Conclusions Revisions and reoperations are more frequent and occur earlier with metal-on-metal hip resurfacing , except when discontinued devices are removed from the analyses .
Background Metal-on-metal hip resurfacing was developed for younger , active patients as an alternative to THA , but it remains controversial .
Study heterogeneity , inconsistent outcome definitions , and unst and ardized outcome measures challenge our ability to compare arthroplasty outcomes studies .
Questions / purpose sWe asked how early revisions or reoperations ( within 5 years of surgery ) and overall revisions , adverse events , and postoperative component malalignment compare among studies of metal-on-metal hip resurfacing with THA  among patients with hip osteoarthritis .
Secondarily , we compared the revision frequency identified in the systematic review with revisions reported in four major joint replacement registries .
Resurfacing hip prostheses revisited: failure analysis during a 16-year follow-up.
We conducted a prospect i ve study of the clinical and radiographic variables related to the survival of 114 cementless resurfacing double-cup hip replacements ( RHR ) with a mean follow-up of 9 ( range : 1 - -16 ) years . Three patients died , and 22 were unavailable for the final review in 2003 . Sixty-one RHRs had to be revised to a total hip replacement . Failure analysis of these revised RHRs showed femoral head and neck resorption under the prosthesis in 33 , acetabular protrusion in seven , both femoral and acetabular resorption in 14 and a femoral-neck fracture in three . One hip had dislocated , and there were three hips with unexplained pain . The Kaplan-Meier 5-year mean survival was 92 % , the 10-year survival was 47 % ( 95 % CI 37 - -57 % ) and the 15-year survival was 30 % ( 95 % CI 20 - -40 % ) . Pre-operative joint destruction ( grade 1 ) , a high degree of radiological osteoporosis , a body mass index > 25 and prosthesis mismatch were significantly related to failure of the RHR . We believe that in young , non-obese patients with pre-operative radiological central destruction but without severe proximal femoral osteoporosis , a resurfacing arthroplasty may have some value . Our failures were mainly due to femoral resorption under the prosthetic femoral component
Conclusions Revisions and reoperations are more frequent and occur earlier with metal-on-metal hip resurfacing , except when discontinued devices are removed from the analyses .
Background Metal-on-metal hip resurfacing was developed for younger , active patients as an alternative to THA , but it remains controversial .
Study heterogeneity , inconsistent outcome definitions , and unst and ardized outcome measures challenge our ability to compare arthroplasty outcomes studies .
Questions / purpose sWe asked how early revisions or reoperations ( within 5 years of surgery ) and overall revisions , adverse events , and postoperative component malalignment compare among studies of metal-on-metal hip resurfacing with THA  among patients with hip osteoarthritis .
Secondarily , we compared the revision frequency identified in the systematic review with revisions reported in four major joint replacement registries .