Isa Ahaoiza D, Mcgregor Martine E, Padmore Clare E, Langohr Daniel G, Johnson James A, King Graham J W, Suh Nina
The Moncton Hospital, Moncton, New Brunswick.
University of Western Ontario, London, Ontario, Canada.
J Hand Surg Am. 2019 Aug;44(8):669-679. doi: 10.1016/j.jhsa.2019.04.007. Epub 2019 Jun 3.
To evaluate the effect of ulnar shortening on distal forearm loading following simulated dynamic motion.
Ulnar shortening was simulated using a custom-built adjustable implant to simulate up to 4 mm of ulnar shortening (-4 mm) in 9 cadaveric extremities. Load cells were placed in the distal ulna and radius to quantify axial loading. Using a wrist and forearm motion simulator, absolute and percentage loads were measured during dynamic flexion, ulnar deviation (UD), flexion dart throw (DT), and pronation.
There was a significant decrease in absolute and percentage distal ulnar loads at each interval of ulnar shortening during flexion, UD, DT, and pronation. The distal ulna bore no compressive loads, and in fact, tensile loads were measured in the ulna at 2 mm of ulnar shortening during DT and pronation, at 3 mm during flexion, and at 4 mm during UD.
A progressive decrease in distal ulnar loads with generation of tensile loads was observed with sequential ulnar shortening.
Ulnar shortening greater than 2 mm can result in tensile loading in the distal ulna. When managing ulnar impaction syndrome, excessive shortening may not be required to provide relief of symptoms.
评估在模拟动态运动后尺骨缩短对前臂远端负荷的影响。
使用定制的可调节植入物模拟尺骨缩短，在9具尸体肢体中模拟高达4毫米的尺骨缩短（-4毫米）。将测力传感器置于尺骨和桡骨远端以量化轴向负荷。使用手腕和前臂运动模拟器，在动态屈曲、尺偏（UD）、屈肌投镖动作（DT）和旋前过程中测量绝对负荷和百分比负荷。
在屈曲、UD、DT和旋前过程中，尺骨缩短的每个阶段，尺骨远端的绝对负荷和百分比负荷均显著降低。尺骨远端未承受压缩负荷，事实上，在DT和旋前过程中尺骨缩短2毫米时、屈曲过程中3毫米时以及UD过程中4毫米时，尺骨测量到拉伸负荷。
随着尺骨依次缩短，观察到尺骨远端负荷逐渐降低并产生拉伸负荷。
尺骨缩短超过2毫米可导致尺骨远端承受拉伸负荷。在处理尺骨撞击综合征时，可能无需过度缩短来缓解症状。
