[THE CONCEPT OF SURGICAL TREATMENT OF INTRA-ARTICULAR FRACTURES OF THE DISTAL FEMUR: LCP PLATE OR RETROGRADE INTRAMEDULLARY NAIL]

This study compares the results of treatment of two groups of patients who underwent osteosynthesis of intra-articular fractures of the distal femur using the LCP plate and an intramedullary retrograde nail. 89 patients with fractures of the distal femur were divided into 2 groups: group I (n=43) - patients who underwent osteosynthesis of intra-articular fractures of the distal femur using an LCP bone plate and group II (n=46) - using an intramedullary retrograde pin. The comparison was carried out according to the duration of the surgical operation, the amount of time elapsed from the moment of injury to surgery, and blood loss. In group II with intramedullary osteosynthesis, the time of surgical treatment was statistically significantly less than in the group of bone osteosynthesis - 45 minutes and 65 minutes, respectively. Reducing the duration of the operation leads to better functional treatment results. The reduction of the operation time when installing a retrograde intramedullary pin is due to the easier installation technique of this type of retainer and the use of minimally invasive approaches.In patients after surgical interventions, complications were detected in both groups. The nature and frequency of complications in the groups are approximately the same. Infectious complications in the early postoperative period occurred in 4 (9.3%) patients in the group of bone osteosynthesis and 4 (8.6%) - in the group of intramedullary osteosynthesis. In all cases, superficial infection of the postoperative wound within the skin and subcutaneous fat was noted. In the group of bone osteosynthesis, 2 (4.6%) patients in the long-term period were diagnosed with a deep infection of the femoral osteosynthesis area, which required repeated surgical intervention. No cases of deep infection were recorded in the intramedullary osteosynthesis group.In the group of patients who underwent bone osteosynthesis, osteoarthritis of the knee joint of the I degree was detected in 35 (81.4%) patients, in 8 (18.6%) - after 3.5 years of follow-up, the formation of osteoarthritis of the II degree was noted. In the group of patients using intramedullary osteosynthesis, grade I arthrosis was detected in 36 (78.2%) patients, and grade II - in 10 (21.8%) patients. 3,5 years after the operation, there was no need for knee replacement in any patient.The retrograde intramedullary osteosynthesis technique of femoral condyle fractures in the long-term period revealed the best functional indicators.

Impaired hippocampal-cortical coupling but preserved local synchrony during sleep in APP/PS1 mice modeling Alzheimer's disease

Sleep, in addition to its brain restorative processes, plays an important role in memory transfer from its temporary store in the hippocampus to the more permanent storage in the neocortex. Alzheimer’s disease (AD) affects memory and sleep. The aim of this study was to explore disturbances in global and local synchrony patterns between brain regions in the APP/PS1 mouse model of the AD during natural sleep. We used 8 male APPswe/PS1dE9 mice and 6 wild-type littermates, aged 5–6 months, with multiple electrode bundles implanted into cortical regions, thalamus and hippocampus. We measured video-EEG in freely moving animals and analyzed synchrony during NREM vs REM sleep. Global synchrony between medial frontal cortex and hippocampus measured with magnitude-squared coherence was slightly decreased in delta range during NREM stage of sleep in APP/PS1 mice. In contrast, local hippocampal synchrony measured with cross-frequency coupling remained intact. Ripple structure or frequency did not differ between the genotypes. However, the coupling of the spindle-band power peak in the medial prefrontal cortex to hippocampal ripples was significantly decreased compared to wild-type animals. The delicate timing of hippocampal ripples, frontal delta, and corticothalamic spindle oscillations may be the first sign of impaired memory in amyloid plaque-forming transgenic mice.