Wear particles commonly used for experiments may carry adherent endotoxin on their surfaces, which may be responsible for the observed effects. In this study, we attached titanium plates to the tibiae of 20 rats. After osseointegration, endotoxin-contaminated or uncontaminated high-density-polyethylene (HDPE) particles were applied. Contaminated specimens showed a dramatic resorption of bone after seven days but new bone filled the site again at 21 days. Uncontaminated specimens showed no resorption. In 18 rats we implanted intramuscularly discs of ultra-high-molecular-weight
We implanted bone harvest chambers (BHCs) bilaterally in ten mature male New Zealand white rabbits.
It has been suggested that the wear of ultra-high molecular weight
Sterilisation by gamma irradiation in the presence of air causes free radicals generated in
Three normal digital flexor tendon sheaths and the corresponding tissue formed around five silicone rod tendon implants, two silicone rubber mammary prostheses and one
We have prospectively studied the wear of enhanced ultra-high molecular-weight
We report the findings from independent prospective clinical and laboratory-based joint-simulator studies of the performance of ceramic femoral heads of 22.225 mm diameter in cross-linked
We present the results of 62 consecutive acetabular
revisions using impaction bone grafting and a cemented polyethylene
acetabular component in 58 patients (13 men and 45 women) after
a mean follow-up of 27 years (25 to 30). All patients were prospectively
followed. The mean age at revision was 59.2 years (23 to 82). We performed Kaplan–Meier (KM) analysis and also a Competing
Risk (CR) analysis because with long-term follow-up, the presence
of a competing event (i.e. death) prevents the occurrence of the
endpoint of re-revision. A total of 48 patients (52 hips) had died or had been re-revised
at final review in March 2011. None of the deaths were related to
the surgery. The mean Harris hip score of the ten surviving hips
in ten patients was 76 points (45 to 99). The KM survivorship at 25 years for the endpoint ‘re-revision
for any reason’ was 58.0% (95% confidence interval (CI) 38 to 73)
and for ‘re-revision for aseptic loosening’ 72.1% (95% CI 51 to
85). With the CR analysis we calculated the KM analysis overestimates
the failure rate with respectively 74% and 93% for these endpoints.
The current study shows that acetabular impaction bone grafting
revisions provide good clinical results at over 25 years. Cite this article:
We used radiostereometric analysis to compare wear rates between uncemented porous sockets and cemented all-polyethylene sockets in a series of 102 hips randomised for either a Harris-Galante or a Charnley cup. Wear was evaluated in 95 hips at a mean of five years (2 to 7). All hips had a cemented, 22 mm head mono-bloc Charnley stem. The mean annual wear rate was 0.09 mm in the Charnley sockets and 0.10 mm in the Harris-Galante sockets, with no statistically significant differences in wear, migration or rotation. We conclude that, up to five years, the wear characteristics of the modular and porous Harris-Galante socket resemble that of the Charnley socket.
The results of using the Ring uncemented polyethylene-to-metal (UPM) prosthesis in patients with protrusio acetabuli or dysplasia are reported. Fifty-four cases of protrusio were analysed and a modified method of measuring the deformity is described; after operation, remodelling of the medial wall had improved, on average, by 29.6%. For the dysplastic acetabulum the main difficulty is the lack of lateral support for the cup. In order to test the hypothesis that this support improves with an uncemented prosthesis, 38 hips with an average follow-up of 31 months were studied. Lateral support, measured radiographically, showed an average increase of 21%. The remodelling effect may be attributed to the biomechanical design of the prosthesis.