Modification of ESIN-osteosynthesis in a Femoral Fracture Model and Its Transmission to Clinical Practice (ESIN)

Modification of ESIN-osteosynthesis in a Femoral Fracture Model and Its Transmission to Clinical Practice

From Bench to Bedside: Modification of Elastic Stable Intramedullary Nailing With a 3rd Nail in a Femoral Spiral Fracture Model and Its Transmission to Clinical Practice

Elastic stable intramedullary nailing (ESIN) is the standard treatment for displaced diaphyseal femoral fractures in children. However, some literature report high complication rates (10-50%) in complex fractures. Data of our own patients with special emphasis on complications showed also mediocre results. Thus, a biomechanical study was conducted to search for modifications. In this study the stiffness with a 3rd nail implanted was compared to the classical 2 C-shaped configuration. For each of the 3 configurations of retrograde ESIN (titanium nails) eight composite femoral grafts (Sawbones®) with an identical spiral fracture were used: 2C configuration (2 C-shaped nails, 2x3.5 mm), 3CM configuration (3rd from antero-medial, + 1x2.5 mm) and 3CL configuration (3rd from antero-lateral, + 1x2.5 mm). Each group underwent biomechanical testing in 4-point bending, IRO/ERO and axial compression (0°/9°). Due to a significantly higher stiffness of 3CL in the anterior-posterior, internal rotation and 9° compression directions implantation of 3 nails became standard treatment for all dislocated femoral fractures at our department. All patients were followed prospectively. The following data was collected: Type of osteosynthesis, any kind of complication (additional procedures like cast or external fixateur, Re-Do operations, misalignment, pseudarthrosis, skin irritation, infection), time until full weight bearing and time until implant removal. At follow-up the legs were controlled for a possible length discrepancy and a possible deviation of axis. Patients' satisfaction was controlled by CSQ (clients satisfaction score, Larsen et al 2002). Further on the Harris Hip Score was used. X-ray controls were done as standard care protocol after 1 and 3-4 months (dependend on age). Level of Evidence IV Keywords: Elastic stable intramedullary nailing, biomechanical testing, fracture, femur, treatment, children, adolescents.

Elastic stable intramedullary nailing, biomechanical testing, fracture, femur, treatment, children, adolescents

Prospectively all patients treated with the 3-nail-configuration for dislocated femoral shaft fractures were enrolled; 25 patients are planned, 18 could be enrolled Comparison will be with own previous data of patients treated with the "classical" 2-C-shaped ESIN-osteosynthesis

Follow up X-rays will be measured for misalignment in degrees (sagittal, frontal and transverse plane) Data will be grouped as a) 1 - 5° b) 6 - 10° c) 11 - 15° d)16 - 20° e) 20 - 30° f) > 30°

both legs will be measured from spina iliaca anterior superior to the lateral malleolus in cm. Results will be grouped as: a) 0 - 0.5 cm b) 0.6 - 1.0 cm c) 1.1 - 1.5 cm d) 1.6 - 2.0 cm e)> 2 cm

Inclusion Criteria: Dislocated femoral fracture ESIN osteosynthesis Exclusion Criteria: No given informed consent Other osteosynthesis than ESIN

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Kaiser MM, Zachert G, Wendlandt R, Rapp M, Eggert R, Stratmann C, Wessel LM, Schulz AP, Kienast BJ. Biomechanical analysis of a synthetic femoral spiral fracture model: Do end caps improve retrograde flexible intramedullary nail fixation? J Orthop Surg Res. 2011 Sep 18;6:46. doi: 10.1186/1749-799X-6-46.

Kaiser MM, Wessel LM, Zachert G, Stratmann C, Eggert R, Gros N, Schulze-Hessing M, Kienast B, Rapp M. Biomechanical analysis of a synthetic femur spiral fracture model: Influence of different materials on the stiffness in flexible intramedullary nailing. Clin Biomech (Bristol, Avon). 2011 Jul;26(6):592-7. doi: 10.1016/j.clinbiomech.2011.01.012. Epub 2011 Feb 22.

Kaiser MM, Stratmann C, Zachert G, Schulze-Hessing M, Gros N, Eggert R, Rapp M. Modification of elastic stable intramedullary nailing with a 3rd nail in a femoral spiral fracture model - results of biomechanical testing and a prospective clinical study. BMC Musculoskelet Disord. 2014 Jan 8;15:3. doi: 10.1186/1471-2474-15-3.