Congenital agenesis of lumbo-sacral pedicles with associated anomalies: case report with an emphasis on the use of O-arm, navigation in the management with literature review

Abstract

Background

Congenital spinal pedicle agenesis is rare. The majority of cases are asymptomatic. Few present with either low back pain or radiculopathy. Pedicle screw insertion may pose difficulties in view of abnormal anatomy.

Case presentation

Between Jan 2005 and March 2021, all the data were retrospectively reviewed for the cases operated for congenital anomalies. Three such cases were operated. Case 1 had bilateral agenesis of L5 vertebra with an ectopic kidney in right iliac fossa, absent uterus, absent ovaries and vaginal atresia. Case 2 had absent S1 pedicle with conjoint left L5 nerve root. Case 3 had hypoplastic left L5 pedicle, contained disc herniation, facetal arthropathy. Pedicle screws were placed using O-arm and navigation.

Conclusion

Pedicle agenesis increases the difficulty in pedicle screw fixation and fusion. Anomalous facet and conjoint nerve root need to be looked for intraoperatively. Use of O-arm and CT navigation is of great help in getting safe and accurate anchor points for screw placement avoiding neurological injury.