Pedicle-Lengthening Osteotomy for the Treatment of Lumbar Spinal Stenosis: the Surgical Technique (Pilot Clinical Study)

Abstract

Stenosis of the lumbar spine is a common degenerative disease; its progression leads to a significant restriction in daily activities and quality of life. This pilot study presents a novel minimally invasive technology for surgical correction of lumbar stenosis; the technique involves a widening of the spinal canal and intravertebral foramen by percutaneous bilateral osteotomy of the vertebral pedicles and their subsequent lengthening. Materials and Methods. Twenty patients with symptomatic lumbar stenosis were included in this prospective study (11 of them with stable anterolisthesis grade I). The patients underwent percutaneous osteotomy with lengthening of the vertebral pedicles at one or two levels. X-ray results were obtained from either standard radiography or computed tomography of the lumbar spine. The baseline patients' condition and the clinical outcomes of the surgical treatment were assessed using a number of validated examination tests, including the Oswestry Disability Index (ODI), the Zurich Claudication Questionnaire (ZCQ), the 10-mm visual-analogue pain scale (VAS), the SF-12 nonspecific quality of life questionnaire (version 2) with the physical (PCS) and mental (MCS) component summary scores. The minimal period of postoperative follow-up was 78 months (6.5 years). Results. In all cases of surgical interventions, the percutaneous osteotomy proceeded without complications and with a minimal blood loss. As compared with the preoperative period, the patients' quality of life (according to ODI) significantly improved from 48 to 15.5 points over 12 months (p=0.0002) and 5 years (p=0.0004), and up to 20 points in 6 and more years (p=0.0001). The SF-12 test also showed a statistically significant improvement in the quality of life throughout the observation period, with the exception of the MCS score taken soon (6 weeks) after the surgery. The pain syndrome (according to VAS) significantly diminished both in the back and in the lower extremityfrom the preoperative 5.8 and 7.4 points to 2.25 and 0.05 points after 5 years (p=0.0004). However, after 6 years or more, the pain syndrome again increased to 3.2 and 2.4 points, respectively, but remained significantly better than that in the preoperative period (p=0.04 and p=0.0006, respectively). According to the ZCQ questionnaire, the patients' condition improved from 2.0 points (6 weeks after surgery) to 1.5 points at 12 months (p=0.01) and to 1.67 after 5 years (p=0.011). However, after 6 years or more, the value of ZCQ increased to 1.83 points, which did not significantly differ from the preoperative level (p=0.14). Conclusion. Percutaneous bilateral osteotomy of the vertebral pedicles followed by their lengthening in patients with symptomatic lumbar spinal stenosis (including stable spondylolisthesis grade I) is a promising innovative technology. This minimally invasive treatment is beneficial primarily for elderly patients and those suffering from comorbidity. The results of this pilot study followed up for more than 6 years indicate a good immediate and...