Biomedical subjects

R D Goldner

Publications and source records attributed to R D Goldner.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Stiffness of simulated radial neck fractures fixed with 4 different devices.

We performed a structural investigation of several fixation devices for radial head and neck fixation. Fourteen pairs of fresh-frozen human elbows were used to simulate unstable radial neck fractures fixed with each of the following plates: 2.0-mm T-plate, 2.0-mm blade plate, 2.7-mm T-plate, and 2.7-mm T-plate modified with a fixed-angle blade. The plate constructs were axially loaded in compression with a materials testing machine, and stiffness was calculated from a load-deformation curve. Through use of paired comparisons, the average stiffness of the modified 2.7-mm plate was found to be significantly greater than that of either 2.0-mm plate, whereas a trend was observed for increased stiffness of the modified 2.7-mm T-plate in comparison with the standard 2.7-mm T-plate. The results indicate that two important variables affecting construct stiffness are plate thickness and incorporation of a fixed-angle blade. Given these findings, the addition of a fixed blade to the 2.7-mm plate may improve the stability of fixation of comminuted radial neck fractures.

Adult↗

PubMedDate not supplied

Medial or lateral dislocation (snapping) of a portion of the distal triceps: a biomechanical, anatomic explanation.

Medial and lateral snapping (dislocation) of the distal triceps over the epicondyle during elbow flexion has been reported but is frequently misdiagnosed and is not well understood. In this study a mathematical model was designed to simulate the effect that bony abnormalities at the distal humerus and soft tissue variations of the distal triceps have on the line of pull of the triceps. The predictions were then tested on prefabricated and fabricated plastic elbow models, as well as 8 cadaveric elbows. When the bony alignment was altered, varus angulation had the greatest effect: 30 degrees varus malalignment of the distal humerus displaced the centroid of the triceps vector medially by approximately 2.0 cm. Valgus malalignment had a lesser effect: 30 degrees valgus displaced it laterally by 1.5 cm. Negligible effects on the triceps line of pull were seen with internal or external malrotation and with flexion or extension malalignment. Of the soft tissue alterations, displacement of the triceps insertion had a greater effect than movement of the triceps origin. The triceps vector was displaced by approximately 70% of the amount of translation of the triceps insertion. The relationship between the triceps line of pull and the bony alignment is represented by the triceps (T) angle. Our use of the T angle to understand snapping triceps is analogous to the use of the quadriceps (Q) angle for patellar subluxation/dislocation. Treatment should aim to restore normal triceps biomechanics with soft tissue or bony procedures.

Arm↗

PubMedDate not supplied

The "blind side" of the medial meniscus.

The major posterior insertion of the medial meniscus is not into the tibial plateau proper but into a rather deep recess behind the intercondylar eminence. The shape of the meniscus in relation to the curve of the meniscotome and its angle of approach, and also the surgeon's inability to see posteriorly from an anterior incision make posterior capsular incision desirable in many cases. A posteromedial incision, added to the normal anteromedial one in 40 of 215 medial meniscectomies, did not increase perioperative morbidity.

Humans↗

PubMedDate not supplied

Indications for replantation in the adult upper extremity.

Physicians involved in the evaluation and initial treatment of patients with severe hand injuries should be familiar with the indicators for, the contraindications to, and expectations following replantation, including preoperative preservation of the amputated part. This article covers these topics and discusses experiences with various types of replantations.

Amputation, Traumatic↗