We assessed the difference in hospital based and early clinical
outcomes between the direct anterior approach and the posterior
approach in patients who undergo total hip arthroplasty (THA). The outcome was assessed in 448 (203 males, 245 females) consecutive
patients undergoing unilateral primary THA after the implementation
of an ‘Enhanced Recovery’ pathway. In all, 265 patients (mean age:
71 years (49 to 89); 117 males and 148 females) had surgery using
the direct anterior approach (DAA) and 183 patients (mean age: 70
years (26 to 100); 86 males and 97 females) using a posterior approach.
The groups were compared for age, gender, American Society of Anesthesiologists
grade, body mass index, the side of the operation, pre-operative
Oxford Hip Score (OHS) and attendance at ‘Joint school’. Mean follow-up
was 18.1 months (one to 50).Aims
Patients and Methods
Modern metal-on-metal bearings produce less wear debris and osteolysis, but have the potential adverse effect of release of ions. Improved ceramic-on-ceramic bearings have the lowest wear of all, but the corrosion process has not been analysed. Our aim was to measure the serum ion release (ng/ml) in 23 patients having stable hip prostheses with a ceramic-on-ceramic coupling (group A) and to compare it with the release in 42 patients with a metal-on-metal bearing (group B) in the medium term. Reference values were obtained from a population of 47 healthy subjects (group C). The concentrations of chromium, cobalt, aluminium and titanium were measured. There was a significant increase of cobalt, chromium and aluminium levels (p <
0.05) in group B compared with groups A and C. Group A did not differ significantly from the control group. Despite the apparent advantage of a metal-on-metal coupling, especially in younger patients with a long life expectancy, a major concern arises regarding the extent and duration of ion exposure. For this reason, the low corrosion level in a ceramic-on-ceramic coupling could be advantageous.
