Clinical performance of an elastomeric lumbar disc replacement: Minimum 12 months follow-up.

Background: Elastomeric disc replacements have been developed to restore normal shock absorption and physiologic centers of rotation to the degenerated disc. The Physio-L Artificial Lumbar Disc is an elastomeric disc which uses a compliant polycarbonate-polyurethane core with enhanced endurance properties. The objective of this study was to evaluate the safety and efficacy of the Physio-L through a 12-month follow-up period in a prospective, nonrandomized clinical trial.

Load balance in total knee arthroplasty: an in vitro analysis.

Background: One of the goals of total knee arthroplasty (TKA) is to balance the loads between the compartments of the knee. An instrumented load cell that measures compartment loads in real time is utilized to evaluate conventional, qualitative methods of achieving this balance.

Methods: TKA was performed on 10 cadaveric knees.

Biomechanical comparison of intramedullary nail and blade plate fixation for tibiotalocalcaneal arthrodesis.

Objective: Tibiotalocalcaneal arthrodesis is used to manage severe bone loss, arthritis, and/or instability. The goal is to relieve pain through a stable, well-aligned hindfoot and ankle. The purpose of this study was 2-fold: to biomechanically compare 1) initial stability, and 2) the effect of bone density on the stability of intramedullary nail and blade plate fixation in tibiotalocalcaneal arthrodesis.

Biomechanical stability of intramedullary nailed high proximal third tibial fractures with cement augmented proximal screws.

Objective: Intramedullary nailing of nonarticular proximal tibia fractures can be affected by bone density resulting in loss of stability, fixation, and malalignment in osteopenic bone. This study was designed to quantify the biomechanical effects of augmenting proximal screws with cement in intramedullary nailing of high proximal third tibial fractures.

Design: In vitro biomechanical study using anatomic specimens.

Biomechanical assessment of stability in the metastatic spine following percutaneous vertebroplasty: effects of cement distribution patterns and volume.

Percutaneous vertebroplasty is a minimally invasive, radiologically guided procedure whereby bone cement is injected into structurally weakened vertebrae to provide added biomechanical stability. In addition to treating osteoporotic vertebral fractures, this technique is also used to relieve pain by stabilizing metastatically compromised vertebrae that are at risk of pathologic burst fracture. Optimal cement distribution patterns to improve biomechanical stability to metastatically involved vertebral bodies remain unknown.

Pressurization of the metastatic femur during prophylactic intramedullary nail fixation.

Background: Venting during prophylactic nailing of metastatic femoral lesions may decrease intramedullary pressures and the risk of fat and tumor embolization. This study aimed to quantify maximum intramedullary pressure levels and durations, and to examine tumor displacement during prophylactic reamed intramedullary nailing of vented and nonvented metastatically involved femora.

Methods: Proximal metastatic defects were simulated in six pairs of cadaveric femora and prophylactically treated using reamed intramedullary nailing with or without proximal and distal vents.

Metastatic burst fracture risk prediction using biomechanically based equations.

Clinical guidelines are a useful adjunct to select patients with spinal metastases for prophylactic intervention. The objective of this study is to determine the ability of biomechanically based models to accurately predict metastatic burst fracture risk. Ninety-two vertebrae with osteolytic spinal metastases were examined retrospectively.

An anthropometric study of the distal ulna: implications for implant design.

Arthroplasty of the distal ulna is frequently used for distal radioulnar joint disorders; however, prosthetic failures are common. An implant replicating the ulna may be advantageous from the viewpoint of joint kinematics, wear, and fixation. The geometry of 40 distal ulnas was quantified by computed tomography scanning and radiography.