Radiographic Imaging to improve frontal plane weight bearing symmetry and its impact on gait in transtibial bone...

Optimal frontal plane alignment of transtibial bone-anchored prostheses (BAPs) is essential to minimize knee joint loading asymmetries. This study examined whether bilateral whole-leg radiographic imaging could improve static alignment and reduce knee joint loading during gait in 23 unilateral transtibial BAP users with press-fit osseointegration implants with an experimental within subject study design. Static weight-bearing line (WBL) alignment and frontal plane knee moments during gait were assessed before and after the intervention. Pain levels were monitored one week before and one week after the intervention. Radiographic imaging significantly improved static WBL symmetry (p < 0.001). Thereby, it can be said with 90% confidence that asymmetries above 4.2 mm can be improved by alignment adjustments. The magnitude of these changes was significantly associated with changes in prosthetic-side peak knee adduction moment (p < 0.001), although no significant group-level improvement in dynamic knee adduction moment asymmetry was observed. Pain levels remained unchanged (p = 0.773), and 19 of 23 participants preferred the radiograph-based alignment over their original setup. These findings support radiographic imaging as an effective method for detecting and correcting static misalignments in transtibial BAP users, while highlighting the need for complementary dynamic gait evaluation.