The alignment alteration of transverse plane in growing rabbits after patella dislocation
Abstract Background: Torsional malalignment in transverse plan has been regarded 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 : Thirty rabbits that were 1 months old were included in the study. The left knees of each rabbit (N = 30 knees/group), were underwent patella lateral dislocation operation and defined as the experimental group. The right knees of each rabbit, defined as the control group (N =30 knees/group), did not undergo any surgical procedures. Computed tomography was performed on each knee immediately post-surgery and 5 months post-surgery to measure femoral version and tibial torsion. The angles was analyzed between the experimental group and control group. Results : The femoral version and tibia torsion in the experimental and control group were not significantly different immediately after surgery. However, 5 months after surgery, the femoral version 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 angle in the experimental group (7.17±7.25°) and control group (4.47±6.34°) were not significantly different ( P = 0.144). Conclusion : Patella dislocation can lead to significant change in femoral version in growing rabbits. Thus if adolescents suffer from patella dislocation or instability for a long time in growing period, the torsional malalignment in lower limbs may occur.