title: Is neck tilt and shoulder imbalance the same phenomenon? A prospective analysis of 89 adolescent idiopathic scoliosis patients (Lenke type 1 and 2).
abstract: OBJECTIVE
  To introduce a new clinical neck tilt grading and to investigate clinically and radiologically whether neck tilt and shoulder imbalance is the same phenomenon in AIS patients.
  
  
  METHODS
  89 AIS Lenke 1 and 2 cases were assessed prospectively using the new clinical neck tilt grading. Shoulder imbalance and neck tilt were correlated with coracoid height difference (CHD), clavicle\rib intersection distance (CRID), clavicle angle (CA), radiographic shoulder height (RSH), T1 tilt and cervical axis.
  
  
  RESULTS
  Mean age was 17.2 ± 3.8 years old. 66.3 % were Lenke type 1 and 33.7 % were type 2 curves. Strong intraobserver (0.79) and interobserver (0.75) agreement of the clinical neck tilt grading was noted. No significant correlation was observed between clinical neck tilt and shoulder imbalance (0.936). 56.3 % of grade 3 neck tilt, 50.0 % grade 2 neck tilt patients had grade 0 shoulder imbalance. In patients with grade 2 shoulder imbalance, 42.9 % had grade 0, 35.7 % grade 1, 14.3 % grade 2 and only 7.1 % had grade 3 neck tilt. CHD, CRID, CA and RSH correlated with shoulder imbalance. T1 tilt and cervical axis measurements correlated with neck tilt.
  
  
  CONCLUSIONS
  In conclusion, neck tilt is distinct from shoulder imbalance. Clinical neck tilt has poor correlation with clinical shoulder imbalance. Clinical neck tilt grading correlated with cervical axis and T1 tilt whereas clinical shoulder grading correlated with CHD, RSH CRID and CA.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, 50603, Lembah Pantai, Kuala Lumpur, Malaysia. munkeong42@hotmail.com.
authors.forename: Mun Keong
authors.initials: MK
authors.lastname: Kwan
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, 50603, Lembah Pantai, Kuala Lumpur, Malaysia. wka80@hotmail.com.
authors.forename: Kai Ann
authors.initials: KA
authors.lastname: Wong
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, 50603, Lembah Pantai, Kuala Lumpur, Malaysia. kenetto@hotmail.com.
authors.forename: Chee Kean
authors.initials: CK
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, 50603, Lembah Pantai, Kuala Lumpur, Malaysia. chrnat01@yahoo.com.
authors.forename: Chris Yin Wei
authors.initials: CY
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D002968:Clavicle / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D009333:Neck / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011446:Prospective Studies; D011859:Radiography; D012272:Ribs / Q000000981:diagnostic imaging / Q000503:physiopathology; D012600:Scoliosis / Q000145:classification / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D012782:Shoulder / Q000000981:diagnostic imaging* / Q000503:physiopathology*
keywords: Adolescent idiopathic scoliosis; Lenke 1; Lenke 2; Neck tilt; Shoulder imbalance