BackgroundAtlantoaxial posterior pedicle screw fixation has been widely used for treatment of atlantoaxial instability (AAI). However, precise and safe insertion of atlantoaxial pedicle screws remains challenging. This study presents a modified drill guide template based on a previous template for atlantoaxial pedicle screw placement.Material/MethodsOur study included 54 patients (34 males and 20 females) with AAI. All the patients underwent posterior atlantoaxial pedicle screw fixation: 25 patients underwent surgery with the use of a modified drill guide template (template group) and 29 patients underwent surgery via the conventional method (conventional group). In the template group, a modified drill guide template was designed for each patient. The modified drill guide template and intraoperative fluoroscopy were used for surgery in the template group, while only intraoperative fluoroscopy was used in the conventional group.ResultsOf the 54 patients, 52 (96.3%) completed the follow-up for more than 12 months. The template group had significantly lower intraoperative fluoroscopy frequency (p<0.001) and higher accuracy of screw insertion (p=0.045) than the conventional group. There were no significant differences in surgical duration, intraoperative blood loss, or improvement of neurological function between the 2 groups (p>0.05).ConclusionsBased on the results of this study, it is feasible to use the modified drill guide template for atlantoaxial pedicle screw placement. Using the template can significantly lower the screw malposition rate and the frequency of intraoperative fluoroscopy.
Objective. To evaluate efficacy of platelet-rich plasma (PRP) injection in carpal tunnel syndrome (CTS), we conducted this meta-analysis, as well as proposed a protocol for its application in curative processes. Methods. All randomized controlled trials (RCTs) of PRP for the management of mild or moderate CTS were included in this study. Database search was conducted from study inception to July 2020, including PubMed, Embase, Web of Science, and Cochrane Library. We used visual analogue scores (VAS) and the Boston Carpal Tunnel Questionnaire (BCTQ) as evaluation tools for primary outcomes. Second outcomes comprised cross-sectional area (ΔCSA) and electrophysiological indexes including distal motor latency (DML), sensory peak latency (SPL), motor nerve conduction velocity (MNCV), sensory nerve conduction velocity (SNCV), compound muscle action potential (CMAP), and sensory nerve action potential (SNAP). The pooled data were analyzed using RevMan 5.3. Subgroup and sensitivity analyses were conducted with the evidence of heterogeneity. Egger’ test was used to investigate publication bias. Results. 9 RCTs were finally screened out with 434 patients included. Control groups comprised corticosteroid injection in 5 trials, saline injection in 1 trial, and splint in 3 trials. At the 1st month after follow-up, only ΔCSA between the PRP group and the control group showed significant difference (
P
<
0.05
). In the 3rd month, there were statistically significant differences in VAS, BCTQ, SPL, SNCV, and ΔCSA between two groups (
P
<
0.05
), while no statistically significant differences were found in the remaining outcomes. In the 6th month, there were statistically significant differences at BCTQ (
P
<
0.05
) in primary outcomes and ΔCSA (
P
<
0.05
) in secondary outcomes between two groups. As to adverse events in PRP injection, only one study reported increased pain sensation within 48 h after injections. Conclusion. This systematic review and meta-analysis demonstrates that the PRP could be effective for mild to moderate CTS and superior to traditional conservative treatments in improving pain and function and reducing the swelling of the median nerve for a mid-long-term effect. To some extent, the electrophysiological indexes also improved after PRP injection compared with others conservative treatments.
Introduction: Odontoid fractures easily lead to instability, causing spinal cord injury. The aim of this study was to measure and analyze the micro-architecture and morphometric parameters of the normal odontoid with highresolution three-dimensional (3D) micro-computed tomography (micro-CT). Methods: Micro-CT scans were obtained from five normal odontoid processes. The scanned data were reconstructed with micro-CT software, and the nutrient foramina and the ossification center of the base of the odontoid were revealed. The trabeculae of the odontoid were measured and divided into four parts to obtain the volume fraction of regions of interest. Results: High-resolution 3D images of the micro-structures' parameters were obtained from the odontoid using micro-CT software. The images demonstrated sponge-like trabecular bone, with the trabeculae showing a complex, net-like micro-construction. The subchondral bone plate was of lamella-like, compact construction and extended and transformed into a net-like structure with rod-shaped trabeculae arranged radially in all directions. There was a statistically significant difference in the volume fraction compared with the region of interest in the fourth part of the trabeculae and the first part of the odontoid (P < 0.05). The nutrient foramina and the ossification center of the odontoid were also observed. Conclusions: It is feasible to use high-resolution 3D micro-CT to evaluate the micro-architecture of the normal odontoid. Other studies can benefit from use of the micro-CT images, such as finite element evaluations.
BackgroundMetastases to the upper cervical spine were rarely reported in the literature. However, metastases to this area may cause spinal instability and cord compression, which in turn can result in respiratory failure and neurological dysfunction. The present study investigated the efficacy and safety of posterior decompression and occipitocervical fixation followed by intraoperative vertebroplasty for this disease.MethodsThis was a retrospective study that included 10 patients with metastatic involvement of the axis from March 2002 to May 2014. All cases presented with occipitocervical pain: 5 patients with compressive myelopathy and 6 patients with radiculopathy. Japanese Orthopedic Association (JOA) scores and Visual Analogue Scale (VAS) were used to evaluate the improvement of neurological function and pain intensity, respectively.ResultsAll patients underwent posterior decompression and occipitocervical fixation followed by intraoperative vertebroplasty. The VAS scores and JOA scores both improved postoperatively, from 8.2 ± 0.4 to 2.3 ± 0.2 and from 10.1 ± 2.2 to 14.2 ± 2.9, respectively. Additionally, the improvement rate of JOA was 52.4 ± 1.8%. The mean overall survival was 12.8 months. The median survival time was 7 months. The 6-month and 12-month survival rates were 70% and 40%, respectively. The mean duration of operation was 182 min and blood loss was 450 mL. The mean volume of bone cement injected was 4.0 mL. The cement extravasation was observed in only 1 patient without clinical symptoms. One patient developed tumour recurrence and died 1 month later.ConclusionsPosterior decompression and occipitocervical fixation followed by intraoperative vertebroplasty was a safe and valuable palliative method with relatively less invasion to treat metastatic involvement of the axis.
Under-correction of the O-C2 angle is likely to cause malalignment of the cervical spine, resulting in the development of postoperative ASD, SAS, and swan neck deformity.
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