Guoxin Nan

Meta-analysis of the outcomes of intramedullary nailing and plate fixation of humeral shaft fractures

OBJECTIVE The purpose of this study is to compare the outcomes of intramedullary nailing and plate fixation in the treatment of humeral shaft fractures using meta-analysis. METHODS PubMed, MEDLINE, EMBASE, the Cochrane Controlled Clinical Trials Register (CCTR) databases were searched for studies that investigated the efficacy of intramedullary nailing and plate fixation in the management of humeral shaft fractures. Delayed healing rate, nonunion, postoperative infection and radial nerve paralysis were key outcomes of interest. Data were searched within the time period of July 1990 through September 2012. The statistical software RevMan 5.0 was used to analyze the statistical significance of the results. RESULTS Total 459 cases of patients in 10 literature, including 231 cases of plate group and 228 cases of the intramedullary nailing groups were collected. The results of meta-analysis showed that delayed healing rate of humeral shaft fractures was lower in plate fixation compared with intramedullary nailing (RR = 2.64, 95% CI (1.08, 6.49), P < 0.05). No statistically significant difference in nonunion, postoperative infections, radial nerve paralysis and other complications was identified between nailing and plate fixation groups (P > 0.05). CONCLUSIONS In general, the effect size of intramedullary nailing may be comparable to that of plate fixation in the terms of nonunion, postoperative infections, radial nerve paralysis. The only slightly difference was identified in the event of delayed healing rate.

AP2α transcriptional activity is essential for retinoid-induced neuronal differentiation of mesenchymal stem cells

Pre-activation of the retinoid signaling pathway by all-trans retinoic acid facilitates neuronal differentiation of mesenchymal stem cells. Using protein/DNA based screening assays, we identified activator protein 2α as an important downstream target of all-trans retinoic acid. Although all-trans retinoic acid treatment significantly increased activator protein 2α transcriptional activity, it did not affect its expression. Inhibition of activator protein 2α with dominant-negative mutants reduced ATRA-induced differentiation of mesenchymal stem cells into neurons and reversed its associated functional recovery of memory impairment in the cell-based treatment of a hypoxic-ischemic brain damage rat model. Dominant-negative mutants of activator protein 2α inhibited the expression of neuronal markers which were induced by retinoic acid receptor β activation. All-trans retinoic acid treatment increased phosphorylation of activator protein 2α and resulted in its nuclear translocation. This was blocked by siRNA-mediated knockdown of retinoic acid receptor β. Furthermore, we found that retinoic acid receptor β directly interacted with activator protein 2α. In summary, the regulation of all-trans retinoic acid on activator protein 2α transcriptional activity was mediated by activation of retinoic acid receptor β and subsequent phosphorylation and nuclear translocation of activator protein 2α. Our results strongly suggest that activator protein 2α transcriptional activity is essential for all-trans retinoic acid-induced neuronal differentiation of mesenchymal stem cells.

Visualization of the wrist ganglion capsule by methylene blue staining as an aid for complete resection in children

PURPOSE To evaluate the effectiveness of methylene blue staining during ganglion resection in children, to assess ganglion resection and minimize recurrence. METHODS From August 2007 to March 2011, 36 children with dorsal or volar wrist ganglions with an average size of 2 cm (range, 1-4 cm), including 5 recurrent cases, underwent resection performed with intraoperative methylene blue marking of the cyst wall. RESULTS We found recurrence in one patient after 2 years; no obvious complications were observed in any patient. CONCLUSIONS Methylene blue staining of the ganglion during resection may be helpful for achieving complete resection. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic II.

Pulmonary edema and hemorrhage after acute spinal cord injury in rats

BACKGROUND CONTEXT Respiratory complications are a major cause of morbidity and mortality during the first days after acute spinal cord injury (ASCI). However, the pathophysiology of respiratory insufficiency resulting from spinal cord injury that involves lower levels is less well understood. PURPOSE The aim of the present study was to investigate pulmonary pathophysiology after ASCI. STUDY DESIGN This is an experimental animal study of ASCI investigating pulmonary pathophysiology after ASCI. METHODS Eighty-four (N=84) rats were divided into two groups: a sham surgery (n=42) and an injury group (n=42). In the injury group, ASCI was induced at the level of the tenth thoracic vertebra by a modified Allen method. Rats were sacrificed 6 hours, 12 hours, 24 hours, 3 days, 1 week, 2 weeks, and 4 weeks after surgery. Pulmonary edema was assessed by calculating the ratio of the wet-to-dry lung weight (W:D). Pulmonary edema and hemorrhage were evaluated by observing gross and microscopic morphology. The study was funded by Natural Science Foundation of China (NSFC, 81272172). The funder of the present study had no capacity to influence the scholarly conduct of the research, interpretation of results, or dissemination of study outcomes. RESULTS In the injury group, W:D was significantly increased 12 hours after surgery compared with the sham surgery group; W:D peaked 3 days after ASCI (p<.05). Gross morphologic observations showed hemorrhagic lesions on the lung tissue 12 hours after ASCI and pulmonary edema 24 hours after ASCI. Pulmonary edema peaked 3 days after ASCI and was obviously decreased 1 week after ASCI. Hemorrhage was apparent until 2 weeks after ASCI. Light microscopy showed congestion of pulmonary capillaries 6 hours after ASCI. The pulmonary alveoli were filled with erythrocytes and serous extravasate 12 hours after ASCI. Hemorrhage and edema were observed in the interstitium and lung alveoli 24 hours after ASCI. CONCLUSIONS Early pathologic changes such as pulmonary congestion, hemorrhage, and edema after injury may be the basis for early respiratory dysfunction following ASCI.

Cystic Adventitial Disease of Popliteal Artery in a Boy Younger than 6 Years Old.

1Department II of Orthopedics, Childrens Hospital of Chongqing Medical University; Stem Cell Biology and Therapy Laboratory & Key Laboratory of Child Development and Disorders; Key Laboratory of Pediatrics in Chongqing (CSTC2009CA5002), Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China 2Department 8, Institute of Research Surgery, Daping Hospital, Third Military Medical University, Chongqing, China 3Department of Anesthesiology, General Hospital of Chengdu Military Command, Chengdu, China 4Traumatic Center, Institute of Research Surgery, Daping Hospital, Third Military Medical University, Chongqing, China These authors contributed equally to this study

Causes of secondary deformity after surgery to correct Wassel type IV-D thumb duplication.

This study was undertaken to document the causes of secondary deformities after surgery for correction of Wassel type IV-D thumb duplication. We carefully dissected and observed the flexor pollicis longus, and bone and joint anatomy in eight patients with secondary deformities after surgical correction. We transferred the flexor pollicis longus and thenar muscle attachments, reconstructed the A2 pulley, released and tightened the joint capsule, and performed osteotomies to correct skeletal malalignment. Kirschner wire fixation was used for 4–5 weeks, followed by brace fixation for 3 months. Patients were followed up for 13–34 months (mean 20 months). According to the Tada scores, the outcomes were good in six patients, and fair and poor in one patient each. The main causes of the secondary deformities were failure to reconstruct the A2 pulley, to transfer the flexor pollicis longus and thenar muscles, and incomplete resection of the radial metacarpal head. Brace fixation after Kirschner wire removal is crucial in preventing secondary deformities. Level of evidence: IV

The kinetics of autophagy in the lung following acute spinal cord injury in rats

BACKGROUND CONTEXT Lung injury is a major cause of respiratory complications following an acute spinal cord injury (ASCI), which are associated with a high mortality rate. Autophagy has been shown to be involved in a variety of lung diseases; however, whether autophagy is activated in the lung following ASCI remains unknown. PURPOSE The objective of this study was to investigate the induction of autophagy in the lung after ASCI. STUDY DESIGN This is an experimental animal study of ASCI investigating kinetics of autophagy in the lung following ASCI. METHODS One hundred and forty-four rats (N=144) were divided into two groups: (1) a sham (n=72) and (2) an injury group (n=72). Allens method was used to induce an injury at the level of the 10th thoracic vertebra. Rats were sacrificed at 6, 12, 24, 48, and 72 hours, 1 week, and 2 weeks after surgery. Lung pathology and apoptosis were assessed to determine the level of damage in the lung. LC3, RAB7, P62, and Beclin 1 were used to detect the induction of autophagy. The study was funded by the Natural Science Foundation of China (NSFC,81272172); National Key Specialty Construction of Clinical Projects of China (#2013-544). The funder of the present study had no capacity to influence the scholarly conduct of the research, interpretation of results, or dissemination of study outcomes. RESULTS In the injury group, pathologic changes (i.e., pulmonary congestion, hemorrhage, inflammatory exudation, and alveolar collapse) occurred within the lung tissue within 72 hours after ASCI. Apoptosis of the lung cells gradually increased and peaked 72 hours after ASCI. Within 24 hours of ASCI, LC3 expression decreased, recovered, and gradually increased from 24 hours to 72 hours. As RAB7 decreased, P62 increased, and the ratio of RAB7/LC3 significantly decreased. CONCLUSIONS After ASCI, autophagy in the injured lung underwent dynamic changes, as early autophagosome formation decreased and late autophagosomes accumulated; thus, autophagy is in a state of inhibition.

The anatomy of Wassel type IV-D thumb duplication

We describe Wassel type IV-D thumb duplication anatomy after surgery on 11 affected children (12 hands, seven boys (eight hands) and four girls). We studied the structure and course of the flexor pollicis longus tendon and its action at the joint. Four patients had secondary deformity associated with an absent A2 pulley and a tendon that clung to the radial side of a small thumb. In patients with primary deformity, the flexor tendon sheath became membranous in the A2 area and attached to neighbouring sites on the opposite side of the proximal phalanx. In the proximal A2 area, the tendon divided – one division attached on the ulnar side of the distal phalanx base; the other, the base of the radial side. There was slight ulnar angulation of the distal phalanx on the radial portion of the duplication and slight ulnar angulation on the radial portion. Level of evidence: V

Internal Fixation With Absorbable Rods for the Treatment of Displaced Radial Neck Fractures in Children.

Background: The treatment of radial neck fractures with complete displacement or severe displacement and an angle of >30 degrees is controversial. The currently used methods, including the Metaizeau technique, are associated with drawbacks such as imperfect reduction, epiphyseal damage, and delayed functional recovery. To overcome these drawbacks, we used absorbable rod fixation followed by early functional training for the treatment of displaced radial neck fractures in children. Methods: In this study, 68 patients (age, 4 to 12 y; average, 8.4 y; average angle, 58 degrees; average displacement, 53%) with radial neck fractures with Salter-Harris grades II to IV underwent lateral elbow open reduction and absorbable rod fixation. At 3 weeks postoperatively, the patients’ plaster casts were removed, and functional training was started. Results: Anatomic reduction was achieved in all patients. We followed-up 68 patients for 6 months to 4 years (average, 41 mo). No cases of radial nerve injury, radial bone necrosis, myositis ossificans, and postoperative infection were observed. The functional recovery was “excellent” in 43 patients, “good” in 13 patients, “average” in 12 patients, and “bad” in 0 patients, according to the Morrey evaluation standard. Conclusion: Open reduction with absorbable rod fixation for the treatment of displaced radial neck fractures in children was feasible and was a choice in children. Level of Evidence: Therapeutic II.

Using methylene blue as a marker to find and remove tiny metallic foreign bodies embedded in the soft tissues of children: A randomised controlled trial

BACKGROUND Embedment of metallic foreign bodies in the soft tissues is commonly encountered in the emergency room. Most foreign bodies are easily removed, but removal is difficult if the foreign body is very small or deeply embedded. OBJECTIVE To determine the usefulness of methylene blue staining in the surgical removal of tiny metallic foreign bodies embedded in the soft tissue. METHODS This prospective study involved 41 children treated between May 2007 and May 2012. The patients were randomly divided into a methylene blue group and a control group. In the control group, foreign bodies were located using a C-arm and removed via direct incision. In the methylene blue group, foreign bodies were located using a C-arm, marked with an injection of methylene blue and then removed surgically. The clinical outcomes, complications, operation time, surgical success rate, incision length, frequency of C-arm use, and length and depth of the foreign body were compared between the two groups. RESULTS The surgical success rate was significantly higher in the methylene blue group. The average operation time was significantly shorter in the methylene blue group. The C-arm was used significantly less frequently in the methylene blue group than in the control group. The incision length was significantly shorter in the methylene blue group than in the control group. CONCLUSIONS Methylene blue staining facilitated the location and removal of tiny metallic foreign bodies from the soft tissue, and significantly reduced operation time, incision length and radiation exposure compared to the conventional method.