Tan Virak, Kinchelow Tosca, Beredjiklian Pedro K
Department of Orthopaedics, Division of Hand, Upper Extremity and Microvascular Surgery, UMDNJ-NJ Medical School, Newark, NJ 07103, USA.
J Hand Surg Am. 2008 Jul-Aug;33(6):873-8. doi: 10.1016/j.jhsa.2008.02.006.
The purpose of this study is to quantify finger/digit rotation, overlap, parallelism, and convergence to the scaphoid tuberosity in normal volunteers to establish standards for comparison.
We examined 240 uninjured fingers in 30 volunteers. There were 14 men and 16 women with an average age of 35 years. Rotation was determined with the palm flat and fingers extended. Digit overlap, parallelism (angular relationship between the index, ring, and small fingers with respect to the middle finger) and scaphoid convergence were determined with simultaneous flexion of metacarpophalangeal and proximal interphalangeal joints. Linear and angular measurements were performed with imaging software.
Rotation, parallelism, and scaphoid convergence measurements were similar comparing left with right hands. Rotation: All digits were found to be in supination relative to the horizontal plane; the small fingers averaged 9 degrees, the ring fingers 4 degrees, the middle fingers 8 degrees, and the index fingers 12 degrees. Parallelism: Angular measurements between the middle finger and the small finger averaged 19 degrees, between the middle finger and the ring finger 9 degrees, and between the middle finger and the index finger 11 degrees. Scaphoid convergence: In no hand did all 4 fingers converge onto scaphoid tuberosity. Whereas small and ring finger trajectories averaged -0.1 to 1.2 mm from the scaphoid tubercle, the middle finger averaged 4.0 to 4.6 mm and the index finger 8.1 to 9.5 mm. Overlap: Ninety percent of individuals demonstrated digit overlap, although none covered more than 50% of the adjacent nail plate. Seventy-seven percent of these were bilateral, and 73% were asymmetric.
This study establishes the normal parameters for digit rotation, overlap, parallelism, and scaphoid convergence. For digit rotation, parallelism, and scaphoid convergence, the contralateral (uninjured) hand can be used reliably for comparison. However, for digit overlap, the contralateral hand should not be used for comparison because of side-to-side asymmetry and variability.
TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.
本研究旨在对正常志愿者手指/指骨的旋转、重叠、平行度以及向舟骨结节的汇聚情况进行量化，以建立可供比较的标准。
我们对30名志愿者的240根未受伤手指进行了检查。其中男性14名，女性16名，平均年龄35岁。手掌平放且手指伸展时测定旋转情况。掌指关节和近端指间关节同时屈曲时测定指骨重叠、平行度（示指、环指和小指相对于中指的角度关系）以及向舟骨的汇聚情况。使用成像软件进行线性和角度测量。
左右手的旋转、平行度和向舟骨汇聚度测量结果相似。旋转：所有手指相对于水平面均处于旋后位；小指平均为9度，环指为4度，中指为8度，示指为12度。平行度：中指与小指之间的角度测量平均值为19度，中指与环指之间为9度，中指与示指之间为11度。向舟骨汇聚：没有一只手的4根手指都汇聚到舟骨结节上。小指和环指的轨迹平均距离舟骨结节-0.1至1.2毫米，中指平均为4.0至4.6毫米，示指为8.1至9.5毫米。重叠：90%的个体存在指骨重叠，尽管没有一个覆盖超过相邻指甲板的50%。其中77%为双侧性，73%不对称。
本研究确立了手指旋转、重叠、平行度和向舟骨汇聚的正常参数。对于手指旋转、平行度和向舟骨汇聚，对侧（未受伤）手可可靠地用于比较。然而，对于指骨重叠，由于左右不对称和变异性，不应使用对侧手进行比较。
研究类型/证据水平：诊断性IV级。
