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.

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.

Preoperative Risk Factors for Recurrent Lumbar Disk Herniation in L5-S1.

BACKGROUND CONTEXT: Although numerous studies have reported on recurrent lumbar disk herniation (rLDH), few have reported on recurrence of L5-S1 level. PURPOSE: We investigated whether the preoperative risk factors, such as disk degeneration, disk height, sagittal range of motion (sROM), width of L5 vertebral transverse process, and iliac crest height, have any effect on rLDH in L5-S1. STUDY DESIGN: A retrospective case control study. PATIENT SAMPLE: A total of 467 patients were enrolled in this study. OUTCOME MEASURES: The disk degeneration, disk height, sROM, width of L5 vertebral transverse process, and iliac crest height were calculated using magnetic resonance imaging and simple radiography. MATERIALS AND METHODS: We compared the clinical parameters (age, sex, body mass index, symptom duration, diabetes, smoking, preoperative visual analogue scale, herniation type, annular defect size) and preoperative radiologic parameters [disk degeneration, disk height, sROM, relative width of L5 vertebral transverse process (RT), iliac crest height index (IHI)] of recurrent and nonrecurrent groups. RESULTS: Patient with rLDH had its onset 39.4±17.9 months (7-90 mo) after primary surgery. Of the 39 rLDH cases, herniation was ipsilateral to previous LDH in 29 patients and contralateral in 10. Multiple logistic regression analysis showed that moderate disk degeneration with preserved height (group B), a large sROM, a small RT, a low IHI, and being male were significant risk factors for rLDH. CONCLUSIONS: Moderate disk degeneration, a large sROM, a small RT, and a low IHI are biomechanical risk factors of rLDH in L5-S1. The results also suggested being male and having a large annular defect increase recurrence after discectomy, especially in cases of ipsilateral rLDH.

Navigation-Guided/Robot-Assisted Spinal Surgery: A Review Article.

The development of minimally invasive spinal surgery utilizing navigation and robotics has significantly improved the feasibility, accuracy, and efficiency of this surgery. In particular, these methods provide improved accuracy of pedicle screw placement, reduced radiation exposure, and shortened learning curves for surgeons. However, research on the clinical outcomes and cost-effectiveness of navigation and robot-assisted spinal surgery is still in its infancy. Therefore, there is limited available evidence and this makes it difficult to draw definitive conclusions regarding the long-term benefits of these technologies. In this review article, we provide a summary of the current navigation and robotic spinal surgery systems. We concluded that despite the progress that has been made in recent years, and the clear advantages these methods can provide in terms of clinical outcomes and shortened learning curves, cost-effectiveness remains an issue. Therefore, future studies are required to consider training costs, variable initial expenses, maintenance and service fees, and operating costs of these advanced platforms so that they are feasible for implementation in standard clinical practice.

Electrical stimulation promotes functional recovery after spinal cord injury by activating endogenous spinal cord-derived neural stem/progenitor cell: an in vitro and in vivo study.

BACKGROUND CONTEXT: Electrical stimulation is a noninvasive treatment method that has gained popularity in the treatment of spinal cord injury (SCI). Activation of spinal cord-derived neural stem/progenitor cell (SC-NSPC) proliferation and differentiation in the injured spinal cord may elicit considerable neural regenerative effects. PURPOSE: This study aimed to explore the effect of electrical stimulation on the neurogenesis of SC-NSPCs. STUDY DESIGN: This study analyzed the effects of electrical stimulation on neurogenesis in rodent SC-NSPCs in vitro and in vivo and evaluated functional recovery and neural circuitry improvements with electrical stimulation using a rodent SCI model. METHODS: Rats (20 rats/group) were assigned to sham (Group 1), SCI only (Group 2), SCI + electrode implant without stimulation (Group 3), and SCI + electrode with stimulation (Group 4) groups to count total SC-NSPCs and differentiated neurons and to evaluate morphological changes in differentiated neurons. Furthermore, the Basso, Beattie, and Bresnahan scores were analyzed, and the motor- and somatosensory-evoked potentials in all rats were monitored. RESULTS: Biphasic electrical currents enhanced SC-NSPC proliferation differentiation and caused qualitative morphological changes in differentiated neurons in vitro. Electrical stimulation promoted SC-NSPC proliferation and neuronal differentiation and improved functional outcomes and neural circuitry in SCI models. Increased Wnt3, Wnt7, and ß-catenin protein levels were also observed after electrical stimulation. CONCLUSIONS: Our study proved the beneficial effects of electrical stimulation on SCI. The Wnt/ß-catenin pathway activation may be associated with this relationship between electrical stimulation and neuronal regeneration after SCI. CLINICAL SIGNIFICANCE: The study confirmed the benefits of electrical stimulation on SCI based on cellular, functional, electrophysiological, and histological evidence. Based on these findings, we expect electrical stimulation to make a positive and significant difference in SCI treatment strategies.

Intramedullary spinal cord metastasis in renal cell carcinoma: a case report of the surgical experience.

Intramedullary spinal cord metastasis (ISCM) from renal cell carcinoma (RCC) is rare manifestation and most of them are treated by adjuvant treatment modalities like radiotherapy. Despite the radio-resistance of RCC itself, focal radiotherapy has been preferred as the first-line treatment modality of ISCM from RCC and only a few cases underwent surgical treatment. We describe a case of ISCM from RCC, which underwent surgical excision and pathologically confirmed. A 44-yr-old man was presented with rapid deterioration of motor weakness during focal radiotherapy for ISCM from RCC. After the surgery for removal of the tumor mass and spinal cord decompression, his motor power was dramatically improved to ambulate by himself. We report the first published Korean case of ISCM from RCC confirmed pathologically and describe our surgical experience and his clinical characteristics.

Fusion Assessment of Oblique Lumbar Interbody Fusion Using Demineralized Bone Matrix: A 2-Year Prospective Study.

OBJECTIVE: Although several studies have reported successful fusion rates after oblique lumbar interbody fusion (OLIF) using allografts or dimerized bone matrix (DBM) instead of autografts, whether OLIF can achieve satisfactory solid fusion without the use of autografts remains unclear. This study investigated the real fusion rates after OLIF using allografts and DBM, which were evaluated using both dynamic radiographs and computed tomography scans. METHODS: We enrolled 79 consecutive patients who underwent minimally invasive OLIF followed by percutaneous pedicle screw fixation. All patients were treated with OLIF between L2 and L5 and underwent radiographic and clinical follow-ups at 12, 18, and 24 months after surgery. Radiographic assessment of fusion was performed using the modified BrantigaSteffee-Fraser (mBSF) scale, which was categorized as follows: grades I (radiographic pseudoarthrosis), II (indeterminate fusion), and III (solid radiographic fusion). Other radiologic and clinical outcomes were evaluated using the following parameters: vertebral slippage distance, disc height, subsidence, Oswestry Disability Index (ODI), and visual analogue scale (VAS). RESULTS: Clinical outcomes demonstrated significant improvements in the VAS scores for back pain, leg pain, and ODI after surgery. Subsidence was present in 34 cases (35.4%) at 12 months postoperatively, which increased to 47.9% and reached 50.0% at 1.5 years and 2 years after surgery, respectively. The solid fusion rate after OLIF was 32.3% at 1 year, increased to 58.3% at 1.5 years, and reached 72.9% at 2 years. Radiographic pseudoarthrosis was 24.0% at 1 year, which decreased to 6.3% at 1.5 years and 3.1% at 2 years. CONCLUSION: OLIF is a safe and effective surgical procedure for the treatment of degenerative lumbar diseases. The mBSF scale, which simultaneously evaluates both dynamic angles and bone bridge formation, offers great reliability for the radiological assessment of fusion. Moreover, OLIF using allografts and DBM, which is performed on one or 2 levels at L2-5, can achieve satisfactory fusion rates within 2 years after surgery.

A synergistic bone sparing effect of curcumin and alendronate in ovariectomized rat.

BACKGROUND: The purpose of this study was to evaluate the therapeutic effects of combination therapy with curcumin and alendronate on bone remodeling after ovariectomy in rats. METHODS: Eighty female Sprague-Dawley rats underwent either a sham operation (the sham group) or bilateral ovariectomy (OVX). The ovariectomized animals were randomly distributed amongst four groups: untreated OVX group, curcumin-administered group, alendronate-administered group, and the combination therapy group. At 8 and 12 weeks after surgery, rats from each of the groups were euthanized. Serum biochemical markers of bone turnover, including osteocalcin and alkaline phosphatase (ALP), and the telopeptide fragment of type I collagen C-terminus (CTX) were analyzed. Bone histomorphometric parameters of the 4th lumbar vertebrae were determined by micro-computed tomography (CT). In addition, mechanical strength was determined by a three-point bending test. RESULTS: Serum biochemical markers of bone turnover in the experiment groups (curcumin administered group, alendronate administered group, and the combination therapy group) were significantly lower than in the untreated OVX group (p < 0.05). The combination therapy group had lower ALP and CTX-1 concentrations at 12 weeks, which were statistically significant compared with the curcumin only and the alendronate only group (p < 0.05). The combination therapy group had a significant increase in BMD at 8 weeks and Cr.BMD at 12 weeks compared with the curcumin-only group (p = 0.005 and p = 0.013, respectively). The three point bending test showed that the 4th lumbar vertebrae of the combination therapy group had a significantly greater maximal load value compared to that of the curcumin only and the alendronate only group (p < 0.05). CONCLUSIONS: The present study demonstrated that combination therapy with a high dose of curcumin and a standard dose of alendronate has therapeutic advantages over curcumin or alendronate monotherapy, in terms of the synergistic antiresorptive effect on bone remodeling, and improving bone mechanical strength.

Vertebral artery injury in destabilized midcervical spine trauma; predisposing factors and proposed mechanism.

BACKGROUND: By now it has been well established that vertebral artery injury (VAI) is associated with unstable cervical spine injuries resulting from blunt trauma. A more complete understanding of predisposing factors and the mechanism of injury in VAI should result in improved outcomes and reduced risk for patients with VAI associated with unstable cervical spine injury following blunt trauma. The authors report statistical outcome and hypothesis to more thoroughly examine the predisposing factors for VAI, of which management is controversial, in destabilized midcervical spine trauma. METHODS: Ninety-one of 131 consecutive patients who underwent surgery for a traumatically destabilized subaxial cervical spine were included, and results were analyzed statistically by logistic regression. RESULTS: Eighteen patients (19.8 % of 91 patients) had a VAI associated with midcervical spine trauma (C2-C6). In univariate statistical analysis, transverse foramen fracture (P = 0.002), facet dislocation (P = 0.014), and facet fracture (P = 0.001) were significant risk factors. However, only facet fracture was determined to be significant risk factor after multivariate analysis (P = 0.006, odds ratio 20.98). It is hypothesized that a VAI occurs in a midcervical spine injury when a facet fracture allows the bony compartment to impinge on the relatively narrow free space of the intervertebral foramen, which is also occupied by the cervical root. CONCLUSION: A facet fracture is the most important risk factor for VAI in patients with a destabilized midcervical spine injury. Patients with a C2-C6 facet fracture may require a definitive evaluation with vertebral artery imaging.

Retrospective report of symptomatic postoperative discal pseudocyst after lumbar discectomy.

BACKGROUND: Rarely, a symptomatic discal pseudocyst can develop after discectomy. Only very recently one clinical article and one case report about this type of pseudocyst were published: Kang and Park (J Korean Neurosurg Soc 49(1):31-36, 2011); Young PM, Fenton DS, Czervionke LF (Spine J. 9(2):e9-e15, 2009). Here, in an attempt to more clearly discriminate this peculiar cyst, the authors retrospectively report the clinical, radiological, and histological findings in 12 symptomatic patients with cystic lesions attached to an operated disc. METHODS: From January 2007 to May 2010, 12 patients who experienced recurrent symptoms after successful lumbar discectomy were diagnosed with postoperative discal pseudocyst (PDP). After discectomy, the mean time to relapsing radiculopathy was 23.3 days (range, 9-38 days) with a mean of 6.8 ± 1.3 on the visual analogue scale (VAS). PDPs were detected on magnetic resonance imaging (MRI) at 31.2 days (range, 14-60 days) after the initial surgery. Of these 12 patients, 6 were treated conservatively (group C) and 6 by surgery (group S). RESULTS: In the six patients in group C, the mean duration of relapsing pain was 77.8 days (range, 20-225 days), and near total or total regression of the cyst was detected at a mean of 82.7 days (range, 23-240 days) after initial detection by MRI. Time to spontaneous regression of PDP varied widely. In the six patients in group S, surgical treatment was administered within a few days of MRI diagnosis and achieved successful pain relief. CONCLUSIONS: Postoperative discal pseudocyst appears to develop after lumbar discectomy and can regress spontaneously.

Feasibility of C2 translaminar screw as an alternative or salvage of C2 pedicle screws in atlantoaxial instability.

STUDY DESIGN: A retrospective outcome study. OBJECTIVE: The purpose of this study was to analyze the clinical outcomes of our experience with the C2 translaminar screw technique and evaluate its feasibility as an alternative or salvage of the pedicle screw. SUMMARY OF BACKGROUND DATA: Pedicle screws are the most biomechanically stable screws for use in atlantoaxial fixation. However, in cases with elevated risk of neurovascular complications or failure of screw insertion attempts, a reliable alternative technique is required. METHODS: Fourteen patients with atlantoaxial instability underwent posterior fixation with C2 translaminar screws. Indications included traumatic instability, atlantoaxial subluxation, os odontoideum, and fusion failure after anterior fixation of a type II odontoid process fracture. A total of 26 screws were inserted and all patients were assessed both clinically and radiographically. RESULTS: No procedure-related complications or hardware failures were observed during the follow-up. Postoperative computed tomographic scans revealed laminar breach in 3 patients and none of these resulted in neurological symptoms. Radiographically demonstrated bony fusion was established in 11 patients (91.7%) at follow-up over 6 months, and 5 patients with initial neurological deficit demonstrated at least 1 grade improvement by Frankel grade. CONCLUSIONS: C2 translaminar screws provide surgeons with an expanded option for posterior fusion in high cervical lesions. This technique is safe and easy to adopt with a favorable rate of successful fusion. We believe that preoperative planning using computed tomographic scan is mandatory and use of an additional connector may reduce the stress and strain of the screws.

Curcumin as a Promising Neuroprotective Agent for the Treatment of Spinal Cord Injury: A Review of the Literature.

Curcumin is a polyphenolic chemical derived from the rhizomes of Curcuma longa. It has been used throughout the Indian subcontinent for medicinal purposes, religious events, and regional cuisine. It has various pharmacological benefits owing to its anti-inflammatory and antioxidant properties. Its neuroprotective effects on the brain and peripheral nerves have been demonstrated in several in vivo neuronal tissue studies. Because of these functional properties of curcumin, it is considered to have great potential for use in the treatment of spinal cord injuries (SCIs). Numerous immunopathological and biochemical studies have reported that curcumin can help prevent and alleviate subsequent secondary injuries, such as inflammation, edema, free radical damage, fibrosis, and glial scarring, after a primary SCI. Furthermore, following SCI, curcumin administration resulted in better outcomes of neurological function recovery as per the Basso, Beattie, and Bresnahan locomotor rating scale. However, to date, its utility in treating SCIs has only been reported in laboratories. More studies on its clinical applications are needed in the future for ensuring its bioavailability across the blood-brain barrier and for verifying the safe dose for treating SCIs in humans.

Cervical Radiculopathy Caused by Spinal Epidural Arteriovenous Fistula (SEDAVF) Without Intradural Drainage: A Case Report and Literature Review.

Spinal epidural arteriovenous fistula (SEDAVF) is a rare vascular malformation. Due to the mass effect of enlarged epidural veins and venous hypertension, progressive radiculopathy and myelopathy are likely to occur. A 33-year-old female presented with right upper extremity weakness for a month. The cause of this symptom was a SEDAVF, which was located near the C5-6-7 foramens and compressed the nerve roots. In the absence of intradural venous drainage, endovascular treatment is often difficult because of the large venous pouch. We performed endovascular trapping of the vertebral artery (VA) and loose packing of the coil material on the AVF to minimize mass effects. Immediately after embolization, the fistula was occluded, but a small new feeder vessel developed a day later. An n-butyl cyanoacrylate embolization was performed, and the fistula was successfully occluded.

The Change of Spinal Canal According to Oblique Lumbar Interbody Fusion in Degenerative Spondylolisthesis: A Prospective Observational Study.

OBJECTIVE: Oblique lumbar interbody fusion (OLIF) involves inserting large cages into the interbody disc space. This expands the spinal canal and neural foramen by stretching the ligament flavum and releasing the facet joint, resulting in indirect neural decompression. Our objective was to investigate the changes in the spinal canal and ligament flavum over time after OLIF. METHODS: This was a prospective observational study involving 30 patients who underwent OLIF L4-5 between 2015 and 2018. In total, 27 of the 30 patients underwent preoperative, early follow-up ( < 5 days), and late follow-up (10-14 months) magnetic resonance imaging to measure the area of the spinal canal and ligament flavum. Based on the results, the patients were divided into subsidence and nonsubsidence groups for further analysis. RESULTS: After OLIF, the spinal canal area gradually increased during the preoperative, early postoperative, and late postoperative periods (p < 0.001). The thickness and area of the ligament flavum decreased gradually over the same periods (p < 0.001). Low-grade subsidence (2-4.4 mm) did not influence the effects on the spinal canal and ligament. CONCLUSION: After OLIF, the spinal canal and ligament flavum gradually change, which is effective for indirect neural decompression. In addition, the effects of low-grade subsidence on the remodeling of the spinal canal and ligament flavum are insignificant.

Radiological evaluation of atlantoaxial fusion using C2 translaminar screws and C2 pedicle screws: Does the screw halo sign imply fusion failure?

The purpose of this study was to identify the criteria for atlantoaxial (AA) fusion by comparing follow-up lateral radiographs and computed tomography (CT) images. We retrospectively analyzed data from 161 consecutive patients undergoing AA fusion. Patients with a minimum of 1 year of CT follow-up after AA fusion surgery using C2 pedicle screws or translaminar screws (C2TLS) were included. Patients were followed up radiographically at 3, 6, and 12 months after surgery, and dynamic lateral radiographs were also evaluated. A total of 49 patients were analyzed, with a mean CT image follow-up of 41.6 ±â€…37.6 months. Thirty eight patients had C2 pedicle screw placement, and 11 patients underwent planned C2TLS. AA fusion with bridging bone mass formation was achieved in 45/49 (91.8%) patients. Screw halos were observed in 14/49 (28.6%) patients. Among them, final fusion failure occurred in 2 (14.3%) patients. The last follow-up CT showed no difference in the fusion failure rate according to the presence or absence of a screw halo (no halo, 5.7%; halo, 14.3%; P = .33). The differences in C1-2 segmental angles (SA) in flexion-extension dynamic lateral radiographs were 1.99 ±â€…1.62° in the fusion group and 4.37 ±â€…2.13° in the non-fusion group (P = .01). The likelihood of fusion failure increased when the SA gap was greater than 2.62° (P = .05). C2TLS placement had a significantly higher incidence of screw halos. However, the halo sign was not significantly related to final bone fusion. Bone fusion could be predicted when the SA gap of C1-2 was less than 2.62° on the dynamic radiograph.

Psoas weakness following oblique lateral interbody fusion surgery: a prospective observational study with an isokinetic dynamometer.

BACKGROUND CONTEXT: Although the surgical corridor used for oblique lateral interbody fusion (OLIF) protects the intrapsoas nerves by causing minimal compression, transient weakness remains the most commonly reported postoperative complication. PURPOSE: Using a dynamometer to evaluate how the hip flexor strength changes following OLIF. STUDY DESIGN/SETTING: A prospective observational study. PATIENT SAMPLE: Forty-six patients who underwent single or multi-level OLIF for lumbar spondylolisthesis. OUTCOME MEASURES: Isokinetic dynamometer values (peak torque, total work, average power), visual analogue scale (VAS) scores for leg pain, hypoesthesia, subjective weakness of the left hip flexor muscle, Oswestry disability index, body mass index, bone mineral density, radiologic findings of the psoas muscle (cross-sectional area, Hounsfield unit (HU), fat portion grade), and psoas retraction time. METHODS: The isokinetic muscle strength of the hip flexor was measured five times (preoperatively and postoperatively at 2 days, 1 week, 1 month, and 3 months) for both legs. The peak torque was defined as the postoperative strength of the left hip flexor muscles, and was compared to the preoperative baseline value. The strength of the left and right hip flexor muscles were also compared at each time point. For logistic regression analysis, when the peak torque was below the median value, it was defined as lower peak torque. RESULTS: Up to 1 week after surgery, the strength of the left hip flexor muscle decreased significantly (paired difference in peak torque was 22.6%, p<.001). In the results of multivariate logistic regression analysis, diabetes (odds ratio [OR]=8.43, p=.020) and the HU of the psoas muscle (OR=0.916, p=.034) were associated with lower peak torque 1 week after surgery. From 1 month after surgery, postoperative weakness of the psoas muscle was not significant. In the questionnaire survey, subjective left hip flexion weakness was reported in 8.5% (4/47) of patients 1 week after surgery, and it remained in only 2.1% (1/47) of patients after 3 months of operation. The frequency of left anterior thigh pain and hypoesthesia decreased from 85.1% (40/47) at 1 week to 2.1% (1/47) at 3 months after surgery. The mean VAS score for left anterior thigh or groin pain decreased significantly at 1 month after surgery (PO2D: 4.04±1.84, PO1M: 1.67±1.10, p<.001). CONCLUSIONS: Dynamometer measurement showed that psoas strength declined significantly up to 1 week after OLIF surgery. Patients with diabetes or lower HU of the psoas muscle showed delayed recovery from postoperative weakness of the psoas muscle. However, the weakness was insignificant from 1 month after surgery. At 3 months after surgery, the other psoas-related problems (left anterior thigh pain and hypoesthesia) also disappeared.

Effect of teriparatide on drug treatment of tuberculous spondylitis: an experimental study.

Tuberculous spondylitis often develops catastrophic bone destruction with uncontrolled inflammation. Because anti-tuberculous drugs do not have a role in bone formation, a combination drug therapy with a bone anabolic agent could help in fracture prevention and promote bone reconstruction. This study aimed to investigate the influence of teriparatide on the effect of anti-tuberculous drugs in tuberculous spondylitis treatment. We used the virulent Mycobacterium tuberculosis (Mtb) H37Rv strain. First, we investigated the interaction between teriparatide and anti-tuberculosis drugs (isoniazid and rifampin) by measuring the minimal inhibitory concentration (MIC) against H37Rv. Second, we evaluated the therapeutic effect of anti-tuberculosis drugs and teriparatide on our previously developed in vitro tuberculous spondylitis model of an Mtb-infected MG-63 osteoblastic cell line using acid-fast bacilli staining and colony-forming unit counts. Selected chemokines (interleukin [IL]-8, interferon γ-induced protein 10 kDa [IP-10], monocyte chemoattractant protein [MCP]-1, and regulated upon activation, normal T cell expressed and presumably secreted [RANTES]) and osteoblast proliferation (alkaline phosphatase [ALP] and alizarin red S [ARS] staining) were measured. Teriparatide did not affect the MIC of isoniazid and rifampin. In the Mtb-infected MG-63 spondylitis model, isoniazid and rifampin treatment significantly reduced Mtb growth, and cotreatment with teriparatide did not change the anti-tuberculosis effect of isoniazid (INH) and rifampin (RFP). IP-10 and RANTES levels were significantly increased by Mtb infection, whereas teriparatide did not affect all chemokine levels as inflammatory markers. ALP and ARS staining indicated that teriparatide promoted osteoblastic function even with Mtb infection. Cotreatment with teriparatide and the anti-tuberculosis drugs activated bone formation (ALP-positive area increased by 705%, P = 0.0031). Teriparatide was effective against Mtb-infected MG63 cells without the anti-tuberculosis drugs (ARS-positive area increased by 326%, P = 0.0037). Teriparatide had no effect on the efficacy of anti-tuberculosis drugs and no adverse effect on the activity of Mtb infection in osteoblasts. Furthermore, regulation of representative osteoblastic inflammatory chemokines was not changed by teriparatide treatment. In the in vitro Mtb-infected MG-63 cell model of tuberculous spondylitis, cotreatment with the anti-tuberculosis drugs and teriparatide increased osteoblastic function.

Indirect Decompression Using Oblique Lumbar Interbody Fusion Revision Surgery Following Previous Posterior Decompression: Comparison of Clinical and Radiologic Outcomes Between Direct and Indirect Decompression Revision Surgery.

OBJECTIVE: This study compared the radiological and clinical outcomes with transforaminal lumbar interbody fusion (TLIF) to evaluate the effect of indirect decompression through oblique lumbar interbody fusion (OLIF) as revision surgery. METHODS: We enrolled patients who underwent single-level fusion with revision surgery at the same level as the previous decompression level. We retrospectively reviewed 25 patients who underwent OLIF from 2017 to 2018 and 25 who received TLIF from 2014 to 2018. Radiologic and clinical outcomes were evaluated by cross-sectional area (CSA) of the spinal canal, thickness and area of ligamentum flavum (LF), subsidence, disc height, fusion rate, Oswestry Disability Index (ODI), and visual analogue scale (VAS). RESULTS: Compared with OLIF, the thickness and area of the LF after surgery were significantly less in TLIF, and the resulting CSA extension was also significantly higher. However, both groups showed improvement in ODI and VAS after surgery, and there was no difference between the groups. Complications related to the posterior approach in TLIF were 4 cases, and in OLIF, there were 2 cases that underwent additional posterior decompression surgery and 6 cases of transient paresthesia. CONCLUSION: Since complications associated with the posterior approach can be avoided, OLIF is a safer and useful minimally invasive surgery. Therefore, appropriate indications are applied, OLIF is a good alternative to TLIF when revision surgery is considered.

Effects of D-Serine and MK-801 on Neuropathic Pain and Functional Recovery in a Rat Model of Spinal Cord Injury.

OBJECTIVE: Neuropathic pain is a common secondary complication of spinal cord injury (SCI). N-methyl-D-aspartate (NMDA) receptor activation is critical for hypersensitivity in neuropathic pain. This activation requires the binding of both glutamate and the D-serine co-agonist to the NMDA glycine site. We evaluated the effects of D-serine on neuropathic pain after SCI and explored the underlying molecular mechanisms. METHODS: Anesthetized rats underwent T9 spinal cord contusion (130 kdyn). D-serine (500 and 1,000 mg/kg) and MK-801 hydrogen maleate (2.0 mg/kg) were injected daily for 2 weeks, starting the day after SCI. Functional outcomes were assessed according to the Basso, Beattie, and Bresnahan scale, while histological outcomes were evaluated based on lesion volume and spared tissue area. Mechanical allodynia and thermal hyperalgesia were evaluated by measuring the withdrawal threshold of a von Frey filament and hot/cold plate latency. Western blotting was performed to determine the expression levels of Trpv1, Nav1.9, calcitonin gene-related peptide (CGRP), and ß-actin in damaged tissue. RESULTS: The withdrawal threshold values and latency of the D-serine group were significantly lower than those of the noninjection group. The MK-801 group showed higher threshold values and latencies than the other groups. Western blotting showed increased Nav1.9 and Trpv1 levels and lower CGRP levels in the D-serine group, whereas the MK-801 group showed the opposite results. CONCLUSION: D-serine increases neuropathic pain after traumatic SCI by mediating the NMDA receptor. NMDA receptor antagonists alleviate neuropathic pain after traumatic SCI.