The torsional alignment changed significantly in growing rabbits after patella dislocation by a three-dimensional measurement
Abstract Background: Torsional malalignment has been considered as a risk factor for patella dislocation. But the influence of patella dislocation for torsional alignment development remains unknown. The present study aims to investigate whether the torsion alteration of the hindlimb occur after patella dislocation in growing rabbits. Methods: In the present study, 30 one-month old rabbits were included. The experimental group consists of 30 left knees of rabbits and were underwent patella lateral dislocation. And the control group consists of 30 right knees and no surgical procedure was performed. A CT scan was performed on each knee when the surgery was finished and at the time the rabbits were skeletal mature (5 months post-surgery). The angles of femoral version and tibial torsion were measured using a three-dimensional method and analyzed between the experimental group and control group. Results: The femoral version and tibia torsion in the experimental and control group immediately after surgery were not different significantly. However, 5 months after surgery, the femoral version angle of the experimental group (-5.50±6.13°) was significantly different with that of the experimental group (-10.90±4.74°)(P < 0.05). But the tibia torsion angle in the experimental group (7.17±7.25°) and control group (4.47±6.34°) were not significantly different (P = 0.144). Conclusion: From this study, patella dislocation can lead to alteration of femoral version in growing rabbits. This may indicate the early treatment for patella dislocation in children is particularly important to avoid torsional malalignment in the future. These findings may develop pathology and etiology of patella dislocation.