Effect of Active and Passive Function of the Posterosuperior Rotator Cuff on Compensatory Muscle Loads in the Shoulder.

Background: Irreparable posterosuperior rotator cuff (PSRC) tears have been shown to result in shoulder pain and loss of function.

Purpose/hypothesis: The purpose of this study was to determine the effect of the loss of active or passive function of the PSRC on compensatory muscle loads in the deltoid and the remaining rotator cuff. It was hypothesized that both deactivation and resection of the PSRC would result in load increases in the remaining muscles and that resection of the PSRC would result in even higher required compensatory forces than would mere deactivation.

Outcomes of COVID-19 Critically Ill Extremely Elderly Patients: Analysis of a Large, National, Observational Cohort.

Background: During the COVID-19 pandemic, resource allocation became a major problem in globally overwhelmed ICUs. The main goal of this study was to describe the clinical characteristics of the very elderly patients (aged ≥ 80 years) with COVID-19 admitted in Romanian ICUs. The study objectives were to evaluate and determine the factors associated with ICU mortality.

Development and Multisite Assessment of a Novel Shoulder Motion Joint Simulator.

Multiple biomechanical shoulder simulators have been described in the literature, with a trend toward increasing complexity to better simulate clinical scenarios. Our objective was to develop an advanced, novel shoulder joint simulator and compare outcomes at two separate institutions, for a typical shoulder joint motion simulation. Identical shoulder simulators were developed & deployed at both institutions.

Scapular motion in the presence of rotator cuff tears: a systematic review.

Background: Rotator cuff tears (RCTs) remain a significant source of pain and disability in the shoulder. Although much work has been done in the study of the effects of rotator cuff tears on glenohumeral joint motion, much less has been done in understanding the effect of rotator cuff tearing on scapular motion or activation. It remains unknown whether scapular dyskinesis is causative or adaptive.

Device-length changes and implant function following surgical implantation of the KineSpring in cadaver knees.

Introduction: The KineSpring implant system has been shown to provide load reductions at the medial compartment of the knee, and has demonstrated clinical success in reducing pain and increasing function in patients with medial knee osteoarthritis. These results depend on the ability of the KineSpring to rotate, lengthen, and shorten to accommodate knee motions, and in response to knee position and loading.

Purpose: The present study was undertaken to determine length changes of the implanted KineSpring in response to a range of knee positions, external knee loads, and placements by different orthopedic surgeons.

The KineSpring(®) Knee Implant System: an implantable joint-unloading prosthesis for treatment of medial knee osteoarthritis.

Symptomatic medial compartment knee osteoarthritis (OA) is the leading cause of musculoskeletal pain and disability in adults. Therapies intended to unload the medial knee compartment have yielded unsatisfactory results due to low patient compliance with conservative treatments and high complication rates with surgical options. There is no widely available joint-unloading treatment for medial knee OA that offers clinically important symptom alleviation, low complication risk, and high patient acceptance.

Unloading the osteoarthritic knee with a novel implant system.

Medial knee osteoarthritis (OA) is a common disorder often associated with pathologic joint loading. Insoles, braces, and high tibial osteotomy are OA treatments aimed at reducing medial joint loads, but their use and effectiveness are limited. The KineSpring System implant also intends to reduce knee loads in OA patients while overcoming those limitations.

Evaluation of the safety of a novel knee load-bypassing device in a sheep model.

Background: Unloading treatments for osteoarthritis of the knee, such as valgus braces, have been shown to reduce medial joint-loading and pain. The purpose of this preclinical study was to investigate the tissue response to an extracapsular implantable device (KineSpring System; Moximed, Hayward, California) that is designed to reduce loading across the medial compartment of the knee.

Methods: Eleven sheep were implanted with the KineSpring System, consisting of bases secured to the medial femoral and tibial cortices with bone screws and also consisting of a joint-spanning load-absorber composed of a piston and spring assembly inside a polymeric sheath.

In vitro wear assessment of the Charité Artificial Disc according to ASTM recommendations.

Study Design: Biomechanical laboratory research.

Objective: To evaluate the potential for Ultra High Molecular Weight Polyethylene (UHMWPE) wear debris from the Charité Artificial Disc.

Summary Of Background Data: Cases of osteolysis from artificial discs are extremely rare, but hip and knee studies demonstrate the osteolytic potential and clinical concern of UHMWPE wear debris.

Three-dimensional determination of femoral-tibial contact positions under in vivo conditions using fluoroscopy.

OBJECTIVE: A method has been developed to accurately measure three-dimensional (3-D) femoral-tibial contact positions of artificial knee implants in vivo from X-ray fluoroscopy images using interactive 3-D computer vision algorithms. DESIGN: A computerized graphical (CAD) model of an implant component is displayed as an overlay on the original X-ray image. An image matching algorithm matches the silhouette of the implant component against a library of images, in order to estimate the position and orientation (pose) of the component.