Table 2.

Device-related complications for internal lengthening devices.

Device-related complications	Description
(I) Distraction control-related	Problem like this can primarily prevent the lengthening target from being met or causes regenerate problems
	Runaway, difficult to distract nail, running back, nondistracting nail
	(a) Problem/(b) obstacle/(c) sequela
(II) Stability related	Problem like this will primarily cause secondary deformity, instability of the bone or limited weight bearing
	Nail bending/breakage, rotational instability
	(a) Problem/(b) obstacle/(c) sequela
(III) Other device-related	Device problems that in principle do not affect the primary functions of the device
	Corrosion, adverse reaction of tissue
	(a) Problem/(b) obstacle/(c) sequela