Comparison of two dimensional kinematic analysis of hind limbduring trotting on treadmill in chihuahuas with normal and medial patellar luxation stifles after surgical correction

Abstract

The two dimensional kinematic motion analysis was carried out to characterize active range of motion (AROM), maximal extension angle (MEA) and maximal flexion angle (MFA) of stifle joint, hip joint and tarsal joints on sagittal plane in dogs during trotting on treadmill (velocity 1.11 m/s). Seven healthy Chihuahuas (n=14 normal stifles) and 10 Chihuahuas with grade III medial patellar luxation (MPL) undergoing surgical correction (n=10 MPL stifles) were studied. The parameters were comparing between normal group and MPL group undergone surgical correction at pre-operatively, 2, 4, 6 and 8 weeks post-operatively. The AROM, MEA and MFA of stifle joint in MPL group were significantly lower than normal group (p<0.001). The AROM of tarsal and hip joints in MPL group were significantly higher than in normal group (p<0.001). The surgical correction to realign the quadriceps mechanism was performed with the combined techniques of tibial tuberosity transposition, trochlear block recession, medial desmotomy and lateral imbrication. The AROM of hip joint, stifle and tarsal joints were not significant difference between MPL group and normal group at 8 week post-operatively (p>0.05). In conclusion, the MPL dog lost the performance of stifle extension. The stifle was more flexion and the degree of motion of the hip joint and tarsal joints were increased to compensate the trotting. Moreover, the AROM of hind limb joints could return to normal function at 8 week postoperatively.