Unicompartmental knee arthroplasty questionnaire (UniQ-study): Unknown is unloved

Almost 50% of the patients requiring knee replacement are suitable for medial unicompartmental knee arthroplasty (UKA). However, national registries have shown a use far below 50%.

The aim of this study was to identify the factors that could influence the use of UKA.

A questionnaire was conducted among practicing knee surgeons of the Dutch Orthopedic Association. The questionnaire was classified into three domains: surgeon, patient selection, and professional opinion. Associations between the domains and UKA volume and contra-indications were tested using Pearson's chi-square tests.

Of the 113 included respondents, 40% had no hands-on exposure during residency. Frequently reported contra-indications were obesity (68%), lateral osteophytes (21%), chondrocalcinosis (20%), and age (20%). Medial partial thickness lesions were considered a contra-indication by 49% and lateral joint space narrowing by 61% of the respondents. Respondents perceived UKA to outperform total knee arthroplasty regarding all outcomes, except survival (1.8% versus 42%). The reported barriers for UKA use were insufficient experience (20%), high revision rates (20%), and low hospital volume (16%), whereas 60% did not experience any at all. Hands-on UKA exposure during residency was associated with an increased use of correct indications. Furthermore, the use of correct indications was associated with an increased UKA volume.

We showed a low UKA exposure during residency and considerable variations in contra-indications. These factors may contribute to an underuse of UKA. Improved UKA training could lead to increased experience and better patient selection among surgeons and consequently a higher use of medial UKA.