title: Use of the S-hook for Pelvic Fixation in Rib-Based Treatment of Early-Onset Scoliosis: A Multicenter Study.
abstract: METHODS
  Retrospective review.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate how several preoperative variables affect the outcome using the rib-to-pelvis S-hook constructs of a rib-based distraction implant (Vertical Expandable Prosthetic Titanium Rib).
  
  
  BACKGROUND
  Rib-to-pelvis fixation with S-hooks is one of the options for distal anchoring of rib-based distraction growing rod construct to control early-onset spinal deformity. Since the initial report, the indications of pelvic fixation with S-hooks have been extended and modified.
  
  
  METHODS
  This is an institutional review board-approved retrospective study of patients who underwent rib-based growing rod system surgery-rib-to-pelvis construct with Dunn-McCarthy S-hook. Data evaluation included history, physical examination, preoperative and postoperative radiographs, surgical variables, and complications.
  
  
  RESULTS
  Sixty-five patients were evaluated; 38 were male and 27 were female. Mean age at initial procedure was 71 months. The mean follow-up was 46 months. There was a statistically significant improvement of the immediate postoperative Cobb angle and the last follow-up Cobb angle (P < 0.0001). Fifty percent of the patients (32/65) had S-hook-related complications. The most common complication was sliding of the S-hook out of the iliac crest, followed by infection, neuropathic pain, distal migration of more than 2 cm, fracture of the hook, and bursitis. The complications were related to the preoperative ambulatory status, the use of end-to-end rod connectors, surgical time, and not positioning the hook over the central one-third of the iliac crest at the initial implantation.
  
  
  CONCLUSIONS
  The use of the S-hook as a pelvic attachment of the rib-based system is indicated in nonambulatory patients with progressive, early-onset scoliosis curve with a lack of adequate anchor at the lumbar spine. Several technical factors should be considered to reduce the complication rate.
  
  
  METHODS
  3.
authors.affiliation: *Pediatric Orthopedic Department, Hospital de la Concepción, San German, Puerto Rico †Mayagüez Medical Center, Mayagüez, Puerto Rico ‡Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, UT §Primary Children's Hospital, Salt Lake City, UT ¶Division of Pediatric Orthopaedics, Pediatric Spine and Scoliosis Service, Morgan Stanley Children's Hospital of New York-Presbyterian, Columbia University Medical Center, New York, NY ‖Alvin Crawford Spine Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH **Shriners Hospital for Children, Portland, OR ††Shriners Hospitals for Children-Philadelphia, Philadelphia, PA ‡‡Department of Biometry, University of Puerto Rico, Mayaguez §§Department of Surgery (Orthopaedics), Department of Surgery (Neurosurgery), and School of Biomedical Engineering, Dalhousie University; and ¶¶IWK Health Centre, Halifax, Nova Scotia, Canada.
authors.forename: Norman
authors.initials: N
authors.lastname: Ramirez
authors.forename: John M
authors.initials: JM
authors.lastname: Flynn
authors.forename: John T
authors.initials: JT
authors.lastname: Smith
authors.forename: Michael
authors.initials: M
authors.lastname: Vitale
authors.forename: Peter F
authors.initials: PF
authors.lastname: Sturm
authors.forename: Charles
authors.initials: C
authors.lastname: DʼAmato
authors.forename: Amer
authors.initials: A
authors.lastname: Samdani
authors.forename: Raul
authors.initials: R
authors.lastname: Machiavelli
authors.forename: Ron
authors.initials: R
authors.lastname: El-Hawary
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007085:Ilium / Q000000981:diagnostic imaging / Q000601:surgery; D007223:Infant; D007239:Infections / Q000209:etiology; D016268:Internal Fixators / Q000009:adverse effects; D008297:Male; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology; D011859:Radiography; D012189:Retrospective Studies; D012272:Ribs / Q000601:surgery; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013131:Spine / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery*