Five-step unilateral biportal endoscopic surgery for central lumbar canal stenosis: "Z" technique nuance.

The treatment for lumbar spinal stenosis has advanced through the use of minimally invasive surgery techniques. Endoscopic methods go even further, with studies showing that both uniportal and biportal endoscopic techniques have outcomes comparable to traditional approaches. However, there is limited knowledge of the step-by-step decompression process when using the unilateral biportal endoscopic (UBE). To address this, the authors introduce the five steps in the "Z" sequence, which aims to reduce surgical time and complications. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23182.

Complications of Endoscopic Thoracic Spine Surgery: Overview and Complication Avoidance.

In endoscopic thoracic spine surgery, adaptations of thoracic surgical techniques such as full endoscopic uniportal and biportal surgical techniques have been developed. Full endoscopic uniportal surgery for thoracic disc herniation or thoracic ossified ligamentum flavum (OLF) has been performed via transforaminal and interlaminar approaches. In the case of thoracic OLF or thoracic spinal stenosis, the uniportal interlaminar approach is appropriate. The uniportal interlaminar approach has been used to treat thoracic OLF and has shown good surgical results. Thoracic OLF removal via a biportal endoscopic technique has been developed recently and is described in a few studies. Although endoscopic thoracic spine surgery has significant advantages, complications often occur with this approach. We reviewed the literature to date on the complications associated with endoscopic spine surgery in thoracic pathology. This review emphasizes how to avoid and manage complications. Based on the results of several previous studies, endoscopic thoracic spine surgery could be associated with fewer potential complications than conventional surgery. Endoscopic spine surgery has remarkable advantages; however, endoscopic thoracic surgery is technically challenging and is potentially associated with serious complications. To minimize the risk of avoidable complications, surgeons should be familiar with prevention methods and pitfalls.

Clinical outcomes of uniportal compared with biportal endoscopic decompression for the treatment of lumbar spinal stenosis: a systematic review and meta-analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVES: Lumbar spinal stenosis (LSS) treatment has evolved with the introduction of minimally invasive surgery (MIS) techniques. Endoscopic methods take the concepts applied to MIS a step further, with multiple studies showing that endoscopic techniques have outcomes that are similar to those of more traditional approaches. The aim of this study was to perform an updated meta-analysis and systematic review of studies comparing the outcomes between both available endoscopic techniques (uni and biportal) for the treatment of LSS. METHODS: Following PRISMA guidelines, we conducted a systematic literature search and compared the randomized controlled trials and retrospective studies of uniportal and biportal endoscopy in the treatment of LSS from several databases. Bias was assessed using quality assessment criteria and funnel plots. Meta-analysis using a random-effects model was used to synthesize the metadata. The authors used Review Manager 5.4 to manage the date and perform the review. RESULTS: After a preliminary selection of 388 studies from electronic databases, the full inclusion criteria were applied; three studies were found to be eligible for inclusion. There were 184 patients from three unique studies. Meta-analysis of visual analog scale score for low back pain and leg pain showed no significant difference at the final follow-up (P = 0.51 and P = 0.66). ODI score after biportal surgery was lower than uniportal surgery [SMD = 0.34, 95% CI (0.04, 0.63), P = 0.02]. The mean operation time was similar in the unilateral biportal endoscopy (UBE) and uniportal groups (P = 0.53). The UBE group was associated with a shorter length of hospital stay (P = 0.05). Complications were similar in both groups (P = 0.89). CONCLUSIONS: Current evidence shows no significant differences in most clinical outcomes between uniportal and biportal surgery. UBE may have a better ODI score at the end of the follow-up compared to uniportal. Further studies are required before drawing a definite conclusion. STUDY REGISTRATION: PROSPERO prospective register of systematic reviews: Registration Nº. CRD42022339078, Available from: https://www.crd.york.ac.uk/prospero/displayrecord.php?ID=CRD42022339078.

Unilateral Biportal Endoscopy for Decompression of Extraforaminal Stenosis at the Lumbosacral Junction: Surgical Techniques and Clinical Outcomes.

OBJECTIVE: The aims of this study were to describe the unilateral biportal endoscopic (UBE) technique for decompression of extraforaminal stenosis at L5-S1 and evaluate 1-year clinical outcomes. Especially, we evaluated compression factors of extraforaminal stenosis at L5-S1 and described the surgical technique for decompression in detail. METHODS: Thirty-five patients who underwent UBE decompression for extraforaminal stenosis at L5-S1 between March 2018 and February 2019 were enrolled. Clinical results were analyzed using the MacNab criteria, the visual analogue scale (VAS) for back and leg pain, and the Oswestry Disability Index (ODI). Compression factors evaluated pseudoarthrosis within the transverse process of L5 and ala of sacrum, disc bulging with or without osteophytes, and the thickened lumbosacral and extraforaminal ligament. RESULTS: The mean back VAS was 3.7 ± 1.8 before surgery, which dropped to 2.3 ± 0.8 at 1-year postoperative follow-up (p < 0.001). There was a significant drop in postoperative mean VAS for leg pain from 7.2 ± 1.1 to 2.3 ± 1.2 at 1 year (p < 0.001). The ODI was 61.5 before surgery and 28.6 (p < 0.001). Pseudoarthrosis between the transverse process and the ala was noted in all cases (35 of 35, 100%). Pure disc bulging was seen in 12 patients (34.3%), and disc bulging with osteophytes was demonstrated in 23 patients. The thickened lumbosacral and extraforaminal ligament were identified in 19 cases (51.4%). No complications occurred in any of the patients. CONCLUSION: In the current study, good surgical outcomes without complications were achieved after UBE decompression for extraforaminal stenosis at L5-S1.

Correction to: Clinical and radiological outcomes of unilateral biportal endoscopic lumbar interbody fusion (ULIF) compared with conventional posterior lumbar interbody fusion (PLIF): 1-year follow-up.

The original publication of this article has incorrect presentation of one of the author names. Instead of Sangu-Kyu Son, it should have been Sang-Kyu Son.

Clinical and radiological outcomes of unilateral biportal endoscopic lumbar interbody fusion (ULIF) compared with conventional posterior lumbar interbody fusion (PLIF): 1-year follow-up.

This study retrospectively compared clinical and radiological outcomes of unilateral biportal endoscopic lumbar interbody fusion (ULIF) to those of conventional posterior lumbar interbody fusion (PLIF). Seventy-one ULIF (age, 68 ± 8 years) and 70 PLIF (66 ± 9 years) patients for one lumbosacral segment followed more than 1 year were selected. Parameters for surgical techniques (operation time, whether transfused), clinical results [visual analogue scale (VAS) for back and leg pain, Oswestry disability index (ODI)], surgical complications (dural tear, nerve root injury, infection), and radiological results (cage subsidence, screw loosening, fusion) between the two groups were compared. The PLIF group demonstrated a significantly shorter operation time and more transfusions done than the ULIF group. The VAS for leg pain in both groups and for back pain in the ULIF group significantly improved at 1 week, while the VAS for back pain in the PLIF group significantly improved at 1 year. ODI scores improved at 1 year in both groups. Complication rates were not significantly different between groups. Fusion rates with definite and probable grades were not significantly different between groups. However, the ULIF group had significantly (P = 0.013) fewer cases of definite fusion and more cases of probable fusion [43 (74.1%) and 15 (25.9%) cases, respectively] than the PLIF group [58 (92.1%) and 5 (7.9%) cases, respectively]. ULIF is less invasive while just as effective as conventional PLIF in improving clinical outcomes and obtaining fusion. However, ULIF has a longer operation time than PLIF and requires further development to improve the fusion grade.

Risk factors for cage migration and cage retropulsion following transforaminal lumbar interbody fusion.

BACKGROUND CONTEXT: Transforaminal lumbar interbody fusion (TLIF) is a widely accepted surgical procedure, but cage migration (CM) and cage retropulsion (CR) are associated with poor outcomes. PURPOSE: This study seeks to identify risk factors associated with these serious events. STUDY DESIGN: A prospective observational longitudinal study. PATIENT SAMPLE: Over a 5-year period, 881 lumbar levels in 784 patients were treated using TLIF at three spinal surgery centers. OUTCOME MEASURES: We evaluated the odds ratio of the risk factors for CM with and without subsidence and CR in multivariate analysis. METHODS: Our study classified CM into two subgroups: CM without subsidence and CM with subsidence. Cases of spinal canal and/or foramen intrusion of the cage was defined separately as CR. Patient records, operative notes, and radiographs were analyzed for factors potentially related to CM with subsidence, CM without subsidence, and CR. RESULTS: Of 881 lumbar levels treated with TLIFs, CM without subsidence was observed in 20 (2.3%) and CM with subsidence was observed in 36 (4.1%) patients. Among the CM cases, CR was observed in 17 (17/56, 30.4%). The risk factors of CM without subsidence were osteoporosis (OR 8.73, p < .001) and use of a unilateral single cage (OR 3.57, p < .001). Osteoporosis (OR 5.77, p < .001) and endplate injury (OR 26.87, p < .001) were found to be significant risk factors for CM with subsidence. Risk factors of CR were osteoporosis (OR 7.86, p < .001), pear-shaped disc (OR 8.28, p = .001), endplate injury (OR 18.70, p < .001), unilateral single cage use (OR 4.40, p = .03), and posterior cage position (OR 6.45, p = .04). A difference in overall fusion rates was identified, with a rate of 97.1% (801 of 825) for no CM, 55.0% (11 of 20) for CM without subsidence, 41.7% (15 of 36) for CM with subsidence, and 17.6% (3 of 17) for CR at 1.5 years postoperatively. CONCLUSIONS: Our results suggest that osteoporosis is a significant risk factor for both CM and CR. In addition, a pear-shaped disc, posterior positioning of the cage, the presence of endplate injury and the use of a single cage were correlated with the CM with and without subsidence and CR.

Analysis of Computed Tomography Scan After Anterior Odontoid Screw Fixation with the Herbert Screw: Is It Effective to Reduce Fracture Gap?

OBJECTIVE: To assess computed tomography scans to evaluate the extent of reduction of fracture displacement and fracture gap after anterior odontoid screw fixation using the Herbert screw. METHODS: Thirty-seven odontoid fractures were reduced and treated by anterior odontoid screw fixation with the Herbert screw. There were 37 patients whose age ranged from 20 to 79 years. Three-dimensional computed tomography scans were obtained for all patients to assess the screw position, the presence of the penetration of superior cortex of dens, the extent of reduction of fracture displacement, and fracture gap. RESULTS: Mean fracture displacement was 2.6 ± 3.2 mm before surgery; after the operation this value was 1.0 ± 1.5 mm. The difference in fracture gap between the preoperative and the postoperative state was -0.1 ± 1.1 mm, which was not statistically significant (P = 0.667). We achieved cortical purchase in only 16 of 37 patients (43.2%); cortical purchase was not obtained in 21 patients (56.7%) due to the fear of the risk of the damage of neural and vascular structures. Of these 21 patients who had no penetration of the superior cortex of dens, widening of the fracture gap occurred in 12 patients (57%), no change in 6 patients (29%), and there was shortening in 3 patients (14%). However, of the 16 patients with penetration of apical dens tip, we achieved significant reduction of fracture gap (P = 0.002). CONCLUSIONS: To maximize reduction of fracture gap using the Herbert screw, it is essential to penetrate the apical dens tip.

Recurrent esophageal perforation after anterior cervical spine surgery: case report.

PURPOSE: Delayed esophageal perforation after anterior cervical discectomy and fusion (ACDF) is an extremely rare cause of infection such as spondylodiscitis. We present a rare case in which a patient had two delayed esophageal perforations occurring 20 and 25 years after ACDF. By sharing our experience of this rare case, we hope to provide new information related to delayed esophageal perforation. METHODS: We present the case of a 72-year-old patient who underwent ACDF due to cervical spondylosis 25 years ago. Delayed esophageal perforation occurred 20 years postoperatively and healed spontaneously with conservative treatment. RESULTS: Five years later, a second esophageal perforation occurred, which required surgical intervention and involved recurrent infection. CONCLUSIONS: We suggest that it is important to consider follow-up in patients with spontaneously healed esophageal perforations. Furthermore, any patient with symptoms subsequent to a spontaneously healed esophageal perforation, even after an interval of several years, should receive a thorough evaluation for possible recurrent esophageal perforation.

Relationships between vitamin D and paraspinal muscle: human data and experimental rat model analysis.

BACKGROUND CONTEXT: Vitamin D deficiency (VDD) has been closely linked with skeletal muscle atrophy in many studies, but to date no study has focused on the paraspinal muscle. PURPOSE: To verify paraspinal muscle changes according to serum vitamin D level. STUDY DESIGN: A cross-sectional study of patients who visited our hospital and an in vivo animal study. METHODS: We measured serum vitamin D concentration in 91 elderly women and stratified them according to their vitamin D status in three groups, control, vitamin D insufficiency, and VDD, and obtained magnetic resonance imaging data of the lumbar spine and evaluated the quality and quantity of the paraspinal muscles. Additionally, we designed experimental rat models for VDD and VDD replacement. Then, we analyzed the microcomputed tomography data and histologic data of paraspinal muscles, and the histologic data and reverse transcription-quantitative polymerase chain reaction data of intramyonuclear vitamin D receptor (VDR) in paraspinal muscle through comparison with control rats (n=25, each group). This work was supported by a Biomedical Research Institute grant ($40,000), Kyungpook National University Hospital (2014). RESULTS: In the human studies, a significant decrease was noted in the overall paraspinal muscularity (p<.05) and increase in fatty infiltration in the VDD group as compared with the other groups (p<.05). In the rat experiment, a decrease was noted in paraspinal muscle fiber size and VDR concentration and VDR gene expression level, and total muscle volume of the VDD rats as compared with the control rats (p<.05). Vitamin D replacement after VDD could partially restore the muscle volume, muscle fiber size, and intramyonuclear VDR concentration levels (p<.05) of the paraspinal muscles. CONCLUSIONS: VDD induces paraspinal muscle atrophy and decreases the intramyonuclear VDR concentration and VDR gene expression level in these muscles. Vitamin D replacement contributes to the recovery from atrophy and restoration of intramyonuclear VDR concentration in VDD status.

Myelopathy associated with instability consequent to resection of ossification of anterior longitudinal ligament in DISH.

PURPOSE: The presence of prominent OALL (ossification of anterior longitudinal ligament) in the anterior cervical spine has been implicated as a cause of dysphagia. Surgical resection of the OALL is considered effective for the management of diffuse idiopathic skeletal hyperostosis (DISH)-related dysphagia. Although many reports have been published on DISH-related dysphagia, no cases of postoperative cervical instability have been reported thus far. We present a case in which the patient developed myelopathy associated with instability consequent to resection of OALL in DISH. METHODS: A 62-year-old man presented with progressive dysphagia that persisted for a year. The patient's symptoms were successfully resolved by resection of OALL. Five years after the surgery, the dysphagia resurfaced and was found to be caused by the regrowth of the OALL. A repeat surgery was performed, and the dysphagia disappeared. Eleven months after the second surgery, he visited the hospital with progressive quadriparesis and pain in the cervical region. RESULTS: Nine-month follow-up radiologic study revealed cervical instability at the level of C5-6 resulting in myelopathy. The patient underwent decompressive laminectomy and posterior fusion surgery. CONCLUSION: Surgical resection of DISH-related dysphagia typically yields excellent outcomes, but our experience in this case highlights the possibility of OALL regrowth and subsequent cervical instability after resection of OALL.

A Retrospective Analysis of Ventriculoperitoneal Shunt Revision Cases of a Single Institute.

OBJECTIVE: Ventriculoperitoneal (VP) shunt complication is a major obstacle in the management of hydrocephalus. To study the differences of VP shunt complications between children and adults, we analyzed shunt revision surgery performed at our hospital during the past 10 years. METHODS: Patients who had undergone shunt revision surgery from January 2001 to December 2010 were evaluated retrospectively by chart review about age distribution, etiology of hydrocephalus, and causes of revision. Patients were grouped into below and above 20 years old. RESULTS: Among 528 cases of VP shunt surgery performed in our hospital over 10 years, 146 (27.7%) were revision surgery. Infection and obstruction were the most common causes of revision. Fifty-one patients were operated on within 1 month after original VP shunt surgery. Thirty-six of 46 infection cases were operated before 6 months after the initial VP shunt. Incidence of shunt catheter fracture was higher in younger patients compared to older. Two of 8 fractured catheters in the younger group were due to calcification and degradation of shunt catheters with fibrous adhesion to surrounding tissue. CONCLUSION: The complications of VP shunts were different between children and adults. The incidence of shunt catheter fracture was higher in younger patients. Degradation of shunt catheter associated with surrounding tissue calcification could be one of the reasons of the difference in facture rates.

Surgical Tips to Preserve the Facet Joint during Microdiscectomy.

Lumbar microdiscectomy (MD) is the gold standard for treatment of lumbar disc herniation. Generally, the surgeon attempts to protect the facet joint in hopes of avoiding postoperative pain/instability and secondary degenerative arthropathy. We believe that preserving the facet joint is especially important in young patients, owing to their life expectancy and activity. However, preserving the facet joint is not easy during lumbar MD. We propose several technical tips (superolateral extension of conventional laminotomy, oblique drilling for laminotomy, and additional foraminotomy) for facet joint preservation during lumbar MD.

Malignant peripheral nerve sheath tumor of non-neurofibromatosis type I metastasized to the cerebrospinal axis.

A malignant peripheral nerve sheath tumor (MPNST) is a type of sarcoma that arises from peripheral nerves or cells of the associated nerve sheath. This tumor most commonly metastasizes to the lung and metastases to the spinal cord and brain are very rare. We describe a case of young patient with spinal cord and brain metastases resulting from MPNST. An 18-year-old man presented with a 6-month history of low back pain and radiating pain to his anterior thigh. Magnetic resonance imaging showed a paraspinal mass that extended from the central space of L2 to right psoas muscle through the right L2-3 foraminal space. The patient underwent surgery and the result of the histopathologic study was diagnostic for MPNST. Six months after surgery, follow-up images revealed multiple spinal cord and brain metastases. The patient was managed with chemotherapy, but died several months later. Despite complete surgical excision, the MPNST progressed rapidly and aggressively. Thus, patients with MPNST should be followed carefully to identify local recurrence or metastasis as early as possible.