The BIRMINGHAM HIP◊ Resurfacing is a metal-on-metal (MOM) hip implant system approved by the US FDA in 2006. The approval required a multicenter, prospective, post-approval study (PAS). Our purpose is to report the current minimum 10-year results. 253 patients (280 hips) had surgery between October 2006 and December 2009 at one of 5 sites. We report revisions, survivorship, EQ-5D, Harris Hip Score (HHS), radiographic findings, and metal levels including cobalt (Co) and chromium (Cr). The mean age at surgery was 51 years, 74% male, BMI 28, osteoarthritis 95%. 243 (87%) of hips have known outcome or 10-year minimum follow-up (fup). Prior to 10 years, 5 patients died, 20 hips were revised, and 37 hips did not complete 10-year fup.Introduction
Methods
We report the five- to-ten year results of Anderson Orthopaedic Research Institute type-2 bone defects treated with modular metal augments in revision knee surgery. A total of 102 revision knee arthroplasties in patients with type-2 defects treated with augments and stems were prospectively studied. Seven patients (seven knees) had incomplete follow-up and 15 patients (16 knees) died with the arthroplasty We recommend the use of modular augmentation devices to treat type-2 defects in revision knee surgery.
We report on five-ten year results of AORI type two bone defects treated with modular augments in revision knee surgery. 102 revision knee arthroplasties with type two defects were treated with augments &
stems and minimum five-year follow-up were prospectively studied. 15 patients (16 knees) died with retention of their prosthesis, 7 knees had incomplete follow-up. There were 79 remaining knees with complete follow-up of 7+−2 years (range: 5 – 11). The presence of non-progressive radiolucent lines around the augment in 20% of knees was not associated with poorer knee scores, range of motion, component survival or type of insert used (p>
0.05). Kaplan-Meier survival of the components was 92+− 0.03% at 11 years (95%CI:10.3–11.2) We support the use of modular augmentation devices to treat type 2 defects in revision knee surgery and conclude that theoretical concerns of fretting and loosening based on 5 – 10 year clinical data are unfounded.
