Aims. The aims of this study were to evaluate wear on the surface of cobalt-chromium (CoCr) femoral components used in total knee arthroplasty (TKA) and compare the wear of these components with that of
Fracture of a
We analysed 54 alumina ceramic-on-ceramic bearings
from total hip replacements retrieved at one centre after a mean
duration of 3.5 years (0.2 to 10.6) in situ. These
implants were obtained from 54 patients (16 men and 38 women) with
a mean age of 67 years (33 to 88) who underwent revision for a variety
of reasons. Posterior edge loading was found in the majority of
these retrievals (32 out of 54). Anterosuperior edge loading occurred
less often but produced a higher rate of wear. Stripe wear on the
femoral heads had a median volumetric wear rate of 0.2 mm. 3. /year
(0 to 7.2). The wear volume on the femoral heads corresponded to
the width of edge wear on the matching liner. Anteversion of the
acetabular component was found to be a more important determinant
than inclination for wear in
Aims Osteolysis from polythene debris contributes to loosening of total hip components. Will
Purpose:
Introduction: Ceramics appear to be good material for bearing surfaces due to their extreme hardness. We present the follow up results on 726 Total Hip Replacements using ceramics done in an institution over 19 years. Patients and methods: This is a single surgeon series of 836 total hip replacements using
Aims. Metal and
The leading indication for revision total hip
arthroplasty (THA) remains aseptic loosening owing to wear. The younger,
more active patients currently undergoing THA present unprecedented
demands on the bearings. Ceramic-on-ceramic (CoC) bearings have
consistently shown the lowest rates of wear. The recent advances,
especially involving alumina/zirconia composite
Aims. The survival of humeral hemiarthroplasties in patients with relatively intact glenoid cartilage could theoretically be extended by minimizing the associated postoperative glenoid erosion.
A standard is defined as something established by authority, custom, or general consent. Clearly that does not exist for
Hydroxyapatite
At ten years, alumina
The use of hard-on-hard bearings, including ceramics peaked in the mid 2000's and has seen rapid decline since that time. Ceramics are not new to the market place but have had a 40 year history outside the U.S. The basis for renewed enthusiasm for ceramics included improved manufacturing, improved taper tolerances, higher strength, and lower wear. In spite of the major improvements concerns have been expressed with new generation ceramics by the experts and thought leaders in the field. The major concerns included complications related to modularity, continued problems with fracture and consequences of fracture, limited surgical options, and squeaking and impingement. The conclusion of one review article was that “although ceramics show promise as a lower wear articulation, manufacturing and design modifications and improvements will continue in an attempt to address the substantial concerns that persist”. Modifications have indeed occurred. The question is rather all of these concerns have been addressed and the answer is no. One proposed solution was a hybrid material of Alumina and Zirconia (Delta Ceramic). The advantages included higher strength, lower wear, more options and possibly less squeaking. Unfortunately the modest material improvements did not begin to overcome the obstacles to adopting this technology. High on this list is the problem with cost with the current health care environment unwilling to pay for expensive new technology that does not have proven value. A 2nd major issue is new technology must account for variability in surgeon performance in maximising margin for error. The medical legal environment is unforgiving of failure of new unproven options. Most of the old issues with ceramics have not been completely resolved. Delta
Current CoC hip bearing ranges are typically from 28mm to 36mm diameter, but to improve stability and range of motion, a novel large diameter hip bearing is introduced, with bearing diameter from 32mm to 48mm. To minimise acetabular bone loss, a low profile acetabular component is required and achieved with a
A
The purpose of this study is to analyze clinical and radiological results of total hip arthroplasty using the 3rd generation
Squeaking in
Ceramic bearing fracture is a rare complication following implantation using modern day ceramic bearing materials. Revision bearing options in such cases is debated, with the choice between ceramic-on-ceramic and ceramic-on-polyethylene bearings. Revision to a hard on soft bearing raises concerns about potential catastrophic wear secondary to a third-body reaction caused by the fractured
A major challenge for total hip arthroplasty is to minimize wear and osteolysis in young, active patients. Alumina