For the purpose of solving the problem that too large pole tip recession （PTR） is produced in magnetic rigid disk heads by mechanical polishing, a chemical mechanical nano-grinding experiment is performed by using a...For the purpose of solving the problem that too large pole tip recession （PTR） is produced in magnetic rigid disk heads by mechanical polishing, a chemical mechanical nano-grinding experiment is performed by using a float-piece polisher with a tin plate to achieve a more plane and smoother surface. A basal solution, addition agents and a range of pH value are suitably selected to find a kind of slurry, with which the PTR can be controlled on sub-nanometer scale and the giant magnetic resistance （GMR） corrosion and electrostatic damage （ESD） can be avoided. Moreover, the cause that TiC protrudes from the substrate surface of the heads is studied. The appropriate shape and size of diamond abrasive are selected according to the chemical activation of A1203 and TiC in the same slurry. In this way, the chemical and mechanical interactions are optimized and the optimal surface that has small PTR and TiC asperity is achieved. Ultimatily, the chemical mechanical nano-grinding in combination with mechanical nano-grinding is adopted. Sub-nanometer PTR is achieved and the TiC asperity is eliminated by the chemical mechanical nano-grinding with large size ofmonocrystalline followed by mechanical nano-grinding with smalle polycrystalline diamonds.展开更多
Radial head dislocation associated with an ipsilateral radial shaft fracture is a rare lesion, even more so for open lesions. Few cases have been found in the literature. We report this case due to its exceptional nat...Radial head dislocation associated with an ipsilateral radial shaft fracture is a rare lesion, even more so for open lesions. Few cases have been found in the literature. We report this case due to its exceptional nature and discuss the mechanism of onset. A twenty-five-year-old patient presented with a dislocation of the radial head associated with a GUSTILO ANDERSON type II open fracture of the radial shaft following an occupational accident. He was managed twenty-four hours after the trauma. The mechanism was a direct blow. The dislocation was reduced by external manoeuvre following open reduction of the radial shaft. The fracture was stabilized by two Kirschner wires following reduction. The result at 12 months was satisfactory from a clinical and radiological standpoint.展开更多
BACKGROUND Traumatic radial head dislocation(RHD)is a well-described injury in the pediatric population.It is usually associated with an injury to the ulna in Monteggia fracture-dislocation,although it can occur as an...BACKGROUND Traumatic radial head dislocation(RHD)is a well-described injury in the pediatric population.It is usually associated with an injury to the ulna in Monteggia fracture-dislocation,although it can occur as an isolated injury.Traumatic RHD with ipsilateral radial shaft fracture has rarely been reported.Delayed RHD secondary to the malunion of an isolated radial shaft fracture is extremely rare.CASE SUMMARY We report a 9-year-old boy with limited pronation of the right elbow.The patient was diagnosed with delayed RHD associated with the malunion of a distal radial fracture.Since the annular ligament was disrupted with forearm rotation causing subluxation of the radial head,a modified double-strip Bell Tawse procedure was performed to reconstruct the annular ligament without corrective osteotomy for the malunited site.Four years after surgery,the angulation deformity of the distal radius was corrected with the restoration of the normal curvature of the radius.There was no recurrence of RHD.CONCLUSION Annular ligament reconstruction without corrective osteotomy could reduce RHD and restore the normal curve of the radial shaft in children with delayed dislocation of the radial head associated with malunion of the radial shaft.Annular reconstruction using double triceps tendon strips might be useful for maintaining a more stable reduction by augmenting anterolateral parts.展开更多
基金National Natural Science Foundation of China(No. 50390061).
文摘For the purpose of solving the problem that too large pole tip recession （PTR） is produced in magnetic rigid disk heads by mechanical polishing, a chemical mechanical nano-grinding experiment is performed by using a float-piece polisher with a tin plate to achieve a more plane and smoother surface. A basal solution, addition agents and a range of pH value are suitably selected to find a kind of slurry, with which the PTR can be controlled on sub-nanometer scale and the giant magnetic resistance （GMR） corrosion and electrostatic damage （ESD） can be avoided. Moreover, the cause that TiC protrudes from the substrate surface of the heads is studied. The appropriate shape and size of diamond abrasive are selected according to the chemical activation of A1203 and TiC in the same slurry. In this way, the chemical and mechanical interactions are optimized and the optimal surface that has small PTR and TiC asperity is achieved. Ultimatily, the chemical mechanical nano-grinding in combination with mechanical nano-grinding is adopted. Sub-nanometer PTR is achieved and the TiC asperity is eliminated by the chemical mechanical nano-grinding with large size ofmonocrystalline followed by mechanical nano-grinding with smalle polycrystalline diamonds.
文摘Radial head dislocation associated with an ipsilateral radial shaft fracture is a rare lesion, even more so for open lesions. Few cases have been found in the literature. We report this case due to its exceptional nature and discuss the mechanism of onset. A twenty-five-year-old patient presented with a dislocation of the radial head associated with a GUSTILO ANDERSON type II open fracture of the radial shaft following an occupational accident. He was managed twenty-four hours after the trauma. The mechanism was a direct blow. The dislocation was reduced by external manoeuvre following open reduction of the radial shaft. The fracture was stabilized by two Kirschner wires following reduction. The result at 12 months was satisfactory from a clinical and radiological standpoint.
文摘BACKGROUND Traumatic radial head dislocation(RHD)is a well-described injury in the pediatric population.It is usually associated with an injury to the ulna in Monteggia fracture-dislocation,although it can occur as an isolated injury.Traumatic RHD with ipsilateral radial shaft fracture has rarely been reported.Delayed RHD secondary to the malunion of an isolated radial shaft fracture is extremely rare.CASE SUMMARY We report a 9-year-old boy with limited pronation of the right elbow.The patient was diagnosed with delayed RHD associated with the malunion of a distal radial fracture.Since the annular ligament was disrupted with forearm rotation causing subluxation of the radial head,a modified double-strip Bell Tawse procedure was performed to reconstruct the annular ligament without corrective osteotomy for the malunited site.Four years after surgery,the angulation deformity of the distal radius was corrected with the restoration of the normal curvature of the radius.There was no recurrence of RHD.CONCLUSION Annular ligament reconstruction without corrective osteotomy could reduce RHD and restore the normal curve of the radial shaft in children with delayed dislocation of the radial head associated with malunion of the radial shaft.Annular reconstruction using double triceps tendon strips might be useful for maintaining a more stable reduction by augmenting anterolateral parts.
