Paraspinal-approach transforaminal lumbar interbody fusion for the treatment of lumbar foraminal stenosis.

Object: Foraminal stenosis is a common cause of lumbar radicular symptoms. Recognition of the dynamic pathology, as well as the static anatomical changes, is important to achieving successful surgical outcomes. Excessive facet and anulus removal leads to subsequent disc space narrowing and/or segmental instability, which can cause poor results after decompressive surgery.

Bone bonding bioactivity of Ti metal and Ti-Zr-Nb-Ta alloys with Ca ions incorporated on their surfaces by simple chemical and heat treatments.

Ti15Zr4Nb4Ta and Ti29Nb13Ta4.6Zr, which do not contain the potentially cytotoxic elements V and Al, represent a new generation of alloys with improved corrosion resistance, mechanical properties, and cytocompatibility. Recently it has become possible for the apatite forming ability of these alloys to be ascertained by treatment with alkali, CaCl2, heat, and water (ACaHW).

Outcome of Surgical Treatment for Metastatic Vertebra Bone Tumor in Advanced Lung Cancer.

BACKGROUND: Spinal metastases of patients with advanced stage lung cancer are an important target for palliative therapy, because their incidence is high, and they often cause severe symptoms and worsen the quality of life. Surgery is one of the most effective treatment options, but the indication of surgery is unclear as the procedure is invasive and patients with spinal metastasis have a rather short life expectancy. Furthermore, there have been few studies that have focused on lung cancer with poor prognosis.

Advantages of the paraspinal muscle splitting approach in comparison with conventional midline approach for s1 pedicle screw placement.

Study Design: A retrospective comparative study of the S1 pedicle screw (S1PS) position obtained using 2 surgical approaches.

Objective: To determine whether the paraspinal approach leads to more medially oriented placement of the S1PS compared with the midline approach.

Summary Of Background Data: To obtain a stronger as well as safer fixation of the S1PS, medially oriented screw placement is very important.

Neck muscle strength before and after cervical laminoplasty: relation to axial symptoms.

Study Design: A prospective study to investigate serial changes in neck muscle strength before and after cervical laminoplasty.

Objectives: To examine the correlation between neck muscle strength and axial symptoms, and to clarify the risk factors for axial symptoms.

Summary Of Background Data: Axial symptoms are common complications after posterior cervical spinal surgery.

Reinforcement of tendon attachment to bioactive porous titanium by BMP-2-induced ectopic bone formation.

Achieving a firm attachment between a tendon and a metal remains a major challenge in orthopedic surgery. In this study, we developed a simple model for evaluating the strength of this attachment using bioactive porous titanium, and confirmed whether bone morphogenic protein-2 (BMP-2) can be a help in achieving a firm attachment by ectopic bone formation. Rectangular plate-shaped implants were soak-loaded with BMP-2 (B+ group) and were implanted within the patellar tendon of a rabbit.

Navigated anterior approach to the upper cervical spine after occipitocervical fusion.

Study Design: Technical note.

Objective: To introduce the application of navigation system with software for brain surgery to the upper cervical spine of patients who have previously had occipitocervical (O-C) fusion.

Summary Of Background Data: The anterior approach to the spine using a navigation system with software for spine surgery is difficult because the registration tends to be inaccurate.

The value of palliative surgery for metastatic spinal disease: satisfaction of patients and their families.

Background Context: Although there have been several studies in which the surgical outcomes were evaluated by pain reduction or neurological improvement, there have been few studies focused on the quality of life (QOL) of the patients after the surgery. We considered that the most important consideration in palliative surgery was to respect the wishes of patients and their families, which are likely to be influenced by the patients' QOL for their limited life span.

Purpose: To evaluate the value of palliative surgery for spinal metastasis and to identify the factors predicting satisfaction of patients and their families after the surgery.

Subaxial subluxation after atlantoaxial transarticular screw fixation in rheumatoid patients.

The most common cervical abnormality associated with rheumatoid arthritis (RA) is atlantoaxial subluxation, and atlantoaxial transarticular screw fixation has proved to be one of the most reliable, stable fixation techniques for treating atlantoaxial subluxation. Following C1-C2 fixation, however, subaxial subluxation reportedly can bring about neurological deterioration and require secondary operative interventions. Rheumatoid patients appear to have a higher risk, but there has been no systematic comparison between rheumatoid and non-rheumatoid patients.

O-C2 angle as a predictor of dyspnea and/or dysphagia after occipitocervical fusion.

Study Design: A retrospective clinical study.

Objective: To confirm the impact of the O-C2 angle on dyspnea and dysphagia after posterior occipitocervical (O-C) fusion.

Summary Of Background Data: Dyspnea and dysphagia are complications of posterior O-C fusion with malalignment, and may be prolonged or occasionally serious.

Double-door cervical laminoplasty with the use of suture anchors: technical note.

Study Design: Technical note.

Objective: To introduce a new simple technique using suture anchors to stabilize the elevated laminae in double-door cervical laminoplasty.

Summary Of Background Data: Double-door cervical laminoplasty is a well-recognized procedure for the treatment of cervical spinal myelopathy.

Is rheumatoid arthritis a risk factor for a high-riding vertebral artery?

Study Design: A retrospective comparative study on the morphologic characteristics of the axis in patients with or without rheumatoid arthritis (RA).

Objective: To compare the morphologic risk of vertebral artery (VA) injury during atlantoaxial transarticular screw fixation between patients with or without RA.

Summary Of Background Data: VA injury is a potentially serious complication during atlantoaxial transarticular screw fixation.

Stand-alone interbody cage versus anterior cervical plate for treatment of cervical disc herniation: sequential changes in cage subsidence.

Anterior cervical discectomy and fusion with an autogenous iliac bone graft is the gold standard treatment for cervical disc herniation. However, autologous bone grafts obtained from the anterior iliac crest are associated with significant donor-site morbidity and complications. To decrease bone graft-related problems, several types of interbody fusion cage have been developed and are used widely in clinical practice.

Atlantoaxial transarticular screw fixation with posterior wiring using polyethylene cable: facet fusion despite posterior graft resorption in rheumatoid patients.

Study Design: A comparative retrospective study on the posterior graft union and the facet fusion in atlantoaxial transarticular screw fixation.

Objective: To evaluate the posterior graft union and the facet fusion in atlantoaxial transarticular screw fixation when a polyethylene (PE) cable was used in rheumatoid and nonrheumatoid patients.

Summary Of Background Data: In atlantoaxial transarticular screw fixation, metal wires or cables for posterior bone graft fixation can cause intraoperative or delayed spinal cord compression.

Rheumatoid arthritis as a risk factor for a narrow C-2 pedicle: 3D analysis of the C-2 pedicle screw trajectory.

Object: Vertebral artery (VA) injury is a potentially serious complication of C-2 pedicle screw (PS) fixation. Although this surgery is frequently performed in patients with rheumatoid arthritis (RA), few studies have compared the risk of VA injury in patients with and without RA. In this study, the authors compare the morphological risk of VA injury relating to C-2 PS fixation in patients with and without RA.

EP4 agonist accelerates osteoinduction and degradation of beta-tricalcium phosphate by stimulating osteoclastogenesis.

Porous beta-tricalcium phosphate (TCP) has been known to have osteoinductive potential in ectopic site implantation in canine models without the use of osteoinductive substances or cell transplantation. Prostaglandin E2 receptors, particularly EP4, are known to play an important role in osteogenesis. EP4 agonists have been demonstrated to have positive effects on bone remodeling and bone morphogenic protein-induced ectopic bone formation in rodent models.

Treatment of upper cervical spine involvement in rheumatoid arthritis patients.

The cervical spine, especially the upper cervical spine, is a common focus of destruction by rheumatoid arthritis (RA). Because of its potentially debilitating and life-threatening sequelae, cervical spine involvement remains a priority in the diagnosis and treatment of RA. Many studies show that early surgical intervention gives a more satisfactory outcome.

Vertebral artery injury during cervical spine surgery: a survey of more than 5600 operations.

Study Design: Retrospective survey.

Objective: To clarify the present incidence and management of iatrogenic vertebral artery injury (VAI) during cervical spine surgery.

Summary Of Background Data: VAI is a rare complication of cervical spine surgery, but it may be catastrophic.

En bloc total vertebrectomy for lung cancer invading the spine.

Introduction of spinal surgery into lung cancer operations has made extensive operations feasible with an acceptable long-term survival. We report our successful experience of en bloc total vertebrectomy for lung cancer invading the spine. A 49-year-old man was found to have squamous cell carcinoma of the posterior apex of the right lung with an invasion of the body of the second and third thoracic vertebra.

Enhancement of bone-bonding ability of bioactive titanium by prostaglandin E2 receptor selective agonist.

Systemic administration of prostaglandin E2 receptor (EP4) selective agonist increases both bone formation and resorption, and consequently leads to an increase in bone mass. Although previous studies have reported that EP4 agonist enhanced bone remodeling and fracture healing, it was not known if EP4 agonist activates the bone-biomaterial interface. Bioactive titanium prepared by chemical and thermal treatment can bond to living bone and is suitable for use in clinical applications in cementless fixation devices.

Expression of vascular cell adhesion molecule-1 indicates the differentiation potential of human bone marrow stromal cells.

Bone marrow stromal cells (BMSCs) are a mixture of cells differing in differentiation potential including mesenchymal stem cells, and so far no CD antigens were found to be predictable for the differentiation property of each BMSC. Here we attempted to isolate differentiation-associated CD antigens using 100 immortalized human BMSC (ihBMSC) clones. Among 13 CD antigens analyzed, only CD106/Vascular cell adhesion molecule-1 (VCAM-1) showed a clear correlation with the differentiation potential of each clone; CD106-positive ihBMSC clones were less osteogenic and more adipogenic than CD106-negative clones.

A porous bioactive titanium implant for spinal interbody fusion: an experimental study using a canine model.

Object: Porous biomaterials with adequate pore structure and appropriate mechanical properties are expected to provide a new generation of devices for spinal interbody fusion because of their potential to eliminate bone grafting. The purpose of this study was to evaluate the fusion characteristics of porous bioactive titanium implants using a canine anterior interbody fusion model.

Methods: Porous titanium implants sintered with volatile spacer particles (porosity 50%, average pore size 303 microm, compressive strength 116.

Palliative dual iliac screw fixation for lumbosacral metastasis. Technical note.

Spinal fixation for destructive metastatic lesions at the lumbosacral junction is challenging because of the large and unique load-bearing characteristics present. In particular, caudal fixation is difficult in cases of sacral destruction because of insufficient S-1 pedicle screw anchorage. The authors describe their surgical technique for secure iliac screw placement and the clinical results obtained in five patients with metastatic spinal disease.