Elhassan Bassem, McNeal David, Wynn Shawn, Gonzalez Mark, Amirouch Farid
Department of Orthopedics, University of Illinois at Chicago, Chicago, IL 60612, USA.
J Hand Surg Am. 2006 Feb;31(2):228-35. doi: 10.1016/j.jhsa.2005.09.015.
The purpose of this study was to quantify the changes in the arc of digital flexion before and after metacarpophalangeal (MCP) silicone arthroplasty with a 30 degrees preflexed design.
Index, middle, and ring fingers of 4 fresh-frozen cadaver hands were used. Each hand was attached (palmar side up) to a custom test apparatus. The tendon was drawn by a small winch-type servomotor. Micropotentiometers that were attached to the centers of rotation of the MCP, distal interphalangeal, and proximal interphalangeal joints measured angular displacement before and after MCP arthroplasty as a function of tendon excursion. The data were analyzed comparing the angle of flexion initiation and the angular displacement as a function of tendon excursion before and after joint arthroplasty.
There were no statistical differences in the angles of the MCP joints at rest, the order of initiation of joint flexion, and the overall degree of flexion between the unoperated fingers and the fingers that had surgery. There was, however, a trend toward delay in flexion initiation, an increase in the MCP angle at rest, and a decrease in torque after implant arthroplasty.
The decrease in initiation of flexion of the MCP joint, although not statistically significant, probably was related to the 30 degrees of preflexion built into the implant. We also noted a trend of decreased flexion at the MCP joint and increased flexion at the proximal interphalangeal and distal interphalangeal joints. This trend may be advantageous in the reconstruction of hands that initially have an MCP joint flexion deformity.
TYPE OF STUDY/LEVEL OF EVIDENCE: to come.
本研究旨在量化采用30度预屈曲设计的掌指（MCP）硅胶关节成形术前后手指屈曲弧度的变化。
使用4只新鲜冷冻尸体手的示指、中指和环指。每只手（掌心向上）固定在定制的测试装置上。肌腱由小型绞盘式伺服电机牵拉。附着在MCP、远侧指间关节和近侧指间关节旋转中心的微型电位计测量MCP关节成形术前后作为肌腱移动函数的角位移。分析数据以比较关节成形术前后屈曲起始角度和作为肌腱移动函数的角位移。
未手术手指和接受手术的手指在MCP关节静止角度、关节屈曲起始顺序以及总体屈曲程度方面无统计学差异。然而，植入关节成形术后存在屈曲起始延迟、MCP静止角度增加和扭矩降低的趋势。
MCP关节屈曲起始的减少虽然无统计学意义，但可能与植入物内置的30度预屈曲有关。我们还注意到MCP关节屈曲减少以及近侧指间关节和远侧指间关节屈曲增加的趋势。这种趋势在最初存在MCP关节屈曲畸形的手部重建中可能具有优势。
研究类型/证据水平：待确定。
