Purpose: To investigate the effects of early patellar dislocation on the tibial tubercle location.
Methods: Sixty knees from 30 healthy 1-month-old New Zealand white rabbits were randomly divided into two groups of 30 knees each. Group A (control group) comprised the left knees, which underwent no surgical procedures. Group B comprised the right knees, which underwent patellar dislocation surgery. Computed tomography (flexion 0°) was performed preoperatively and 6 months post-operatively. Measurements included the tibial tuberosity-trochlear groove distance (TT-TG) and tibial tubercle lateralization.
Results: No significant difference in the TT-TG or tibial tubercle lateralization was found between the two groups preoperatively. Six months post-operatively, however, the mean TT-TG in Group A (no patellar dislocation) and Group B (patellar dislocation) was 1.0 ± 0.4 and 3.0 ± 0.7 mm, respectively (p < 0.05). The mean tibial tubercle lateralization also showed a significant difference between Groups A and B at 6 months post-operatively (0.5 ± 0.1 and 0.6 ± 0.0, respectively; p < 0.05).
Conclusions: Early patellar dislocation can lead to tibial tubercle lateralization and an increased TT-TG. Clinically, early intervention for adolescent patients with patellar dislocation will be important.
Level of evidence: Prospective comparative study, Level II.
Keywords: Dislocation; Patella; Rabbit; Tibial tubercle; Tibial tuberosity–trochlear groove distance.