Recently, Zheng Jiang, Director of the Sports Medicine Diagnosis and Treatment Center of Xi'an Honghui Hospital, and Zhang Xian, Deputy Director, led the surgical team member Zhang Mingyu, Associate Chief Physician and Ren Bo, Attending hysician performed the comprehensive patellar dislocation orthopaedic surgery for a patient with habitual patellar dislocation for the first time by 3D printing assistive technology.

The patient, 34 years old, male, developed lateral dislocation of lateral knee patella 20 years ago, but has not been effectively treated for a long time. Three years ago, the frequency of knee dislocation was increased, the lateral dislocation of patella occurred every time when the patient bends its knees, and the knee joint pain gradually appeared and the squat was difficult. Long-term disease affliction has seriously affected his normal life and caused a serious burden on its family. The patient came to Xi'an Honghui Hospital for treatment. Zheng Jiang, Director of the Sports Medicine Center, analyzed the patient's condition in detail. Zhang Xian, Associate Chief Physician, led his surgery team to discuss and diagnose that the patient has severe habitual patellar dislocation, the lower extremity patellofemoral joint rotational deformity and femoral trochlear dysplasia on the basis of the knee joint soft tissue dysequilibrium (Dejour D type is the most serious type of femoral trochlear dysplasia).

The surgical team obtained the femoral and tibia data through accurate 3D CT scanning for the patient, cooperated with the top 3D printing application platform (Shaanxi Xinweitai Biotechnology) in the northwest region to print the patient's proportional femoral shaft and tibia model using 3D printing technology and remodel the developmental deformity of the patient's femoral trochlear. By measuring the patient's lower extremity force line rotation and femoral trochlear dysplasia skeletal deformity by printing model, the team provides the basis for selecting the suitable tibia tubercle osteotomy correction direction and displacement length for operative correction of patella trajectory, designs the accurate osteotomy scope for trochleoplasty and reshapes the patellofemoral joint shape and corrects the patella trajectory for patients with dysplastic femoral trochlear.

Recently, the Deputy Director Zhang Xian led the surgical team to perform a comprehensive orthomorphia for patient with habitual patellar dislocation by using 3D printing technology, and successfully completed the comprehensive orthomorphia of lateral patella release, tibial tubercle osteotomy displacement (Elimslie-Trillat technology), medial patellofemoral ligament reconstruction (MPFLR) and Deepening Trochleoplasty. After surgery, the patient's external dislocated trajectory was corrected; the patient was able to walk and start rehabilitation training. The surgical results are satisfactory.

The application of personalized 3D printing technology to habitual patella dislocation orthopedic surgery has not been reported in China. The comprehensive computer-aided 3D printing technology can provide the surgeon with accurate judgment of the patient's patella dislocation deformity and estimation of preoperative orthopedic plan. This will undoubtedly shorten the operation time, improve the accuracy of osteotomy and make correct preoperative planning for correcting the tibia trajectory.

The successful implementation of this technology marks that the Sports Medicine Diagnosis and Treatment Center of Honghui Hospital can provide digital, accurate and individualized clinical diagnosis and treatment services for patients with such complex and difficult diseases, and can further determine the future development direction of precision sports medicine treatment field.