Kramer Aviv, Allon Raviv, Werner Frederick, Lavi Idit, Wolf Alon, Wollstein Ronit
School of Medicine, Technion Israel Institute of Technology, Haifa, Israel.
Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, New York.
J Wrist Surg. 2018 Nov;7(5):366-374. doi: 10.1055/s-0038-1660811. Epub 2018 Jun 17.
In joints, structure dictates function and consequently pathology. Interpreting wrist structure is complicated by the existence of multiple joints and variability in bone shapes and anatomical patterns in the wrist. Previous studies evaluated lunate and capitate shape in the midcarpal joint, and two distinct patterns have been identified. Our purpose was to further characterize the two wrist patterns in normal wrist radiographs using measurements of joint contact and position. Our hypothesis was that we will find significant differences between the two distinct anatomical patterns. A database of 172 normal adult wrist posteroanterior (PA) radiographs was evaluated for radial inclination, height, length, ulnar variance, volar tilt, radial-styloid-scaphoid distance, and lunate and capitate types. We measured and calculated percent of capitate facet that articulates with the lunate, scapholunate ligament, scaphoid, and trapezoid. These values were compared between the wrist types and whole population. Type-1 wrists (lunate type-1 and spherical proximal capitate) were positively associated with a longer facet between capitate and distal lunate ( = 0.01), capitate and base of middle metacarpal ( = 0.004), and shorter facet between the capitate and hamate ( = 0.004). The odds ratio of having a type-1 wrist when the interface between the capitate and lunate measures >8.5 mm is 2.71 (confidence interval [CI] 1.07, 6.87) and when the line between the capitate and the base of middle metacarpal >9.5 mm is 3.5 (CI 1.38, 9.03). We characterized the two-wrist patterns using intracarpal measurements. Translating these differences into three-dimensional contact areas may help in the understanding of biomechanical transfer of forces through the wrist. This is a Level II, diagnostic study.
在关节中，结构决定功能，进而决定病理情况。腕部存在多个关节，且腕骨形状和解剖模式具有变异性，这使得解读腕部结构变得复杂。先前的研究评估了腕中关节月骨和头状骨的形状，并确定了两种不同的模式。
我们的目的是通过测量关节接触和位置，进一步描述正常腕部X线片上的两种腕部模式。我们的假设是，我们将发现这两种不同解剖模式之间存在显著差异。
对一个包含172张正常成人腕部后前位（PA）X线片的数据库进行评估，测量桡骨倾斜度、高度、长度、尺骨变异、掌倾角、桡骨茎突-舟骨距离以及月骨和头状骨类型。我们测量并计算了与月骨、舟月韧带、舟骨和大多角骨相关的头状骨关节面百分比。对这两种腕部类型以及总体人群的这些值进行了比较。
1型腕（月骨1型和球形近端头状骨）与头状骨和远侧月骨之间较长的关节面（P = 0.01）、头状骨和第二掌骨基部之间较长的关节面（P = 0.004）以及头状骨和钩骨之间较短的关节面（P = 0.004）呈正相关。当头状骨与月骨之间的界面测量值>8.5 mm时，具有1型腕的优势比为2.71（置信区间[CI] 1.07, 6.87），当头状骨与第二掌骨基部之间的连线>9.5 mm时，优势比为3.5（CI 1.38, 9.03）。
我们通过腕内测量来描述这两种腕部模式。将这些差异转化为三维接触面积可能有助于理解通过腕部的力的生物力学传递。
这是一项II级诊断性研究。
