Delta Ceramic-on-Alumina Ceramic Articulation in Primary THA: Prospective, Randomized FDA-IDE Study and Retrieval Analysis

Abstract

Wear and osteolysis continue to be major reasons for revision surgery in THA. Ceramic-on-ceramic bearings eliminate polyethylene wear debris. The newest generation of these bearings incorporate nanosized, yttriastabilized tetragonal zirconia particles producing an alumina matrix composite. We asked whether this new material would perform as well as a conventional bearing in terms of functional hip scores, radiographic migration and osteolysis, complications and survival. As part of a US FDA investigational device exemption study (G000075), we conducted an initial prospective safety study of 21 alumina matrix composite femoral heads articulating on alumina liners followed by a prospective, randomized study with 44 more of these articulations and 45 zirconia femoral heads on polyethylene liners. The minimum followup for all patients was 26 months (mean, 73 months; range, 26-108 months). Harris hip scores and radiographic findings were similar in the two groups as was survivorship (trial 95% versus control 93%). There were three reoperations in the trial group and three in the control group. A fractured head retrieval showed a 33% monoclinic transformation with an increase in surface roughness from 3 to 5 nm at the main wear zone. While our numbers were insufficient to compare device-related complications, the trial device performed as well as the control device in terms of reoperation, and clinical and radiographic outcome. The alumina matrix composite femoral head on an alumina liner provided high survivorship.

Causes of Failure of Ceramic-on-Ceramic and Metal-on-Metal Hip Arthroplasties

“…During the past decade, various studies have reported outcomes and survival of alternative bearing surfaces in THA [6,7,9,12,14,15,19,20,[23][24][25]. Complications associated with the use of hard-on-hard bearings include squeaking, fracture, liner disassociation, metallosis, and hypersensitivity reactions occurring in some patients [14].…”

Does Acetabular Inclination Angle Affect Survivorship of Alumina-ceramic Articulations?

“…Recently, improvements in manufacturing processes have produced ceramics with smaller grain sizes, lower porosity, and higher density, leading to stronger and more fractureresistant materials [29]. This may lead to component fracture rates as low as one in 25,000 in some reports [35]; however, it remains to be determined whether these design modifications will actually decrease fracture rates [24]. Because the incidence of fracture may have been reduced, the current thought is that the primary cause of failure in ceramic-on-ceramic bearings is now due to increased wear rates related to component malpositioning [31,32].…”

Comparative Effectiveness of Ceramic-on-Ceramic Implants in Stemmed Hip Replacement

“…Several studies with various follow-up durations have compared C-C bearings with C-P bearings 15,[32][33][34][35][36][37] ; most had both baseline and postoperative measurements. In addition, one trial compared C-C with M-P bearings; this had only postoperative measurements [11][12][13][14] .…”