X. Shuogui, Second Military Medical University, Shanghai, China

Summary: Abstract Objective To analyze the biomechanical properties of Nitinol Patellar ConcentratoriNT-PCjin treatment of comminuted patellar fracture and to evaluate its clinical therapeutic outcomes. Methods In the biomechanical study, the tridimensional photoelastic patellar model made of epoxy resin was produced by precise cast molding. The model was then loaded with Nitinol Patellar Connector and frozen. After layer photographing and tracing the stress value of every internal node in the model was evaluated by the iterative method. In the clinical study, stress values of 29 cases of comminuted patellar fracture were treated with NT-PC. Results In the biomechanical study, stress values of 1262 modes cattered on 12 layers were obtained. The stress distribution indicated that an overall stress field was yielded when the Nitinol Patellar model. In the clinical study, the other 25 patients got and average follow-up of 22 months(10-50months).The X-ray showed that 23 cases got anatomical reduction of the articular surface. The injured knee joints achieved 90 degree flexion in an average of 3.2 weeks and achieved the same scope of flexion and extension as the healthy one in an average of 6.8 weeks. According to Bostman clinical grading scale.22 cases were rated as excellent,3 cases were good, and the excellent and good rate was 100%. Conclusion The NT-PC can produce and overall memory stress field so that it has a distinctive therapeutic effect on comminuted patellar fractures. Key words: Nitinol patellar concentrator; Patella fracture; Biomechanics; Fracture fixation, internal; Tridimensional photoelasticity