Tibial component overhang following unicompartmental knee replacement: Does it matter?

R. Chau, A. Gulati, H. Pandit, D. J. Beard, A. J. Price, C. A. Dodd, H. S. Gill, D. W. Murray

Research output: Contribution to journalArticlepeer-review

122 Citations (SciVal)


As implants are made in incremental sizes and usually do not fit perfectly, surgeons have to decide if it is preferable to over or undersize the components. This is particularly important for unicompartmental knee replacement (UKR) tibial components, as overhang may cause irritation of soft tissues and pain, whereas underhang may cause loosening. One hundred and sixty Oxford UKRs were categorised according to whether they had minor (or=3 mm, 9%) tibial overhang, or tibial underhang (21%). One year post surgery, there was no significant difference in outcome between the groups. Five years after surgery, those with major overhang had significantly worse Oxford Knee Scores (OKS) (p=0.001) and pain scores (p=0.001) than the others. The difference in scores was substantial (OKS=10 points). There was no difference between the 'minor overhang' and the 'underhang' group. We conclude that surgeons must avoid tibial component overhang of 3 mm or more, as this severely compromises the outcome. Although this study showed no difference between minor overhang or underhang, we would advise against significant underhang because of the theoretical risk of component subsidence and loosening.
Original languageEnglish
Pages (from-to)310-313
Number of pages4
JournalThe Knee
Issue number5
Publication statusPublished - 2009


Dive into the research topics of 'Tibial component overhang following unicompartmental knee replacement: Does it matter?'. Together they form a unique fingerprint.

Cite this