These are "MCGR" and Kiester's are "MAGEC" if I recall correctly. Maybe there are many such magnetic growth rods out there. Change one little thing and you get a patent on the same idea apparently. Not sure who got the first patent but it may be MCGR given they are trialing in the US and seem further ahead. This study was in the US I think but Kiester's rods are only being trialed in Europe for some reason last I knew.


Next Generation of Growth-Sparing Technique: Preliminary Clinical Results of a Magnetically Controlled Growing Rod (MCGR) in 14 Patients With Early Onset Scoliosis
Akbarnia, Behrooz A.; Cheung, Kenneth; Noordeen, Hilali; ElSebaie, Hazem; Yazici, Muharrem; Dannawi, Zaher; Kabirian, Nima
Spine., POST ACCEPTANCE, 10 October 2012
doi: 10.1097/BRS.0b013e3182773560
Purchase Access Published Ahead-of-Print
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PDF (735 KB)
Abstract
Abstract:
Study Design: Prospective non-randomized study.

Objective: To report the preliminary results of Magnetically Controlled Growing Rod (MCGR) technique in children with progressive early onset scoliosis (EOS).

Summary of Background Data: Growing rod (GR) technique is a viable alternative for treatment of EOS. High complication rate is attributed to frequent surgical lengthening. The safety and efficacy of MCGR was recently reported in a porcine model.

Methods: Multicenter study of clinical and radiographic data of patients underwent MCGR surgery and at least 3 distractions. Distractions were performed in clinic without anesthesia/analgesics. T1-T12 and T1-S1 heights and the distraction distance inside the actuator were measured after lengthening.

Results: 14 Patients (7 F, 7 M) with a mean age of 8y+10m (3y+6m to 12y+7m) had 14 index surgeries, single rod (SR) in 5 and dual rod (DR) in 9, with overall 68 distractions. Diagnoses were idiopathic (N=5), neuromuscular (N=4), congenital (N=2), syndromic (N=2) and NF (N=1). Mean follow-up (FU) was 10 months (5.8-18.2). Cobb angle changed from 60[degrees] to 34[degrees] after initial surgery and 31[degrees] at latest FU. During distraction period, T1-T12 height increased by 7.6 mm for SR (1.09 mm/month) and 12.12 mm for DR (1.97 mm/month). T1-S1 height gain was 9.1 mm for SR (1.27 mm/month) and 20.3 mm for DR (3.09 mm/month). Complications included superficial infection in 1 SR, prominent implant in 1 DR and minimal loss of initial distraction in 3 SR after index. Partial distraction loss observed following 14 of the 68 distractions (1 DR and 13 SR) but regained in subsequent distractions. There was no neurologic deficit or implant failure.

Conclusion: Preliminary results indicated MCGR was safe and provided adequate distraction similar to standard GR. DR achieved better initial curve correction and greater spinal height during distraction compared to SR. No major complications were observed during the FU.