Associate Professor, Division of Foot and Ankle Surgery, Kent State University College of Podiatric Medicine, Independence, OH.
Professor and Director of Research, Kent State University College of Podiatric Medicine, Independence, OH.
J Foot Ankle Surg. 2021 Mar-Apr;60(2):333-338. doi: 10.1053/j.jfas.2020.05.020. Epub 2020 Nov 18.
The modified Lapidus bunionectomy is a useful and highly powerful procedure for correcting hallux abducto valgus. Traditionally reserved for "severe" deformities, this procedure has seen a recent resurgence in the podiatric community for its unique ability to achieve tri-planar correction of this challenging deformity. Although this procedure has been extensively studied in both biomechanical labs and the clinical arenas, no clear consensus has been achieved regarding optimal fixation for this thought-provoking procedure. The current study examined the differences in strength between commercially available 5-hole locking plates with interfragmentary compression vs a crossed-screw with a third "transfixation" screw construct in a controlled setting. Ten fresh-frozen cadaveric match pair limbs (20 total limbs) were used to complete this study. Ten limbs were randomly assigned to a 3-screw construct. The other 10 contralateral limbs were assigned to a commercially available 5-hole locking plate (5 stainless steel and 5 titanium alloy) with an interfragmentary lag screw construct. The first rays were then isolated and potted into a 4-point bending device. The specimens were loaded to failure in a servohydraulic load frame at a controlled rate. Failure was defined as catastrophic or 3 mm of plantar gapping at the arthrodesis site. The mean maximal load to failure was 310.9 ± 109.4 N for the 3-screw construct. The mean maximal load to failure for the locking plate constructs was 264.1 ± 100.9 N. This difference was not statistically significant (p = .328). These results suggest that a 3-screw construct for Lapidus arthrodesis is as strong as commercially available locking plate constructs.
改良的 Lapidus 拇囊炎切除术是一种纠正拇外翻畸形的有效且非常强大的方法。传统上保留用于“严重”畸形，这种手术在足病学界最近重新兴起，因为它具有独特的能力，可以实现这种具有挑战性的畸形的三平面矫正。尽管该手术已在生物力学实验室和临床领域进行了广泛研究，但对于这种发人深省的手术，尚未达成关于最佳固定的明确共识。目前的研究在控制环境下检查了具有骨间加压的商业上可用的 5 孔锁定板与交叉螺钉与第三个“贯穿”螺钉构造之间的强度差异。使用十个新鲜冷冻的尸体匹配对肢体（总共 20 个肢体）完成了这项研究。十个肢体被随机分配到 3 螺钉构造。另外 10 个对侧肢体被分配到具有骨间加压的商业上可用的 5 孔锁定板（5 个不锈钢和 5 个钛合金）与带有骨间加压的交锁螺钉构造。然后将第一射线分离并植入四点弯曲装置中。将标本在装有液压的负载框架中以受控的速度加载至失效。失效定义为灾难性的或融合部位出现 3 毫米的足底间隙。3 螺钉构造的平均最大失效负载为 310.9 ± 109.4 N。锁定板构造的平均最大失效负载为 264.1 ± 100.9 N。差异无统计学意义（p=0.328）。这些结果表明，Lapidus 融合术的 3 螺钉构造与市售锁定板构造一样坚固。
