Unstable and displaced proximal humerus fractures remain a treatment challenge. The use of locked plates has improved construct stability, but complication rates remain high. Biomechanical studies have emphasized the importance of anchoring screws in the subchondral bone of the humeral head to improve implant stability. However, the spherical shape of the proximal humerus and the limited tactil...

STUDY DESIGN A prospective self-controlled study. OBJECTIVE The aim of the present study was to compare the application and clinical outcomes of transposterior arch lateral mass screw and lateral mass screw fixation of the atlas in the treatment of atlantoaxial instability. SUMMARY OF BACKGROUND DATA Atlas posterior screw fixation techniques comprise transposterior arch lateral mass screw f...

In cases of chronic irreducible and recurrent unstable atlantoaxial rotatory fixation (AARF), closed reduction and its maintenance are often unsuccessful, requiring surgical treatment. The purpose of the present report is to describe a rare case of pediatric AARF that required multiple treatments. A 6-year-old boy was diagnosed as having type 2 AARF. After conservative treatment, the patient wa...

Progress Using mathematical models, we are investigating the influence of plate fixation on the internal stresses in long bones subjected to all known in vivo loading modes . The variables we are studying include : plate geometry, plate/bone fixity, and screw tightness. The mathematical models are based upon the finite element technique . The models will be subjected to all physiological loadin...

1. Most of Schatzker Type II and Type III tibial plateau fractures are seen in osteoporotic bones in older age and are comminuted most of the times which have been excluded from your study. 2. The diameter of the solid inner piston is 10 mm may not be sufficient to elevate comminuted fragments. 3. Why not use bone graft to support elevated bone fragments because we are not sure if the screw can...

Secure fixation of bone-patellar tendon-bone grafts is essential to allow early joint mobilization after anterior cruciate ligament (ACL) reconstruction surgery. This study was designed to evaluate four fixation methods of patellar tendon-bone grafts in cadaveric knees. Fifty-one fresh cadaveric patellar tendon-bone specimens were anchored in tibial or femoral metaphyseal bone tunnels. Group I ...

BACKGROUND Medial open wedge high tibial osteotomy is a well-established procedure for the treatment of unicompartmental osteoarthritis and symptomatic varus malalignment. We hypothesized that different fixation devices generate different fixation stability profiles for the various wedge sizes in a finite element (FE) analysis. METHODS Four types of fixation were compared: 1) first and 2) sec...

PURPOSE To evaluate the influence of different implant numbers and connection types on the biomechanical behavior of mandibular full-arch implant-supported rehabilitation. MATERIALS AND METHODS Computed tomography-based finite element models comprising a totally edentulous mandible and 3.8 × 13-mmdiameter implants, abutments, abutment screws, bar retaining screw, and bar were constructed. Dif...

BACKGROUND AND PURPOSE Established methods of assessing bone mineral density are associated with additional radiation exposure to the patient. In this study, we aimed to validate a method of assessing bone mineral density in routine multidetector row CT of the lumbar spine. MATERIALS AND METHODS In 38 patients, bone mineral density was assessed in quantitative CT as a standard of reference an...