The intra-articular administration of tranexamic acid (TXA) has
been shown to be effective in reducing blood loss in unicompartmental
knee arthroplasty and anterior cruciate reconstruction. The effects
on human articular cartilage, however, remains unknown. Our aim,
in this study, was to investigate any detrimental effect of TXA
on chondrocytes, and to establish if there was a safe dose for its
use in clinical practice. The hypothesis was that TXA would cause
a dose-dependent damage to human articular cartilage. The cellular morphology, adhesion, metabolic activity, and viability
of human chondrocytes when increasing the concentration (0 mg/ml
to 40 mg/ml) and length of exposure to TXA (0 to 12 hours) were
analyzed in a 2D model. This was then repeated, excluding cellular
adhesion, in a 3D model and confirmed in viable samples of articular cartilage.Aims
Materials and Methods
Polyethylene wear debris can cause osteolysis
and the failure of total hip arthroplasty. We present the five-year
wear rates of a highly cross-linked polyethylene (X3) bearing surface
when used in conjunction with a 36 mm ceramic femoral head. This was a prospective study of a cohort of 100 THAs in 93 patients.
Pain and activity scores were measured pre- and post-operatively.
Femoral head penetration was measured at two months, one year, two
years and at five years using validated edge-detecting software
(PolyWare Auto). At a mean of 5.08 years (3.93 to 6.01), 85 hips in 78 patients
were available for study. The mean age of these patients was 59.08
years (42 to 73, the mean age of males (n = 34) was 59.15 years,
and females (n = 44) was 59.02 years). All patients had significant
improvement in their functional scores (p <
0.001). The steady
state two-dimensional linear wear rate was 0.109 mm/year. The steady
state volumetric wear rate was 29.61 mm3/year. No significant
correlation was found between rate of wear and age (p = 0.34), acetabular
component size (p = 0.12) or clinical score (p = 0.74). Our study shows low steady state wear rates at five years in
X3 highly cross-linked polyethylene in conjunction with a 36 mm
ceramic femoral head. The linear wear rate was almost identical
to the osteolysis threshold of 0.1 mm/year recommended in the literature. Cite this article:
We carried out a prospective investigation into
the radiological outcomes of uncemented Oxford medial compartment
unicondylar replacement in 220 consecutive patients (231 knees)
performed in a single centre with a minimum two-year follow-up.
The functional outcomes using the mean Oxford knee score and the
mean high-activity arthroplasty score were significantly improved
over the pre-operative scores (p <
0.001). There were 196 patients
with a two-year radiological examination performed under fluoroscopic
guidance, aiming to provide images acceptable for analysis of the
bone–implant interface. Of the six tibial zones examined on each
knee on the anteroposterior radiograph, only three had a partial
radiolucent line. All were in the medial aspect of the tibial base plate
(zone 1) and all measured <
1 mm. All of these patients were
asymptomatic. There were no radiolucent lines seen around the femoral
component or on the lateral view. There was one revision for loosening
at one year due to initial inadequate seating of the tibial component.
These results confirm that the early uncemented Oxford medial unicompartmental
compartmental knee replacements were reliable and the incidence
of radiolucent lines was significantly decreased compared with the
reported results of cemented versions of this implant. These independent
results confirm those of the designing centre.