A new etiology of nontraumatic C0-C1-C2-Complex instability - abnormality of musculus rectus capitis posterior minor: a case report

PURPOSE

This study presents an abnormality of the musculus rectus capitis posterior minor (RCPmi) as a new etiological factor for nontraumatic sagittal plane instability in the C0-C1-C2-complex, with a focus on identifying the absence or atrophy of RCPmi on both sides.

METHODS

A 36-year-old male patient presented with recurring neck pain (VAS 8/10) and tingling paresthesia in the entire left hand over a six-month period, without significant neurological deficits. Radiated arm pain was not reported. Imaging examinations revealed sagittal plane instability in the C0-C1-C2-complex, spinal canal stenosis (SCS), and myelopathy at the C1 level. Subsequently, a dorsal C0-1 reposition and fusion with laminectomy were performed.

RESULTS

The congenital absence or atrophy of RCPmi, leading to the lack of cephalad-rearward traction on the C1-tuberculum-posterius, induced a developmental failure of the C1 posterior arch. Consequently, the oblate-shaped C1 posterior arch lost support from the underlying C2 posterior arch and the necessary cephalad-rearward traction throughout the patient's 36-year life. This gradual loss of support and traction caused the C1 posterior arch to shift gradually to the anterior side of the C2 posterior arch, resulting in a rotational subluxation centered on the C0/1 joints in the sagittal plane. Ultimately, this led to SCS and myelopathy. Traumatic factors were ruled out from birth to the present, and typical degenerative changes were not found in the upper cervical spine, neck muscles, and ligaments.

CONCLUSION

In this case, we not only report the atrophy or absence of RCPmi as a new etiological factor for nontraumatic sagittal plane instability in the C0-C1-C2-complex but also discovered a new function of RCPmi. The cephalad-rearward traction exerted by RCPmi on the C1 posterior arch is essential for the development of a normal C1 anterior-posterior diameter.

Regional Spondylodiscitis Disparities: Impact on Pathogen Spectrum and Patients

Background: Spondylodiscitis is an infectious disease affecting an intervertebral disc and the adjacent vertebral bodies and is often the complication of a distant focus of infection. This study aims to ascertain the regional and hospital-specific disparities in bacterial patterns and resistance profiles in spontaneous and iatrogenic spondylodiscitis and their implications for patient treatment. Methods: We enrolled patients from two German hospitals, specifically comparing a university hospital (UVH) with a peripheral non-university hospital (NUH). We documented patient demographics, laboratory results, and surgical interventions. Microbiological assessments, antibiotic regimens, treatment durations, and resistance profiles were recorded. Results: This study included 135 patients. Upon admission, 92.4% reported pain, with 16.2% also presenting neurological deficits. The primary microbial species identified in both the UVH and NUH cohorts were S. aureus (37.3% vs. 31.3%) and cog. neg. staphylococci (28.8% vs. 34.4%), respectively. Notably, a higher prevalence of resistant bacteria was noted in the UVH group (p < 0.001). Additionally, concomitant malignancies were significantly more prevalent in the UVH cohort. Conclusion: Significant regional variations exist in bacterial prevalence and resistance profiles. Consequently, treatment protocols need to consider these nuances and undergo regular critical evaluation. Moreover, patients with concurrent malignancies face an elevated risk of spondylodiscitis.

A Combined Cyto- and Histopathological Diagnostic Approach Reduces Time to Diagnosis and Time to Therapy in First Manifestation of Metastatic Spinal Disease: A Cohort Study

Malignant spinal lesions (MSLs) are frequently the first manifestation of malignant disease. Spinal care, diagnostic evaluation, and the initiation of systemic therapy are crucial for outcomes in patients (pts) with advanced cancer. However, histopathology (HP) may be time consuming. The additional evaluation of spinal lesions using cytopathology (CP) has the potential to reduce the time to diagnosis (TTD) and time to therapy (TTT). CP and HP specimens from spinal lesions were evaluated in parallel in 61 pts (CP/HP group). Furthermore, 139 pts in whom only HP was performed were analyzed (HP group). We analyzed the TTD of CP and HP within the CP/HP group. Furthermore, we compared the TTD and TTT between the groups. The mean TTD in CP was 1.7 ± 1.7 days (d) and 8.4 ± 3.6 d in HP (p < 0.001). In 13 pts in the CP/HP group (24.1%), specific therapy was initiated based on the CP findings in combination with imaging and biomarker results before completion of HP. The mean TTT in the CP/HP group was 21.0 ± 15.8 d and was significantly shorter compared to the HP group (28.6 ± 23.3 d) (p = 0.034). Concurrent CP for MSLs significantly reduces the TTD and TTT. As a result, incorporating concurrent CP for analyzing spinal lesions suspected of malignancy might have the potential to enhance pts' quality of life and prognosis in advanced cancer. Therefore, we recommend implementing CP as a standard procedure for the evaluation of MSLs.

Traumatic lumbar disc herniation: A systemic case review and meta-analysis

Introduction

Traumatic lumbar disc herniation (TLDH) without fracture in the in-situ motion segment is a rare occurrence compared with degenerative herniation.

Research question

This study provides a systematic discussion of various aspects related to the diagnosis of TLDH.

Material and methods

This review includes 12 cases of TLDH with MR-images since 2009 published in the PubMed and one adjunct illustration. The cases were categorized into two groups for a comprehensive analysis, TLDH with or without in-situ segment fracture. Additionally, we reported a case of a 43-year-old female patient with a recent stenosing TLDH at L5/S1, accompanied by a large sequestration (disc herniation stage-4, and Michigan State University Classification: MSU 3-AB) and an endplate compression fracture at L2 (AO A1).

Results

Isolated traumatic lumbar disc herniation is possible, but it is required exclude cases with fractures in the in-situ motion segment.

Discussion and conclusion

Trauma with related injury mechanisms is the highest priority for the diagnosis of TLDH. Low-grade disc degeneration without significant instability could be accepted for diagnosing TLDH. A TLDH on MR images might show a slightly lower T2-signal compared to the CSF and a homogeneous T1-signal like the spinal cord, as well as a similar STIR-signal of the sequestration and CSF. If necessary, a histological examination could be performed to evaluate the degenerative changes in the injured disc, especially to assist the evaluation due to legal reasons.

The added value of a commercial 16S/18S-PCR assay (UMD-SelectNA, Molzym) for microbiological diagnosis of spondylodiscitis: an observational study

In spondylodiscitis, pathogen identification is important to guide therapy strategies. Here the use of an rDNA PCR assay (Molzym UMDSelectNA) for pathogen detection in spondylodiscitis was evaluated in 182 specimens from 124 spondylodiscitis patients. In 81% of specimens rDNA PCR and conventional culture produced concordant results. Compared to conventional culture, sensitivity and specificity of rDNA PCR were 75% and 83.9%, respectively. The rDNA PCR performed better than conventional culture in identification of Streptococcus spp.. However, overall sensitivity was suboptimal, e.g., in cases with low bacterial burden, and only 5 of 124 patients (4%) received a microbiological diagnosis by employing rDNA PCR. Thus, the added value of routine use of rDNA PCR on spondylodiscitis specimens is limited. Targeted use of the assay in culture-negative cases may be efficient and moderately increase diagnostic yield. The need for susceptibility information implies that 16S rDNA PCR may only be used as an add-on tool to culture.

Meningitis and spondylodiscitis due to Nocardia nova in an immunocompetent patient

BACKGROUND

Disseminated nocardiosis is a very rare disease. By now only few cases of meningitis and spondylodiscitis have been reported. To our knowledge, this is the first case of meningitis caused by Nocardia nova.

CASE PRESENTATION

We report on a case of bacteraemia, meningitis and spondylodiscitis caused by N. nova in an immunocompetent patient. We describe the long, difficult path to diagnosis, which took two months, including all diagnostic pitfalls. After nocardiosis was diagnosed, intravenous antibiotic therapy with ceftriaxone, later switched to imipenem/cilastatin and amikacin, led to rapid clinical improvement. Intravenous therapy was followed by oral consolidation with co-trimoxazole for 9 months without any relapse within 4 years.

CONCLUSIONS

Establishing a diagnosis of nocardiosis is a precondition for successful antibiotic therapy. This requires close communication between clinicians and laboratory staff about the suspicion of nocardiosis, than leading to prolonged cultures and specific laboratory methods, e.g. identification by 16S rDNA PCR.

The limitations of fully threaded screws in isolated percutaneous transarticular screw fixation of C1/C2

Demographic aging accompanied by increased falls inevitably leads to an increased incidence of atlantoaxial instabilities (AAI). Minimally invasive surgical procedures decrease the perioperative risk and regarding the treatment of AAI, percutaneous transarticular screw fixation of C1/C2 was more frequently considered in the past. This study aims to investigate the outcome of patients treated for AAI by isolated percutaneous transarticular screw fixation of C1/C2 (IPTSFC1/C2) using 3.5 mm fully threaded screws to identify its chances and limitations. In this retrospective study, data from patients who underwent IPTSFC1/C2 were analyzed. 23 patients (17 females and 6 males) with an average age of 73.1 years (y) were included. Mean VAS decreased significantly from preoperative 3.9 ± 1.8 to the last follow-up 2.6 ± 2.5 (p = 0.020) and neurological functions were preserved. In the radiological follow-up, we saw a single malposition of an inserted screw (2.27%) and one single bony fusion (4.54%). However, in 6 of 7 patients (85.71%), there was a loosening of the inserted screws due course. We demonstrated that the use of 3.5 mm fully threaded screws for IPTSFC1/C2 results in low rates of osseous fusions between C1 and C2. Therefore, their use in IPTSFC1/C2 is not suitable, especially for geriatric patients with impaired bone status.

Outcome after Posterior Vertebral Column Resection in Patients with Severe Osteoporotic Fractures—A Retrospective Analysis from Two Centers

Background and Objectives: In osteoporotic fractures of the spine with resulting kyphosis and threatening compression of neural structures, therapeutic decisions are difficult. The posterior vertebral column resection (pVCR) has been described by different authors as a surgical treatment in a single-stage posterior procedure. The aim of this study is to evaluate midterm outcomes of patients treated by pVCR due to severe osteoporotic fractures. Materials and Methods: Retrospective data analysis of all the patients treated for osteoporotic fractures by pVCR from 2012–2020 at two centers was performed. Demographic data, visual analog scale (VAS), Frankel scale (FS), Karnofsky performance status (KPS), radiological result and spinal fusion rates were evaluated. Results: A total of 17 patients were included. The mean age was 70 ± 10.2 y. The mean VAS decreased significantly from 7.7 ± 2.8 preoperatively to 3.0 ± 1.6 at last follow-up (p < 0.001) and the segmental kyphosis decreased from 29.4 ± 14.1° to 7.9 ± 8.0° (p < 0.001). The neurologic function on the FS did not worsen in any and improved in four of the patients. The median KPS remained stable over the whole observation period (70% vs. 70%). Spinal fusion was observed in nine out of nine patients who received CT follow-up >120 days after index surgery. Conclusions: This study showed that pVCR is a safe surgical technique with few surgical complications and no neurological deterioration considering the cohort. The patients’ segmental kyphosis and VAS improved significantly, while the KPS remained stable.

The Hamburg Spondylodiscitis Assessment Score (HSAS) for Immediate Evaluation of Mortality Risk on Hospital Admission

(1) Background: Patients with spondylodiscitis often present with unspecific and heterogeneous symptoms that delay diagnosis and inevitable therapeutic steps leading to increased mortality rates of up to 27%. A rapid initial triage is essential to identify patients at risk for a complicative disease course. We therefore aimed to develop a risk assessment score using fast available parameters to predict in-hospital mortality of patients admitted with spondylodiscitis. (2) Methods: A retrospective data analysis of 307 patients with spondylodiscitis recruited from 2013 to 2020 was carried out. Patients were grouped according to all-cause mortality. Via logistic regression, individual patient and clinical characteristics predictive of mortality were identified. A weighted sum score to estimate a patient's risk of mortality was developed and validated in a randomly selected subgroup of spondylodiscitis patients. (3) Results: 14% of patients with spondylodiscitis died during their in-hospital stay at a tertiary center for spinal surgery. Univariate and logistic regression analyses of parameters recorded at hospital admission showed that age older than 72.5 years, rheumatoid arthritis, creatinine > 1.29 mg/dL and CRP > 140.5 mg/L increased the risk of mortality 3.9-fold, 9.4-fold, 4.3-fold and 4.1-fold, respectively. S. aureus detection increased the risk of mortality by 2.3-fold. (4) Conclusions: The novel Hamburg Spondylodiscitis Assessment Score (HSAS) shows a good fit identifying patients at low-, moderate-, high- and very high risk for in hospital mortality on admission (AUC: 0.795; p < 0.001). The implementation of the HSAS into clinical practice could ease identification of high-risk patients using readily available parameters alone, improving the patient's safety and outcome.

Surgical Site Cytology to Diagnose Spinal Lesions

Patients with new-onset malignant spinal lesions often have an urgent need for local spine intervention and systemic therapy. For optimal management, it is crucial to diagnose the underlying disease as quickly and reliably as possible. The aim of our current study was to determine the feasibility, sensitivity, specificity, and diagnostic certainty of complementary cytological evaluation of spinal lesions suspected of malignancy. In 44 patients, we performed histopathological biopsies and in parallel cytologic preparations from the malignant site. Cytological smears were prepared and stained for May-Grunwald and Giemsa. Bone biopsies were histopathologically analyzed according to the existing standard-of-care practices. In 42 of 44 cases (95%), a cytological sample was successfully obtained. In 40 cases (95.2%, Cohen’s kappa: 0.77), the cytological diagnosis agreed with the histological diagnosis regarding the identification of a malignant lesion. This resulted in a sensitivity of 97% and a specificity of 80% as well as a diagnostic safety of 95%. Cytological analysis in the context of spinal surgery proved sufficient to establish a diagnosis of malignancy or its exclusion, expanding the existing diagnostic spectrum. Furthermore, implementation of this process as a routine clinical diagnostic might shorten the time to diagnosis and improve the treatment of this vulnerable patient group.

eCross-cultural adaptation of the spine oncology-specific SOSGOQ2.0 questionnaire to German language and the assessment of its validity and reliability in the clinical setting

Background

The recently developed Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0) was proven a valid and reliable instrument measuring health-related quality of life (HRQOL) for patients with spinal malignancies. A German version was not available.

Objective

A cross-cultural adaptation of the SOSGOQ2.0 to the German language and its multicenter evaluation.

Methods

In a multistep process, a cross-cultural adaptation of the SOSGOQ2.0 was conducted. Subsequently, a multicenter, prospective observational cohort study was initiated to assess the reliability and validity of the German adaptation. To assess external construct validity of the cross-cultural adapted questionnaire, a comparison to the established questionnaire QLQ-C30 from the European Organisation for Research and Treatment of Cancer was conducted. Mean-difference plots were used to measure the agreement between the questionnaires in total score and by domain (deviation from mean up to 10% allowed). Further reliability and validity tests were carried out. Change to baseline was analysed 3–16 weeks later after different interventions occurred. Clinically relevant thresholds in comparison to the EORTC QLQ-C30 questionnaire were evaluated by ROC curve analysis.

Results

We could enroll 113 patients from four different university hospitals (58 females, 55 males). Mean age was 64.11 years (sd 11.9). 80 patients had an ECOG performance status of 2 or higher at baseline. External construct validity in comparison to the EORTC QLQ-C30 questionnaire in total score and by domain was confirmed (range of deviation 4.4 to 9.0%). Good responsiveness for the domains Physical Functioning (P < .001) and Pain (P < .001) could be shown. The group mean values also displayed a difference in the domains of Social Functioning (P = .331) and Mental Health (P = .130), but not significant. The minimum clinically relevant threshold values for the questionnaire ranged from 4.0 to 7.5 points.

Conclusions

According to our results, the cross-cultural adapted questionnaire is a reliable and valid tool to measure HRQOL in German speaking patients with spinal malignancies. Especially the domains Physical Functioning and Pain showed overall good psychometric characteristics. In this way, a generic questionnaire, such as the EORTC QLQ-C30, can be usefully supplemented by spine-specific questions to increase the overall accuracy measuring HRQOL in patients with spinal malignancies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08578-x.

Spontaneous spondylodiscitis and endocarditis: interdisciplinary experience from a tertiary institutional case series and proposal of a treatment algorithm

Previously, the simultaneous presence of endocarditis (IE) has been reported in 3–30% of spondylodiscitis cases. The specific implications on therapy and outcome of a simultaneous presence of both diseases are not yet fully evaluated. Therefore, the aim of this study was to investigate the influence of a simultaneously present endocarditis on the course of therapy and outcome of spondylodiscitis. A prospective database analysis of 328 patients diagnosed with spontaneous spondylodiscitis (S) using statistical analysis with propensity score matching was conducted. Thirty-six patients (11.0%) were diagnosed with concurrent endocarditis (SIE) by means of transoesophageal echocardiography. In our cohort, the average age was 65.82 ± 4.12 years and 64.9% of patients were male. The incidence of prior cardiac or renal disease was significantly higher in the SIE group (coronary heart disease SIE n = 13/36 vs. S n = 57/292, p < 0.05 and chronic heart failure n = 11/36 vs. S n = 41/292, p < 0.05, chronic renal failure SIE n = 14/36 vs. S n = 55/292, p < 0.05). Complex interdisciplinary coordination and diagnostics lead to a significant delay in surgical intervention (S = 4.5 ± 4.5 days vs. SIE = 8.9 ± 9.5 days, p < 0.05). Mortality did not show statistically significant differences: S (13.4%) and SIE (19.1%). Time to diagnosis and treatment is a key to efficient treatment and patient safety. In order to counteract delayed therapy, we developed a novel therapy algorithm based on the analysis of treatment processes of the SIE group. We propose a clear therapy pathway to avoid frequently observed pitfalls and delays in diagnosis to improve patient care and outcome.

Influence of microbiological diagnosis on the clinical course of spondylodiscitis

Purpose

This study sought to recognize differences in clinical disease manifestations of spondylodiscitis depending on the causative bacterial species.

Methods

We performed an evaluation of all spondylodiscitis cases in our clinic from 2013–2018. 211 patients were included, in whom a causative bacterial pathogen was identified in 80.6% (170/211). We collected the following data; disease complications, comorbidities, laboratory parameters, abscess occurrence, localization of the infection (cervical, thoracic, lumbar, disseminated), length of hospital stay and 30-day mortality rates depending on the causative bacterial species. Differences between bacterial detection in blood culture and intraoperative samples were also recorded.

Results

The detection rate of bacterial pathogens through intraoperative sampling was 66.3% and could be increased by the results of the blood cultures to a total of 80.6% (n = 170/211). S. aureus was the most frequently detected pathogen in blood culture and intraoperative specimens and and was isolated in a higher percentage cervically than in other locations of the spine. Bacteremic S. aureus infections were associated with an increased mortality (31.4% vs. overall mortality of 13.7%, p = 0.001), more frequently developing complications, such as shock, pneumonia, and myocardial infarction. Comorbidities, abscesses, length of stay, sex, and laboratory parameters all showed no differences depending on the bacterial species.

Conclusion

Blood culture significantly improved the diagnostic yield, thus underscoring the need for a structured diagnostic approach. MSSA spondylodiscitis was associated with increased mortality and a higher incidence of complications.

Implementation of a multidisciplinary infections conference improves the treatment of spondylodiscitis

Establishing a multidisciplinary approach regarding the treatment of spondylodiscitis and analyzing its effect compared to a single discipline approach. 361 patients diagnosed with spondylodiscitis were included in this retrospective pre-post intervention study. The treatment strategy was either established by a single discipline approach (n = 149, year 2003–2011) or by a weekly multidisciplinary infections conference (n = 212, year 2013–2018) consisting of at least an orthopedic surgeon, medical microbiologist, infectious disease specialist and pathologist. Recorded data included the surgical and antibiotic strategy, complications leading to operative revision, recovered microorganisms, as well as the total length of hospital and intensive care unit stay. Compared to a single discipline approach, performing the multidisciplinary infections conference led to significant changes in anti-infective and surgical treatment strategies. Patients discussed in the conference showed significantly reduced days of total antibiotic treatment (66 ± 31 vs 104 ± 31, p < 0.001). Moreover, one stage procedures and open transpedicular screw placement were more frequently performed following multidisciplinary discussions, while there were less involved spinal segments in terms of internal fixation as well as an increased use of intervertebral cages instead of autologous bone graft (p < 0.001). Staphylococcus aureus and Staphylococcus epidermidis were the most frequently recovered organisms in both patient groups. No significant difference was found comparing inpatient complications between the two groups or the total in-hospital stay. Implementation of a weekly infections conference is an effective approach to introduce multidisciplinarity into spondylodiscitis management. These conferences significantly altered the treatment plan compared to a single discipline approach. Therefore, we highly recommend the implementation to optimize treatment modalities for patients.

Intraoperative blood loss in oncological spine surgery

OBJECTIVE

Intraoperative blood loss in patients undergoing oncological spine surgery poses a major challenge for vulnerable patients. The goal of this study was to assess how the surgical procedure, tumor type, and tumor anatomy, as well as anesthesiological parameters, affect intraoperative blood loss in oncological spine surgery and to use this information to generate a short preoperative checklist for spine surgeons and anesthesiologists to identify patients at risk for increased intraoperative blood loss.

METHODS

The authors performed a retrospective analysis of 430 oncological patients who underwent spine surgery between 2013 and 2018 at the university medical spine center. Enrolled patients had metastatic tumor of the spine requiring surgical decompression of neural structures and/or stabilization including tumor biopsy using an open, percutaneous, and/or combined dorsoventral approach. Patients requiring vertebro- and kyphoplasty or biopsy only were excluded. Statistical analyses performed included a multiple linear regression analysis.

RESULTS

The mean intraoperative blood loss in the study patient cohort was 1176 ± 1209 ml. In total, 33.8% of patients received intraoperative red blood cell transfusions. The statistical analyses showed that tumor histology indicating myeloma, operative procedure length, epidural spinal cord compression (ESCC) score, tumor localization, BMI, and surgical strategy were significantly associated with increased intraoperative blood loss or risk of needing allogeneic blood transfusions. Anesthesiological parameters such as the American Society of Anesthesiologists (ASA) Physical Status classification score were not associated with blood loss. Multiple linear regression analysis demonstrated good predictive value (r = 0.437) for a five-item preoperative checklist to identify patients at risk for high intraoperative blood loss.

CONCLUSIONS

The analyses performed in this study demonstrated key factors affecting intraoperative blood loss and showed that a simple preoperative checklist including these factors can be used to identify patients undergoing surgery for metastatic spine tumors who are at risk for increased intraoperative blood loss.

ABBREVIATIONS

ABT = allogeneic blood transfusion; ASA = American Society of Anesthesiologists; ESCC = epidural spinal cord compression; KW = Kruskal-Wallis; MET = metabolic equivalent of task; RBC = red blood cell.

Posterior vertebral column resection as a safe procedure leading to solid bone fusion in metastatic epidural spinal cord compression

OBJECTIVE

Cancer is one of the leading causes of death and greatly decreases a patient's quality of life. Vertebral metastases often lead to epidural spinal cord compression (ESCC) requiring surgical therapy. It has previously been shown that in patients with metastatic ESCC (MESCC), a surgical intervention leads to an improved outcome. Although the treatment paradigms in spinal metastases have changed and separation surgery followed by stereotactic radiosurgery is considered the best strategy, there are still cases in which 360° decompression with stabilization is indicated. In these patients, a proper bone fusion should be the treatment goal to guarantee good clinical results in extended survival times through progressions in oncological therapies. The aim of this study was to examine the safety and feasibility of posterior vertebral column resection (pVCR) in everyday clinical practice, achievement of bone fusion, and midterm outcome in patients with MESCC.

METHODS

All patients treated with pVCR due to MESCC between 2013 and 2020 were enrolled in this observational single-center study. Demographics, outcome parameters, numeric rating scale (NRS) score, Frankel grade, and Karnofsky Performance Scale (KPS) score were evaluated. Radiological images routinely acquired during follow-up were reviewed and screened for the presence of bone fusion.

RESULTS

Sixty-six patients were treated by eight surgeons. The mean follow-up period was 549 ± 739 days. At baseline, the average age was 64.4 ± 10.9 years. Reported NRS scores (preoperative 6.2 ± 1.7 vs postoperative 3.4 ± 1.6) and segmental kyphosis as measured on sagittal CT images (preoperative 13.5° ± 8.6° vs postoperative 3.8° ± 5.4°) decreased significantly (p < 0.001). In only 2 patients (3%), the Frankel grade worsened postoperatively, whereas in 12 patients (18.2%) an improvement was documented. The KPS score remained constant during the observation period (preoperative 73.2% ± 18.2% vs 78.3% ± 18% at last follow-up). Bone fusion was observed in 26 patients (86.7%) receiving CT more than 100 days after the index surgery.

CONCLUSIONS

pVCR is a reliable surgical technique in daily clinical practice, which proves to be beneficial in terms of short- as well as midterm outcome, as judged by the KPS and NRS. The overall improvement in the Frankel grade shows patient safety. A bone fusion was observed regularly in oncological patients undergoing pVCR. The authors therefore conclude that pVCR is a safe, fast, and efficient strategy to achieve stability and pain relief by achievement of bone fusion in cancer patients.

Surgical management of spinal metastases involving the cervicothoracic junction: results of a multicenter, European observational study

OBJECTIVE

Surgical management of spinal metastases at the cervicothoracic junction (CTJ) is highly complex and relies on case-based decision-making. The aim of this multicentric study was to describe surgical procedures for metastases at the CTJ and provide guidance for clinical and surgical management.

METHODS

Patients eligible for this study were those with metastases at the CTJ (C7-T2) who had been consecutively treated in 2005-2019 at 7 academic institutions across Europe. The Spine Instability Neoplastic Score, neurological function, clinical status, medical history, and surgical data for each patient were retrospectively assessed. Patients were divided into four surgical groups: 1) posterior decompression only, 2) posterior decompression and fusion, 3) anterior corpectomy and fusion, and 4) anterior corpectomy and 360° fusion. Endpoints were complications, surgical revision rate, and survival.

RESULTS

Among the 238 patients eligible for inclusion this study, 37 were included in group 1 (15%), 127 in group 2 (53%), 18 in group 3 (8%), and 56 in group 4 (24%). Mechanical pain was the predominant symptom (79%, 189 patients). Surgical complications occurred in 16% (group 1), 20% (group 2), 11% (group 3), and 18% (group 4). Of these, hardware failure (HwF) occurred in 18% and led to surgical revision in 7 of 8 cases. The overall complication rate was 34%. In-hospital mortality was 5%.

CONCLUSIONS

Posterior fusion and decompression was the most frequently used technique. Care should be taken to choose instrumentation techniques that offer the highest possible biomechanical load-bearing capacity to avoid HwF. Since the overall complication rate is high, the prevention of in-hospital complications seems crucial to reduce in-hospital mortality.

Bacterial adhesion characteristics on implant materials for intervertebral cages: titanium or PEEK for spinal infections?

PURPOSE

Surgical intervention with intercorporal stabilisation in spinal infections is increasingly needed. Our aim was to compare titanium and polyetheretherketon (PEEK) cages according to their adhesion characteristics of different bacteria species in vitro.

METHODS

Plates made from PEEK, polished titanium (Ti), two-surface-titanium (TiMe) (n = 2-3) and original PEEK and porous trabecular structured titanium (TiLi) interbody cages (n = 4) were inoculated in different bacterial solutions, S.aureus (MSSA, MRSA), S.epidermidis and E.coli. Growth characteristics were analysed. Biofilms and bacteria were visualised using confocal- and electron microscopy.

RESULTS

Quantitative adherence of MSSA, MRSA, S.epidermidis and E.coli to Ti, TiMe and PEEK plates were different, with polished titanium being mainly advantageous over PEEK and TiMe with significantly less counts of colony forming units (CFU) for MRSA after 56 h compared to TiMe and at 72 h compared to PEEK (p = 0.04 and p = 0.005). For MSSA, more adherent bacteria were detected on PEEK than on TiMe at 32 h (p = 0.02). For PEEK and TiLi cages, significant differences were found after 8 and 72 h for S.epidermidis (p = 0.02 and p = 0.008) and after 72 h for MSSA (p = 0.002) with higher bacterial counts on PEEK, whereas E.coli showed more CFU on TiLi than PEEK (p = 0.05). Electron microscopy demonstrated enhanced adhesion in transition areas.

CONCLUSION

For S.epidermidis, MSSA and MRSA PEEK cages showed a higher adherence in terms of CFU count, whereas for E.coli PEEK seemed to be advantageous. Electron microscopic visualisation shows that bacteria did not adhere at the titanium mesh structure, but at the border zones of polished material to rougher parts.

Obesity in spontaneous spondylodiscitis: a relevant risk factor for severe disease courses

Spondylodiscitis is a serious and potentially life-threatening disease. Obesity is a risk factor for many infections, and its prevalence is increasing worldwide. Thus, the aim of this study was to describe characteristics of obese patients with spondylodiscitis and identify risk factors for a severe disease course in obese patients. Between December 2012 and June 2018, clinical records were screened for patients admitted for spondylodiscitis. The final analysis included 191 adult patients (mean age 64.6 ± 14.8 years). Patient data concerning demographics, comorbidities, surgical treatment, laboratory testing, and microbiological workup were analysed using an electronic database. Patients were grouped according to body mass index (BMI) as BMI ≥ 30 kg/m² or < 30 kg/m². Seventy-seven patients were classified as normal weight (BMI 18.5-24.9 kg/m²), 65 as preobese (BMI 25-29.9 kg/m²), and 49 as obese (BMI ≥ 30 kg/m²). Obese patients were younger, had a higher revision surgery rate, and showed higher rates of abscesses, neurological failure, and postoperative complications. A different bacterial spectrum dominated by staphylococci species was revealed (p = 0.019). Obese patients with diabetes mellitus had a significantly higher risk for spondylodiscitis (p = 0.002). The mortality rate was similar in both cohorts, as was the spondylodiscitis localisation. Obesity, especially when combined with diabetes mellitus, is associated with a higher proportion of Staphylococcus aureus infections and is a risk factor for a severe course of spondylodiscitis, including higher revision rates and sepsis, especially in younger patients.

[Posterior vertebral column resection for correction of kyphotic deformity due to osteoporotic fractures of the thoracic spine]

OBJECTIVE

The posterior vertebral column resection (PVCR) comprises a one-step resection of the vertebral body by a costotransversectomy together with a 360° spondylodesis. After removing the vertebral body, straightening of the existing kyphotic malposition is possible.

INDICATIONS

Pronounced thoracic kyphosis after osteoporotic sintering fractures in one or more vertebral bodies.

CONTRAINDICATIONS

General contraindications for surgical procedures, ASA >3 (American Society of Anesthesiologists).

SURGICAL TECHNIQUE

First, dorsal stabilization of the vertebral column on at least two levels cranial and caudal of the VCR. Next, in a one-step procedure the laminectomy with costotransversectomy and the resection of the vertebral body is done. The ventral defect gap is filled by a mesh cage to provide ventral support. By compression the malposition is reduced and the mesh cage is fixed into position. Finally the vertebrae joints are opened up using a chisel and bone or bone substitute is placed to complete the 360° spondylodesis.

POSTOPERATIVE MANAGEMENT

Functional treatment without peak load exercises as well as appropriate osteoporosis treatment.

RESULTS

In a retrospective study 10 patients treated with this surgical technique were investigated. The results show a very good correction of the kyphotic maldeformity while the complications remain moderate.

Intraocular pressure during neurosurgical procedures in context of head position and loss of cerebrospinal fluid

OBJECTIVE

Perioperative visual loss (POVL) is a rare but serious complication in surgical disciplines, especially in spine surgery. The exact pathophysiology of POVL remains unclear, but elevated intraocular pressure (IOP) is known to be part of it. As POVL is rarely described in patients undergoing intracranial or intradural surgery, the aim of this study was to investigate the course of IOP during neurosurgical procedures with opening of the dura mater and loss of CSF.

METHODS

In this prospective, controlled trial, 64 patients fell into one of 4 groups of 16 patients each. Group A included patients undergoing spine surgery in the prone position, group B patients had intracranial procedures in the prone position, and group C patients were treated for intracranial pathologies in a modified lateral position with the head rotated. In groups A-C, the dura was opened during surgery. Group D patients underwent spine surgeries in the prone position with an intact dura. IOP was measured continuously pre-, peri-, and postoperatively.

RESULTS

In all groups, IOP decreased after induction of anesthesia and increased time dependently after final positioning for the operation. The maximum IOP in group A prior to opening of the dura was 28.6 ± 6.2 mm Hg and decreased to 23.44 ± 4.9 mm Hg directly after dura opening (p < 0.0007). This effect lasted for 30 minutes (23.5 ± 5.6 mm Hg, p = 0.0028); after 60 minutes IOP slowly increased again (24.5 ± 6.3 mm Hg, p = 0.15). In group B, the last measured IOP before CSF loss was 28.1 ± 5.0 mm Hg and decreased to 23.5 ± 6.1 mm Hg (p = 0.0039) after dura opening. A significant IOP decrease in group B lasted at 30 minutes (23.6 ± 6.0 mm Hg, p = 0.0039) and 60 minutes (23.7 ± 6.0 mm Hg, p = 0.0189). In group C, only the lower eye showed a decrease in IOP up to 60 minutes after loss of CSF (opening of dura, p = 0.0007; 30 minutes, p = 0.0477; 60 minutes, p = 0.0243). In group D (control group), IOP remained stable throughout the operation after the patient was prone.

CONCLUSIONS

This study is the first to demonstrate that opening of the dura with loss of CSF during neurosurgical procedures results in a decrease in IOP. This might explain why POVL predominantly occurs in spinal but rarely in intracranial procedures, offers new insight to the pathophysiology of POVL, and provides the basis for further research and treatment of POVL.German Clinical Trials Register (DRKS) no.: DRKS00007590 (drks.de).

[Dorsal stabilization of C1/C2 modified according to Goel-Harms with C1 pedicle screws]

OBJECTIVE

Stabilization of the atlantoaxial transition by an alternative screw position in C1.

INDICATIONS

Instabilities C1/C2 due to inflammation, tumor or trauma.

CONTRAINDICATIONS

Presence of a very small pedicle of C1. Variations in the course of the vertebral arteries.

SURGICAL TECHNIQUE

The midline approach to the upper cervical spine is used for the modified instrumentation of C1 with pedicle screws instead of Harms screws and for the unaltered instrumentation of C2. Depending on the indication, dorsal spondylodesis is performed by opening the laminae and attaching ceramic bone substitute material.

POSTOPERATIVE MANAGEMENT

In mobile patients, additional immobilisation with a soft collar is recommended for 6 weeks. Full recovery is given 3-4 months after surgery.

RESULTS

From January 2017 to September 2018, 21 stabilizations of the atlantoaxial transition were performed. The mean age was 72.52 ± 15.45 years. A total of 42 screws were placed in C1. In all, 21 (50%) C1 pedicle screwscould be placed, and in other 21 cases Harms screws were used. Complications were seen in 3 patients. Overall, considering the contraindications, the instrumentation of C1 with pedicle screws appears as a safe alternative to instrumentation with Harms screws.

To fuse or not to fuse: a survey among members of the German Spine Society (DWG) regarding lumbar degenerative spondylolisthesis and spinal stenosis

INTRODUCTION

Surgical treatment methods for degenerative spondylolisthesis (decompression versus decompression and fusion) have been critically debated. The medical care situation is almost unknown for either treatment. Therefore, the aim of the present study was to provide information regarding the use of parameters for decision-making and the employment of surgical techniques.

MATERIALS AND METHODS

A web-based survey was performed among members of the German-Spine-Society (DWG). Information regarding participant characteristics (specialty, age, DWG certification status, number of spine surgeries performed at the participant's institution each year, institutional status), estimates of the use of both treatment options, clinical and morphological decision-making criteria for additive fusion, and the surgical technique used was queried.

RESULTS

305 members (45% neurosurgeons/ 55% orthopedic or trauma surgeons) participated in the present study. The participants estimated that in 41.7% of the cases, decompression only was required, while 55.6% would benefit from additional fusion. Among the participants, 74% reported that low back pain was an important indicator of the need for fusion if the numerical rating scale for back pain was at least 6/10. The most commonly used decompression technique was minimally invasive unilateral laminotomy, whereas open approach-based interbody fusion with transpedicular fixation and laminotomy was the most frequently used fusion technique. Specialty, age, certification status, and institutional status had a partial effect on the responses regarding indications, treatment and surgical technique.

CONCLUSIONS

The present survey depicts the diversity of approaches to surgery for degenerative spondylolistheses in Germany. Considerable differences in treatment selection were observed in relation to the participants' educational level and specialty.

Congenital deformation of the posterior arch of the atlas: Subluxation of the atlanto-axial joint with temporary quadriplegia

Instabilities of the craniocervical junction can be of rheumatic, traumatic, or congenital origin. The reported patient has a congenital malformation of the cervical spine, which is frequently observed in patients with Klippel–Feil syndrome. Her posterior arch of the atlas (C1) is hypoplastic and a chronic subluxation of the atlanto-axial joint would be possible. Although most common fusions in Klippel–Feil syndrome patients exist at C2/3, the majority of studies about Klippel–Feil syndrome deal with pediatric or adolescent individuals. Through extreme flexion of her neck, there was a compression of the spinal cord by the odontoid process. This led to a quadriplegia lasting about 10 min. Over the following weeks, all of her symptoms started to diminish. This situation turned out to be the third episode involving temporary neurological disorders in this 60-year-old female’s life.

Recommendations for the Diagnostic Testing and Therapy of Atlas Fractures

Im Jahr 2017 erstellten die Mitglieder der AG „obere HWS“ der Sektion „Wirbelsäule“ der DGOU in einem Konsensusprozess mit 4 Sitzungen Empfehlungen zur Diagnostik und Therapie oberer Halswirbelsäulenverletzungen unter Berücksichtigung der aktuellen Literatur. Der folgende Artikel beschreibt die Empfehlung für Frakturen des Atlasrings. Etwa 10% aller HWS-Verletzungen betreffen den Atlas. Die Diagnostik zielt im Wesentlichen auf die Detektion der Verletzung sowie die Beurteilung der Gelenkflächen hinsichtlich einer Lateralisationstendenz der Atlasmassive. Zur Klassifikation haben sich die Gehweiler-Klassifikation und ergänzend die Dickman-Klassifikation bewährt. Zum primären klinischen Screening hat sich die Canadian C-Spine Rule bewährt. Bildgebendes Verfahren der Wahl bei klinischem Verdacht auf eine Atlasverletzung ist die CT. Die MRT dient der Beurteilung der Integrität des Lig. transversum atlantis bei vorderer und hinterer Bogenfraktur. Die Indikation zur Gefäßdarstellung sollte großzügig gestellt werden. Viele Atlasfrakturen können konservativ in einer Zervikalorthese behandelt werden. Eine OP-Indikation ist gegeben bei bestehender oder drohender massiver Gelenkinkongruenz oder -instabilität, die am häufigsten bei Gehweiler-IIIB-Frakturen oder bei Gehweiler-IV-Frakturen vorliegt. Operative Standardtherapie ist die dorsale atlantoaxiale Fixation, entweder in transartikulärer Technik oder mittels Fixateur interne. Insbesondere bei jüngeren Patienten sollte die Möglichkeit einer isolierten Atlasosteosynthese geprüft werden. Dislozierte Gehweiler-IV-Frakturen mit sagittaler Spaltbildung können auch probatorisch im Halofixateur unter Ausnutzung der Ligamentotaxis behandelt werden; eine engmaschige Dislokationskontrolle ist obligat. Im Falle einer sekundären Dislokation ist auch hier eine operative Stabilisierung indiziert. Bei Mitbeteiligung des okzipitozervikalen Gelenks ist eine Einbeziehung des Okziputs in die Instrumentierung notwendig.

Recommendations for Diagnosis and Treatment of Fractures of the Ring of Axis

In a consensus process with four sessions in 2017, the working group “upper cervical spine” of the German Society for Orthopaedics and Trauma Surgery (DGOU) formulated “Therapeutic Recommendations for the Diagnosis and Treatment of Upper Cervical Fractures”, taking their own experience and the current literature into consideration. The following article describes the recommendations for axis ring fractures (traumatic spondylolysis C2). About 19 to 49% of all cervical spine injuries include the axis vertebra. Traumatic spondylolysis of C2 may include potential discoligamentous instability C2/3. The primary aim of the diagnostic process is to detect the injury and to determine potential disco-ligamentous instability C2/3. For classification purposes, the Josten classification or the modified Effendi classification may be used. The Canadian C-spine rule is recommended for clinical screening for C-spine injuries. CT is the preferred imaging modality and an MRI is needed to determine the integrity of the discoligamentous complex C2/3. Conservative treatment is appropriate in case of stable fractures with intact C2/3 motion segment (Josten type 2 and 2). Patients should be closely monitored, in order to detect secondary dislocation as early as possible. Surgical treatment is recommended in cases of primary severe fracture dislocation or discoligamentous instability C2/3 (Josten 3 and 4) and/or secondary fracture dislocation. Anterior cervical decompression and fusion (ACDF) C2/3 is the treatment of choice. However, in case of facet joint luxation C2/3 with looked facet (Josten 4), a primary posterior approach may be necessary.

Cervical vertebroplasty for osteolytic metastases as a minimally invasive therapeutic option in oncological surgery: outcome in 14 cases

OBJECTIVE The treatment of cervical spinal metastases represents a controversial issue regarding the type, extent, and invasiveness of interventions. In the lumbar and thoracic spine, kypho- and vertebroplasties have been established as minimally invasive procedures for patients with metastases to the vertebral bodies and without neurological deficit. These procedures show good results with respect to pain reduction and low complication rates. However, limited data are available for kypho- and vertebroplasties for cervical spinal metastases. In an effort to add to existing data, the authors here present a case series of 14 patients who were treated for osteolytic metastases of the cervical spine using vertebroplasty alone or in addition to another surgical procedure involving the cervical spine in a palliative setting to reduce pain and restore stability. METHODS Fourteen patients consisting of 8 males and 6 females, with a mean age of 64.7 years (range 44-85 years), were treated with vertebroplasty at the authors' clinic between January 2015 and November 2016. In total, 25 vertebrae were treated with vertebroplasty: 10 C-2, 5 C-3, 2 C-4, 2 C-5, 3 C-6, and 3 C-7. Two patients had an additional posterior stabilization and 5 patients an additional anterior stabilization. In 13 cases, the surgical approach was a modified Smith-Robinson approach; in 1 case, the cement was injected into the corpus axis from posteriorly. Patients with osteolytic defects of the posterior wall of the vertebral body did not undergo surgery, nor did patients with neurological deficits. Preoperatively, on the 2nd day after surgery, and at the follow-up, neck pain was rated using the visual analog scale (VAS). RESULTS Twelve patients were examined at follow-up (mean 9 months). Neck pain was rated as a mean of 6.0 (range 3-8) preoperatively, 2.9 on Day 2 after surgery (range 0-5), and 0.5 at the follow-up (range 0-4), according to the VAS. The mean Neck Disability Index at follow-up was 3.6% (range 0%-18%). CONCLUSIONS Anterior vertebroplasty of the cervical spine via an anterolateral approach represents a safe and minimally invasive procedure with a low complication rate and appears suitable for reducing pain and restoring stability in cases of cervical spinal metastases. Vertebroplasties can be combined with other anterior and posterior operations of the cervical spine and, in the axis vertebra, can be performed transpedicularly from posteriorly. Thus, in cases in which the posterior wall of the vertebral body is intact, vertebroplasty represents a less invasive alternative to vertebral replacement in oncological surgery. Prospective randomized trials with a longer follow-up period and a larger patient cohort are needed to confirm the encouraging results of this case series.

Basilar impression as complication of Grisel's syndrome

Grisel's syndrome presents a rare disease. Here, we present a peculiar case of Grisel's syndrome with an unfavorable course developing a basilar impression. This highlights the importance of close clinical and radiological follow‐up even in cases where the course seems uncomplicated.

Surgical treatment of spinal metastases from renal cell carcinoma-effects of preoperative embolization on intraoperative blood loss

The objective of this paper is analyzing the effects of preoperative embolization on intraoperative blood loss in spinal surgery for renal cell carcinoma (RCC) metastasis and identifying factors contributing to an increased blood loss in the surgical procedure. A retrospective analysis was performed in patients who were treated in for spinal metastasis from RCC between 2011 and 2016. Factors analyzed were reduction of tumor blush, timing of embolization, selective vs. superselective approach, surgical factors, and tumor volume and localization. Parameters were statistically correlated with intraoperative blood loss (hemoglobin (Hg) decrease, blood loss in milliliters, number of transfused blood bags). Twenty-five patients with 34 surgical interventions were included. Seventeen cases were treated superselectively and 11 treated selectively. Mean perioperative blood loss was 2248 ± 1833 ml. Higher blood loss was detected for vertebra replacement compared to percutaneous procedures (Hg decrease 4.22 vs. 2.62, p < 0.05). Blood loss increased with increasing tumor volumes (0-50 ccm/50-100 ccm/> 100 ccm) for Hg loss (3.29/3.64/4.24 mg/dl, NS), blood loss in milliliters (1291/2620/4971 ml, p < 0.001), and number of transfusions (1.2/3.4/7.0, p < 0.001). Stratifying by the grade of embolization, no significant differences were found between the groups (> 90%/90-75%/75-50%) for Hg loss, blood loss, or number of transfusions. Endovascular embolization for RCC metastasis of the spine is a safe procedure; however, in this cohort, patients undergoing embolization did not show a reduced blood loss in comparison to the non-embolized cohort. Additional factors contributing to an increased blood loss were tumor size and mode of surgery.

Body Mass Index >35 as Independent Predictor of Mortality in Severe Traumatic Brain Injury

OBJECTIVE

Severe traumatic brain injury (TBI) has a major influence on polytrauma outcome. The aim of this study was to evaluate the impact of body mass index (BMI) on mortality and early neurologic outcome in patients suffering from severe TBI with a special focus on obesity classes II and III (BMI ≥35).

METHODS

A retrospective cohort analysis of patients suffering from a leading, at least severe TBI and registered in the TraumaRegister DGU was conducted. Patients alive on admission with full status documentation on Glasgow Coma Scale, height, and weight were classified into 4 BMI subgroups. Early neurologic outcome was classified using the Glasgow Outcome Scale.

RESULTS

A total of 1634 patients met the inclusion criteria. Lowest mortality was documented for BMI group 1 (15.2%, BMI 25.0-29.9918.5). Highest mortality was found in BMI group 5 (25.6%, BMI ≥35). BMI ≥35 was an independent predictor of mortality with an odds ratio of 3.15 (95% confidence interval [1.06-9.36], P = 0.039). Further independent mortality predictors were >65 years of age, a Glasgow Coma Scale of ≤13, an Abbreviated Injury Scale_head ≥5, prehospital cardiopulmonary resuscitation, and a prehospital blood pressure of <90 mm Hg. In terms of good early neurologic outcomes, no differences were recorded between the BMI groups (range 59.0%-62.6%, P = 0.087).

CONCLUSIONS

In this study a BMI ≥35 is an independent predictor of mortality and is associated with an inferior early functional neurologic outcome.

Circulating Tumour Cell Release after Cement Augmentation of Vertebral Metastases

Cement augmentation via percutaneous vertebroplasty or kyphoplasty for treatment of spinal metastasis is a well-established treatment option. We assessed whether elevated intrametastatic pressure during cement augmentation results in an increased dissemination of tumour cells into the vascular circulation. We prospectively collected blood from patients with osteolytic spinal column metastases and analysed the prevalence of circulating tumour cells (CTCs) at three time-points: preoperatively, 20 minutes after cement augmentation, and 3–5 days postoperatively. Enrolling 21 patients, including 13 breast- (61.9%), 5 lung- (23.8%), and one (4.8%) colorectal-, renal-, and prostate-carcinoma patient each, we demonstrate a significant 1.8-fold increase of EpCAM+/K+ CTCs in samples taken 20 minutes post-cement augmentation (P < 0.0001). Despite increased mechanical CTC dissemination due to cement augmentation, follow-up blood draws demonstrated that no long-term increase of CTCs was present. Array-CGH analysis revealed a specific profile of the CTC collected 20 minutes after cement augmentation. This is the first study to report that peripheral CTCs are temporarily increased due to vertebral cement augmentation procedures. Our findings provide a rationale for the development of new prophylactic strategies to reduce the increased release of CTC after cement augmentation of osteolytic spinal metastases.

Posterior vertebral column resection with 360-degree osteosynthesis in osteoporotic kyphotic deformity and spinal cord compression

Osteoporotic fractures with severe kyphosis and neurologic deficits often require decompression and stabilisation. To reduce the risk of procedure-related complications, single-stage posterolateral vertebrectomy and a 360-degree fusion can be performed. An adequate reduction of kyphotic deformity through this approach has not been reported. The aim of this study is to investigate the efficacy of kyphotic deformity reduction by this approach in osteoporotic situation. A retrospective analysis and chart review was performed for 10 consecutive patients who underwent posterolateral decompression and posterior vertebrectomy with dorsal mesh stabilisation and reduction of kyphotic deformity. Preoperative back pain was 8.6 on a visual analogue scale; it was reduced to 5.5 at discharge and 3.7 at the latest follow-up (18 months). The Frankel score improved from D to E (three patients) or was equal (E). Radiological segmental kyphosis was corrected from a mean of 25° to 5° (p < 0.008) postoperatively with a loss of 3° at follow-up (p < 0.005). Single-stage posterolateral vertebrectomy allow for a fast and safe reconstitution/preservation of neurological function in patients with osteoporotic fracture and kyphotic deformity. A significant correction of often-accompanied hyperkyphosis is possible without neurological deterioration and with an improved sagittal profile and good pain reduction.

Cement augmentation versus extended dorsal instrumentation in the treatment of osteoporotic vertebral fractures: a biomechanical comparison

AIMS

Loosening of pedicle screws is a major complication of posterior spinal stabilisation, especially in the osteoporotic spine. Our aim was to evaluate the effect of cement augmentation compared with extended dorsal instrumentation on the stability of posterior spinal fixation.

MATERIALS AND METHODS

A total of 12 osteoporotic human cadaveric spines (T11-L3) were randomised by bone mineral density into two groups and instrumented with pedicle screws: group I (SHORT) separated T12 or L2 and group II (EXTENDED) specimen consisting of T11/12 to L2/3. Screws were augmented with cement unilaterally in each vertebra. Fatigue testing was performed using a cranial-caudal sinusoidal, cyclic (1.0 Hz) load with stepwise increasing peak force.

RESULTS

Augmentation showed no significant increase in the mean cycles to failure and fatigue force (SHORT p = 0.067; EXTENDED p = 0.239). Extending the instrumentation resulted in a significantly increased number of cycles to failure and a significantly higher fatigue force compared with the SHORT instrumentation (EXTENDED non-augmented + 76%, p < 0.001; EXTENDED augmented + 87%, p < 0.001).

CONCLUSION

The stabilising effect of cement augmentation of pedicle screws might not be as beneficial as expected from biomechanical pull-out tests. Lengthening the dorsal instrumentation results in a much higher increase of stability during fatigue testing in the osteoporotic spine compared with cement augmentation. Cite this article: Bone Joint J 2016;98-B:1099-1105.

Reducing kyphotic deformity by posterior vertebral column resection with 360° osteosynthesis in metastatic epidural spinal cord compression (MESCC)

PURPOSE

Metastatic epidural spinal cord compression (MESCC) often requires anterior-posterior decompression and stabilization. To reduce approach-related complications, single-stage posterolateral vertebrectomy and 360° fusion is often performed. However, a sufficient reduction of kyphotic deformity through this approach has not been reported. The purpose of this study is to investigate the efficacy of kyphotic deformity reduction by this approach in MESCC.

METHODS

A retrospective analysis and chart review was performed for 14 consecutive patients who underwent a vertebrectomy and decompression from a posterolateral approach. Anterior mesh stabilization of the ventral column is used as hypomochlion for the posterior compression manoeuvre, which leads to reduction of the kyphotic deformity.

RESULTS

Pre-operative back pain was 7.2 on a visual analogue scale. Back pain was reduced to 4.4 at discharge and 2.0 at the latest follow-up with a mean follow-up of 12 months (p < 0.001). The Frankel score remains constant or improved from D to E. Radiological segmental kyphosis was corrected from a mean of 16° to 4° (p < 0.001) post-operatively with a loss of 3° at the final follow-up, but still with significant corrections compared with the pre-operative measurements (p < 0.003).

CONCLUSION

Single-stage posterolateral vertebrectomy and reconstruction is a safe and less invasive approach that allows a sufficient reduction of hyperkyphosis and preservation of neurological function in patients with MESCC. This approach is an efficient alternative to anterior-posterior fusion with good pain reduction and improved sagittal profile.

Lumbar Neuroforaminal Decompression with a Flexible Microblade Shaver System: Results of a Cadaveric Study

BACKGROUND

The lumbar neural foraminal stenosis still is a challenging condition in minimally invasive spine surgery. Because of the anatomic situation a complete decompression of the nerve root often leads to a subtotal facetectomy associated with potential instability and the need for additional instrumentation of the decompressed segment. The iO-Flex system was introduced to address this problem by using a minimally invasive wire-guided microblade shaver to increase the neuroforaminal space by reducing the stenosis from intraforaminal while sparing bigger parts of the facet joint. In this study, we evaluated the feasibility and the surgical and radiological success in relation to the experience of the surgeon.

METHODS

We performed decompression of the neuroforamen in 10 lumbar levels of 2 fresh-frozen human cadavers. Before and after decompression, we obtained high-resolution computed tomography data to evaluate the diameter of the neural foramen.

RESULTS

The mean foraminal width (7.88-10.94 mm, P < 0.0001) and area (123.27-149.18 mm², P < 0.003) increased significantly after the decompression, whereas the facet joints area (131.9-107.51 mm², P < 0.005) and width (16.4-13.75 mm, P < 0.001) indeed decreased significantly but with an overall reduction of facet joint width by 16% and facet joint area by 18%. No complications such as nerve root damages or dural tears were observed.

CONCLUSIONS

The flexible micro blade shaver system is feasible with a steep learning curve and achieves sufficient decompression of the neuroforamen in this cadaveric study.

Retrospective feasibility analysis of modified posterior partial vertebrectomy with 360-degree decompression in destructive thoracic spondylodiscitis

BACKGROUND

Advanced states of vertebral osteomyelitis accompanied by spinal instability, epidural abscess formation, and neurological deficits require surgical decompression, stabilization, and often reconstruction of the anterior and posterior columns. The efficacy of a posterolateral approach with resection of inflammatory tissue, and interbody (titanium cages) and dorsal fusion was investigated and the clinical and radiological parameters (correction of kyphosis and fusion rates) were evaluated.

METHOD

From 2011 to 2014, ten consecutive patients were treated at our institution using the modified technique of a transversecomy without costal resection to decompress neural structures and resect inflammatory tissue in destructive thoracic vertebral osteomyelitis. Flattening of the endplates without complete corpectomy, 360-degree stabilization, and correction of kyphosis by posterior shortening instead of anterior distraction were performed to avoid an additional ventral approach. Clinical and radiological data were retrospectively analyzed.

RESULTS

All ten patients (six male and four female, mean age, 66 years) suffered from severe and destructive osteomyelitis. Surgery was performed successfully in all ten patients. Mean surgical time was 308 min. Mean follow-up was 19 months (range, 2-32 months). Neither approach-related or pulmonary complications nor recurrence of osteomyelitis were observed. All patients experienced pain relief after the procedure (mean back pain VAS was 8.8 pre-treatment and 3.2 at the final follow-up). Fusion was observed in all patients on the basis of computerized tomography scans. The mean radiological segmental kyphosis was corrected from 20° preoperatively to 7° after surgery and 9° at the final follow-up.

CONCLUSIONS

The modified posterior transversectomy with 360-degree decompression and anterior wall reconstruction with titanium cages in combination with posterior instrumentation for sagittal alignment correction is a reliable, effective, and safe treatment option.

Treatment of large thoracic and lumbar paraspinal schwannoma

BACKGROUND

Paraspinal neurogenic tumors usually expand into the mediastinum and retroperitoneum and can reach a considerable size before they become symptomatic. Such large tumors are rare. We describe 14 cases of large schwannomas (>2.5 cm ø) with mild and late onset of symptoms, which were treated with total surgical resection through a single-approach surgery.

METHODS

In 2013 14 patients with paraspinal large schwannomas were treated in our institutions. Data were analyzed retrospectively. Magnetic resonance imaging (MRI) showed lesions suspicious for a paraspinal schwannoma with partial intraforaminal growth. In case of ambiguity regarding tumor dignity, a needle biopsy was performed before final treatment. Three different approaches and their indications were discussed.

RESULTS

Fourteen patients (7 female and 7 male, ages 18-58 years, mean: 39.8 years) requiring surgical exploration because of a thoracic (6) or lumbar/lumbosacral (8) lesion were treated in our institutions. Two patients received CT-guided needle biopsy preoperatively. Complete resection of the schwannoma was possible through a mini-thoracotomy in 1 case (7 %), a retroperitoneal approach in 2 cases (14 %), and dorsal interlaminar and intercostal fenestration in 11 cases (79 %). Histological examination revealed the diagnosis of schwannoma (WHO grade I) in all cases except one with neurofibroma (WHO grade I). There were no major complications in any case.

CONCLUSION

Large benign schwannomas are rare. They need a tailored treatment, which in most cases works through one surgical approach. Usually it is possible to perform a complete resection with a good postoperative prognosis.

Correlation of histopathological findings and magnetic resonance imaging in the spine of patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease which affects primarily the sacroiliac joints and the spine. In patients with active disease, magnetic resonance imaging (MRI) of the spine shows areas of bone marrow edema, the histopathological equivalent of which is unknown. In this study we correlate inflammation in the spine of patients with AS as revealed by histological examination with bone marrow edema as detected by MRI. We have compared the histopathological findings of zygapophyseal joints from 8 patients with AS (age: 30 to 64, disease duration 7 to 33 years) undergoing spinal surgery with findings in MRI. For histopathological analysis, we quantified infiltrates of CD3+, CD4+ and CD8+ T cells as well as CD20+ B cells immunohistochemically. Bone marrow edema was evaluated in hematoxylin and eosin stained sections and quantified as the percentage of the bone marrow area involved. All patients with AS showed interstitial mononuclear cell infiltrates and various degrees of bone marrow edema (range from 10% to 60%) in histopathological analysis. However, in only three of eight patients histopathological inflammation and edema in the zygapophyseal joints correlated with bone marrow edema in zygapophyseal joints of the lumbar spine as detected by MRI. Interestingly, two of these patients showed the highest histological score for bone marrow edema (60%). This first study correlating histopathological changes in the spine of patients with AS with findings in MRI scans suggests that a substantial degree of bone marrow inflammation and edema is necessary to be detected by MRI.

Immunohistologic analysis of zygapophyseal joints in patients with ankylosing spondylitis

OBJECTIVE

Zygapophyseal joints of the spine are often affected in ankylosing spondylitis (AS). In this study, we undertook a systematic immunohistologic evaluation of the immunopathology of the zygapophyseal joints in patients with advanced AS.

METHODS

We obtained zygapophyseal joints from 16 AS patients undergoing polysegmental correction of kyphosis and from 10 non-AS controls (at autopsy). Immunohistologic analysis of the bone marrow was performed by analyzing the number of infiltrating T cells (CD3, CD4, CD8), B cells (CD20), osteoclasts (CD68), bone marrow macrophages (CD68), and microvessel density (CD34) per high-power field.

RESULTS

Zygapophyseal joints from 6 of 16 AS patients, but from none of the controls, exhibited 2 or more CD3+ T cell aggregates, signifying persistent inflammation. Interstitial CD4+ and CD8+ T cells were significantly more frequent in AS patients compared with non-AS controls (P = 0.002 and P = 0.049, respectively). While there was no clear difference between the number of CD20+ B cells in AS patients overall compared with controls, there was a significant difference when persistently inflamed joints from patients with AS were compared with joints without active inflammation from patients with AS or joints from controls (both P = 0.03). Microvessel density in bone marrow from AS patients with active inflammation was significantly higher than that in bone marrow from controls.

CONCLUSION

This immunohistologic study of bone marrow from zygapophyseal joints demonstrates persistent inflammation in the spine of patients with AS, including those with longstanding disease. The findings of increased numbers of T cells and B cells and neoangiogenesis suggest that these features play a role in the pathogenesis of AS.

Reduction of vertebral blood flow by segmental vessel occlusion: an intraoperative study using laser Doppler flowmetry

STUDY DESIGN

During anterior spinal surgery, vertebral perfusion was assessed by laser Doppler flowmetry. Blood flow changes were assessed after unilateral ligation and contralateral compression of the segmental vessels.

OBJECTIVE

To assess the influence of unilateral and bilateral segmental vessel occlusion on vertebral blood flow.

SUMMARY OF BACKGROUND DATA

During anterior spinal surgery, segmental vessels are frequently being ligated. The reduced blood supply to the vertebrae may impair intervertebral fusion, and the decreased spinal cord perfusion may lead to ischemic myelopathy. To our knowledge, this is the first in vivo study to investigate vertebral blood flow. METHODS.: There were 10 patients who underwent anterior release for adult idiopathic scoliosis (n = 6), Scheuermann disease (n = 3), and posttraumatic kyphosis (n = 1). A high-power laser Doppler flowmeter was used to assess vertebral blood flow. Measurements were performed in 19 thoracic and 4 lumbar vertebrae (n = 23) after unilateral segmental vessel ligation and additional temporary digital compression of the contralateral vessels.

RESULTS

Initial mean blood flow was 49.1 +/- 27.6 arbitrary units, and all signals were pulsatile. The blood flow decreased by a mean of 8% after unilateral ligation of the segmental vessels. With additional compression of the contralateral vessels, the signal heights decreased significantly by 54% (mean 18.3 +/- 7.8 arbitrary units, P = 0.00003), and a loss of the pulsatile pattern was observed in 75% of the vertebrae. On release of digital compression, the signal height as well as the pulsatility promptly returned.

CONCLUSIONS

Unilateral ligation of segmental vessels led only to a slight decrease of the vertebral blood flow. Future studies may show whether sparing the segmental vessels during anterior fusion enhances bone graft incorporation, thus decreasing the rate of pseudarthrosis. According to clinical data, the risk of neurologic injury through unilateral ligation is negligible. Bilateral segmental vessel occlusion markedly reduced vertebral bloodflow. Therefore, when treating patients with a higher neurologic risk or in revision cases, the surgeon should always consider sparing the segmental vessels.

Effect of drugs used for neuropathic pain management on tetrodotoxin-resistant Na(+) currents in rat sensory neurons

BACKGROUND

Tetrodotoxin-resistant Na(+) channels play an important role in generation and conduction of nociceptive discharges in peripheral endings of small-diameter axons of the peripheral nervous system. Pathophysiologically, these channels may produce ectopic discharges in damaged nociceptive fibers, leading to neuropathic pain syndromes. Systemically applied Na(+) channel--blocking drugs can alleviate pain, the mechanism of which is rather unresolved. The authors investigated the effects of some commonly used drugs, i.e., lidocaine, mexiletine, carbamazepine, amitriptyline, memantine, and gabapentin, on tetrodotoxin-resistant Na+ channels in rat dorsal root ganglia.

METHODS

Tetrodotoxin-resistant Na(+) currents were recorded in the whole-cell configuration of the patch-clamp method in enzymatically dissociated dorsal root ganglion neurons of adult rats. Half-maximal blocking concentrations were derived from concentration-inhibition curves at different holding potentials (-90, -70, and -60 mV).

RESULTS

Lidocaine, mexiletine, and amitriptyline reversibly blocked tetrodotoxin-resistant Na(+) currents in a concentration- and use-dependent manner. Block by carbamazepine and memantine was not use-dependent at 2 Hz. Gabapentin had no effect at concentrations of up to 3 mm. Depolarizing the membrane potential from -90 mV to -60 mV reduced the available Na(+) current only by 23% but increased the sensitivity of the channels to the use-dependent blockers approximately fivefold. The availability curve of the current was shifted by 5.3 mV to the left in 300 microm lidocaine.

CONCLUSIONS

Less negative membrane potential and repetitive firing have little effect on tetrodotoxin-resistant Na(+) current amplitude but increase their sensitivity to lidocaine, mexiletine, and amitriptyline so that concentrations after intravenous administration of these drugs can impair channel function. This may explain alleviation from pain by reducing firing frequency in ectopic sites without depressing central nervous or cardiac excitability.