Tibial component in total knee replacement : the effect of overhang and sizing on outcome

The aim of this study was to find a relationship between tibial overhang, malpositioning and oversizing, and the functional outcome. 188 patients were included in this retrospective study. All patients completed an Oxford knee score questionnaire at mean follow-up of 5 years. Anteroposterior radiographs of the total knee replacements were reviewed for medial and lateral overhang and oversizing. Lateral overhang was seen in 32.9% of patients with a mean Oxford knee score of 24.7. However lateral overhang proved no significant correlation with the functional outcome. Oversizing was seen in 31.9% of patients and, with a mean of 25.6, oversizing did have a correlation with Oxford Knee score. This studs confirms that neither medial or lateral overhang of the tibial component influences functional outcome, independent of the severity of overhang. Oversizing the tibial component however, does show worse functional outcome scores at a 5 year review.