Instrumentation failure following pediatric spine deformity growth-sparing surgery using traditional growing rods or vertical expandable prosthetic titanium ribs

Table 2 Timing of instrumentation failure in traditional growing rod technique

	Index surgery	Lengthening surgery				P for trend
	Index surgery	1st–3rd	4th–6th	7th–9th	≥ 10th	P for trend
No. of surgeries	58	173	154	99	60	-
No. of IFs (%)	4 (6.9)	11 (6.4)	7 (4.5)	2 (2.0)	0 (0)	0.01*
No. of anchor loosenings/dislocations (%)	4 (6.9)	5 (2.9)	4 (2.6)	2 (2.0)	0 (0)	0.23
No. of rod breakages (%)	0 (0)	5 (2.9)	3 (1.9)	0 (0)	0 (0)	0.04*
No. of connector breakages (%)	0 (0)	1 (0.6)	0 (0)	0 (0)	0 (0)	0.28

IF: instrumentation failure
*Statistically significant association between the number of lengthening surgeries performed and the surgery-based incidence of IF in the Cochran–Armitage test

ISSN: 1471-2474