ABSTRACT
OBJECTIVE: To compare the clinical efficacy of open debridement screw fixation combined with bone grafting, percutaneous screw fixation, and percutaneous screw fixation combined with injection of platelet-rich plasma (PRP) for the treatment of Slade and Dodds Grade III to IV scaphoid nonunion (SNU). METHODS: This retrospective study included patients with Grade III (25 patients) and Grade IV (28 patients) SNU. They were treated with open surgery bone grafting and internal fixation (group A), percutaneous screw fixation (group B) or percutaneous screw fixation and PRP injection (group C) from January 2015 to May 2020. The fracture consolidation rate, VAS score, and Mayo wrist function score were compared across the three groups. RESULTS: The consolidation rate was not significantly different among the three groups for both Grade III and IV SNU. However, patients in group C reported significantly less pain and better wrist function 7 days after surgery compared to group A and B, for both nonunion grades. At 3 months after surgery, group C had significantly better VAS and Mayo wrist scores compared to group A for both nonunion grades, and compared to group B for Grade IV SNU. At 6 and 12 months after surgery, patients with Grade IV SNU in groups A and C had significantly better VAS and Mayo wrist scores compared to group B. CONCLUSION: This study suggests that percutaneous screw fixation with PRP injection could be a more effective method for treating Grade IV SNU. This approach may reduce postoperative wrist pain and improve wrist function in the early stages after surgery for patients with both Grade III and IV SNU. TYPE OF STUDY/LEVEL OF EVIDENCE: IV.
Subject(s)
Fractures, Bone , Fractures, Ununited , Scaphoid Bone , Humans , Retrospective Studies , Fractures, Ununited/diagnostic imaging , Fractures, Ununited/surgery , Scaphoid Bone/diagnostic imaging , Scaphoid Bone/surgery , Fracture Fixation, Internal/adverse effects , Fracture Fixation, Internal/methods , Treatment Outcome , Pain, Postoperative , Bone Transplantation/methodsABSTRACT
In this study, the uniaxial compression of random orientation ZK60 Mg alloy to different strains was performed at room temperature. The microstructure evolution was characterized mainly using electron backscattered diffraction (EBSD), and the mechanical property was evaluated by the Vickers hardness test. During compression, extension twins nucleated, grew, and engulfed the grain. Twins form a texture with the c-axis parallel to the compression direction. With the massive nucleation and expansion of extension twins during compression, the twin boundary (TB) brought the grain refinement, and the twin boundary-dislocation interaction significantly increased the strain hardening rate of ZK60 Mg alloy, both leading to its significantly increasement of the hardness.