Bicompartmental, medial and patellofemoral knee replacement might be able to maintain unloaded knee kinematics.

INTRODUCTION: Unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) are standard procedures for treating knee joint arthritis. Neither UKA nor TKA seems to be optimally suited for patients with bicompartmental osteoarthritis that affects only the medial and patellofemoral compartments. A bicompartmental knee arthroplasty (BKA) was designed for this patient group. This study aimed to compare the effectiveness of a BKA and TKA in restoring the kinematics of the knee joint. MATERIALS AND METHODS: In this in vitro study, three types of knee arthroplasties (BKA, posterior cruciate ligament-retaining, and posterior cruciate ligament-resecting TKA) were biomechanically tested in six freshly frozen human cadaveric specimens. Complete three-dimensional kinematics was analyzed for each knee arthroplasty during both passive and loaded conditions in a validated knee kinematics rig. Infrared motion capture cameras and retroreflective markers were used for recording data. RESULTS: No significant differences could be found between the three types of arthroplasties. However, similar kinematic changes between BKA and a native knee joint were documented under passive conditions. However, in a weight-bearing mode, a significant decrease in femoral rotation during the range of motion was found in arthroplasties compared to the native knee, probably caused by contraction of the quadriceps femoris muscle, which leads to a decrease in the anterior translation of the tibia. CONCLUSIONS: Kinematics similar to that of the natural knee can be achieved by BKA under passive conditions. However, no functional advantage of BKA over TKA was detected, which suggests that natural knee kinematics cannot be fully imitated by an arthroplasty yet. Further prospective studies are required to determine the anatomic and design factors that might affect the physiologic kinematics.

Neurohormonal Regulation of Appetite and its Relationship with Stress: A Mini Literature Review.

Stress has long been known to affect eating behaviors in humans. Stress-induced hyperphagia is considered a potential cause for the development of obesity. Given the high prevalence of obesity and its association with other cardiovascular and metabolic disorders, the subject of stress-induced eating has become even more important. We reviewed data from past studies to further elucidate the relationship between stress, appetite regulation and eating patterns in humans. Even though it is difficult to say with certainty that a person exposed to stress will undereat or overeat, but certain assumptions can be made. Generally, acute stress results in decreased eating whereas chronic stress results in increased eating. Glucocorticoids, the effector molecules of the stress response, increase the tendency to consume high-calorie, palatable foods. Further studies that can link the biological markers of stress-response with the hormones and neurotransmitters of appetite regulation can broaden our understanding of the subject. These studies can provide a groundwork for the development of effective anti-obesity strategies.

Optic Disc Pit Maculopathy Triggered by Childbirth.

We describe a case of a healthy lady with a known optic disc pit who developed serous maculopathy a few hours after childbirth. We believe this is the first published description of a trigger factor responsible for serous macular detachment in eyes known to have a disc pit. She was successfully treated by means of pars plana vitrectomy and gas injection, resulting in slight visual improvement.

Fourier-domain optical coherence tomography imaging of gas tamponade following macular hole surgery.

In this prospective study, the authors report fourier-domain optical coherence tomography (FD-OCT) imaging of gas-inner retinal tamponade following surgery for full-thickness macular hole and evaluate postoperative posturing based on FD-OCT findings. Patients underwent FD-OCT 1 day after pars plana vitrectomy, internal limiting membrane peel, and gas injection. Three-dimensional FD-OCT and high-resolution line scans demonstrated gas-inner retinal tamponade across the macula with the apex of tamponade located at the fovea. Inner and outer retina landmarks could be accurately identified along the curvature of the eye using FD-OCT in x-, y-, and z-planes. No patients required face-down positioning postoperatively based on FD-OCT findings. Satisfactory gas-inner retinal tamponade with 75% fill of any gas agent in the upright position was observed. Full-thickness macular hole closure was successful in 90% at 1 day, 2 weeks, and 12 weeks postoperatively. These FD-OCT findings may support decisions to not require face-down positioning postoperatively.

Fourier-domain optical coherence tomography imaging of gas tamponade following macular hole surgery.

In this prospective study, the authors report fourier-domain optical coherence tomography (FD-OCT) imaging of gas-inner retinal tamponade following surgery for full-thickness macular hole and evaluate postoperative posturing based on FD-OCT findings. Patients underwent FD-OCT 1 day after pars plana vitrectomy, internal limiting membrane peel, and gas injection. Three-dimensional FD-OCT and high-resolution line scans demonstrated gas-inner retinal tamponade across the macula with the apex of tamponade located at the fovea. Inner and outer retina landmarks could be accurately identified along the curvature of the eye using FD-OCT in x-, y-, and z-planes. No patients required face-down positioning postoperatively based on FD-OCT findings. Satisfactory gas-inner retinal tamponade with 75% fill of any gas agent in the upright position was observed. Full-thickness macular hole closure was successful in 90% at 1 day, 2 weeks, and 12 weeks postoperatively. These FD-OCT findings may support decisions to not require face-down positioning postoperatively.

Evidence and mechanisms of retrogenesis in Alzheimer's and other dementias: management and treatment import.

Retrogenesis is the process by which degenerative mechanisms reverse the order of acquisition in normal development. Alzheimer's disease (AD) and related conditions in the senium have long been noted to resemble "a return to childhood" Previously, we noted that the functional stages of AD precisely and remarkably recapitulated the acquisition of the same functional landmarks in normal human development. Subsequent work indicated that this developmental recapitulation also applied to the cognitive and related symptoms in AD. Remarkably, further investigations revealed that the same neurologic "infantile" reflexes, which mark the emergence from infancy in normal development, are equally robust indicators of corresponding stages in AD. Neuropathologic and biomolecular mechanisms for these retrogenic processes are now evident. For example, the pattern of myelin loss in AD appears to mirror the pattern of myelin acquisition in normal development. Also, recent findings indicate that mitogenic factors become reactivated in AD, and, consequently, the most actively "growing" brain regions are the most vulnerable. Because of this robust retrogenic process, the stages of AD can be translated into corresponding developmental ages (DAs). These DAs can account for the overall management and care needs of AD patients. A science of AD management can be formulated on the basis of the DA of the Alzheimer's patient, taking into consideration differences of AD from normal development as well as homologies.