ABSTRACT
BACKGROUND: The femoral intramedul ary guides in total knee arthroplasty require high precision, complex operation, it is very important for prosthesis and joint function to choose more precise positioning method and determine the correct needle point. OBJECTIVE: To study the effect of needle point position on prosthesis arrangement when applying different femoral intramedul ary guides methods in total knee arthroplasty. METHODS: Total y 80 patients who received the treatment of total knee arthroplasty in Changshu No.1 People’s Hospital from January 2012 to July 2015 were selected and divided into test and control groups according to random number table (n=40/group). The patients in the test group accepted CT scan for femoral intramedul ary guides. The theoretical position of femoral intramedul ary guides entry point was marked using radiographic parameters. In the control group, the traditional total knee arthroplasty technology was used to mark the entry point of femoral intramedul ary guides. The needle point position when applying different femoral intramedul ary guide methods was observed. The effect of femoral intramedul ary guides on prosthesis arrangement in total knee arthroplasty was discussed. RESULTS AND CONCLUSION: Compared with the control group, the distance from entry point to femoral anatomic line on positive and lateral X-ray film in the test group was shorter, femoral prosthesis lateral angle and physiological valgus angle were closer to the theoretical value, distance from intersection of femur axis and femoral condyle to block center was shorter; the differences were statistical y significant (P < 0.05). These results demonstrate that compared with the traditional two-dimensional intramedul ary positioning, the needle point position of three-dimensional CT scan stimulative positioning is more accurate. The location more concentrates on within intercondylar fossa 2-5 mm, more front of intercondylar fossa 3-10 mm, three-dimensional CT scan stimulative positioning is a reliable choice for femoral intramedul ary guides.