The Novel Application of Three-Dimensional Printing Assisted Patient-Specific Instrument Osteotomy Guide in the Precise Osteotomy of Adult Talipes Equinovarus

Abstract

Objective: This current research is aimed at assessing clinical efficacy and prognosis of three-dimensional (3D) printing assisted patient-specific instrument (PSI) osteotomy guide in precise osteotomy of adult talipes equinovarus (ATE).

Methods: We included a total of 27 patients of ATE malformation (including 12 males and 15 females) from June 2014 to June 2018 in the current research. The patients were divided into the routine group (n = 12) and 3D printing group (n = 15) based on different operative methods. The parameters, including the operative time, intraoperative blood loss, complications, time to obtain bony fusion, functional outcomes based on American Orthopedic Foot and Ankle Society (AOFAS), and International Congenital Clubfoot Study group (ICFSG) scoring systems between the two groups were observed and recorded regularly.

Results: The 3D printing group exhibits superiorities in shorter operative time, less intraoperative blood loss, higher rate of excellent, and good outcomes presented by ICFSG score at last follow-up (P < 0.001, P < 0.001, P = 0.019) than the routine group. However, there was no significant difference exhibited in the AOFAS score at the last follow-up and total rate of complications between the two groups (P = 0.136, P = 0.291).

Conclusion: Operation assisted by 3D printing PSI osteotomy guide for correcting the ATE malformation is novel and feasible, which might be an effective method to polish up the precise osteotomy of ATE malformation and enhance the clinical efficacy.

Figure 1

Design and fabrication processes of the 3D printing models and guides. (a) According to the imported CT data, the deformed structure of the ankle joint was simulated in Mimics19.0 software. (b) 1 : 1 reference model printed based on the simulation result. (c) In order to correct the deformity of arch elevation, the osteotomy planes were defined on the joint surfaces. (d) The simulated osteotomy for correcting the deformity of arch elevation was performed at the defined osteotomy planes, and the reduction was performed after osteotomy (frontal view). (e) The result of reduction after the simulated osteotomy (lateral view). (f) In order to correct the deformity of talipes varus, the osteotomy planes were defined on the joint surfaces. (g) The simulated osteotomy for correcting the deformity of talipes varus was performed at defined osteotomy planes, and the reduction was performed after osteotomy. (h) The osteotomy model and guides fabricated by the 3D printing technique.

Figure 2

Intraoperative photographs of operation assisted by the 3D printing assisted PSI osteotomy guide. (a) The arc-shaped incision was made from the dorsolateral side of the foot to about 2 cm below the lateral malleolus. (b) and (c) The PSI osteotomy guide was fixed with the preset Kirschner wire guide holes on the binding surfaces, and the precise osteotomy was performed under the guidance of guides. (d) The reconstruction plate was used for the shaping and fixation of ATE malformation.

Figure 3

Female, 57 years old, who has suffered from CTE in right side for 50 years. (a) The patient has not paid enough attention to the CTE and walked on the back of foot for 20 years. (b) Preoperative appearance, and the physical examination revealed that the right ankle joint was stiff, the subtalar joint had no range of motion, and the knee tendon reflex was hyperactive. (c) and (d) Preoperative X-ray and 3D reconstruction CT scanning of right ankle joint indicated the severe ATE malformation of the patient.

Figure 4

Postoperative imaging examinations and general appearance of right ankle joint. (a) and (b) Postoperative X-rays indicated that the osteotomy end was well aligned and the fixation effect was reliable. (c) At 12 weeks postoperatively, the osteotomy end obtained the bony fusion confirmed by CT scanning. (d) The general appearance of the right ankle joint at the last follow-up.