Finite Element Comparison of the Spring Distraction System and the Traditional Growing Rod for the treatment of Early Onset Scoliosis

Abstract Study design A cross-sectional retrospective Level 3 study. Objective To study the serum levels of Titanium and Aluminium ions in patients operated using the magnetically controlled growing rod (MCGR) system. Summary of background data 14 consecutive patients of early onset scoliosis with varying etiology managed with MCGR system with a minimum follow-up of 24 months were selected for the study. The group consisted of two boys (14.3%) and 12 girls (85.7%). The average age of the patients at the time of surgery was 10.4 years (5–15 years). The average period of follow-up was 43.7 months (28–79 months). After informed consent of the subjects and their caretakers, serum levels of titanium and aluminium were measured. These levels were then assessed with regards to the number of screws used, number of distractions and complications. Methods The concentration of titanium and aluminium ions in the serum was measured using high resolution inductively coupled plasma mass spectrometry. Results For the sake of ease of assessment, patients were divided into three etiology-based groups—idiopathic (n = 6), neuromuscular (n = 2) and syndromic (n = 6). The mean serum titanium level was 15.9 μg/L (5.1–28.2 μg/L) while that of aluminium was 0.1 μmol/L (0.1–0.2 μmol/L). Of the 14 patients, 2 (14.2%) patients had mechanical failure (actuator pin dysfunction), 3 (21.4%) had rod breakage requiring revision surgery and one patient (7.1%) had surgical site infection managed with appropriate antibiotics. Patients undergoing revision for rod breakage did not show any metallosis of the tissues during surgery. Conclusion Analysis of patients with scoliosis operated using the magnetic growing rod system concludes that it is accompanied by presence of titanium in the blood but whether clinically significant or not needs to be ascertained by comparison of preoperative and postoperative blood concentrations of the titanium ions in individual subjects. The aluminium ion concentration remains within normal limits. Though implant malfunction may raise the titanium levels in the blood, its clinical significance needs to be determined. The aluminium levels are not affected irrespective to the presence or absence of complications. The long-term effects of raised titanium levels in the blood also warrant further prospective studies designed for precise and deeper analyses.

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Retrieval and clinical analysis of distraction-based dual growing rod constructs for early-onset scoliosis

The Spine Journal ◽

10.1016/j.spinee.2017.04.020 ◽

2017 ◽

Vol 17 (10) ◽

pp. 1506-1518 ◽

Cited By ~ 8

Author(s):

Genevieve Hill ◽

Srinidhi Nagaraja ◽

Behrooz A. Akbarnia ◽

Jeff Pawelek ◽

Paul Sponseller ◽

...

Keyword(s):

Early Onset ◽

Clinical Analysis ◽

Early Onset Scoliosis ◽

Growing Rod

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Evaluation of changes in shoulder balance and prediction of final shoulder imbalance during growing-rod treatment for early-onset scoliosis

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04221-9 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Ziyang Liu ◽

Tie Liu ◽

Yong Hai ◽

Lingyun Wu ◽

Junrui Jonathan Hai ◽

...

Keyword(s):

Early Onset ◽

Demographic Data ◽

Potential Effect ◽

Early Onset Scoliosis ◽

Shoulder Balance ◽

Related Factors ◽

Growing Rod ◽

Shoulder Imbalance ◽

Entire Treatment

Abstract Background Obtaining and maintaining final shoulder balance after the entire treatment course is essential for early-onset scoliosis (EOS) patients. The relatively small number of growing-rod (GR) graduates who complete final fusion has resulted in an overall paucity of research on the GR treatment of EOS and a lack of research on the shoulder balance of EOS patients during GR treatment. Methods Twenty-four consecutive patients who underwent GR treatment until final fusion were included. Radiographic shoulder balance parameters, including the radiographic shoulder height (RSH), clavicle angle (CA), and T1 tilt angle (T1T), before and after each step of the entire treatment were measured. Shoulder balance changes from GR implantation to the last follow-up after final fusion were depicted and analysed. Demographic data, surgical-related factors, and radiographic parameters were analysed to identify risk factors for final shoulder imbalance. The shoulder balance of patients at different time points was further analysed to explore the potential effect of the series of GR treatment steps on shoulder balance. Results The RSH showed substantial improvement after GR implantation (P = 0.036), during the follow-up period after final fusion (P = 0.021) and throughout the entire treatment (P = 0.011). The trend of change in the CA was similar to that of the RSH, and the T1T improved immediately after GR implantation (P = 0.037). Further analysis indicated that patients with shoulder imbalance before final fusion showed significantly improved shoulder balance after fusion (P = 0.045), and their RSH values at early postfusion and the final follow-up did not show statistically significant differences from those in the prefusion shoulder balance group (P > 0.05). Early postfusion shoulder imbalance (odds ratio (OR): 19.500; 95% confidence interval (CI) = 1.777–213.949; P = 0.015) was identified as an independent risk factor for final shoulder imbalance. Conclusions Shoulder balance could be improved by GR implantation but often changes during the multistep lengthening process, and the final result is relatively unpredictable. Final fusion could further adjust the prefusion shoulder imbalance. Focusing on the prefusion shoulder balance of GR graduates and providing patients with early shoulder balance after fusion might be necessary.

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Improved growing rod for early onset scoliosis

2008 IEEE Biomedical Circuits and Systems Conference ◽

10.1109/biocas.2008.4696957 ◽

2008 ◽

Author(s):

Scott Decker ◽

Gabriel Kim ◽

Mark Kim ◽

Benjamin Lee

Keyword(s):

Early Onset ◽

Early Onset Scoliosis ◽

Growing Rod

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Complications of Growing-Rod Treatment for Early-Onset Scoliosis

The Journal of Bone and Joint Surgery (American) ◽

10.2106/jbjs.i.01471 ◽

2010 ◽

Vol 92 (15) ◽

pp. 2533-2543 ◽

Cited By ~ 312

Author(s):

Shay Bess ◽

Behrooz A Akbarnia ◽

George H Thompson ◽

Paul D Sponseller ◽

Suken A Shah ◽

...

Keyword(s):

Early Onset ◽

Early Onset Scoliosis ◽

Growing Rod

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Mid-term results of a modified self-growing rod technique for the treatment of early-onset scoliosis

The Bone & Joint Journal ◽

10.1302/0301-620x.102b11.bjj-2020-0412.r3 ◽

2020 ◽

Vol 102-B (11) ◽

pp. 1560-1566

Author(s):

Hossein Mehdian ◽

Sleiman Haddad ◽

Dritan Pasku ◽

Luigi Aurelio Nasto

Keyword(s):

Cerebral Palsy ◽

Cobb Angle ◽

Early Onset ◽

Early Onset Scoliosis ◽

Growth Spurt ◽

Spinal Growth ◽

Growing Rod ◽

The Mean ◽

Mid Term Results

Aims To report the mid-term results of a modified self-growing rod (SGR) technique for the treatment of idiopathic and neuromuscular early-onset scoliosis (EOS). Methods We carried out a retrospective analysis of 16 consecutive patients with EOS treated with an SGR construct at a single hospital between September 2008 and December 2014. General demographics and deformity variables (i.e. major Cobb angle, T1 to T12 length, T1 to S1 length, pelvic obliquity, shoulder obliquity, and C7 plumb line) were recorded preoperatively, and postoperatively at yearly follow-up. Complications and revision procedures were also recorded. Only patients with a minimum follow-up of five years after surgery were included. Results A total of 16 patients were included. Six patients had an idiopathic EOS while ten patients had a neuromuscular or syndromic EOS (seven spinal muscular atrophy (SMA) and three with cerebral palsy or a syndrome). Their mean ages at surgery were 7.1 years (SD 2.2) and 13.3 years (SD 2.6) respectively at final follow-up. The mean preoperative Cobb angle of the major curve was 66.1° (SD 8.5°) and had improved to 25.5° (SD 9.9°) at final follow-up. The T1 to S1 length increased from 289.7 mm (SD 24.9) before surgery to 330.6 mm (SD 30.4) immediately after surgery. The mean T1 to S1 and T1 to T12 growth after surgery were 64.1 mm (SD 19.9) and 47.4 mm (SD 18.8), respectively, thus accounting for a mean T1 to S1 and T1 to T12 spinal growth after surgery of 10.5 mm/year (SD 3.7) and 7.8 mm/year (SD 3.3), respectively. A total of six patients (five idiopathic EOS, one cerebral palsy EOS) had broken rods during their growth spurt but were uneventfully revised with a fusion procedure. No other complications were noted. Conclusion Our data show that SGR is a safe and effective technique for the treatment of EOS in nonambulatory hypotonic patients with a neuromuscular condition. Significant spinal growth can be expected after surgery and is comparable to other published techniques for EOS. While satisfactory correction of the deformity can be achieved and maintained with this technique, a high rate of rod breakage was seen in patients with an idiopathic or cerebral palsy EOS. Cite this article: Bone Joint J 2020;102-B(11):1560–1566.

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