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 .
Predictors of patient relevant outcome after total hip replacement for osteoarthritis: a prospective study
Objectives : To investigate prospect ively long term patient relevant outcomes after  unilateral total hip replacement ( THR ) for osteoarthritis ( OA ) . To identify non-responders to this intervention and patient related predictors of unsatisfactory outcome . Methods : A case-control study comparing health related quality of life of 219 patients ( mean age 71 ) after THR with that of a matched reference group of 117 subjects without hip complaints recruited from the community . Patients and reference group answered SF-36 and WOMAC question naires preoperatively , at 3 , 6 , 12 months , and at 3.6 years ( range 26–65 months ) postoperatively . Supplementary questions were asked at the final follow up . Results : 198/211 ( 94 % ) of the patients and 83/109 ( 76 % ) of the reference group participated at the final follow up . At follow up , the only difference between the two groups in the SF-36 was physical function , where patients scored worse . Patients also reported worse WOMAC function . 31 % of the patients had improved by < 10/100 WOMAC score points for pain and /or function at final follow up , compared with preoperatively . More pain preoperatively and higher age and postoperative low back pain predicted a worse outcome in WOMAC function . Conclusion : 3.6 years after THR for OA , health related quality of life was similar for patients and reference group except for function , where patients had worse function . Higher age and more pain preoperatively predicted a poor outcome . Patients with hip OA with musculoskeletal comorbidities , such as low back pain and OA of the non-operated hip , have less long term functional improvement after THR
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 .