[Nitinol memory alloy two foot fixator with autologous cancellous bone grafting for old scaphoid fracture and nonunion].

ABSTRACT

OBJECTIVE: To summarize the effectiveness of nitinol memory alloy two foot fixator with autologous cancellous bone grafting in treating old scaphoid fracture and nonunion. METHODS: Between January 2013 and January 2017, 11 patients of old scaphoid fracture and nonunion were treated with nitinol memory alloy two foot fixator and autologous cancellous bone grafting. All patients were male with an average age of 26.1 years (range, 18-42 years). The fractures were caused by sport in 3 cases, falling in 7 cases, and a crashing object in 1 case. The interval between injury and operation was 6-18 months (mean, 8.9 months). Postoperative outcome measures included operation time, fracture healing time, grip strength, range of motion (ROM) of flexion, extension, ulnar deviation, and radial deviation, Mayo score, visual analogue scale (VAS) score, and the Disabilities of the Arm, Shoulder, and Hand (DASH) score. RESULTS: The operation time was 35-63 minutes (mean, 48 minutes). All incisions had primary healing with no infection and loosening or breakage of internal fixator. All patients were followed up 12-30 months (mean, 20.7 months). X-ray films showed that fracture healing was achieved in all patients with an average time of 15 weeks (range, 12-25 weeks). All internal fixators were removed after 10-12 months of operation (mean, 11.2 months). At last follow-up, the grip strength, ROMs of flexion, ulnar deviation, and radial deviation were superior to those before operation ( P<0.05), no significant difference was found in ROM of extension between pre- and post-operation ( t=0.229, P=0.824). There were significant differences in above indexes between affected and normal sides ( P<0.05). At last follow-up, the Mayo, VAS, DASH scores were also significantly superior to those before operation ( P<0.05). CONCLUSION: For the old scaphoid fracture and nonunion, Ni-Ti arched shape-memory alloy fixator and autologous cancellous bone grafting can obtain good effectiveness, which is an effective treatment.