title: Bony morphology of the hip in professional ballet dancers compared to athletes.
abstract: OBJECTIVE
  To compare hip bony morphology between ballet dancers and a sporting control group and to determine the relationship with hip pain.
  
  
  METHODS
  Thirty-three professional ballet dancers and 33 age- and sex-matched athletes completed questionnaires, including the Copenhagen Hip and Groin Outcome Score (HAGOS), and underwent clinical testing and 3.0-T magnetic resonance imaging to measure acetabular coverage with lateral centre edge angles, femoral head-neck junction concavity with alpha angles at anterior and superior positions, femoral neck-shaft angles, and acetabular version angles.
  
  
  RESULTS
  Bony morphological measures fell within normal ranges. Dancers had higher neck-shaft angles (dancers 134.6 ± 4.6°/athletes130.8 ± 4.7°, p = 0.002), lower acetabular version angles (13.5 ± 4.7°/17.1 ± 4.7°, p = 0.003), lower superior alpha angles (38.9 ± 6.9°/46.7 ± 10.6°, p < 0.001), similar anterior alpha angles (43.6 ± 8.1/46 ± 7°, p = 0.2), and similar lateral centre edge angles (28.8 ± 4.6°/30.8 ± 4.5°, p = 0.07) compared to athletes. Abnormal morphology was detected in dancers: 3% acetabular dysplasia (athletes 0), 15% borderline dysplasia (6%), 24% cam morphology (33%), 24% coxa valga (6%), and 21% acetabular retroversion (18%). The HAGOS pain scores correlated moderately with acetabular version (r = -0.43, p = 0.02) in dancers, with no other correlation between pain and morphological parameters in either group.
  
  
  CONCLUSIONS
  Professional ballet dancers have hip bony morphology that differentiates them from athletes. Hip pain correlated poorly with bony morphology.
  
  
  CONCLUSIONS
  • Ballet dancers have hip bony morphology that may allow extreme hip motion. • Morphological parameter means fell within normal reference intervals in dancers. • Bony morphology correlates poorly with hip pain. • The risk of hip injury due to abnormal morphology requires prospective studies.
authors.affiliation: The Australian Ballet, 2 Kavanagh St Southbank, Victoria, 3006, Australia. suem@australianballet.com.au.|School of Allied Health, La Trobe University, Bundoora, Victoria, 3086, Australia. suem@australianballet.com.au.
authors.forename: Susan
authors.initials: S
authors.lastname: Mayes
authors.affiliation: Department of Physiotherapy School of Primary Health Care Faculty of Medicine, Nursing and Health Sciences Monash University - Peninsula Campus, PO Box 527, Frankston, Victoria, 3199, Australia.
authors.forename: April-Rose
authors.initials: AR
authors.lastname: Ferris
authors.affiliation: MIA East Melbourne Radiology, Level 1, 141 Grey Street, East Melbourne, VIC, 3002, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Smith
authors.affiliation: School of Exercise and Nutrition Sciences, Deakin University, 221 Burwood Highway, Burwood, Victoria, 3125, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Garnham
authors.affiliation: School of Allied Health, La Trobe University, Bundoora, Victoria, 3086, Australia.
authors.forename: Jill
authors.initials: J
authors.lastname: Cook
mesh_terms: D000293:Adolescent; D000328:Adult; D018771:Arthralgia / Q000175:diagnosis* / Q000209:etiology; D056352:Athletes; D003615:Dancing; D003937:Diagnosis, Differential; D005260:Female; D057925:Femoracetabular Impingement / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009784:Occupational Diseases / Q000150:complications / Q000175:diagnosis*; D016273:Occupational Exposure / Q000009:adverse effects; D010384:Pelvic Bones / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D055815:Young Adult
keywords: Acetabular dysplasia; Acetabular version; Femoroacetabular impingement; Hip pain; Neck-shaft angle