Arik Atilla, Tanrikulu Seval, Demiray Taylan, Leblebicioglu Gursel
Department of Orthopedics and Traumatology, Hand Surgery, Adana City Training and Research Hospital, Adana, Turkey.
Department of Orthopedics and Traumatology, Hand Surgery, Koç University Faculty of Medicine, Istanbul, Turkey.
J Hand Surg Asian Pac Vol. 2020 Mar;25(1):95-103. doi: 10.1142/S2424835520500137.
Palmar tilt and ulnar variance are crucial parameters for evaluating the distal radius. Identifying suitable reference points for these parameters on lateral wrist radiographs remains challenging. The purpose of this study was to establish reference points for measuring palmar tilt and ulnar variance on lateral wrist radiographs and to evaluate the reliability of these two parameters using the newly defined reference points. The distal articular surfaces of 25 cadaver radii were marked at four different locations using thin wires. These bones were radiographed and constant landmarks were recorded. The reliability of the palmar tilt and ulnar variance measurements was assessed using the new reference points and two serial measurements recorded by three observers on 27 standardized lateral wrist radiographs. The reference points for palmar tilt on lateral radiograph were the dorsal and volar end points of the subchondral line. The subchondral line was connected to two of five metaphyseal cortical lines. The reference point for lateral ulnar variance was easily defined on the midpoint of the proximal aspect of the subchondral line. The corresponding posteroanterior central reference point for ulnar variance was at the ulnar corner of the subchondral line. Inter- and intra-observer reliabilities were overall good for the palmar tilt measurements, and excellent for the ulnar variance measurements. Palmar tilt can be determined accurately with a good understanding of the radiographic landmarks on lateral radiographs, and by addressing the problems caused by ulnar inclination of the articular surface of the distal radius. Lateral wrist radiographs can provide a complete picture of the ulnar border of the radius for measuring ulnar variance.
掌倾角和尺骨变异是评估桡骨远端的关键参数。在腕关节侧位X线片上确定这些参数的合适参考点仍然具有挑战性。本研究的目的是在腕关节侧位X线片上建立测量掌倾角和尺骨变异的参考点，并使用新定义的参考点评估这两个参数的可靠性。使用细钢丝在25具尸体桡骨的远端关节面的四个不同位置进行标记。对这些骨骼进行X线摄影并记录恒定的标志点。使用新的参考点以及三名观察者在27张标准化腕关节侧位X线片上记录的两次连续测量结果，评估掌倾角和尺骨变异测量的可靠性。腕关节侧位片上掌倾角的参考点是软骨下线的背侧和掌侧端点。软骨下线与五条干骺端皮质线中的两条相连。尺骨侧变异的参考点很容易在软骨下线近端的中点处确定。尺骨变异相应的前后位中央参考点位于软骨下线的尺侧角。观察者间和观察者内的可靠性对于掌倾角测量总体良好，对于尺骨变异测量则非常出色。通过很好地理解腕关节侧位片上的影像学标志，并解决由桡骨远端关节面尺侧倾斜引起的问题，可以准确确定掌倾角。腕关节侧位片可以提供桡骨尺侧缘的完整图像以测量尺骨变异。
