Mechanical analysis and treatment of Harrington-rods broken after initial operation for scoliosis

Chin Med Sci J. 1997 Dec;12(4):232-5.

Abstract

Twenty-two cases of scoliosis with Harrington-rods broken after operation were treated by rod-sleeve method. The results of follow-up from 1 year and 3 months to 9 years and 3 months showed that all of the patients, but one patient occurred Harrington-rod rebroken and one's fixation being removed because of back pain in 6 months and 5 years and 11 months after rod-sleeve procedure, respectively, had no complaints. The author also found that the rod underwent a decrease in cross-sectional area of approximately 43.7% at the ratchet-shaft junction in experimental study on Harrington-rods, and stress unfairly distribution, stress concentration and cyclic loading producing fatigue in metals were proved to be the main cause of broken by mechanical analysis of Harrington-rod loaded in the body. In concluson, the rod-sleeve procedure was the effective method to keep from Harrington-rods broken.

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Device Removal
  • Equipment Failure
  • Female
  • Humans
  • Internal Fixators*
  • Male
  • Scoliosis / surgery*