Surgical treatment of craniocervical instability: comparison of two constructs regarding clinical and radiological outcomes of 100 patients.

PURPOSE: There is an increased demand for surgical solutions to treat craniocervical instability. This retrospective study demonstrates the clinical and radiological outcomes of unstable craniocervical junction treated with occipitocervical fusion. MATERIAL AND METHODS: The mean age of 52 females and 48 males was 56.89 years. The clinical and radiological outcomes were assessed, including NDI, VAS, ASIA score, imaging, complications and bony fusion in two used constructs: a modern occipital plate-rod-screw system (n = 59) and previous bilateral contoured titanium reconstruction plates-screws (n = 41). RESULTS: Clinically and on imaging, patients presented with neck pain, myelopathy, radiculopathy, vascular symptoms and craniocervical instability. The mean follow-up was 6.47 years. A solid bony fusion was achieved in 93.81% of the patients. The NDI and the VAS improved significantly from 28.3 and 7.67 at the presentation to 16.2 and 3.47 at the final follow-up. The anterior and posterior atlantodental interval (AADI and PADI), the clivus canal angle (CCA), the occipitoaxial angle (OC2A) and the posterior occipitocervical angle (POCA) improved significantly. Six patients required early revision. CONCLUSION: Occipitocervical fusion can yield excellent results regarding clinical improvement and long-term stability with a high fusion rate. Simple reconstruction plates, though more demanding surgically, achieve similar results. Preserving a neutral patient's position for fixation avoids postoperative dysphagia and may help prevent adjacent segment disease development.

Cement discoplasty for managing lumbar spine pseudarthrosis in elderly patients: a less invasive alternative approach for failed posterior lumbar spine interbody fusion.

PURPOSE: A retrospective cohort study was performed to evaluate pseudoarthrosis treatment results by injection of cement in disc space of failed fusion in posterior lumbar interbody fusion in patients above 65 years. METHODS: Forty-five patients above 65 years with symptomatic pseudarthrosis after lumbar spine fusion were treated by cement injection in the affected disc space. RESULTS: There were 30 females and 15 males. The mean age at the operation was 74 ± 6.5 years (range 65-89). Discoplasty was performed after the primary fusion operations after a mean of 14 ± 1.3 months (range 12-24). The mean preoperative VAS was 7.5 (range 6-9), and ODI was 36 (range 30-45). Cement injection was done at one level in most of the cases (35 patients). In seven cases, two injection levels were done, and in three cases, three levels. Twenty-three patients had discoplasty only, while 22 had discoplasty and screws change, including 14 cases of extension of the instrumentation. The mean postoperative follow-up was 32 ± 6.5 months. The VAS improved to 3.5 (range 2-5) (p = 0.02) and ODI to 12.3 (range 5-35) (p = 0.001). Reoperation was indicated in two (4%) patients by screws loosening. Asymptomatic cement leakage occurred in the paravertebral space in seven cases (15.5%). CONCLUSION: Cement discoplasty offers a less invasive reliable surgical solution in elderly patients with symptomatic lumbar pseudarthrosis in the elderly patients. In cases with screw loosening, discoplasty should be combined with screw revision.

What constitutes the fat signal detected by MRI in the spine of patients with ankylosing spondylitis? A prospective study based on biopsies obtained during planned spinal osteotomy to correct hyperkyphosis or spinal stenosis.

OBJECTIVE: Study the MRI signal of fatty lesions (FL) by immunohistological analysis of vertebral body biopsies of patients with ankylosing spondylitis (AS) compared with degenerative disc disease (DDD). METHODS: Biopsies obtained during planned surgery from vertebral edges where MRI signals of FL was detected were stained with H&E. Immunofluorescence (IF) staining was performed to quantify osteoblasts and osteoclasts. Bone marrow (BM) composition, grade of cellularity and quantification of cells were analysed on six randomly chosen high-power fields (HPF; 0.125 mm2) at 200-fold magnification per patient by two experienced researchers in a blinded manner. RESULTS: Biopsies of 21 patients with AS and 18 with DDD were analysed. Adipocytes were found in the BM of 19 patients with AS (90.5%) versus 5 with DDD (27.8%) (p<0.001), while inflammatory infiltrates were found in in the BM of 8 patients with AS (38.1%) versus 14 with DDD (77.8%) (p=0.035) and fibrosis in 6 patients with AS (28.6%) versus 4 with DDD (22.2%) (p=n .s.). The most frequently detected cells were adipocytes in AS (43.3%) versus DDD (16.1%, p=0.002) and inflammatory mononuclear cells in DDD (55%) versus AS (11.0%, p=0.001). Using IF staining, there was more osteoblastic than osteoclastic activity (6.9 vs 0.17 cells/HPF) in FL as compared with inflammatory BM (1.3 vs 7.4 cells/HPF), respectively. CONCLUSION: MRI FL correspond to presence of adipocytes, resulting to change of cellular homeostasis towards diminution of osteoclasts in the BM of patients with AS. The cross-talk between the different cell types and osteitis, fat and new bone formation needs further study.

Surgical treatment of type II odontoid fractures in elderly patients: a comparison of anterior odontoid screw fixation and posterior atlantoaxial fusion using the Magerl-Gallie technique.

PURPOSE: This single-centre retrospective study compared anterior odontoid screw fixation and posterior atlantoaxial fusion in the surgical treatment of type II B odontoid fractures according to Grauer in elderly patients. METHODS: Between 1994 and 2014, 133 consecutive patients above 60 years presenting with type II B odontoid fracture were treated surgically in our department. They were divided retrospectively into two groups. Group A included 47 patients in whom anterior odontoid screw fixation was performed. Group B with 86 patients underwent posterior atlantoaxial fusion. The clinical and radiological data were analysed. Any reoperation during the follow-up was recorded and evaluated. RESULTS: The mean age in group A (74.19 years) was significantly less than in group B (78.16 years). The mean operative time in group A (64.5 min) was significantly shorter than in group B (116 min). Again, the mean amount of blood loss in group A (79 ml) was significantly less than in group B (379 ml). The mean postoperative hospital stay was significantly shorter in group A (17.4 days) than in group B (30 days). The mean follow-up was 29.3 months in group A and 32 months in group B. The rate of pseudoarthrosis was significantly higher in group A (25.5%) than in group B (3.5%). Furthermore, the need for revision surgery was significantly increased in group A (23.4%) than in group B (10.47%). CONCLUSIONS: Odontoid screw fixation is a less invasive surgery for type II B odontoid fractures in elderly patients. However, posterior atlantoaxial fusion provides a superior surgical outcome regarding fracture healing and the need for surgical revisions. These slides can be retrieved under Electronic Supplementary Material.

Presentation and management of symptomatic central bone cement embolization.

BACKGROUND CONTEXT: With more cement augmentation procedures done, the occurrence of serious complications is also expected to rise. Symptomatic central cement embolization is a rare but very serious complication. Moreover, the pathophysiology and treatment of intrathoracic cement embolism remain controversial. PURPOSE: In this case series, we are trying to identify various presentations and suggest our emergent management scheme for symptomatic central cement embolization. PATIENT SAMPLE: Retrospective case series of nine patients with symptomatic central cement embolism identified after vertebroplasty with 24 months of follow-up. Level IV. OUTCOME MEASURES: The degree of dyspnea measured by the New York Heart Association (NYHA) score and/or death related to cement embolism induced cardio/respiratory failure at the final follow-up at 24 months. METHODS: The nine patients, eight females, and one male had a mean age of 70.25 years (range 65-78 years) and were operated between January 2004 and December 2014. They had percutaneous vertebroplasty for osteoporotic non-traumatic and malignant vertebral collapse of dorsal and lumbar vertebrae. Post-vertebroplasty dyspnea and stitching chest pain were striking in the nine patients. After exclusion of cardiac ischemia and medical pulmonary causes for dyspnea, we identified radiopaque lesions on the chest X-ray. Further echocardiography and high-resolution chest CT were performed for optimal localization. Emergent heart surgery was performed in two patients: interventional therapy was conducted in one patient, while the remaining six patients were conservatively treated by anticoagulation. The management decision was taken in the setting of an interdisciplinary meeting depending on localization, fragmentation, and clinical status. RESULTS: All patients of this series showed gradual improvement and an uneventful hospital stay. During our 24-month follow-up phase, eight patients showed no subsequent cardiological and/or respiratory symptoms (NYHA I). However, one mortality due to advanced malignancy occurred. Preoperative anemia was the only common intersecting preoperative parameter among these nine patients. CONCLUSIONS: After cement augmentation, close clinical monitoring is mandatory. A chest CT is pivotal in determining the interdisciplinary management approach in view of the availability of necessary expertise, facilities and the location of the cement emboli whether accessible by cardiac or vascular surgical means. The clinical presentation and its timing may vary and the patient may be seen subsequently by other health care providers obligating a wide-spread awareness for this serious entity among health care providers for this age group as spine surgeons, family and emergency room doctors, and institutional or home-care nurses. Most symptomatic central cement emboli may be treated conservatively.

Bone morphogenetic protein 7 and autologous bone graft in revision surgery for non-union after lumbar interbody fusion.

BACKGROUND: Potential adverse and unknown long-term effects as well as additional costs limit the use of BMPs (Bone morphogenetic proteins) in primary fusion procedures. However, the proven osteoinductive properties render BMPs attractive for the attempt to reach fusion of symptomatic non-unions. The aim of this study is to evaluate the fusion rate and potential disadvantages of eptotermin alfa (rhBMP-7) used with autologous bone graft in revision procedures for lumbar pseudoarthrosis. MATERIALS AND METHODS: At our institution, rhBMP-7 has been used to improve fusion rates in revision surgery for symptomatic pseudoarthrosis during the past 10 years. Eighty-four fusion procedures using rhBMP-7 between 08/2003 and 07/2011 were revisions due to symptomatic lumbar pseudoarthrosis. The surgical approach was posterior in three and combined anterior-posterior in 71 patients. Of those, 74 patients had either reached fusion or had follow-up of at least 39.5 months (range 21-80 months) in the case of pseudoarthrosis. These 74 patients have been included in a retrospective follow-up study. RESULTS: In 60 patients (81.1 %) the rhBMP-7 procedure was successful. In 14 patients, pseudoarthrosis persisted or fusion was questionable. Of those patients 12 accounted for persisting L5-S1 non-union. Persisting non-unions were found in 26.7 % of the study after four or more segment instrumentations compared to the 16.9 % after mono-, bi-, or three-segment instrumentation, and in four of 14 patients with spondylodesis of three or more levels above a pseudoarthrotic lumbosacral junction. Adverse effects related to the use of eptotermin alfa were rare in this group with symptomatic ectopic bone formation in one patient. CONCLUSIONS: Using rhBMP-7 with autologous bone graft in revisions for lumbar pseudoarthrosis via an anterior approach is safe and can lead to fusion even under unfavorable biomechanical conditions. However, successful outcome depends on the individual constellation. Treatment of non-unions of the lumbosacral junction remains especially difficult in cases with solid fusions above those pseudoarthrotic levels. LEVEL OF EVIDENCE: 4; retrospective follow-up study.

Adjacent segment infection after surgical treatment of spondylodiscitis.

BACKGROUND: This is the first case series to describe adjacent segment infection (ASI) after surgical treatment of spondylodiscitis (SD). MATERIALS AND METHODS: Patients with SD, spondylitis who were surgically treated between 1994 and 2012 were included. Out of 1187 cases, 23 (1.94 %) returned to our institution (Zentralklinik Bad Berka) with ASI: 10 males, 13 females, with a mean age of 65.1 years and a mean follow-up of 69 months. RESULTS: ASI most commonly involved L3-4 (seven patients), T12-L1 (five) and L2-3 (four). The mean interval between operations of primary infection and ASI was 36.9 months. All cases needed surgical intervention, debridement, reconstruction and fusion with longer instrumentation, with culture and sensitivity-based postoperative antimicrobial therapy. At last follow-up, six patients (26.1 %) were mobilized in a wheelchair with a varying degree of paraplegia (three had pre-existing paralysis). Three patients died within 2 months after the ASI operation (13 %). Excellent outcomes were achieved in five patients, and good in eight. CONCLUSIONS: Adjacent segment infection after surgical treatment of spondylodiscitis is a rare complication (1.94 %). It is associated with multimorbidity and shows a high mortality rate and a high neurological affection rate. Possible explanations are: haematomas of repeated micro-fractures around screw loosening, haematogenous spread, direct inoculation or a combination of these factors. ASI may also lead to proximal junctional kyphosis, as found in this series. We suggest early surgical intervention with anterior debridement, reconstruction and fusion with posterior instrumentation, followed by antimicrobial therapy for 12 weeks. LEVEL OF EVIDENCE: Level IV retrospective uncontrolled case series.

Corpectomy of the fifth lumbar vertebra, a challenging procedure.

STUDY DESIGN: A retrospective study of 25 consecutive cases undergoing L5 corpectomy and reconstruction. SUMMARY OF BACKGROUND DATA: Corpectomy of L5 is a challenging procedure because of the unique biomechanical and anatomic properties of this level. OBJECTIVE: To report the clinical and radiographic outcomes and to stress the technical difficulties encountered with L5 corpectomy, reconstruction of the resulting defect together with posterior stabilization. METHODS: Between 2003 and 2008 25 consecutive cases (13 females and 12 males, mean age 54.5 y) underwent L5 corpectomy, followed by titanium cage implantation and posterior stabilization. The indications for surgery were fracture (44%), bony destruction by tumor (44%), and spondylodiscitis (12%). RESULTS: The mean amount of intraoperative blood loss was 3.4 L. The cage was implanted through a posterior approach in a single patient with lymphoma. In the remaining 24 patients, an expandable cage was implanted through a ventral approach. Intraoperative complications occurred in 2 patients presenting with fracture. This was in the form of injury to the left common iliac vein in one patient and extensive epidural bleeding reaching 10 L in the other patient. Five patients died within 2 years after surgery: 2 of them were presenting with spondylodiscitis and died later due to sepsis, whereas the remaining 3 patients had advanced malignancy. In the remaining 20 patients, the mean follow-up period was 3.4 years. Local recurrence of infection occurred in 1 patient necessitating change of the cage. Recurrence of metastasis occurred in 2 patients; one of them underwent posterior decompression and the other one was treated successfully with local irradiation. CONCLUSIONS: L5 corpectomy is a demanding procedure because of the vascular anatomy at that level. Large amount of blood loss should be expected. In case of complication or recurrence of the pathology, revision surgery is more demanding and necessitates a wide experience.

Thoracoscopically assisted corpectomy and percutaneous transpedicular instrumentation in management of burst thoracic and thoracolumbar fractures.

STUDY DESIGN: This is a prospective observational study. PURPOSE: The aim of this study was to determine whether the combination of thoracoscopically assisted corpectomy with posterior percutaneous transpedicular instrumentation in prone position achieves treatment goals in burst thoracic or thoracolumbar fractures and minimizes the associated morbidities. METHODS: Between December 2007 and December 2008, 26 patients with acute burst spinal fractures were operated upon in our hospital. Those patients underwent posterior percutaneous stabilization plus anterior thoracoscopically assisted corpectomy and fusion in prone position. Clinical and radiological outcomes of these patients were evaluated after a minimum follow-up period of 2 years. The Oswestry Disability Index (ODI) combined with clinical examination was used for clinical evaluation. Plain X-ray in two views was used for the radiological evaluation. RESULTS: The mean operative time was 248 min. The average blood loss was 765 ml. Ten patients had preoperative neurological deficits ranging from Frankel A to D. One patient did not show any neurological improvement at the final follow-up. The mean ODI at final follow-up was about 7. The mean preoperative kyphosis angle was 25.58°, improved to 9.2° postoperatively and to 13.8° at the final follow-up. No cases of implant failure were reported at the final follow-up. CONCLUSIONS: Minimal invasive spinal techniques including thoracoscopic decompression and fusion and short segment posterior percutaneous instrumentation showed good clinical outcomes and can be considered as alternative to open procedures with decreased rates of morbidities in managing burst thoracic and thoracolumbar fractures.

Surgical treatment of sacroiliac joint infection.

BACKGROUND: Sacroiliac joint infection is rare and frequently missed; purpose of this study is to describe the clinical presentations, comorbidities, laboratory and imaging findings, surgical options and outcomes of this rare condition. MATERIALS AND METHODS: We reviewed all cases of surgical treatment of sacroiliac joint infection operated at our institution between January 1994 and December 2011. Twenty-two patients were included: 14 females and 8 males, with mean age of 50 years. The mean follow-up period was 34 months. Twenty-four operations were performed. Coinciding infection was found in 11 cases (50 %). Twelve patients (54.5 %) presented acutely, while ten patients (45.5 %) had chronic infection. RESULTS: Tuberculous infection was diagnosed in 5 cases and nonspecific infection in 13 cases. In four cases, no organism was isolated. Eleven cases were subjected to debridement only, while debridement and arthrodesis was needed in 11 cases. Eight patients had excellent clinical results, five good, three fair and four poor; one patient was lost to follow-up, and one patient died after 2 weeks. The operative technique depended on the course of the infection, bone destruction and general condition of the patient. There was a significant change in C-reactive protein and erythrocyte sedimentation rate preoperatively and 6 weeks postoperatively, while the difference in white blood cell count was nonsignificant. CONCLUSIONS: In acute cases, the primary aim should be to save joint integrity by early debridement, depending on joint destruction and general patient condition. When it is chronic, it is not secure only to debride the joint, which should be fused.

Four-level anterior cervical discectomies and cage-augmented fusion with and without fixation.

PURPOSE: Anterior cervical decompression and fusion is a well-established procedure for the treatment of cervical spinal canal stenosis. In this study, we evaluated the necessity of spinal instrumentation after four-level anterior cervical decompression and cage fusion. METHODS: From January 2006 until August 2008, 25 patients (8 females and 17 males) (mean age 63.9 ± 7.9 years) suffering from spinal stenosis C3-C7 underwent anterior decompression and interbody fusion. The patients were divided into two groups. Four-level discectomy and cage fusion was performed in all patients. In group A including nine patients, posterior instrumentation with a lateral mass screw-rod system was added, while in group B including 16 patients, additional instrumentation was not performed. The mean duration of follow-up was 48.6 months (average 25-67 months). RESULTS: Clinically, the mean value for the Neck Disability Index improved from 40 ± 23.25 at presentation to 16.31 ± 15.09 at the final follow-up. The difference between the two groups was statistically not significant. Radiologically, the criteria for solid bony fusion were achieved successfully in all patients of group A, and in 87.5 % of patients in group B. The difference between the two groups was statistically not significant. The fused segment was then evaluated in the sagittal radiographs as regards the height and the lordosis angle. The loss in the height as well as the loss in the lordosis angle was more when posterior instrumentation was not added. However, the difference between the two groups was not statistically significant. CONCLUSION: Stand-alone intersomatic cage fusion is an acceptable line of treatment for four-level cervical disc disease, both clinically and radiologically. Although the addition of posterior instrumentation yields better radiological results, the difference does not reach the statistical significance level.

Results of Four-Level Anterior Cervical Discectomy and Fusion Using Stand-Alone Interbody Titanium Cages.

STUDY DESIGN: This is a retrospective study with a minimum follow-up of 2 years. PURPOSE: The aim of this study is to assess the long-term outcomes after performing the four-level anterior cervical discectomy and fusion (ACDF) in the treatment of degenerative cervical spine disease using stand-alone titanium cages. OVERVIEW OF LITERATURE: Over the last decades, a rapid increase in the use of stand-alone cages for ACDF has been observed. However, research on their application in the treatment of four-level diseases is insufficient. METHODS: In this study, 130 patients presenting with symptomatic cervical spondylosis who underwent four-level ACDF using standalone cages in our institution between 2008 and 2016 were assessed. Fifty-two patients were women and 78 men with a mean age of 60.5 years. Their clinical and radiological outcomes were assessed. The results of the Neck Disability Index (NDI) and Visual Analog Scale as well as bony fusion were evaluated, and the revisions were analyzed. All of the patients underwent the four-level microscopic ACDF using the same titanium rectangular cage. RESULTS: The mean follow-up was 47±11.4 months. A fusion of all four levels was achieved in 80.72% of the patients. In 25 patients (19.23%), an incomplete bony bridging was observed in at least one fusion level at the final follow-up. However, only two patients (1.5%) were symptomatic and underwent revision. The mean NDI improved significantly from 39.4±9.3 at presentation to 8.3±6.6 at the final follow-up. Cervical lordosis improved significantly from a mean of 5.5° preoperatively to a mean of 15° postoperatively. Cage sinking and loss of segment height during healing had a mean of 3 mm. CONCLUSIONS: Overall, the application of four-level ACDF using titanium cages in a stand-alone technique has been proven to be a safe and effective treatment method for degenerative disease. In a large cohort, a high rate of good long-term clinical and radiological results was achieved.

Evaluation of Spinal Fusion in Thoracic and Thoracolumbar Spine on Standard X-Rays: A New Grading System for Spinal Interbody Fusion.

STUDY DESIGN: Retrospective evaluation of prospectively collected data. OBJECTIVE: Analyzing time course and stages of interbody fusion of a uniformly operated cohort, defining a grading system and establishing diagnosis-dependent periods of bone healing. METHODS: Sequential lateral radiographs of 238 patients (313 levels) with interbody fusion operated thoracoscopically were analyzed. RESULTS: Evaluation of 1696 radiographs with a mean follow-up of 65.19 months and average numbers of 5.42 (2-18) images per level was performed. Diagnoses were Pyogenic Spondylitis (74), Fracture (96), Ankylosing Spondylitis (38) and Degenerative Disease (105). No case with Grade 2 deteriorated to Grade 5. On average, Grade 4 persisted for 113 days, Grade 3 for 197 days, Grade 2 for 286 days and Grade 1 for 316 days. The first 95% of levels ("Green Zone", ≤ Grade 2) fused at 1 year, the remaining 4% levels fused between 12 and 17 months ("Yellow Zone") and the last 1% ("Red Zone") fused after 510 days. CONCLUSION: Sequential lateral radiographs permit evaluation of interbody fusion. Grade 2 is the threshold point for fusion; once accomplished, failure is unlikely. If fusion (Grade 2,1 or 0) is not reached within 510 days, it should be regarded as failed. The 510-day-threshold could reduce the necessity of CT scanning for assessing fusion.

Management of Symptomatic Cervical Spine Pseudarthrosis: A Suggested Algorithm for Surgical Planning.

BACKGROUND: The clinical outcome of anterior cervical decompression and fusion (ACDF) correlates with fusion rates. There is a debate about how patients with symptomatic pseudarthrosis should be managed. In this study, a treatment plan is developed based on the surgical results of 95 patients and the recent literature. METHODS: A retrospective study to evaluate the long-term results after surgical treatment of symptomatic pseudarthrosis after ACDF. Between 1994 and 2015, 95 patients underwent surgery due to symptomatic pseudarthrosis after ACDF. The diagnosis was confirmed with dynamic radiographs and computed tomography scans. The approach used was anterior in 62 (65.1%), posterior in 13 (13.7%), and combined anterior and posterior in 20 (21.2%) patients. The operative details and the radiological and clinical results were analyzed. RESULTS: The primary operation was fusion using cages in 70, bone graft and plate in 16, and bone graft only in 9 patients. The revision was performed after a mean of 27 months. After a mean follow-up of 52 months, the mean Visual Analog Scale improved from 7.5 to 2.3 (P = 0.001), and the mean Neck Disability index improved from 26.4 to 8.7 (P = 0.034). Fusion was achieved in all patients after a mean of 7.8 (SD 2.9) months. Reoperation was indicated in 4 patients, all of whom were in the anterior-only group, and was due to retropharyngeal hematoma in 1 patient and cage sinking with kyphosis in 3 patients. CONCLUSIONS: Solid arthrodesis significantly improves the symptoms of cervical pseudarthrosis patients. The presence of adjacent segment disease, implant migration, residual stenosis, and segmental kyphosis plays an important role in decision-making. A treatment recommendation plan has been suggested. LEVEL OF EVIDENCE: 4.

Convolutional neural network-based automated segmentation and labeling of the lumbar spine X-ray.

PURPOSE: This study investigated the segmentation metrics of different segmentation networks trained on 730 manually annotated lateral lumbar spine X-rays to test the generalization ability and robustness which are the basis of clinical decision support algorithms. METHODS: Instance segmentation networks were compared to semantic segmentation networks based on different metrics. The study cohort comprised diseased spines and postoperative images with metallic implants. RESULTS: However, the pixel accuracies and intersection over union are similarly high for the best performing instance and semantic segmentation models; the observed vertebral recognition rates of the instance segmentation models statistically significantly outperform the semantic models' recognition rates. CONCLUSION: The results of the instance segmentation models on lumbar spine X-ray perform superior to semantic segmentation models in the recognition rates even by images of severe diseased spines by allowing the segmentation of overlapping vertebrae, in contrary to the semantic models where such differentiation cannot be performed due to the fused binary mask of the overlapping instances. These models can be incorporated into further clinical decision support pipelines.

Symptomatic Intracranial Hemorrhage after Dural Tear in Spinal Surgery-A Series of 10 Cases and Review of the Literature.

OBJECTIVE: Intracranial hemorrhage (IH) after spinal surgery is a rare but potentially life-threatening complication. Knowledge of predisposing factors and typical clinical signs is essential for early recognition, helping to prevent an unfavorable outcome. METHODS: A retrospective analysis was performed of patients with IH after spinal surgery treated in our institution between 2012 and 2018. The literature dealing with IH complicating spinal surgery was reviewed. RESULTS: Our investigation found 10 patients with IH (6 female and 4 male). To the best of our knowledge, this is the largest series reported so far. The assumable incidence of IH after spinal surgery in our population was 0.0657%. Durotomy was noticed in 6 patients, all of whom were treated according to a local standard protocol. In 4 patients, the dural tear was occult. Hemorrhage occurred mostly in the cerebellar compartment. Eight of 10 patients had long-standing arterial hypertension, which seems to be a risk factor (hazard ratio, 1.58). Five patients were treated conservatively, whereas 3 required a cerebrospinal fluid (CSF) diversion procedure. In 2 patients, revision surgery with duraplasty was necessary. Seven patients were discharged with little to no neurologic symptoms, and 3 had significant deterioration. One patient died because of brainstem herniation. Review of the literature identified 54 articles with 72 patients with IH complicating spinal surgery. CONCLUSIONS: Patients with intraoperative CSF loss should be kept under close supervision postoperatively. After opening of the dura, a watertight closure should be attempted. The use of subfascial suction drainage in cases of a dural tear as well as preexistent arterial hypertension seems to be a risk factor for the development of IH. Intracranial bleeding must be considered in every patient with unexplained neurologic deterioration after spinal surgery and should be ruled out by cranial imaging. To ensure early recognition and prevent an unfavorable outcome, a high index of suspicion is required, especially in revision spinal surgery. The treatment is specific to the extent and location of the IH, thus dictating the outcome. In most patients, conservative treatment led to a good outcome. CSF diversion measures may be necessary in patients with compression or obstruction of the fourth ventricle. Large hematomas with mass effect may require decompressive surgery.

Haematogenous Spondylodiscitis in Patients With Liver Cirrhosis: Case Series of 36 Patients.

STUDY DESIGN: A retrospective study of 36 liver cirrhosis patients presenting with spondylodiscitis. OBJECTIVES: The aim of this study was to analyze the characteristics of spondylodiscitis in the presence of liver cirrhosis and furthermore, to evaluate the outcome of surgery in this specific group of patients. SUMMARY OF BACKGROUND DATA: The incidence of haematogenous spondylodiscitis is increasing. The coexistence of liver cirrhosis makes the course of the disease more aggressive. METHODS: A total of 36 liver cirrhosis patients presented with haematogenous spondylodiscitis. The onset of infection, clinical course and outcomes of management were reviewed retrospectively. RESULTS: The associated comorbidities were cardiac in 17 patients, diabetes in 19, renal insufficiency in 16, and another focus for infection in nine cases. Neurological deficits were found in 24 patients (67%) and fever in 15 cases. Nine patients had septic manifestations. The lumbar spine was affected in 25 patients (69%). Noncontiguous spinal infection was found in nine patients (25%) and epidural abscess in 24 individuals. The preoperative C-reactive protein was elevated in all cases. The causative organism was most commonly Staphylococcus aureus (17 patients). A combined anteroposterior approach was necessary in 28 patients and a minimallly invasive surgery was performed in 30 cases. In-hospital mortality was 14% (5 patients). The neurological improvement rate was 82%. The postoperative antibiotic therapy was taken for more than 8 weeks in 22 patients. In 15 patients, a combination of antibiotics was necessary. CONCLUSION: Spinal infection in the presence of liver cirrhosis is challenging. The rate epidural abscess formation is relatively high. Early diagnosis remains the main cornerstone in the management and the indication for surgery should be carefully considered. Minimally invasive techniques should be used when possible to minimize complication rate, and higher amounts of intraoperative blood loss should be expected. LEVEL OF EVIDENCE: 4.

Vertebral Body Replacement With an Anchored Expandable Titanium Cage in the Cervical Spine: A Clinical and Radiological Evaluation.

BACKGROUND: Expandable cervical cages have been used successfully to reconstruct the anterior spinal column. OBJECTIVE: To perform clinical and radiological evaluation of vertebral body replacement with an anchored expandable titanium cage in the cervical spine after single-level and 2-level corpectomies. METHODS: Between 2011 and 2017, 40 patients underwent a single-level (N = 32) or 2-level (N = 8) anterior corpectomy and fusion using an anchored expandable vertebral body replacement cage. Clinical and radiological data at admission, postoperatively, and at 3- and 12-mo follow-up were retrospectively analyzed. Clinical assessment was performed via standardized neurological evaluation, Odom score, and McCormick classification. Radiological assessment was performed via evaluation of sagittal profile, postoperative position, fusion, and subsidence rates. RESULTS: Mean last follow-up was 14.8 ± 7 mo. Overall clinical and myelopathy-related improvements were shown directly after operation and at last follow-up. A stable centralized positioning of cages was achieved in 37 patients (93%). A mild ventral (>1.5 mm) malplacement was noted in 3 patients (7%) without clinical consequences. Sagittal alignment and preoperative cervical kyphosis improved significantly (7.8° gain of lordosis) and remained stable. Mean preoperative height of operated segments increased by 10 mm postoperatively and remained stable. Fusion rate in non-neoplastic patients and subsidence rate at last follow-up comprised 87.5% and 17.8%. With exception of 1 patient suffering from severe osteoporosis and cage subsidence, no patient needed additional secondary stabilization. CONCLUSION: Anterior corpectomy and fusion by an expandable anchored titanium cage with anchor screws without additional instrumentation resulted in overall clinical improvement and radiological anterior column support, achieving significant and reliable restoration of the physiological sagittal cervical profile.

Reconstruction of large defects in vertebral osteomyelitis with expandable titanium cages.

The purpose of this study was to investigate the outcome of expandable titanium cage implantation in large defects caused by acute vertebral osteomyelitis. Twenty-five patients with acute single or multilevel spondylodiscitis were treated after radical débridement and posterior instrumentation with an anterior expandable titanium cage and bone grafting. Clinical, laboratory and radiological follow-up continued for 36 months. Within the postoperative course there was no recurrence of spinal infection. The final radiological examination showed successful fusion in all cases without implant loosening or failure. At the final follow-up after 36 months the Oswestry Disability Index was 23 +/- 14 and the pain visual analogue scale 2.1 +/- 1.7. This study reveals healing and improved function after expandable titanium cage implantation in all patients. Prerequisites for optimal healing include radical débridement, provision of stability for weight-bearing, adequate bone grafting and correction of deformity using rigid implants.

Reoperation rate after anterior cervical discectomy and fusion using standalone cages in degenerative disease: a study of 2,078 cases.

BACKGROUND CONTEXT: Over the last two decades, there has been a rapid increase in the use of cervical spine interbody fusion cages. Reoperation rate remains an important determinant of procedural efficacy and safety. PURPOSE: To evaluate the rate and reasons for reoperations in cervical spondylosis patients undergoing anterior decompression and fusion using stand-alone cervical interbody fusion cages. STUDY DESIGN: A retrospective study of 2,078 consecutive cases of degenerative cervical spine disease undergoing fusion using stand-alone cages. PATIENT SAMPLE: Between January 2005 and December 2014, 2,078 patients underwent anterior cervical decompression and fusion using stand-alone cages in our institution. OUTCOME MEASURES: The reoperations were analyzed and classified into early (during the first 90 days postoperatively) and late (after 90 days) reoperations. The rate and the causes of reoperation in both groups were reported and the results were compared. METHODS: In 1,558 patients, a short segment fusion (≤2 levels) was performed, while the remaining 520 patients underwent a long segment fusion (≥3 levels). RESULTS: The overall incidence of reoperation was 5.63%. The rate of early reoperations was 2.07%, mostly due to postoperative hematoma, and the rate of late reoperations was 3.56%, mostly due to adjacent segment disease. Revision due to pseudarthrosis was performed in 0.58% of cases. The early reoperation rate was significantly higher in the group with a long segment fusion, while the late reoperation rate was significantly higher in patients undergoing a short segment fusion. CONCLUSION: Following anterior cervical decompression and fusion with a stand-alone cage, the overall incidence of symptomatic pseudarthrosis is low. Patients undergoing long segment fusion should be closely observed in the early postoperative period as they have a higher early complication rate. On the other hand, long segment fusions have a lower incidence of adjacent segment disease over the years.