Abstract
We report a retrospective study of the major complications following one-stage and two-stage bilateral unicompartmental knee replacements (UKR). Between 1999 and 2008, 911 patients underwent 1150 UKRs through a minimally- invasive approach in our unit. Of these, 159 patients (318 UKRs) had one-stage bilateral UKR and 80 patients (160 UKRs) had two-stage bilateral UKRs. The remainder were unilateral UKRs.
The bilateral UKR groups were comparable in age and ASA grade, but more females were in the two-staged group (p=0.019). Mechanical thromboprophylaxis was used in all cases. Major complications were recorded as death, pulmonary embolus, proximal deep vein thrombosis (DVT) and adverse cardiac events within 30 days of surgery.
No statistical differences between the groups were found regarding operating surgeon, tourniquet time or minor complications (excepting distal DVT). Anaesthetic times were greater for the two-stage group (p= 0.0001). Major complications were significantly more common with one-stage bilateral UKR (13 patients, 8.2%) compared to two-stage bilateral UKR (no patients) (p=0.005). Distal DVT was more frequent in the two-stage group (p=0.036).
This series reports significantly higher risks of major complications are associated with one-stage bilateral UKR when compared to two-stage bilateral UKR. There is no evidence that the addition of chemical thrombo-prophylaxis would change this risk. We advocate caution before undertaking a one-stage bilateral UKR.
The abstracts were prepared by Mr Matt Costa and Mr Ben Ollivere. Correspondence should be addressed to Mr Costa at Clinical Sciences Research Institute, University of Warwick, Clifford Bridge Road, Coventry CV2 2DX, UK.
