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

ABSTRACT

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.

KEYWORDS:

• Hip
• femoroacetabular impingement
• breaking athletes
• break dance
• Bboying
• Bboy dancers
• hip-hop dance
• cam morphology
• pincer morphology

Institutional Review Board Statement

The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the local institutional ethics board.

Informed consent statement

Professional breakers were included after written informed consent. The local institutional ethics board waived patient consent of the hobby athlete group due to the retrospective study character.

Data availability statement

The data presented in this study are available on request from the corresponding author. The data are not publicly available due to local institutional ethics board regulations.

Disclosure statement

The authors report there are no competing interests to declare.

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00913847.2023.2256210.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.