Background

The inclusion of bone graft materials during HTO has been shown to positively impact on clinical outcome criteria such as complication rates, delayed union, and correction loss. Graft materials also result in a biomechanically superior construct compared to HTO without grafting but it is unknown whether this affects physical activity levels. The purpose of this study was to investigate the difference that allograft bone grafting has on the post-operative activity levels of HTO patients.

Methods

56 patients (38 males; mean age 50.6 ± 8.8 years; mean BMI 28.8 ± 4.5 kg/m2), who underwent HTO either with an allograft wedge (n=27) or without grafting (n=29), participated in this retrospective study. Pre-operative and post-operative Tegner, UCLA, and KOOS scores were used to estimate physical activity levels and knee function. Data were analysed to detect pre- to post-operative significant differences within and between groups (p<0.05).

Results

Both groups achieved a significant pre- to post-operative improvement in KOOS scores with no difference detected between groups (allograft group: 53.7 ± 15.2 pre-op to 75.2 ± 16.3 post-op; control group: 53.5 ± 17.6 pre-op to 68.5 ± 20.7 post-op). The allograft group achieved the minimum clinically important difference for each of the six KOOS subscales, whereas this was only true for four of the subscales in the control group. A significant improvement in physical activity scores was observed in the allograft group (Tegner: 2.7 ± 1.6 pre-op to 4.2 ± 1.7 post-op; UCLA: 4.7 ± 2.1 pre-op to 6.8 ± 1.8 post-op) but not in the control group (Tegner: 3.3 ± 1.6 pre-op to 3.4 ± 1.8 post-op; UCLA: 5.7 ± 2.5 pre-op to 6.0 ± 2.0 post-op).

Conclusion

HTO with allograft wedges resulted in a larger pre- to post-operative increase in physical activity levels than HTO without graft augmentation. Both operative techniques resulted in similar improvements in reported knee function. However, HTO with allograft wedges was preferable to no grafting due to more consistent and clinically important improvements in post-operative KOOS scores. The use of allograft wedges during HTO is recommended; especially for physically active patients or those with a desire to become more active after surgery.