Related Experiment Video
Updated: Oct 5, 2025

Four-Dimensional CT Analysis Using Sequential 3D-3D Registration
Published on: November 23, 2019
Morphologic Analysis of Nonosseous Talocalcaneal Coalitions Using 3D Reconstruction
Azusa Yoneda1, Yasuhito Tanaka1, Hiromasa Fujii1
1Department of Orthopaedic Surgery, Nara Medical University, Nara, Japan.
Background:
Resection of talocalcaneal coalitions has generally involved osseous coalitions. We attempted to evaluate the morphology of nonosseous talocalcaneal coalitions. This study aimed to investigate if the calcaneal articular surface area of feet with talocalcaneal coalitions is different than that of normal feet.
Methods:
Twenty nonosseous talocalcaneal coalition cases with analyzable computed tomography (CT) scans were compared to 20 control cases. Three-dimensional models of the talus and calcaneus were constructed, and the surface areas of the posterior facet (SPF), whole talocalcaneal joint of the calcaneus (SWJ), and coalition site (SCS) of each 3D-CT model were measured. "Calibrated" values of the 2 groups were created to adjust for relative size of the tali and then compared. The preoperative and postoperative AOFAS Ankle-Hindfoot scale was calculated for 9 cases that had undergone single coalition resection.
Results:
The calibrated SPF and SWJ were significantly greater in the coalition group than in the control group (40% and 12%, respectively). No significant difference was detected between the calibrated (SWJ - SCS) value of the coalition group and the calibrated SWJ value of the control group. The AOFAS scale was improved postoperatively in all 9 cases analyzed.
Conclusion:
The calcaneal articular surface of nonosseous talocalcaneal coalition feet in our series was larger than that of the normal feet. This study indicates that the total calcaneal articular surface after coalition resection may be comparable to the calcaneal articular surface of normal feet. We suggest that the indication for coalition resection be reconsidered for nonosseous coalition.
Level Of Evidence:
Level III, retrospective comparative study.
Related Concept Videos
Classification of Bones
Long and Short Bones
The appendicular skeleton, particularly the upper and lower limbs, is primarily made of long and short bones. The...
Bone Remodeling
Ankle Joint
Bones of the Lower Limb: Tibia and Fibula
Bone Structure
Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into ...

