[Comparison of proximal femoral nail anti-rotation operation in traction bed supine position and non-traction bed lateral position in treatment of intertrochanteric fracture of femur].

OBJECTIVE: To compare the effectiveness of proximal femoral nail anti-rotation (PFNA) in the treatment of intertrochanteric fracture of femur in traction bed supine position and non-traction bed lateral position. METHODS: A retrospective analysis of 102 elderly patients with intertrochanteric fracture of femur who met the selection criteria between January 2013 and April 2018 was made. According to the different operative positions, the patients were divided into two groups: group A (50 cases, PFNA internal fixation in traction bed supine position) and group B (52 cases, PFNA internal fixation in non-traction bed lateral position). There was no significant difference in age, gender, fracture side, cause of injury, AO classification, complications, and time from injury to operation between the two groups ( P>0.05). The preoperative preparation time, incision length, operation time, intraoperative blood loss, intraoperative X-ray fluoroscopy times, fracture healing time, and complications were recorded and compared between the two groups, and the effectiveness was evaluated by Harris hip score at 1 year after operation. RESULTS: There was no significant difference in incision length between groups A and B ( t=1.116, P=0.268). In addition, the preoperative preparation time, operation time, intraoperative blood loss, and intraoperative X-ray fluoroscopy times in group A were significantly greater than those in group B ( P<0.05). Both groups were followed up 12-14 months, with an average of 13 months. There were 3 postoperative complications in group A and group B respectively. In group A, there were 2 cases of hip joint pain and 1 case of local fat liquefaction (healed after dressing change); in group B, there were 2 cases of hip joint pain and 1 case of deep vein thrombosis in lower extremity; there was no significant difference in the incidence of postoperative complications between the two groups ( P=0.642). The patients of the two groups had a good result of fracture reduction and the internal fixation quality, and there was no main nail loosening, screw fracture, spiral blade cutting, withdrawal, and the nail breakage occurred, and no nonunion of bone, coxa vara, and other complications occurred. X-ray showed that the fracture healed in both groups, and there was no significant difference in fracture healing time between the two groups ( t=1.515, P=0.133). There was no significant difference in Harris hip score between the two groups at 1 year after operation ( t=0.778, P=0.438). CONCLUSION: Compared with the traction bed supine position, PFNA internal fixation for intertrochanteric fracture of femur in the non-traction bed lateral position has the advantages of short preparation time, short operation time, less intraoperative blood loss, less X-ray fluoroscopy times, and satisfactory postoperative recovery effect.

A novel ASXL1-OGT axis plays roles in H3K4 methylation and tumor suppression in myeloid malignancies.

ASXL1 plays key roles in epigenetic regulation of gene expression through methylation of histone H3K27, and disruption of ASXL1 drives myeloid malignancies, at least in part, via derepression of posterior HOXA loci. However, little is known about the identity of proteins that interact with ASXL1 and about the functions of ASXL1 in modulation of the active histone mark, such as H3K4 methylation. In this study, we demonstrate that ASXL1 is a part of a protein complex containing HCFC1 and OGT; OGT directly stabilizes ASXL1 by O-GlcNAcylation. Disruption of this novel axis inhibited myeloid differentiation and H3K4 methylation as well as H2B glycosylation and impaired transcription of genes involved in myeloid differentiation, splicing, and ribosomal functions; this has implications for myelodysplastic syndrome (MDS) pathogenesis, as each of these processes are perturbed in the disease. This axis is responsible for tumor suppression in the myeloid compartment, as reactivation of OGT induced myeloid differentiation and reduced leukemogenecity both in vivo and in vitro. Our data also suggest that MLL5, a known HCFC1/OGT-interacting protein, is responsible for gene activation by the ASXL1-OGT axis. These data shed light on the novel roles of the ASXL1-OGT axis in H3K4 methylation and activation of transcription.

[Efficacy comparison of different methods to treat femoral intertrochanteric fracture in aged patients].

Objective: To compare the efficacy of proximal femoral nail anti-rotation (PFNA), locking compression plate (LCP), and artificial femoral head replacement for femoral intertrochanteric fracture in aged patients so as to provide reference for clinical treatment. Methods: A retrospective analysis was made on the clinical data of 150 aged patients with femoral intertrochanteric fracture treated between September 2009 and March 2016. PFNA was used in 51 cases (group A), LCP in 53 cases (group B), and artificial femoral head replacement in 46 cases (group C). There was no significant difference in sex, age, side, cause of injury, injury to operation time, type of fracture, and combined medical diseases between groups ( P>0.05). The incision length, operation time, intraoperative blood loss, time for full weight bearing, hip Harris score, and complications were recorded and compared between groups. Results: The patients were followed up 12-23 months (mean, 18.6 months) in group A, 12-25 months (mean, 19.0 months) in group B, and 12-24 months (mean, 18.9 months) in group C. The incision length, operation time, and intraoperative blood loss of group A were significantly less than those of groups B and C ( P<0.05); the operation time of group C was significantly shorter than that of group B ( P<0.05), but there was no significant difference in incision length and intraoperative blood loss ( P>0.05). The time for full weight bearing was significantly shorter in group C than groups A and B, and in group A than group B ( P<0.05). Postoperative complications occurred in 11 patients of group A (21.6%), 14 patients of group B (26.4%), and 2 patients of group C (4.3%), showing significant difference between group C and group A or group B ( P<0.05), but no significant difference was found between groups A and B ( P>0.05). Hip Harris score at 12 months after operation had no significant difference between groups ( P>0.05). Conclusion: PFNA, LCP, and artificial femoral head replacement are all effective methods to treat femoral intertrochanteric fracture in aged patients. PFNA has the advantages of small incision, short operation time, less bleeding and simple procedure, and artificial femoral head replacement has the advantages of early time for full weight bearing, less bed rest time, and less complications. For these patients, PFNA and artificial femoral head replacement are appropriate.

N-terminal telopeptides of type I collagen and bone mineral density for early diagnosis of nonunion: An experimental study in rabbits.

BACKGROUND: The diagnosis and treatment of bone nonunion have been studied extensively. Diagnosis and treatment of nonunion are mainly performed based on the interpretation of clinico-radiographic findings, which depend on the clinician's experience and the degree of bone callus formation during the fracture-healing process. However, resolution may be compromised when the bone mineral content is <25%. A feasible method of monitoring bone-healing is therefore needed. We monitored a rabbit model of bone nonunion by regular radiographic examinations, QCT detection, and biomarker concentrations. MATERIALS AND METHODS: Twenty purebred New Zealand rabbits (10 male and 10 female, 5-6 months of age, 2.5-3.0 kg) were divided into bone defect Group (I) that 10 left radius bones underwent resection of 1.5 cm of mid-radius bone and bone fracture Group (II) that another 10 left radius bones underwent only mid-radius fracture. Quantitative computed tomography detection of bone mineral density (BMD) and serum markers of bone formation (osteocalcin [OC], bone-specific alkaline phosphatase) and bone resorption (C- and N-terminal telopeptides of type I collagen (NTX) and tartrate-resistant acid phosphatase 5b) were assayed. There are twenty rabbits (10 male and 10 females). The age was 5-6 months weighing 2.5-3.0 kg). The defect was created in middle 1/3 radius in 10 rabbits and fracture was created in middle 1/3 radius of 10 rabbits. RESULTS: BMD and NTX concentrations were significantly lower at 5 weeks postoperatively compared to the preoperative values and were significantly different between the two groups. OC showed no significant difference before and after surgery. CONCLUSIONS: BMD and NTX concentrations may be useful for early detection of bone nonunion in rabbits.

Serum N-terminal telopeptide of type I collagen as an early marker of fracture nonunion in rabbits.

The aim of the present study was to establish an experimental animal model of fracture nonunion, and to investigate the changes in serum biomarker concentrations in fracture nonunion. A total of 20 purebred New Zealand rabbits were divided into two group: A bone defect group and a bone fracture group. In the bone defect group, a 15-mm section of bone (including the periosteum) was removed from the mid-radius, and the medullary cavities were closed with bone wax. In the bone fracture group, the mid-radius was fractured. X-rays were taken and blood samples were collected preoperatively and at 2, 3, 4, 5, 6, 7, 8, 10 and 12 weeks after the surgical procedure. The serum concentrations of osteocalcin (OC) and bone-specific alkaline phosphatase (BSAP) served as markers of bone formation, and those of C-terminal telopeptide of type I collagen (CTX), N-terminal telopeptide of type I collagen (NTX) and tartrate-resistant acid phosphatase 5b (TRACP 5b) served as markers of bone resorption. The concentration levels of the markers were measured using a biotin double-antibody sandwich enzyme-linked immunosorbent assay. In the bone defect group, bone callus was observed on X-ray at 2 weeks in three rabbits and the bone calluses stabilized at 5 weeks; however, none of the bones had healed at 8 weeks. In the bone fracture group, the fracture line was distorted at 2 weeks and bone calluses formed at 6-8 weeks. In the bone defect group, the serum BSAP and TRACP 5b concentrations increased following the surgical procedure, peaked at 4 weeks, began to decrease at 5 weeks and stabilized after 6 weeks. The serum OC concentrations did not change significantly following the surgical procedure. The serum CTX concentrations fluctuated during the first 4 weeks, peaked at 5 weeks, then decreased and stabilized after 6 weeks. The serum NTX concentrations fluctuated during the first 4 weeks, were significantly lower at 5 weeks compared with the other time points and stabilized after 6 weeks. These results suggested that a bone nonunion model can be established in New Zealand rabbits by resecting a 15-mm section of bone from the mid-radius prior to bone wax blocking. Measurement of the serum BSAP, CTX, NTX, and TRACP 5b concentrations may be useful for the early detection of bone nonunion. The serum NTX concentrations changed significantly in rabbits with bone nonunion. Further studies are required in order to determine the feasibility of using serum NTX concentrations for the early diagnosis of bone nonunion.