Bronenberg Victorica Pedro, Shapiro Lauren M, Chan Calvin, De Carli Pablo, Castro Appiani Luis Miguel, Kamal Robin N
Hand and Upper Extremity Surgery Department, Instituto Carlos E. Ottolenghi, Hospital Italiano, Buenos Aires, Argentina.
Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA.
J Hand Surg Am. 2025 Oct;50(10):1271.e1-1271.e8. doi: 10.1016/j.jhsa.2024.10.014. Epub 2024 Nov 26.
Although studies have demonstrated that locked screws with a length of 75% of the radius width are sufficient for the treatment of extra-articular fractures of the distal radius, the application of this principle to intra-articular fractures is less well-understood. This study aimed to evaluate the biomechanical properties of different types of volar plate fixation constructs for the treatment of distal radius fractures in the presence of a dorsal critical corner fragment.
A dorsal critical corner fracture was created in 18 synthetic distal radius models. The fragment was stabilized with one of three constructs: a posteroanterior integrated compression screw (group 1) or volar locking screws with a length of 90% or 75% of the volar/dorsal width of the radius (groups 2 and 3, respectively). For the biomechanical evaluation, a load was applied to the lunate facet. Fixation stiffness and loads to produce clinical and catastrophic failures were compared among the groups.
The stiffness (N/mm) was 67.8 (SD, 14.7), 64.9 (SD, 8.63), and 65.8 (SD, 36.02) for groups 1, 2, and 3, respectively. The load required to generate a catastrophic displacement was 532.9 (SD, 142.32), 307.4 (SD, 101.51), and 230.8 N (SD, 77.68) for groups 1, 2, and 3, respectively. The load required to produce a 2-mm translation of the fixed fragment was 127.9 N (SD, 28.8) for group 1, 119.7 (SD, 11.78) for group 2, and 127.6 N (SD, 46.2) for group 3.
Significantly greater load is required for catastrophic failure after fixation of a dorsal critical corner fracture with an integrated compression screw; however, it provides similar stiffness and load to failure for 2 mm of translation.
For the treatment of intra-articular distal radius fractures with dorsal critical corner fragments, an integrated compression screw may be considered for rigid fixation of the fragment to support early return to daily activities.
尽管研究表明长度为桡骨宽度75%的锁定螺钉足以治疗桡骨远端关节外骨折，但该原则在关节内骨折中的应用尚不太清楚。本研究旨在评估在存在背侧关键角骨折块的情况下，不同类型掌侧钢板固定结构治疗桡骨远端骨折的生物力学性能。
在18个合成桡骨远端模型上制造背侧关键角骨折。骨折块用三种结构之一进行固定：前后一体式加压螺钉（第1组）或长度为桡骨掌侧/背侧宽度90%或75%的掌侧锁定螺钉（分别为第2组和第3组）。为进行生物力学评估，向月骨小面施加负荷。比较各组的固定刚度以及产生临床和灾难性失败的负荷。
第1组、第2组和第3组的刚度（N/mm）分别为67.8（标准差，14.7）、64.9（标准差，8.63）和65.8（标准差，36.02）。第1组、第2组和第3组产生灾难性移位所需的负荷分别为532.9（标准差，142.32）、307.4（标准差，101.51）和230.8 N（标准差，77.68）。使固定骨折块产生2 mm移位所需的负荷，第1组为127.9 N（标准差，28.8），第2组为119.7（标准差，11.78），第3组为127.6 N（标准差，46.2）。
用一体式加压螺钉固定背侧关键角骨折后发生灾难性失败所需的负荷显著更大；然而，对于2 mm的移位，它提供了相似的刚度和失败负荷。
对于伴有背侧关键角骨折块的关节内桡骨远端骨折的治疗，可考虑使用一体式加压螺钉对骨折块进行坚强固定，以支持早期恢复日常活动。
