2023, Vol. 27 ›› Issue (31): 4949-4953

Effects of relative anatomical position characteristics between the iliac crest and femoral greater trochanter on intramedullary nail placement

Li Jing1, 2,   Ping Ruiyue3, Zhang Guoxu1, 2,   Xie Qijun1, 2,   Wang Zhonghao1, 2,   Wang Haizhou3, Chen Haiyun3, Qi Ji1, 3, 4   

Abstract: BACKGROUND: Proximal femoral nail anti-rotation is widely used in the treatment of femoral intertrochanteric fractures. Accurate screw placement angle and position can effectively improve the success rate of surgery and reduce the incidence of internal fixation-related complications.
OBJECTIVE: To investigate the relative anatomical positional relationship between the iliac crest and the greater trochanter of femur on intramedullary nail placement based on radiological measurements.
METHODS: 174 hip joints were examined in 87 normal adult pelvic anteroposterior radiographs in Orthopedic Clinic of Guangdong Provincial Hospital of Chinese Medicine. There were 50 males and 37 females at the age of (43.72±14.45) years. The distance between bilateral iliac crest line (La) and bilateral femoral trochanter line (Lb) was measured. The angle with the median pelvic axis (∠1), the angle between the anatomical axis of the femur and the median axis of the pelvis (∠2), and the neck-shaft angle (∠3) were measured. On the pelvic anteroposterior radiograph, the vertical line of the horizontal line of the pelvis was made through the lateral margin of the iliac crest. The exposure of the greater trochanter of the femur was distinguished according to the degree of exposure of the greater trochanter of the femur inside and outside the vertical line. Group I (52 hip joints, with a large degree of exposure) was outside the line, and Group II (122 hip joints, with a small degree of exposure) was inside the line. The iliac crest occlusion angle was Δ1=|∠1-∠2|, and according to the proximal femoral nail anti-rotation with a 5° proximal lateralization angle was grouped, with Δ1≤5° as group IIa (66 hips), and Δ1>5° as group IIb (56 hips).
RESULTS AND CONCLUSION: (1) The values of La, La/Lb and Δ1 in Group I were lower than those in Group II (P < 0.05); the value of La/Lb in Group IIa was higher than that in Group IIb (P < 0.05); the value of Δ1 in Group I was higher than that in Group IIa (P < 0.05) and lower than that in Group IIb (P < 0.05); the value of Lb in Group IIb was lower than that in Group I (P < 0.05) and higher than that in Group IIa (P < 0.05). (2) The results showed that the smaller the distance between the pelvic width and the bilateral femoral trochanters, the smaller the degree of occlusion, and the easier it was to enter the nail. The smaller the degree of iliac crest occlusion, the better for nail insertion was. There are quite a few people with iliac crest occlusion. If it is found that the iliac crest occlusion is obvious before the operation, it can be considered to increase the degree of adduction appropriately to facilitate nail insertion on the premise of maintaining anatomical reduction during positioning, which has guiding significance for clinical operation.

Key words: anatomy, iliac crest, greater trochanter, intramedullary nail, X-ray film