Prior to implantation, medical devices are subjected rigorous testing ensure safety and efficacy. A full battery of protocols for implantable spinal may include many steps. Testing biocompatibility is a necessary first step. On selection the material, evaluation should address both biomechanical clinical performance device. Before during mechanical testing, finite element modeling can be used optimize design, predict performance, and, some extent, durability efficacy Following bench-type...

In Brief Study Design. Finite element model of L3–S1 segment and confirmatory cadaveric testing were used to investigate the biomechanical effects a mobile core type artificial disc (Charité disc; DePuy Spine, Raynham, MA) on lumbar spine. Objective. To determine Charité across implanted adjacent segments. Summary Background Data. Biomechanical studies discs that quantify parameters, like load sharing stresses, are sparse in literature, especially for mobile-type designs. addition, there is...

An in vitro human cadaveric biomechanical study.To quantify effects on operated and other levels, including adjacent due to CHARITE disc implantations versus simulated fusions, using follower load the new hybrid test method flexion-extension bilateral torsion.Spinal fusion has been associated with long-term accelerated degeneration at levels. As opposed fusion, artificial discs are designed preserve motion diminish adjacent-level effects.Five fresh lumbar specimens (T12-S1) underwent...

In Brief Study Design. A human cadaveric biomechanical study of lumbar mobility before and after fusion with or without supplemental instrumentation for 5 configurations. Objective. To determine the differences between anterior interbody (ALIF) direct lateral (DLIF) supplementary instrumentation. Summary Background Data. Some prior studies have compared various surgical approaches using same device whereas others investigated stabilizing effect No published performed a side-by-side...

Comparative in vitro, biomechanical study.Compare the effect of rod curvature and material properties on flattening correctional forces.Traditional methods correction for large progressive deformities involve 3-dimensional correction, performed with an attempt to reach a balanced all planes, spinal instrumentation, fusion. Increasing attention transverse plane has developed after introduction segmental pedicle screws into treatment idiopathic scoliosis. Approximation spine (pedicle or hooks)...

Various ball and socket-type designs of cervical artificial discs are in use or under investigation. Many disc claim to restore the normal kinematics spine. What differentiates one type design from another is currently not well understood. In this study, authors examined various clinically relevant parameters using a finite element model C3–C7 spine study effects variations socket designs. Four were placed at C5–C6 level an experimentally validated model. Biomechanical shape (oval vs....

In the normal spine due to its curvature in various regions, C7 plumb line (C7PL) passes through sacrum so that head is centered over pelvis-ball and socket hip joints ankle joints. This configuration leads least muscular activities maintain spinal balance. For any reason like deformity, scoliosis, kyphosis, trauma, and/or surgery this optimal gets disturbed requiring higher activity posture Several parameters thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope...

Object Three types of posterior thoracolumbar implants are in use today: pedicle screws, sublaminar titanium cables, and hooks. The authors conducted a biomechanical comparison these three human cadaveric spines. Methods Spine specimens (T5–12) were harvested, radiographically assessed for fractures or metastases, their bone mineral density (BMD) was measured. Individual vertebrae disarticulated fitted with either bilateral claw longitudinal component each construct consisted 10-cm rods...

Study Design. Randomized Biomechanical Cadaveric Study—Level II. Objective. We aimed to elucidate that placing lateral lumbar interbody cages span the stronger ring apophysis will require increasing loads for failure, decreasing rates of subsidence, regardless bone density or endplate integrity. Summary Background Data. There are several reports regarding and grades cage subsidence when utilizing fusion technique. However, there is limited data on how spanning across can prevent it. Methods....

Cadaveric biomechanical study.To investigate the kinematic response of a stand-alone lateral lumbar interbody cage compared with supplemental posterior fixation either facet or pedicle screws after discectomy.Lateral fusion is promising minimally invasive technique for arthrodesis. The stability placement bilateral remains unclear.A 6-degree freedom spine simulator was used to test flexibility in 7 human cadaveric specimens. Flexion-extension, lateral-bending, and axial-rotation were tested...

In Brief Study Design. Biomechanical laboratory research. Objective. To evaluate the potential for Ultra High Molecular Weight Polyethylene (UHMWPE) wear debris from Charité Artificial Disc. Summary of Background Data. Cases osteolysis artificial discs are extremely rare, but hip and knee studies demonstrate osteolytic clinical concern UHMWPE debris. Standards testing continue to evolve, there few detailed reports disc characterizations. Methods. Implant assemblies were tested 10 million...

Study Design. An investigation of the effects bone density on lumbar spine stability using destabilizing and restabilizing procedures. Objectives. To measure cadaveric vertebral densities computed tomographic scans to correlate measured with in intact state during sequential destabilization restabilization. Summary Background Data. The stabilizing pedicle screw fixation have been widely described. Numerous construct failure mechanisms observed, including loosening osteoporosis. Although...

In Brief Study Design. Fourteen sheep were fused using anterior interbody implants at C2–C3 and C4–C5 followed for 6 months. Objective. To evaluate the effect of absorbable nonabsorbable on fusion rate, cage migration, implant integrity. Summary Background Data. Despite high clinical success rate with metallic plates grafting, complications such as dysphagia, imaging artifacts, revision difficulties exist. Less permanent lower profile could minimize these problems. Methods. Four treatments...

A biomechanical cadaveric study of lumbar spine segments.To compare the immediate stability provided by parallel-shaped and anatomically shaped carbon fiber interbody fusion I/F cages in posterior (PLIF) transforaminal (TLIF) constructs with pedicle screw instrumentation.Few data are available on PLIF TLIF constructs.Twenty human segments were tested flexion-extension (FE) (8 N m flexion, 6 extension), lateral bending (LB) (± m), torsional loading 5 m). Each segment was intact state after...

The goal of this study was to examine the effects absolute/relative loads and frequency on fatigue life titanium stainless steel posterior spinal constructs, determine failure fracture modes. constructs had higher stiffness yield strength than but ultimate static almost equal for both types constructs. Titanium however, exhibited variability In tests, were significantly affected by external load independent. It appears from curves that 500 N can be approximated as endurance limit...