Early Experience with a Tapered Titanium Porous Plasma Sprayed Stem with Updated Design.

INTRODUCTION: The Taperloc® Complete femoral stem (Zimmer Biomet, Warsaw, Indiana) builds on the widespread clinical success of the original Taperloc design used since 1982. Enhancements to the Complete design include a lowered caput-collum-diaphyseal (CCD) angle from 138° to 133° for improved offset, optimized neck taper with polished neck flats to increase range of motion, reduced distal geometry to improve proximal canal fill, and gradual off-loading that is the goal of tapered geometry. A retrospective review was conducted to assess our early experience with the updated design.

MATERIALS AND METHODS: A query of our practice's arthroplasty registry revealed 97 consented patients (103 hips) who underwent primary cementless THA performed with a Taperloc® Complete femoral component between November 2010 and March 2011. A high offset option, accomplished by a constant 7.8mm medial shift of the trunnion, was utilized in 94 hips (91%). Mean age was 61.8 years and body mass index (BMI) was 31.3 kg/m2. Underlying diagnoses were osteoarthritis in 96 (93%), four avascular necrosis, two post-traumatic arthritis, and one acute fracture.

RESULTS: Mean follow-up was 5.3 years (2-7). Harris hip scores improved from 53.6 preoperatively to 87.9 at most recent. One stem was revised for periprosthetic fracture. Other reoperations were one cup revised for iliopsoas impingement, one lateral femoral cutaneous neurectomy, and one incision and debridement for a non-healing wound. Postoperative radiographs revealed satisfactory position and alignment of components with no radiolucencies observed in all patients with no evidence of osteolysis, distal hypertrophy, or pedestal formation.

CONCLUSION: In this group, good results with a low frequency of complications and stem revision were achieved with a tapered titanium porous plasma-sprayed femoral component with updated design features. No aseptic loosening or osteolysis occurred. Radiographic findings were excellent in all hips.