Sublaminar bands: are they safe?

Sublaminar bands (SB) are frequently used as implants in spine deviation correction.

Our purpose is to demonstrate their safety on a large series of patients.

This is a retrospective study.

Our department treated 378 spine deviations on children and adolescents via a hybrid posterior technique (lumbar screws, hook and thoracic SB). Each surgery was undertaken using anesthesiologic and a neurophysiologic monitoring using somatosensory evoked potentials (SSEP) and neurogenic mixed evoked potentials (NMEP). An alert was described as an amplitude decrease of 50 % and/or a latency increase of 10 %. Data were analyzed using Student or Wilcoxon tests.

We used 2,223 SB in 378 operative procedures. We described ten neurophysiologic alerts during the passage of the band under the lamina. There were no significative differences between the two groups concerning the age and the severity of the deformation (p > 0.05). These neurophysiologic alerts were associated with a dysautonomic trouble (hypertension and bradycardia). The lesional level was determined using a spinal electrode. In six cases, the responsible SB was removed. Three patients had post-operative neurologic deficiency (0.8 %) without complete recovery for one of them (localized incomplete sensitive deficiency). Within the group of 378 patients, 21 alerts were reported due to a screw or a hook, or during the correction manoeuver, without dysautonomic trouble.

SB neurologic complications rate is as high as other implants' complication rate. Simultaneous hemodynamic and neurophysiologic change is an argument for vegetative response due to SB passage. Their optimal use requires a strict learning of their insertion under the lamina to be as less traumatic as possible. SB are as safe as any other spine implants.