Costa CR, Johnson AJ, Naziri Q, Mont MA.

2011 – Source Rubin Institute for Advanced Orthopedics, Sinai Hospital,
Baltimore, Maryland 21215, USA.

Abstract

INTRODUCTION:

Metal-on-metal hip resurfacing has provided an alternative to standard total hip
arthroplasty in younger, more active patients. However, detractors argue that
many of the benefits of resurfacing can be obtained with the use of larger
femoral heads. The purported advantages of the resurfacing procedure include
preservation of femoral bone stock, increased range of motion, decreased
dislocation rate, excellent performance in high-activity patients, and a
potentially easier revision than total hip arthroplasty. The purpose of this
study was to examine the outcomes of patients who had hip resurfacing and to
compare them to all total hip arthroplasty procedures performed during the same
time period.

MATERIALS AND METHODS:

In November 2007, the senior investigator (MAM), a high-volume joint
arthroplasty surgeon, who had exceeded all resurfacing learning curves,
transitioned to a new hip resurfacing system. The study cohort of 67 resurfacing
patients (73 hips) had a mean age of 51 years (range, 21 to 84 years), consisted
of 63 males and 4 females, had a mean body mass index of 28 kg/m2 (range, 20 to
47 kg/m2), and had a minimum 2-year follow-up. Revision and complication rates
were determined, as well as clinical outcomes using various clinical rating
systems, including Harris hip scores. These outcomes were compared to another
cohort of 137 standard primary total hip arthroplasties performed during the
same time period.

RESULTS:

Survivorship in the hip resurfacing cohort was 100%, compared with 98% in the
total hip arthroplasty group (p = 0.55). The three failures were comprised of
one peri-prosthetic fracture treated with a femoral component revision and two
cases of acetabular loosening, for which the acetabular component only was
revised. Following revision, all patients were doing well at the most recent
follow-up of 2 years. One patient who underwent resurfacing arthroplasty
developed a right sciatic nerve palsy that was treated with nerve decompression.
The patient regained full motor and sensory function and was doing well at the
most recent follow-up. The mean Harris hip score in the resurfacing patients
improved from 32 points (range, 18 to 45) to 97 points (range, 70 to 100), at a
mean of 30 months (range, 24 to 37) follow-up.

CONCLUSION:

Excellent results continue to be demonstrated with hip resurfacing systems, with
equal, early survivorship when compared to total hip arthroplasty. For patients
who meet the appropriate selection criteria and in the hands of an experienced,
high-volume arthroplasty surgeon hip resurfacing provides excellent early
results.