Mechanical analysis and treatment of Harrington-rods broken after initial operation for scoliosis.
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.
Weng
X
X
Department of Orthopedics, PUMC Hospital, CAMS & PUMC, Beijing 100730.
Zhang
J
J
Qiu
G
G
Jin
J
J
Lin
J
J
D000293:Adolescent; D000328:Adult; D002648:Child; D020878:Device Removal; D004868:Equipment Failure; D005260:Female; D006801:Humans; D016268:Internal Fixators; D008297:Male; D012600:Scoliosis / Q000601:surgery*