Posterolateral lumbar fusion using facet joint fixation with biodegradable rods: A pilot study

Abstract

Roentgen stereophotogrammetric analysis (RSA) was used to assess whether there is a potential for biodegradable rods crossing the denuded facet joints to increase the stability and healing rate of lumbar posterolateral fusions. Eleven consecutive patients with lumbosacral disc/facet joint degeneration had a posterolateral fusion augmented with 2-or 3.2-mm biodegradable rods passing perpendicularly through the center of the denuded facet joints. The patients were followed-up with RSA in supine and erect positions monthly from the 2nd to the 6th postoperative month, and again 1 year postoperatively. All seven L5-S 1 fusions healed. Four cases were stable as defined by RSA within 3 months, two within 6 months, and one within 1 year. One L4-S 1 fusion could not be evaluated by RSA.None of the remaining three L4-S 1 fusions fully healed. In all three cases 1-to 3-mm intervertebral translations remained at 1 year. None of the 11 fusions showed any radiographic signs of osteolysis around the biodegradable rods. The promising results of this pilot study indicate that posterolateral L5-S 1 fusion augmented with transarticular biodegradable rods crossing the denuded facet joints may yield rapid intervertebral stabilization and a high healing rate without any adverse rod effects. This may be due to enhanced initial fusion stabilization and/or increased ossification induced by the rods.

A semi-automated method using interpolation and optimisation for the 3D reconstruction of the spine from bi-planar radiography: a precision and accuracy study

“…in lying posture (SD under 1° [1]). Roentgen Stereophotogrammetric Analysis (RSA) is another threedimensional technique, precise when using implanted metal markers (SD under 0.7° [37,38]). But the procedure is invasive, requires specific radiographs (i.e., other than frontal and sagittal) and gives only access to the relative motion of the vertebrae.…”

Lumbar Intervertebral Instability: A Review

“…The relative movements of marked vertebrae, induced by positional changes from flexion to the neutral position in the supine spine, can be calculated with repeated radiographic examinations and computer analysis. The RSA accuracy determined from the results of repeated radiographic examinations has amounted to a standard deviation of 0.7°, 0.2°, and 0.3°for rotatory motion around the transverse, vertical, and sagittal axes, respectively, and to a standard deviation of 0.2 mm for translatory motion along these axes (101,102). RSA has proved to be the best method to detect very small movements between vertebrae (91,101,102); unfortunately, this method is technically difficult, time consuming, and requires specific apparatus.…”

“…The RSA accuracy determined from the results of repeated radiographic examinations has amounted to a standard deviation of 0.7°, 0.2°, and 0.3°for rotatory motion around the transverse, vertical, and sagittal axes, respectively, and to a standard deviation of 0.2 mm for translatory motion along these axes (101,102). RSA has proved to be the best method to detect very small movements between vertebrae (91,101,102); unfortunately, this method is technically difficult, time consuming, and requires specific apparatus. Moreover, because of its invasive nature, it is unsuitable for studies of large patient series.…”

Degenerative lumbar intervertebral instability: what is it and how does imaging contribute?

“…However, the reported results are not really convincing, and despite continuous development of MR imaging equipment, essential problems still arise during attempts to perform examinations in upright posture for patients with spinal disorders [27,28]. The overall examination time created severe pain problems.…”

“…Radiostereometric analysis (RSA) has been proven to be the best method to evaluate three-dimensional translatory and rotatory motion between vertebrae [28]; unfortunately, this method is technically difficult, time-consuming, and requires specific apparatus. Moreover, because of its invasive nature, it is unsuitable for studies of large patient series.…”