The objective of this study was to compare the effectiveness of a newly developed DJO Global cervical collar with the previously studied Össur Americas Miami J collar in restricting cervical spine movement and reducing tissue interface pressure. 3D kinematic data were obtained for twelve healthy participants volunteers (6 female, 6 male) using a 10 camera infrared motion capture system (Motion Analysis Corp.). Cervical range of motion (CROM) in each plane was calculated as the angle between the head and thorax rigid-body axes. CROM was calculated using custom-written Matlab (MathWorks, Natick, MA) scripts. Tissue interface pressure (TIP) was measured between the head and the collar with three flexible pressure sensor pads over the anterior mandibles and occiput. The distribution of interface pressures was obtained in both the seated and supine positions. Both collars significantly restricted range of motion in all movement directions (p < 0.001) compared to no collar. There were no statistically significant differences in restrictiveness nor tissue interface pressures between the collars. Both collars exhibited similar CROM restriction in all planes and similar interface pressures in both positions. The newly developed DJO collar properly functioned as it markedly restricted spinal movement and produced low contact pressures. The Miami J collar has long been scientifically recognized as an effective collar; however, our data shows that the latest DJO collar was able to exhibit comparable contact pressures and decreases in cervical motion. As manufacturers produce improved collar designs, continued scientific testing should be executed in search of a collar capable of enhanced CROM restriction and the diminution of TIP.

Obesity is a growing issue in the Western world, as well as other international countries. This is leading to increases in complications associated with obesity. One such complication is osteoarthritis (OA) of load bearing joints that requires surgical treatment by total knee arthroplasty (TKA). Obesity is also associated with an increase in surgical complications that may lead to poor TKA outcomes. Additionally, the female gender is also known to be associated with increased rates of severe, clinical OA. This study was designed to determine the comparative efficacy of two knee implants in the obese female population through retrospective chart review and data analysis. The implants differ in their level of constraint, with the total stabilizing (TS) being more constrained than the posterior stabilizing (PS). We hypothesized that the TS implants would be associated with improved functional outcomes in the obese female population. The TS implant was observed to be associated with earlier improvement of both passive and active range of motion. This implant also showed greater improvement from pre-operative condition in stability, rejecting our null hypothesis and supporting our hypothesis.

Olecranon fractures account for approximately 10% of upper extremity fractures and 95% of them require surgical fixation. Most of the clinical, retrospective and biomechanical studies have supported plate fixation over other surgical fixation techniques since plates have demonstrated low incidence of reoperation, high fixation stability and resumption of activities of daily living (ADL) earlier. Thus far, biomechanical studies have been helpful in evaluating and comparing different plate fixation constructs based on fracture stability. However, they have not provided information that can be used to design rehabilitation protocols such as information that relates load at the hand with tendon tension or load at the interface between the plate and the bone. The set-ups used in biomechanical studies have included simple mechanical testing machines that either measured construct stiffness by cyclic loading the specimens or construct strength by performing ramp load until failure. Some biomechanical studies attempted to simulate tendon tension but the in-vivo tension applied to the tendon remains unknown. In this study, a novel procedure to test the olecranon fracture fixation using modern olecranon plates was developed to improve the biomechanical understanding of failures and to help determine the weights that can be safely lifted and the range of motion (ROM) that should be performed during rehabilitation procedures.

Design objectives were defined based on surgeon's feedback and analysis of unmet needs in the area of biomechanical testing. Four pilot cadaveric specimens were prepared to run on an upper extremity feedback controller and the set-up was validated based on the design objectives. Cadaveric specimen preparation included a series of steps such as dissection, suturing and potting that were standardized and improved iteratively after pilot testing. Additionally, a fracture and plating protocol was developed and fixture lengths were standardized based on anthropometric data. Results from the early pilot studies indicated shortcomings in the design, which was then iteratively refined for the subsequent studies. The final pilot study demonstrated that all of the design objectives were met. This system is planned for use in future studies that will assess olecranon fracture fixation and that will investigate the safety of rehabilitation protocols.