Richard Bostelmann

Transnasal endoscopic odontoidectomy after occipito-cervical fusion during the same operative setting—technical note

Recently, a purely transnasal endoscopic approach (TNEA) for decompression of the anterior cranio-cervical junction has been described. At present, there is only a limited number of patients having been operated on in a few specialized centers. The possibilities, safety, and limits of this approach are still under investigation. The relationship between TNEA and occipito-cervical fusion, especially, which may typically be considered in this kind of pathologies, should be further elucidated. So far, the feasibility of TNEA after previous occipito-cervical fusion has only been reported for a single case. In that case, there was a posterior atlanto-axial subluxation and basilar invagination. In the present paper, another example of a surgical procedure of TNEA after previous posterior fusion during the same operative setting is given. It differs from the other case concerning the pathophysiology. In fact, here, there was anterior atlanto-axial subluxation and no basilar invagination. The possibilities and limits of this novel approach are thoroughly discussed. Special interest is given to the problem of CCJ instability and previous occipito-cervical fusion. Technical hints and pitfalls are described in detail.

Erratum to: Effect of augmentation techniques on the failure of pedicle screws under cranio-caudal cyclic loading

Purpose Augmentation of pedicle screws is recommended in selected indications (for instance: osteoporosis). Generally, there are two techniques for pedicle screw augmentation: inserting the screw in the non cured cement and in situ-augmentation with cannulated fenestrated screws, which can be applied percutaneously. Most of the published studies used an axial pull out test for evaluation of the pedicle screw anchorage. However, the loading and the failure mode of pullout tests do not simulate the cranio-caudal in vivo loading and failure mechanism of pedicle screws. The purpose of the present study was to assess the fixation effects of different augmentation techniques (including percutaneous cement application) and to investigate pedicle screw loosening under physiological cyclic cranio-caudal loading.

Reconstruction of septic diaphyseal bone defects with the induced membrane technique

Septic segmental bone voids of the diaphysis are difficult to manage. The induced membrane technique by Masquelet has been successfully used to reconstruct segmental defects more than 20 cm. Our article describes a series of 13 cases with extensive posttraumatic bone loss of the metatarsal, tibial, femoral and radial bones after septic injuries followed by multiple surgical interventions. Antibiotic-impregnated polymethyl methacrylate (PMMA) cement spacers were implanted after successful eradication of bacterial infections of soft tissue and bones. After a mean of 9.8 weeks, body-induced membranes were established and the cements spacers removed. To fill up the bone void, cancellous bone autografts were implanted into the membranes. The follow-up examination after 24 months revealed bony union in all cases and favorable functional results. The induced membrane technique has shown to be effective in treating bone defects of upper and lower extremity bone defects.

Biochemical validity of imaging techniques (X-ray, MRI, and dGEMRIC) in degenerative disc disease of the human cervical spine-an in vivo study.

BACKGROUND CONTEXT On a molecular level, maturation or degeneration of human intervertebral disc is among others expressed by the content of glycosaminoglycans (GAGs). According to the degenerative status, the disc content can differ in nucleus pulposus (NP) and annulus fibrosus (AF), respectively. Research in this area was conducted mostly on postmortem samples. Although several radiological classification systems exist, none includes biochemical features. Therefore, we focused our in vivo study on a widely spread and less expensive imaging technique for the cervical spine and the correlation of radiological patterns to biochemical equivalents in the intervertebral discs. PURPOSE The aim of this pilot study was to (1) measure the GAG content in human cervical discs, (2) to investigate whether a topographic biochemical GAG pattern can be found, and (3) whether there is a correlation between imaging data (X-ray and magnetic resonance imaging [MRI] including delayed gadolinium-enhanced MRI of cartilage [dGEMRIC] as a special imaging technique of cartilage) and the biochemical data. STUDY DESIGN/SAMPLE We conducted a prospective experimental pilot study. PATIENT SAMPLE Only non-responders to conservative therapy were included. All subjects were physically and neurologically examined, and they completed their questionnaires. OUTCOME MEASURES Visual analogue scale neck and arm, Neck Disability Index score, radiological parameters (X-rays, MRI, dGEMRIC), and the content of GAG in the cervical disc were assessed. METHODS After surgical removal of 12 discs, 96 fractions of AF and NP were biochemically analyzed for the GAG content using dimethylmethylene blue assay. RESULTS A quantitative pattern of GAGs in the human cervical disc was identified. There were (1) significantly (p<.001) higher values of GAGs (µg GAG/mg tissue) in the NP (169.9 SD 37.3) compared with the AF (132.4 SD 42.2), and (2) significantly (p<.005) higher values of GAGs in the posterior (right/left: 149.9/160.2) compared with the anterior (right/left: 112.0/120.2) part of the AF. Third, we found in dGEMRIC imaging a significantly (p<.008) different distribution of GAGs in the cervical disc (NP 1083.3 ms [SD 248.6], AF 925.9 ms [SD 137.6]). Finally, we found that grading of disc degeneration in X-ray and MRI was significantly correlated with neither AF- nor NP-GAG content. CONCLUSIONS The GAG content in human cervical discs can be detected in vivo and is subject to a significantly (p<.05) region-specific pattern (AF vs. NP; anterior vs. posterior in the AF). Up to the levels of AF and NP, this is reproducible in MRI in dGEMRIC technique, but not in X-ray or standard MRI sequences. Potentially, the MRI in dGEMRIC technique can be used as a non-invasive in vivo indicator for disc degeneration in the cervical spine.

Intraspinal lumbar juxtaarticular cyst treatment through CT-guided percutaneus induced rupture results in a favorable patient outcome

Juxta-articular cysts are synovial cysts originating from the facet joints or the flava ligaments. If they grow intra-spinally they can compress nervous structures and cause a variety of symptoms. Micro-neurosurgery is usually the treatment of choice. Alternatively to surgical treatment the cyst can be approached and treated with a CT guided percutaneous injection inducing rupture. After fulfilling strict selection criteria twenty patients (25% of all treated lumbar synovial cyst patients), were treated minimally invasive by this method from 2010-2016. The facet joint was punctured under CT guidance and a mixture of a local anesthetic and contrast liquid was injected until the cyst was blasted. The mean follow-up period was 1.1 years (range 2 weeks - 5 years). Fifteen of twenty procedures were successful and cyst rupture was confirmed by CT-scans. Twelve of these fifteen patients experienced a significant improvement of their symptoms and needed no further intervention or surgical procedure up until now, three patients showed no clinical improvement and were treated surgically within one week after cyst rupture. In five patients it was technically not possible to rupture the cyst. These patients were treated microsurgically by cyst resection and dynamic stabilization or fusion procedures. The percutaneus rupture of juxtaarticular cysts has fewer risks and is cost effective compared to microsurgical resection. It may be an alternative to surgical treatment for a selected group of patients. However there are some limitations to the procedure though, such as difficult patient selection, unpredictable outcome or technical problems due to highly degenerated facet joints.

Primary bone tumors of the spine revisited: A 10-year single-center experience of the management and outcome in a neurosurgical department

Objective: To report a large clinical series of primary bone tumors of the spine (PBTS) and review the current concepts of management. Materials and Methods: We retrospectively analyzed a clinical series of PBTS treated over the last decade (2004-2014) in the spine unit of a large European tertiary care center. Every PBTS was identified from an electronic medical-record system. Analysis comprised medical records and clinical imaging. Overall survival and outcome was measured using the Glasgow Outcome Scale (GOS) at six weeks, six months and one year postoperatively. Surgical management and adjuvant/neoadjuvant strategies were analyzed. A thorough review of the current literature was performed. Results: A total of 79 patients were included. Of these, 44 (55.7%) were male. The age ranged from 9 to 90 years (mean 55), and most patients were adults (93.6%). Local pain was the most common symptom and was present in 91.1% of the patients. The majority of the tumors occurred in the thoracic spine (52 patients, 65.8%). Overall 86% (68 patients) of PBTS were classified as malignant and at the time of diagnosis, 7 patients (8.9%) presented with non-spinal metastasis. The most common histologic types were hematopoietic tumors (72.2%), followed by chondrogenic ones (12.7%). Within hematopoietic tumors, plasmacytoma was the most frequent type (49 patients, 62%). In 12 patients (15.2%) recurrences were seen during the follow-up period. Overall mean survival of benign PBTS was 100%, malignant non-hematopoietic PBTS 50% and, malignant hematopoietic PBTS 84% at one year, respectively. At six weeks and one year after the initial surgery, 79% and 54% of the patients presented a GOS >3, respectively. Conclusion: PBTS were almost exclusively seen in adults. Malignant tumors were markedly more frequent than benign tumors, with hematopoietic tumors being the most common type. For PBTS, early surgery is important in order to restore spinal stability and decompress the spinal cord. This allows pain reduction and prevention of neurological deficits.

Pulmonary adenocarcinoma metastasis to a dorsal root ganglion: a case report and review of the literature

IntroductionThe dorsal root ganglion is a rare manifestation of metastatic spread. We report what we believe to be the first case of metastasis of a pulmonary adenocarcinoma to the lumbar dorsal root ganglion. Only four descriptions for different primary tumors spreading to the dorsal root ganglion have been described in the literature so far.Case presentationA 70-year-old Caucasian woman with a four-month history of left-sided lumbar radiculopathy was admitted to our department under the assumption of a herniated lumbar disc. Her past medical history included a pulmonary adenocarcinoma and invasive ductal breast cancer.Lumbar magnetic resonance imaging revealed a space-occupying mass in her left neuroforamen L3-L4 with compression of her L3 nerve root. Neurinoma was taken into account as a differential diagnosis, although not considered typical. Surgery revealed a metastasis of pulmonary adenocarcinoma to her dorsal root ganglion.ConclusionsDorsal root ganglion metastases seem to be extremely rare and can mimic primary local nerve sheath tumors. Therefore, they usually present as incidental findings. Resection should be performed strictly under intraoperative monitoring as tumor spread between the nerve fibers is commonly observed. Metastases should be taken into account in spinal nerve tumors involving the dorsal root ganglion, especially in patients harboring known malignant diseases. The low incidence means that no clear treatment advice can be given. Resection is possible under intraoperative monitoring and relieves neurological symptoms.

Annular closure in lumbar microdiscectomy for prevention of reherniation: a randomized clinical trial

BACKGROUND CONTEXT Patients with large annular defects after lumbar discectomy for disc herniation are at high risk of symptomatic recurrence and reoperation. PURPOSE The present study aimed to determine whether a bone-anchored annular closure device, in addition to lumbar microdiscectomy, resulted in lower reherniation and reoperation rates plus increased overall success compared with lumbar microdiscectomy alone. DESIGN This is a multicenter, randomized superiority study. PATIENT SAMPLE Patients with symptoms of lumbar disc herniation for at least 6 weeks with a large annular defect (6-10 mm width) after lumbar microdiscectomy were included in the study. OUTCOME MEASURES The co-primary end points determined a priori were recurrent herniation and a composite end point consisting of patient-reported, radiographic, and clinical outcomes. Study success required superiority of annular closure on both end points at 2-year follow-up. METHODS Patients received lumbar microdiscectomy with additional bone-anchored annular closure device (n=276 participants) or lumbar microdiscectomy only (control; n=278 participants). This research was supported by Intrinsic Therapeutics. Two authors received study-specific support morethan

The importance of surgery as part of multimodal therapy in rapid progressive primary extraosseous Ewing sarcoma of the cervical intra- and epidural space

10,000 per year, 8 authors received study-specific support less than

Hemodynamic stroke: A rare pitfall in cranio cervical junction surgery

10,000 per year, and 11 authors received no study-specific support. RESULTS Among 554 randomized participants, 550 (annular closure device: n=272; control: n=278) were included in the modified intent-to-treat efficacy analysis and 550 (annular closure device: n=267; control: n=283) were included in the as-treated safety analysis. Both co-primary end points of the study were met, with recurrent herniation (50% vs. 70%, P<.001) and composite end point success (27% vs. 18%, P=.02) favoring annular closure device. The frequency of symptomatic reherniation was lower with annular closure device (12% vs. 25%, P<.001). There were 29 reoperations in 24 patients in the annular closure device group and 61 reoperations in 45 control patients. The frequency of reoperations to address recurrent herniation was 5% with annular closure device and 13% in controls (P=.001). End plate changes were more prevalent in the annular closure device group (84% vs. 30%, P<.001). Scores for back pain, leg pain, Oswestry Disability Index, and health-related quality of life at regular visits were comparable between groups over 2-year follow-up. CONCLUSIONS In patients at high risk of herniation recurrence after lumbar microdiscectomy, annular closure with a bone-anchored implant lowers the risk of symptomatic recurrence and reoperation. Additional study to determine outcomes beyond 2 years with a bone-anchored annular closure device is warranted.