Palpation of the lateral bands of the extensor apparatus of the fingers. Anatomy of a neglected clinical finding

Abstract

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.

Palpation and Ultrasonography Reveal an Ignored Function of the Inferior Belly of Omohyoid: A Case Series and a Proof-of-Concept Study

“…Palpation is useful for identifying superficial ligaments, tendons, and nerves, such as the infrapatellar branch of the saphenous nerve. This potential for palpation was demonstrated by the dynamic palpation of the lateral bands of the extensor apparatus of the fingers [ 36 ]. The authors have ongoing projects based on palpation of forearm tendons, muscles, and hand ligaments.…”

Ultrasonography, Microcomputed Tomography, and Macroscopic Preparation in an Anatomical Study of the Thoracic Limb of the Golden-Headed Lion Tamarin (Leontopithecus chrysomelas)

“…Both of them are highly accurate and sensitive in diagnosing bone and muscle lesions. Magnetic resonance imaging can be applied as a complementary technique because this imaging modality proved to be useful for the evaluation of joint morphology in other animals [16,18]. In order to interpret CT and MRI and compare them with ultrasound and gross anatomical dissection, a particularly rare species was used to verify the results-the sagittal planes of the right forearm of the marmoset.…”

“…Threedimensional computer models, simulations of biomechanics of movement, and series of images from different cross-sections make it possible to present anatomy in a wide range of non-invasive ways. CT is often used to analyse the skeletal system [11,12], whereas ultrasonography is used for soft tissues such as muscles [13][14][15][16]. However, many authors of anatomical studies still use traditional methods, which involve the preparation of dead tissues [17,18].…”