A prospective review of 303 cementless universal cups with emphasis on wear as the cause of failure.
Three hundred thirteen primary uncemented total hip arthroplasties were performed in a 20-month period using Universal cups and Taperloc stems with titanium heads.  The follow-up period was 2 to 5 years and 303 cups were measured radiographically for polyethylene wear, demarcation, osteolysis, and migration.  Analysis was performed clinically, radiographically, and via inspection at revision. Twenty-three cups (7.5%) had greater than 0.5 mm polyethylene wear. Eleven of these loosened radiographically (4%) and eight (3%) required revision.  All cup failures showed evidence of polyethylene wear as a contributory cause of failure.  The average rate of wear was 0.5 mm/yr. Thin polyethylene liners (less than 6 mm) and titanium heads were used in all failed implants both of which have been abandoned.
Rothman Institute, Pennsylvania Hospital, Philadelphia 19107.
G P
GP
Cautilli
J
J
Beight
B
B
Yao
W J
WJ
Hozack
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D010014:Osteolysis; D011095:Polyethylenes; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D012086:Reoperation; D013314:Stress, Mechanical; D014025:Titanium