Evaluation of Gelatin/Hyaluronic Acid-Generated Bridging in a 3D-Printed Titanium Cage for Bone Regeneration.

3D-printed titanium (Ti) cages present an attractive alternative for addressing issues related to osteoporosis-induced fractures, accidental fractures, and spinal fusion surgery due to disc herniation. These Ti-based bone implants possess superior strength compared to other metals, allowing for versatile applications in orthopedic scenarios. However, when used as standalone solutions, certain considerations may arise, such as interaction with soft tissues. Therefore, to overcome these issues, the combination with hydrogel has been considered. In this study, to impart Ti with regenerative abilities a 3D-printed Ti cage was loaded with gelatin and hyaluronic acid (G-H) to improve the cell attachment ability of the Ti-based bone implants. The void spaces within the mesh structure of the 3D Ti cage were filled with G-H, creating a network of micro-sized pores. The filled G-H acted as the bridge for the cells to migrate toward the large inner pores of the 3D Ti cage. Due to the microporous surface and slow release of gelatin and hyaluronic acid, the biocompatibility of the coated Ti cage was increased with an elevation in osteoconduction as depicted by the up-regulation of bone-related gene expressions. The in vivo implantation in the rabbit femur model showed enhanced bone regeneration due to the coated G-H on the Ti cage compared to the pristine hollow Ti cage. The G-H filled the large holes of the 3D Ti cage that acted as a bridge for the cells to travel inside the implant and aided in the fast regeneration of bone.

Functional Anatomy of the Spinal Tracts Based on Evolutionary Perspectives.

The development of spinal cord represents evolutionary progression. The primitive tract is responsible for functions related to basic survival such as locomotion. In contrast, the developed tracts are involved in perceiving the external environment and controlling conscious movements. There are also differences in the arrangement of spinal tracts between the 2 categories. Tracts serving developed functions are located in the deep layer of the lateral funiculus, whereas primitive tracts occupy other areas. Decussation correlates with tract pathways, with primitive tracts projecting ipsilaterally and developing tracts decussating early. Understanding these principles provides insights into spinal tract organization.

Comparative Analysis of Radiologic Outcomes Between Polyetheretherketone and Three-Dimensional-Printed Titanium Cages After Transforaminal Lumbar Interbody Fusion.

OBJECTIVE: Transforaminal lumbar interbody fusion (TLIF) is performed worldwide with polyetheretherketone (PEEK) and titanium (Ti) cages for the treatment of degenerative lumbar diseases. The aim of this study was to compare radiologic outcomes between a PEEK and three-dimensional-printed titanium (3DP-Ti) cage after TLIF with >1 year of follow-up. METHODS: A total of 140 patients with degenerative lumbar diseases who underwent TLIF operation were included in this study. Intervertebral disc height and whole lumbar lordosis were measured and evaluated from the preoperative stage to the final follow-up. Subsidence of the cage was indicated if the cage sunk into the adjacent vertebral body or if there was a reduction in height of the fused segment by ≥3 mm during the postoperative follow-up. Migration of the cage was determined as the displacement of the interbody cage by ≥2 mm during the postoperative period. Fusion status was assessed at the 1 year and final follow-up using standard methods. RESULTS: Both disc height and lumbar lordosis were well maintained throughout the study period, and no significant differences were observed between PEEK and 3DP-Ti groups. Both PEEK and 3DP-Ti cages demonstrated low rates of cage subsidence, with no significant difference was noted. A significant cage migration rate was observed in the PEEK group and the revision operation was required for 2 patients. The fusion rate of this study was not found to be statistically significant, although the 3DP-Ti cage was known to have an improved fusion rate than PEEK cage after lumbar interbody fusion. CONCLUSIONS: Radiologic results suggest that the 3DP-Ti cage may be a better interbody cage for TLIF than is the PEEK cage.

A composite of polymethylmethacrylate, hydroxyapatite, and ß-tricalcium phosphate for bone regeneration in an osteoporotic rat model.

The purpose of this study was to test several modifications of the polymethylmethacrylate (PMMA) bone cement by incorporating osteoconductive and biodegradable materials for enhancing bone regeneration capacity in an osteoporotic rat model. Three bio-composites (PHT-1 [80% PMMA, 16% HA, 4% ß-TCP], PHT-2 [70% PMMA, 24% HA, 6% ß-TCP], and PHT-3 [30% PMMA, 56% HA, 14% ß-TCP]) were prepared using different concentrations of PMMA, hydroxyapatite (HA), and ß-tricalcium phosphate (ß-TCP). Their morphological structure was then examined using a scanning electron microscope (SEM) and mechanical properties were determined using a MTS 858 Bionics test machine (MTS, Minneapolis, MN, USA). For in vivo studies, 35 female Wister rats (250 g, 12 weeks of age) were prepared and divided into five groups including a sham group (control), an ovariectomy-induced osteoporosis group (OVX), an OVX with pure PMMA group (PMMA), an OVX with PHT-2 group (PHT-2), and an OVX with PHT-3 group (PHT-3). In vivo bone regeneration efficacy was assessed using micro-CT and histological analysis after injecting the prepared bone cement into the tibial defects of osteoporotic rats. SEM investigation showed that the PHT-3 sample had the highest porosity and roughness among all samples. In comparison to other samples, the PHT-3 exhibited favorable mechanical properties for use in vertebroplasty procedures. Micro-CT and histological analysis of OVX-induced osteoporotic rats revealed that PHT-3 was more effective in regenerating bone and restoring bone density than other samples. This study suggests that the PHT-3 bio-composite can be a promising candidate for treating osteoporosis-related vertebral fractures.

Efficacy of a newly designed helical-shaped 3D-printed titanium cage for cervical vertebral defect healing in rabbits.

Three-dimensional (3D) printed titanium (Ti-6Al-4V alloy) cages are widely used for spinal fusion applications. However, the structural design and shape of the cages are a major determinant of the optimal clinical outcome. In this study, we constructed a newly designed 3D-printed helical-shaped titanium cage (HTC) with a flexible body, and compared its healing and fusion efficacy in cervical vertebral defects after corpectomy in rabbits to that of a 3D-printed traditional titanium cage (TTC). We performed radiological examinations 1 and 16 weeks after TTC and HTC implantation. We assessed bone ingrowth in TTC and HTC using micro-computed tomography (micro-CT) and histological staining of tissue sections at 16 weeks. The radiographic data showed that the HTC-implanted group had better restoration of vertebral height than the TTC group, indicating a lower risk of cage subsidence. The micro-CT and histological observations showed that HTC promoted bone regeneration and osseointegration more effectively than TTC. Histomorphometry further revealed significant new bone formation in the HTC group compared to the TTC group. These findings demonstrate that HTC has better healing and bone fusion effects than TTC in cervical vertebral defects in rabbits, indicating its potential clinical value.

In-vivo bone remodeling potential of Sr-d-Ca-P /PLLA-HAp coated biodegradable ZK60 alloy bone plate.

Magnesium and its alloys are widely applied biomaterials due to their biodegradability and biocompatibility. However, rapid degradation and hydrogen gas evolution hinder its applicability on a commercial scale. In this study, we developed an Mg alloy bone plate for bone remodeling and support after a fracture. We further coated the Mg alloy plate with Sr-D-Ca-P (Sr dopped Ca-P coating) and Sr-D-Ca-P/PLLA-HAp to evaluate and compare their biodegradability and biocompatibility in both in vitro and in vivo experiments. Chemical immersion and dip coating were employed for the formation of Sr-D-Ca-P and PLLA-HAp layers, respectively. In vitro evaluation depicted that both coatings delayed the degradation process and exhibited excellent biocompatibility. MC3T3-E1cells proliferation and osteogenic markers expression were also promoted. In vivo results showed that both Sr-D-Ca-P and Sr-D-Ca-P/PLLA-HAp coated bone plates had slower degradation rate as compared to Mg alloy. Remarkable bone remodeling was observed around the Sr-D-Ca-P/PLLA-HAp coated bone plate than bare Mg alloy and Sr-D-Ca-P coated bone plate. These results suggest that Sr-D-Ca-P/PLLA-HAp coated Mg alloy bone plate with lower degradation and enhanced biocompatibility can be applied as an orthopedic implant.

Clinical Outcomes after Spinal Cord Stimulation According to Pain Characteristics.

OBJECTIVE: Spinal cord stimulation (SCS) is an effective treatment for chronic neuropathic pain. However, its clinical efficacy in regard to specific types of pain has not been well studied. The primary objective of this study was to retrospectively analyze the clinical outcomes of paddle-type SCS according to the type of neuropathic pain. METHODS: Seventeen patients who underwent paddle-lead SCS at our hospital were examined. Clinical outcomes were evaluated pre- and postoperatively (3 months, 1 year, and last follow-up) using the Neuropathic Pain Symptom Inventory (NPSI). The NPSI categorizes pain as superficial, deep, paroxysmal, evoked, or dysesthesia and assess the duration of the pain (pain time score). Changes in NPSI scores were compared with change in Visual analogue scale (VAS) scores. RESULTS: After SCS, the pain time score improved by 45% (independent t-test, p=0.0002) and the deep pain score improved by 58% (independent t-test, p=0.001). Improvements in the pain time score significantly correlated with improvements in the VAS score (r=0.667, p=0.003, Spearman correlation). Additionally, the morphine milligram equivalent value was markedly lower after vs. before surgery (~49 mg, pared t-test, p=0.002). No preoperative value was associated with clinical outcome. CONCLUSION: The NPSI is a useful tool for evaluating the therapeutic effects of SCS. Chronic use of a paddle-type spinal cord stimulation improved the deep pain and the pain time scores.

Reconstruction of Anterior Skull Base Fracture Using Autologous Fractured Fragments: A Simple Stitching-Up Technique.

OBJECTIVE: A displaced fracture in the anterior cranial base may be complicated by cerebrospinal fluid (CSF) rhinorrhea and enophthalmos. This study introduces a reconstruction technique with direct dural repair and reduction and fixation of the autologous fractured fragments. METHODS: Displaced fractures in the anterior cranial base were reconstructed using a stitching-up technique: A bicoronal scalp incision and frontal craniotomy was performed and the displaced bone was withdrawn. The lacerated dura was repaired primarily using a graft. Small holes were created in the intact cranial bones and the displaced harvest bone. Black silk was passed through the holes and the displaced bone was repositioned on tying the silk. Lumbar drain was not placed in any of the cases. The feasibility and outcome were evaluated. RESULTS: Five patients with displaced skull fractures of the anterior cranial base were included. All cases were men who had a direct impact on the forehead and/or eye. All the displaced fractures occurred in the orbital roof, and ethmoid bone fractures were present in 4 cases. Dural laceration was involved in 4 cases and repaired by placing artificial dura in 3 cases and a pericranial graft in 1 case. Following surgery, all cases were uneventful, and the anterior cranial fossa was well reconstructed. CSF leakage or enophthalmos did not occur in any of the cases. CONCLUSION: Direct dural repair and autologous stitching-up reconstruction using the fractured fragment could be an effective method to prevent CSF leakage and enophthalmos in displaced fractures of the anterior cranial base.

Frequency of and Reasons for Unplanned Transfers From the Inpatient Rehabilitation Facility in a Tertiary Hospital.

OBJECTIVE: To characterize the patients in the inpatient rehabilitation facility who were transferred to acute care facilities and identify the frequency of and reasons for the unplanned transfer. METHODS: Medical records of patients admitted to the inpatient rehabilitation facility from October 2017 to December 2018 were reviewed. Patients were categorized according to their diagnoses. The included patients were divided into the unplanned transfer and control groups based on whether they required to transfer to another department for acute care before completing an uninterrupted rehabilitation course. The groups were compared in terms of sex, age, length of stay, admission sources, and disease groups. The reasons for unplanned transfers were classified based on medical or surgical conditions. RESULTS: Of the 1,378 patients were admitted to the inpatient rehabilitation facility, 1,301 satisfied inclusion criteria. Among them, 121 (9.3%) were unexpectedly transferred to the medical or surgical department. The unplanned transfer group had a higher age (69.54±12.53 vs. 64.39±15.32 years; p=0.001) and longer length of stay (85.69±66.08 vs. 37.81±31.13 days; p<0.001) than the control group. The top 3 reasons for unplanned transfers were infectious disease, cardiopulmonary disease, and orthopedic problem. CONCLUSION: The unplanned transfer group had a significantly higher age and longer length of stay. The most common reason for the unplanned transfer was infectious disease. However, the proportions of those with orthopedic and neurological problems were relatively high. Therefore, further studies of these patient populations may help organize systematic strategies that are needed to reduce unplanned transfers to acute facilities for patients in rehabilitation facilities.

Comparative study on biodegradation and biocompatibility of multichannel calcium phosphate based bone substitutes.

The objective of this study was to fabricate multichannel biphasic calcium phosphate (BCP) and ß-tricalcium phosphate (TCP) bone substitutes and compare their long-term biodegradation and bone regeneration potentials. Multi-channel BCP and TCP scaffolds were fabricated by multi-pass extrusion process. Both scaffolds were cylindrical with a diameter of 1-mm, a length of 1-mm, and seven interconnected channels. Morphology, chemical composition, phase, porosity, compressive strength, ion release behavior, and in-vitro biocompatibility of both scaffolds were studied. In-vivo biodegradation and bone regeneration efficacies of BCP and TCP were also evaluated using a rabbit model for 1 week, 1 month, and 6 months. BCP exhibited superior compressive strength compared to TCP scaffold. TCP showed higher release of both calcium ions and phosphorous ions than BCP in SBF solution. Both scaffolds showed excellent in-vitro biocompatibility and upregulated the expression of osteogenic markers of MC3T3-E1 cells. In-vivo studies revealed that both cylindrical TCP and BCP scaffolds were osteoconductive and supported new bone formation. Micro-CT data showed that the bone-regeneration efficacy of TCP was higher at one month and at six months after implantation. Histological examination confirmed that TCP degraded faster and had better bone regeneration than BCP after 6 months.

A biphasic calcium phosphate ceramic scaffold loaded with oxidized cellulose nanofiber-gelatin hydrogel with immobilized simvastatin drug for osteogenic differentiation.

A novel bone scaffold containing bioceramic and biopolymer materials with an osteoinductive simvastatin molecule was developed to enhance bone regeneration. An oxidized cellulose nanofiber (OCNF)-Gelatin (Gel) hydrogel was loaded into a biphasic calcium phosphate (BCP) ceramic in which simvastatin was entrapped, resulting in a scaffold with both osteoconductive and osteoinductive properties. The fabricated scaffold showed interconnected porosity with micro- and macroporous orientation. After loading the OCNF-Gel (HG), the mechanical stability of the ceramic BCP scaffold was increased suitable for the application of hard tissue regeneration. Fourier-transform infrared spectroscopy showed that simvastatin was successfully coated on the BCPHG scaffolds. OCNF, with its slower degradation, may contribute to the sustained release of drug from the scaffold. Initially simvastatin was released from the scaffold at high levels, then was constantly and gradually released for up to 4 weeks. Pre-osteoblast MC3T3E1 cells were seeded on the scaffolds to investigate cell viability, morphology, and differentiation. The simvastatin-loaded BCPHG-S scaffolds showed better cell proliferation and spreading compared to other scaffolds. Immunostaining assays showed the expression of proteins responsible for osteogenic differentiation. Alkaline phosphatase and osteopontin were more highly expressed in the BCPHG-S scaffold than in other scaffolds. These results suggest that simvastatin-loaded BCPHG scaffolds provided physiological environments suitable for better osteogenic differentiation.

Improvement of Cognitive Function after Continuous Positive Airway Pressure Treatment for Subacute Stroke Patients with Obstructive Sleep Apnea: A Randomized Controlled Trial.

Background: Obstructive sleep apnea (OSA) is common after stroke. Various studies on continuous positive airway pressure (CPAP) therapy for OSA after stroke have been published. However, there have been no studies from Korea and Asia. The present Korean study aimed to determine whether CPAP treatment during inpatient rehabilitation of stroke patients with sleep disorders, especially OSA, improves function, cognition, sleep quality, and daytime sleepiness. Methods: This single-blind randomized controlled study included 40 stroke patients with OSA between November 2017 and November 2018. The patients were divided into the CPAP treatment group (CPAP and rehabilitation; n = 20) and control group (only rehabilitation; n = 20). The intervention period was 3 weeks. The primary outcomes were function and cognition improvements, and the secondary outcomes were sleep-related improvements. Results: CPAP treatment started at an average of 4.6 ± 2.8 days after admission. Both groups showed improvements in stroke severity, function, and cognition after the 3-week intervention. However, after the intervention, the degree of change in attention and calculation was significantly higher in the CPAP treatment group than in the control group. Additionally, the improvements in sleep quality and daytime sleepiness were greater in the CPAP treatment group than in the control group. Conclusion: CPAP treatment can improve cognitive function, sleep quality, and daytime sleepiness, and it should be considered as part of the rehabilitation program for patients with stroke. Our findings might help in the treatment of stroke patients with OSA in Korea.

Thermal cycling effect on osteogenic differentiation of MC3T3-E1 cells loaded on 3D-porous Biphasic Calcium Phosphate (BCP) scaffolds for early osteogenesis.

The application of heat stress on a defect site during the healing process is a promising technique for early bone regeneration. The primary goal of this study was to investigate the effect of periodic heat shock on bone formation. MC3T3-E1 cells were seeded onto biphasic calcium phosphate (BCP) scaffolds, followed by periodic heating to evaluate osteogenic differentiation. Heat was applied to cells seeded onto scaffolds at 41 °C for 1 h once, twice, and four times a day for seven days and their viability, morphology, and differentiation were analyzed. BCP scaffolds with interconnected porous structures mimic bone biology for cellular studies. MTT and confocal studies have shown that heat shock significantly increased cell proliferation without any toxic effects. Compared to non-heated samples, heat shock enhanced calcium deposition and mineralization, which could be visualized by SEM observation and Alizarin red S staining. Immunostaining images showed the localization of osteogenic proteins ALP and OPN on heat-shocked cells. qRT-PCR analysis revealed the presence of more osteospecific markers, osteopontin (OPN), osteocalcin, collagen type X, and Runx2, in the heat-shocked samples than in the non-heated sample. Periodic heat shock significantly upregulated both heat shock proteins (HSP70 and HSP27) in differentiated MC3T3-E1 cells. The results of this study demonstrated that periodically heat applied especially two times a day was better approach for osteogenic differentiation. Hence, this work provides a define temperature and time schedule for the development of a clinical heating device in future for early bone regeneration during the postsurgical period.

Surgical Reconstruction Using a Flanged Mesh Cage without Plating for Cervical Spondylotic Myelopathy and a Symptomatic Ossified Posterior Longitudinal Ligament.

OBJECTIVE: We introduce innovative method of cervical column reconstruction and performed the reconstruction with a flanged titanium mesh cage (TMC) instead of a plate after anterior corpectomy for cervical spondylotic myelopathy (CSM) and an ossified posterior longitudinal ligament (OPLL). METHODS: Fifty patients with CSM or OPLL who underwent anterior cervical reconstruction with a flanged TMC were investigated retrospectively. Odom's criteria were used to assess the clinical outcomes. The radiographic evaluation included TMC subsidence, fusion status, and interbody height. Thirty-eight patients underwent single-level and 12 patients underwent two-level corpectomy with a mean follow-up period of 16.8 months. RESULTS: In all, 19 patients (38%) had excellent outcomes and 25 patients (50%) had good outcomes. Two patients (4%) in whom C5 palsy occurred were categorized as poor. The fusion rate at the last follow-up was 98%, and the severe subsidence rate was 34%. No differences in subsidence were observed among Odom's criteria or between the single-level and two-level corpectomy groups. CONCLUSION: The satisfactory outcomes in this study indicate that the flanged TMC is an effective graft for cervical reconstruction.

Current Training Status of Neurosurgical Residents in South Korea: A Nationwide Multicenter Survey.

BACKGROUND: In South Korea, special legislation was introduced in December 2016 to limit residents' training time to a maximum of 80 hours per week. The aim of this study was to survey the current training system and environment of neurosurgical residents and to find ways to improve the quality of neurosurgical training. METHODS: The questionnaire survey included 373 neurosurgical residents at 66 training hospitals nationwide, who were members of the Korean Neurosurgical Society. The survey method included a questionnaire link through a text message and was carried out anonymously. The survey was conducted for 7 days and targeted a total of 106 residents (28.4%). RESULTS: Most respondents selected "excessive training time" as a reason for dissatisfaction with the training environment (n = 61, 57.5%), followed by "limited number of opportunities for surgery" (n = 50, 47.2%), and "little experience for research" (n = 42, 39.6%). Respondents still believe that they have to work excessively longer, even after 80 hours of training per week. CONCLUSIONS: The major reason that neurosurgical residents are dissatisfied with the current training system and environment is the excessive time spent on it. These survey results are expected to be used as the basis for improvement of the residents' training system and work environment in South Korea.

Implications of Mechanical Endovascular Thrombectomy for Acute Basilar and Posterior Cerebral Artery Occlusion.

OBJECTIVE: Protocols for posterior circulation ischemic stroke have not been established by randomized clinical trials. Mechanical endovascular thrombectomy (MET) devices are evolving, and many of these devices already developed or in development are suitable for posterior circulation MET. MATERIALS AND METHODS: We investigated the medical records of patients who underwent MET for posterior circulation ischemic stroke from January 2012 to August 2016. Fifteen patients were included. MET was performed in patients with or without injected intravenous tissue plasminogen activator. MET was considered in patients with a National Institute of Health Stroke Scale score of 4 or more, older than 18 years, with definite occlusion of the basilar artery or posterior cerebral artery (PCA), and who arrived at the hospital within 24 hours from onset. RESULTS: The direct catheter aspiration technique was used in five cases, and the stent retrieval technique was used in seven cases. The stent retrieval technique with the direct aspiration technique was used in three cases. Recanalization failed in two cases. Basilar occlusion without PCA involvement is the only effective factor of successful recanalization (p = 0.03). Successful recanalization (p = 0.005) and the presence of a posterior communicating artery (p = 0.005) affected the good outcome at discharge. CONCLUSION: An early diagnosis and active MET may improve the patient outcome. MET may help recanalization and good flow restoration and the potential for a good outcome.

Pharmacological target therapy of neuropathic pain and patient-reported outcomes in patients with chronic low back pain in Korea: Results from the NLBP Outcomes Research.

A number of studies have demonstrated an association of neuropathic pain and chronic low back pain (CLBP), but the outcome difference in each medical management is poorly understood. This study is aimed to investigate treatment patterns of neuropathic pain in CLBP patients and to explore patient-reported outcomes (PROs) including quality of life (QoL) and functional disability by treatment patterns.Data were extracted from the neuropathic low back pain (NLBP) outcomes research. It was a multicenter and cross-sectional study in which 1200 patients were enrolled at 27 general hospitals, from 2014 to 2015. Of total, 478 patients classified as neuropathic pain were used for this subgroup analysis. The patients were divided into 2 groups according to treatment patterns (with vs. without the targeted therapy [TT] of neuropathic pain). Demographic and clinical features were collected by chart reviews and PROs were measured by patient's survey. QoL was assessed by EuroQoL 5-dimension (EQ-5D) questionnaire. Functional disability was measured by the Quebec Back Pain Disability Scale (QBPDS). Multiple linear regression analyses were conducted to compare the PROs between TT group and non-targeted therapy (nTT) group.Among the NLBP patients (mean age 63years, female 62%), EQ-5D index, EuroQoL-Visual Analog Scale (EQ-VAS), and QBPDS Scores (mean ±â€Šstandard deviation) were 0.40 ±â€Š0.28, 54.98 ±â€Š19.98, and 46.03 ±â€Š21.24, respectively. Only 142 (29.7%) patients had pharmacological TT of neuropathic pain. Univariate analyses revealed no significant mean differences between TT group and nTT group in the EQ-5D index (0.41 ±â€Š0.27 and 0.39 ±â€Š0.28), EQ-VAS (56.43 ±â€Š18.17 and 54.37 ±â€Š20.69), and QBPDS (45.31 ±â€Š21.32 and 46.31 ±â€Š21.24). After adjustment with covariates, TT group had higher scores of EQ-5D index (ß = 0.07; P < 0.01) and EQ-VAS (ß = 4.59; P < 0.05) than the nTT group. The TT group's QBPDS score was lower than the nTT group, although its statistical significance still has not been reached (ß = -4.13; P = 0.07).We found that considerable proportion of the NLBP patients remains untreated or undertreated. Although TT group had significantly better QoL than nTT group, only 29.7% of NLBP patients had pharmacological TT. Therefore, clinicians should consider using TT for better QoL of neuropathic pain patients.

Prevalence of Neuropathic Pain and Patient-Reported Outcomes in Korean Adults with Chronic Low Back Pain Resulting from Neuropathic Low Back Pain.

STUDY DESIGN: A noninterventional, multicenter, cross-sectional study. PURPOSE: We investigated the prevalence of neuropathic pain (NP) and patient-reported outcomes (PROs) of the quality of life (QoL) and functional disability in Korean adults with chronic low back pain (CLBP). OVERVIEW OF LITERATURE: Among patients with CLBP, 20%-55% had NP. METHODS: Patients older than 20 years with CLBP lasting for longer than three months, with a visual analog scale (VAS) pain score higher than four, and with pain medications being used for at least four weeks before enrollment were recruited from 27 general hospitals between December 2014 and May 2015. Medical chart reviews were performed to collect demographic/clinical features and diagnosis of NP (douleur neuropathique 4, DN4). The QoL (EuroQoL 5-dimension, EQ-5D; EQ-VAS) and functional disability (Quebec Back Pain Disability Scale, QBPDS) were determined through patient surveys. Multiple linear regression analyses were performed to compare PROs between the NP (DN4≥4) and non-NP (DN4<4) groups. RESULTS: A total of 1,200 patients (females: 65.7%; mean age: 63.4±13.0 years) were enrolled. The mean scores of EQ-5D, EQ-VAS, and QBPDS were 0.5±0.3, 55.7±19.4, and 40.4±21.1, respectively. Among all patients, 492 (41.0%; 95% confidence interval, 38.2%-43.8%) suffered from NP. The prevalence of NP was higher in male patients (46.8%; p<0.01), in patients who had pain based on radiological and neurological findings (59.0%; p<0.01), and in patients who had severe pain (49.0%; p<0.01). There were significant mean differences in EQ-5D (NP group vs. non-NP group: 0.4±0.3 vs. 0.5±0.3; p<0.01) and QBPDS (NP group vs. non-NP group: 45.8±21.2 vs. 36.3±20.2; p<0.01) scores. In the multiple linear regression, patients with NP showed lower EQ-5D (ß=-0.1; p<0.01) and higher QBPDS (ß=7.0; p<0.01) scores than those without NP. CONCLUSIONS: NP was highly prevalent in Korean patients with CLBP. Patients with CLBP having NP had a lower QoL and more severe dysfunction than those without NP. To enhance the QoL and functional status of patients with CLBP, this study highlights the importance of appropriately diagnosing and treating NP.

Use of a C1-C2 Facet Spacer to Treat Atlantoaxial Instability and Basilar Invagination Associated with Rheumatoid Arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease that often affects the craniovertebral junction. RA is associated with atlantoaxial instability and basilar invagination; the detailed presentations vary. Surgical treatment of atlantoaxial instability and basilar invagination caused by RA is challenging due to anatomic complexity and poor bone quality. The prevailing procedure is posterior occipitocervical fixation after transoral decompression or posterior decompression followed by occipitocervical fixation. However, these surgical modalities inevitably severely limit neck motion and cause dysesthesia of the C2 dermatome. CASE DESCRIPTION: We report our surgical experience with a C1-C2 facet spacer, specifically the usual cervical cage containing an autologous bone chip combined with a C1 lateral mass screw and a C2 pedicle without resection of C2 roots. The facet space was maintained on the 3-year follow-up radiograph. CONCLUSIONS: This method effectively reduces BI and allows AAI fixation without significantly compromising neck motion or causing C2 dermatome dysesthesia.