[Revision possibilities after failed unicompartmental knee arthroplasty--an analysis of 116 revisions]

A major advantage of the unicompartmental knee arthroplasty (UKA) is the quick rehabilitation, small traumatisation of tissue and the mostly uncomplicated revision to a total knee arthroplasty. The aim of the study is to examine whether the conversion to the total endoprosthesis, as is frequently is recommended at present in cases of defect of the sleigh system, is always necessary or whether a revision can have good chances of success with use of the unicondylar system under certain conditions.

116 revisions were studied after unicompartmental knee arthroplasty at the first appearance of problems and during the follow-up of 45 months (range: 10-86 months) using the Knee Society Score and analyses of the various additional procedures as well as the anterior cruciate ligament substitute, the correction of slope etc. Revisions, with exchange of components or a conversion to a total arthroplasty, were included.

In 60.3 % of all cases a revision could be performed within the unicompartmental knee system, with a mean score of 167.4 (range: 144-173). The outcome score corresponded to the outcome of primary UKA implantations and to conversion operations to total endoprosthesis in the literature (p < 0.05 Wilcoxon test).

Under critical contemplation of the low case number and this short- to medium-term examination, individual revision solutions seem to have their entitlement within the unicondylar system as also do conversion operations to the TKA. Long-term results and larger case numbers are absolutely necessary prior to further judgment.