In a series of 1000 medial OUKA followed up to 15 years, we assessed the postoperative activity level using the Tegner Score (Kozinn & Scott, 1989). Patients with higher levels of activity, not surprisingly, had higher OKS (Ali et al. 2015). However, contrary to accepted wisdom, there was a significant reduction in revision rate associated with increased activity (Fig. 5.6). In general, impact activity is not recommended after joint replacement. This level of activity would be 5 or more on the Tegner scale (5 being ‘jogging on uneven ground’ or ‘heavy labour’). We found that the 115 patients with a Tegner score of five or more had an OKS of 45 and 12-year survival of 97.3%, whereas the 885 with Tegner 4 or less had OKS of 39.9 and 12-year survival of 94.0%. It is not clear why the survival improves with increased activity. It may be that the bone and cartilage are stronger in more active patients so failures due to loosening or disease progression are less likely to occur. Also with the mobile bearing, failure due to wear should not occur. Whatever the reason it is clear that, after OUKA, activity should be encouraged not discouraged. Furthermore, provided the patients have significant symptoms, high levels of activity or expectations of achieving high levels of activity should not be considered to be a contraindication to OUKA.
