Hip Arthroplasty with a Collared Straight Cobalt-chrome Femoral Stem Using Second-generation Cementing Technique: a 10-year-average Follow-up Study

Clinical and radiographic results of 116 patients who had undergone 132 hip arthroplasties at our institution from 1983 to 1988 with a collared cemented straight cobalt-chrome femoral stem using second-generation cementing technique were reviewed. Twenty hips in 20 patients who were part of the original cohort were lost to follow-up. Mean age at the time of surgery was 68.2 years. Mean radiographic follow-up was 9.6 years with a minimum follow-up of 5 years. Ten-year survivorship of the component was 96.5% with revision considered as an endpoint and 94.2% with either revision or radiographic loosening considered the endpoint. Three implants (2.3%) were revised for aseptic loosening at a mean of 8.1 years after implantation. One implant (0.8%) was revised for septic loosening at 10.5 years after surgery. Of the implants not revised, 1 showed evidence of circumferential bone-cement radiolucencies, and 1 had radiolucencies at the implant-cement interface. Five of the surviving femoral components (5.0%) showed focal areas of cystic osteolysis, and proximal femoral bone resorption under the collar was seen in 32 patients (31.7%). There were no cases of cement fracture or stem subsidence. The biomechanical and material properties of this stem combined with second-generation cementing technique look promising for long-term survivorship.