Abstract:
Background and Objectives: Despite the established role of subtalar joint arthrodesis (SJA) for treatment of subtalar osteoarthritis, achieving bone union remains challenging, with up to 46% non-union rates. Adequate compression and stable fixation are crucial for successful outcomes, with internal screw fixation being the gold standard for SJA. The delta configuration, featuring highly divergent screws, offers stability, however, it can result in hardware irritation in 20-30% of patients. Solutions to solve this complication include cannulated compression screw (CCS) countersinking or cannulated compression headless screw (CCHS) application. The aim of this biomechanical study was to investigate the stability of a delta configuration for SJA utilizing either a combination of a posterior CCHS and an anterior CCS or a standard two-CCS combination. Materials and Methods: Twelve paired human cadaveric lower legs were assigned pairwise to two groups for SJA using either two CCSs (Group 1) or one posterior CCHS and one anterior CCS (Group 2). All specimens were tested under progressively increasing cyclic loading to failure, with monitoring of the talocalcaneal movements via motion tracking. Results: Initial stiffness did not differ significantly between the groups, p = 0.949. Talocalcaneal movements in terms of varus-valgus deformation and internal-external rotation were significantly bigger in Group 1 versus Group 2, p ≤ 0.026. Number of cycles until reaching 5° varus-valgus deformation was significantly higher in Group 2 versus Group 1, p = 0.029. Conclusions: A delta-configuration SJA utilizing a posterior CCHS and an anterior CCS is biomechanically superior versus a standard configuration with two CCSs. Clinically, the use of a posterior CCHS could prevent protrusion of the hardware in the heel, while an anterior CCS could facilitate less surgical time and thus less complication rates.
摘要:
背景和目的:尽管距下关节固定术(SJA)在治疗距下骨关节炎中的作用已确立,实现骨结合仍然具有挑战性,高达46%的非工会率。足够的压迫和稳定的固定对于成功的结果至关重要。螺钉内固定是SJA的黄金标准。delta配置,具有高度发散的螺钉,提供稳定性,然而,它会导致硬件刺激20-30%的患者。解决这种复杂性的解决方案包括空心压缩螺钉(CCS)埋头孔或空心压缩无头螺钉(CCHS)应用。这项生物力学研究的目的是利用后CCHS和前CCS的组合或标准的两CCS组合来研究SJA的三角洲构型的稳定性。材料和方法:使用两个CCS(第1组)或一个后CCHS和一个前CCS(第2组),将十二对人类尸体小腿成对分为两组进行SJA。所有试样在逐渐增加的循环载荷下进行破坏测试,通过运动跟踪来监测距骨运动。结果:两组之间的初始刚度没有显着差异,p=0.949。与第2组相比,第1组的内翻-外翻变形和内外旋转方面的颅骨运动明显更大,p≤0.026。直到达到5°内翻-外翻变形的循环次数在第2组中明显高于第1组,p=0.029。结论:使用后CCHS和前CCS的三角洲构型SJA在生物力学上优于具有两个CCS的标准配置。临床上,使用后部CCHS可以防止鞋跟中的硬件突出,而前路CCS可以缩短手术时间,从而降低并发症发生率。