Editorial: Minimally invasive spinal surgery and spinal stenosis

Modified minimally invasive-transforaminal lumbar interbody fusion under microscopic view to achieve bilateral decompression and fusion through a single approach to treat developmental lumbar spinal stenosis

PURPOSE

To describe a modified minimally invasive spine (MIS) procedure to treat lumbar developmental spinal stenosis (DSS) to achieve complete decompression and fusion. The method preserves the muscles, ligaments, and most of the bony structures. DSS is not considered a good indication for MIS procedures and few reports discuss alternative treatments. Because MIS has the advantages of low blood loss, rapid recovery, and short hospital stay, it would be ideal for DSS.

METHODS

After confirming the screw positions, we placed a tube retractor in the facet joint on the decompressed side. The inferior facet joint and part of the superior joint of the lower segment were removed, the spinal canal was carefully exposed under a microscopic view, and fusion was performed through Kambin's triangle. Next, the operation table was rotated to the contralateral side and angled to approximately 15-20 degrees. We then tilted the tube retractor in the facet joint toward the operation side by 15-20 degrees, which provided access to the contralateral canal for decompression. The ligament flavum was carefully removed and the dural sac was gently retracted to expose the lateral recess on the other side. We then examined the nerve root on the contralateral side to ensure there was no compression.

RESULTS

Eight patients with lumbar DSS were treated using this method. Patients' neurological symptoms improved greatly without complications and patients were able to walk the day after surgery. The inner plate of the contralateral lamina and muscle as well as most of the ligaments that contribute to stability were preserved.

CONCLUSION

This modified MIS decompression procedure successfully treated DSS by providing spinal canal decompression and preserving most of the stabilizing structures.

EFFICACY OF THE CLINICAL-INSTRUMENTAL ALGORITHM IN THE TREATMENT OF SPINAL TANDEM STENOSIS

ABSTRACT Objective: To conduct a multicenter analysis of the effectiveness of surgical tactics for treating patients with symptomatic tandem stenosis of the cervical and lumbar spine, based on a differentiated clinical-instrumental algorithm. Methods: The study included 97 patients with symptomatic tandem stenosis of the cervical and lumbar spine. The patients were allocated into 2 groups. The main prospective follow-up group (Group I) consisted of patients (n=46) who had undergone staged decompression/stabilization surgery according to the surgical tactics developed based on the differential clinical-instrumental algorithm. The clinical comparison group (Group II) (n=51) consisted of retrospectively recruited patients who, depending on the prevailing clinical condition, underwent primary surgery at the cervical level (29 cases) or at the lumbar level (22 cases). Results: The comparative analysis in Group I revealed significantly better parameters in the clinical and instrumental data. The total rates of postoperative surgical complications in the cervical and lumbar spine were 15% in Group I and 68% in Group II (p=0.0014). Conclusion: The multicenter analysis of the clinical-instrumental algorithm based on differential application of decompression/stabilization techniques enabled more rational and radical surgery, with less adverse outcomes, leading to earlier start of rehabilitation in the prospective group of patients (Group I), and an objective improvement in long-term clinical and functional outcomes. Level of Evidence II; Prognostic Studies - Investigating the Effect of a Patient Characteristic on Disease Outcome.

Upright MRI after decompression of spinal stenosis and concurrent spondylolisthesis

OBJECTIVEThe treatment of patients with spinal stenosis and concurrent degenerative spondylolisthesis is controversial. Two large randomized controlled clinical trials reported contradictory results. The authors hypothesized that a substantial number of patients will show evidence of micro-instability after a sole decompression procedure.METHODSThis study was a retrospective analysis of all cases of lumbar spinal stenosis treated at the Frankfurt University Clinic (Universitätsklinik Frankfurt) from 2010 through 2013. Patients who had associated spondylolisthesis underwent upright MRI studies in flexion and extension for identification of subtle signs of micro-instability. Clinical outcome was assessed by means of SF-36 bodily pain (BP) and physical functioning (PF) scales.RESULTSA total of 21 patients were recruited to undergo upright MRI studies. The mean duration of follow-up was 65 months (SD 16 months). Of these 21 patients, 10 (47%) showed signs of micro-instability as defined by movement of > 4 mm on flexion/extension MRI. Comparison of mean SF-36 BP and PF scores in the group of patients who showed micro-instability versus those who did not showed no statistically significant difference on either scale.CONCLUSIONSThere seems to be a substantial subset of patients who develop morphological micro-instability after sole decompression procedures but do not experience any clinically significant effect of the instability.