Influence of Posture on Gait Parameters in Severe Symptomatic Lumbar Stenosis Before and After Decompression Surgery.

BACKGROUND: We searched to quantify the influence of sagittal vertical axis (SVA) on the improvement of spatiotemporal gait parameters using a gait motion analysis (GMA) before and after decompression surgery in patients suffering from lumbar spinal stenosis (LSS). METHODS: Thirty-nine patients with severe LisSS planned for lumbar decompression underwent a full-body biplanar radiographs (EOS) to quantify the SVA and have benefited from a 3-dimensional GMA 1 month before surgery (M0) and 6 month (M6) after surgery. The first step of this study was to confirm the validation of 3-dimensional sagittal vertical axis (3D SVA) for posture analysis. An analysis of modification of the 3D SVA and spatiotemporal gait parameters was then carried out in order to identify any correlation. RESULTS: Decompression surgery did not significantly improve 3D SVA between M0 and M6 (respectively 49.1 [50.3] vs. 49.84 [19.02], P = 0.42). Concerning spatiotemporal parameters, we found significant difference for all parameters between M0 and M6. A strong correlation (R2 > 0.65) between static SVA (EOS) and 3D SVA was demonstrated using a statistical regression equation. There was also a statistically significant correlation between SVA (static and 3-dimension) and improvement in spatiotemporal gait parameters after decompression surgery. CONCLUSIONS: This study analyses the relationship between postural change (SVA) and improvement in gait parameters measured during GMA before and after decompression surgery for LSS. This specific analysis of gait parameters may represent a prognostic assessment tool for the recovery of patients undergoing surgery for a LSS.

Rare Complication of Percutaneous Technique: Intradural Cement Leakage and Its Surgical Treatment.

Popularity of percutaneous vertebroplasty and vertebral augmentation to treat vertebral compression fractures is increasing. Cement leakages are relatively common, but intradural cement leakage is rare. Few cases of intradural cement leakage have been reported in the literature, and emergency surgery has been reported to be <1%. A 64-year-old man with osteolytic vertebral compression fracture at L1, caused by a malignant tumor, had undergone a vertebral augmentation by craniocaudal procedure. Neurologic examination after the surgery revealed paralysis in both legs immediately postoperatively. Computed tomographic imaging revealed a large cement leakage into the spinal canal. The patient was referred to our department for emergency management. He was rapidly scheduled for surgical decompression by laminectomy. First, stabilization by a secure posterior short fixation was done. The laminectomy showed that insertion of a needle through the pedicle had breached the dura and had caused intradural cement leakage. As shown in the Supplementary Video, the piece of intradural cement was finally removed after posterior durotomy. This case demonstrates that even if percutaneous vertebroplasty is a relatively safe technique, it should be performed by well-trained physicians and with great care to prevent disabling complications.

Surgeon's and patient's radiation exposure during percutaneous thoraco-lumbar pedicle screw fixation: A prospective multicenter study of 100 cases.

HYPOTHESIS: Percutaneous pedicle screw fixations (PPSF) are increasingly used in spine surgery, minimizing morbidity through less muscle breakdown but at the cost of intraoperative fluoroscopic guidance that generates high radiation exposure. Few studies have been conducted to measure them accurately. MATERIAL AND METHODS: The objective of our study is to quantify, during a PPSF carried out in different experimented centers respecting current radiation protection recommendations, this irradiation at the level of the surgeon and the patient. We have prospectively included 100 FPVP procedures for which we have collected radiation doses from the main operator. For each procedure, the doses of whole-body radiation, lens and extremities were measured. RESULTS: Our results show a mean whole body, extremity and lens exposure dose per procedure reaching 1.7±2.8µSv, 204.7±260.9µSv and 30.5±25.9µSv, respectively. According to these values, the exposure of the surgeon's extremities and lens will exceed the annual limit allowed by the International Commission on Radiological Protection (ICRP) after 2440 and 4840 procedures respectively. CONCLUSION: Recent European guidelines will reduce the maximum annual exposure dose from 150 to 20mSv. The number of surgical procedures to not reach the eye threshold, according to our results, should not exceed 645 procedures per year. Pending the democratization of neuronavigation systems, the use of conventional fluoroscopy exposes the eyes in the first place. Therefore they must be protected by leaded glasses. LEVEL OF PROOF: IV, case series.

Improvement in Sagittal Balance After Decompression Surgery without Fusion in Patients with Degenerative Lumbar Stenosis: Clinical and Radiographic Results at 1 Year.

OBJECTIVE: To evaluate modifications in static spinal status after posterior decompression surgery without fusion in patients with symptomatic central canal stenosis. METHODS: From November 2014 to May 2016, 72 patients who underwent isolated decompression for lumbar spinal stenosis were enrolled prospectively in this single-center study. All of the patients had lateral full-body x-ray scans with the EOS system (EOS Imaging, Paris, France) before surgery and after 12 months of follow-up. Patients were classified into 3 groups according to their preoperative sagittal vertical axis (<50 mm, ≥50 mm, and <100 mm, ≥100 mm). RESULTS: SVA decreased significantly (SVA preoperative: 72.3 ± 43.1; SVA postoperative: 48.3 ± 46.8. P < 0.001). Lumbar lordosis increased significantly from 41.9 ± 13.4 in the preoperative period to 46.5 ± 14.8 at the last follow-up (P < 0.001). In the imbalance groups, the mean postoperative SVA decreased significantly compared with preoperative SVA (P = 0.004). Surgery led to a significant increase in lumbar lordosis in the 3 groups (P < 0.05). Nonetheless, a certain degree of residual imbalance persisted in the major imbalance group. In all of the groups, decompression surgery led to a significant improvement in clinical scores (P < 0.05). CONCLUSIONS: Our study showed an improvement in sagittal balance and lumbar lordosis after decompression surgery without fusion, even in patients with a preoperative SVA >100 mm. However, a certain degree of sagittal imbalance may persist after surgery in patients with major initial imbalance (SVA >100 mm). Nonetheless, after surgery, these patients experienced a clinical benefit comparable with that in the other groups.

Stand-alone ALIF with integrated intracorporeal anchoring plates in the treatment of degenerative lumbar disc disease: a prospective study on 65 cases.

PURPOSE: ALIF with cages is expected to restore disc height and stabilize the spine promoting fusion, while avoiding damage attributed to rod-pedicle screw fixation. However, it may be related to an increased risk of fusion failure and subsidence. A prospective study was conducted by five investigators across three centers to confirm performance of a PEEK cage for stand-alone ALIF in the treatment of lumbar degenerative disc disease (DDD). METHODS: Sixty-five patients, with back ± leg pain, requiring surgery for DDD, were included. Efficacy and safety were evaluated at 6 weeks, 3, 6, and 12 months post-operatively. Fusion and subsidence were assessed through CT-images at 12-month follow-up. Disc height was measured. Clinical outcomes included back and leg pain (VAS), disability (Oswestry Disability Index), Quality of Life (Short-Form 36), and adverse events. RESULTS: The fusion and the subsidence rates were 96.3 and 2.0 %, respectively. ALIF surgery restored anterior and posterior disc height compared to baseline. There were no device-related serious adverse events, and no revision surgeries. Clinical outcomes improved significantly through 12-month follow-up. CONCLUSION: Safety and efficacy of this stand-alone cage with integrated intracorporeal plates was confirmed through 12 months for treatment of degenerative conditions. The design of the cage and plates may contribute to the decreased subsidence rate observed.

Radiological analysis of 37 segments in cervical spine implanted with a peek stand-alone device, with at least one year follow-up.

BACKGROUND: High incidence of subsidence in cervical stand-alone cages was reported in the literature. PURPOSE: The goal of this study was to assess the radiological outcomes of a PEEK anchored stand-alone cage (MC+®) with a minimum of 1 year follow-up. STUDY DESIGN: A retrospective radiological evaluation. PATIENT SAMPLE: The study was conducted in 4 hospitals and involved 28 patients (37 levels) treated by ACDF (Anterior Cervical Discectomy and Fusion) for spondylotic radiculopathy and/or myelopathy. OUTCOME MEASURES: We analyzed fusion, disc height, cage or anchor micro plate migration, discal and segmental lordosis and subsidence. METHODS: All the patients were controlled at least one year after surgery with an average of 31 months. Antero-posterior and lateral X-rays were performed pre-operatively, immediate post-operatively, and at final follow up. The different radiographic measurements were performed with the assistance of software (SpineView®). CT-scans were performed for each case at final follow-up to assess the fusion. RESULTS: No migration or breakage was reported for either the cage or the anchor micro plate. The fusion rate was 94.1% at the final follow-up. No subsidence was observed. The disc height increased between preop and final follow-up from 23.3% to 44.3%, from 22.1% to 35.1% and from 38.3% to 51.5% for anterior, posterior and midline disc height respectively. Mean Functional Spinal Unit Lordosis increased from 0.9° preop to 3.0° at final follow-up. No new kyphotic situation could be noticed. At the final follow-up, 96% of the patients stated they would undergo the procedure again. CONCLUSION: With a high rate of proven fusion, restoration of disc height and spinal alignment in most cases, and absence of subsidence or migration, our radiological results with MC+® at more than 1 year of follow-up show the implanted device to be safe and effective for use in treating degenerative conditions of the cervical spine.