% CI 15, 25; P < 0.001), respectively, and hip abductor strength by 0.27 Nm/kg (95% CI 0.18, 0.36; P < 0.001). The prevalence of patients showing good dynamic pelvic control only increased in responders (44%; P = 0.029). The prevalence of severe cam morphology was higher in nonresponders than in responders (40% versus 6%; P = 0.037).

CONCLUSION

Half of patients with FAIS benefit from exercise therapy in the short term. Responsiveness to hip abductor strength and dynamic pelvic control improvements is associated with a good therapy outcome, whereas the presence of severe cam morphology is associated with a poor therapy outcome.

Editorial Commentary: The Gain in Pain After Hip Arthroscopic Surgery: What Is Clinically Relevant, and Is Pain Related to Function in Patients With Femoroacetabular Impingement Syndrome?

Hip arthroscopic surgery improves patient-reported outcomes in patients with femoroacetabular impingement syndrome and/or hip chondropathy. The minimal clinically important change on a pain visual analog scale has now been calculated in this patient group, and the pain level 1 year after surgery has been related to function. Next step: identifying what causes pain and decreased function 1 year after surgery.

Minimal Clinically Important Difference and Substantial Clinical Benefit Values for a Pain Visual Analog Scale After Hip Arthroscopy

PURPOSE

To define minimal clinically important difference (MCID) and substantial clinical benefit (SCB) values for a pain visual analog scale (VAS) in patients undergoing hip arthroscopy for femoroacetabular impingement or chondrolabral pathology.

METHODS

This was a retrospective review of prospective collected data on patients having hip arthroscopy for femoroacetabular impingement and/or chondrolabral pathology. On initial assessment and follow-up between 335 and 395 days postsurgery, subjects completed a pain VAS and categorical self-rating of function. MCID was calculated using one-half the standard deviation (SD) of the change in 1-year pain VAS values. Receiver operator characteristic analysis was performed to determine SCB values. A change in SCB value was determined based on change in categorical self-rating of function to create "improved" and "not improved" groups. Absolute postoperative SCB scores were calculated to determine scores that would be associated with "normal" or "abnormal" function ratings.

RESULTS

Of 1,034 eligible patients, 733 (71%) met the inclusion criteria, with 537 (73%) women and 196 (27%) men having a mean age of 35.3 years (SD 13). At a mean of 352 (SD 21) days postsurgery, 536 (73%) were in the improved group and 197 (27%) in the not improved group. MCID was -15.0 mm. A change of -22.7 mm on the pain VAS was able to identify those that improved with high sensitivity (0.74) and specificity (0.63). Values of ≤10.4 mm and ≥29.0 mm were cutoffs identifying subjects that rated their function as normal or abnormal, respectively, with high sensitivity (0.79 and 0.76) and specificity (0.88 and 0.76).

CONCLUSIONS

This study provides surgeons with information to help interpret pain VAS values at a follow-up period ranging from 335 to 395 days with MCID and SCB values of -15.0 mm and -22.7 mm, respectively. Additionally, a patient who assesses a pain level at ≤10.4 mm is likely to have a normal rating of function, whereas a patient who assesses a pain level at ≥29.0 mm is likely to have an abnormal rating of function.

LEVEL OF EVIDENCE

III, retrospective comparative study.

High relative reliability and responsiveness of the forgotten joint score-12 in patients with femoroacetabular impingement undergoing hip arthroscopic treatment. A prospective survey-based study

The forgotten joint score-12 (FJS-12) may be an advantageous questionnaire in young patients with high hip function and a low level of pain. We investigated the reliability and the responsiveness of the FJS-12 in patients with femoroacetabular impingement undergoing hip arthroscopic treatment. Fifty patients were included in the reliability study and 34 patients were included in the responsiveness study. Test-retest reliability was assessed with intraclass correlation coefficient (ICC), standard error of measurement (SEM) and minimal detectable change (MDC). Responsiveness was assessed from testing correlations between the FJS-12 and the Copenhagen Hip and Groin Outcome Score (HAGOS) of the change score, effect size (ES) and standardized response mean (SRM). Floor and ceiling effect were defined as present if the number of patients obtaining the maximum (100) and minimum score (0) exceeded 15%. The relative reliability was high (ICC = 0.9, 95% CI: 0.8-0.9) and the absolute reliability was low (SEM = 11, MDC_individual = 32, MDC_group = 4.5). The responsiveness was high, and the change score was highly correlated with the subscale 'pain' from the HAGOS and moderately correlated with the subscale 'ADL'. Furthermore, the FJS-12 exceeded or equalled the HAGOS subscales in ES and SRM. Below 15% of the patients scored the maximum or minimum score. The FJS-12 has high reliability, high responsiveness to change and shows no floor or ceiling effect.

Hip Function 6 to 10 Months After Arthroscopic Surgery: A Cross-sectional Comparison of Subjective and Objective Hip Function, Including Performance-Based Measures, in Patients Versus Controls

Background:

Little is known about hip-related function, mobility, and performance in patients after hip arthroscopic surgery (HA) during the time that return to sports can be expected.

Purpose:

To evaluate measures of subjective and objective hip function 6 to 10 months after HA in patients compared with healthy controls and to compare objective function in the HA group between the operated and nonoperated hips.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 33 patients who had undergone HA (mean, 8.1 ± 2.6 months postoperatively) and 33 healthy participants matched on sex, age, and activity level were compared regarding subjective hip function (Copenhagen Hip and Groin Outcome Score [HAGOS]) and objective function including hip range of motion (ROM; flexion, internal rotation, and external rotation), isometric hip muscle strength (adduction, abduction, flexion, internal rotation, and external rotation), and performance-based measures: the Y Balance Test (YBT), medial and lateral triple-hop test, and Illinois agility test. Group differences were analyzed using independent-samples t tests. Paired-samples t tests were used for a comparison of the operated and nonoperated hips. Standard effect sizes (Cohen d) were provided for all outcomes.

Results:

The HA group reported worse subjective hip function than the control group (HAGOS subscores: d = –0.7 to –2.1; P ≤ .004). Objective measures of hip ROM (d = –0.5 to –1.1; P ≤ .048), hip flexion strength (d = –0.5; P = .043), and posteromedial reach of the YBT (d = –0.5; P = .043) were also reduced in the HA group, although there were no significant differences between groups regarding the remaining objective measures (d = –0.1 to –0.4; P ≥ .102 to .534). The only significant difference between the operated and nonoperated hips in the HA group was reduced passive hip flexion (d = –0.4; P = .045).

Conclusion:

Patients who had undergone HA demonstrated reduced subjective hip function compared with controls 6 to 10 months after surgery, when return to sports can be expected. While most objective strength and performance test results were comparable between the HA and control groups at 6 to 10 months after surgery, the HA group presented with impairments related to hip mobility and hip flexion strength. No consistent pattern of impairments was found in operated hips compared with nonoperated hips.

Increased pelvic mobility and altered hip muscles contraction patterns: two-year follow-up cam-FAIS corrective surgery

Femoroacetabular impingement syndrome (FAIS) surgery can produce improvements in function and patient satisfaction; however, data on muscle assessment and kinematics of high mobility tasks of post-operative patients is limited. The purpose of this study was to evaluate kinematics and muscle activity during a deep squat task, as well as muscle strength in a 2-year follow-up FAIS corrective surgery. Eleven cam morphology patients underwent motion and electromyography capture while performing a squat task prior and 2-years after osteochondroplasty and were BMI-, age- and sex-matched to 11 healthy control (CTRL) participants. Isometric muscle strength, flexibility and patient-reported outcome measures (PROMs) were also evaluated. Post-operative FAIS was significantly weaker during hip flexion (23%) and hip flexion-with-abduction (25%) movements when compared with CTRL, no improvements in squat depth were observed. However, post-operative FAIS increased the pelvic range of motion during the squat descent (P = 0.016) and ascent (P = 0.047). They had greater peak activity for the semitendinosus and total muscle activity for the gluteus medius, but decreased peak activity for the glutei and rectus femoris during squat descent; greater total muscle activity for the tensor fascia latae was observed during squat ascent (P = 0.005). Although not improving squat depth, post-operative patients increased pelvic ROM and showed positive PROMs. The muscle weakness associated with hip flexion and flexion-with-abduction observed at the follow-up can be associated with the alterations in the muscle activity and neuromuscular patterns. Rehabilitation programs should focus on increasing pelvis and hip muscles flexibility and strength.

The association between specific sports activities and sport performance following hip arthroscopy for femoroacetabular impingement syndrome: A secondary analysis of a cross-sectional cohort study including 184 athletes

The main purpose of this secondary analysis was to compare the proportion of athletes with moderate-to-extreme difficulties in eight specific sport activities in athletes with optimal versus impaired sport performance after a hip arthroscopy for femoroacetabular impingement syndrome. Subjects were identified in a nationwide registry and invited to answer a return to sport and performance questionnaire, and the Copenhagen Hip and Groin Outcome Score Sport subscale investigating difficulties in eight specific sports activities (HAGOS sport items) as; none, mild, moderate, severe or extreme. Subjects were divided into two groups based on sport performance (optimal or impaired). The proportion of athletes with none-to-mild versus moderate-to-extreme difficulties in the eight specific sport activities was compared between groups. The association between difficulties in sport activities and sport performance were investigated using logistic regression analysis. One hundred and eighty-four athletes (31 athletes with optimal and 153 athletes with impaired sport performance) were included at a mean follow-up of 33.1 ± 16.3 months. Up to six athletes (<20%) with optimal sport performance had moderate-to-extreme difficulties in sport activities. Contrary, 43–108 athletes (28.1–70.6%) with impaired performance had moderate-to-extreme difficulties in sport activities. Furthermore, moderate-to-extreme difficulties in HAGOS sport items: ‘running as fast as you can’ and ‘kicking, skating etc.’ increased the odds (14.7 and 6.1 times, respectively) of having impaired sport performance. Many athletes with impaired sport performance reported moderate-to-extreme difficulties in sport activities, specifically moderate-to-extreme difficulties in ‘running as fast as you can’ and ‘kicking, skating etc.’ were associated with patients having impaired sport performance.

Editorial Commentary: If You Can't See It, You Can't Treat It: Proper Hip Radiographic Views Are Critical

Hip arthroscopy has become a common surgical treatment for femoroacetabular impingement syndrome and hip labral tears. In addition to being a complex procedure with a steep learning curve, understanding the required imaging to provide a comprehensive view of femoral cam deformities can be challenging. Because of the 3-dimensional anatomy of the hip joint, 2-dimensional imaging with plain radiographs may miss areas of pathomorphology that are not in the plane of the specific radiographic view.

Do Your Routine Radiographs to Diagnose Cam Femoroacetabular Impingement Visualize the Region of the Femoral Head-Neck Junction You Intended?

PURPOSE

To use computer models and image analysis to identify the position on the head-neck junction visualized in 10 radiographic views used to quantify cam morphology.

METHODS

We generated 97 surface models of the proximal femur from computed tomography scans of 59 control femurs and 38 femurs with cam morphology-a flattening or convexity at the femoral head-neck junction. Each model was transformed to a position that represents the anteroposterior, Meyer lateral, 45° Dunn, modified false-profile, Espié frog-leg, modified 45° Dunn, frog-leg lateral, cross-table, 90° Dunn, and false-profile views. The position on the head-neck junction visualized from each view was identified on the surfaces. This position was then quantified by a clock face generated on the plane of the head-neck junction, in which the 12-o'clock position indicated the superior head-neck junction and the 3-o'clock position indicated the anterior head-neck junction. The mean visualized clock-face position was calculated for all subjects. Analysis was repeated to account for variability in femoral version. A general linear model with repeated measures was used to compare each radiographic view and anteversion angle.

RESULTS

Each radiographic view provided visualization of the mean clock-face position as follows: anteroposterior view, 12:01; Meyer lateral view, 1:08; 45° Dunn view, 1:40; modified false-profile view, 2:01; Espié frog-leg view, 2:14; modified 45° Dunn view, 2:35; frog-leg lateral view, 2:45; cross-table view, 3:00; 90° Dunn view, 3:13; and false-profile view, 3:44. Each view visualized a different position on the clock face (all P < .001). Increasing simulated femoral anteversion by 10° changed the visualized position of the head-neck junction to a more clockwise position (range, 0:07 to 0:29; all P < .001), whereas decreasing anteversion by 10° visualized a more counterclockwise position (range, -0:23 to -0:08; all P < .001).

CONCLUSIONS

Ten common radiographic views used to identify cam morphology visualized different clock-face positions of the head-neck junction. Our data will help clinicians to understand the position of the head-neck junction visualized for each radiographic view and make educated decisions in the selection of radiographs acquired in the clinic.

CLINICAL RELEVANCE

Our findings will aid clinicians in choosing a set of radiographs to capture cam morphology in the assessment of patients with hip pain.

Quality Assessment of Prospective Cohort Studies Evaluating Arthroscopic Treatment for Femoroacetabular Impingement Syndrome: A Systematic Review

Background

Femoroacetabular impingement (FAI) syndrome is a cause of pain and reduced range of motion in the hip joint. Given the limited number of randomized controlled trials, prospective cohort studies constitute the dominant part of the available prospective evidence evaluating relevant clinical outcomes after arthroscopic hip surgery for FAI.

Purpose

To assess the methodological quality of prospective cohort studies evaluating arthroscopic surgery for FAI and to determine whether there has been an improvement in methodological quality over time.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic literature search was performed in PubMed, Embase (OvidSP), and the Cochrane Library. Included studies were clinical prospective cohort studies of primary arthroscopic surgery for cam and/or pincer morphology FAI. Methodological quality was assessed with the Methodological Index for Non-randomized Studies (MINORS). The mean MINORS score for studies published during the first 5 years of the period was compared with those published during the last 5 years to evaluate methodological improvement over time. The methodological quality of randomized controlled trials was also assessed with the Coleman Methodology Score.

Results

The search yielded 53 studies. There were 34 noncomparative studies, 15 nonrandomized comparative studies, and 4 randomized controlled trials. The included studies were published between 2008 and 2017. The mean ± SD MINORS score for noncomparative and comparative studies was 10.4 ± 1.4 of 16 possible and 18.7 ± 2.0 of 24 possible, respectively. The mean Coleman Methodology Score for randomized controlled trials was 79.0 ± 7.0 of 100 possible.

Conclusion

The methodological quality of prospective cohort studies evaluating arthroscopic surgery for FAI is moderate for comparative and noncomparative studies. Common areas for improvement include unbiased assessment of study endpoints and prospective sample-size calculations. Despite an increase in the number of published studies, an improvement in methodological quality over time was not observed.

Retraining in a Female Elite Rower with Persistent Symptoms Post-Arthroscopy for Femoroacetabular Impingement Syndrome: A Proof-of-Concept Case Report

Athletes with femoroacetabular impingement syndrome (FAIS) managed arthroscopically do not always return to sport. Inability to control back/pelvis, hip and lower limb movements may contribute to the onset and recurrence of symptoms. Our hypothesis is that results from a battery of cognitive movement control tests can inform a cognitive movement control (neuromuscular) retraining programme for improving the clinical presentation and quality of life in an athlete with FAIS. This case report presents a female elite rower with persistent left-sided anterior hip pain, four years post-arthroscopic surgery for FAIS, whose symptoms failed to respond to conventional physical therapy. Hip and groin outcome score (HAGOS), passive and active hip flexion range of motion (ROM) workload (time training on water), hip and pelvic kinematics (3-D motion analysis) and electromyography during a seated hip flexion movement control test, and a movement control test battery to identify movement control impairments (The Foundation Matrix), were assessed pre-intervention (week 0) and immediately post-intervention (week 16). Impaired movement control was targeted in a tailored 16-week cognitive movement control retraining exercise program. All measures improved: HAGOS (all 6 sub-scales); symptoms (61/100 pre-training to 96/100 post-training); physical activities participation (13/100 to 75/100); and active hip flexion ROM increased (78 to 116 and 98 to 118 degrees, respectively); workload increased from 4 to 18 h/week; and movement control impairment reduced (25/50 to 9/50). Pelvic motion on kinematic analysis were altered, and delayed activation onset of tensor fascia latae and rectus femoris muscles reduced. This proof-of-concept case report supports the hypothesis that cognitive movement control tests can inform a targeted cognitive movement control retraining program to improve symptoms, function and quality of life, in an elite rower with persistent hip pain. This training offers an alternative approach to conventional physical therapy, which has failed to restore function in FAIS, and the present study illustrates how specific cognitive movement control assessment can direct individual training programmes.

Trends in Hip Arthroscopic Labral Repair: An American Board of Orthopaedic Surgery Database Study

PURPOSE

The purpose of this study is to evaluate the trends in labral repair in American Board of Orthopaedic Surgery Part II candidates performing hip arthroscopy.

METHODS

Candidates who performed arthroscopic hip surgery between 2011 and 2015 during their American Board of Orthopaedic Surgery Part II board collection period were identified using Current Procedural Terminology codes (29860, 29861, 29862, 29863, 29914, 29915, 29916). The proportion of hip arthroscopy cases including labral repair (Current Procedural Terminology code 29916) were calculated for each year and analyzed by fellowship training experience. Trends in labral repair utilization were calculated using univariate and regression analyses, with significance set at P < .05.

RESULTS

During the study period, 1,606 hip labral repair cases were performed, with a 35% increase in utilization between 2011 and 2015. Overall, labral repair was performed in 64.8% (1,606/2,480) of hip arthroscopy cases, with a significant increase between 2011 and 2015 (47.4% vs 79.2%; P < .001). Of the hip arthroscopy cases including labral repair, 80.4% (1,291/1,606) were performed by candidates with sports medicine fellowship training. The proportion of hip arthroscopy cases including labral repair was highest for surgeons with sports medicine fellowship training compared with those without sports medicine fellowship training (66.1% vs 59.8%; P = .007). Candidates with sports medicine training performing at least 1 labral repair each year increased from 68% to 89% over the study period (P = .0007). The average number of labral repairs per candidate increased significantly over the duration of the study period (P = .0072).

CONCLUSIONS

Labral repair utilization during hip arthroscopy procedures nearly doubled from 2011 to 2015 for American Board of Orthopaedic Surgery Part II candidates, reflecting a significant change in practice. Current data suggest that nearly 80% of hip arthroscopy procedures include labral repair. These trends may reflect the current practice patterns at academic institutions with sports medicine fellowships.

Patients With Unilateral Femoroacetabular Impingement Syndrome Have Asymmetrical Hip Muscle Cross-Sectional Area and Compensatory Muscle Changes Associated With Preoperative Pain Level

PURPOSE

To compare the symptomatic hip muscle cross-sectional area (CSA) in patients with unilateral femoroacetabular impingement syndrome (FAIS) with the asymptomatic-side hip muscle CSA and to determine whether correlations exist between the hip muscle CSA and preoperative pain level, preoperative symptom duration, and postoperative function.

METHODS

We performed a retrospective review of magnetic resonance imaging data of patients who underwent hip arthroscopy from January 2012 through June 2015 for the treatment of unilateral FAIS and who had a minimum of 2 years' follow-up after hip arthroscopy for FAIS. A picture archiving and communication system workstation with an embedded region-of-interest tool was used to measure the muscle CSA of both the symptomatic and asymptomatic sides in FAIS patients. One-way repeated-measures analyses of variance were used to determine differences between symptomatic and asymptomatic hip muscle CSAs. Spearman rank correlations were used to determine relations between the symptomatic-side hip muscle CSA and preoperative pain level, preoperative symptom duration, and multiple validated patient-reported outcomes to quantify the level of function.

RESULTS

A total of 50 patients met the inclusion criteria and were analyzed. The mean age of the patients was 34.22 ± 14.12 years, and 64% were women. Specific muscles of the symptomatic hip displaying significantly decreased CSAs compared with the asymptomatic hip included the gluteus maximus (P = .007), gluteus minimus (P = .022), and rectus femoris (P = .028). The tensor fascia lata (ρ = 0.358; P = .011), pectineus (ρ = 0.369, P = .008), adductor longus (ρ = 0.286, P = .044), and obturator externus (ρ = 0.339, P = .016) showed a moderate positive correlation with preoperative pain level on a visual analog scale in unilateral FAIS patients. No associations were found between the symptomatic-side hip muscle CSA in patients with unilateral FAIS and symptom duration or patient-reported function.

CONCLUSIONS

Patients with unilateral FAIS have a significantly decreased muscle CSA in the symptomatic hip compared with the asymptomatic hip. The symptomatic-side hip muscle CSA was correlated with the preoperative pain level on a visual analog scale. The association between the muscle CSA and preoperative pain level may represent a compensatory change in muscle function around the hip joint in patients with unilateral FAIS.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.