Transcriptome profiling of digital flexor tendons after injury in a chicken model.

BACKGROUND: Modulation of tendon healing remains a challenge because of our limited understanding of the tendon repair process. Therefore, we performed the present study to provide a global perspective of the gene expression profiles of tendons after injury and identify the molecular signals driving the tendon repair process. RESULTS: The gene expression profiles of flexor digitorum profundus tendons in a chicken model were assayed on day 3, weeks 1, 2, 4, and 6 after injury using the Affymetrix microarray system. Principal component analysis (PCA) and hierarchical cluster analysis of the differentially expressed genes showed three distinct clusters corresponding to different phases of the tendon healing period. Gene ontology (GO) analysis identified regulation of cell proliferation and cell adhesion as the most enriched biological processes. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis revealed that the cytokine-cytokine receptor interaction and extracellular matrix (ECM)-receptor interaction pathways were the most impacted. Weighted gene co-expression network analysis (WGCNA) demonstrated four distinct patterns of gene expressions during tendon healing. Cell adhesion and ECM activities were mainly associated with genes with drastic increase in expression 6 weeks after injury. The protein-protein interaction (PPI) networks were constructed to identify the key signaling pathways and hub genes involved. CONCLUSIONS: The comprehensive analysis of the biological functions and interactions of the genes differentially expressed during tendon healing provides a valuable resource to understand the molecular mechanisms underlying tendon healing and to predict regulatory targets for the genetic engineering of tendon repair. Tendon healing, Adhesion, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, Weighted Gene Co-expression Network Analysis, Protein-protein Interaction.

[Comparison of the effect of total hip arthroplasty through mini invasive direct anterior approach during learning curve period and posterolateral approach for the treatment of femoral head necrosis].

OBJECTIVE: To compare clinical results of treating femoral head necrosis staged Ficat III or IV with total hip arthroplasty (THA) between mini invasive direct anterior approach (DAA) and posterolateral approach. METHODS: From January 2008 to December 2009, 48 patients with femoral head necrosis staged Ficat III or IV treated with THA were compared and analyzed. There were 21 patients in mini invasive direct anterior approach group including 11 males and 10 females with an average age of (65.2±4.3) years old;while there were 27 patients in posterolateral approach group including 16 males and 11 females with an average age of (63.6±4.0) years old. Operative time, blood loss during operation, bed rest time and complications of two groups were observed and compared. Acetabular abduction and stem shaft angle were measured 1 month after operation and compared between two groups. Postoperative Harris Hip scoring and VAS scoring were applied for evaluating hip function and pain at 1, 6 months and 5 years after operation respectively. RESULTS: All patients were followed up for 48 to 73 months with an average of 60.4 months. Operative time, blood loss in DAA group was (78.30±5.08) min, (351.30±21.46) ml, respectively, in posterolateral approach group was (75.61±10.60) min, (362.20±26.15) ml, and no significant differences between two groups. Bed rest time in DAA group was (2.05±1.10) days, better than that of in posterolateral approach which was (3.30±1.35) days. No significant differences were found between two groups in acetabular abduction and stem shaft angle at 1 month after operation. There was no significant differences between two groups in HHS and VAS score at 1, 6 months and 5 years after operation. There was 1 case with injury of ascending branch of the lateral circumflex femoral artery, 1 case with great trochanter fracture and 1 case with superficial infection in DAA group, 1 case with dislocation in posterolateral group. No prosthesis loosening occurred in two groups. CONCLUSIONS: Both DAA and posterolateral approach are effective in treating femoral head necrosis staged Ficat III or IV, and could obtain excellent outcomes. However, DAA seemed to has disadvantage in learing curve compared posteriolateral approach in complex cases.

[Failure of internal fixation on displaced femoral neck fractures in adults under fifty-five years old].

OBJECTIVE: To investigate the failure of internal fixation on displaced femoral neck fractures in adults under fifty-five years old retrospectively inorder to pay more attention to the treatment of these fractures. METHODS: From Junary 2007 to June 2010,18 failed cases of internal fixation on displaced femoral neck fractures in adults under fifty-five years old were treated,there were 13 males and 5 females with an average age of (48.0 +/- 6.0) years old ranging from 27 to 55. Among them, 17 patients were treated with cannulated screws and 1 patient was treated with intramedullary nail; 16 patients were diagnosed as osteonecrosis and 2 patients as osteonecrosis associated with nonunion. RESULTS: The average time from internal fixation to failure was 23 months (ranged, 8 to 32 months). The quality of fracture reduction in Garden index was poor. The Harris Hip Score was (56.0 +/- 12.5) (ranged,33 to 80). Eight cases of osteonecrosis and 2 cases of nonunion combinated osteonecrosis were received total hip arthroplasty. Hip resurfacing arthroplasty were performed for other 5 osteonecrosis. Because of no evident clinical symptoms,the other 3 cases received conservative treatment. The patients with total hip arthroplasty and hip resurfacing arthroplasty were followed-up for 34 months ranging from 12 to 53 months. After operation,the Harris score was (94.0 +/- 3.0) ranged 89 to 96. CONCLUSION: Osteonecrosis is a common complication after internal fixation on displaced femoral neck fracture in adults under fifty-five years old. More attention should be paid to the treatment of displaced femoral neck fracture in those patients.