Augmented reality for minimally invasive spinal surgery

BackgroundAugmented reality (AR) is an emerging technology that can overlay computer graphics onto the real world and enhance visual feedback from information systems. Within the past several decades, innovations related to AR have been integrated into our daily lives; however, its application in medicine, specifically in minimally invasive spine surgery (MISS), may be most important to understand. AR navigation provides auditory and haptic feedback, which can further enhance surgeons’ capabilities and improve safety.PurposeThe purpose of this article is to address previous and current applications of AR, AR in MISS, limitations of today's technology, and future areas of innovation.MethodsA literature review related to applications of AR technology in previous and current generations was conducted.ResultsAR systems have been implemented for treatments related to spinal surgeries in recent years, and AR may be an alternative to current approaches such as traditional navigation, robotically assisted navigation, fluoroscopic guidance, and free hand. As AR is capable of projecting patient anatomy directly on the surgical field, it can eliminate concern for surgeon attention shift from the surgical field to navigated remote screens, line-of-sight interruption, and cumulative radiation exposure as the demand for MISS increases.ConclusionAR is a novel technology that can improve spinal surgery, and limitations will likely have a great impact on future technology

Lumbar Degenerative Disc Disease: Current and Future Concepts of Diagnosis and Management

Low back pain as a result of degenerative disc disease imparts a large socioeconomic impact on the health care system. Traditional concepts for treatment of lumbar disc degeneration have aimed at symptomatic relief by limiting motion in the lumbar spine, but novel treatment strategies involving stem cells, growth factors, and gene therapy have the theoretical potential to prevent, slow, or even reverse disc degeneration. Understanding the pathophysiological basis of disc degeneration is essential for the development of treatment strategies that target the underlying mechanisms of disc degeneration rather than the downstream symptom of pain. Such strategies ideally aim to induce disc regeneration or to replace the degenerated disc. However, at present, treatment options for degenerative disc disease remain suboptimal, and development and outcomes of novel treatment options currently have to be considered unpredictable

Injectable bioartificial myocardial tissue for large-scale intramural cell transfer and functional recovery of injured heart muscle

ObjectivesMost tissue-engineering approaches to restore injured heart muscle result in distortion of left ventricular geometry. In the present study we suggest seeding embryonic stem cells in a liquid matrix for myocardial restoration.MethodsUndifferentiated green fluorescent protein–labeled mouse embryonic stem cells (2 × 106) were seeded in Matrigel (B&D, Bedford, Mass). In a Lewis rat heterotopic heart transplant model an intramural left ventricular pouch was fashioned after ligation of the left anterior descending coronary artery. The liquid mixture (0.125 mL) was injected in the resulting infarcted area within the pouch and solidified within a few minutes after transplantation (37°C). Five recipient groups were formed: transplanted healthy hearts (group I), infarcted control hearts (group II), matrix recipients alone (group III), the study group that received matrix plus cells (group IV), and a group that received embryonic stem cells alone (group V). After echocardiography 2 weeks later, the hearts were harvested and stained for green fluorescent protein and cardiac muscle markers (connexin 43 and α-sarcomeric actin).ResultsThe graft formed a sustained structure within the injured area and prevented ventricular wall thinning. The inoculated cells remained viable and expressed connexin 43 and α-sarcomeric actin. Fractional shortening and regional contractility were better in animals that received bioartificial tissue grafts compared with control animals (infarcted, matrix only, and embryonic stem cells only: group I, 17.0% ± 3.5%; group II, 6.6% ± 2.1%; group III, 10.3% ± 2.2%; group IV, 14.5% ± 2.5%; and group V, 7.8% ± 1.8%).ConclusionsLiquid bioartificial tissue containing embryonic stem cells constitutes a powerful new approach to restoring injured heart muscle without distorting its geometry and structure

Anterior cervical osteotomy of diffuse idiopathic skeletal hyperostosis lesions with computer‐assisted navigation surgery: A case report

Key Clinical Message Diffuse idiopathic skeletal hyperostosis (DISH) involves spine ligament ossification. Computer‐assisted navigation (CAN) effectively aids complex surgeries, such as anterior cervical osteotomy, to alleviate progressive DISH‐related dysphagia. Abstract We describe a 68‐year‐old man with sudden onset dysphagia to both solids and liquids. Radiographic Imaging revealed DISH lesions from C2 down to the thoracic spine. The patient was successfully treated with CAN anterior osteotomy and resection of DISH lesions from C3–C6 and had complete symptom relief within 2 weeks post‐operatively

Novel Injectable Bioartificial Tissue Facilitates Targeted, Less Invasive, Large-Scale Tissue Restoration on the Beating Heart After Myocardial Injury

Background— Implantation of bioartificial patches distorts myocardial geometry, and functional improvement of the recipient heart is usually attributed to reactive angiogenesis around the graft. With the liquid bioartificial tissue compound used in this study, we achieved targeted large-scale support of the infarcted left ventricular wall and improvement of heart function. Methods and Results— A liquid compound consisting of growth factor-free Matrigel and 10 6 green fluorescent protein (GFP)-positive mouse (129sv) embryonic stem cells (ESCs) was generated and injected into the area of ischemia after ligation of the left anterior descending artery in BALB/c mice (group I). Left anterior descending artery-ligated mice (group II) and mice with Matrigel (group III) or ESC treatment alone (group IV) were used as the control groups (n=5 in all groups). The hearts were harvested for histology 2 weeks later after echocardiographic assessment with a 15-MHz probe. The liquid injectable tissue solidified at body temperature and retained the geometry of the infarcted lateral wall. Immunofluorescence stains revealed voluminous GFP grafts. The quality of restoration (graft/infarct area ratio) was 45.5±10.8% in group I and 29.1±6.7% in group IV ( P =0.034). ESCs expressed connexin 43 at intercellular contact sites. The mice treated with the compound had a superior heart function compared with the controls ( P <0.0001 by ANOVA/Bonferroni test; group I: 27.1±5.4, group II:11.9±2.4, group III:16.2±2.8, group IV: 19.1±2.7). Conclusions— Injectable bioartificial tissue restores the heart’s geometry and function in a targeted and nondistorting fashion. This new method paves the way for novel interventional approaches to myocardial repair, using both stem cells and matrices

A Comparative Study of Lateral Lumbar Interbody Fusion and Posterior Lumbar Interbody Fusion in Degenerative Lumbar Spondylolisthesis

Study DesignLevel 4 retrospective review.PurposeTo compare the radiographic and clinical outcomes between posterior lumbar interbody fusion (PLIF) and lateral lumbar interbody fusion (LLIF) with posterior segmental spinal instrumentation (SSI) for degenerative lumbar spondylolisthesis.Overview of LiteratureBoth PLIF and LLIF have been performed for degenerative spondylolisthesis with good results, but no study has directly compared these two techniques so far.MethodsThe electronic medical and radiographic records of 78 matched patients were analyzed. In one group, 39 patients underwent PLIF with SSI at 41 levels (L3-4/L4-5), while in the other group, 39 patients underwent the LLIF procedure at 48 levels (L3-4/L4-5). Radiological outcomes such as restoration of disc height and neuroforaminal height, segmental lumbar lordosis, total lumbar lordosis, incidence of endplate fracture, and subsidence were measured. Perioperative parameters were also recorded in each group. Clinical outcome in both groups was assessed by the short form-12, Oswestry disability index and visual analogue scale scores. The average follow-up period was 16.1 months in the LLIF group and 21 months in the PLIF group.ResultsThe restoration of disc height, foraminal height, and segmental lumbar lordosis was significantly better in the LLIF group (p<0.001). The duration of the operation was similar in both groups, but the average blood loss was significantly lower in the LLIF group (p<0.001). However, clinical outcome scores were similar in both groups.ConclusionsSafe, effective interbody fusion can be achieved at multiple levels with neuromonitoring by the lateral approach. LLIF is a viable treatment option in patients with new onset symptoms due to degenerative spondylolisthesis who have had previous lumbar spine surgery, and it results in improved sagittal alignment and indirect foraminal decompression

Allopurinol/uricase and ibuprofen enhance engraftment of cardiomyocyte-enriched human embryonic stem cells and improve cardiac function following myocardial injury

Objective: A major limitation of stem cell transfer is early donor-cell death. Here, we seek to enhance myocardial repair following injury through transplantation of cardiomyocyte-enriched human embryonic stem cells (hESC) and recipient treatment with cytoprotective (allopurinol + uricase) and anti-inflammatory (ibuprofen) agents. Methods: We injected 106 (15% hESC-derived cardiomyocytes) green fluorescent protein (GFP+) hESC in the infarcted area following left anterior descending artery (LAD)-ligation in SCID-beige mice. In Group I, 1.6 mg allopurinol and 0.2 mg of uricase were injected i.p. for 3 days prior to cell transplantation. In Group II, 0.35 mg/ml of ibuprofen were added to the drinking water before and after cell implantation. In Group III, the LAD was ligated and allopurinol/uricase was administered without cell treatment. In Group IV, ibuprofen was added to the drinking water and the LAD was ligated without additional cell treatment. In Group V, only cells were transplanted. Group VI involved infarcted controls and Group VII involved sham-operated mice (all groups: n = 5). We evaluated heart function (ejection fraction (EF)) by MRI (4.7 T) 3 weeks later. The hearts were harvested for histology. Results: Differentiated hESC formed clusters and expressed α-sarcomeric actin and Connexin 43. Cell treatment improved heart function, which was best in the ibuprofen- and allopurinol-treated groups (+cell transfer), compared to the infarcted controls [EF: Group I: 76.6 ± 8.6%, Group II: 78.6 ± 7.3%, Group III: 58.1 ± 5.7%, Group IV: 53.9 ± 5.2%, Group V: 57.7 ± 7.5%, Group VI: 43.5 ± 4.3%, and Group VII: 66.3 ± 7.8%]. We did not observe tumors in any group. Conclusions: Allopurinol/uricase and ibuprofen enhance differentiated hESC-engraftment and myocardial restoration following transplantation into the injured heart. © 2005 Elsevier B.V. All rights reserved