Finite element method evaluates strain of spine metastasis

Chapter Effects Breast and Prostate Cancer Metastases on Lumbar Spine Biomechanics: Rapid In Silico Evaluation, Lorkowski J., Grzegorowska O., Kozień M., Kotela I.In: Advances in Experimental Medicine and Biology (2018). Springer, New York, NY.

Abstract:

Metastases to distant organs are a frequent occurrence in cancer diseases. The skeletal system, especially the spine, is one such organ. The objective of this study was to apply a numerical modeling, using a finite element method (FEM), for the evaluation of deformation and stress in lumbar spine in bone metastases to the spine. We investigated 20 patients (10 women and 10 men) aged 38–81 years. In women, osteolytic lesions in lumbar spine accompanied breast cancer, in men it was prostate cancer. Geometry of FEM models were built based on CT scans of metastatic lumbar spine. We made the models for osteolytic metastases, osteosclerotic metastases, and metastases after surgery. Images were compared. We found a considerable concentration of strain, especially located in the posterior part of the vertebral body. In osteolytic lesions, the strain was located below the vertebral body with metastases. In osteosclerotic lesions, the strain was located in the anterior and posterior parts in and below the vertebral body with metastases. Surgery abolished the pathological strain. We conclude that metastases to the lumbar spine introduce a pathological strain on the lumbar body. The immobilization of the vertebral body around fractures abolished the strain.

Transforaminal lumbar interbody fusion (TLIF): Traditional open versus minimally invasive techniques

transforaminal-lumbar-interbody-fusion

Review article Transforaminal Lumbar Interbody Fusion: Traditional Open Versus Minimally Invasive Techniques, by Lee, Mok, and Patel, in JAAOS 26 (4): 124-131

Abstract:

Recently, minimally invasive spine arthrodesis has gained popularity among spine surgeons. Minimally invasive techniques have advantages and disadvantages compared with traditional open techniques. Comparisons between short-term outcomes of minimally invasive transforaminal interbody fusion and open transforaminal interbody fusion in terms of estimated blood loss, postoperative pain, and hospital length of stay have been well documented and generally favor the minimally invasive technique. However, the advantages of minimally invasive transforaminal interbody fusion must be evaluated in the context of long-term results, such as patient-reported outcomes and the success of arthrodesis. Because the literature is equivocal in identifying the superior technique for successful long-term outcomes, more study is needed. Patient safety, the risk of complications, and the cost of these techniques also must be considered.