Camille's transarticular technique of spinal fixation: An underused surgical technique.

Segmental spinal fixation techniques have developed over the years, from sublaminar wire fixation and wire and metal loop fixation to facetal and pedicular screw fixation. Literature survey suggests that polyaxial pedicular screw and rod fixation for lumbar spine and facetal screw and rod fixation technique for subaxial cervical spinal fixation are the more popularly adopted surgical techniques. Pedicular screw fixation for cervical spine is progressively becoming popular. Transarticular screw fixation technique described by Roy-Camille and Saillant in 1972 has been used by a number of surgical groups.[1] However, our general assessment is that despite the safety, effectiveness, and ease of insertion of transarticular screws, this technique has not got its place of pride in the fixation armamentarium of spine.

Bone material-wise facets are the thickest and strongest part of the vertebra. Facets are thick blocks of bones placed one above the other and constitute the central weight-bearing axis or plinth of the spine. All the major muscles of the spine are located in the posterior and lateral aspect of the vertebral column and act with their fulcrum on the facetal articulation. Intervertebral disc coordinates the movements by virtue of the strength of its 'incompressible fluid' content. No major muscle of the spine is located in the vicinity of the disc. The disc essentially is like an opera conductor who runs the entire show without playing any instrument.[2]

The oblique articular surface of the facets provides a unique pattern of movements by telescoping of one facet over the other. Muscles attached to the transverse processes essentially cater to rotatory movements. Any weakness of muscles related to their disuse, abuse, or injury could lead to instability of the spine that is first manifested at the facets. Our several articles on the subject identify vertical spinal instability or listhesis of facets as the primary and nodal point of pathogenesis of the entire process of spinal degeneration.[3456789]

Transarticular facetal fixation using screws stabilizes the spine at the fulcrum of its movements, a feature that appears crucial in effective obstruction of all spinal movements. Transarticular traverse of screws provides “zero” movement situation that forms an ideal situation for arthrodesis of the joint. Despite the possibility of introducing long screws in pedicular fixation technique, the advantage of entirely blocking the movements at the articulation as in transarticular technique is not present. The thick and largely cortical facets provide a strong purchase ground for screws.[8910] Appropriately directing the screws is a safe, simple, and quick surgical procedure. The laterally directed screw is safe for the vertebral artery in cervical spine and for the roots in both cervical and lumbar spines.

We recently discussed the possibility of introducing two (double insurance) or three (triple insurance) screws in a transarticular fashion in a single cervical or lumbar articulation [Figure 1]. Introduction of more than one screw adds strength to the fixation technique. The very fact that more than one screw can be inserted into an articulation is suggestive of the large host area and safety of the surgical procedure.

Figure 1

(a) Lateral radiograph showing the transarticular screw fixation. (b) Anteroposterior radiograph showing the double insurance transarticular screws

Although there are several articles in the literature that discuss superiority of one technique over the other, our general observation is that the transarticular technique is superior in strength of screw purchase, ease of performance under direct vision without the need for any radiographic monitoring, and significantly quick when compared to all the other discussed techniques. As the screw traverses through the joint and violates the articular surface and cartilage, it provides an opportunity for early bone fusion.

Our experience suggests that Camille's technique of transarticular screw fixation should become the primary spinal segmental fixation technique, a place that it richly deserves.