With the identification of literature shortfalls on the techniques employed in intraoperative navigated (ION) spinal surgery, we outline a number of measures which have been synthesised into a coherent operative technique. These include positioning, dissection, management of the reference frame, the grip, the angle of attack, the drill, the template, the pedicle screw, the wire, and navigated intrathecal analgesia. Optimizing techniques to improve accuracy allow an overall reduction of the repetition of the surgical steps with its associated productivity benefits including time, cost, radiation, and safety.

Cite this article: Bone Joint J 2020;102-B(3):371–375.

The syndromes associated with a narrow lumbar spinal canal are described and discussed. In thirteen cases two main groups were evident, the larger group having mainly backache and root pain, the smaller group having intermittent claudication. A method of recognising the narrow spinal canal on plain radiographs is described, and a comparison made with normal controls. The findings at operation are reported and the importance is emphasised of making a wide laminectomy for decompression. Our thanks are due to the neurosurgeons of the South-West Neurosurgical Unit, Mr G. L. Alexander, Mr D. G. Phillips and Mr A. Hulme, who kindly allowed us full use of their clinical notes. We would also like to thank Mr G. Banham for the reproductions, Mr E. Turnbull for the drawing and the secretarial staff for their patient co-operation