Use of the S-hook for Pelvic Fixation in Rib-Based Treatment of Early-Onset Scoliosis: A Multicenter Study

Spine (Phila Pa 1976). 2015 Jun 1;40(11):816-22. doi: 10.1097/BRS.0000000000000443.


Study design: 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).

Summary of background data: 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.

Conclusion: 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.

Level of evidence: 3.

Publication types

  • Multicenter Study

MeSH terms

  • Child
  • Child, Preschool
  • Female
  • Follow-Up Studies
  • Humans
  • Ilium / diagnostic imaging
  • Ilium / surgery
  • Infant
  • Infections / etiology
  • Internal Fixators* / adverse effects
  • Male
  • Orthopedic Procedures / adverse effects
  • Orthopedic Procedures / instrumentation*
  • Orthopedic Procedures / methods
  • Prosthesis Design
  • Prosthesis Failure / etiology
  • Radiography
  • Retrospective Studies
  • Ribs / surgery
  • Scoliosis / diagnostic imaging
  • Scoliosis / surgery*
  • Spine / abnormalities
  • Spine / diagnostic imaging
  • Spine / surgery*