FINAL PAPERA BIOMECHANICAL TEST OF UNILATERAL EXTERNAL FIXATION FRAME AND MODIFIED BILATERAL EXTERNAL FIXATION FRAME USING TIBIAL FRACTURE MODEL OF JAVA GOAT (Capra aegagrushircus)(EXPERIMENTAL STUDY) David Haryadi
BACKGROUND External fixation of tibial bone can be used as a definitive treatment in managing open fracture of tibia which can give a stability and easy wound care. Retrospective study by Jeffry A (2010) between January 2007- September 2010 in Dr. Soetomo Hospital Surabaya, there were 58 cases open fracture cruris grade I, and 113 cases grade II, 89 cases grade III a, 32 cases Grade III b, and 23 cases grade III c. Unilateral frame external fixation have a weakness on its rigidity and classic bilateral frame there is possibility of screw sliding in the bone. Rigidity and biomechanical aspect of implant is one of the important factor for healing process.
Anderson’s early concept called for application of through-and-through transfixion pins. This permitted multiplanar adjustment of the fracture fragments and also allowed compression at the fracture site. After reduction, a cast was applied while the limb was still held by the external device (Roger Anderson). Source: Pontarelli W. External fixaxion of tibia fracture. Department of Orthopaedic Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa. The Iowa Orthopaedic Journal. 1982
Study Purpose This research is an experimental laboratory study with post test only controlled group design. Methode Using 24 samples of Java goat’s tibial bone divided into control group and intervension group which is based on compression, torsion, and bending force Watch for shift the bone over 50% in diameter of compression force, and 10 degree of bending, also every rotation of torsion. Sample Using Federer formula: (t-1) (r-1) ≥ 15, (6 -1) (r-1) ≥ 15, r ≥ 4, minimal 4 sample each (4 x 6) = 24 Sample
(source: Hopkins CE, Hamm TE, Leppart GL; Atlas Of Goat Anatomy. Part I: Osteology. Departement of The Army Edgewood Arsenal. Maryland: September. 1970)
Prototype Material : Stainless Steel 316L (Low carbon) Weight: Schanz screw: 9 gr Connector : 9 gr Modified Pin : 16 gr Rod : 23 gr Weight : Total unilateral Frame (6 SS, 6C, 1R) = 131 gr Total Modified Bilateral Frame (4P, 8C, 2R, 4N) = 182 gr