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To establish a chordoma tissue cohort (n = 43) and to correlate localization, size, metastasis, residual disease (R-status), recurrences, histological subtype, matrix content, and Ki-67 proliferation index with patients’ overall survival (OS). We used routine histopathology supplemented by immunohistochemistry. In our patient cohort (median age 69 years, range 17 to 84 years) the median OS was 8.25 years. 24 chordomas were localized in the sacrum, 6 in lumbar vertebrae, 7 in thoracic and cervical vertebrae, 5 were limited to the clivus, and one was localized in the nasal septum. Ten patients had metastases, with pulmonary, nodal, and hepatic involvement. 23 patients had recurrent disease. 23 chordomas were classified as ‘not otherwise specified’ (NOS). Besides NOS, we found the following differentiation patterns: renal cell cancer like in six cases, chondroid in four cases, hepatoid differentiation in three cases, and anaplastic morphology in six cases. Ki-67 index of ≥10 %, presence of metastasis, and the low content of extracellular matrix were statistically linked to poor OS (p

Endoscopic minimally invasive techniques have become an established method of fracture stabilisation in the spine. In view of this fact, anterior stabilisation strategies must be reconsidered, as monosegmental A 3.1 compression fractures are increasingly being stabilised endoscopically from the anterior aspect using minimally invasive techniques. This study investigated the biomechanical necessity of anterior two-point or four-point stabilisation in the instrumentation of mono- and bisegmental fractures. In three biomechanical in vitro studies, burst fracture stabilisation was simulated, and anterior short fixation devices were tested under load with pure moments up to 3.75 Nm to evaluate the biomechanical stabilising characteristics of different kinds of instrumentations in flexion/extension, lateral bending, and axial rotation. Only anterior four-point stabilisation resulted in sufficient primary stability both in mono- and bisegmental instrumentation and therefore represents the standard procedure in open as well as in minimally invasive spinal surgery.

We investigated the osseointegration of solvent-preserved, xenogenous cancellous bone blocks in the treatment of unstable fractures of the thoracolumbar junction. In 22 patients, the anterior repair procedure was performed by thoracoscopy or minimally invasive retroperitoneal surgery. Twenty-two patients had undergone monosegmental anterior fusion and were surveyed prospectively. Solvent-preserved, bovine cancellous bone blocks were used in 11 patients; iliac crest bone graft was used in the others. Follow-up after 12 months included CT scans, which revealed successful osseointegration in eight out of 11 patients who had received autogenous iliac crest bone grafts, while three patients showed a partial integration. There were no graft fragmentations. In patients who had received solvent-preserved, xenogenous cancellous bone blocks, complete osseointegration was achieved at the graft–bone interface in only two out of 11 cases, after 1 year. Partial integration was found in three patients. In view of these results, autogenous iliac crest bone grafts are still the unrivalled standard for defect repair in spinal surgery.

Whether injuries to the alar ligaments could be responsible for complaints of patients having whiplash injury in the upper cervical spine is still controversially discussed. It is known that these ligaments protect the upper cervical spine against excessive lateral bending and axial rotation movements. The objective of the present in vitro study was therefore to examine whether the alar ligaments or any other structures of the cervical spine are damaged in side collisions. In a specially designed acceleration apparatus, six human osteoligamentous cervical spine specimens were subjected to incremental 90 degrees side collisions from the right (1 g, 2 g, 3 g, etc.) until structural failure occurred. A damped pivot table accounted for the passive movements of the trunk during collision, and a dummy head (4.5 kg) ensured almost physiological loading of the specimens. For quantification of functional injuries, the three-dimensional flexibility of the specimens was tested in a spine tester before and after each acceleration. In all six specimens, structural failure always occurred in the lower cervical spine and always affected the facet joint capsules and the intervertebral discs. In four specimens, this damage occurred during the 2 g collision, while in the other two it occurred during the 3 g and 4 g collision, respectively. The flexibility mainly increased in the lower cervical spine (especially in lateral bending to both sides) and, to a minor extent, in axial rotation. In vitro low-speed side collisions caused functional and structural injury to discoligamentous structures of the lower cervical spine, but did not damage the alar ligaments. Since the effects of muscle forces were not taken into account, the present in vitro study reflects a worst-case scenario. Injury thresholds should therefore not be transferred to reality.

A new instrumentation system for ventral stabilization of the spine that can be used for an endoscopic and minimally invasive approach was developed. We describe the implantation technique and report on the first clinical results. This prospective study covers the first 45 patients to undergo this new technique since it was introduced in 1999. In all patients the operation was successfully performed in a completely minimally invasive procedure. Mono- and bisegmental stabilization was performed mainly at the thoracolumbar junction after initial posterior instrumentation in most cases. Lesions varied from fresh/old fractures to metastases (T5–L3). Pre- and postoperative follow-up included clinical examination and radiological visualization via X-ray and computed tomographic scan. Our experience with this minimally invasive procedure demonstrated the feasibility of the method.

This paper compares seven scoring systems to assess their effectiveness in predicting overall survival time in patients with spinal metastases. Sixty-nine patients were evaluated in a prospective fashion using the eight parameters that constitute these different scoring systems. The following preoperative predictive systems were assessed: Tokuhashi score; Sioutos score; Tomita score; Van der Linden score and Bauer score. The basic intention of this paper is interesting. Many scores have been evaluated in the past, but there is a lack of one clinical useful single score. In the clinical daily routine it is always necessary to use more scores with different focuses. Due to this paper the modified Bauer scoring system appears to be the most effective tool. Of the seven parameters assessed location, general condition, number of extraspinal bone metastases, number of visceral metastases, primary tumor, severity of spinal cord palsy and pathological fractures only two, visceral metastases and origin of primary tumor were significant. Nevertheless, to make a recommendation 69 patients included in this work with low numbers concerning each type of primary tumor are not enough to give a significant answer on the initial hypothesis of this paper. Therefore, one must also remain skeptical about drawing definitive conclusions [breast (12), multiple myeloma (10), prostate (7), metastasizing hemangioendothelioma (1), hemangiopericytoma (1), thyroid (1), non-Hodgkin lymphoma (1), kidney (15), uterus (2), tonsil (1), epipharynx (1), femoral synovial sarcoma (1), malign thymoma (1), lung (6), melanoma (2), malignant teratoma (1), liver (1), stomach (1), colon (1), sigma (1), rectum (1), pancreas (1)]. In addition, scores for spinal metastases may furthermore be highly influenced by the effectiveness of existing interdisciplinary therapies present at the time of the creation of the score. However, the prementioned scores have been evaluated in range of two decades. New developments in medical oncology (like tyrosine kinase inhibitor for renal cell carcinoma) and radiotherapeutic fields, as well as in the surgical field (like kyphoplasty) will influence the overall survival time and therefore the existing scores by itself. Due to the increasing numbers of patients suffering on metastases of the spine and the upcoming developments in interdisciplinary therapies for each tumor type, a prospective multicenter study is mandatory. Within a multicenter study, maybe under the patronage of the European Spine Society enough patients could be included, especially considering each primary tumor type. If and only if this is done a current concept with definitive conclusions could be created in my opinion.