Aimin Chen

Internal Fixation Versus Nonoperative Treatment for Displaced 3-Part or 4-Part Proximal Humeral Fractures in Elderly Patients: A Meta-Analysis of Randomized Controlled Trials

Background A few studies focused on open reduction and internal fixation (ORIF) or nonoperative treatment of displaced 3-part or 4-part proximal humeral fractures in elderly patients have been published, all of whom had a low number of patients. In this meta-analysis of randomized controlled trials (RCTs), we aimed to assess the effect of ORIF or nonoperative treatment of displaced 3-part or 4-part proximal humeral fractures in elderly patients on the clinical outcomes and re-evaluate of the potential benefits of conservative treatment. Methods We searched PubMed and the Cochrane Central Register of Controlled Trials databases for randomized controlled trials comparing ORIF and nonoperative treatment of displaced 3-part or 4-part proximal humeral fractures in elderly patients. Our outcome measures were the Constant scores. Results: Three randomized controlled trials with a total of 130 patients were identified and analyzed. The overall results based on fixed-effect model did not support the treatment of open reduction and internal fixation to improve the functional outcome when compared with nonoperative treatment for treating elderly patients with displaced 3-part or 4-part proximal humeral fractures (WMD −0.51, 95% CI: −7.25 to 6.22, P = 0.88, I2 = 0%). Conclusions Although our meta-analysis did not support the treatment of open reduction and internal fixation to improve the functional outcome when compared with nonoperative treatment for treating elderly patients with displaced 3-part or 4-part proximal humeral fractures, this result must be considered in the context of variable patient demographics. Only a limited recommendation can be made based on current data. Considering the limitations of included studies, a large, well designed trial that incorporates the evaluation of clinically relevant outcomes in participants with different underlying risks of shoulder function is required to more adequately assess the role for ORIF or nonoperative treatment.

Treatment of type C pilon fractures by external fixator combined with limited open reduction and absorbable internal fixation.

Introduction: This study was conducted to evaluate the clinical outcome of the treatment of type C pilon fractures by using an external fixator combined with limited open reduction and absorbable internal fixation. Patients and Methods: Twenty-five type C pilon fractures, including 4 open fractures, were included in this retrospective study. The procedure of first-stage manipulation and external fixation spanning the ankle joint was conducted as early as possible. For the second stage, the tibial and fibular fractures were reduced and fixed with absorbable screws or rods through a limited incision. Clinical and radiographic evaluations were performed. The American Orthopaedic Foot & Ankle Society score (AOFAS) was obtained for evaluation of function. Twenty-one patients were followed postoperatively for a minimum of 18 months. Results: The mean time of union was 4.8 months. Delayed union of the distal tibia occurred in 1 patient. Minor infection occurred in 8 patients and deep infection in 1 patient. No skin necrosis, malunion, loss of reduction, nonunion, or fixation failure was observed during the follow-up period. No hardware removal was needed, nor was adverse tissue reaction to the implants observed. An excellent or good AOFAS outcome was obtained in 81% (17/21) of the patients. Conclusions: External fixator combined with limited open reduction and absorbable internal fixation was a reliable treatment for closed and open AO/OTA type C pilon fractures of the distal tibia. Level of Evidence: Level IV, retrospective case series.

Circular RNA Atp9b, a competing endogenous RNA, regulates the progression of osteoarthritis by targeting miR-138-5p

Osteoarthritis (OA) is the most common joint disease and is mainly characterized by degradation of the articular cartilage. Recently, circular RNAs (circRNAs), novel noncoding RNAs with different biological functions and pathological implications, have been reported to be closely associated with various diseases. Growing evidence indicates that circRNAs act as competing endogenous RNAs (ceRNAs) that bind with microRNAs (miRNAs) and regulate their downstream functions. Here, we identified a new circRNA, circRNA_Atp9b, and further investigated its function in OA using a well-established mouse chondrocyte model. We demonstrated that circRNA_Atp9b expression was significantly up-regulated in mouse chondrocytes after stimulation with interleukin-1 beta (IL-1β), and that knockdown of circRNA_Atp9b promoted the expression of type II collagen while inhibiting the generation of MMP13, COX-2 and IL-6. Moreover, there was a negative correlation between the expression levels of circRNA_Atp9b and microRNA (miR)-138-5p, indicating that miR-138-5p also played a role in IL-1β-induced chondrocytes. Bioinformatics analysis predicted circRNA_Atp9b directly target miR-138-5p, which was validated by dual-luciferase assay. Further functional experiments revealed that down-regulation of miR-138-5p partly reversed the effects of circRNA_Atp9b on extracellular matrix (ECM) catabolism and inflammation. Taken together, these results suggest that circRNA_Atp9b regulates OA progression by modulating ECM catabolism and inflammation in chondrocytes via sponging miR-138-5p. Our findings provide novel insight into the regulatory mechanism of circRNA_Atp9b in OA and may contribute to establishing potential therapeutic strategies.

3D printing-assisted osteotomy treatment for the malunion of lateral tibial plateau fracture

INTRODUCTION Osteotomy and internal fixation are usually the most effective way to treat the malunion of lateral tibial plateau fractures, and the accuracy of the osteotomy is still a challenge for surgeons. This is a report of a series of prospectively study of osteotomy treatment for the malunion of lateral plateau fractures with the aid of 3D printing technology. METHODS A total of 7 patients with malunion of lateral tibial plateau fractures were enrolled in the study between September 2012 to September 2014 and completed follow up. CT image data were used for 3D reconstruction, and individually 3D printed models were used for accurate measurements and detail osteotomy procedures planning. Under the premeditated operation plan, the osteotomy operations were performed. Patients were invited for follow-up examinations at 2 and 6 weeks and then at intervals of 6 to 8 weeks until 12 months or more. RESULTS Mean age of the patients was 44 years (range 30-52 years), 3 cases were result of fall injuries, 2 were traffic accidents and 2 were sports injuries. Among the cases, one accompanied with craniocerebra trauma, one with pelvic fracture, one accompanied with both. According to the Schatzker Tibial Plateau classification, the original fracture type were 3 type I, 1 type II and 3 type III. The lateral tibial plateau collapse ranges from 4 mm-12mm, with an average of 9.4mm. All the operations were successfully completed, the average operation time was 77.1min (range 70-90 min), the average intraoperative blood loss was 121.4ml (range 90-180ml), the mean follow-up time was 14.4 months (range 12-18 months), and the average healing time of the osteotomy fragments was 12 weeks (range 11-13 weeks). The difference between preoperative and postoperative Rasmussen scores were statistically significant (P<0.05). All the patients were obtained functional recovery, with no complications. CONCLUSION 3D printing technology is helpful to accurately design osteotomy operation, reduce the risk of postoperative deformity, decrease intraoperative blood loss, shorten the operation time, and can effectively improve the treatment effect.

Repair and regeneration of lumbosacral nerve defects in rats with chitosan conduits containing bone marrow mesenchymal stem cells

OBJECTIVES Despite the great progress in surgical treatment of lumbosacral nerve injuries caused by high-energy trauma, functional recovery remains poor and insufficient. Bone marrow mesenchymal stem cells (BMSCs), which express neurotrophic factors and can also differentiate into nerve cells, have potential as an effective alternative therapy for lumbosacral nerve defects. The aim of the present study was to evaluate the functional recovery, nerve regeneration, motor neuron survival and apoptosis after lumbosacral nerve transection in rats receiving BMSC transplantation into the chitosan conduit. METHODS The right L4-L6 nerve roots of rats were transected and bridged with three 1-cm-long chitosan conduits, which were further injected with the BMSCs (MSC-treated group) or culture medium (DMEM group). The nerve regeneration and motor function recovery were assessed by the sciatic functional index (SFI) and analysed electrophysiologically and morphologically. RESULTS At 6 and 12 weeks after surgery, the SFI values in MSC-treated group were significantly higher than those in DMEM group (P≤0.05). The peak amplitude of CMAP (compound muscle action potential) and nerve conduction velocity in MSC-treated group were significantly higher than that in DMEM group (P≤0.01), while the latency of CMAP onset in MSC-treated group was significantly shorter than that in DMEM group (P≤0.01). The diameter of the myelinated fibres and thickness of the myelin sheath in MSC-treated group were significantly higher than those in DMEM group (P≤0.05). There was no difference in the number of motor neurons in the anterior horn of the spinal cord at 6 weeks post-operation (P>0.05), while the number of motor neurons was significantly greater in MSC-treated group than that in DMEM group at 12 weeks post-operation (P≤0.001). The number of apoptotic cells was also significantly lower (P≤0.01). CONCLUSIONS The results of the present study showed that BMSCs treatment improved lumbosacral nerve regeneration and motor function. In addition, our data suggested that BMSCs inhibited motor neuron apoptosis, and improved motor neuron function and survival in the anterior horn of the spinal cord.

Unaffected contralateral S1 transfer for the treatment of lumbosacral plexus avulsion

INTRODUCTION This study describes a new surgical strategy for lumbosacral plexus avulsion by transfer of the unaffected contralateral S1 nerve root. METHODS A surgical reconstruction of the sacral nerve was performed on a 10-year-old boy with left lumbosacral plexus avulsion. The unaffected S1 nerve root (right side) is severed extradurally for transfer. A 25-cm long nerve graft from the common peroneal nerve of the affected side was used as donor nerve. One end of the nerve graft was anastomosed to the proximal stump of the right-sided extradural S1 nerve. The distal end of the nerve graft was divided into two fascicles and anastomosed to the left-sided inferior gluteal nerve and the branch of the sciatic nerve innervating the left-sided hamstrings. RESULTS According to motor score of the British Medical Research Council (MRC) system, the strength of glutei and hamstrings improved to the level of M3 1.5 years after surgery. CONCLUSIONS The extradural S1 nerve root in the unaffected side can be considered as a suitable donor nerve for transfer in patients with root avulsion of the lumbar or sacral nerve plexus.

High-mobility group box 1 induces neuron autophagy in a rat spinal root avulsion model

Autophagy, a tightly regulated lysosome-dependent catabolic pathway, is implicated in various pathological states in the nervous system. High-mobility group box 1 (HMGB1) is an inflammatory mediator known to be released into the local microenvironment from damaged cells. However, whether autophagy is induced and exogenous HMGB1 is involved in the process of spinal root avulsion remain unclear. Here, we investigated the induction effect of autophagy and the possible role of HMGB1 during spinal root avulsion. It was found that autophagy was activated in the anterior horn of the spinal cord as represented by the increased expression of the autophagic marker microtubule-associated protein light chain 3-II (LC3-II), degradation of sequestosome 1 (p62), and formation of autophagosomes, and that autophagy was inhibited after intraperitoneal injection of anti-HMGB1-neutralizing antibodies in the rat spinal root avulsion model. In addition, HMGB1-induced autophagy and activated mitogen-activated protein kinases (MAPKs) in primary spinal neurons, including c-Jun N-terminal kinase (JNK), extracellular-signal-regulated kinase (ERK), and p38MAPK. Inhibition of JNK or ERK activity significantly blocked the effect of HMGB1-induced autophagy in primary spinal neurons. Finally, HMGB1-induced autophagy increased cell viability in primary spinal neurons under oxygen-glucose deprivation conditions. The above results suggest that HMGB1 is a critical regulator of autophagy and HMGB1-induced autophagy plays an important role in protecting spinal neurons against injury, which may provide new insights into the pathophysiological process of spinal root avulsion.

Retrograde versus antegrade intramedullary nailing for femoral fractures: a meta-analysis of randomized controlled trials.

Abstract Objectives: To conduct a meta-analysis of randomized controlled trials assessing the effect on clinical outcomes of intramedullary nailing for femoral fractures via a retrograde or antegrade approach. Data sources: Randomized controlled trials using PubMed, Embase, and the Cochrane Library databases. Study selection: We used the following search terms with no language or study type restrictions: femoral shaft fractures, internal fixation, treatment outcome, intramedullary nailing, and retrograde or antegrade approach. Data extraction: Two independent authors extracted the data and we assessed the quality of the included studies based on Jadad score; allocation concealment; similarity of baseline characteristics; eligibility criteria; blinding; completeness of follow-up; and intention-to-treat analysis. Our primary outcome measure was the union rate and the secondary outcome measures were nonunion, knee pain, and heterotopic ossification. A total of 240 patients from three randomized controlled trials were included. Data synthesis: Risk ratios (RRs) and 95% confidence intervals (CIs) were computed for dichotomous variables, and weighted mean differences and 95% CIs for continuous variables. Heterogeneity among studies was assessed using the I 2 statistic, with I 2 > 50% considered significant. If heterogeneity was not significant, a fixed effects model was chosen to assess the overall estimate. Otherwise, a random effects model was used. We used Egger’s regression asymmetry test and Begg’s adjusted-rank correlation to assess publication bias. Conclusions: Both retrograde and antegrade intramedullary nailing produced high union rates. We found no significant difference in union rate between the retrograde nailing group and the antegrade nailing group for femoral fractures (RR 1.02, 95% CI: 0.94–1.11, p = 0.59, I 2 = 0%).

Accurate segmental motor innervation of human lower-extremity skeletal muscles.

BackgroundThere is limited knowledge about accurate segmental motor innervation of the human lower extremity skeletal muscles. The aim of the present study was to explore the truth of segmental motor innervation of the lower extremity.MethodsIncluded in this study were 20 patients with unilateral fracture of the sacrum and sacral nerve injury, who underwent internal fixation and decompression of the sacral nerve in our hospital between June 2009 and January 2014. L4-S4 nerve roots of the uninjured side were stimulated during operation. Motor innervation was determined by stimulating the spinal nerves with supramaximal intensity.ResultsWe found the gluteus medius and the gluteus maximus were both mainly innervated by L5 and S1. In addition, the nerve fibres that innervated the extensor digitorum brevis, the abductor hallucis and the flexor digitorum brevis were mainly from S2 to S3.ConclusionsOur study provides the electrophysiological mapping of the segmental anatomy of the human lower extremity muscles, which should be clinically useful in helping the diagnosis and treatment of nerve injury and neuropathies.

External Fixation versus Unreamed Tibial Intramedullary Nailing for Open Tibial Fractures: A Meta-analysis of Randomized Controlled Trials

Controversy exists over whether the use of external fixation (EF) or unreamed tibial intramedullary nailing (UTN) is optimal for the treatment of open tibial fractures. The aim of this study was to compare clinical outcomes in terms of postoperative superficial and deep infection, malunion, delayed union, nonunion and hardware failure between these two treatment methods. So a systematic review and meta-analysis was performed. All available randomized controlled trials that compared the clinical results of EF to those of UTN were obtained and the reported numbers of citations for each observed item were extracted to perform data synthesis. Six published randomized controlled trials with a total of 407 cases fulfilled all inclusion criteria. Data analysis revealed that UTN reduced the incidence rates of superficial infection and malunion after fixation compared with EF. However, EF led to a significant reduction in hardware failure. For postoperative deep infection, delayed union and nonunion, the treatment effects were similar between these two groups. Therefore, we recommend UTN over EF for the management of open tibial fractures. However, patients’ postoperative weight bearing should be controlled to avoid hardware failure.