Lateral unicompartmental knee replacements: early results from a District General Hospital

Lateral unicompartment knee replacements are performed infrequently in the United Kingdom. This study evaluates the experience of two knee surgeons in a District General Hospital for all lateral unicompartmental arthroplasties performed between October 2007 and August 2011. Two different implants were used in this time period, the Oxford domed and the Zimmer fixed-bearing system. Twenty-seven procedures were completed in this time span (15 Oxford domed and 12 Zimmer fixed bearing), all of which once completed were followed up and 21 patients completed an Oxford knee score. Average Oxford knee scores were 36.6 (95 % CI 29.0-44.2) for the Oxford domed prosthesis and 28.6 (19.8-37.5) for the Zimmer fixed-bearing prosthesis (p = 0.15). One patient with an Oxford domed prosthesis required revision for bearing dislocation. The follow-up Oxford knee scores support the use of this technique as an alternative to total knee replacement but with no significant difference in functional outcome. Our results, however, may encourage a more cautious approach to the use of a mobile-bearing prosthesis in favour of a fixed-bearing prosthesis.