The Clinical Results of Derotational Osteotomy Based on 3D Osteotomy Template for Treatment of Recurrent Patellar Dislocation Combined With Patellofemoral Maltracking

Study Overview
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Brief Summary
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For severe recurrent patellar dislocation with poor patellar maltracking, derotation osteotomy is an effective clinical treatment. However, derotation osteotomy requires very high requirements for the surgeon. It is necessary to determine the osteotomy surface, control the axis and complete internal fixation in three dimensions. The deviation of the osteotomy surface may cause deformities such as postoperative knee valgus, knee hyperextension, or restricted extension. The hypothesis of this study is to design a 3D osteotomy template for derotation osteotomy with the aid of computer-assisted simulated surgery. Compared with traditional osteotomy, it can effectively improve the treatment effect of recurrent patellar dislocation due to poor patellar maltracking. The incidence of postoperative knee valgus shortens the operation time and reduces the number of intraoperative fluoroscopy. This study intends to adopt a randomized controlled study, and the selection criteria are adolescent patients with recurrent patellar dislocation, aged >14 years, with a positive J sign. The experimental group used mimics 20.0 software to reconstruct the three-dimensional model of the patient based on the full-length images of the lower limbs in the weight-bearing position and the CT of the hip, knee and ankle before the operation. The osteotomy template was designed and 3D printing technology was used to make the osteotomy template for intraoperative osteotomy. The control group used traditional de-rotation techniques. The knee joint range of motion, patella stability, residual rate of J-sign, knee valgus angle, femoral anteversion angle, gait analysis, etc. were compared between the two groups after surgery, and the differences between the two surgical techniques were evaluated

Official Title
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The Clinical Results of Derotational Osteotomy Based on 3D Osteotomy Template for Treatment of Recurrent Patellar Dislocation Combined With Patellofemoral Maltracking

Conditions
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Recurrent Patellar Dislocation, Osteotomy, Patellar Maltracking

Intervention / Treatment
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* Procedure: computer-assisted surgery
* Procedure: traditional osteotomy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with recurrent patellar dislocation >14 years old positive preoperative J-sign agree to participate the study Exclusion Criteria: Combined with other ligament injuries of knee joint Skin and soft tissue conditions do not permit surgery

Ages Eligible for Study
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Minimum Age: 14 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Study group<br>3D osteotomy template for derotation osteotomy with the aid of computer-assisted simulated surgery technique | Procedure: computer-assisted surgery<br>* derotation osteotomy with the aid of 3D osteotomy template and computer-assisted simulated surgery<br>|
| Experimental: Control group<br>traditional osteotomy technique | Procedure: traditional osteotomy<br>* traditional osteotomy without the aid of 3D osteotomy template<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lysholm score | A function score to assess the knee function | 1 year postoperatively | 
| quadriceps strength | to assess the postoperative quadriceps strength using Biodex® | 1 year postoperatively |