Trochanteric bursitis

The trochanteric bursa rests between the greater trochanter and the iliotibial track.  The bursa is a fluid filled sac, which helps lubricate ligaments around the greater trochanter bone. Inflammation of this bursa can cause excessive pain in the hip area during hip flexion and extension. Pain may radiate down the lateral leg as far as the ankle and simulate sciatica. 

Pathogenesis:  

The greater trochanter, the bursa and the iliotibial track are located subcutaneously, and inflammation of the bursa can be caused by direct contusion to the area. This can be seen in contact sports, like football or ice hockey. Inflammation of the trochanteric bursa is also common in running sports. In these cases the bursitis is a result of excessive friction between the bony greater trochanter and the iliotibial track as they pass over each other during hip flexion and extension.