An avulsion fracture of the lesser trochanter in the absence of known or
appropriate antecedent trauma was the initial manifestation of unrecognized
metastatic malignant disease in the subtrochanteric area of four patients.
In three patients the fracture healed but a pathological subtrochanteric
fracture then occurred, and in one patient prophylactic nailing of the hip
was performed to prevent this fracture. A thorough search for occult
metastatic malignant disease should be made whenever this fracture occurs
in an adult. Prophylactic internal fixation to prevent or delay a
subsequent pathological subtrochanteric fracture seems worth while.