Trends in femoroacetabular impingement research over 11 years

What can we learn from surveys? A systematic review of survey studies addressing femoroacetabular impingement syndrome

The purpose of this study was to systematically review the methodology, response rate and quality of survey studies related to femoroacetabular impingement (FAI) syndrome. A search was conducted on three databases (PubMed, EMBASE, MEDLINE) for relevant studies from database inception to 27 January 2020. Data extracted included study and survey characteristics, as well as response rates. The quality of the included studies was also assessed using a previously published quality assessment tool. Data were analysed with means, ranges, standard deviations, 95% confidence intervals and bivariate analysis. Eleven studies (13 surveys) were included in this review out of a total of 1608 initial titles found. Surveys were most often administered via the Internet (72%) to orthopaedic surgeons (54%). The mean response rate was 70.4%. The mean quality score was moderate 13.3/24 (SD ±4.3). The criterion that most often scored high was ‘clearly defined purpose and objectives’ (11/11). The most common survey topic investigated surgeons’ knowledge regarding FAI diagnosis and management (n = 7). In addition, bivariate analysis between quality score and response rate showed no significant correlation (Spearman’s rho = −0.090, P = 0.85). Overall, survey studies related to FAI syndrome most often use Internet-based methods to administer surveys. The most common target audience is orthopaedic surgeons. The topics of the surveys most often revolve around orthopaedic surgeons’ knowledge and opinions relating to the diagnosis and management of FAI syndrome. The response rate is high in patient surveys and lower in larger surgeon surveys. Overall, the studies are of moderate quality.

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.

Prevalence of femoroacetabular impingement and effect of training frequency on aetiology in paediatric football players

PURPOSE:

The aim of this study was to determine the prevalence of asymptomatic radiographic findings of femoroacetabular impingement (FAI) in paediatric football players in different age groups and to investigate aetiological factors.

METHODS:

Paediatric male athletes between 10 and 17 years of age from 8 soccer teams were recruited. In addition to an annual control check-up, anteroposterior pelvis and frog-leg radiographs as well as the curriculum vitae of the athletes, their injuries, and real-time complaints were recorded. The alpha angle, lateral centre-edge angle, Tönnis angle, and collodiaphyseal angle were measured and morphological abnormalities were noted.

RESULTS:

There were 214 male football players with a mean age of 13.4 ± 3.2 years included in the study. In the morphological analysis of hips, there was FAI in 30% of the athletes. In the analysis of FAI prevalence in 3 subgroups based on age (Group 1: 10-12 years [ n = 25], Group 2: 13-15 years [ n = 104], Group 3: 16-17 years [ n = 85]), there was 0% FAI in Group 1, 19.1% in Group 2 and 60% in Group 3. In the analysis of aetiological factors, there was no significant difference between the right and left hips of players regarding alpha angles and FAI prevalence. However, the prevalence of FAI was higher in players who had been playing football for 3 years or more and who had been training for 12.5 hours/week or more.

CONCLUSION:

Training for 12.5 hours or more per week in paediatric football players doubled the risk development of FAI morphology.

Authorship in the field of femoroacetabular impingement: an analysis of journal publications

PURPOSE

This review provides a bibliometric analysis of the contributors to the field of FAI research.

METHODS

A comprehensive search of three databases (MEDLINE, EMBASE, and PubMed) was performed to identify all clinical research articles on the topic of FAI (from inception to 2015). Cadaveric and animal studies were excluded. Study characteristics including authors, residing country of corresponding author, and journal were abstracted from the respective databases.

RESULTS

In total, 1073 articles were included in this review. There were a total of 5471 different authors who contributed to the field of FAI research, 28.3 % of whom were only published in one article. The top 20 authors were associated with over half of all publications, and research studies were typically performed in their countries of residence. The greatest proportion of FAI-related articles was published in the Journal of Arthroscopy and Clinical Orthopaedics and Related Research.

CONCLUSIONS

The number of authors contributing to FAI research is increasing, suggesting not only increasing prevalence of FAI treatment among orthopaedic surgeons but also increasing interest among hip arthroscopists in furthering understanding regarding the diagnosis and management of the condition. The number of publications produced by the top 20 authors (and their affiliated countries: USA, Switzerland, Canada, and the UK) is expected to contribute to a majority of future publications. Current trends suggest that the quality of evidence will continue to improve in the near future, as large-scale, collaborative studies are currently underway.

LEVEL OF EVIDENCE

Retrospective study, Level IV.

Sources and quality of literature addressing femoroacetabular impingement: a scoping review 2011-2015

A systematic review was performed to explore the current trends over the last 5 years in femoroacetabular impingement (FAI) literature and compare the quality and sources of publications in the literature to that published previously. We identified 1066 relevant studies including 186,572 patients. The number of publications increased during the reviewed time period with the most dramatic increase from 2011 to 2013. Seventy-three percent (N = 786) of all studies were of levels 4 and 5 quality evidence. The percent of publications which were levels 1, 2 and 3 increased by almost twofold from 16.1 % (N = 26) to 28.7 % (N = 51) between 2011 and 2015. In comparison to previous work, there has been 3.5-fold increase in the number of publications over the past 5 years with a shift towards improving the level of evidence available guiding the arthroscopic management of FAI.

LEVEL OF EVIDENCE

IV-Systematic Review.

Overdiagnosing of femoroacetabular impingement: correlation between clinical presentation and computed tomography in symptomatic patients

Objective

To correlate the angles between the acetabulum and the proximal femur in symptomatic patients with femoroacetabular impingement (FAI), using computed tomography (CT).

Methods

We retrospectively evaluated 103 hips from 103 patients, using multislice CT to measure the acetabular age, acetabular version (in its supraequatorial portion and in its middle third), femoral neck version, cervical-diaphyseal and alpha angles and the acetabular depth. For the statistical analysis, we used the Pearson correlation coefficient.

Results

There were inverse correlations between the following angles: (1) acetabular coverage versus alpha angle (p = 0.019); (2) acetabular version (supraequatorial) versus alpha angle (p = 0.049). For patients with femoral anteversion lower than 15 degrees: (1) acetabular version (supraequatorial) versus alpha angle (p = 0.026); (2) acetabular version (middle third) versus alpha angle (p = 0.02). For patients with acetabular version (supraequatorial) lower than 10 degrees: (1) acetabular version (supraequatorial) versus alpha angle (p = 0.004); (2) acetabular version (middle third) versus alpha angle (p = 0.009).

Conclusion

There was a statistically significant inverse correlation between the acetabular version and alpha angles (the smaller the acetabular anteversion angle was, the larger the alpha angle was) in symptomatic patients, thus supporting the hypothesis that FAI occurs when cam and pincer findings due to acetabular retroversion are seen simultaneously, and that the latter alone does not cause FAI, which leads to overdiagnosis in these cases.

New perspectives on femoroacetabular impingement syndrome

Femoroacetabular impingement (FAI) is characterized by an abnormality in the shape of the femoral head-neck or acetabulum that results in impingement between these two structures. Arthroscopic treatment has become the preferred method of management of FAI owing to its minimally invasive approach. Surgical correction involves resection of impinging osseous structures as well as concurrent management of the associated chondral and labral pathology. Research from the past 5 years has shown that repair of the labrum results in a better anatomic correction and improved outcomes compared with labral debridement. Research is underway to improve cartilage assessment by using innovative imaging techniques and biochemical tests to inform predictions of prognosis. Several ongoing randomized controlled trials, including the Femoroacetabular Impingement Trial (FAIT) and the Femoroacetabular Impingement Randomized Controlled Trial (FIRST), will provide critical information regarding the diagnosis, management and prognosis of patients undergoing arthroscopic management of FAI.

Femoro-acetabular impingement clinical research: is a composite outcome the answer?

Femoro-acetabular impingement (FAI) is increasingly recognized as an important cause of hip pain in the young adult. However, the methods of evaluating the efficacy of surgical intervention are often not validated and/or inconsistently reported. Important clinical, gait, radiographic and biomarker outcomes are discussed. This article (1) presents the rationale for considering a composite outcome for FAI patients; (2) examines a variety of important end points currently used to evaluate FAI surgery; (3) discusses a strategy to generate a composite outcome by combining these end points; and (4) highlights the challenges and current areas of controversy that such an approach to evaluating symptomatic FAI patients may present.

Physical examination tests for hip dysfunction and injury

BACKGROUND

Physical examination tests for hip dysfunction and injury of the strongest diagnostic accuracy were identified in a recent systematic review with meta-analysis in BJSM. These tests are described in this article.

DISCUSSION

A detailed description of the various different tests is given, with photographs for each test procedure. Diagnostic interpretation of each test requires careful consideration, with special attention to specific variables such as test performance and patient population.

Methodological quality of systematic reviews addressing femoroacetabular impingement

PURPOSE

As the body of literature on femoroacetabular impingement (FAI) continues to grow, clinicians turn to systematic reviews to remain current with the best available evidence. The quality of systematic reviews in the FAI literature is currently unknown. The goal of this study was to assess the quality of the reporting of systematic reviews addressing FAI over the last 11 years (2003-2014) and to identify the specific methodological shortcomings and strengths.

METHODS

A search of the electronic databases, MEDLINE, EMBASE and PubMed, was performed to identify relevant systematic reviews. Methodological quality was assessed by two reviewers using the revised assessment of multiple systematic reviews (R-AMSTAR) scoring tool. An intraclass correlation coefficient (ICC) with 95 % confidence intervals (CI) was used to determine agreement between reviewers on R-AMSTAR quality scores.

RESULTS

A total of 22 systematic reviews were assessed for methodological quality. The mean consensus R-AMSTAR score across all studies was 26.7 out of 40.0, indicating fair methodological quality. An ICC of 0.931, 95 % CI 0.843-0.971 indicated excellent agreement between reviewers during the scoring process.

CONCLUSIONS

The systematic reviews addressing FAI are generally of fair methodological quality. Use of tools such as the R-AMSTAR score or PRISMA guidelines while designing future systematic reviews can assist in eliminating methodological shortcomings identified in this review. These shortcomings need to be kept in mind by clinicians when applying the current literature to their patient populations and making treatment decisions. Systematic reviews of highest methodological quality should be used by clinicians when possible to answer clinical questions.

What clinimetric evidence exists for using hip-specific patient-reported outcome measures in pediatric hip impingement?

BACKGROUND

Patient-reported outcomes (PROs) are an increasingly popular research tool used to evaluate the outcomes of surgical intervention. If applied appropriately, they can be useful both for disease monitoring and as a method of assessing the efficacy of treatment. Many disorders can lead to impingement in children and adolescents, but it is not clear if any PROs have been validated to evaluate outcomes in these populations.

QUESTIONS/PURPOSES

We performed a systematic review of the literature to answer the following research questions: (1) Which hip-specific PROs are used in pediatric populations with impingement? (2) What clinimetric evidence exists for the use of these specific PROs in this population?

METHODS

We performed two systematic searches of three databases (Medline, EMBASE, and Ovid All EBM Reviews). The first search aimed to identify specific PROs that have been applied to pediatric impingement populations. The second search aimed to find clinimetric evaluations of the PROs from the first search in this population.

RESULTS

We found six hip-specific PROs applied in pediatric impingement: Harris Hip Score, modified Harris Hip Score, Iowa Hip Score, Merle d'Aubigné Hip Score, Hip Outcome Score, and Non-arthritic Hip Score. However, we found no papers validating any of these PROs in this population. Furthermore, we found no papers validating any of these PROs in any pediatric population.

CONCLUSIONS

A number of adult PROs have been applied in pediatric impingement disorders without evidence of validation in any pediatric population. Further work to develop and validate a hip-specific pediatric PRO is required.

Clinical outcome scores for arthroscopic femoral osteochondroplasty in femoroacetabular impingement: a quantitative systematic review

BACKGROUND AND AIMS

Femoroacetabular impingement is the abnormal contact of the proximal femur and acetabulum during motion. It causes hip pain and joint degeneration in young patients. This systematic review aims to clarify the clinical effect of arthroscopic femoral osteochondroplasty for cam lesions and to review the available literature for the general medical readership, including providers of primary and secondary care.

METHODS AND RESULTS

Electronic databases were searched for studies of arthroscopic femoral osteochondroplasty in primary femoroacetabular impingement. A total of 2618 article titles, 242 abstracts and 33 full text articles were considered. Ultimately nine studies with clinical outcome scores met the inclusion criteria and were included in the qualitative systematic review. Six studies were suitable for meta-analysis using an inverse variance, random effects model (RevMan software). In the nine studies, improvements were seen in Western Ontario and McMaster Universities Osteoarthritis index, Non-arthritic Hip Score and Modified Harris Hip Scores. Across the six studies suitable for meta-analysis (537 patients), a 24-point weighted mean improvement in Non-arthritic hip score was seen. This yielded a large overall effect size of 1.6.

CONCLUSION

Arthroscopic femoral osteochondroplasty appears to be a beneficial treatment for primary femoroacetabular impingement, with a large effect size seen across six eligible studies.

Evaluation of the alpha angle in asymptomatic adult hip joints: analysis of 994 hips

INTRODUCTION

Numerous studies on cam femoroacetabular impingement (FAI) causing osteoarthritis have been conducted in Western populations, but not in Asian populations. The alpha angle in cam type FAI can be measured by routine hip AP and axial radiographs. The purpose of this study was to determine the range of alpha angles in an asymptomatic Asian cohort.

MATERIALS AND METHODS

We performed a retrospective examination on 500 asymptomatic Asian adults (1000 hips) who underwent simultaneous spine MRI and hip coronal survey MRI for evaluation of back pain from December 2009 to March 2010. The alpha angle was measured on anteroposterior (AP) pelvic survey images. According to inclusion criteria, 372 hips of 186 men and 622 hips of 311 women were analysed.

RESULTS

The mean alpha angles for men and women were 50.61° ± 7.61° and 49.82° ± 4.14°, respectively with no statistically significant differences (p = 0.063). Alpha angles of the two age groups (≥50 years old and <50 years old) were similar in both genders: 49.90° ± 6.88° versus 51.40° ± 8.30° in men (p = 0.060), and 50.61° ± 7.61° versus 49.82° ± 4.14° in women (p = 0.71). The frequency of pathologic alpha angle of men and women was 0.5% and 3.1%, respectively.

CONCLUSIONS

After review of 994 asymptomatic adult hips, we found neither gender-specific nor age-specific differences in the alpha angle. The frequency of the pathological range of the alpha angle was notably rare, as compared to those of Western countries. We assume that these findings could be related to a low prevalence of FAI and idiopathic osteoarthritis of the hip in the Asian population.

Reports of magnetic resonance images of the hip in patients with femoroacetabular impingement: is useful information provided to the orthopedic surgeon?

OBJECTIVE

The aim of this study was twofold: (1) To evaluate the quality of radiology reports of MR imaging/arthrography (MRI/MRA) of the hip performed on symptomatic young adults with suspected femoroacetabular impingement (FAI); and (2) to assess if MRI/MRA reports provide relevant information for surgical decision-making.

MATERIALS AND METHODS

We evaluated 110 MRI/MRA reports provided by 73 radiologists from 42 institutions. The images were requested preoperatively in young adults who underwent hip-preserving surgery for treatment of FAI. The quality of reports was graded using Lee's method by two independent observers. The description of seven characteristics of the hip joint was scrutinized in order to assess if the reports contained relevant information for surgical decision-making.

RESULTS

The quality of reports was Grade IIA in two cases (1.8 %), IIB in six (5.5 %), III in 60 (54.5 %), and IV in 42 (38.2 %). Relevant hip characteristics for the study of FAI were reported as follows: acetabular labrum (88.1 %), cartilage characteristics (69 %), morphology of the femoral head-neck junction (34.5 %), acetabular version (6.3 %), acetabular coverage (20.9 %), soft tissues description (82.7 %), and presence of bone marrow edema (80.9 %). The vast majority (91.8 %) of the reports described five or less relevant FAI characteristics.

CONCLUSIONS

Most of the radiology reports of MRI/MRA of the hip performed on symptomatic young adults with FAI were of the highest quality. However, some characteristics believed to be important for surgical decision-making in this particular group of patients were frequently not described. The inclusion of these hip joint characteristics in the radiology reports may improve the usefulness of the information provided to the orthopedic surgeon.

Sources and quality of literature addressing femoroacetabular impingement

PURPOSE

In the last 5 years, there has been an increasing interest in the concepts, pathoanatomy, and management of femoroacetabular impingement (FAI). The aim of this study was to determine the trends in FAI literature with specific emphasis on the quality and source of publications in the literature.

METHODS

A systematic review of two electronic databases (MEDLINE, EMBASE) was conducted to identify FAI-related publications from 2005 to 2010. Studies were included if they were published in peer-review journals and were written in English. Abstracted data included year of publication, study design, type of study, level of evidence, number of patients and hips, gender, weighted mean age of patients, and type of journal.

RESULTS

There were 298 relevant studies. Between 2005 and 2010, there was an approximate fivefold increase in the number of FAI-related publications. Most of these studies came from the orthopaedic literature (197 articles or 66 %), while the remainder arose from other medical specialties. The majority of publications consisted of level 4 and 5 studies (248 articles). There were no level 1 studies identified.

CONCLUSION

Between 2005 and 2010, there has been a dramatic increase in FAI-related publications, but high-quality studies are still lacking.

LEVEL OF EVIDENCE

IV.

Relationship between femoroacetabular contact areas and hip position in the normal joint: an in vitro evaluation

PURPOSE

Different approaches have been proposed to diagnose femoroacetabular impingement (FAI) condition and hip instability. It is still debatable which test is the most effective to make a correct diagnosis. The true mechanics of the hip during particular physical examination manoeuvres is unknown.

METHODS

Eight fresh frozen hips were passively taken through 3 different commonly used positions for FAI diagnosis and hip instability: 90° Flexion-Adduction-Internal Rotation, Hyperextension-Adduction-External Rotation and Hyperextension-Neutral-External Rotation. Kinematics and anatomical data were acquired by an optoelectronic system. The contact areas between acetabulum and femoral head were analysed to determine whether these tests are able to localize regions of the hip that may give patients pain.

RESULTS

In the hip positions where the femur was in Hyperextension-External Rotation, the contact area was mainly concentrated in the posterosuperior area of the acetabulum, while during 90° Flexion-Adduction-Internal Rotation position, there was a wider distribution of contact, not specific to the anterolateral acetabulum.

CONCLUSIONS

The results confirm the ability of the Hyperextension-External Rotation tests to particularly analyse the posterior region of the acetabulum. Placing the hip in 90° of Flexion-Adduction-Internal Rotation allows for testing a wider zone of the acetabulum and is not specific to abutment of the femoral head-neck region against the anterolateral acetabulum.

Surgical indications for arthroscopic management of femoroacetabular impingement

PURPOSE

The clinical literature was systematically reviewed to determine the consistently reported indications for arthroscopic management of femoroacetabular impingement (FAI).

METHODS

Two databases (Medline and EMBASE) were screened for clinical studies involving the arthroscopic surgical management of FAI. A full-text review of eligible studies was conducted, and the references were searched. Articles published from 1980 until June 2011 were included, and the inclusion criteria were as follows: studies of human patients of all ages and genders with FAI, studies with a minimum of 6 months of patient follow-up, and studies reporting clinical outcome data. A quality assessment of the included articles was conducted.

RESULTS

We included 20 articles in this review, involving a total of 1,368 patients. We identified a lack of consensus on clinical and radiographic indications for the arthroscopic management of FAI. The indications varied from a positive impingement sign (45%) and symptoms or pain for more than 6 months (35%) to a series of positive special tests (25%). Commonly reported radiographic indicators for arthroscopic FAI management included the following: results from a computed tomography scan or magnetic resonance imaging (60%), cam or pincer lesions evident on anteroposterior and/or lateral radiographs (50%), loss of sphericity of the femoral neck (30%), acetabular retroversion (30%), magnetic resonance arthrography (25%), reduction in head-neck offset (25%), an alpha angle greater than 50° (25%), and coxa profunda (25%).

CONCLUSIONS

We found that there was great inconsistency among the indications for arthroscopic management of FAI. Clinical and radiographic indices remain largely unvalidated. This review highlights the need for more consistent reporting of surgical indications for the arthroscopic management of FAI. Future research should explore what combination of clinical and radiographic indications should be best used to determine arthroscopic FAI management.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II to IV studies.

Hip morphological characteristics and range of internal rotation in femoroacetabular impingement

BACKGROUND

Radiographic features specifically related to the occurrence of femoroacetabular impingement (FAI) appear to be highly prevalent in the asymptomatic population. It remains unclear, however, how these incidental findings should be interpreted clinically and which other variables might differentiate between true incidental findings and preclinical patients.

PURPOSE

To study the association between cam and overall hip morphological characteristics and range of motion in impingement patients, asymptomatic patients (healthy patients with radiographic features specific to FAI), and healthy controls.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Morphological parameters describing cam and overall hip anatomy were obtained from 30 patients (10 per subgroup) with use of 3-dimensional computational methods. In addition, the range of internal rotation in high flexion activities was evaluated, and its relation to hip morphological variables was analyzed in a multivariate regression model.

RESULTS

Size of the cam lesion and range of motion significantly differed between groups (P < .05). The range of internal rotation on impingement testing was found to average 27.9° in the healthy control group compared with 21.1° in the asymptomatic control group with radiographic features specific to FAI (P < .001) and 12.3° in the patient group (P < .001). Cam size, acetabular coverage, and femoral version appeared to be predictive variables for the range of internal rotation. Seventy-five percent of variance between patients could be attributed to the combined effect of these 3 variables (R = .86). The range of motion was decreased in cam patients and asymptomatic patients, and early femoroacetabular conflict was not restricted to the area of the cam lesion but involved the entire anterior femoral head-neck junction.

CONCLUSION

Decreased range of motion, as found in FAI, is not solely dependent on the size or even the occurrence of a cam lesion but should be interpreted by taking into account the overall hip anatomy, specifically femoral version and acetabular coverage. Decreased femoral anteversion and increased acetabular coverage add to the risk of early femoroacetabular collision during sports and activities of daily living and therefore appear to be additional predictive variables, besides the finding of a cam lesion, for the risk of clinical hip impingement development. In addition, the findings suggest that surgical osteochondroplasty to restore a normal range of motion may necessitate more excessive bone resection than what simply appears to be a bump on imaging.

Cam morphology in the human hip

A growing interest exists in the diagnosis and treatment of femoroacetabular impingement. Although cam morphology of the proximal femur may conceptually appear to be a relatively simple topographical aberrancy, it is actually positioned amid a complex developmental, kinematic, and biomechanical region of the human body. The authors introduce a new classification scheme and review the historical and anthropological considerations, biomechanics, and genetic factors involved in cam morphology.