A unilateral external fixator combined with bone transport and tibio-talar fusion for the treatment of severe postoperative infection of peri-ankle fractures: retrospective analysis of 32 cases.

BACKGROUND: To investigate the clinical effects of a unilateral external fixator combined with bone transport and tibio-talar fusion in the treatment of severe postoperative infection of peri-ankle fractures. METHODS: The clinical data of 32 patients (22 men and 10 women) with severe postoperative infection of peri-ankle fractures were retrospectively analyzed. Patients' age ranged from 26 to 62 (mean, 42 ± 9.5) years old. The types of fractures were distal tibia fracture (25 cases), distal tibia and fibula fracture (5 cases), and talus fracture (2 cases). All patients underwent treatment with unilateral external fixation combined with bone transport and tibio-talar fusion. 6 patients with severe infection received two-stage treatment involving focal debridement and external fixation, osteotomy, and bone transport. The remaining 26 patients underwent debridement, external fixation, and osteotomy simultaneously. The length of bone transport, total fixation time of the external fixator, and postoperative complications were recorded for all patients. The efficacy of the treatment was assessed using the American Association of Foot and Ankle Society (AOFAS) ankle-hindfoot score. RESULTS: Patients were followed up for 16-36 months, with an average follow-up time of 24 months. The length of tibia bone transport ranged from 5 to 15 cm, with a mean length of 8.5 cm. The external fixator was applied for 12-24 months, with an average duration of 16 months. One patient suffered from refracture at tibio-talar fusion site, and one patient had external fixation pin-tract infection. No complications, such as recurrent infections (especially the MRSA infection), poor mineralization, refracture, iatrogenic nerve damage or fusion failure, were found in the remaining patients. The preoperative AOFAS ankle-hindfoot function score was 40.0 ± 3.8 (range, 30-52) points, and it increased to 75.0 ± 3.0 (range, 67-78) points at the last follow-up. CONCLUSION: A unilateral external fixator combined with bone transport and tibio-talar fusion is an effective method for treating severe postoperative infection of peri-ankle fractures. This approach is capable of reconstructing large bone defects that remain after clearing the infected lesion. Additionally, it provides stability to the ankle, enhances ankle-hindfoot function, and improves the patient's quality of life.

Biomechanical tests and finite element analyses of pelvic stability using bilateral single iliac screws with different channels in lumbo-iliac fixation.

Background: In lumbo-iliac fixation, the iliac screw can be placed in several locations and directions. There is no uniform standard for the placement of a single iliac screw. Biomechanical tests and finite element analyses were used to compare the effect of bilateral single iliac screws with three channels on pelvic stability to determine the best channel. Methods: Five embalmed adult cadaver pelvic specimens were selected. An unstable Tile C1 pelvic injury model was established. Lumbo-iliac fixation for the treatment of left sacral Denis II fracture includes the following: three channels of bilateral, single iliac screws (channel A from posterior superior iliac spine (PSIS) to anterior inferior iliac spine (AIIS), channel B from 1 cm medial and 1 cm caudal of PSIS to AIIS, and channel C from 2 cm below PSIS to AIIS). Biomechanical testing was performed for stiffness evaluations. A finite element model was established to study the stress distribution of the model and the maximum von Mises stress of internal fixation. Results: Biomechanical tests revealed that under vertical compression loading. The compressive stiffness fixed by channel B (246.15 ± 27.85 N/mm) was better than that fixed by channel A and channel C. Under torsional load, the torsional stiffness fixed by channel B (2.234 ± 0.223 N·m/°) was stronger than that fixed by channel A and channel C. However, there was no significant difference in terms of compressive and torsional stiffness between channel B and channel A (P > 0.05). Finite element analyses conformed that the maximum von Mises stress of the internal fixator fixed in channel B under the conditions of vertical, forwards bending, backwards extension, left bending, left rotating, and right bending (213.98 MPa, 338.96 MPa, 100.63 MPa, 297.06 MPa, 200.95 MPa and 284.75 MPa, respectively) was significantly lower than those fixed in channel A and channel C. Conclusions: The construct stiffness of the channel from 1 cm medial and 1 cm caudal of PSIS to AIIS is better than that of the other two channels. This channel has the advantages of good biomechanical stability, small maximum von Mises stress of internal fixation.

Incidence of Traumatic Sciatic Nerve Injury in Association with Acetabular Fracture: A Retrospective Observational Single-Center Study.

Purpose: Traumatic sciatic nerve injury is one of the most serious consequences of acetabular fracture. However, reports on this type of injury are rare. In this study, we investigated the demographics of acetabular fracture with traumatic sciatic nerve injury, the clinical characteristics of patients with these injuries, and potential risk factors. Patients and Methods: We retrospectively reviewed patients diagnosed to have acetabular fracture at our trauma center between January 2014 and June 2021. Data on patient demographics, characteristics of the acetabular fracture, whether or not sciatic nerve injury occurred, types of sciatic nerve injury, and risk factors were analyzed. Results: A total of 195 patients met the diagnostic criteria for acetabular fractures. The average Injury Severity Score was 25.9 and the average Abbreviated Injury Scale score was 12.4. Road traffic accidents and falls from height were the main causes. Chest injuries and lower extremity fractures were the most common associated injuries. Posterior wall fractures were the most common fracture type. After exclusion of spinal cord and iatrogenic sciatic nerve injuries, 18 patients with acetabular fractures had traumatic sciatic nerve injury. Four of the 19 sides with traumatic sciatic nerve injury involved the common peroneal nerve division and 15 involved both the common peroneal and tibial nerve divisions. Logistic regression analysis identified a higher AIS score, posterior column fracture, and posterior hip dislocation to be predictors of traumatic sciatic nerve injury. Conclusion: Acetabular fractures were mostly high-energy injuries. Posterior wall fractures were the most common acetabular fracture types. Most patients sustained injury to the sciatic nerve as well as injury to the common peroneal and tibial nerve divisions. A higher AIS score, posterior column fracture, and posterior hip dislocation were predictors of acetabular fracture combined with traumatic sciatic nerve injury.

Management and outcome of pelvic fracture associated with vaginal injuries: a retrospective study of 25 cases.

BACKGROUND: Pelvic ring fractures associated with vaginal injuries were rarely reported due to low incidence. The displaced segments of pelvic ring may increase the risk of vaginal injury. The aim of this retrospective study was to evaluate the correlation between pelvic fracture and vaginal injury. METHODS: We conducted a retrospective review of 25 patients with pelvic fractures associated with vaginal injury treated at our institution. The medical records of these patients were collected and 24 patients were followed-up for 10-36 months. RESULTS: All patients suffered anterior pelvic ring fracture. Young-Burgess fracture classification and compromised pubic symphysis were related to severity of vaginal injury. Gauze packing was done in 6 patients and 18 patients received surgical repair. Infection occurred in 6 patients, among them 4 were due to delayed diagnosis. Factors associated with pelvic outcome were age, urethral injury, and infection. Four patients suffered pain in sexual intercourse but no influence factor found correlated to sexual function. CONCLUSION: VS type pelvic fracture and compromised pubic symphysis were related to higher severity of vaginal injury. Disruption of anterior ring and an unstable pelvic ring caused by forces on coronary and axial plane may increase the risk of vaginal injury. TRIAL REGISTRATION: ChiCTR1900020540 . Registered 28 January 2019. Retrospectively registered. TRIAL REGISTRY: Chinese Clinical Trial Registry.

5-Azacytidine and trichostatin A enhance the osteogenic differentiation of bone marrow mesenchymal stem cells isolated from steroid-induced avascular necrosis of the femoral head in rabbit.

Bone marrow mesenchymal stem cells (BMSCs) play an important role in the process of bone repair. The present study investigated the effect of 5-azacytidine (AZA) and trichostatin A (TSA) on BMSC behaviors in vitro. The role of WNT family member 5A (WNT5A)/WNT family member 5A (WNT7A)/beta-catenin signaling was also investigated. BMSCs were isolated from a steroid-induced avascular necrosis of the femoral head (SANFH) rabbit model. The third-generation of BMSCs was used after identification. The results revealed obvious degeneration and necrosis in the SANFH rabbit model. AZA, TSA and TSA + AZA increased BMSC proliferation in a time-dependent fashion. AZA, TSA and TSA + AZA induced the cell cycle release from the G0/G1 phase and inhibited apoptosis in BMSCs. AZA, TSA and TSA + AZA treatment significantly decreased caspase-3 and caspase-9 activities. The treatment obviously increased the activity and relative mRNA expression of alkaline phosphatase. The treatment also significantly up-regulated the proteins associated with osteogenic differentiation, including osteocalcin and runt-related transcription factor 2 (RUNX2), and Wnt/beta-catenin signal transduction pathway-related proteins beta-catenin, WNT5A and WNT7A. The relative levels of Dickkopf-related protein 1 (an inhibitor of the canonical Wnt pathway) decreased remarkably. Notably, TSA + AZA treatment exhibited a stronger adjustment ability than either single treatment. Collectively, the present studies suggest that AZA, TSA and TSA + AZA promote cell proliferation and osteogenic differentiation in BMSCs, and these effects are potentially achieved via upregulation of WNT5A/WNT7A/b-catenin signaling.

Surgical and Non-Surgical Treatment for 3-Part and 4-Part Fractures of the Proximal Humerus: A Systematic Review of Overlapping Meta-Analyses.

This systematic review of overlapping meta-analyses was conducted to propose a principle to make decisions for comparing clinical safety and efficacy of surgical and non-surgical treatment for displaced 3-part and 4-part fractures of the proximal humerus. Three electronic databases (PubMed, EMBASE, and the Cochrane Library) were systematically searched to retrieve available published systematic reviews and meta-analyses comparing surgical versus non-surgical treatment for displaced 3-part and 4-part fractures of the proximal humerus. Ten meta-analyses were identified for this investigation. Based on the application of selection with the Jadad algorithm, a meta-analysis including 6 randomized clinical trials was selected for this systematic review, which demonstrated the best available evidence that no statistically significant differences were found in the Constant score, health-related quality of life, and mortality between surgical and non-surgical treatments for displaced 3-part and 4-part fractures of the proximal humerus; however, surgical treatment was associated with a significant increase in the incidence of reoperation. This systematic review of  overlapping meta-analyses reveals that although surgical treatment is more advantageous than and superior to non-surgical treatment for displaced 3-part and 4-part fractures of the proximal humerus, the former leads to a higher incidence of postoperative complications.

Transiliac Osteotomy in Surgical Management of Pelvic Post-Traumatic Malunions: A Retrospective Study.

While uncommon, post-traumatic pelvic malunions present reconstructive challenges and are associated with significant disability and financial burden. A transiliac osteotomy is a surgical technique useful to correct certain types of pelvic fracture malunions, and is only used when the correction of a limb-length discrepancy is the primary goal. This study aims to present our experience with this technique in the treatment of post-traumatic pelvic malunions. Eight patients who underwent transiliac osteotomies for post-traumatic pelvic malunions at our department from 2006 to 2011 were included in this study. We reviewed the clinical and radiographic results of these patients. By the time of their last follow-up, all osteotomy sites and iliac bone graft had healed with no evidence of internal fixation failure. Of the 3 patients who complained of preoperative posterior pain, 2 reported an improvement. All 8 patients noted the resolution of their lower back pain. At the time of their final follow-up, 4 patients could walk normally, 2 had a slight limp without a cane, 1 patient used a cane to help with standing and walking, and the final felt limited during ambulation with a cane. Limb-lengthening relative to preoperative measurements was 2.86 cm (2.2-3.0 cm) at the time of the last follow-up. Two patients were able to return to their previous jobs, 4 patients changed their jobs or engaged in light manual labor while the final 2 were able to perform activities of daily living but were unable to participate in work or labor. Three patients reported being "extremely satisfied" with their outcomes, 3 were "satisfied," and 2 were "unsatisfied." A transiliac osteotomy can be used to manage selected cases of post-traumatic pelvic malunions that are unable to be corrected with a traditional release and osteotomy. However, in these cases the correction of limb-length discrepancies should be the primary reconstructive goal.

Medial approach to treat humeral mid-shaft fractures: a retrospective study.

BACKGROUND: Plate fixation is the gold standard for diaphyseal fracture management, and the anterolateral approach is widely used by reconstructive surgeons. However, the outcomes of humeral shaft fracture fixation using a medial approach are rarely reported. The aim of this study is to explore the management and outcomes of humeral mid-shaft fractures fixed through a medial incision. METHODS: Thirty-four patients who sustained a humeral mid-shaft fracture and underwent an open-reduction internal fixation (ORIF) in our department between January 2010 and January 2013 were included in this study. Sixteen patients had an ORIF performed through a medial approach, while the remaining 18 were fixed through an anterolateral approach. Postoperative clinical and radiographic results were reviewed. RESULTS: There were no significant differences in the blood loss and the range of motion of the shoulder and elbow between the anterolateral and medial fixation groups. One patient in the medial group and two patients in the anterolateral group had radial nerve dysfunction that improved after 8, 3 and 6 weeks, respectively. All patients healed radiographically except one from the anterolateral group who underwent grafting and re-fixation for a non-union. No vascular injuries, infections, malunions, broken plates or loose screws were noted in either group. CONCLUSIONS: The medial approach to the humerus had equivalent outcomes to anterolateral fixation. It is an available choice for humeral mid-shaft fracture fixation in cases where there is no need to expose the radial nerve. The medial approach does not require a pre-bent plate and creates a large operative exposure. A well-hidden incision can also be designed, improving cosmetic outcomes. However, the medial approach is not suitable to proximal or distal humerus fractures.

Epigenetic regulation of BMP2 by 1,25-dihydroxyvitamin D3 through DNA methylation and histone modification.

Genetic hypercalciuric stone-forming (GHS) rats have increased intestinal Ca absorption, decreased renal tubule Ca reabsorption and low bone mass, all of which are mediated at least in part by elevated tissue levels of the vitamin D receptor (VDR). Both 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and bone morphogenetic protein 2 (BMP2) are critical for normal maintenance of bone metabolism and bone formation, respectively. The complex nature of bone cell regulation suggests a potential interaction of these two important regulators in GHS rats. In the present study, BMP2 expression is suppressed by the VDR-1,25(OH)2D3 complex in Bone Marrow Stromal Cells (BMSCs) from GHS and SD rat and in UMR-106 cell line. We used chromatin immunoprecipitation (ChIP) assays to identify VDR binding to only one of several potential binding sites within the BMP2 promoter regions. This negative region also mediates suppressor reporter gene activity. The molecular mechanisms underlying the down-regulation of BMP2 by 1,25(OH)2D3 were studied in vitro in BMSCs and UMR-106 cells using the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (DAC) and the histone deacetylase inhibitor trichostatin A (TSA). Both DAC and TSA activate BMP2 expression in combination with 1,25(OH)2D3. Bisulfite DNA pyrosequencing reveals 1,25(OH)2D3 to completely hypermethylate a single CpG site in the same BMP2 promoter region identified by the ChIP and reporter gene assays. ChIP assays also show that 1,25(OH)2D3 can increase the repressive histone mark H3K9me2 and reduce the acetylation of histone H3 at the same BMP2 promoter region. Taken together, our results indicate that 1,25(OH)2D3 binding to VDR down-regulates BMP2 gene expression in BMSCs and osteoblast-like UMR-106 cells by binding to the BMP2 promoter region. The mechanism of this 1,25(OH)2D3-induced transcriptional repression of BMP2 involves DNA methylation and histone modification. The study provides novel evidence that 1,25(OH)2D3 represses bone formation through down-regulating BMP2 expression both in vivo and in vitro.

Lumbopelvic fixation for multiplanar sacral fractures with spinopelvic instability.

Sacral fractures with both transverse and bilateral vertical fracture components are by definition multiplanar fractures, and often present with spinopelvic instability and cauda equina deficits. The treatment is challenging. Between 2006 and 2009, we treated nine such patients at our trauma centre. There were six men and three women, with a mean age of 32.2 years. Preoperative neurologic deficits were noted in seven patients; four patients had complete cauda equina paralysis, and three patients had incomplete cauda equina syndrome. All patients were treated using lumbopelvic instrumented fixation without other devices for their multiplanar sacral fractures. Six patients who had neurological deficits and sacral canal compression underwent decompression laminectomy. The mean postoperative follow-up time was 21.7 months (range, 14-32 months). All fractures went on to union without loss of reduction or hardware failure. The mean Gibbons score improved from 3.5 preoperatively to 2.3 postoperatively among the patients who underwent decompression laminectomy. Eight out of nine patients had fair or better results based on radiographic criteria and the Majeed pelvic fracture outcome score. Our experience suggests lumbopelvic fixation can be used for the treatment of multiplanar sacral fractures with spinopelvic instability with a low rate of complications. Neurologic improvement can be expected, but whether surgical decompression results in substantially better neurologic recovery than conservative treatment remains uncertain.