Kurosawa Kazuya, Tsuchiya Ichiro, Takagishi Kenji
Department of Orthopaedic Surgery, Hidaka Hospital, Takasaki, Gunma, Japan.
J Hand Surg Am. 2013 Feb;38(2):302-8. doi: 10.1016/j.jhsa.2012.09.027. Epub 2012 Nov 28.
Dorsal subluxation of the base of the first metacarpal is a typical finding in trapezial-metacarpal (TM) osteoarthritis. The purpose of this study was to clarify the correlation between dorsal subluxation and articular tilt of the metacarpal facet in TM osteoarthritis.
We investigated 50 subjects between 25 and 70 years of age (mean, 45 ± 11 y) with normal thumbs (100 hands) and 98 subjects between 43 and 89 years of age (mean, 61 ± 11 y) with TM osteoarthritis (132 hands). We established 3 groups: normal (normal thumbs), mild arthritis (40 hands, Eaton stage 1 or 2), and severe arthritis (92 hands, Eaton stage 3 or 4). We took sagittal-plane radiographs of all TM joints. We defined the dorsal subluxation angle as the angle formed by a tangent drawn on the dorsal margin of the first metacarpal base and trapezium and the longitudinal axis of the second metacarpal. The facet angle was defined as the complementary angle between the tangent to the dorsal cortex of the first metacarpal and the line of the metacarpal facet of the TM joint. We compared the dorsal subluxation angle and facet angle between groups and investigated the correlation between these angles among the 132 hands with TM osteoarthritis.
Both the dorsal subluxation angle and facet angle were significantly greater in the mild arthritis group than in the normal group and significantly greater in the severe arthritis group than in the mild arthritis group. A significant moderately positive correlation was also apparent between dorsal subluxation and facet angle in patients with TM osteoarthritis.
Articular tilt and dorsal subluxation of the first metacarpal base are closely related, and both are increased with advanced-stage TM osteoarthritis.
TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.
第一掌骨基部背侧半脱位是大多角骨-掌骨（TM）骨关节炎的典型表现。本研究的目的是阐明TM骨关节炎中背侧半脱位与掌骨关节面关节倾斜之间的相关性。
我们调查了50名年龄在25至70岁之间（平均45±11岁）的拇指正常者（100只手）以及98名年龄在43至89岁之间（平均61±11岁）的TM骨关节炎患者（132只手）。我们分为3组：正常组（拇指正常）、轻度关节炎组（40只手，伊顿1期或2期）和重度关节炎组（92只手，伊顿3期或4期）。我们对所有TM关节进行矢状面X线摄影。我们将背侧半脱位角定义为在第一掌骨基部和大多角骨背侧边缘画的切线与第二掌骨纵轴所形成的角。关节面角定义为第一掌骨背侧皮质切线与TM关节掌骨关节面线之间的余角。我们比较了各组之间的背侧半脱位角和关节面角，并研究了132只患有TM骨关节炎的手的这些角度之间的相关性。
轻度关节炎组的背侧半脱位角和关节面角均显著大于正常组，重度关节炎组显著大于轻度关节炎组。TM骨关节炎患者的背侧半脱位与关节面角之间也存在显著的中度正相关。
第一掌骨基部的关节倾斜和背侧半脱位密切相关，并且两者都随着晚期TM骨关节炎而增加。
研究类型/证据水平：治疗性III级。
