Clinical consequences of stress shielding after porous-coated total hip arthroplasty.
From a series of 223 extensively porous-coated total hip arthroplasties, 208 hips had radiographic followup at a minimum of 2 years, which could be evaluated for radiographic evidence of stress-shielding. These patients had a mean 13.9-year followup (range, 2-18 years). We compared the outcome of 48 total hip arthroplasties that had radiographically evident stress-shielding with 160 total hip arthroplasties that did not have radiographically visible stress-shielding or that had less severe stress-shielding. Stress-shielding was more likely in females, patients with a low cortical index, and patients with larger stems. At the most recent followup, patients with stress-shielding had a lower mean walking score than patients without stress-shielding and less osteolysis. No patients with stress-shielding had femoral loosening, implant fractures, or loss of porous coating. The revision rate was 13% (six hips) among hips with stress-shielding and 21% (33 hips) among hips without stress-shielding. Fifteen-year survivorship was 93% among hips with stress-shielding and 77% among hips without stress-shielding. Stress-shielding did not produce adverse consequences in these extensively porous-coated total hip arthroplasties.
Engh
C Anderson
CA
Anderson Orthopaedic Research Institute, PO Box 7088, Alexandria, VA 22307, USA.
Young
Anthony M
AM
Engh
Charles A
CA
Hopper
Robert H
RH
D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D013314:Stress, Mechanical; D013499:Surface Properties