Cortical Bone Trajectory Pedicle Screw Fixation in Surgical Treatment of Monosegmental Pyogenic Lumbar Spondylodiskitis.

BACKGROUND AND STUDY OBJECT: Pedicle screw fixation has been widely used in surgical treatment for infective lumbar spondylodiskitis to prevent instability and deformity. The cortical bone trajectory pedicle screw (CBTPS) fixation is a minimally invasive posterior spinal fixation system that runs from the pedicle's entry point of the caudiomedial region toward the cephalad-divergent direction. Successful results with CBTPS fixation have been reported to treat degenerative and osteoporotic spinal diseases. This study aims to investigate the clinical feasibility of CBTPS in the surgical treatment of pyogenic lumbar spondylodiskitis. PATIENT AND METHODS: We retrospectively retrieved 20 consecutive patients from two academic centers who were surgically treated for monosegmental lumbar pyogenic spondylodiskitis. The primary surgical treatment was the anterior lumbar interbody fusion with decompression, debridement, and reconstruction using an autogenous iliac strut bone graft. One to 2 weeks after the primary surgery, patients underwent a second surgery for posterior instrumentation using conventional pedicle screws (CPS; group I) and CBTPS (group II). Radiographic parameters of the deformity angle at the fusion segment and clinical parameter of visual analog scale (VAS) scores were assessed preoperatively, postoperatively, and at the last follow-up. RESULTS: There were 10 patients in each group. The mean follow-up periods of groups I and II were 51.10 ± 6.95 and 28.60 ± 9.31 months, respectively. Intergroup analysis indicated the two groups area age-matched (p = 0.38), but initial C-reactive protein (CRP; mg/dL, p = 0.04), CRP normalization (months, p = 0.00), and follow-up duration (months, p = 0.00) were heterogeneous. Meanwhile, deformity angles (segmental lordosis) between the two groups were not significantly different preoperatively (p = 0.25), postoperatively (p = 0.13), and at last follow-up (p = 0.38). The intragroup analysis indicated a significant postoperative increase of lordosis in both group I and II (p = 0.00 and 0.04, respectively) with subsequent subsidence. Lordosis remained increased at the last follow-up with or without significance (group I, p = 0.02; group II, p = 0.62). Both groups showed significant improvement in VAS scores (group I, p = 0.00; group II, p = 0.00). CONCLUSION: In monosegmental lumbar spondylodiskitis, posterior stabilization of the anterior strut bone graft by CBTPS and CPS was comparable via the radiographic parameter of segmental lordosis or deformity angle. Our observation suggests the clinical feasibility of CBTPS in the treatment of relatively mild monosegmental pyogenic lumbar spondylodiskitis.

Lumbar Interbody Fusion and Osteobiologics for Lumbar Fusion.

Lumbar interbody fusion (LIF) is an excellent treatment option for a number of lumbar diseases. LIF can be performed through posterior, transforaminal, anterior, and lateral or oblique approaches. Each technique has its own pearls and pitfalls. Through LIF, segmental stabilization, neural decompression, and deformity correction can be achieved. Minimally invasive surgery has recently gained popularity and each LIF procedure can be performed using minimally invasive techniques to reduce surgery-related complications and improve early postoperative recovery. Despite advances in surgical technology, surgery-related complications after LIF, such as pseudoarthrosis, have not yet been overcome. Although autogenous iliac crest bone graft is the gold standard for spinal fusion, other bone substitutes are available to enhance fusion rate and reduce complications associated with bone harvest. This article reviews the surgical procedures and characteristics of each LIF and the osteobiologics utilized in LIF based on the available evidence.

Prevesicular herpes zoster lumbar radiculopathy with transient motor paresis: A case report.

RATIONALE: Herpes zoster frequently causes dermatomal vesicular rash accompanied by severe neuralgia, and reaching a differential diagnosis may be challenging before the appearance of the vesicular rash. PATIENT CONCERNS: A 40-year-old male patient visited the emergency department with a complaint of sudden onset motor weakness and ipsilateral radiating neuralgia to the Lt. thigh. He had suffered from chickenpox during childhood. DIAGNOSES: No skin lesion was present at the initial visit. The reverse Straight Leg Raise test was negative. Magnetic resonance imaging showed asymmetrically swollen dorsal root ganglion with Gadolinium enhancement. The vesicular rash that appeared on the sixth day after the symptom onset led to the diagnosis of herpes zoster. INTERVENTIONS: Antiviral agent of valacyclovir (1000 mg t.i.d.) was administered for 7 days. OUTCOMES: The patient recovered from motor weaknesses by 2 weeks from the onset of the symptom. Mild degree post-herpetic neuralgia recovered by 2 months. LESSONS: A high index of suspicion is necessary to differentiate early herpes zoster radiculitis before the appearance of vesicular rash from compressive radiculopathy. In L2-3 ipsilateral radiating pain along the dermatome or myotome, the absence of reverse Straight Leg Raise sign may be a possible factor in differentiating herpes zoster radiculitis from compressive radiculopathy.

Unstable Bony Chance Fracture Successfully Treated With Teriparatide in Patient With Ankylosed Spine: A Case Report and Review of the Literature.

Background: Ankylosed spines with ankylosing spondylitis or diffuse idiopathic skeletal hyperostosis (DISH) are prone to fractures due to osteoporosis and fracture instability from long lever arm. In such cases, surgical management is the main treatment option. Case presentation: We report a first case of successful treatment of unstable bony Chance fracture at thoracolumbar junction in DISH patient using teriparatide and review previous literature on ankylosed spine fractures treated with teriparatide. An 82-year-old male patient presented with back pain after falling from a 3 m height 3 months ago. Imaging studies showed L1 unstable flexion-distraction injury (bony Chance fracture) and intravertebral vacuum cleft in ankylosed spine due to DISH. Conservative treatment, teriparatide and orthosis, was determined as the most appropriate approach because the patient declined surgery and presented with tolerable mechanical back pain without any neurologic deficits. Solid bony union was successfully achieved without any complications after 1-year treatment. Conclusion: Although surgical management is strongly recommended for unstable fracture in ankylosed spine, non-surgical treatment including teriparatide and orthosis might be safer and effective options in bony Chance fracture without neurologic deficits and intractable mechanical pain.

Lumbar Interbody Fusion: Techniques, Pearls and Pitfalls.

Lumbar interbody fusion (LIF) is an effective and popular surgical procedure for the management of various spinal pathologies, especially degenerative diseases. Currently, LIF can be performed with posterior, transforaminal, anterior, and lateral approaches by open surgery or minimally invasive surgery (MIS). Each technique has its own advantages and disadvantages. In general, posterior LIF is a well-established procedure with good fusion rates and low complication rates but is limited by the possibility of iatrogenic injury to the neural structures and paraspinal muscles. Transforaminal LIF is frequently performed using an MIS technique and has an advantage of reducing these iatrogenic injuries. Anterior LIF (ALIF) can restore the disk height and sagittal alignment but has inherent approach-related challenges such as visceral and vascular complications. Lateral LIF and oblique LIF are performed using an MIS technique and have shown postoperative outcomes similar to ALIF; however, these approaches carry a risk of injury to psoas, lumbar plexus, and vascular structures. Herein, we provide a detailed description of the surgical procedures of each LIF technique. We shall then consider the pearls and pitfalls, as well as propose surgical indications and contraindications based on the available evidence in the literatures.

Extrusion of Biocompatible Osteoconductive Polymer (BOP) Causing Cervical Myelopathy.

BACKGROUND: As the prevalence of spinal fusion surgery has increased, reliable and safe bone graft substitutes have been developed in response. Biocompatible osteoconductive polymer (BOP) has been used as a bone graft alternative for spine surgery. We present a case of cervical myelopathy due to extrusion of BOP 23 years after surgery and discuss the pathophysiology in terms of spinal fusion. CASE DESCRIPTION: A 65-year-old man presented with a 3-month history of cervical myelopathic symptoms. Twenty-three years earlier, the patient had undergone cervical surgery for a C6-7 herniated disc with the use of BOP. Imaging studies of the cervical spine showed cord compression due to extruded BOP at C6-7. He underwent corpectomy of the C7 vertebral body and removal of the BOP for the neural decompression, combined with interbody fusion by use of an iliac bone graft and plate fixation. During the operation, crumbly fibers of the BOP were easily removed. His myelopathic symptoms improved immediately after surgery. Postoperative magnetic resonance imaging also showed successful decompression of the spinal cord. Histologically, a foreign body reaction and bony degeneration were found around the synthetic fibers of the BOP. CONCLUSIONS: Spine surgeons should recognize the pathophysiology of the BOP used for spine fusion surgery. Although BOP is not currently used for spinal surgery, patients undergoing previous surgery with the BOP can present with related complications. Revision surgery is recommended to remove the unincorporated BOP and achieve solid spine fusion.

Sex-specific and Age-specific Analgesia for Early Postoperative Pain Management After Lumbar Decompressive Surgery: A Randomized Clinical Trial.

STUDY DESIGN: This was a randomized clinical trial. OBJECTIVE: To compare the efficacy and safety of nonsteroidal anti-inflammatory drug and opioid for acute pain management after lumbar decompressive surgery. SUMMARY OF BACKGROUND DATA: Multimodal analgesia is associated with synergistic effects while reducing opioid-related adverse effects. However, there is no consensus on the ideal multimodal analgesic regimen. We assumed that each agent in various multimodal regimens under different conditions may have different effects. MATERIALS AND METHODS: This prospective randomized clinical trial recruited adult patients who underwent single-level lumbar decompressive surgery. Patients were randomized to receive our postoperative analgesic regimen including either nonsteroidal anti-inflammatory drug (celecoxib) or opioid (extended-release oxycodone) from postoperative day 3 to 14. The Visual Analog Scale (VAS) and Oswestry Back Pain Disability Index (ODI) were used to evaluate effectiveness preoperatively and on postoperative days 2, 3, 7, and 14, and at 6 months. Drug-related adverse effects were also recorded. RESULTS: One hundred patients were enrolled and 93 patients (46 patients with celecoxib vs. 47 patients with oxycodone) were randomized. No differences were observed in patient demographics and preoperative VAS and ODI between the 2 groups. VAS and ODI were not different at all postoperative time points. However, subanalysis according to sex and age, revealed significant differences in efficacy: celecoxib was effective in female individuals and oxycodone was effective in male individuals on postoperative days 7 and 14; oxycodone was effective in patients aged above 65 years on postoperative days 7 and 14. Although nausea/vomiting and constipation were more common in the oxycodone group than in the celecoxib group, other adverse effects were not different. CONCLUSIONS: In patients who underwent single-level lumbar decompressive surgery, treatment with celecoxib and oxycodone for postoperative pain management showed no significant differences in efficacy. However, subanalysis showed that each drug was effective in different ages and sex groups. LEVEL OF EVIDENCE: Level II.

Assessment of pedicle screw pullout strength based on various screw designs and bone densities-an ex vivo biomechanical study.

BACKGROUND CONTEXT: The pedicle screw fixation system has been used for various spinal disorders. Many studies have been conducted on the fixation ability of the pedicle screw, but variable results have been reported based on bone qualities, pedicle screw properties, insertion techniques, and experimental methods. STUDY DESIGN: An experimental and biomechanical study. PURPOSE: To evaluate the geometric factors of screws affecting fixation ability after assessing pullout strength based on various pedicle screw designs and different bone densities. METHODS: Nine types of pedicle screws were prepared according to the outer diameter shape (cylindrical or conical), the inner diameter shape (cylindrical or conical), and thread shape (V shape, buttress shape, and square shape). The pedicle screws were inserted into standardized polyurethane foams of Grades 5, 15, and 20. The pullout strength of each pedicle screw was determined using an MTS 858 machine (Material Testing System Corp., Minneapolis, MN, USA), and the results were analyzed statistically. RESULTS: Pullout strength based on the shape of thread was the highest in the V shape and lowest in the square shape for all foam grades (p<.05). The outer cylindrical and inner conical shape of pedicle screw showed the highest pullout strength in Grades 5 and 15 foam (p<.05). An outer cylindrical and inner conical shape with a V-shaped thread showed the highest pullout strength in all foam grades (p<.05). CONCLUSIONS: Pedicle screw with an outer cylindrical and inner conical configuration with a V-shaped thread may have maximum pullout strength, regardless of bone density.

Pyogenic arthritis of the facet joint with concurrent epidural and paraspinal abscess: a case report.

Pyogenic arthritis of lumber spinal facet joints is an extremely rare condition. There are only 40 reported cases worldwide. Most cases were associated with history of paravertebral injection, which was not found in our patient. At the time of hospital admission, he had no abnormal magnetic resonance image findings. Two weeks later, he developed pyogenic facet joint arthritis associated with paravertebral and epidural abscess. This report is the first to describe delayed presentation of pyogenic arthritis associated with paravertebral abscess and epidural infection.

Recompression of vertebral body after balloon kyphoplasty for osteoporotic vertebral compression fracture.

The purpose of this retrospective clinical study was to evaluate the factors that affect recompression of operated vertebrae after percutaneous balloon kyphoplasty (PKP) for osteoporotic vertebral compression fractures (VCFs) and assess their clinical importance. PKP has been used for VCFs with satisfactory results. Several studies about subsequent VCFs adjacent to cemented vertebrae have been reported after PKP. However, the presence and significance of recompression of operated vertebrae have not been adequately described. In total, 80 patients treated with PKP for single thoracolumbar VCFs were reviewed. The follow-up period was at least 1 year. Patients were divided into those without recompression (maintained group, n = 70) and those with recompression (recompressed group, n = 10). Plain roentgenography (preoperative, operative, and last), preoperative BMD, and preoperative MRI were checked. Age, gender, T-score in BMD, duration of symptom, compression rate (CR) of VCF, reduction rate, kyphotic angle (KA), reduction angle, intervertebral cleft (IVC), and non-PMMA-endplate-contact (NPEC) were evaluated. To evaluate the clinical results, we checked the VAS score at each follow-up period. All data were analyzed statistically. The CR for the recompressed group increased significantly after surgery and decreased at the last follow-up (p < 0.05). The last CR was not significantly different from the preoperative CR. The KA showed the same pattern. The preoperative, postoperative, and last VAS scores were significantly different from one another in both groups (p < 0.05). Between the groups, preoperative KA, postoperative KA, last KA, IVC, and NPEC were significantly different (p < 0.05). In particular, last KA, IVC, and NPEC showed highly significant differences (p < 0.001). In a correlation test for the evaluated factors, IVC (r = 0.557) and NPEC (r = 0.496) were the most significant. The presence of IVC and NPEC may play an important role in inducing recompression of treated vertebrae after PKP. Careful observation of patients with these conditions is necessary to prevent deterioration of their clinical course.

Surgical excision of the lumbar disc herniation in elementary school age.

STUDY DESIGN: A retrospective study. PURPOSE: To assess the radiological, clinical features and surgical outcomes of six patients of elementary school age with lumbar disc herniation (LDH). OVERVIEW OF LITERATURE: LDH is common in people in their fourth and fifth decades. However, the condition is extremely rare in children of elementary school age. Moreover, the clinical symptoms and treatments are different from those of adults. METHODS: We reviewed a series of 6 patients under the age of 12 years, who underwent surgery for LDH at our institution between 1992-2002. Initially, all patients were treated conservatively. The indications for surgery were failure of conservative treatment for 3 months, intractable pain and/or progressive neurological impairment. RESULTS: The surgical findings revealed a protruding disc in five cases and a ruptured disc in one. In addition, separation of the vertebral ring apophysis was observed in 3 cases. The symptoms had disappeared completely at the last follow-up. At the last follow-up, the Japanese Orthopaedic Association score was 10 points in 5 cases and 9 points in 1, and the Kirkaldy-Willis criteria was excellent in all patients. No intervertebral disc space narrowing was observed in any patient at last follow up. In addition, there were no degenerative changes in the vertebral endplate and facet joint. CONCLUSIONS: Patients with symptoms that persist for more than 3 months or those with a progressive neurological deficit must be considered for surgical discectomy.

Pregabalin as a neuroprotector after spinal cord injury in rats.

The over-expression of excitotoxic neurotransmitter, such as glutamate, is an important mechanism of secondary injury after spinal cord injury. The authors examined the neuroprotective effect of pregabalin (GP) which is known as to reduce glutamate secretion, in a rat model of spinal cord injury. Thirty-two male Sprague-Dawley rats were randomly allocated to four groups; the control group (contusion injury only), the methylprednisolone treated group, the minocycline treated group and the GP treated group. Spinal cord injury was produced by contusion using the New York University impactor (25 g-cm, at the 9th-10th thoracic). Functional evaluations were done using the inclined plane test and a motor rating scale. Anti-apoptotic and anti-inflammatory effects were evaluated by in situ nick-end labeling staining technique (TUNEL) and immunofluorescence staining of cord tissues obtained at 7 days post-injury. Pregabalin treated animals showed significantly better functional recovery, and anti-apoptotic and anti-inflammatory effects. Mean numbers of TUNEL positive cells in the respective groups were 63.5 +/- 7.4, 53.6 +/- 4.0, 44.2 +/- 3.9 and 36.5 +/- 3.6. Double staining (TUNEL and anti-CC1) for oligodendrocyte apoptosis, was used to calculate oligodendrocyte apoptotic indexes (AI), using the following formula AI = (No. of doubly stained cells/No. of anti-CC1 positive cells) x 100. Mean group AIs were 88.6, 46.7, 82.1 and 70.3%, respectively. Mean numbers of activated microglia (anti-OX-42 positive cells) in high power fields were 29.8 +/- 3.9, 22.7 +/- 4.1, 21.0 +/- 3.9 and 17.8 +/- 4.3, respectively. This experiment demonstrates that GP can act as a neuroprotector after SCI in rats, and its anti-apoptotic and anti-inflammatory effects are related to its neuroprotective effect. Further studies are needed to unveil the specific mechanism involved at the receptor level.

The apoptotic effects of oxidative stress and antiapoptotic effects of caspase inhibitors on rat notochordal cells.

STUDY DESIGN: Western blotting and flow cytometric analyses were performed using rat notochordal cells. OBJECTIVE: To demonstrate the apoptotic effect of oxidative stress and the antiapoptotic effects of caspase inhibitors on rat notochordal cells. SUMMARY OF BACKGROUND DATA: Although oxidative stress causes apoptosis in many cell types, its effect on the apoptosis of notochordal cell and antiapoptotic effects of caspase inhibitors on the oxidative stress-induced apoptosis are unknown. METHODS: Cultured rat notochordal cells were exposed to oxidative stress [500 micromol/L of hydrogen peroxide (H2O2)]. To determine the oxidative stress-induced apoptotic pathways, activations of caspases (-3, -8, and -9) as well as cleavages of Bid and poly (ADP-ribose) polymerase (PARP) were evaluated with Western blotting 6 hours after oxidative stress. To elucidate the antiapoptotic effects of caspase inhibitors on the oxidative stress induced-apoptosis, apoptotic rates of notochordal cells with or without treatment of specific caspase inhibitors (z-IETD-fmk for caspase-8, z-LEHD-fmk for caspase-9, and z-DEVD-fmk for caspase-3) were quantified by flow cytometry. RESULTS: Oxidative stress significantly increased apoptosis of rat notochordal cells (2.1% vs. 4.75%, P = 0.008) and led to activations of initiators of intrinsic (caspases-9) and extrinsic (caspase-8) pathways as well as their common executioner (caspase-3). It also caused cleavages of Bid and PARP. Flow cytometric analysis showed that inhibition of only one of the intrinsic and extrinsic pathways by caspase-9 inhibitor (4.75% vs. 3.56%, P = 0.31) and caspase-8 inhibitor (4.75% vs. 5.24%, P = 0.84) did not significantly suppress the oxidative stress-induced apoptosis. However, inhibition of both pathways by caspase-3 inhibitor significantly reduced the oxidative stress-induced apoptosis (4.75% vs. 2.64%, P = 0.008) to the control level (2.1% vs. 2.64%, P = 0.15). CONCLUSION: Oxidative stress caused apoptosis of rat notochordal cells via both intrinsic and extrinsic (Type I and Type II) pathways. Because caspase inhibitors are being used in clinical trials, inhibition of both pathways using caspase inhibitors might be of future therapeutic importance in oxidative stress-induced apoptosis of notochordal cells. Our results suggest that inhibition of inappropriate or premature oxidative stress-induced apoptosis of notochordal cells may delay the starting point of disc degeneration.

The short-term effects of electrosurgical ablation on proinflammatory mediator production by intervertebral disc cells in tissue culture.

BACKGROUND CONTEXT: Percutaneous discectomy can be performed by a variety of methods. One method, electrosurgical ablation, has been shown in a chronic animal model to alter the expression of inflammatory cytokines in degenerated discs. PURPOSE: To determine whether electrosurgical ablation has an acute direct effect on proinflammatory mediator production by disc cells. STUDY DESIGN: A short-term in vitro study using normal and interleukin (IL)-1alpha stimulated porcine disc cells cultured in alginate gel to evaluate the biochemical effects of electrosurgical ablation. METHODS: Porcine annulus and nucleus cells were embedded into alginate gels and cultured using control culture media or IL-1alpha-treated media for 6 days before ablation treatment. Treated gels were ablated by using a radiofrequency-based electrosurgical device for 5 seconds and cultured an additional 3 or 6 days. IL-1beta, IL-6, IL-8, tumor necrosis factor alpha (TNF-alpha), prostaglandin E2 (PGE2), nitric oxide (NO), and heat shock protein-70 (Hsp70) levels in culture medium were measured. Levels were normalized to DNA and compared between ablated and shams. RESULTS: For normal annulus cells, there were no significant changes in cytokine levels between ablation and sham groups. For normal nucleus cells, ablation produced significantly greater levels of IL-8 at 3 days and 6 days, Hsp70 at 3 days but not 6 days, and NO at 6 days. PGE2 was also increased at 3 days and 6 days but not significantly. For IL-1-stimulated annulus cells, IL-6 and NO in the ablation group were decreased at 3 days relative to the control group. However, IL-6, IL-8, PGE2, and Hsp70 were significantly increased in the 6-day ablation group. For degenerated nucleus cells, IL-6, IL-8, and TNF-alpha were significantly decreased in the ablation group at both 3 days and 6 days. Ablation resulted in reduced PGE2 at 3 days but not 6 and reduced Hsp70 and NO at 6 days. CONCLUSIONS: The results show that electrosurgical ablation has an acute direct effect on proinflammatory mediator production by disc cells. The effect produced depends on disc cell phenotype, the mediator, and time. These direct biologic effects may be a mechanism of pain relief after percutaneous discectomy using electrosurgical ablation. However, the measured responses are limited to the short-term (1 week), and the existence of a prolonged effect remains to be determined.