Effectiveness of Percutaneous Pedicle Screw Fixation for Traumatic Thoracolumbar Spine Fracture

Introduction: Surgical treatment of thoracolumbar fracture without neurological damage has resulted in better clinical and radiological outcome than conservative treatment. Traditional open approach is associated with extensive paravertebral muscle damage and postoperative morbidity so percutaneous pedicle screw fixation is highly valuable alternatives. Aims: to evaluate the efficacy and outcome of percutaneous pedicle screw fixation in the treatment of traumatic thoracolumbar fracture without neurological deficit. Methods: This study was conducted in Nepalgunj Medical College, Nepalgunj in a time span of one year; total of 40 patients were included and treated with percutaneous pedicle screw fixation and followed up for 6months. They were evaluated clinically and radiologically. Results: 40 patients with thoracolumbar fractures were managed with percutaneous pedicle screw fixation with a mean operative time of 77.30 min and intraoperative blood loss was 88.38ml. There was significant improvement in cobb’s angle (mean difference 13.92 degree), vertebral body height loss (mean difference 37.7%) and visual analogue scale (mean difference 3.55) postoperatively. These improvements remained statically significant at 6months follow up. Conclusion: Percutaneous pedicle screw fixation is safe, valid and effective treatment of thoracolumbar fracture without neurological deficit.

Medial Pedicle Pivot Point Using Preoperative Computed Tomography Morphometric Measurements for Cervical Pedicle Screw Insertion: A Novel Technique and Case Series

This study describes a new and safe freehand cervical pedicle screw insertion technique using preoperative computed tomography (CT) morphometric measurements as a guide and a medial pedicle pivot point (MPPP) during the procedure. This study included 271 pedicles at 216 cervical spine levels (mean: 4.75 pedicles per patient). A pedicle diameter (PD) ≥ 3.5 mm was the cut-off for pedicle screw fixation. The presence and grade of perforation were detected using postoperative CT scans, where perforations were graded as follows: 0, no perforation; 1, perforation < 0.875 mm; 2, perforation 0.875–1.75 mm; and 3, perforation > 1.75 mm. The surgical technique involved the use of an MPPP, which was the point at which the lines representing the depth of the lateral mass and total length of the pedicle intersected, deep in the lateral mass. The overall success rate was 96.3% (261/271, Grade 0 or 1 perforations). In total, 54 perforations occurred, among which 44 (81.5%) were Grade 1 and 10 (18.5%) were Grade 2. The most common perforation direction was medial (39/54, 72.2%). The freehand technique for cervical pedicle screw fixation using the MPPP may allow for a safe and accurate procedure in patients with a PD ≥3.5 mm.

Risk Factors of Unsatisfactory Robot-Assisted Pedicle Screw Placement: A Case-Control Study

Objective: To identify potential risk factors of unsatisfactory screw position during robot-assisted pedicle screw fixation.Methods: A retrospective analysis of robot-assisted pedicle screw fixation performed in Beijing Jishuitan Hospital from March 2018 to March 2019 was conducted. Research data was collected from the medical record and imaging systems. Univariate tests were performed on the potential risk factors (patient’s characteristics and surgical factors) of unsatisfactory screw position during robot-assisted pedicle screw fixation. For statistically significant variables in univariate tests, a logistic regression test was used to identify independent risk factors for unsatisfactory screw position.Results: A total of 780 pedicle screws placed in 163 robot-assisted surgeries were analyzed. The rate of perfect screw positions was 93.08%, and the unsatisfactory rate was 6.92%. In patients with severe obesity (body mass index ≥ 30 kg/m²) (odds ratio [OR], 2.459; 95% confidence interval [CI], 1.199–5.044; p = 0.014), osteoporosis (T ≤ -2.5) (OR, 1.857; 95% CI, 1.046–3.295; p = 0.034), and the segments 3 levels away from the tracker (OR, 2.216; 95% CI, 1.119–4.387; p = 0.022), robot-assisted pedicle screw placement has a higher risk of screw malposition.Conclusion: During robot-assisted pedicle screw placement for patients with severe obesity, osteoporosis, and segments 3 levels away from the tracker, vigilance should be maintained during surgery to avoid postoperative complications due to unsatisfactory screw position.

Cortical Bone Trajectory Pedicle Screw Fixation in Surgical Treatment of Monosegmental Pyogenic Lumbar Spondylodiskitis

Background and Study Object Pedicle screw fixation has been widely used in surgical treatment for infective lumbar spondylodiskitis to prevent instability and deformity. The cortical bone trajectory pedicle screw (CBTPS) fixation is a minimally invasive posterior spinal fixation system that runs from the pedicle's entry point of the caudiomedial region toward the cephalad-divergent direction. Successful results with CBTPS fixation have been reported to treat degenerative and osteoporotic spinal diseases. This study aims to investigate the clinical feasibility of CBTPS in the surgical treatment of pyogenic lumbar spondylodiskitis. Patient and Methods We retrospectively retrieved 20 consecutive patients from two academic centers who were surgically treated for monosegmental lumbar pyogenic spondylodiskitis. The primary surgical treatment was the anterior lumbar interbody fusion with decompression, debridement, and reconstruction using an autogenous iliac strut bone graft. One to 2 weeks after the primary surgery, patients underwent a second surgery for posterior instrumentation using conventional pedicle screws (CPS; group I) and CBTPS (group II). Radiographic parameters of the deformity angle at the fusion segment and clinical parameter of visual analog scale (VAS) scores were assessed preoperatively, postoperatively, and at the last follow-up. Results There were 10 patients in each group. The mean follow-up periods of groups I and II were 51.10 ± 6.95 and 28.60 ± 9.31 months, respectively. Intergroup analysis indicated the two groups area age-matched (p = 0.38), but initial C-reactive protein (CRP; mg/dL, p = 0.04), CRP normalization (months, p = 0.00), and follow-up duration (months, p = 0.00) were heterogeneous. Meanwhile, deformity angles (segmental lordosis) between the two groups were not significantly different preoperatively (p = 0.25), postoperatively (p = 0.13), and at last follow-up (p = 0.38). The intragroup analysis indicated a significant postoperative increase of lordosis in both group I and II (p = 0.00 and 0.04, respectively) with subsequent subsidence. Lordosis remained increased at the last follow-up with or without significance (group I, p = 0.02; group II, p = 0.62). Both groups showed significant improvement in VAS scores (group I, p = 0.00; group II, p = 0.00). Conclusion In monosegmental lumbar spondylodiskitis, posterior stabilization of the anterior strut bone graft by CBTPS and CPS was comparable via the radiographic parameter of segmental lordosis or deformity angle. Our observation suggests the clinical feasibility of CBTPS in the treatment of relatively mild monosegmental pyogenic lumbar spondylodiskitis.

The Hardware Failure and Correction Loss of Short-segment Pedicle Screw Fixation Combined With Transforaminal Interbody Fusion in Treatment of Unstable Thoracolumbar Burst Fracture: Retrospective Study in Vietnam

Background: Correction loss and hardware failure of short segment posterior pedicle screw fixation in treatment of thoracolumbar unstable burst fracture have been remaining a main concern. Several authors have introduced the procedures to solve these limitations including transforaminal interbody fusion (TIF). The purposes of this study were to evaluate the progressive kyphosis and implant failure of short-segment pedicle screw fixation combined with transforaminal interbody fusion in treatment of unstable thoracolumbar burst fracture.Methods: The retrospective study were enrolled in the patients with isolated unstable thoracolumbar burst fractures, Denis type IIB who were treated by posterior short fixation with TIF between January 2013 to January 2017. Patients were followed up for a minimum of one and half year. For evaluation of correction loss, % loss of anterior vertebral body heights (%AVB), vertebral kyphotic angle (VA) and regional kyphotic angle (RA) were collected preoperatively, postoperatively and at final follow-up. The hardware failure was assessed on radiological images at last follow-up. Results: There were 36 patients who met the inclusion criteria with a mean follow-up duration of 53 months. The mean correction loss of %AVB, VA and, RA were 10.2%, 2.9o and 5.6o, respectively. There were 6 patients (16.7%) with hardware failure at final follow-up. Conclusions: Short-segment posterior pedicle screw fixation with TIF using bone chip graft hasn’t prevented completely the hardware failure and progressive kyphosis in treatment of unstable thoracolumbar burst fracture.

Freehand Minimally Invasive Pedicle Screw Fixation and Minimally Invasive Decompression for a Thoracic or Lumbar Vertebral Metastatic Tumor From Hepatocellular Carcinoma

Objective: To compare freehand minimally invasive pedicle screw fixation (freehand MIPS) combined with percutaneous vertebroplasty (PVP), minimally invasive decompression, and partial tumor resection with open surgery for treatment of thoracic or lumbar vertebral metastasis of hepatocellular carcinoma (HCC) with symptoms of neurologic compression, and evaluate its feasibility, efficacy, and safety.Methods: Forty-seven patients with 1-level HCC metastatic thoracolumbar tumor and neurologic symptoms were included between February 2015 and April 2017. Among them, 21 patients underwent freehand MIPS combined with PVP, minimally invasive decompression, and partial tumor resection (group 1), while 26 patients were treated with open surgery (group 2). Duration of operation, blood loss, times of fluoroscopy, incision length, and stay in hospital were compared between the two groups. Pre- and postoperative visual analog scale (VAS) pain score, Oswestry Disability Index (ODI), American Spinal Injury Association (ASIA) grade, ambulatory status, and urinary continence were also recorded. The Cobb angle and central and anterior vertebral body height were measured on lateral radiographs before surgery and during follow-ups.Results: Patients in group 1 showed significantly less blood loss (195.5 ± 169.1 ml vs. 873.1 ± 317.9 ml, P = 0.000), shorter incision length (3.4 ± 0.3 vs. 13.6 ± 1.8 cm, P = 0.000), shorter median stay in hospital (4–8/6 vs. 8–17/12 days, P = 0.000), more median times of fluoroscopy (5–11/6 vs. 4–7/5 times, P = 0.000), and longer duration of operation (204.8 ± 12.1 vs. 171.0 ± 12.0 min, P = 0.000) than group 2. Though VAS significantly decreased after surgery in both groups, VAS of group 1 was significantly lower than that of group 2 immediately after surgery and during follow-ups (P &lt; 0.05). Similar results were found in ODI. No differences in the neurological improvement and spinal stability were observed between the two groups.Conclusion: Freehand MIPS combined with PVP, minimally invasive decompression, and partial tumor resection is a safe, effective, and minimally invasive method for treating thoracolumbar metastatic tumors of HCC, with less blood loss, better pain relief, and shorter length of midline incision and stay in hospital.