Data are limited regarding large ceramic femoral heads with highly cross-linked polyethylene. We hypothesized that large ceramic head articulation with highly cross-linked polyethylene is safe with a low wear rate, comparable to metal-on-highly cross-linked polyethylene.
The study group comprised 63 patients (72 hips) who had undergone total hip replacement (THR) with ceramic-on-highly cross-linked polyethylene between April 2006 and March 2007 with a minimum 2-year follow-up. Postoperative Western Ontario and Mc-Master Universities Arthritis Index (WOMAC) and Hospital for Special Surgery (HSS) scores were used for clinical assessment. Six-week and 2-year radiographs were analyzed by 2 independent observers using Roman 1.70 software. Twenty-six patients (29 hips) had 32-mm and 37 patients (43 hips) had 36-mm Biolox delta ceramic femoral heads (Ceramtec, Plochingen, Germany). Mean patient age was 60.9±8.9 years, and mean follow-up was 2.9±0.5 years. Mean postoperative WOMAC and HSS hip scores were 30.4 and 36.6, respectively. Mean wear at 1 and 2 years postoperatively was 0.06±0.28 and 0.006±0.12 mm/yr for all hips, respectively. Mean wear at 1 and 2 years postoperatively for the 32-mm femoral head was 0.063±0.278 and 0.007±0.126 mm/yr, respectively, and for the 36-mm femoral head was 0.057±0.292 and 0.006±0.118 mm/yr, respectively. No patient had any clinical complications, such as reoperation, infection, fractures, or radiographic evidence of osteolysis or loosening. The early results of THR with large ceramic heads demonstrate high safety and efficacy. Our data with 2-year follow-up show low wear rates, similar to published data for metal-on-highly cross-linked polyethylene.
Drs Meftah, Ebrahimpour, Ranawat (Amar), and Ranawat (Chitranjan) are from Weill Medical College of Cornell University, Hospital for Special Surgery, New York, New York; and Dr He is from Ruijin Hospital, Shanghai Jiao Tong University Medical School, Shanghai, China.
Drs Meftah, Ebrahimpour, He, Ranawat (Amar), and Ranawat (Chitranjan) have no relevant financial relationships to disclose. Wear and osteolysis are major contributors to limiting the durability of total hip replacement and ultimately leading to failure. 1,2 Efforts to decrease polyethylene wear debris have included cross-linking of polyethylene and the use of alternate bearing surfaces, including ceramic-on-highly cross-linked polyethylene or ceramic-on-ceramic bearings. 3,4 Ceramic bearing surfaces have historically had low wear properties. 4–7 Only a handful of studies have investigated in vivo wear rates of ceramic-on-polyethylene THRs, 3–7 and to our knowledge, none have analyzed wear rates of large ceramic heads on highly cross-linked polyethylene.
The primary goal of our study was to measure the radiographic wear rate of large-diameter alumina matrix composite ceramic femoral heads (Biolox delta; Ceramtec, Plochingen, Germany) on third-generation highly cross-linked polyethylene (Trident X3; Stryker, Mahwah, New Jersey) and to assess its clinical safety and efficacy at minimum 2-year follow-up.
Between April 2006 and March 2007, all patients who had undergone noncemented THR using 32- or 36-mm ceramic femoral heads and highly cross-linked polyethylene liners were identified from a prospective database. Indications for use of a ceramic femoral head were young (aged 55 years or younger) and/or active patients. Exclusion criteria were any major complications such as dislocations, fractures, infections, or any revision or reoperation. Sixty-three patients (72 hips) were included in the study (26 men, 37 women). The majority of the patients were younger than 55 years; however, age was a rough guideline, and patient activity, physiologic age, and choice of implant were also considered. Twenty-nine hips (26 patients) had received a 32-mm femoral head and 43 hips (37 patients) received a 36-mm femoral head. The cup sizes were 50 mm, 54 mm, 65 mm, 58 mm, or 62 mm, and the polyethylene thickness was 5.9 mm, 7.9 mm, 9.4 mm, or 11.2 mm (Table ). All surgeries were performed by 2 surgeons (C.S.R., A.S.R.)