Browsing by Subject "Arthroplasty, Replacement, Hip"

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    High Survivorship With a Titanium-encased Alumina Ceramic Bearing for Total Hip Arthroplasty
    (Springer US, 2014-02) D’Antonio, James A.; Capello, William N.; Naughton, Marybeth; Department of Orthopaedic Surgery, IU School of Medicine
    Background Although ceramic-on-ceramic bearings for total hip arthroplasty (THA) show promising results in terms of bearing-surface wear, fracture of the bearing, insertional chips, and squeaking remain a concern. Questions/purposes Our primary objective of this report was to determine overall survivorship of a titanium- encased ceramic-on-ceramic bearing couple. Our secondary objectives were to evaluate for ceramic fracture, insertional chips, osteolysis, and device squeaking. Methods Six surgeons at six institutions implanted 194 patients (209 hips) with an average age of 52 years with cementless hips and alumina ceramic bearings. One hun- dred thirty-seven patients (146 hips) have 10-year followup (70%). We determined Kaplan-Meier survivorship of the bearing surface and implant system and collected radio- graphic and clinical data to evaluate for osteolysis and squeaking. Results Survivorship using revision for any reason as the end point was 97% at 10 years and survivorship end point bearing surface failure or aseptic loosening of 99%. There was one ceramic insert fracture (0.5%), there were no insertional chips, there was no visible osteolysis on AP and lateral radiographs, and there was a 1% patient- self-reported incidence of squeaking at the last clinical followup. Six hips underwent revision (3.7%). Conclusions Ceramic bearings for THA with a titanium- encased insert have high survivorship at 10 years followup and a fracture risk of 0.5%. We found at last followup on routine radiographs no evidence of osteolysis, and no patient has been revised for squeaking or has reported dissatisfaction with the clinical result because of noise. Level of Evidence Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
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    Periprosthetic Fractures Around a Cementless Hydroxyapatite-coated Implant: A New Fracture Pattern Is Described
    (Springer US, 2014-02) Capello, William N.; D’Antonio, James A.; Naughton, Marybeth; Department of Orthopaedic Surgery, IU School of Medicine
    Background Periprosthetic fractures can occur both intraoperatively and postoperatively with implantation of cementless tapered stems. Questions/purposes In a large cohort of patients receiving cementless, proximally hydroxyapatite-coated femoral implants, we answered the following questions: What was the incidence of intraoperative and postoperative fractures associated with the implant? What were the fracture patterns as classified by the Vancouver classification system? Did the Vancouver classification represent the fracture patterns found? How were the fractures treated and what were the treatment outcomes; that is, how many fractures healed and did the stems osseointegrate? Methods We evaluated 1039 hips (932 patients) from three prospective studies. The hips were divided into three groups: no fractures, intraoperative fractures, and postoperative fractures. Demographic differences among the groups were noted. Postoperative fractures were classified using the Vancouver classification system. We judged stem stability using Engh’s criteria and fracture union was determined by the treating surgeon and confirmed by the authors. Results We identified 58 periprosthetic fractures in the 1039 hips (5.6%): 38 intraoperative (3.7%) and 20 postoperative (1.9%). Eleven of the postoperative fractures were classifiable by the original Vancouver classification system and nine were of the newly described “clamshell” variety, not classifiable by this system. No intraoperative fractures extended below the lesser trochanter. Twenty-five of these fractures were treated with a single cable or cerclage wire. The remaining received no specific treatment. Of the 20 postoperative fractures, five were treated nonoperatively. All stems osseointegrated. Conclusions Both intraoperative and postoperative fractures can be managed with success when the stem is stabilized or found to be osseointegrated. An adjustment to the Vancouver classification is suggested to include the clamshell fracture, which has not been previously described. Level of Evidence Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.