Clinical and radiographic outcomes of total hip replacement with a 3-part metaphyseal osseointegrated titanium alloy stem enhanced with low plasticity burnishing: a mean 5-year follow-up study

Abstract

Background: This study evaluates midterm results of a 3-part titanium alloy stem with metaphyseal fixation and a neck-metaphyseal taper junction strengthened with low plasticity burnishing (LPB). Our hypothesis is that this multimodular implant with LPB succeeds in offering the advantages of three-part modularity without junctional failure. Methods: Twenty-eight of 32 complex primary (n = 9) and revision (n = 9) total hip arthroplasties were accounted for with minimum 2-year follow-up. Clinical and radiographic data were reviewed at a mean follow-up period of 60 months. One stem, removed for failure to osseointegrate, was submitted for sectioning and taper examination. Results: There were no modular junction failures despite body mass indices of 20 to 40 and offsets of 34 to 47 mms. Implant survival was 96.3%, with one removal due to aseptic loosening in a patient with chronic renal failure. Taper analyses of the removed implant showed minimal damage. Preoperative and postoperative Harris Hip Scores and Oxford Hip Scores were 20 to 86 and 16 to 41, respectively. Patient satisfaction was 9.7/10. Radiographs showed stem subsidence >2 mm and radiolucencies around the metaphyseal cone only in the hip requiring implant removal. Conclusions: This 3-part titanium alloy modular stem with LPB of the neck-metaphyseal taper junction showed good functional and radiographic results at a mean 5 years without junctional failures. Although this follow-up exceeds previously published reports, longer follow-up will be important to confirm our confidence in the additional strengthening provided by LPB. Keywords: Hip arthroplasty, Osteoarthritis of hip, Modular, Modular junction