4d CT to assess spinal instability in developmental anomaly of posterior arch of atlas

Four-dimensional (4D) CT uniquely allows cinematic visualization of the entirety of joint motion throughout dynamic movement, which can reveal subtle or transient internal joint derangements not evident on static images. As developmental anomalies of the posterior arch can predispose to cervical spinal instability and neurological morbidity, precise assessment of spinal movement during motion is of clinical relevance. We describe the use of 4D-CT in a subject with partial absence of posterior C1 arch. This, to our knowledge, is the first such report. In at-risk individuals, 4D-CT has the potential to enable an assessment of spinal instability with a higher level of clarity and, in this sense, its more routine implementation may be a future direction.

Current concepts from diagnosis to management in Gorham–Stout disease: a systematic narrative review of about 350 cases

Patients with Gorham–Stout disease (GSD) present progressive destruction and resorption of bone. Typical bone-related symptoms include swelling, pain and functional impairment in the region involved. The three aspects of GSD etiopathology are osteoclasts, angiogenesis/lymphangiogenesis and osteoblast function. Multi-targeted pharmacological approach includes innovative options and represent milestones of treatment, sometimes associated with radiotherapy. Surgery is mainly used to treat complications: pathologic/impending fractures, spinal instability or deformities and chylothorax. In this narrative review, we highlight current standards in diagnosis, clinical management and therapeutic strategies.

Percutaneous Endoscopic Interbody Debridement and Fusion for Pyogenic Lumbar Spondylodiskitis: Surgical Technique and the Comparison With Percutaneous Endoscopic Drainage and Debridement

Objective: Surgical treatment of severe infectious spondylodiskitis remains challenging. Although minimally invasive percutaneous endoscopic drainage and debridement (PEDD) may yield good results in complicated cases, outcomes of patients with extensive structural damage and mechanical instability may be unsatisfactory. To address severe infectious spondylodiskitis, we have developed a surgical technique called percutaneous endoscopic interbody debridement and fusion (PEIDF), which comprises endoscopic debridement, bonegraft interbody fusion, and percutaneous posterior instrumentation.Methods: Outcomes of PEIDF in 12 patients and PEDD in 15 patients with infectious spondylodiskitis from April 2014 to July 2018 were reviewed retrospectively. Outcome were compared between 2 kinds of surgical procedures.Results: Patients in PEIDF group had significantly lower rate of revision surgery (8.3% vs. 58.3%), better kyphosis angle (-5.73° ± 8.74 vs. 1.07° ± 2.70 in postoperative; 7.09° ± 7.23 vs. 0.79° ± 4.08 in kyphosis correction at 1 year), and higher fusion rate (83.3% vs. 46.7%) than those who received PEDD.Conclusion: PEIDF is an effective approach for treating infectious spondylodiskitis, especially in patients with spinal instability and multiple medical comorbidities.

Robot for Ligament Tensioning and Assessment of Spinal Stability

Study Design An in vitro human cadaveric biomechanics study. Objective A proof-of-concept study to quantify whether or not differences in segmental mobility associated with spinal instability could be detected by a robotic distraction system. Methods Testing was performed in fresh human cadaveric tissue. A prototype Robotic Middle Column Distractor was attached unilaterally to the pedicles of L3-4. Distraction forces up to 150 N were applied first in the intact state, and following discectomy of L3-4. Motions were recorded by time-indexed visual and fluoroscopic images, and analyzed to measure actual motions achieved. Functions of the robot unit were monitored during the procedure and evaluated qualitatively. Results A difference of 2.5 mm in z-axis motion was detected at 150 N load between the intact and post-discectomy states. The robot coupled with the image analysis method was able to clearly detect the difference between the intact (“stable”) and post-discectomy (“unstable”) spine. Data analysis of fluoroscopic images taken during the procedure showed greater motion than perceived by the investigators from qualitative review of visual data. All monitored robot functions performed within design parameters without error. Conclusion The study demonstrates the feasibility and utility of utilizing an intraoperative robotic distractor to measure the amount of spinal mobility present at a level. This could lead to an important clinical tool for both diagnostic functions as well as operative assist functions.

Fracture Risk Evaluation of Bone Metastases: A Burning Issue

Major progress has been achieved to treat cancer patients and survival has improved considerably, even for stage-IV bone metastatic patients. Locomotive health has become a crucial issue for patient autonomy and quality of life. The centerpiece of the reflection lies in the fracture risk evaluation of bone metastasis to guide physician decision regarding physical activity, antiresorptive agent prescription, and local intervention by radiotherapy, surgery, and interventional radiology. A key mandatory step, since bone metastases may be asymptomatic and disseminated throughout the skeleton, is to identify the bone metastasis location by cartography, especially within weight-bearing bones. For every location, the fracture risk evaluation relies on qualitative approaches using imagery and scores such as Mirels and spinal instability neoplastic score (SINS). This approach, however, has important limitations and there is a need to develop new tools for bone metastatic and myeloma fracture risk evaluation. Personalized numerical simulation qCT-based imaging constitutes one of these emerging tools to assess bone tumoral strength and estimate the femoral and vertebral fracture risk. The next generation of numerical simulation and artificial intelligence will take into account multiple loadings to integrate movement and obtain conditions even closer to real-life, in order to guide patient rehabilitation and activity within a personalized-medicine approach.

Case Report: Spinal Stabilization Surgery Using a Novel Custom-Made Titanium Fixation System for the Spinal Instability Caused by Vertebral Malformation in a Dog

A 2-year-old Maltese was presented with wobbly gait of the pelvic limbs. Based on imaging examinations, a diagnosis of congenital malformation at T5–T8 and severe kyphosis causing spinal cord compression at T6–T7 was made. Dorsal laminectomy and stabilization of T6 and T7 vertebrae were performed. As the size of the vertebrae was small and they were severely deformed, novel custom-made titanium implants were used for spinal stabilization. Clinical signs were resolved 2 weeks after surgery. Although radiographic examination 373 days after surgery showed slight loosening of implants, post-operative course remained uneventful. This report describes the use of novel custom-made titanium implants for spinal fixation surgery in a dog.

Disc Degeneration in Direct Injury or Instability Models Share Common Metabolic Pathways

Introduction: Disc degeneration is the central component involved in numerous common spinal pathologies. Degenerative disc disease affects millions of people every year, yet the mechanisms driving degeneration remain poorly understood. Previous work to date has shown that high levels of intracellular lactate seem to be involved in driving this pathology once thought to be purely mechanical. Here, we present a series of studies utilizing mouse models of mechanical injuring or loading of the intervertebral disc (IVD), with a goal of better defining the role of lactate and lactate transport in degenerative disc disease. Methodology: Four models of disc degeneration were studied: (i) lumbar disc poke, (ii) tail disc poke, (iii) spinal instability, and (iv) sham. Female mice (C57BL/6J, n = 30) were randomly assigned to one group. In group 1, a retroperitoneal approach exposed the IVD of the lumbar spine, and a 27G needle was used to injure the disc. In group 2, the needle was inserted in the tail IVD. In group 3, lumbar instability was induced by resection of bilateral facet joints and supraspinous/interspinous ligaments. In group 4, a sham was used for each. The mice were euthanized at two, four, and eight weeks. IVD was evaluated by histological and immunofluorescence analysis. RNA extraction from disc tissue was analyzed with QPCR. Result: Sham mice did not have significant disc degeneration. In groups 1 and 2, the degenerative process at two, four, and eight weeks was characterized by loss of nucleus pulposus (NP) cells and the gradual increase in matrix components in NP. The distinction between NP and annulus fibroids (AF) or endplate cartilage is lost. There was increased expression of collagen X and MMP13 in the NP, and MCT4 was decreased, while MCT3 was increased. In group 3, disorder of the AF was evident in the first two weeks post surgery, the collapsed disc space and the NP area gradually lessened. The proteoglycan detected in the inner layer of AF and the periphery of NP decreased after eight weeks. There was increase in type X collagen and MMP13 in the inner AF and NP. Conclusion: Our results demonstrate a common molecular pathway whereby discs degenerate after direct injury or becoming unstable. In our model, there was a rapid degeneration of the IVD in mice who exhibit up- and downregulation of several important markers. Importantly, MCT4 was downregulated, while MCT3 was upregulated. While MCT4 was associated with lactate exportation, and its loss resulted in elevated intracellular lactate and disc degradation, MCT3 is rarely expressed and may be acting as a rescue lactate transporter.