The nutrient artery canal of the femur: a radiological study in patients with primary total hip replacement.

OBJECTIVE

Plain antero-posterior and lateral radiographs of the femur often show radiolucent lines, which may reflect the canal of a nutrient artery. In patients who have undergone total hip replacement these radiolucent lines must be differentiated from fractures caused by bursting of the shaft during the procedure.

DESIGN AND PATIENTS

In a retrospective radiological study 129 extremities of 95 patients with cementless primary hip prostheses were examined for radiolucent lines. Pre- and postoperative antero-posterior and lateral radiographs were analyzed.

RESULTS

In 34 of 129 extremities (26.4%) radiolucent lines compatible with a nutrient artery canal were detected, 14 of which (10.9% overall) were seen on lateral radiographs. In 11 of 129 extremities (8.5%) a nutrient artery canal was detected only on the antero-posterior views, while in 9 of 129 extremities (7.0%) it was well defined in both projections. One patient (0.8%) presented with a fracture postoperatively, which was radiologically distinct from a nutrient artery canal. The distance between the tip of the greater trochanter and the proximal end of the nutrient artery canal was 170+/-25 mm; the canal length was 27+/-9 mm.

CONCLUSION

Nutrient artery canals are often seen radiologically on pre- and postoperative radiographs down to the mid-shaft level and should be routinely recorded.