Anterior and posterior spinal fusion: comparison of one-stage and two-stage procedures

Abstract

Objective: To compare postoperative morbidity and length of hospital stay after combined anterior and posterior spinal fusion for patients treated by a one-stage procedure and those treated in two stages, 1 to 2 weeks apart.

Design: Retrospective review of all cases handled by the first author between July 1989 and November 1991. The patients had been referred for treatment of severe spinal deformity, scoliosis or kyphosis by combined anterior and posterior spinal fusion.

Setting: The operations were performed at McMaster University Medical Centre, Hamilton, Ont., by the first author, who was assisted by another specialist in spinal surgery and a fellow or resident.

Patients: Eleven operations of each type were performed. The mean age of the 22 patients was 16.6 and 14.6 years for those who underwent the one-stage and the two-stage procedures respectively. The diagnoses included neuromuscular disease, neurofibromatosis, spina bifida, congenital kyphoscoliosis and severe idiopathic spinal curvature. The one-stage procedure was used after the surgical team became able to provide the care associated with this type of major surgery; selection of patients also involved preoperative risk assessment and the feasibility of combining two surgical procedures that would take a maximum of 9 hours. The preoperative plan was to spend a maximum of 9 hours in performing the one-stage procedure.

Interventions: Similar surgical procedures were performed in both groups. The average number of intervertebral levels fused during the anterior component of the operation was 4.6 in the one-stage procedure and 6.0 in the two-stage procedure. Thoracolaparotomy was performed in four patients who underwent the two-stage procedure. During the posterior component of the operation, instrumentation was inserted through an average of 11.6 and 12.6 intervertebral levels in the groups undergoing the one-stage and the two-stage procedures respectively. Total operating time averaged 7 hours and 15 minutes for the one-stage procedure and 11 hours for the two-stage procedure. Mean blood loss was 1830 mL for the one-stage procedure and 2270 mL for the two-stage procedure.

Main outcome measures: The number of days spent in the intensive care unit (ICU) and the total number of days spent in hospital, as well as morbidity after the operation, were determined.

Results: Postoperative morbidity included five minor complications in patients who underwent a one-stage procedure; all of these complications resolved well. Among those who underwent the two-stage procedure there were 11 complications; in two patients further surgery was required. The patients' stay in the ICU averaged 2.6 and 7.7 days respectively for one-stage and two-stage procedures, and the total stay in hospital averaged 14 and 33 days respectively.

Conclusions: When possible, the one-stage procedure for anterior and posterior spinal fusion is preferred over the two-stage procedure because of a significant reduction in the length of stay in the ICU and in hospital, as well as reduced morbidity. However, this analysis should be interpreted cautiously because of the small number of cases and the variables encountered in treating this type of spinal deformity.