Repetitive reduction lead to significant elevated IL-6 and decreased IL-10 levels in femoral osteotomies: A quantitative analysis of a robot-assisted reduction process in a rat model.
BACKGROUND
The field of robot-assisted fracture reduction has been developed by several research groups over more than one decade by now, with the main goals of increasing the fracture reduction accuracy. However, the influence of different reduction paths to patients' physiology is not fully known yet. The aim of our study was to compare the impacts of a robot-assisted direct reduction path versus an artificially prolonged reduction path by measuring the cytokine responses in an in vivo rat model.


METHODS
Thirty-six male CD(©) rats were assigned into three groups with an external fixator and osteotomy on the left femur. Seven days later, the robot was attached and one group was reduced in a single attempt, while the other group underwent 10 attempts by the robot. The third group was the control group without reduction. Before, and as well as 6, 24 and 48h after the reduction process blood samples were collected. IL-1, IL-6, IL-10, IL-17, and MCP-1 concentrations where analysed via ELISA or cytometric bead assay. Muscle biopsies in the osteotomy area were collected 48h after the reduction process for histological analyses. Statistical significance was set at p≤0.05.


RESULTS
Analysis of the cytokines showed that the pro-inflammatory cytokine IL-6 of the Ten-Attempts reduction group significantly increased 6h after reduction compared to the control group. IL-6 further showed markedly elevated levels 6h after surgery in the Ten-Attempts reduction group compared to the Single-Attempt reduction group. On the anti-inflammatory side, IL-10 showed a significant decrease in the Ten-Attempts reduction group 6h after reduction compared to the Single-Attempt reduction and control group. Muscle biopsies showed a significant increase of pathological changes in both reduction groups and an increase in the severity of bleedings of the Ten-Attempts reduction group compared to the Single-Attempt reduction and control group.


CONCLUSIONS
A direct and gentle reduction procedure as feasible by the aid of a robot is preferable over a prolonged reduction in terms of cytokine response and tissue changes.
Hannover Medical School (MHH) - Trauma Department, Hannover, Germany. Electronic address: Neunaber.Claudia@mh-hannover.de.
Claudia
C
Neunaber
Hannover Medical School (MHH) - Trauma Department, Hannover, Germany.
Hannes
H
Wypior
Technische Universität Braunschweig, Institute for Robotics and Process Control, Braunschweig, Germany.
Ralf
R
Westphal
Hannover Medical School (MHH) - Trauma Department, Hannover, Germany.
Maximilian
M
Petri
General Hospital Braunschweig, Department of Trauma and Orthopaedic Surgery, Braunschweig, Germany.
Thomas
T
Goesling
Department of Orthopaedics and Trauma Surgery, University Hospital Aachen, Aachen, Germany.
Frank
F
Hildebrand
Hannover Medical School (MHH) - Trauma Department, Hannover, Germany.
Christian
C
Krettek
Hannover Medical School (MHH) - Trauma Department, Hannover, Germany.
Philipp
P
Haas
D000818:Animals; D005264:Femoral Fractures / Q000378:metabolism / Q000601:surgery*; D005269:Femur / Q000378:metabolism*; D016753:Interleukin-10 / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism*; D008297:Male; D023421:Models, Animal; D000070799:Open Fracture Reduction; D010027:Osteotomy; D051381:Rats; D065287:Robotic Surgical Procedures
D015850:Interleukin-6; D016753:Interleukin-10
Computer-assisted surgery; Femoral fracture; Interleukin 10; Interleukin 6; Surgical robot