Significant practice variation exists in growing rod treatment, but there is some consensus on indications for surgery including curve size, diagnosis and age, and lengthening intervals and final fusion methods. Mean curve size and lengthening interval are greater in practice than in surgeons' stated aims. In principle and in practice, most growing rods are used for curves over 60 degrees in patients under 10, in all diagnoses. This information may form a starting point as practice variation is studied.

Patients with thoracic hyperkyphosis present even more of a challenge with respect to complications, specifically implant-related complications. Our study shows that growing rod surgery in patients with kyphosis more than 40° has significantly more general and implant complications than that in patients with normal thoracic kyphosis. Implant complications were more common in hyperkyphotic (>40°) patients and increased linearly with increasing kyphosis. The most common implant complication was rod breakage. Patients with hyperkyphotic thoracic spines, particularly syndromic patients, must be monitored closely and parents should be counseled regarding the likelihood of future adverse events.

Risk factors for rod fractures include prior fracture, single rods, stainless steel rods, small diameter rods, proximity to tandem connectors, short tandem connectors, and preoperative ambulation. Repeat fractures are common, especially with single rods. Rod replacement, with larger diameter rods if appropriate, may be a preferred strategy over connecting the broken rods as fractures signal fatigue of the rod.

BackgroundA single iliosacral screw placed into the S1 vertebral body has been shown to be clinically unreliable for certain type C pelvic ring injuries. Insertion of a second supplemental iliosacral screw into the S1 or S2 vertebral body has been widely used. However, clinical fixation failures have been reported using this technique, and a supplemental long iliosacral or transsacral screw has been used. The purpose of this study was to compare the biomechanical effect of a supplemental S1 long iliosacral screw versus a transsacral screw in an unstable type C vertically oriented sacral fracture model.Materials and methodsA type C pelvic ring injury was created in ten osteopenic/osteoporotic cadaver pelves by performing vertical osteotomies through zone 2 of the sacrum and the ipsilateral pubic rami. The sacrum was reduced maintaining a 2-mm fracture gap to simulate a closed-reduction model. All specimens were fixed using one 7.0-mm iliosacral screw into the S1 body. A supplemental long iliosacral screw was placed into the S1 body in five specimens. A supplemental transsacral S1 screw was placed in the other five. Each pelvis underwent 100,000 cycles at 250 N, followed by loading to failure. Vertical displacements at 25,000, 50,000, 75,000, and 100,000 cycles and failure force were recorded.ResultsVertical displacement increased significantly (p < 0.05) within each group with each increase in the number of cycles. However, there was no statistically significant difference between groups in displacement or load to failure.ConclusionsAlthough intuitively a transsacral screw may seem to be better than a long iliosacral screw in conveying additional stability to an unstable sacral fracture fixation construct, we were not able to identify any biomechanical advantage of one method over the other.Level of evidenceDoes not apply—biomechanical study.

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