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OBJECTIVEPersistent lumbar foraminal stenosis (LFS) is one of the most common reasons for poor postoperative outcomes and is a major contributor to “failed back surgery syndrome.” The authors describe a new surgical strategy for LFS based on anatomical considerations using 3D image fusion with MRI/CT analysis.METHODSA retrospective review was conducted on 78 consecutive patients surgically treated for LFS at the lumbosacral junction (2013–2017). The location and extent of stenosis, including the narrowest site and associated pathology (bone or soft tissue), were measured using 3D image fusion with MRI/CT. Stenosis was defined as medial intervertebral foraminal (MF; inner edge to pedicle center), lateral intervertebral foraminal (LF; pedicle center to outer edge), or extraforaminal (EF; outside the pedicle). Lumbar (low-back pain, leg pain) and patient satisfaction visual analog scale (VAS) scores and Japanese Orthopaedic Association (JOA) scores were evaluated. Surgical outcome was evaluated 2 years postoperatively.RESULTSMost instances of stenosis existed outside the pedicle’s center (94%), including LF (58%), EF (36%), and MF (6%). In all MF cases, stenosis resulted from soft-tissue structures. The narrowest stenosis sites were localized around the pedicle’s outer border. The areas for sufficient nerve decompression were extended in MF+LF (10%), MF+LF+EF (14%), LF+EF (39%), LF (11%), and EF (26%). No iatrogenic pars interarticularis damage occurred. The JOA score was 14.9 ± 2.6 points preoperatively and 22.4 ± 3.5 points at 2 years postoperatively. The JOA recovery rate was 56.0% ± 18.6%. The VAS score (low-back and leg pain) was significantly improved 2 years postoperatively (p < 0.01). According to patients’ self-assessment of the minimally invasive surgery, 62 (79.5%) chose “surgery met my expectations” at follow-up. Nine patients (11.5%) selected “I did not improve as much as I had hoped but I would undergo the same surgery for the same outcome.”CONCLUSIONSMost LFS existed outside the pedicle’s center and was rarely noted in the pars region. The main regions of stenosis were localized to the pedicle’s outer edge. Considering this anatomical distribution of LFS, the authors recommend that lateral fenestration should be the first priority for foraminal decompression. Other surgical options including foraminotomy, total facetectomy, and hemilaminectomy likely require more bone resections than LFS treatment. The microendoscopic surgery results were very good, indicating that this minimally invasive surgery was suitable for treating this disease.

In diffuse idiopathic hyperostosis (DISH), the ankylosed spine becomes susceptible to spinal fractures and spinal cord injuries due to the long lever arms of the fractured segments that make the fracture extremely unstable. The aim of this retrospective multicenter study was to examine the differences in DISH-affected spine fractures according to fracture level. The data of 285 cases with fractures of DISH-ankylosed segments diagnosed through computed tomography (CT) imaging were studied and the characteristics of 84 cases with cervical fractures were compared to 201 cases with thoracolumbar fractures. Examination of the CT images revealed that cervical fracture cases were associated with ossification of the posterior longitudinal ligament and had fractures at the intervertebral disc level, while thoracolumbar fracture cases were associated with ankylosing of the posterior elements and had fractures at the vertebral body. Neurologically, cervical fracture cases had a higher ratio of spinal cord injury leading to higher mortality, while thoracolumbar fracture cases had lower rates of initial spinal cord injury. However, a subset of thoracolumbar fracture cases suffered from a delay in diagnosis that led to higher rates of delayed neurological deterioration. Some of these thoracolumbar fracture cases had no apparent injury episode but experienced severe neurological deterioration. The information provided by this study will hopefully aid in the education of patients with DISH and raise the awareness of clinicians to potential pitfalls in the assessment of DISH trauma patients.

Study Design: Retrospective cohort study. Objectives: To investigate the effectiveness and safety of a gelatin–thrombin matrix sealant (GTMS) during microendoscopic laminectomy (MEL) for lumbar spinal canal stenosis (LSCS). Methods: This study included 158 LSCS cases on hemostasis-affecting medication who underwent MEL by a single surgeon between September 2016 and August 2020. Patients were divided into 2 groups depending on whether GTMS was used (37 cases, Group A) or not (121 cases, Group B). Perioperative data related to bleeding or postoperative spinal epidural hematoma (PSEH) was investigated. Clinical outcomes were evaluated using the Japanese Orthopedic Association (JOA) score for low back pain. Results: The mean intraoperative blood loss per level was greater in Group A (26.0 ± 20.3 g) than in Group B (13.6 ± 9.0 g), whereas the postoperative drainage volume was smaller in Group A (79.1 ± 42.5 g) than in Group B (97.3 ± 55.6 g). No revision surgeries for PSEH were required in Group A, while 2 (1.7%) revisions were required in Group B ( P = .957). The median JOA score improved significantly from the preoperative period to 1-year postoperatively in both Group A and B (total score, 16.0-23.5 and 17.0-25.0 points, respectively). Conclusions: The use of GTMS during MEL for LSCS may be associated with a reduction in postoperative drainage volume. The revision rate for PSEH was not affected significantly by the use of GTMS. Clinical outcomes (represented by the JOA score) were significantly improved after the surgery, regardless of GTMS use during MEL.

OBJECTIVEVarious surgical treatments have been reported for vertebral pseudarthrosis after osteoporotic vertebral fracture (OVF). However, the outcomes are not always good. The authors now have some experience with combined anterior-posterior short-segment spinal fusion (1 level above and 1 level below the fracture) using a wide-foot-plate expandable cage. Here, they report their surgical outcomes with this procedure.METHODSBetween June 2016 and August 2018, 16 consecutive patients (4 male and 12 female; mean age 75.1 years) underwent short-segment spinal fusion for vertebral pseudarthrosis or delayed collapse after OVF. The mean observation period was 20.1 months. The level of the fractured vertebra was T12 in 4 patients, L1 in 3, L2 in 4, L3 in 3, and L4 in 2. Clinical outcomes were assessed using the lumbar Japanese Orthopaedic Association (JOA) scale and 100-mm visual analog scale for low-back pain. Local kyphotic angle, intervertebral height, bone union rate, and instrumentation-related adverse events were investigated as imaging outcomes. The data were analyzed using the Wilcoxon signed-rank test.RESULTSThe mean operating time was 334.3 minutes (range 256–517 minutes), and the mean blood loss was 424.9 ml (range 30–1320 ml). The only perioperative complication was a superficial infection of the posterior wound that was cured by irrigation. The lumbar JOA score and visual analog scale value improved from 11.2 and 58.8 mm preoperatively to 20.6 and 18.6 mm postoperatively, respectively. The mean local kyphotic angle and mean intervertebral height were 22.6° and 28.0 mm, respectively, before surgery, −1.5° and 40.5 mm immediately after surgery, and 7.0° and 37.1 mm at the final observation. Significant improvement was observed in both parameters immediately after surgery and at the final observation when compared with the preoperative values. Intraoperative endplate injury occurred in 8 cases, and progression of cage subsidence of 5 mm or more was observed in 2 of these cases. Proximal junctional kyphosis was observed in 2 cases. There were no cases of screw loosening. No cases required reoperation due to instrument-related adverse events. Bone union was observed in all 14 cases that had CT evaluation.CONCLUSIONSThis short-segment fusion procedure is relatively minimally invasive, and local reconstruction and bone fusion have been achieved. This procedure is considered to be attempted for the surgical treatment of osteoporotic vertebral pseudarthrosis after OVF.