No abstract

Background: Achilles tendon ruptures are characterized by a long recovery period, high re-rupture rate and late return to work. To overcome these difficulties and augment tendon repair, many agents have been used. Aims: To determine the effect of autologous platelet rich plasma (PRP) in the treatment of Achilles tendon ruptures in rabbits. Study Design: Animal experimentation. Methods: The study included 14 New Zealand albino rabbits that were divided randomly into 2 groups, A and B, each containing seven rabbits. On day zero, all 28 Achilles tendons were tenotomized and repaired. In group A, the tendons were injected with PRP post-surgery, whereas those in group B were left untreated. On day 28, the right tendons in both groups were examined histopathologically via both light and electron microscopy, and the left tendons were subjected to biomechanical testing. Results:The histological and biomechanical findings in both light and electron microscopy in group A were better than those in group B, but the difference was not significant. According to Tang's scale, the mean value in Group A was 3.57, while it was 3.0 in Group B. The mean value of Group A for the length of collagen bands was 48.09 nm while the mean value of Group B was 46.58 nm (p=0.406). In biomechanical tests, although stiffness values were higher in group A, the difference between groups was not significant. In addition, maximum load values did not differ between groups A and B. Conclusion: PRP had no effect on the healing process 28 days post-Achilles tendon rupture.

Amaç: Bu çalışmada minimal invaziv perkütan endoskopik diskektomi sonrası omurganın hareketli segmentinin biyomekanik değişiklikleri sağlam omurga ile karşılaştırıldı ve endoskopik diskektominin lomber kuzu omurgası üzerindeki etkileri araştırıldı. Gereç ve yöntemler: Bu çalışmada 10 adet taze donmuş kuzu omurgası kullanıldı. Her bir omurgaya L4-L5 seviyesinde perkütan endoskopik diskektomi yapıldı. Sağlam ve endoskopik diskektomi yapılmış omurgalar için biyomekanik test, aksiyel kompresyon test makinesi kullanılarak gerçekleştiril-di. Aksiyel kompresyon tüm örneklere 5 mm/dk yükleme hızı ile uygulandı. Her bir omurgaya, özel tasarlanmış bir aparatla, 8400 N/mm moment fleksiyon, ekstansiyon, sağa eğilme ve sola eğilme hareketlerinde uygulandı. Bulgular: Aksiyel kompresyon ve fleksiyon testlerinde yer değiştirme bulgularına göre örnekler daha stabildi. Diskektomi yapılmış omurgaların yer değiştirme değerleri, sağlam omurgaların değerlerine yakındı. Her iki grup karşı-laştırıldığında, sadece sola eğilme ön-arka kayma değerleri anlamlı idi (p≤0.05). Sonuç: Perkütan transforaminal endoskopik diskektominin, (PTED) biyomekanik ve klinik açıdan dezavantajı yoktur. Endoskopik diskektominin stabilite yönünden de herhangi bir dezavantajı yoktur. Yalnızca sola eğilmede öne arkaya kayma değerleri istatistiksel olarak anlamlı bulundu. Bu sonuçların nedenini tüm omurgaların sol taraftan PTED yapılmış olmasına bağlamaktayız.Anahtar sözcükler: Biyomekanik; endoskopik diskektomi; sağlam omurga.Objectives: This study aims to perform a biomechanical comparison of changes on motion segments after minimally invasive percutaneous endoscopically discectomized and intact spine and to investigate the effects of endoscopic discectomy on the lumbar spine of the lamb. Materials and methods: Ten fresh-frozen lamb spines were used in this study. Percutaneous endoscopic discectomy was performed on each spine at L4-L5 level. The biomechanical tests for both intact spine and endoscopically discectomized spine were performed by using axial compression testing machine. The axial compression was applied to all specimens with a loading speed of 5 mm/min. 8400 N/mm moment was applied to each specimen to achieve flexion and extension motions, right and left bending through a specially designed fixture. Results: In axial compression and flexion tests, the specimens were more stable based on displacement values. The displacement values of discected spines were closer to the values of intact specimens. Comparing both groups, only displacement values of the left-bending anteroposterior test were significant (p≤0.05). Conclusion: Percutaneous transforaminal endoscopic discectomy (PTED) has no biomechanical and clinical disadvantages. Endoscopic discectomy has also no stability disadvantages. Only anteroposterior displacement values of left bending test were statistically significant. We consider that the reason for such results were due to the fact that PTED was performed on the left side of all specimens.

Objectives: Purpose of current study was biomechanical comparison of changes wrought on motion segments after minimally invasive percutan endoscopic discectomized and intact spine. Materials and Methods: We prepared ten fresh-frozen lamb spines were used for this study. The spine of each specimen was dissected between L4-L5. The biomechanical tests for both intact spine and discectomized spine were performed by using axial compression testing machine (AG-I 10 kN, Shimadzu, Japanese). The axial compression was applied to all specimens with the loading speed of 5 mm/min. 8400 N/mm moment was applied to each specimen to achieve flexion and extension motions, right and left bending by a specially designed fixture. Results: In axial compression and flexion tests, the specimens were more stable according to displacement values. The displacement values of sectioned specimens were closer to intact specimens. Only displacement values of left-bending anteroposterior test for both situations were significant (0.05 ≥ P). Conclusion: PTED hasn't biomechanical and cilinical disadvantages. Endoscopic discectomy hadn't any disadvantages in stability. Only anterior-posterior displacement values of left bending test were statistically significant. We consider that cause of these results were due to the fact that all specimens had percutan transforaminal endoscopic discectomy (PTED) from left side.

The use of a three-parallel screw construct seems to provide more stability in the treatment of tongue-type IIC fractures.