title: Technique of cervicothoracic junction pedicle subtraction osteotomy for cervical sagittal imbalance: report of 11 cases.
abstract: OBJECTIVE
  Sagittal imbalance of the cervicothoracic spine often causes severe pain and loss of horizontal gaze. Historically, the Smith-Peterson osteotomy has been used to restore sagittal balance. Cervicothoracic junction pedicle subtraction osteotomy (PSO) offers more controlled closure and greater biomechanical stability but has been infrequently reported in the literature. This study details the cervicothoracic PSO technique in 11 cases and correlates clinical kyphosis (chin-brow to vertical angle [CBVA]) with radiographic measurements.
  
  
  METHODS
  Between February 2008 and September 2010, 11 patients (mean age 70 years) underwent a modified PSO (10 at C-7, 1 at T-1) for treatment of sagittal imbalance. Preoperative and postoperative sagittal plane radiographic measurements were made. The CBVA was measured on clinical photographs. Operative technique and perioperative correction were reported for all 11 patients and long-term follow-up data was reported for 9 patients, in whom the mean duration of follow-up was 23 months. Outcome measures used for these 9 patients were the Neck Disability Index, the 36-Item Short Form Health Survey (SF-36), and a visual analog scale for neck pain.
  
  
  RESULTS
  The mean values for estimated blood loss, surgical time, and hospital stay in the 11 patients were 1100 ml, 4.3 hours, and 9.9 days, respectively. The mean preoperative and immediate postoperative values (± SD) for cervical sagittal imbalance were 7.9 ± 1.4 cm and 3.4 ± 1.7 cm. The mean overall correction was 4.5 ± 1.5 cm (42.8%), the mean PSO correction 19.0°, and the mean CBVA correction 36.7°. There was essentially no correlation between preoperative C2-T1 radiographic kyphosis and preoperative CBVA (R(2) = 0.0165). There was a moderate correlation with PSO correction angle and postoperative CBVA (R(2) = 0.38). There was a significant decrease in both the Neck Disability Index (51.1 to 38.6, p = 0.03) and visual analog scale scores for neck pain (8.1 to 3.9, p = 0.0021). The SF-36 physical component summary scores increased by 18.4% (30.2 to 35.8) with no neurological complications.
  
  
  CONCLUSIONS
  The cervicothoracic junction PSO is a safe and effective procedure for the management of cervicothoracic kyphotic deformity. It results in excellent correction of cervical kyphosis and CBVA with a controlled closure and improvement in health-related quality-of-life measures even at early time points.
authors.affiliation: Department of Orthopaedic Surgery, University of California, San Francisco, California 94143, USA.
authors.forename: Vedat
authors.initials: V
authors.lastname: Deviren
authors.forename: Justin K
authors.initials: JK
authors.lastname: Scheer
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D011859:Radiography; D012189:Retrospective Studies; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome