Mehmet KOCAOĞLU, Levent ERALP, Kerem BILSER, Ergün BOZDAĞ, Emin SÜNBÜLOĞLU

Eksternal fiksasyonda stoplu K-teli ile birlikte cerrahi pul kullanımının kemik yüzey kinetikleri üzerine etkisi: Biyomekanik çalışma

Amaç: Eksternal fiksasyonda K-tellerinin tipi ve konfigürasyonunun fiksasyon stabilitesi üzerinde önemli etkisi vardır. Osteoporotik hastalardaki çeşitli kas-iskelet patolojilerinin tedavisinde eksternal fiksatör uygulama endikasyonları artmıştır. Bu biyomekanik çalışmada, stoplu K-teli ile birlikte cerrahi pul kullanımının kortikal kemik arasındaki yüzey kinetiği üzerine etkisi incelendi. Çalışma planı: Çalışmada, bir yaşındaki koyunlardan çıkartılmış 32 adet tibia kemiği kullanıldı. Tibiaların proksimal kısımlarından sekizerli dört grup halinde deney piyesleri oluşturuldu. Tibiaların proksimal metafizer bölgelerine 1.8 mm’lik stoplu (olive) K-telleri gönderildi. Kontrol grubu dışındaki gruplarda stoplu K-teli ile birlikte sırasıyla 5 mm, 7 mm, 10 mm çaplarında cerrahi pul kullanıldı. Örneklere, özel tasarım ile imal edilmiş servo-hidrolik üniversal test makinesinde, kırılma noktasına kadar 10 mm/dk ile statik çekme kuvveti uygulandı. Sonuçlar: Ortalama kırılma kuvveti kontrol grubunda 806.9 N bulunurken, stoplu K-teli ile birlikte 5 mm, 7 mm, 10 mm çapında cerrahi pul kullanılan gruplarda sırasıyla 1285.9 N, 1317.9 N ve 1345.9 N bulundu. İstatistiksel karşılaştırmada, kontrol grubu ile diğer üç grup arasındaki fark anlamlı iken (p

Anahtar Kelimeler:

Osteoporoz, Donanım tasarımı, Biyomekanik, Kemik telleri, Kırık tespiti, Koyun

The effect of surgical washers used with olive K-wires on bone surface kinetics in external fixation: a biomechanical study

Objectives: In external fixation, the type and configuration of K-wires have a considerable effect on fixation stability. Indications for external fixation have recently increased in the treatment of various musculoskeletal pathologies in osteoporotic patients. This biomechanical study was designed to determine the effect of surgical washers used with olive wires on surface kinetics of the cortical bone. Methods: The study included 32 tibiae obtained from oneyear- old sheep. Samples were prepared from the proximal parts of the tibiae which were then divided into four groups equal in number. A 1.8-mm olive K-wire was inserted into the proximal metaphyseal regions of the tibiae. Except for the control group, surgical washers were used with olive K-wires in the three study groups, with diameters of 5 mm, 7 mm, and 10 mm, respectively. The samples were then placed in a specially designed servo-hydraulic universal testing machine for static tensile test at 10 mm/min. Results: The mean failure load was 806.9 N in the control group, compared to 1285.9 N, 1317.9 N, and 1345.9 N in the three groups in which 5-mm, 7-mm, and 10-mm surgical washers were used, respectively. While there were significant differences between the control and study groups (p<0.0001), failure loads did not differ significantly between the three study groups (p=0.574). Conclusion: The use of surgical washers in combination with olive K-wires offers a significant advantage to increase stability and to decrease surface pressure. We recommend utilization of washers for external fixation surgery in osteoporotic patients and osteoporotic bone segments.

Keywords:

Osteoporosis, Equipment Design, Biomechanics, Bone Wires, Fracture Fixation, Sheep,

PDF

___

1. Paley D, Fleming B, Catagni M, Kristiansen T, Pope M. Mechanical evaluation of external fixators used in limb lengthening. Clin Orthop Relat Res 1990;(250):50-7.
2. Paley D. Operative principles of Ilizarov. In: Bianchi- Maiocchi A, Aronson J, editors. Biomechanics of the Ilizarov external fixator. Baltimore: Williams & Wilkins; 1991. p. 33-42.
3. Voor MJ, Antoci V, Antoci V Jr, Roberts CS. The effect of wire plane tilt and olive wires on proximal tibia fracture fragment stability and fracture site motion. J Biomech 2005;38:537-41.
4. Kocaoglu M, Sar C, Kılıcoglu O, Asık M, Cakmak M. Predeformation loading capacity of various stopper types of Kirschner wires. [Article in Turkish] Acta Orthop Traumatol Turc 1996;30: 179-82.
5. Kummer FJ. Biomechanics of the Ilizarov external fixator. Bull Hosp Jt Dis Orthop Inst 1989;49:140-7.
6. Bianchi-Maiocchi A. Instruments and their use. In: Bianchi- Maiocchi A, Aronson J, editors. Operative principles of Ilizarov. Baltimore: Williams & Wilkins; 1991. p. 9-32.
7. An YH, Burgoyne CR, Crum MS, Glaser JA. Current methods and trends in fixation of osteoporotic bone. In: An YH, editor. Internal fixation in osteoporotic bone. New York: Thieme Medical Publishers; 2002. p. 73-108.
8. Goslings JC. External fixation in osteoporotic bone. In: An YH, editor. Internal fixation in osteoporotic bone. New York: Thieme Medical Publishers; 2002. p. 186-93.
9. Chao EY, Aro HT, Lewallen DG, Kelly PJ. The effect of rigidity on fracture healing in external fixation. Clin Orthop Relat Res 1989;(241):24-35.
10. Aronson J, Harrison B, Boyd CM, Cannon DJ, Lubansky HJ. Mechanical induction of osteogenesis: the importance of pin rigidity. J Pediatr Orthop 1988;8:396-401.
11. Ilizarov GA. The apparatus: components and biomechanical principles of application. In: Transosseous osteosynthesis. Theoretical and clinical aspects of the regeneration and growth of tissue. Berlin: Springer-Verlag, 1992. p. 63-136.
12. Antoci V, Roberts CS, Antoci V Jr, Voor MJ. The effect of transfixion wire number and spacing between two levels of fixation on the stiffness of proximal tibial external fixation. J Orthop Trauma 2005;19:180-6.
13. Roberts CS, Antoci V, Antoci V Jr, Voor MJ. The effect of transfixion wire crossing angle on the stiffness of fine wire external fixation: a biomechanical study. Injury 2005;36:1107-12.
14. Fleming B, Paley D, Kristiansen T, Pope M. A biomechanical analysis of the Ilizarov external fixator. Clin Orthop Relat Res 1989;(241):95-105.