Aper R L, Saltzman C L, Brown T D
Department of Orthopaedic Surgery, University of Iowa, Iowa City 52242.
Foot Ankle Int. 1994 Sep;15(9):462-70. doi: 10.1177/107110079401500902.
In this cadaver study, the functional significance of the hallux sesamoid bones was quantified by measuring the effective tendon moment arm (ETMA) of the flexor hallucis brevis (FHB) force. (The ETMA differs from the anatomic tendon moment arm in that ETMAs are determined by the experimentally measured moment of the tendon force, rather than by the actual location and orientation of the tendon pull in the joint). The intact case was compared with three levels of progressive sesamoid resection: distal half of the medial sesamoid excised, entire medial sesamoid excised, and both the medial and lateral sesamoids excised. Five dorsiflexion angles of the metatarsophalangeal joint were tested, ranging from -10 degrees to 50 degrees. A known active load was applied to the FHB muscle of fresh frozen cadaver specimens while the corresponding resisting forces from three orthogonally mounted transducers were being recorded. Results showed that the ETMAs decreased significantly (P < .05) only with the excision of both sesamoids. The percent decrease in ETMA was smallest at dorsiflexion angles of -10 degrees and 15 degrees (4.3% and 2.4%, respectively) and largest at dorsiflexion angles of 25 degrees, 35 degrees, and 50 degrees (29.2%, 22.4%, and 26.7%, respectively). The clinical significance of the results is that distal hemiresection of the medial sesamoid or full medial sesamoid excision is unlikely to appreciably compromise the effective mechanical advantage of the FHB muscle. However, this mechanical advantage may be profoundly diminished by excision of both hallux sesamoids.
在这项尸体研究中，通过测量拇短屈肌（FHB）力量的有效肌腱力臂（ETMA），对拇籽骨的功能意义进行了量化。（ETMA与解剖学肌腱力臂的不同之处在于，ETMA是由肌腱力的实验测量力矩确定的，而不是由关节中肌腱拉力的实际位置和方向确定的）。将完整的情况与三个逐渐进行的籽骨切除水平进行比较：切除内侧籽骨的远端一半、切除整个内侧籽骨以及切除内侧和外侧籽骨。测试了跖趾关节的五个背屈角度，范围从-10度到50度。在记录来自三个正交安装的传感器的相应阻力时，向新鲜冷冻尸体标本的FHB肌肉施加已知的主动负荷。结果表明，仅在切除两侧籽骨时，ETMA才显著降低（P < 0.05）。ETMA的降低百分比在背屈角度为-10度和15度时最小（分别为4.3%和2.4%），在背屈角度为25度、35度和50度时最大（分别为29.2%、22.4%和26.7%）。这些结果的临床意义在于，内侧籽骨的远端半切除或内侧籽骨全切不太可能明显损害FHB肌肉的有效机械优势。然而，切除两侧拇籽骨可能会极大地削弱这种机械优势。
