PDF(Pubmed)
Abstract：
Previous studies of midterm fetuses indicated that a cartilaginous fabella appeared to be embedded in the plantaris (PL), and was fused with the gastrocnemius lateral head (GL). We re-examined the topographical anatomy of the fabella or its analogue (a tight fibrous mass) originating in the GL and/or PL by evaluating histological sections of the unilateral knees of 15 late-term fetuses. Regardless of whether the cartilaginous fabella was present (6 fetuses) or absent (9 fetuses), the origins of the PL and GL muscles each had three parts. In each fetus, the fabella or its analogue was embedded in a thick common tendinous origin of the GL and PL. PL1 (whose origin is similar to that of the adult PL) originated from the femoral condyle immediately above the common tendon; PL2 originated from the posteromedial aspect of the fabella or its analogue; and PL3 originated from the inferior aspect of the fabella or its analogue. The muscle fibers of PL1, PL2, and PL3 joined to provide a thick plantaris. GL1 (which is adjacent to PL2) originated from the common tendon in the superior side of the fabella or its analogue and GL2 originated from the inferior side of the fabella or its analogue. GL1 and GL2 joined to provide a thick bundle, whereas GL3 (located far below the fabella or its analogue) originated from the posterior surface aponeurosis. Therefore, drastic reconstruction at these muscle origins was necessary during development. Due to the strong mechanical stress from the GL and the space-occupying effect of the muscle, we hypothesize that PL2 and PL3 are degraded or absorbed into the GL1 and GL2 during the postnatal period, so that the remaining PL1 was likely the remaining PL in adults.
摘要：
先前对中期胎儿的研究表明，软骨fabella似乎嵌入在足底（PL）中，并与腓肠肌侧头（GL）融合。我们通过评估15个晚期胎儿的单侧膝盖的组织学切片，重新检查了源自GL和/或PL的fabella或其类似物（紧密的纤维团）的地形解剖结构。无论软骨fabella是否存在（6个胎儿）或不存在（9个胎儿），PL和GL肌肉的起源各有三部分。在每个胎儿中，fabella或其类似物嵌入了GL和PL的厚厚的共同肌腱起源。PL1（其起源与成人PL相似）起源于普通肌腱上方的股骨髁；PL2起源于fabella或其类似物的后内侧；PL3起源于fabella或其类似物的下部。PL1、PL2和PL3的肌纤维连接以提供厚厚的足底。GL1（与PL2相邻）起源于fabella或其类似物上侧的普通肌腱，而GL2起源于fabella或其类似物的下侧。GL1和GL2连接以提供粗束，而GL3（位于fabella或其类似物下方）起源于后表面膜。因此,在发育过程中，这些肌肉起源的剧烈重建是必要的。由于来自GL的强烈机械应力和肌肉的占据空间效应，我们假设PL2和PL3在出生后被降解或吸收到GL1和GL2中，因此，剩余的PL1可能是成年人中剩余的PL。
