Distal cortical hypertrophy following total hip arthroplasty.

Through a retrospective evaluation of 1,683 consecutive total hip arthroplasties performed exclusively by the senior author, a progressive occurrence of distal cortical hypertrophy of the bone on the medial and/or lateral portion of the femur was noted in 58 hips. All patients with evidence of hypertrophy had age, sex, weight, prosthetic design and alignment, radiolucency, and calcar resorption noted. A control was established by randomly selecting an equal number of patients without distal cortical hypertrophy for direct statistical comparison. It was concluded that hypertrophy following total hip arthroplasty is a result of abnormal stress distribution in the loaded femur and is not an indication of pain or loosening. Women with the stainless steel T-28 prosthesis were the most prone to hypertrophy.