A prospective clinical study of a multistep screw insertion method using a patient-specific screw guide template system (SGTS) for the cervical and thoracic spine.
To evaluate the efficacy of SGTS ...for inserting screws into the cervical and thoracic spine.
Posterior screw fixation is a standard procedure for spinal instrumentation; however, screw insertion carries the risk of injury to neuronal and vascular structures.
Preoperative bone images of the computed tomography (CT) scans were analyzed using 3D/multiplanar imaging software, and the screw trajectories were planned. Plastic templates with screw-guiding structures were created for each lamina using 3D design and printing technology. Three types of templates were made for precise multistep guidance, and all the templates were specially designed to fit and lock onto the lamina during the procedure. In addition, plastic vertebra models were generated, and preoperative screw insertion simulation was performed. This patient-specific SGTS was used to perform the surgery, and CT scanning was used to postoperatively evaluate screw placement.
Enrolled to verify this procedure were 103 patients with cervical, thoracic, or cervicothoracic pathologies. The SGTS were used to place 813 screws. Preoperatively, each template was found to fit exactly and to lock onto the lamina of the vertebra models. In addition, intraoperatively, the templates fit and locked onto the patient lamina, and the screws were inserted successfully. Postoperative CT scans confirmed that 801 screws (98.5%) were accurately placed without cortical violation. There were no injuries to the vessels or nerves.
The multistep, patient-specific SGTS is useful for intraoperative pedicle screw (PS) navigation in the cervical and thoracic spine. This method improves the accuracy of PS insertion and reduces the operating time and radiation exposure during spinal fixation surgery.
3.
Objectives. Failed back surgery syndrome (FBSS) refers to a condition where symptoms such as low back pain, leg pain, and numbness persist or recur after lumbar surgery; it has been reported to occur ...in 10%–40% of patients who have undergone lumbar surgery. Spinal cord stimulation (SCS) has been reported useful for low back and leg pain due to FBSS. In this study, we studied the efficacy and safety of SCS for FBSS in older adults. Methods. Among FBSS patients who underwent an SCS trial between November 2017 and December 2020, those with at least 50% pain reduction during the trial phase who requested spinal cord stimulator implantation underwent implantation of a stimulator under local anesthesia. The patients were divided into two groups: patients aged <75 years (<75-year-old group) and patients aged ≥75 years (≥75-year-old group). The male/female ratio, symptom duration, operative duration, visual analog scale (VAS) scores before and after one year of surgery, responder rate (RR), complications one year after surgery, and stimulator removal rate were analyzed. Results. There were 27 cases in the <75-year-old group and 46 in the ≥75-year-old group, with no significant differences in male/female ratio, duration of pain, or operative time between the two groups. VAS scores for low back pain, leg pain, and overall pain one year after surgery were improved significantly from respective preoperative scores in both groups P<0.001. There were no significant differences in low back pain VAS, leg pain VAS, overall pain VAS, RR, complications one year after surgery, or stimulator removal rate between the two groups. Conclusion. SCS reduced pain effectively in both <75-year-old and ≥75-year-old groups with no differences in complications. Therefore, spinal cord stimulator implantation was considered a viable option for FBSS treatment in older adults because it can be performed under local anesthesia and is associated with a low incidence of complications.
Persistent first intersegmental artery (PFIA) is a rare anatomical variation of vertebral arteries and is an asymptomatic finding in most cases. Here we report a rare case of cervical myelopathy ...caused by spinal cord compression by the PFIA.
The patient was a 52-year-old man who complained of numbness and burning sensation around the neck and left shoulder area, partial weakness in the left deltoid muscle, right side thermal hypoalgesia, and disturbance of deep sensation since the past 1 year, and the symptoms had gradually worsened. Magnetic resonance imaging (MRI) and computed tomography (CT) showed spinal cord compression by the left PFIA at the C1/C2 level. Because conservative treatment was ineffective, microvascular decompression (MVD) of the PFIA was performed. The left PFIA was laterally transposed using polytetrafluoroethylene (PTFE) bands and anchored to the dura mater using three PTFE bands. To achieve adequate transposition, the small blood vessels bridging the spinal cord and PFIA and the dorsal root nerve had to be sacrificed. Postoperative T2-weighted MRI showed a small hyperintense region in the lateral funiculus of the spinal cord, but no new neurological deficits were identified. In the early postoperative stage, the patient's deep sensory impairment and motor dysfunction were improved. His numbness and burning sensation almost disappeared, but slight thermal hypoalgesia remained in the lower limb.
MVD is an effective treatment for spinal cord compression caused by the PFIA, but further studies are necessary to help address technical difficulties and avoid complications.
A 67-year-old man presented with a 2-month history of pain in his right buttock and lower limb. MRI depicted right L5/S1 lateral recess stenosis requiring surgical treatment; however, preoperative CT ...showed an approximately 7 cm long, thin, rod-shaped structure in the rectum, which was ultimately determined to be an accidentally ingested toothpick. It was removed surgically 6 days after diagnosis, because right leg pain worsened rapidly. The pain disappeared thereafter, and the symptoms have not recurred since. The pain might have been localised to the right buttock and posterior thigh in the early stages because the fine tip of the toothpick was positioned to the right of the anterior ramus of the S2 spinal nerve. Although sacral plexus disorder caused by a rectal foreign body is extremely rare, physicians should be mindful to avoid misdiagnosis.
Myelopathy symptoms were prospectively studied in patients with cervical spinal canal stenosis (CSCS), using objective grading systems and stabilometry, to examine the effect of administration of ...prostaglandin E1 derivative limaprost alfadex (limaprost).
Myelopathy scores/grades and stabilometry parameters were evaluated before, and 1 and 3 months after starting the limaprost treatment.
Limaprost is a potent vasodilator and antiplatelet agent and has been used to treat the symptoms of lumbar spinal canal stenosis. The action presumably involves increased blood flow in the compressed cauda equina. Limaprost can also increase blood flow in the compressed spinal cord, but effects on myelopathy symptoms in patients with CSCS have not been established.
This study examined 21 patients with mild spondylotic CSCS based on neurologic findings and compression of the cervical spinal cord on magnetic resonance imaging. Japanese Orthopedic Association score, grip and release test, and finger escape sign were measured, and stabilometry was performed by independent examiners, before, and 1 and 3 months after starting the oral limaprost treatment.
Most patients experienced amelioration of the symptoms at 1 month after starting the treatment. Mean Japanese Orthopedic Association score and grip and release count were significantly improved and finger escape sign grade was higher in some patients. Stabilometry area with eyes closed and Romberg rate were also significantly improved. These improvements were maintained at 3 months.
The efficacy of oral limaprost administration for patients with CSCS was confirmed by objective scoring and quantitative data.
Prospective clinical trial of the screw insertion method for posterior C1-C2 fixation utilizing the patient-specific screw guide template technique.
To evaluate the efficacy of this method for ...insertion of C1 lateral mass screws (LMS), C2 pedicle screws (PS), and C2 laminar screws (LS).
Posterior C1LMS and C2PS fixation, also known as the Goel-Harms method, can achieve immediate rigid fixation and high fusion rate, but the screw insertion carries the risk of injury to neuronal and vascular structures. Dissection of venous plexus and C2 nerve root to confirm the insertion point of the C1LMS may also cause problems. We have developed an intraoperative screw guiding method using patient-specific laminar templates.
Preoperative bone images of computed tomography (CT) were analyzed using three-dimensional (3D)/multiplanar imaging software to plan the trajectories of the screws. Plastic templates with screw guiding structures were created for each lamina using 3D design and printing technology. Three types of templates were made for precise multistep guidance, and all templates were specially designed to fit and lock on the lamina during the procedure. Surgery was performed using this patient-specific screw guide template system, and placement of the screws was postoperatively evaluated using CT.
Twelve patients with C1-C2 instability were treated with a total of 48 screws (24 C1LMS, 20 C2PS, 4 C2LS). Intraoperatively, each template was found to exactly fit and lock on the lamina and screw insertion was completed successfully without dissection of the venous plexus and C2 nerve root. Postoperative CT showed no cortical violation by the screws, and mean deviation of the screws from the planned trajectories was 0.70 ± 0.42 mm.
The multistep, patient-specific screw guide template system is useful for intraoperative screw navigation in posterior C1-C2 fixation. This simple and economical method can improve the accuracy of screw insertion, and reduce operation time and radiation exposure of posterior C1-C2 fixation surgery.
3.
Extradural or subcutaneous cerebrospinal fluid (CSF) leakage is a common complication after spinal surgery and is associated with the risks of poor wound healing, meningitis, and pseudomeningocele. ...Numerous methods to prevent postoperative CSF leakage are available, but pressure-tight dural closure remains difficult, especially with synthetic surgical membranes. The efficacy of a novel dural closure technique was assessed by detecting extradural or subcutaneous CSF leakage on magnetic resonance imaging.
The novel dural closure technique using absorbable polyglactin acid sheet and fibrin glue and the conventional procedure using only fibrin glue were evaluated retrospectively by identifying extradural or subcutaneous CSF leakage on magnetic resonance imaging scans in the acute (2-7 d) and chronic (3-6 mo) postoperative stages after spinal intradural surgery in 53 patients.
The incidence of extradural and subcutaneous CSF leakage was significantly lower (P < 0.05) in the acute (20%) and chronic (0%) stages using polyglactin acid sheet and fibrin glue in 15 patients compared with that in the acute (81%) and chronic (24%) stages using only fibrin glue in 38 patients. One patient in the fibrin glue-only group required repair surgery for cutaneous CSF leakage.
The combination of polyglactin acid sheet and fibrin glue can achieve water-tight closure after spinal intradural surgery and can minimize the risk of intractable postoperative CSF leakage. This simple, economical technique is recommended for dural closure after spinal intradural surgery.
Accurate insertion of C-2 cervical screws is imperative; however, the procedures for C-2 screw insertion are technically demanding and challenging, especially in cases of C-2 vertebral abnormality. ...The purpose of this study is to report the effectiveness of the tailor-made screw guide template (SGT) system for placement of C-2 screws, including in cases with abnormalities.
Twenty-three patients who underwent posterior spinal fusion surgery with C-2 cervical screw insertion using the SGT system were included. The preoperative bone image on CT was analyzed using multiplanar imaging software. The trajectory and depth of the screws were designed based on these images, and transparent templates with screw guiding cylinders were created for each lamina. During the operation, after templates were engaged directly to the laminae, drilling, tapping, and screwing were performed through the templates. The authors placed 26 pedicle screws, 12 pars screws, 6 laminar screws, and 4 C1-2 transarticular screws using the SGT system. To assess the accuracy of the screw track under this system, the deviation of the screw axis from the preplanned trajectory was evaluated on postoperative CT and was classified as follows: Class 1 (accurate), a screw axis deviation less than 2 mm from the planned trajectory; Class 2 (inaccurate), 2 mm or more but less than 4 mm; and Class 3 (deviated), 4 mm or more. In addition, to assess the safety of the screw insertion, malpositioning of the screws was also evaluated using the following grading system: Grade 0 (containing), a screw is completely within the wall of the bone structure; Grade 1 (exposure), a screw perforates the wall of the bone structure but more than 50% of the screw diameter remains within the bone; Grade 2 (perforation), a screw perforates the bone structures and more than 50% of the screw diameter is outside the pedicle; and Grade 3 (penetration), a screw perforates completely outside the bone structure.
In total, 47 (97.9%) of 48 screws were classified into Class 1 and Grade 0, whereas 1 laminar screw was classified as Class 3 and Grade 2. Mean screw deviations were 0.36 mm in the axial plane (range 0.0-3.8 mm) and 0.30 mm in the sagittal plane (range 0.0-0.8 mm).
This study demonstrates that the SGT system provided extremely accurate C-2 cervical screw insertion without configuration of reference points, high-dose radiation from intraoperative 3D navigation, or any registration or probing error evoked by changes in spinal alignment during surgery. A multistep screw placement technique and reliable screw guide cylinders were the key to accurate screw placement using the SGT system.
Retrospective consecutive cohort study.
To study the effectiveness of β-tricalcium phosphate (β-TCP) granules as a packing material in the titanium cages for anterior cervical discectomy and fusion ...(ACDF), compared with the conventional hydroxyapatite (HA) granules.
ACDF using titanium cages is a standard procedure for the treatment of cervical spinal degenerative diseases. Synthetic bone substitutes are widely used to pack the titanium cage to augment intervertebral bony fusion, but the efficacy has not been confirmed.
Fusion condition was evaluated on lateral radiographs and computed tomography. Complete fusion of the treated segments was defined by three criteria: movement of the spinous process at flexion and extension positions of less than 3 mm, bony bridging between vertebral bodies, and absence of the halo around the titanium cage. The evaluation was performed at 6 months, 1 year, and 2 years after surgery.
Intervertebral fusion was studied in patients who underwent ACDF using β-TCP (93 segments of 57 patients) or HA (72 segments of 48 patients) packing of cylindrical titanium cages. Complete fusion rate at 6 months and 1 year was significantly better in the β-TCP group (46% at 6 months and 69% at 1 year) than in the HA group (24% at 6 months and 49% at 1 year), but the rate was similar at 2 years in the β-TCP group (94%) and the HA group (90%). There were no material-related adverse effects.
Satisfactory final fusion rates were obtained after ACDF using both β-TCP- and HA-packed titanium cages. β-TCP showed higher fusion rate in the early stage after surgery and can be recommended as a bone substitute for ACDF with titanium cages.
PDF
