Wyss U P, Cooke T D, Yoshioka Y, Bryant J T, Siu D, Murphy L
Clinical Mechanics Group, Queen's University, Kingston, Ontario, Canada.
J Biomed Eng. 1989 Jan;11(1):19-24. doi: 10.1016/0141-5425(89)90160-x.
Joint replacement is one of many options for the treatment of the first metatarsophalangeal (MTP) joint. Studies of the geometry of that joint have shown that it consists of two distinct articulations, the metatarsophalangeal and the MT-sesamoidal. Both are important, but the MT-sesamoidal tolerates only small deviations from an ideal alignment. The aim of this study was to investigate the alignment of the first MTP joint of a potential patient population, in order to design an optimal surface replacement. One measurement, the extension angle between the MT and the proximal phalanx was found to be the most important alignment criterion for the successful design of an implant and the necessary instruments. This angle controls the delicate interplay between the metatarsal head and the sesamoids and tolerates only small deviations from the normal range before the chance of sesamoidal subluxation increases significantly. The pre-operative knowledge of this and other alignment criteria is important for the ideal placement of an anatomical implant.
关节置换是治疗第一跖趾关节（MTP）的众多选择之一。对该关节几何结构的研究表明，它由两个不同的关节组成，即跖趾关节和跖骨-籽骨关节。两者都很重要，但跖骨-籽骨关节只能耐受与理想对线的微小偏差。本研究的目的是调查潜在患者群体的第一跖趾关节对线情况，以便设计出最佳的表面置换方案。一种测量方法，即跖骨与近节趾骨之间的伸展角度，被发现是成功设计植入物和必要器械的最重要对线标准。这个角度控制着跖骨头与籽骨之间微妙的相互作用，并且在籽骨半脱位的几率显著增加之前，只能耐受与正常范围的微小偏差。术前了解这一对线标准和其他对线标准对于解剖型植入物的理想放置很重要。
