ABC Medical Center, Mexico City, Mexico.
Tufts Medical School, Boston, MA, USA.
J Anat. 2021 Sep;239(3):663-668. doi: 10.1111/joa.13446. Epub 2021 Apr 25.
This study aimed to determine by ultrasonography, and cadaveric dissection, whether the firm cords felt by palpation at the sides of the proximal phalanx (PP), actively flexing, and extending the proximal interphalangeal (PIP) joint while keeping the metacarpophalangeal (MCP) joint extended are the lateral bands (LBs) of the extensor apparatus. If so, palpation of the LBs could help evaluate hand conditions that impact the digits' intrinsic muscles. To this end, the PP of the middle and ring fingers of the dominant hand of seven subjects were studied by palpation on both sides. Ultrasonography (US) was performed with a hockey-stick transducer placed on the ulnar side. Five cadaveric hands were dissected, exposing the dorsal extensor apparatus. On palpation, a firm cord was consistently felt at the PP's sides in all subjects. These cords moved widely forward on PIP flexion and backward with PIP extension. By US scanning, the cords corresponded to the LBs. However, the forward movement had only a median of 1.8 mm (range 0.7-3 mm) in the middle finger and a median of 1.1 mm (range 0.3-2.7 mm) in the ring finger compared with an estimated 5-10 mm upon palpation. Cadaveric dissection confirmed the forward movement of the LBs in PIP flexion. We concluded that the firm cords felt at the PP sides are the LBs of the extensor apparatus. We confirmed their movement with the active flexion/extension of the PIP joint. Comparing the wide palpatory and the meager US motion, a haptic illusion of motion may be present.
本研究旨在通过超声检查和尸体解剖确定，在主动弯曲和伸展近侧指间关节（PIP）同时保持掌指关节（MCP）伸展时，触诊感觉到近端指骨（PP）两侧的坚韧条索是否为伸肌装置的侧束（LBs）。如果是这样，那么触诊 LBs 可能有助于评估影响手指内在肌肉的手部状况。为此，对 7 名受试者的优势手的中指和环指指节的 PP 两侧进行了触诊研究。使用放置在尺侧的曲棍球棒换能器进行超声检查（US）。对 5 只尸体手进行了解剖，暴露了背侧伸肌装置。在触诊时，所有受试者的 PP 两侧都能感觉到一条坚韧的条索。这些条索在 PIP 弯曲时广泛向前移动，在 PIP 伸展时向后移动。通过 US 扫描，这些条索与 LBs 相对应。然而，与触诊时估计的 5-10 毫米相比，在中指的向前移动仅有 1.8 毫米（范围 0.7-3 毫米），在环指的向前移动仅有 1.1 毫米（范围 0.3-2.7 毫米）。尸体解剖证实了 PIP 弯曲时 LBs 的向前运动。我们得出结论，PP 两侧感觉到的坚韧条索是伸肌装置的 LBs。我们通过主动弯曲/伸展 PIP 关节确认了它们的运动。与广泛的触诊运动和微薄的 US 运动相比，可能存在触觉幻觉运动。
