We have located links that may give you full text access.
Observed Length Increases of Magnetically Controlled Growing Rods are Lower Than Programmed.
Journal of Pediatric Orthopedics 2018 March
BACKGROUND: Magnetically controlled growing rods (MCGRs) are increasingly used in the treatment of early onset scoliosis (EOS). Few studies have reported whether desired lengthening can reliably be achieved, or if prior spine instrumentation and large tissue depths affect lengthening. In this clinical study of EOS patients, it was hypothesized that increases in rod length would equal programmed increases, patients with prior spine instrumentation would lengthen less than patients without prior surgery, and larger tissue depths would decrease lengthening success.
METHODS: A retrospective chart review was conducted on EOS patients with single and dual MCGRs placed between April 2014 to September 2015 and distracted at a single institution. Rod distraction was measured at each visit using ultrasound. Differences between programmed and actual distraction for each patient, and between groups with and without prior spine instrumentation, were determined by 2-tailed t tests. Regression and correlation were used to determine the relationship between tissue depth and length increases.
RESULTS: Thirty-one patients were included, 18 males, 13 females, age 8.1 (±2.5) years, with major curves measuring 60 (±14.6) degrees at time of MCGR insertion. In the 12 patients with prior instrumentation, time from initial growing rod placement to MCGR insertion was 23.1 (±10.6) months. The number of surgical procedures before MCGR insertion was 2.8 (±2.0). Total length increase relative to the programmed distraction was 86% (±21) (P<0.001). Length increases for patients with and without prior surgery were 87% (±23) and 86% (±19), respectively (P>0.9). Total lengthening was inversely proportional to tissue depth (r=0.38, P<0.01); the decrease in lengthening achieved was 2.1%/mm of tissue depth.
CONCLUSIONS: Increases in rod length were 14% lower than the programmed distraction. Prior instrumentation did not impact the amount of rod distraction. Greater distance between the rod and the skin surface negatively affected the magnitude of distraction.
METHODS: A retrospective chart review was conducted on EOS patients with single and dual MCGRs placed between April 2014 to September 2015 and distracted at a single institution. Rod distraction was measured at each visit using ultrasound. Differences between programmed and actual distraction for each patient, and between groups with and without prior spine instrumentation, were determined by 2-tailed t tests. Regression and correlation were used to determine the relationship between tissue depth and length increases.
RESULTS: Thirty-one patients were included, 18 males, 13 females, age 8.1 (±2.5) years, with major curves measuring 60 (±14.6) degrees at time of MCGR insertion. In the 12 patients with prior instrumentation, time from initial growing rod placement to MCGR insertion was 23.1 (±10.6) months. The number of surgical procedures before MCGR insertion was 2.8 (±2.0). Total length increase relative to the programmed distraction was 86% (±21) (P<0.001). Length increases for patients with and without prior surgery were 87% (±23) and 86% (±19), respectively (P>0.9). Total lengthening was inversely proportional to tissue depth (r=0.38, P<0.01); the decrease in lengthening achieved was 2.1%/mm of tissue depth.
CONCLUSIONS: Increases in rod length were 14% lower than the programmed distraction. Prior instrumentation did not impact the amount of rod distraction. Greater distance between the rod and the skin surface negatively affected the magnitude of distraction.
Full text links
Related Resources
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app