Plastic, Reconstructive and Burns Surgery Department, University Hospital La Paz , Madrid , Spain
Orthopaedic and Trauma Department, General Hospital of Villalba , Collado Villalba , Spain
Orthopaedic and Trauma Department, Hospital Universitario Gregorio Marañón , Madrid , Spain
Orthopaedic and Trauma Department, Ramón y Cajal University Hospital , Madrid , Spain
Orthopaedic and Trauma Department, University Research Institute in Musculoskeletal Diseases, School of Medicine, Catholic University of Valencia , Valencia , Spain
Surgery Department, School of Medicine, Complutense University of Madrid , Madrid , Spain
Orthopaedic and Trauma Department, Hospital Universitario Gregorio Marañón , Madrid , Spain
Orthopedic and Trauma Department, La Fraternidad Hospital , Madrid , Spain
Department of Orthopedics and Traumatology, Vito Fazzi Hospital , Lecce , Italy
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Department of Orthopedics and Traumatology, Vito Fazzi Hospital , Lecce , Italy
Division of Orthopedics and Trauma Surgery, University of Perugia, S. Maria della Misericordia Hospital , Perugia , Italy
Division of Orthopedics and Trauma Surgery, University of Perugia, S. Maria della Misericordia Hospital , Perugia , Italy
Aim
To validate surgical costotransversectomy as a technique for creating a scoliosis model in minipigs and to assess whether differences in approach (posterior medial approach, posterior paramedial approach and anterior approach by video-assisted thoracoscopy) lead to differences in the production of spinal deformity. Creation of disease models in experimental animals, specifically in minipigs, is controversial, as no appropriate technique has been reported.
Methods
Surgical costotransversectomy was performed in 11 minipigs using 3 different approaches: posterior medial approach (4 animals, group I), posterior paramedial approach (3 animals, group II) and anterior approach by videothoracoscopy (4 animals, group III). A conventional x-ray study was performed in the immediate postoperative period. Follow-up lasted for 4 months. Specimens were humanely killed according to current protocols, and a second x-ray study was performed. A deformation was measured using the Cobb angle and direct observation of the rotational component.
Results
Data from group I revealed a scoliosis deformation of 27º-41º (mean 34.5º) with a macroscopic rotational component. No deformity (<10º) or rotational component was observed in groups II and III. Only a posterior medial costotransversectomy produced a significant deformity in minipigs and established a valid model for studying scoliosis in these animals.
Conclusion
Only a posterior medial costotransversectomy produces a significant deformity in minipigs and establish a valid model for studying scoliosis in these animals. A tensegrity model would elucidate such results and harmonize disparate conclusions. Further investigation is needed to demonstrate the reliability of tensegrity principles for spinal biomechanics.
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