Summary

Simultaneous bilateral unicompartimental knee arthroplasty provides excellent midterm results with low risk of complications in adecuated selected patients. It represents a reliable and definitive option in the treatment of the bilateral knee osteoarthritis.

Abstract

Objective

Bilateral unicompartmental knee arthroplasty (bUKA) can benefit from a single hospital admission and rehabilitation time. The purpose of this article is to examine the functional results, complications and survivorship at midterm of bilateral single-stage unicompartmental knee arthroplasty in the treatment of bilateral knee osteoarthritis.

Material And Methods

Retrospective report. We selected and analysed all patients who received a bUKA for treatment of bilateral knee osteoarthritis between January 2004 and January 2020, with a minimun follow-up of 1 year. The KSS score system 2011 and serial radiographs were used in the evaluation of each patient. The transfusion requirements, duration of hospital stay, incidence of complications of the bUKA were evaluated. The prothesis survivorship was assessed.

Results

We identified 86 bUKA in 43 patients with a follow-up of 6.1 years (1.1-17). The clinical and functional KSS improve from 46.1 ± 10.2 to 80.9 ± 15.9 and 22.8 ± 11.9 to 89.8 ± 18.9 respectively (p<0.005). Postoperative maximal flexion improves from 106º ± 5.2º to 125.1º ± 4.2º and flexion contracture improves from 7.5º ± 2.2º to 2.3º ± 1.6º (p<0.005). The duration of hospital stay was 39.8 hours, and 2 patients required transfusion (4.7%). Three knees (3.5%) required revision surgery for aseptic loosening after 7, 8.6 and 12 years. The survivorship rate was 96.5%.

Conclusion

Simultaneous bilateral unicompartmental knee arthroplasty provides excellent midterm results with low risk of complications in adecuated selected patients. It represents a reliable and definitive option in the treatment of the bilateral knee osteoarthritis.