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 .
Primary total hip arthroplasty with a cementless porous-coated anatomic total hip prosthesis: 10- to 12-year results of prospective and consecutive series.
We performed a prospect i ve study in 108 consecutive patients ( 116 hips ) who were followed for a minimum of 10 years ( 10 - 12 years ) after primary total hip arthroplasty using an uncemented porous-coated anatomic ( PCA ) hip prosthesis . The average age of the patients at operation was 48.4 years ( range , 19 - 85 years ) , and the diagnosis was avascular necrosis of the femoral head in 46 hips , neglected femoral neck fracture in 27 , osteoarthrosis secondary to childhood pyogenic arthritis in 24 , childhood tuberculous arthritis in 5 , and miscellaneous in 14 . The average preoperative Harris Hip Score was 55 points , which improved to 87 points at 11 years . Seventy-five hips ( 65 % ) were excellent , 11 ( 9 % ) were good , and 30 ( 39 % ) were poor . The overall rate of revision was 15 % ( 17 of 116 hips ) . The rate of revision of the femoral component was 11 % ( 13 of 116 hips ) , and the rate of revision of the acetabular component was 15 % ( 17 of 116 hips ) . The prevalence of thigh pain was 28 % at 11 years . The increase in the incidence of aseptic loosening of the femoral component was found to explain the high incidence of severe thigh pain at 11 years ' follow-up . At 11 years , there was femoral osteolysis in 69 hips ( 59 % ) and acetabular osteolysis in 65 hips ( 56 % ) . At 6 years , 20 hips ( 17 % ) showed definite wear of the polyethylene liner . At 11 years , 81 hips ( 70 % ) showed definite wear of the polyethylene liner . Because the complication rate of the PCA hip prosthesis with respect to loosening , osteolysis , and excessive wear in the polyethylene liner is high , we ab and oned the use of this implant
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 .