Balloon kyphoplasty and additional anterior odontoid screw fixation for treatment of unstable osteolytic lesions of the vertebral body C2: a case series

Abstract Background Unstable osteolytic lesions of the occipitocervical junction are rare and may occur in hematological malignancy or vertebral hemangioma, among others. Different case reports have been published about vertebroplasty for treatment of spinal metastases of the upper cervical spine. Only few cases concern balloon kyphoplasty of C2. We present a consecutive case series including four patients with an osteolytic lesion of the dens axis and describe a technical note for balloon kyphoplasty of C2 and an additional anterior odontoid screw fixation. Methods Four consecutive patients with an osteolytic lesion of the vertebral body of C2 were treated by anterior balloon kyphoplasty and additional anterior odontoid screw fixation of the dens axis. The radiological imaging showed a lytic process of the vertebral body C2 with no vertebral collapse but involvement of more than 50% of the vertebral body in all patients. Results Two cases of potentially unstable osteolytic lesions of C2 by myeloma, one case with metastatic osteolytic lesion of C2 by adenocarcinoma of the colon and one patient with vertebral hemangioma located in C2 were presented to our clinic. In all cases, surgical treatment with an anterior balloon kyphoplasty of C2 and an additional anterior, bicortical odontoid screw placement was performed. Control x-rays showed sufficient osteosynthesis and cement placement in the vertebral body C2. Discussion Anterior balloon kyphoplasty and anterior odontoid screw placement is a safe treatment option for large osteolytic lesions of C2. The additional odontoid screw placement has the advantage of providing more stabilization and may prevent late complications, like odontoid fractures. For patients with potentially unstable or large osteolytic lesions of the dens without spinal cord compression or neurological symptoms we recommend the placement of an anterior odontoid screw when performing a balloon kyphoplasty. Level of evidence: - IV: retrospective or historical series

Surgical Treatment Strategies for Pyogenic Spondylodiscitis of the Thoracolumbar Spine

Background Despite advances, the morbidity and mortality rates of patients with spondylodiscitis remains high, with an increasing incidence worldwide. Although conservative therapy has progressed, several cases require surgical intervention. However, the indication and opportunities for surgical treatment are still disputable. Methods In a joint consensus, the members of the `Spondylodiscitis' working group of the Spine Section of the German Society for Orthopaedics and Trauma Surgery considered current literature, particularly the newly published S2k guideline of the AWMF, and examined the surgical indications and treatment strategies for thoracolumbar spondylodiscitis. Results Surgical intervention for spondylodiscitis is only required in a small percentage of patients. In studies comparing conservative and surgical therapies, most patients benefitted from surgery, regardless of the surgical technique selected. Presently, the standard procedure is a combined dorsoventral approach, in which a monolateral attempt should always be made. The choice of material (PEEK, titanium) for ventral support does not influence the clinical result

Biomechanical comparative study of midline cortical vs. traditional pedicle screw trajectory in osteoporotic bone

Abstract Introduction In lumbar spinal stabilization pedicle screws are used as standard. However, especially in osteoporosis, screw anchorage is a problem. Cortical bone trajectory (CBT) is an alternative technique designed to increase stability without the use of cement. In this regard, comparative studies showed biomechanical superiority of the MC (midline cortical bone trajectory) technique with longer cortical progression over the CBT technique. The aim of this biomechanical study was to comparatively investigate the MC technique against the not cemented pedicle screws (TT) in terms of their pullout forces and anchorage properties during sagittal cyclic loading according to the ASTM F1717 test. Methods Five cadavers (L1 to L5), whose mean age was 83.3 ± 9.9 years and mean T Score of -3.92 ± 0.38, were dissected and the vertebral bodies embedded in polyurethane casting resin. Then, one screw was randomly inserted into each vertebra using a template according to the MC technique and a second one was inserted by freehand technique with traditional trajectory (TT). The screws were quasi-static extracted from vertebrae L1 and L3, while for L2, L4 and L5 they were first tested dynamically according to ASTM standard F1717 (10,000 cycles at 1 Hz between 10 and 110 N) and then quasi-static extracted. In order to determine possible screw loosening, there movements were recorded during the dynamic tests using an optical measurement system. Results The pull-out tests show a higher pull-out strength for the MC technique of 555.4 ± 237.0 N compared to the TT technique 448.8 ± 303.2 N. During the dynamic tests (L2, L4, L5), 8 out of the 15 TT screws became loose before completing 10,000 cycles. In contrast, all 15 MC screws did not exceed the termination criterion and were thus able to complete the full test procedure. For the runners, the optical measurement showed greater relative movement of the TT variant compared to the MC variant. The pull-out tests also revealed that the MC variant had a higher pull-out strength, measuring at766.7 ± 385.4 N, while the TT variant measured 637.4 ± 435.6 N. Conclusion The highest pullout forces were achieved by the MC technique. The main difference between the techniques was observed in the dynamic measurements, where the MC technique exhibited superior primary stability compared to the conventional technique in terms of primary stability. Overall, the MC technique in combination with template-guided insertion represents the best alternative for anchoring screws in osteoporotic bone without cement

Total spine magnetic resonance imaging for detection of multifocal infection in pyogenic spondylodiscitis: a retrospective observational study

Background!#!Due to the unspecific symptoms of spondylodiscitis (SpD), an early radiological examination is necessary. However, controversially discussed is the need for magnetic resonance imaging of the entire spine to exclude multisegmental infections and to determine the required surgical interventions. The aims of this study were to assess the incidence of multilevel non-contiguous pyogenic SpD and compare comorbidities, pain symptoms, and subsequent surgical strategies between unifocal (uSpD) and multifocal (mSpD) SpD.!##!Methods!#!We retrospectively evaluated the data of patients with confirmed, surgically treated, pyogenic SpD who had received a total spine MRI in a single spine center between 2016 and 2018. MRI findings were classified according to Pola-classification and demographics, duration of clinical symptoms (pain and neurology) and Charlson Comorbidity-Index (CCI) results were compared between uSpD und mSpD groups. Surgical therapy was evaluated in patients with mSpD.!##!Results!#!uSpD was detected by MRI in 69 of 79 patients (87%). Of these, mSpD was detected in 10 patients (13%) with 21 infected segments (cervical and/ or thoracic and/ or lumbar region). Age and CCI were similar between uSpD and mSpD and 24 of all SpD regions were clinically unapparent. All patients with uSpD were treated operatively. In seven patients with mSpD, all infected levels of the spine were treated surgically in a one-stage procedure; one patient had a two-stage procedure and one patient had surgery at the lumbar spine, and an additional infected segment of the upper thoracic spine was treated conservatively. One patient died before a planned two-stage procedure was performed.!##!Conclusions!#!Due to mSpD being found in approximately 13% of SpD cases, and considering the risk of overlooking an mSpD case, MRI imaging of the total spine is recommended. The detection of multiple infection levels can have an impact on the therapeutic strategy chosen

Analysis of a Unilateral Bridging Cage for Lumbar Interbody Fusion: 2-Year Clinical Results and Fusion Rate with a Focus on Subsidence

Purpose: The aim of this study was to evaluate the biomechanical stability and the clinical and radiographic outcomes in patients undergoing transforaminal lumbar interbody fusion (TLIF) using an oblique bridging cage with a particular focus on subsidence. Methods: Finite element models were developed to compare the biomechanics of the oblique cage with conventional posterior lumbar interbody fusion and banana-shaped cages with TLIF. Additionally, a retrospective review of a prospective collected database was performed to investigate the clinical and radiologic results with a focus on the subsidence rate using an oblique polyetheretherketone (PEEK) cage with a bicortical load-bearing design. We included 87 patients with degenerative pathologic conditions of the lumbar spine who underwent TLIF. The clinical outcome was assessed using the Oswestry Low Back Pain Disability Questionnaire and the visual analogue scale. Fusion and subsidence rates were assessed radiographically. Results: The finite element models showed no differences in stability on compression or extension/flexion. The oblique cage differed in terms of the location of the maximal stresses. A total of 105 levels were fused. The level at which fusion was most frequently performed was L4–L5 (59%). The fusion rate was 93.2% after 24 months. Subsidence was found at 4 levels after the last follow-up visit (3.9%). Overall clinical outcome improvement was achieved after 24 months. Conclusion: Regarding fusion, the use of an oblique PEEK cage with a cortical load-bearing design provided highly satisfactory clinical and radiologic results after 2 years. A review of the literature suggests a lower rate of cage subsidence after lumbar interbody fusion using bridging cages rather than single cages