Optimizing patient selection and outcomes with total hip resurfacing.

Short-term failures of total hip resurfacing have been related to specific characteristics of the proximal femur. A radiographic arthritic hip grading scale was used to assess four characteristics of the proximal femur: bone density, shape, biomechanics, and focal bone defects. Hips with no unfavorable characteristics were Grade A, hips with one unfavorable characteristic were Grade B, hips with two unfavorable characteristics were Grade C, hips with three unfavorable characteristics were Grade D, and hips with four unfavorable characteristics were Grade F. One hundred forty-seven consecutive hips were treated with metal-on-metal resurfacing by a single surgeon. There were no femoral neck fractures. Of the 91 hips eligible for a minimum 2 year followup, 90% were Grades A or B, 10% were Grade C, and none were Grades D or F. With a minimum 2-year followup, arthritic hip grading was associated with preoperative Harris hip score, occurrence of mild to moderate postoperative pain, preoperative and postoperative range of motion, preoperative and postoperative hip center of rotation, preoperative and postoperative horizontal femoral offset, preoperative and postoperative limb length discrepancy, and acetabular radiolucencies. Hips with a lesser degree of secondary arthritic changes have a higher arthritic hip grade and better outcomes with total hip resurfacing. Relatively strict selection criteria for resurfacing were associated with a low occurrence of short-term failures. Level of Evidence: Prognostic study, Level II (retrospective study). See the Guidelines for Authors for a complete description of levels of evidence.