[Comparative study of femoral head replacement and internal fixation in the treatment of unstable intertrochanteric fractures in the elderly].

OBJECTIVE: To compare the clinical efficacy of femoral head replacement and internal fixation in the treatment of unstable intertrochanteric fractures in the elderly. METHODS: Retrospective analysis of 70 cases of unstable intertrochanteric fractures treated from January 2016 to January 2019 and meeting the inclusion and exclusion criteria, 39 cases were fixed with closed reduction and new proximal femoral intramedullary nail(InterTAN), and 31 cases were treated with open trochanter reconstruction and artificial femoral head replacement. The operation time, intraoperative bleeding, hospital stay, weight bearing time, postoperative complication rate and hip function recovery (Harris score) were compared between two groups. RESULTS: All cases were followed up for 12 to 24 months. There were no significant differences in intraoperative bleeding and hospital stay between the two groups (P>0.05). The operation time in replacement group was longer than that in internal fixation group (P< 0.05). The postoperative weight-bearing time in replacement group was significantly earlier than that in internal fixation group (P<0.05). In the replacement group, there were 1 case of pulmonary infection, 1 case of deep venous thrombosis and 1 case of periprosthetic fracture;in the internal fixation group, there were 4 cases of pulmonary infection, 3 cases of internal fixation failure, 3 cases of cerebral infarction and 2 cases of urinary infection;there was significant difference between two groups (P< 0.05). The Harris score in replacement group was higher than that in internal fixation group one month after operation (P< 0.05), but there was no significant difference between two groups at 12 months after operation(P>0.05). CONCLUSION: InterTAN and femoral head replacement can treat unstable intertrochanteric fractures in the elderly, but femoral head replacement can move down early, improve the quality of life at the end of life, reduce postoperative complications and facilitate the treatment of coexisting diseases in internal medicine.

Long-term sky islands generate highly divergent lineages of a narrowly distributed stream salamander (Pachyhynobius shangchengensis) in mid-latitude mountains of East Asia.

BACKGROUND: Climate oscillation may have a profound effect on species distributions, gene flow patterns and population demography. In response to environmental change, those species restricted to montane habitats experienced expansions and contractions along elevation gradients, which can drive differentiation among sky islands. RESULTS: The Shangcheng stout salamander (Pachyhynobius shangchengensis) is a cool stream amphibian restricted to high-elevation areas in the Dabie Mountains, East China. In the present study, we used mtDNA genes (Cyt b and ND2) of 193 individuals and 12 nuclear microsatellite loci genotyped on 370 individuals, representing 6 populations (JTX, KHJ, MW, TTZ, BYM and KJY) across the taxon's distribution area, to investigate their genetic variation and evolutionary history of P. shangchengensis. Most populations showed unusually high levels of genetic diversity. Phylogenetic analyses revealed five monophyletic clades with divergence times ranging from 3.96 to 1.4 Mya. Accordingly, significant genetic differentiation was present between these populations. Bayesian skyline plot analyses provided that all populations underwent long-term population expansions since the last inter-glacial (0.13 Mya ~ 0.12 Mya). Msvar analyses found recent signals of population decline for two northern populations (JTX and KHJ) reflecting a strong bottleneck (approximately 15-fold decrease) during the mid-Holocene (about 6000 years ago). Ecological niche modelling has shown a discontinuity in suitable habitats for P. shangchengensis under different historical climatic conditions. CONCLUSIONS: Our results suggest that the niche conservatism of P. shangchengensis and sky island effects may have led to long-term isolation between populations. In sky island refuges, the mid-latitude Dabie Mountains have provided a long-term stable environment for P. shangchengensis, which has led to the accumulation of genetic diversity and has promoted genetic divergence.