Magnetically controlled growing instrumentation for early onset scoliosis: Caution needed when interpreting the literature

Table 1 Summary of patient and surgery characteristics for identified patients undergoing magnetically controlled growing rods instrumentation, n (%)

Items
Curve etiology
Idiopathic	89 (32.8)
Congenital	43 (15.9)
Syndromic	68 (25.1)
Neuromuscular	63 (23.2)
Neurofibromatosis	8 (2.9)
Type of surgery
Primary	195 (74.7)
Conversion	66 (25.3)
Unspecified	10
Type of instrumentation
Single rod	64 (23.6)
Dual rod	207 (76.4)

Table 2 Summary of hardware related complications following magnetically controlled growing rods instrumentation for early onset scoliosis

	Complication rate	Without keeper plate	With keeper plate
Overall complication rate/study	35.6% (n = 115)	80.61% (n = 38)	35.65% (n = 77)
Major complications	n = 95	n = 32	n = 63
Cumulative Complications
Distraction failure	14.0% (n = 38)	40.8% (n = 20)	8.1% (n = 18)
Implant failure	8.86% (n = 24)	18.36% (n = 9)	6.76% (n = 15)
Screw pull-out	8.12% (n = 22)	4.1% (n = 2)	9.0% (n = 20)
Infection	2.2% (n = 6)	2.04% (n = 1)	2.25% (n = 5)
Prominent hardware	2.58% (n = 7)	14.28% (n = 7)	0% (n = 0)
Proximal junctional kyphosis	2.58% (n = 7)	0% (n = 0)	3.15% (n = 7)
Wound dehiscence	0.74% (n = 2)	0% (n = 0)	0.9% (n = 2)

Table 3 Summary of articles included for analysis

First author	Yr	Keeper plate?	# Of patients	Primary surgeries	Revisions	% Male	Age at surgery (yr)	Curve magnitude
Hickey[8]	2014	Y	8	4	4	75%	4.5	59.25
Akbarnia[6]	2014	N	12	12	0	42%	6.8	59
Lebon[4]	2017	Y	30	25	5	53%	9.1	66
Akbarnia[2]	2013	N	14	14	0	50%	8.83	60
Thompson[17]	2016	Y	19	11	8	53%	9.1	62
Heydar[14]	2017	Y	16	16	0	37.5%	7.83	62
Heydar[3]	2016	Y	18	18	0	39%	7.3	68
Yılmaz[18]	2016	Y	8	5	3	25%	10.6	---
Keskinen[16]	2016	Y	50	27	23	38.4%		55.2
Hosseini[15]	2016	N	23	15	8	29.2%	7.45	55.35
La Rosa[21]	2017	Y	10	10	0	50%	7.2	64.7
Teoh[11]	2016	Y	8	4	4	---	8.2	60
Rolton[22]	2016	Y	21	10	11	52%	7.8	54
Nnadi[23]	2018	Y	10	10	0	50%	6.2	57.7
Ridderbusch[5]	2017	Y	24	24	0	33%	8.9	63