Changes In Femoral Trochlear Morphology Following Surgical Correction Of Recurrent Patellar Dislocation Associated With Femoral Trochlear Dysplasia In Children

Objective: This study was performed to investigate the changes in femoral trochlear morphology following surgical correction of recurrent patellar dislocation associated with femoral trochlear dysplasia in children.Methods: Twenty-three patients(mean age,7.6 years;range,5-11 years)were evaluated.All patients were diagnosed with bilateral recurrent patellar dislocation associated with femoral trochlear dysplasia.The knee that had either been injured by a traumatic event during this visit or that had been dislocating more frequently underwent medial patellar retinaculum plasty(Group S).The contralateral knee,which served as a control,underwent conservative management(Group C).All patients underwent axial computed tomography to assess the trochlear morphologic characteristics preoperatively and at the last follow-up.Results: Preoperatively,the trochlear morphologic characteristics showed no statistically significant differences between Groups S and C(P >0.05).Numerous measurements of the trochlear morphologic characteristics were significantly different between the two groups at the last follow-up.Significant measurements included well-known parameters such as the sulcus angle(Group S,146.27° ± 7.18°;Group C,160.61° ± 9.29°;P < 0.05),trochlear groove depth(Group S,6.25 ± 0.41 mm;Group C,3.48 ± 0.65 mm;P <0.05),and lateral trochlear inclination(Group S,20.99° ± 3.87°;Group C,12.18° ± 1.85°;P < 0.05).Lesser-known measurements such as the ratio of the lateral trochlear to medial trochlear length(Group S,1.46 ± 0.19;Group C,2.14 ± 0.42;P < 0.05),which is a measurement of facet asymmetry,were also found to be significantly different between the two groups.The lateral condylar height and medial condylar height were also significantly differentbetween the two groups(P < 0.05).Conclusions: The femoral trochlear morphology can be improved following early surgical correction of recurrent patellar dislocation associated with femoral trochlear dysplasia in children.