title: Suprascapular notch variations: a 3DCT study.
abstract: BACKGROUND
  Although cadaveric studies have revealed suprascapular notch shape variations, few have investigated the association between suprascapular notch variation and age or gender. The purpose of this study was to investigate suprascapular notch shape variations by use of three-dimensional computed tomography (3DCT) and to determine if there was any association with age or gender.
  
  
  METHODS
  Three-dimensional CT images of 762 shoulders of 762 patients were analyzed in this study. Participants comprised 404 men and 358 women, with an average age of 58.2 ± 19.1 years. Suprascapular notch shape variations were classified into six types on the basis of Rengachary's classification.
  
  
  RESULTS
  Of the total study population, 11.4% were classified as type I, 23.5% as type II, 30.1% as type III, 14.8% as type IV, 15.9% as type V, and 4.3% as type VI. Average age was 56.5 ± 20.5 years for type I, 57.0 ± 19.5 years for type II, 55.5 ± 20.0 years for type III, 56.4 ± 18.5 years for type IV, 65.5 ± 14.4 years for type V, and 68.0 ± 13.4 years for type VI. Statistically significant age differences were found between types I-IV and V, between types I-IV and VI, and between the non-ossification group (types I-IV) and the ossification group (types V and VI). Male-to-female ratio among each type, and between the non-ossification group and the ossification group, were not statistically significantly different.
  
  
  CONCLUSIONS
  Our results suggest that transverse scapular ligament ossification is associated with aging whereas individual variation explains differences among types I, II, III, and IV. Three-dimensional CT provides useful information for arthroscopic resection of the transverse scapular ligament, when the wide variety of suprascapular notch shape variations is considered.
  
  
  METHODS
  Level IV.
authors.affiliation: Department of Orthopaedic Surgery, Nara Medical University, 840 Shijoutyou, Kashihara, Nara, 634-5822, Japan, kaz_inoue12@ybb.ne.jp.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Inoue
authors.forename: Naoki
authors.initials: N
authors.lastname: Suenaga
authors.forename: Naomi
authors.initials: N
authors.lastname: Oizumi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Goro
authors.initials: G
authors.lastname: Sakurai
authors.forename: Naoki
authors.initials: N
authors.lastname: Miyoshi
authors.forename: Noboru
authors.initials: N
authors.lastname: Taniguchi
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000368:Aged; D002102:Cadaver; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D012540:Scapula / Q000000981:diagnostic imaging*; D012785:Shoulder Joint / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*