Bony Morphology of Femoroacetabular Impingement in Young Female Dancers and Single-Sport Athletes

Increased asphericity of the femoral head-neck junction in professional breakers compared to hobby athletes - a retrospective case-control study

OBJECTIVE

Breaking has gained public attention as a form of sports activity. The associated intense movements of the hip joints are possibly linked to the development of femoroacetabular impingement (FAI). Therefore, this study aimed to assess clinical and radiographic FAI measures in professional breakers compared to hobby athletes.

METHODS

The study cohort consisted of professional breakers with persisting hip pain who were 1:1 matched to a cohort of FAI patients without professional sports careers from our outpatient clinic. The primary endpoint assessed on standardized plain radiographs was the alpha angle (AA). Further measures were the acetabular index (AI), lateral center-edge angle (LCEA), crossover sign, ischial spine sign, and femoral head extrusion index (FHEI). The modified Harris Hip Score (mHHS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were used to obtain patient-reported measures.

RESULTS

We recruited ten professional breakers and matched them to ten hobby athletes. The median AA was significantly higher in the breakers compared with the hobby athletes (73° [IQR 66.5°, 84.2°]) vs. 61.8° [IQR 59.5°, 64.8°], p = 0.0004). There was a significant reduction in weekly training hours in breakers after diagnosis (13.0 hours [interquartile range [IQR] 9.5, 32.4] to 1.5 hours [IQR 0, 4.8], p = 0.0039). There were no inter-group differences regarding mHHS, WOMAC, and additional radiographic measurements.

CONCLUSION

Breakers have higher AA in cam-type FAI compared to nonprofessional athletes. The corresponding hip pain significantly reduced training hours and caused the end of their breaking career. The potentially high prevalence of FAI in breakers and the corresponding consequences need to be considered early when athletes present with hip pain.

Little or No Differences in Hip Morphology Between Professional Dancers and Controls: A Systematic Review

OBJECTIVE

To systematically evaluate and synthesize the literature on bony hip morphology of professional dancers, as measured by 2D or 3D imaging techniques.

DATA SOURCES

A literature search was performed on November 20, 2020, using MEDLINE, Embase, and Cochrane. Clinical studies were eligible if they reported on hip morphology of professional dancers. Two independent reviewers screened titles, abstracts, and full-texts to determine eligibility; performed data extraction; and assessed the quality of eligible studies according to the Joanna Briggs Institute (JBI) checklist. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

MAIN RESULTS

The search returned 1384 records; 449 were duplicates, 923 were excluded after title/abstract/full-text screening, and 12 were eligible, reporting on 447 individuals (352 professional dancers and 95 controls). The JBI checklist indicated that 11 studies scored ≥4 points. For professional dancers, lateral center edge angle was 22.4 to 30.8 degrees, acetabular version was 6.7 to 13.5 degrees, neck-shaft angle was 132.5 to 139.5 degrees, and femoral version was 4.7 to 14.4 degrees. Statistically significant differences between dancers and controls were found in some of the studies for acetabular version, neck-shaft angle, and femoral version, although only femoral version showed clinically relevant differences.

CONCLUSIONS

The bony hip morphology of professional dancers is similar to that of other athletes and age-matched controls, which is in contrast to the authors' clinical experience. We presume that the abnormal morphology we have seen at the clinic is only present in symptomatic dancers who require total hip arthroplasty (THA) and is not a general characteristic of all dancers. Further studies should compare the hip morphology of dancers undergoing THA with matched nondancers.

Does the Type of Sport Influence Morphology of the Hip? A Systematic Review

BACKGROUND

Femoroacetabular impingement (FAI) has been extensively investigated and is strongly associated with athletic participation.

PURPOSE

To assess (1) the prevalence of cam-type FAI across various sports; (2) whether kinematic variation among sports influences hip morphology; and (3) whether performance level, duration, and frequency of participation or other factors influence hip morphology in a sporting population.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic search of Embase, PubMed, and the Cochrane Library was undertaken following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Prospective and retrospective case series, case reports, and review articles published after 1999 were screened, and those that met the inclusion criteria decided a priori were included for analysis.

RESULTS

The literature search identified 58 relevant articles involving 5683 participants. A total of 49 articles described a higher prevalence of FAI across various "hip-heavy" sports, including soccer, basketball, baseball, ice hockey, skiing, golf, and ballet. In studies including nonathlete controls, a greater prevalence of FAI was reported in 66.7% of studies (n = 8/12). The highest alpha angle was identified at the 1-o'clock position (n = 9/9) in football, skiing, golf, ice hockey, and basketball. The maximum alpha angle was located in a more lateral position in goalkeepers versus positional players in ice hockey (1 vs 1:45 o'clock). A positive correlation was also identified between the alpha angle and both age and activity level (n = 5/8 and n = 2/3, respectively) and between prevalence of FAI and both age and activity level (n = 2/2 and n = 4/5).

CONCLUSION

Hip-heavy sports show an increased prevalence of FAI, with specific sporting activities influencing hip morphology. There is some evidence to suggest that a longer duration and higher level of training also result in an increased prevalence of FAI.

REGISTRATION

CRD4202018001 (PROSPERO).

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

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

Characteristics of femoroacetabular impingement morphology and relation with skeletal maturity among asymptomatic adolescents

The aim of this study was to analyze presence of the morphological characteristics and prevalence of FAI in asymptomatic adolescents and assess the relation of skeletal maturation with development of FAI morphology. Abdominopelvic computed tomography (CT) of 265 adolescents (9-19 years old) who were admitted to the emergency department between 2011 and 2016 were evaluated retrospectively. Radial reformatted CT images from the femoral neck were created using the multiplanar reconstruction (MPR) method. The femoral neck was divided into 12 segments and alpha angle (AA), femoral head-neck ratio (FHNR) and center-edge angle (CEA) were measured from each segment. Additionally, images were evaluated for the physiological status (open or closed) of the triradiate- cartilage and proximal femoral epiphyses. 204 hips from 102 patients (32 females, 70 males) were retrospectively reviewed. There were 27 (26.5%) patients with cam-type morphology and 18 (17.6%) patients with pincer-type morphologies. No statistically significant difference was detected between the prevalences of cam and pincer morphologies between the two genders. Cam deformity was most frequently seen in anterosuperior segment. All of the patients (100%) with pincer-type morphology and 88% of the patients with cam-type morphology had closed triradiate cartilage, 89% of the patients with cam morphology and 83% with pincer morphology had open proximal femoral physis. Our results showed that prevalence of cam and pincer-type morphology in asymptomatic adolescents is similar to asymptomatic adults. Our findings also indicate that cam- and pincer-type FAI morphologies likely develop during late adolescence after closure of triradiate cartilage and before closure of proximal femoral physis. Level of Evidence - 3

Reported Prevalence of Radiographic Cam Deformity Based on Sport: A Systematic Review of the Current Literature

Background

Repetitive loading and shear stress across the proximal femur account for the high prevalence of cam deformity in athletes.

Purpose

To systematically review the literature to identify the reported number, age, mean alpha angle measurements, and differences between male and female athletes with radiographic cam deformity based on sport.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was conducted of studies in the literature between January 1990 and March 2018 that reported on athletes with radiographic cam deformity based on sport. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed, and PubMed, Biosis Previews, SPORTDiscus, PEDro, and EMBASE databases were used. Inclusion criteria included studies documenting radiographic cam deformity based on alpha angle measurements categorized according to the athlete's primary sport and according to sex. Exclusion criteria were (1) studies not documenting primary sport, (2) studies not reporting total number of athletes with radiographic cam deformity, and (3) studies not separating cam deformity based on sex or using alpha angle measurements. Statistical analysis was used to compare mean reported age and alpha angle measurements between males and females.

Results

A total of 28 studies consisting of 1160 male and 53 female athletes with radiographic cam deformity were identified. Cam lesions were most commonly reported in soccer athletes among both males and females, followed by hockey and American football. Male athletes had significantly higher mean alpha angle measurements (59.9° ± 5.5°) compared with female athletes (48.3° ± 6.9°) (P = .001). No significant difference in age was appreciated between males (21.1 ± 4.0 years) and females (21.7 ± 3.0 years) (P = .62).

Conclusion

Radiographic cam deformity is most commonly reported in athletes participating in soccer and hockey. Males possessed significantly greater mean alpha angle measurements compared with females, whereas no significant difference in mean age at the time of diagnosis was appreciated between sexes.