Radiation-free Three-dimensional Models Based on Three-dimensional Magnetic Resonance Imaging of the Hip Joint for Children with Slipped Capital Femoral Epiphysis

Purpose or Learning Objective: Slipped capital femoral epiphyses is a common pediatric hip disease with the risk of osteoarthritis and impingement deformities, and three-dimensional models could be useful for patient-specific analysis. Therefore, we investigated magnetic resonance imaging bone segmentation.

Methods or Background: A retrospective study approved by the institutional review board involving 23 symptomatic pediatric patients (23 hips) with slipped capital femoral epiphyses was performed. All patients underwent preoperative hip magnetic resonance imaging with pelvic axial high-resolution images (T1 volumetric interpolated breath-hold Dixon images). Slice thickness was 1.2 mm. Mean age was 12 ± 2 years. All patients underwent surgical treatment. Manual and automatic bone segmentation based on magnetic resonance imaging was compared. Automatic bone segmentation was performed by a machine learning algorithm, a previously used and validated convolutional neural network trained for adult pelvis bone segmentation adapted to the pelvis of children.

Results or Findings: Manual bone segmentation based on magnetic resonance imaging was feasible (all patients, 100%; duration 4–5 hours per case). The Dice coefficient was calculated to assess differences between manual and automatic bone segmentation. It was 82% for the pelvis and 88% for the proximal femur. Precision was 80% for the pelvis and 94% for the proximal femur.

Conclusion: Three-dimensional models based on magnetic resonance imaging were feasible for patients with slipped capital femoral epiphyses. Three-dimensional models could be useful for patients with slipped capital femoral epiphyses for preoperative three-dimensional printing and deformity analysis. This method could aid patient-specific diagnosis, treatment decisions, and preoperative planning. The three-dimensional models based on magnetic resonance imaging are radiation-free and could be used in the future instead of three-dimensional models based on computed tomography models for simulation of surgery.

Publication History

Article published online:
02 June 2025