Bone Substitute Options for Spine Fusion in Patients With Spine Trauma-Part II: The Role of rhBMP.

In Part II, we focus on an important aspect of spine fusion in patients with spine trauma: the pivotal role of recombinant human bone morphogenetic protein-2 (rhBMP-2). Despite the influx of diverse techniques facilitated by technological advancements in spinal surgery, spinal fusion surgery remains widely used globally. The persistent challenge of spinal pseudarthrosis has driven extensive efforts to achieve clinically favorable fusion outcomes, with particular emphasis on the evolution of bone graft substitutes. Part II of this review aims to build upon the foundation laid out in Part I by providing a comprehensive summary of commonly utilized bone graft substitutes for spinal fusion in patients with spinal trauma. Additionally, it will delve into the latest advancements and insights regarding the application of rhBMP-2, offering an updated perspective on its role in enhancing the success of spinal fusion procedures.

Development of a novel PLDLA/ß-TCP composite-based biodegradable anterior cervical plate and screw system.

We investigated the effectiveness and safety of a new composite-based biodegradable anterior cervical plate/screw (ACPS) system for the anterior cervical discectomy and fusion (ACDF) fixation. A biocomposite in combination with 30 wt% ß-tricalcium phosphate (ß-TCP; a biodegradable ceramic having osteoconductive ability) and 70 wt% poly-l/d-lactide copolymer (PLDLA; a biodegradable polymer) was developed and used in the ACPS device, comprising one plate and four screws for fixation. Based on a literature review, a clinically required period of performance maintenance was set as 16 weeks, and to verify the performance for a period of 16 weeks or more, the test was conducted for 26 weeks. Following ISO 13781:2017 testing protocols, an in vitro degradation test was performed to verify the performance and evaluate the decomposition characteristics of the biodegradable ACPS system. Using an animal model as a preclinical investigation, the prepared ACPS device was implanted into five mongrel dogs weighing over 30 kg to evaluate the detachment prevention effect of the ACPS system on polyether ether ketone (PEEK) cage after ACDF. By week 26, the molecular weight was decreased by 45.35% for the plate and 52.56% for the screw; the bending strength of the plate was decreased by approximately 26.2% when compared with the initial stage. The torsional yield strength and pullout strength of the screw was increased by 52.31% and 5.3%, respectively by week 2 and then subsequently decreased until week 26. No detachment or dislocation of the inserted PEEK cage was observed for 26 weeks in vivo study. These findings recommend that the ACPS system might be a promising biodegradable tool for the fixation of interbody implants and supporting the fusion in an ACDF model. Furthermore, additional clinical trials are planned for the future.

Is it true that treatment in patients with Subaxial Cervical Spine Injury Classification System (SLICS) 4 is the surgeon's choice?

BACKGROUND: The Subaxial Cervical Spine Injury Classification System (SLICS) is a commonly used algorithm for diagnosing and managing subaxial cervical spine trauma. A SLIC score 4 suggests either surgery or non-surgically treatment depending on the surgeon's experience and patient's conditions. OBJECTIVE: Prognosis and treatment results were analyzed in patients with SLIC score 4. METHODS: The patients with SLIC score 4 were retrospectively reviewed from 2012 to 2019. Forty-one patients were included and divided into two groups: non-surgically treated and surgically treated. Demographic data and radiographs were analyzed. Statistical analysis was performed to determine the difference between the two clinical groups. RESULTS: Twenty-two patients were non-surgically treated, and nineteen patients were surgically treated. There was no neurological deterioration in both groups. However, there was no statistically significant difference in the last follow-up AISA and Nurick grade (p> 0.05). There was no significant difference in the number of patients who showed improvement when comparing the initial and the last follow-up neurological status (p> 0.05). CONCLUSION: Regardless of the treatment method, the spinal cord injury patients with SLICS point 4 showed a relatively good prognosis. Patients with SLIC score 4 could be treated non-surgically or surgically based on the surgeon's experience and factors associated with the patient's acute health status and chronic comorbidities.

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.

Preliminary Study on Effect of Lactiplantibacillus plantarum on Osteoporosis in the Ovariectomized Rat.

Osteoporosis is a growing global health concern primarily associated with decreased estrogen in postmenopausal women. Recently, some strains of probiotics were examined for potential anti-osteoporotic effects. This study intended to evaluate the impacts of Lactiplantibacillus plantarum MGE 3038 strain (MGE 3038) in ovariectomized rats. For this purpose, twelve weeks old female Wistar rats (n=21; 250-300 g) were divided into 3 groups; ovariectomy (OVX) group, OVX/MGE 3038 group and Sham group (control). In these groups; two went through respective OVX and one had daily MGE 3038 administration through oral gavage. Prior to 16 weeks after OVX, we collected blood samples and extracted the tibiae. We scanned the extracted tibiae by in-vivo micro-computed tomography (micro-CT) and evaluated pathology by hematoxylin and eosin (H&E) and Masson's trichrome staining. The serum levels of C-telopeptide of type I collagen (CTX), osteocalcin (OC), and the receptor activator of nuclear factor-ĸB ligand (RANKL) were examined. The OVX/MGE 3038 group showed increases in bone mineral density, trabecular bone volume, trabecular number, and trabecular thickness (Tb.Th), and a decrease in trabecular spacing than the OVX group. However, OVX/MGE 3038 group and control group were measurably comparable in Tb.Th. Micro-CT, H&E, and Masson's trichrome findings exhibited increased preservation and maintenance of trabecular bone structure in the OVX/MGE 3038 group in comparison to the OVX group. In serum, the levels of CTX, OC and RANKL were significantly different between the OVX and OVX/MGE 3038 groups. Taken together, L. plantarum MGE 3038 could be helpful for the treatment of osteoporosis.

Electron Microscopic Study in the Rat Model of Electrically Injured Myelopathy: Preliminary Report.

Objective: The patient with electrically injured myelopathy showed mild motor weakness without somatosensory pathway abnormalities. Few reports have been reported on the pathophysiological mechanisms of electrically injured myelopathy, and there is controversy about the exact pathological causes. This study aimed to investigate the ultrastructural changes in the electron microscopic findings of electrical spinal cord injury. Methods: Nine rats were used in this study. We performed 7 electrical shocks (frequency, 120 Hz; pulse width, 0.9 ms; duration, 3 seconds; current, 99 mA) using an electroconvulsive therapy (ECT) apparatus (57800 ECT unit; UGO BASILE). We used one ear and one contralateral hind limb as entry and exit sites, respectively. We only enrolled rats with hind limb weakness and performed electron microscopy evaluations of the spinal cord on the first day and 4 weeks after injury. Results: On the first day after injury, an electron microscopic examination showed a directly damaged area that appeared to be torn as physical damage, damaged myelin sheath, vacuolated axons in the myelin sheath, swollen Golgi apparatus, and injured mitochondria. Looking at changes in motor and sensory nerves, the sensory neurons showed recovered mitochondria and Golgi apparatus 4 weeks after injury; however, motor neurons still showed injured mitochondria, swollen Golgi apparatus, and endoplasmic reticulum. Conclusion: This study showed that recovery from ultrastructural injury was more rapid in sensory neurons than in motor neurons.

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.

Early Decompression in Acute Spinal Cord Injury : Review and Update.

Spinal cord injury (SCI) has a significant negative effect on the quality of life due to permanent neurologic damage and economic burden by continuous treatment and rehabilitation. However, determining the correct approach to ensure optimal clinical outcomes can be challenging and remains highly controversial. In particular, with the introduction of the concept of early decompression in brain pathology, the discussion of the timing of decompression in SCI has emerged. In addition to that, the concept of "time is spine" has been added recently, and the mortality and complications caused by SCI have been reduced by providing timely and professional treatment to patients. However, there are many difficulties in establishing international clinical guidelines for the timing of early decompression in SCI because policies for each country and medical institution differ according to the circumstances of medical infrastructure and economic conditions in the surgical treatment of SCI. Therefore, we aim to provide a current review of timing of early decompression in patient with SCI.

Bone Substitute Options for Spine Fusion in Patients With Spine Trauma-Part I: Fusion Biology, Autografts, Allografts, Demineralized Bone Matrix, and Ceramics.

Spinal trauma accounts for a large portion of injuries to the spine area, particularly as societies are entering an era of aging populations. Consequently, spine fractures accompanied by osteoporosis are becoming more prevalent. Achieving successful fusion surgery in patients with spine fractures associated with osteoporosis is even more challenging. Pseudarthrosis in the spine does not yield clinically favorable results; however, considerable effort has been made to achieve successful fusion, and the advancement of bone graft substitutes has been particularly crucial in this regard. Autograft bone is considered the best fusion material but is limited in use due to the quantity that can be harvested during surgery and associated complications. Accordingly, various bone graft substitutes are currently being used, although no specific guidelines are available and this mainly depends on the surgeon's choice. Therefore, the purpose of this review, across part I/II, is to summarize bone graft substitutes commonly used in spine surgery for spine fusion in patients with spine trauma and to update the latest knowledge on the role of recombinant human bone morphogenetic protein-2.

Characterization of Fecal Microbiomes of Osteoporotic Patients in Korea.

An imbalanced gut microbiome has been linked to a higher risk of many bone-related diseases. The objective of this study was to discover biomarkers of osteoporosis (OP). So, we collected 76 stool samples (60 human controls and 16 OP patients), extracted DNA, and performed 16S ribosomal ribonucleic acid (rRNA) gene-based amplicon sequencing. Among the taxa with an average taxonomic composition greater than 1%, only the Lachnospira genus showed a significant difference between the two groups. The Linear Discriminant Effect Size analysis and qPCR experiments indicated the Lachnospira genus as a potential biomarker of OP. Moreover, a total of 11 metabolic pathways varied between the two groups. Our study concludes that the genus Lachnospira is potentially crucial for diagnosing and treating osteoporosis. The findings of this study might help researchers better understand OP from a microbiome perspective. This research might develop more effective diagnostic and treatment methods for OP in the future.

Erratum: Validation of the European Quality of Life-5 Dimensions, 3-Level Version (EQ-5D-3L) in Patients With Osteoporotic Vertebral Fracture and Comparing Their Health-Related Quality of Life with That of the General Population in Korea.

[This corrects the article on p. 64 in vol. 18, PMID: 35557648.].

Review: Steroid Use in Patients With Acute Spinal Cord Injury and Guideline Update.

Acute spinal cord injury (SCI) is a devastating condition that causes enormous damage to a patient's physical, mental, and economic situation and requires a multidisciplinary approach to treatment. Research on SCI has been performed for a long time, and the management of SCI has developed dramatically in recent decades as a mechanism of injury and the pathophysiology of SCI have been revealed from the primitive stage in the past. In the treatment of patients with acute SCI, there is a lot of debate regarding surgical treatment strategies and pharmacological management, such as steroid use. In particular, the efficacy of steroid use, such as methylprednisolone sodium succinate, has been increasing and decreasing and is still intensely debated. The practice guidelines reported so far for this are also at the "suggest" stage with weak recommendations. Therefore, this review aims to summarize the effects of steroid use on SCI. This review provides an overview of current practical guidelines and clinical studies on steroid use in patients with SCI.

Validation of the European Quality of Life-5 Dimensions, 3-Level Version (EQ-5D-3L) in Patients With Osteoporotic Vertebral Fracture and Comparing Their Health-Related Quality of Life With That of the General Population in Korea.

Objective: This study examined the validity of the European Quality of Life-5 dimensions, 3-Level version (EQ-5D-3L) in patients with osteoporotic vertebral compression fractures (OVCF) and compared the health-related quality of life (HRQOL) of these patients with that of the general population in Korea. Methods: Study participants completed several questionnaires, such as the EQ-5D-3L, 12-item short-form health survey version 2.0 (SF-12v2), Roland-Morris disability questionnaire (RMQ), and Pain Numeric Rating Scale (Pain NRS). Spearman's correlation analyses of the questionnaire results were conducted to examine the discriminant and convergent validity of the EQ-5D-3L. Finally, EQ-5D-3L results from study participants were compared with those from the comparison group of the general population that were match-sampled according to age and sex from the 2013 Korean National Health and Nutritional Examination Survey. Results: Spearman's correlation coefficients between EQ-5D-3L and pain NRS, SF-12v2, and RMQ were statistically significant. The coefficients between the relevant dimensions, such as mobility in the EQ-5D-3L and physical functioning in the SF-12v2, were higher than those between irrelevant ones. Problems reported by study participants in each dimension of EQ-5D-3L showed statistically significant lower scores in pain NRS, PCS, and MCS from the SF-12v2 and RMQ scores. In comparison with the general population, the problems reported in the patient group were statistically higher than those reported by the general population. Conclusion: This study showed that EQ-5D-3L will be useful for patients with OVCF in Korea because it could be valid. The HRQOL of patients with OVCF was very low in all dimensions of the EQ-5D-3L.

Effectiveness of nasotracheal intubation in anterior cervical surgery including C3 lesions.

OBJECTIVE: Anterior approach cervical surgery is widely used for accessing C3 lesions. When operating with an anterior approach, the surgical field is obstructed by mandible. Neck extension is popular method to secure better surgical field but risk devastating neurological damage. To overcome this limited surgical field without neck extension, we adopted nasotracheal intubation and evaluated its efficiency. METHODS: We retrospectively analyzed 16 patients who underwent anterior cervical discectomy or corpectomy of C3 lesions via nasotracheal intubation. We enrolled an additional 29 patients who underwent anterior cervical discectomy or corpectomy of C3 lesions via orotracheal intubation as a control group. All patients had been diagnosed with cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament. We measured the mandibular-cervical angle, which is the angle between the lower mandibular line and anterior vertebral line. RESULTS: The mandibular-cervical angle was increased by 7.3 with nasotracheal intubation compared to orotracheal intubation. CONCLUSIONS: Nasotracheal intubation is an effective surgical option for securing the surgical field without neck extension in anterior cervical surgery including C3 lesions.

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.

Sudden bilateral foot drop due to dorsally unilateral migration of the herniated lumbar disc: A case report.

BACKGROUND: Due to the anatomical characteristics of the anterior epidural space, dorsal migration of material from herniated lumbar disc is quite rare. Also, bilateral foot drop due to unilateral dorsal migration of disc herniation is extremely rare. This report presents a case of sudden bilateral foot drop caused by the unilateral dorsal migration of material from a herniated lumbar disc. CASE DESCRIPTION: A 51-year-old male presented with sudden onset severe leg pain with bilateral foot drop. The patient was referred to our emergency department by a local clinic. Neurological examination showed bilateral ankle and big toe dorsiflexion weakness grade 1. There was no perianal anesthesia, anal sphincter weaknesses, or voiding difficulty. Apart from essential hypertension, this patient's medical history was unremarkable. Magnetic resonance imaging showed that intervertebral disc material in the dorsal extradural space at the L3-4 level had compressed the dural sac from the left side to the center. We performed an emergency operation. The pathologic result revealed fibrous cartilaginous materials. After the operation, the leg pain was markedly resolved. At postoperative three months, the patient showed improvement of foot drop. CONCLUSION: We recommended emergent mass removal, which produced a favorable outcome.