Cages In Patients Research Articles

The SNAP Trial: 2-Year Results of a Double-Blind Multicenter Randomized Controlled Trial of a Silicon Nitride Versus a PEEK Cage in Patients After Lumbar Fusion Surgery.

Study Design:Randomized controlled trial.Objectives:Lumbar interbody fusion with cages is performed to provide vertebral stability, restore alignment, and maintain disc and foraminal height. Polyetheretherketone (PEEK) is commonly used. Silicon nitride (Si3N4) is an alternative material with good osteointegrative properties. This study was designed to assess if Si3N4 cages perform similar to PEEK.Methods:A non-inferiority double-blind multicenter RCT was designed. Patients presenting with chronic low-back pain with or without leg pain were included. Single- or double-level instrumented transforaminal lumbar interbody fusion (TLIF) using an oblique PEEK or Si3N4 cage was performed. The primary outcome was the Roland-Morris Disability Questionnaire (RMDQ). The non-inferiority margin for the RMDQ was 2.6 points on a scale of 24. Secondary outcomes included the Oswestry Disability Questionnaire (ODI), Visual Analogue Scales (VAS), SF-36 Physical Function, patient and surgeon Likert scores, radiographic evaluations for subsidence, segmental motion, and fusion. Follow-up was planned at 3, 6, 12, and 24-months.Results:Ninety-two patients were randomized (i.e. 48 to PEEK and 44 to Si3N4). Both groups showed good clinical improvements on the RMDQ scores of up to 5-8 points during follow-up. No statistically significant differences were observed in clinical and radiographic outcomes. Mean operative time and blood loss were statistically significantly higher for the Si3N4 cohort. Although not statistically significant, there was a higher incidence of complications and revisions associated with the Si3N4 cage.Conclusions:There was insufficient evidence to conclude that Si3N4 was non-inferior to PEEK.

Cost Analysis With Use of Expandable Cage or Cement in Single level Thoracic Vertebrectomy in Metastasis.

Study Design:Retrospective case series.Objective:Patient with metastatic cancer frequently require spinal operations for neural decompression and stabilization, most commonly thoracic vertebrectomy with reconstruction. Objective of the study was to assess economic aspects associated with use of cement versus expandable cage in patients with single level thoracic metastatic disease. We also looked at the differences in the clinical, radiological, complications and survival differences to assess non-inferiority of PMMA over cages.Methods:The electronic medical records of patients undergoing single level thoracic vertebrectomy and reconstruction were reviewed. Two groups were made: PMMA and EC. Totals surgical cost, implant costs was analyzed. We also looked at the clinical/ radiological outcome, complication and survival analysis.Results:96 patients were identified including 70 one-level resections. For 1-level surgeries, Implant costs for use of cement—$75 compared to $9000 for cages. Overall surgical cost was significantly less for PMMA compared to use of EC. No difference was seen in clinical outcome or complication was seen. We noticed significantly better kyphosis correction in the PMMA group.Conclusions:Polymethylmethacrylate cement offers significant cost advantage for reconstruction after thoracic vertebrectomy. It also allows for better kyphosis correction and comparable clinical outcomes and non-inferior to cages.

Two-year results of a double-blind multicenter randomized controlled non-inferiority trial of polyetheretherketone (PEEK) versus silicon nitride spinal fusion cages in patients with symptomatic degenerative lumbar disc disorders.

During lumbar spinal fusion, spacer cages are implanted to provide vertebral stability, restore sagittal alignment, and maintain disc and foraminal height. Polyetheretherketone (PEEK) is commonly used by most spine surgeons. Silicon nitride (Si3N4) is a less well-known alternative although it was first used as a spacer in lumbar fusion over 30 years ago. The present study was designed to see if Si3N4 cages would perform similarly to PEEK in a randomized controlled trial. A non-inferiority multicenter 100-patient study was designed where both the observer and patient were blinded. Single- or double-level transforaminal lumbar interbody fusion with pedicle screw fixation using an oblique PEEK or Si3N4 cage was performed. The primary non-inferiority outcome was the Roland-Morris Disability Questionnaire (RMDQ). Secondary measures included the Oswestry Disability Questionnaire, Visual Analogue Scales (VAS) for back and leg pain, SF-36 Physical and Mental Function indices, patient and surgeon Likert scores on perceived recovery, and X-ray and CT radiological evaluations for subsidence, segmental motion, and fusion. Follow-up evaluations occurred at 3, 6, 12, and 24 months. After exclusions for protocol violations and canceled surgeries, 92 patients were randomized (i.e., 48 for PEEK and 44 for Si3N4). There were no differences in baseline demographics, pre-operative disabilities, or pain scores between the groups. Both treatment arms showed significant improvements in disability, pain, and recovery scores. No significant differences were observed for subsidence, segmental motion, or fusion. For the primary outcome (i.e., RMDQ scores), the non-inferiority of Si3N4 compared to PEEK could not be established using the original protocol criteria. However, the comparison was undermined by larger than anticipated patient fallout coupled with higher than expected RMDQ score standard deviations. A post hoc analysis coupled with a more extensive review of the literature was conducted which resulted in the selection of a revised clinically justified non-inferiority margin; and using this method, the non-inferiority of Si3N4 was affirmed. This study demonstrated that the use of either PEEK or Si3N4 cages is safe and effective for patients undergoing lumbar spine fusion for chronic degenerative disc disease.

Cerebral arterial gas embolism in a patient with hypoplastic left heart syndrome treated with emergent hyperbaric oxygen: case report

A 30-year-old female with a history of seizure disorder and hypoplastic left heart syndrome treated with a Norwood procedure in 1986 followed by a modified non-fenestrated Fontan (Left SVC to IVC to pulmonary arteries) with a known baffle leak presented to the emergency department. On day of presentation, the patient became unresponsive, with perioral cyanosis, rightward gaze and a left facial droop near the end of a platelet transfusion. An emergent non-contrast head CT revealed intracranial air in the right MCA distribution. She was taken to the hyperbaric chamber and was treated with a U.S. Navy Table 6 in a multiplace chamber with no extensions. Ten minutes into the treatment patient became more alert and spontaneously asked questions. The following day she was treated with a U.S. Navy Table 5. Patient had repeat CT of the head, which showed resolution of intracerebral gas and small areas of ischemia in right frontal lobe and right caudate. On hospital day five neurologic exam was normal, with 5/5 strength and no residual deficits. Treating the patient was a concern because patient has a single ventricle, in which the pulmonary artery is connected directly to the vena cava. There is very little data regarding the effects of hyperbaric oxygen (HBO2)therapy on single-ventricle physiology. Only two case reports of three pediatric patients treated with HBO2 for CAGE in a similar setting are known. In these cases the patients had improvements in their symptoms following HBO2. These cases and ours indicate HBO2 is feasible and indicated for CAGE in patients with cyanotic congenital heart disease.

Cerebral arterial gas embolism in a patient with hypoplastic left heart syndrome treated with emergent hyperbaric oxygen: case report

A 30-year-old female with a history of seizure disorder and hypoplastic left heart syndrome treated with a Norwood procedure in 1986 followed by a modified non-fenestrated Fontan (Left SVC to IVC to pulmonary arteries) with a known baffle leak presented to the emergency department. On day of presentation, the patient became unresponsive, with perioral cyanosis, rightward gaze and a left facial droop near the end of a platelet transfusion. An emergent non-contrast head CT revealed intracranial air in the right MCA distribution. She was taken to the hyperbaric chamber and was treated with a U.S. Navy Table 6 in a multiplace chamber with no extensions. Ten minutes into the treatment patient became more alert and spontaneously asked questions. The following day she was treated with a U.S. Navy Table 5. Patient had repeat CT of the head, which showed resolution of intracerebral gas and small areas of ischemia in right frontal lobe and right caudate. On hospital day five neurologic exam was normal, with 5/5 strength and no residual deficits. Treating the patient was a concern because patient has a single ventricle, in which the pulmonary artery is connected directly to the vena cava. There is very little data regarding the effects of hyperbaric oxygen (HBO2) therapy on single-ventricle physiology. Only two case reports of three pediatric patients treated with HBO2 for CAGE in a similar setting are known. In these cases the patients had improvements in their symptoms following HBO2. These cases and ours indicate HBO2 is feasible and indicated for CAGE in patients with cyanotic congenital heart disease.

Two-year Clinical and Radiographic Results with a Multidimensional, Expandable Interbody Implant in Minimally Invasive Lumbar Spine Surgery.

IntroductionMinimally invasive spine surgery has become more prevalent in recent years, but the delivery of interbody devices with small footprints may insufficiently restore the disc space, which may lead to instability and non-union. Vertically expandable interbody implants have partially addressed this limitation, but lateral fusion support remains a concern. The purpose of this study was to evaluate two-year safety and effectiveness outcomes with a multidimensional, expandable interbody fusion device (Luna 3D Interbody Fusion System, Benvenue Medical, Inc., Santa Clara, CA) that is delivered through a minimally invasive approach (6-8 mm) that expands in situ to approximate an anterior lumbar interbody fusion footprint of 25 mm diameter.Material and methodsThis was a retrospective, single-center study that evaluated the clinical utility of a multi-expandable interbody cage in patients undergoing posterior or transforaminal lumbar interbody fusion. Key patient-reported outcomes included back pain severity, leg pain severity, and the Oswestry Disability Index (ODI). Radiographic assessments included disc height (anterior, posterior, and average), foraminal height, segmental lordosis, subsidence, implant migration, and pseudarthrosis. Patients were followed at regular intervals over two years postprocedure.ResultsA total of 50 consecutive patients were treated with transforaminal lumbar interbody fusion (TLIF) using the multidimensional expandable implant. Procedural blood loss was minimal (median 200 ml) and the mean hospital stay was 2.1 days. Perioperative complications were reported in three patients and included a dural tear, postoperative ileus, and end-plate violation. All complications were successfully managed conservatively. There were no nerve root injuries or perioperative infections. Over the two-year follow-up period, one case of subsidence and one case of implant migration were noted on radiographic imaging but required no treatment. Comparing the values reported at baseline and two years, the mean ODI score decreased by 61%, back pain severity decreased by 67%, and leg pain severity decreased by 80% (all p<0.001). Comparing radiographic measures from baseline to two years, anterior disc height increased from 7.6 mm to 15.5 mm, posterior disc height increased from 2.9 mm to 10.1 mm, average disc height increased from 5.6 mm to 13.3 mm, foraminal height increased from 12.2 mm to 20.2 mm, and segmental lordosis increased from 6.2 degrees to 14.0 degrees (all changes p<0.001). One case of non-union was observed and the corresponding two-year fusion rate was 98%.ConclusionsThe utilization of a minimally invasive, multidimensional, expandable interbody implant was safe and effective over two years of clinical follow-up. The implant allows the surgeon to re-establish sagittal balance and to provide a larger surface area for fusion as compared to traditional minimally invasive interbody devices.

3D Printed Cage in Patients with Tibiotalocalcaneal Arthrodesis Using a Retrograde Intramedullary Nail: Early Outcomes

Category:Diabetes, Hindfoot, Trauma, salvage procedureIntroduction/Purpose:Segmental bone loss in the hindfoot hinders the chance of successful outcomes. Tibiotalocalcaneal arthrodesis is a reliable option; however, the risk of nonunion is high. Structural graft is needed to fill the gap, but the use of bone grafts are limited by the availability, risk of collapse, and disease transmission. Three-dimensional (3D) printed titanium implants offer a strong scaffold that can be customized and present similar healing rates. The purpose of the study was to describe the clinical outcomes and the radiologic union rate of a case series of patients with hindfoot arthrodesis, using a retrograde intramedullary nail associated to a 3D printed titanium cage.Methods:After obtaining approval from our institution review board, a retrospective chart review was performed on seven patients undergoing hindfoot arthrodesis, using a retrograde intramedullary nail associated to a custom 3D printed titanium cage from March 2015 to December 2017. Demographic and clinical data were collected. Functional outcomes were assessed using The American Orthopedic Foot and Ankle Score (AOFAS) and the Visual Analog Scale (VAS) for pain. Hindfoot alignment was evaluated using preoperative and postoperative weightbearing radiographs that included anteroposterior, lateral and Saltzman views. Radiographic union was assessed using computed tomography scan at 6 and 12 months postoperatively.Results:All patients had ankle arthritis and six of them (85%) had prior surgery in the compromised hindfoot. The average age at TTC fusion was 57 (range, 29 to 71) years. The mean follow-up time was 21 (range, 12 to 32) months. Six patients had a healed fusion and one patient underwent below knee amputation due to recurrence of chronic osteomyelitis in the ankle. Two additional patients had minor complications. The average AOFAS at pre-op was 35 (range, 20 to 42) points as compared to 68 (range, 53 to 78) points at final follow-up; P=0.004. Preoperative VAS pain was 80.4 (range, 70 to 85) points as compared to 26.8 (range, 6 to 60) points; P=0.002.Conclusion:Tibiotalocalcaneal arthrodesis using customized titanium cages for patients with large bone defects has shown a high rate of union in those at high risk of nonunion. Further research is needed to monitor the development of late complications.

Early versus delayed corpectomy in thoracic and lumbar spine trauma. A long-term clinical and radiological retrospective study

Summary and background dataMany authors have demonstrated the necessity of reconstruction of the anterior column in spinal trauma with vertebral body collapse or nonunion. There is no publication comparing the result depending on the time between trauma and anterior reconstruction of the vertebral body. ObjectiveTo compare long-term clinical and radiological results between early and late anterior vertebral body reconstruction with expandable cages in patients with thoracic and lumbar spine trauma. HypothesisAn early anterior reconstruction of thoracolumbar fractures provides better clinical and radiological outcomes than a delayed one. Materials and methodsA retrospective clinical study was carried out with 44 consecutive patients with injuries of the thoracic and lumbar spine treated operatively with combined posterior stabilization and anterior reconstruction with an expandable implant for vertebral body replacement. All patients were evaluated with EOS full-spine radiograph and CT-scan. The mean follow-up was 5.1 years. Clinical result was evaluated with ODI, SF12, VAS back pain, return to work and sport. Radiological result was evaluated with regional kyphosis angle (RKA) evolution, fusion rate and sagittal alignment. In Group A, twenty-nine patients underwent an early anterior reconstruction within 3 weeks after trauma. The indication of vertebral body reconstruction was placed after post-operative CT-scan for a Mc Cormack score≥7. In Group B, fifteen patients underwent a late anterior reconstruction after diagnosis of nonunion by the combination of pain and CT-scan after 1 year. ResultsClinical scores and scales were significantly better for patients operated early in Group A. Return to work and activities were significantly more important in Group A too. The mean RKA correction with posterior reduction was 9.3°. The secondary anterior approach permit to reduce 2.9° more. At last follow-up, the loss of reduction was 4.3°. There was no significant difference between groups for those results. No difference in fusion rate was observed between groups. There was no significant difference between groups in the sagittal alignment excepted for SVA that was higher for Group B while remaining under a normal value of 50mm. ConclusionEarly anterior vertebral body reconstruction for fractures gives better clinical results than delayed reconstruction for patients with diagnosis of nonunion in patients with thoracic and lumbar spine trauma. Moreover, the shorter the time from trauma to operation, the better the sagittal reduction of kyphosis. The use of expandable titanium cage is a good way to perform and maintain this reduction. Level of evidenceIV, retrospective study.

Стабилизация грудинно-реберного комплекса при обширных флотирующих переломах ребер у детей: обзор литературы и собственный опыт

Thoracic injury is the leading cause of fatal complications. The incidence of chest trauma remains high. There are many fixation methods of the floating ribs of thoracic cage, which are technically challenging and linked to various materials. Objective: to search options for the sternocostal complex stabilization without the expenditures for manufacturing customised devices; to describe and implement the rib cage fixation method for floating fractured ribs in severely injured children, which is used by paediatric surgeons in Tyumen. Material and methods. In the south of the Tyumen Region for the period of 2016–2018, an original method of fixing the thoracic cage with multiple floating fractured ribs by means of a V-shaped modelled Cramer’s wire splint to extend the area of contact with the rib cage was used in four patients aged from 9 to 17 years. The splint was sutured with non-absorbable threads to the edges of stable parts of the ribs and to unstable segment of the rib cage, followed by its external fixation. Results. Having applied this method, it was possible to reliably, minimally invasively stabilize the rib cage in patients, achieve early spontaneous breathing, which reduced the length of stay in the intensive care unit. No purulent septic complications were observed. Conclusions. The proposed restoration method of skeletal function of the chest by using the external fixation with a V-shaped Cramer’s wire splint is simple and acceptable in any hospital.

A comparison of long-term outcomes of nanohydroxyapatite/polyamide-66 cage and titanium mesh cage in anterior cervical corpectomy and fusion: A clinical follow-up study of least 8 years

ObjectivesThe nanohydroxyapatite/polyamide-66 (n-HA/PA66) cage is a novel biomimetic nonmetal cage device that is now used in some medical centers, while the titanium mesh cage (TMC) is a typical metal cage device that has been widely used for decades. This study was performed to compare the long-term outcomes of these two different cages in patients undergoing anterior cervical corpectomy. Patients and methodsThis retrospective study involved 107 patients who underwent single-level anterior corpectomy using either a TMC (n = 52) or an n-HA/PA66 cage (n = 55) for treatment of cervical degenerative disease with a minimum follow-up of 8 years. Their radiographic data (cage subsidence, fusion status, segmental sagittal alignment, and cervical spine degeneration) and clinical data [visual analog scale (VAS) and Japanese Orthopedic Association (JOA) scores] were evaluated preoperatively, postoperatively, and at the final follow-up. ResultsThe mean duration of follow-up was 103.6 ± 6.3 months in the n-HA/PA66 group and 102.4 ± 4.6 months in the TMC group. The n-HA/PA66 group and the TMC group had similar final fusion rates (97% vs. 94%, respectively). The final n-HA/PA66 cage subsidence was 2.4 ± 1.0 mm with 18.2% subsidence of >3 mm, which was significantly lower than the respective 3.0 ± 0.7 mm and 40.4% for the TMC (p < 0.01). The n-HA/PA66 group also had better JOA scores than the TMC group (p < 0.01). No significant difference in the segmental sagittal alignment, cervical lordosis, or VAS score was observed between the two groups (p = 0.18, 0.42, and 0.17, respectively). ConclusionsThe n-HA/PA66 cage is associated with excellent radiographic fusion, lower subsidence and better clinical outcomes than the TMC within 8 years after single-level anterior cervical corpectomy. With the addtional benefit of radiolucency, the n-HA/PA66 cage could be superior to the TMC in anterior cervical construction.

Thoracoscopic anterior stabilization for thoracolumbar fractures in patients without spinal cord injury: quality of life and long-term results

PurposeTo determine the health-related quality of life (QOL), safety and radiologic parameters after thoracoscopic treatment of traumatic thoracolumbar fractures using a distractible cage in patients without spinal cord injury (SCI).MethodsRetrospective cohort study of patients treated between 2004 and 2012 in a university level-one trauma center. Patient and treatment characteristics were collected from the hospital information system. All available radiographic material was assessed for fracture characteristics and Cobb angle at consecutive times. Patients completed the SF-36 and EQ-5D QOL questionnaires at follow-up.Results105 patients were treated with a distractible cage, which was performed thoracoscopically in 86 cases, including 16 patients with SCI. Of 70 eligible patients, 46 were available for follow-up and completed the questionnaires at median 49 months after surgery. QOL was lower on most domains compared to the general population. Compared to patients who underwent solely posterior fixation for less severe fractures, QOL did not differ significantly. The complication rate was low (10%) with one re-operation. Mean loss of correction was 6.8° and bony fusion on CT scan was present in 98% of patients. Maintenance of kyphosis correction was significantly better for two segments anterior fixation compared to one segment.ConclusionsThoracoscopic anterior stabilization leads to a high percentage of bony fusion in highly unstable thoracic and thoracolumbar fractures with limited post-operative loss of correction and no hardware failure. QOL of these patients does not return to normal population values but is comparable to that of patients with less severe fractures treated with solely posterior instrumentation.Graphical abstractThese slides can be retrieved under Electronic Supplementary Material.

Overpowering posterior lumbar instrumentation and fusion with hyperlordotic anterior lumbar interbody cages followed by posterior revision: a preliminary feasibility study.

OBJECTIVE The authors' aim in this study was to evaluate whether sagittal plane correction can be obtained from the front by overpowering previous posterior instrumentation and/or fusion with hyperlordotic anterior lumbar interbody fusion (ALIF) cages in patients undergoing revision surgery for degenerative spinal conditions and/or spinal deformities. METHODS The authors report their experience with the application of hyperlordotic cages at 36 lumbar levels for ALIFs in a series of 20 patients who underwent revision spinal surgery at a single institution. Included patients underwent staged front-back procedures: ALIFs with hyperlordotic cages (12°, 20°, and 30°) followed by removal of posterior instrumentation and reinstrumentation from the back. Patients were divided into the following 2 groups depending on the extent of posterior instrumentation and fusion during the second stage: long constructs (≥ 6 levels with extension into thoracic spine and/or pelvis) and short constructs (< 6 levels). Preoperative and postoperative standing radiographs were evaluated to measure segmental lordosis (SL) along with standard sagittal parameters. Radiographic signs of pseudarthrosis at previously fused levels were also sought in all patients. RESULTS The average patient age was 54 years (range 30-66 years). The mean follow-up was 11.5 months (range 5-26 months). The mean SL achieved with 12°, 20°, and 30° cages was 13.1°, 19°, and 22.4°, respectively. The increase in postoperative SL at the respective surgically treated levels for 12°, 20°, and 30° cages that were used to overpower posterior instrumentation/fusion averaged 6.1° (p < 0.05), 12.5° (p < 0.05), and 17.7° (p < 0.05), respectively. No statistically significant difference was found in SL correction at levels in patients who had pseudarthrosis (n = 18) versus those who did not (n = 18). The mean overall lumbar lordosis increased from 44.3° to 59.8° (p < 0.05). In the long-construct group, the mean improvement in sagittal vertical axis was 85.5 mm (range 19-249.3 mm, p < 0.05). Endplate impaction/collapse was noted in 3 of 36 levels (8.3%). The anterior complication rate was 13.3%. No neurological complications or vascular injuries were observed. CONCLUSIONS ALIF in which hyperlordotic cages are used to overpower posterior spinal instrumentation and fusion can be expected to produce an increase in SL of a magnitude that is roughly half of the in-built cage lordotic angle. This technique may be particularly suited for lordosis correction from the front at lumbar levels that have pseudarthrosis from the previous posterior spinal fusion. Meticulous selection of levels for ALIF is crucial for safely and effectively performing this technique.

Cage Retropulsion after Posterior Lumbar Interbody Fusion by Unilateral stand-alone Carbon Cage

Background Data: Posterior lumbar interbody fusion (PLIF) becomes widely used surgical procedure to reduce pain and spinal instability resulting from some spinal diseases. Although this procedure is widely used, postoperative conditions such as good clinical outcome and spinal instability are still a matter of controversy. Maintenance of disc height and solid fusion significantly increased with PLIF with cage. Cage migration to the spinal canal is one of the most common cause of implant failure in mono-segmental lumbar interbody fusion.Purpose: to evaluate the efficacy of unilateral stand-alone carbon cage in patients with degenerated lumbar disc diseaseStudy Design: A prospective follow-up study.Patients and Methods: A prospective follow-up study was carried out on 40 patients (24 males and 16 females). All patients had single level lumbar disc prolapse, diagnosed clinically and radiologically, who admitted to Neurosurgery Department, Mansoura University Hospital and on Private work during the period from March 2013 to March 2015. On admission demographic data as age, gender, job and body mass index (BMI) were obtained for all patients. All patients were examined on admission clinically and radiologically by MRI lumbosacral spine and dynamic study plain x-ray films in extension and flexion views. Disc height was measured for all patients at the herniated level only, by MRI using Dabbs method. The outcome was measured according to modified Mac-Nab’s criteria.Results: Six cases out of 40 (15%) developed cage retropulsion. There was a lower significant mean age (38.3+2.96) for cases with cage retropulsion compared to (42.4+5.7) for those cases without cage retropulsion (P 0.05). The majority of cases with cage retropulsion were obese (66.7%), while those without cage retropulsion were overweight (64.7%). L4-5 was the most common affected level (66.6%) among cases with cage retropulsion, and those without retropulsion were (70.6%). The majority of cases (5) with cage retropulsion (83.3%) had wide disc space height. Workers and carriers represented the majority of cases with cage retropulsion (33.3%). All cases (100%) with cage retropulsion had a poor outcome. However, the majority of cases with no cage retropulsion had excellent (50%) and good (11.8%) outcome according to the modified Mac-Nab’s criteria.Conclusion: Our data suggest that strenuous work, early heavy physical activities, large disc height may be contributing factors for cage retropulsion. Cage retropulsion has a negative impact on patients’ outcome. (2017ESJ146)

Minimally Invasive TLIF Using Unilateral Approach and Single Cage at Single Level in Patients over 65.

Background. Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a widely accepted surgical procedure. But there are only a few reports of MIS-TLIF using the unilateral approach and single cage in elderly patients. Objective. The study investigated the clinical and radiological outcomes of MIS-TLIF using the unilateral approach and single cage in the patients over 65 years of age. Methods. Thirty-eight patients were followed for a mean of 15.5 ± 11.61 months. Radiological data include fusion rate, change of disc height, and central canal area. The numeric rating scale (NRS) and Oswestry disability index (ODI) were used to assess clinical outcomes. Results. The mean age of these patients at operation was 71.82 ± 4.71 years (range, 65–82 years). Evidence of fusion was observed radiologically in 64.71% at 6 months and 87.5% at 12 months after surgery, giving a final fusion rate of 100%. The mean NRS scores for back and leg pain and ODI scores improved significantly at the final follow-up. Conclusions. Clinical and radiologic outcomes of MIS-TLIF using unilateral approach and single cage in elderly patients indicate an acceptable method for the treatment of various kinds of lumbar spinal diseases.

Pyogenic lumbar spondylodiscitis treated with transforaminal lumbar interbody fusion: safety and outcomes.

Our aim was to study the safety and outcomes of posterior instrumentation and transforaminal lumbar interbody fusion (TLIF) for treating pyogenic lumbar spondylodiscitis. Retrospective analysis was performed on prospectively collected data of 27 consecutive cases of lumbar pyogenic spondylodiscitis treated with posterior instrumentation and TLIF between January 2009 and December 2012. Cases were analysed for safety, radiological and clinical outcomes of transforaminal interbody fusion using bone graft ± titanium cages. Interbody metallic cages with bone graft were used in 17 cases and ten cases used only bone graft. Indications for surgical treatment were failed conservative management in 17, neurodeficit in six and significant bony destruction in four. There were no cases reporting cage migration, loosening, pseudoarthrosis or recurrence of infection at a mean follow-up of 30months. Clinical outcomes were assessed using Kirkaldy-Willis criteria, which showed 14 excellent, nine good, three fair and one poor result. Mean focal deformity improved with the use of bone graft ± interbody cages, and the deformity correction was maintained at final follow-up. Mean pre-operative focal lordosis for the graft group was 8.5° (2-16.5°), which improved to 10.9 °(3.3-16°); mean pre-operative focal lordosis in the group treated with cages was 6.7 °(0-15°), which improved to 7°(0-15°) . TLIFs with cages in patients with pyogenic lumbar spondylodiscitis allows for acceptable clearance of infection, satisfactory deformity correction with low incidence of cage migration, loosening and infection recurrence.

The Efficiency of Zero-profile Implant in Anterior Cervical Discectomy Fusion

A prospective controlled study. The aim of this study was to compare the safety and efficacy of the zero-profile device with that of an anterior cervical plate and cage in patients undergoing anterior cervical discectomy and fusion (ACDF). A series of studies have indicated that anterior instruments produce good clinical results during ACDF. However, common implants are associated with a high rate of postoperative complications. A cervical stand-alone cage with integrated fixation for zero-profile segmental stabilization has been developed to solve this problem. A total of 46 patients with cervical radiculopathy or myelopathy were randomly treated with an anterior plate and a cage or a new zero-profile implant between September 2009 and April 2010. Patients were followed for 2 years. The operation time, blood loss, exposure to radiation, the Japan Department of Orthopedics Association (JOA) score, pain Visual Analogue Score (VAS), and dysphagia score were recorded. The operation was completed successfully in 46 patients. Twenty-three patients received an anterior plate and cage (control group) and 23 patients received the new zero-profile implant (test group). Analysis of postoperative data at all protocol-defined intervals demonstrated improvement in all clinical outcomes for both the groups when compared with the corresponding preoperative data. No significant difference in VAS and JOA score was found in the 2 treatment groups. The test group had a greater reduction in dysphagia at all follow-up intervals, compared with the control group. No adjacent segment degeneration was found in the test group, whereas 4 patients in the control group developed degeneration in adjacent segments (P=0.045). Both the groups had no adverse events associated with the implant or implant surgery. The Zero-P implant is a viable alternative to ACDF in patients with persistently symptomatic, single-level cervical disk disease. The procedure requires more technical requirements than traditional plates.

Zero-profile integrated plate and spacer device reduces rate of adjacent-level ossification development and dysphagia compared to ACDF with plating and cage system

Retrospective case-control study. To compare the safety and efficacy of the Zero-profile (Zero-p) integrated plate and spacer device to that of an anterior cervical plate and cage in patients undergoing anterior cervical discectomy and fusion (ACDF). Anterior cervical plating system has provided good results, including higher fusion rate and improved alignment since its use. However, adjacent-level ossification development (ALOD) and dysphagia have been usually reported associating with plates. This was a retrospective control study. Sixty-two patients with cervical radiculopathy or myelopathy were treated with an anterior plate and cage or Zero-p implant between January 2011 and December 2011. The mean follow-up was 33.1months in the plate and cage group and 30.6months in Zero-p group. Patient demographics, operative details and complications were reviewed. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scores and JOA recovery rate before and after operations. Incidence of cephalad and caudal ALOD on the lateral radiographs was studied at preoperation, immediate postoperation and last follow-up. Incidence of dysphagia was also recorded after operation according to Bazaz-Yoo dysphagia index. Thirty-two patients received an anterior plate and cage and 30 received the Zero-p implant. There were no statistical differences in patient demographics, operative details between the two groups. The JOA scores significantly increased compared with preoperational measurements in both groups (p < 0.05), but the JOA recovery rate was similar (72.2% for plate and cage group and 77.0% for Zero-p group, p >0.05). ALOD occurred in 12 (18.8%) of the 64 cephalad and caudal adjacent segments in plate with cage group, and only 1 (1.6%) of 63 adjacent levels (including three noncontiguous cases) presented with ALOD in Zero-p group. The difference was significant (p < 0.01). The incidence of dysphagia in the Zero-p group was lower compared with that in the plate with cage group, and the symptom duration was much shorter (p < 0.01). Both groups had no adverse events associated with the implant or implant surgery. The Zero-profile implant is safe and efficacious after ACDF. It can reduce the rate of adjacent-level ossification development and dysphagia compared to anterior plate and cage.

The SNAP trial: a double blind multi-center randomized controlled trial of a silicon nitride versus a PEEK cage in transforaminal lumbar interbody fusion in patients with symptomatic degenerative lumbar disc disorders: study protocol

BackgroundPolyetheretherketone (PEEK) cages have been widely used in the treatment of lumbar degenerative disc disorders, and show good clinical results. Still, complications such as subsidence and migration of the cage are frequently seen. A lack of osteointegration and fibrous tissues surrounding PEEK cages are held responsible. Ceramic implants made of silicon nitride show better biocompatible and osteoconductive qualities, and therefore are expected to lower complication rates and allow for better fusion.Purpose of this study is to show that fusion with the silicon nitride cage produces non-inferior results in outcome of the Roland Morris Disability Questionnaire at all follow-up time points as compared to the same procedure with PEEK cages.Methods/DesignThis study is designed as a double blind multi-center randomized controlled trial with repeated measures analysis. 100 patients (18–75 years) presenting with symptomatic lumbar degenerative disorders unresponsive to at least 6 months of conservative treatment are included. Patients will be randomly assigned to a PEEK cage or a silicon nitride cage, and will undergo a transforaminal lumbar interbody fusion with pedicle screw fixation. Primary outcome measure is the functional improvement measured by the Roland Morris Disability Questionnaire. Secondary outcome parameters are the VAS leg, VAS back, SF-36, Likert scale, neurological outcome and radiographic assessment of fusion. After 1 year the fusion rate will be measured by radiograms and CT. Follow-up will be continued for 2 years. Patients and clinical observers who will perform the follow-up visits will be blinded for type of cage used during follow-up. Analyses of radiograms and CT will be performed independently by two experienced radiologists.DiscussionIn this study a PEEK cage will be compared with a silicon nitride cage in the treatment of symptomatic degenerative lumbar disc disorders. To our knowledge, this is the first randomized controlled trial in which the silicon nitride cage is compared with the PEEK cage in patients with symptomatic degenerative lumbar disc disorders.Trial registrationNCT01557829

The CASCADE trial: effectiveness of ceramic versus PEEK cages for anterior cervical discectomy with interbody fusion; protocol of a blinded randomized controlled trial

BackgroundAnterior cervical discectomy with interbody fusion cages is considered the standard surgical procedure in patients with cervical disc herniation. However, PEEK or metal cages have some undesirable imaging characteristics, leading to a search for alternative materials not creating artifacts on images; silicon nitride ceramic. Whether patients treated with silicon nitride ceramic cages have similar functional outcome as patients treated with PEEK cages is not known. We present the design of the CASCADE trial on effectiveness of ceramic cages versus PEEK cages in patients with cervical disc herniation and/or osteophytes.Methods/DesignPatients (age 18–75 years) with monoradicular symptoms in one or both arms lasting more than 8 weeks, due to disc herniation and/or osteophytes, are eligible for the trial. The study is designed as a randomized controlled equivalence trial in which patients are blinded to the type of cage for 1 year. The total follow-up period is 2 years. The primary outcome measure is improvement in the Neck and Disability Index (NDI). Secondary outcomes measures include improvement in arm pain and neck pain (VAS), SF-36 and patients' perceived recovery. The final elements of comparison are perioperative statistics including operating time, blood loss, length of hospital stay, and adverse events. Lateral plane films at each follow-up visit and CT scan (at 6 months) will be used to judge fusion and the incidence of subsidence. Based on a power of 90% and assuming 8% loss to follow-up, 100 patients will be randomized into the 2 groups. The first analysis will be conducted when all patients have 1 year of follow-up, and the groups will be followed for 1 additional year to judge stability of outcomes.DiscussionWhile the new ceramic cage has received the CE Mark based on standard compliance and animal studies, a randomized comparative study with the golden standard product will provide more conclusive information for clinicians. Implementation of any new device should only be done after completion of randomized controlled effectiveness trials.

Acetabular revision using an anti-protrusion cage in patients with periprosthetic acetabular bone loss

Objective To investigate the risk factors related to the survival time of anti-protrusion cage in acetabular revision.Methods Data of 40 patients who had received acetabular revision using antiprotrusion cages between January 2002 and June 2010 were retrospectively analyzed.There were 16 males and 24 females,aged from 22 to 77 years (average,60.3 years).All patients were followed up for 12 to 82 months (average,39.2 months).According to the AAOS classification,there were 29 cases of type C and 11 cases of type D； while according to the Paprosky classification,there were 29 cases of type ⅢA and 11 cases of type Ⅲ B.The multiple regression analysis was utilized to investigate the relationships between different factors and anti-protrusion cage failure.The corresponding factors included gender,age,bone loss classification,superior or lateral migration of acetabular center of rotation,abduction angle,fixation manners (simple flange fixation or flange fixation plus transacetabular screw fixation),bone grafting techniques and cup type.Results At final follow-up,the average Harris score was 74.5±15.4.Two patients received rerevision due to prosthetic loosening.Obvious radiological loosening of prosthesis combined with pain was found in 2 cases.The statistical analysis indicated that superior migration of acetabular center of rotation,abduction angle and fixation manners were correlated with cup failure,especially when the superior migration was more than 8.5 mm or the abduction angle was larger than 53.5°.Flange fixation plus transacetabular screw fixation could reduce risk of cup failure.Conclusion There is a higher cup failure risk in acetabular revision using an anti-protrusion cage for patients with serious bone defect.However,implanting cup at the level of the true acetabulum as far as possible,decreasing abduction angle properly and using flange fixation plus transacetabular screw fixation can reduce cup failure risk. Key words: Acetabulum; Arthroplasty, replacement, hip; Reoperation