Modified posterior vertebral column resection for severe spinal deformity: a retrospective, comparative study.

BACKGROUND CONTEXT

Posterior vertebral column resection (PVCR) has several advantages over a combined anterior-posterior procedure for management of severe, rigid spinal deformities. The technique, described by Suk et al., has a high complication rate. Modifications of the technique which can reduce this complication rate might make this challenging procedure safer.

PURPOSE

To report the results of PVCR in severe, rigid spinal deformity; to describe a modified technique for PVCR and compare its results with the conventional technique.

STUDY DESIGN

Retrospective cohort.

PATIENT SAMPLE

A total of 38 patients who underwent PVCR for severe, rigid spinal deformities.

OUTCOME MEASURES

Mean correction of deformity (sagittal and/or coronal), estimated blood loss, operation time, neurological and non-neurological complications, patient-reported outcome score (SRS-22r).

METHODS

Thirty-eight patients underwent PVCR for severe, rigid spinal deformities. These patients had a deformity in excess of 90° and a flexibility index <20%. Twenty-one of 38 patients (Group 1) underwent PVCR by the technique reported by Suk et al.; 17 patients (Group 2) underwent a modified PVCR technique. Our technique involves retaining the posterior elements until the other steps of PVCR are completed, which prevents ventral settling and allows for less handling of an already tight spinal cord. The results and complications were compared between the two groups.

RESULTS

The mean operating time was 251 minutes and the mean blood loss was 1,251 mL. Mean coronal correction of 50% and a mean sagittal correction of 52.4% were achieved. Intraoperative loss of motor evoked potentials was seen in eight patients while there were two instances of permanent postoperative deficit, both occurring with the conventional PVCR technique. The average operating time, mean correction and blood loss did not differ between the two techniques. There was, however, a reduction in the occurrence of neurological complications with the authors' modified technique.

CONCLUSIONS

Our retrospective study with a small cohort suggests that the authors' modified technique of PVCR, wherein the posterior elements are preserved until just prior to attempting to correct the deformity, may be safer in terms of neurological complications when compared with the conventional technique. However, larger studies are warranted to conclusively establish this.