[Application of 3D printing guide plate in total hip arthroplasty for developmental dysplasia of the hip].

Objective: To explore the value of 3D-printed navigation template using in total hip arthroplasty(THA)for developmental dysplasia of the hip (DDH).

Methods: Twenty five patients with DDH underwent total hip arthroplasty from February 2016 to May 2018 were analyzed retrospectively, including 4 males and 21 females, aged from 40 to 75 years old. Among them, 5 cases were Crowe typeⅡ, 14 cases were Crowe type Ⅲ and 6 cases were Crowe type Ⅳ. Twelve cases of them underwent THA with the 3D printing navigation plate, another 13 cases underwent the same operation but without the aid of navigation templates. All patients were treated by the same operators. The operating time, intra- and post-operative hemorrhage and Harris Hip Score(HHS) at six months postoperativelywere compared, anteversion angle, abduction angle and the distance from rotation center to the ischial tuberosity connection between ipsilateral and contralateral sides were also compared.

Results: All of the patients were followed up for 12 to 26 months. The operation time, intra- and post-operative hemorrhage and Harris score in the 3D printing group were better than those in the conventional hip replacement group(<0.05). There were no significant differences in anteversion angle, abduction angle and the distance from rotation center to the ischial tuberosity connection between ipsilateral and contralateral sides in 3D printing group (>0.05). The abduction angle and the distance from rotation center to the ischial tuberosity connection were significantly different between the two sides in the traditional group (< 0.05), the abduction angles had no statistical difference (=0.487) between two sides.

Conclusion: The 3D-printed operation navigation template technique is an individualized, accurate and promisingtechnique for THA with DDH.