D. Hornbach, P. Prevey, Lambda Technologies, Cincinnati, OH; D. McNulty, J. Carr, P. Sade, A. Craft , DePuy Orthopaedics, Inc., Warsaw, IN
Total hip replacement surgery is often required to relieve pain brought on by damage from disease or fracture as well as provide an improved range of motion. Advanced technologies in hip implants have provided stronger, longer lasting devices that meet the ever-increasing demands of more active patients. Modular hip implants are becoming more popular because they allow the surgeon to interoperatively tailor the size of the implant to the patient's individual anatomy.
A customized low plasticity burnishing (LPB) process was developed and applied to
Ti-6Al-4V ELI distal stem tapers, used in a modular hip construct, to provide increased fatigue strength and improved tolerance to fretting damage. The LPB process produced a deep layer of compression while providing a superior surface finish. High cycle fatigue results obtained on LPB treated stems are compared to untreated stems. Residual stresses produced by the LPB process were characterized via x-ray diffraction methods on the treated taper region of the stems. Residual stress results are shown for both LPB treated and untreated parts.
Fatigue strength of Ti-6Al-4V ELI distal stems used in modular hip constructs was improved using Low Plasticity Burnishing (LPB). The taper region of the distal stem was treated with LPB providing a deep layer of compressive residual stress with superior surface finish. LPB eliminated fatigue initiation from fretting damage. High cycle fatigue results and residual stress data are shown.
