Double insurance transfacetal screws for lumbar spinal stabilization

Abstract

Aim:The authors report experience with 14 cases where two screws or “double insurance” screws were used for transfacetal fixation of each joint for stabilization of the lumbar spinal segment. The anatomical subtleties of the technique of insertion of screws are elaborated.Materials and Methods:During the period March 2011 to June 2014, 14 patients having lumbar spinal segmental instability related to lumbar canal stenosis were treated by insertion of two screws into each articular assembly by transfacetal technique. After a wide surgical exposure, the articular cartilage was denuded and bone chips were impacted into the joint cavity. For screw insertion in an appropriate angulation, the spinous process was sectioned at its base. The screws (2.8 mm in diameter and 18 mm in length) were inserted into the substance of the medial or inferior articular facet of the rostral vertebra via the lateral limit of the lamina approximately 6–8 mm away from the edge of the articular cavity. The screws were inserted 3 mm below the superior edge and 5 mm above the inferior edge of the medial (inferior) facets and directed laterally and traversed through the articular cavity into the lateral (superior) articular facet of the caudal vertebra toward and into the region of junction of base of transverse process and of the pedicle. During the period of follow-up all treated spinal levels showed firm bone fusion. There was no complication related to insertion of the screws. There was no incidence of screw misplacement, displacementor implant rejection.Conclusions:Screw insertion into the firm and largely cortical bones of facets of lumbar spine can provide robust fixation and firm stabilization of the spinal segment. The large size of the facets provides an opportunity to insert two screws at each spinal segment. The firm and cortical bone material and absence on any neural or vascular structure in the course of the screw traverse provides strength and safety to the process.

Lumbar canal stenosis: analyzing the role of stabilization and the futility of decompression as treatment

“…Our more than 30-year experience of manipulating the facets, initially of the craniovertebral junction and later of subaxial spine, has placed us in an advantageous position to identify the status of stability of the spinal segment. 10,11,13 With clinical and radiological guidance, the instability of the lumbar spinal segments was diagnosed by direct physical observation and manual manipulation of bones. 5 Transarticular fixation performed using 2 or 3 screws was identified to be safe, simple, and quick, and it is an effective technique of stabilization that works at the site of the fulcrum of spinal movements at the facet joint.…”

“…21 Double insurance, or 2 screws placed in a transarticular fashion, a modification of Roy-Camille's technique that was described by us earlier, was used in all patients. 13 In 8 patients, 3 screws (triple insurance) were used in a transarticular fashion in at least one of the facetal articulations. The self-tapping monoaxial screws were approximately 18 mm long and 2.6 mm in diameter.…”

“…On the basis of the concept that spinal instability is the core issue, we performed only stabilization of spinal segments without resorting to any kind of bone, soft-tissue, disc, or osteophyte resection for single-or multilevel spinal degeneration for both cervical and lumbar spines. 8,10,11,[13][14][15] In this presentation we analyze the surgical results in 70 cases diagnosed with lumbar canal stenosis that were treated by fixation only. No decompression of any kind was done.…”

Preliminary Experience with a Novel System of Facet Fixation to Treat Patients with Lumbar Degenerative Disease. A New Perspective in Minimally Invasive Spine Surgery?

“…After a midline skin incision, exposure of the spine was widened laterally, to expose the facets and the articular joint cavity. 7 After resecting the cartilage surface, the facet joint was mechanically blocked by inserting a titanium implant, strengthened by two self-locking screws. In the next step, the cartilaginous layers of the joint surfaces were resected and a reamer was used to remove the bone on the facet joint entry, to create a flat surface, allowing to insert the Facet Wedge optimally.…”

Degenerative Cervical Spondylosis- Is Instability the Primary Point of Pathogenesis?

“…We have now realized that 'only fixation' of the facets or the site of spinal movements is an ideal form of treatment for degeneration of spine [12][13][14]. We prefer transarticular facetal fixation [15,16]. This technique is safe, quick and rather straightforward and effective.…”