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

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...

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Detalles Bibliográficos
Autores: Canoso, Juan J, Naredo, Esperanza, Martínez Estupiñán, Lina, Mérida Velasco, José Ramón, Pascual Ramos, Virginia, Murillo González, Jorge Alfonso
Tipo de recurso: artículo
Fecha de publicación:2021
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/92011
Acceso en línea:https://hdl.handle.net/20.500.14352/92011
Access Level:acceso abierto
Palabra clave:611
dorsal aponeurosis
extensor apparatus
lateral bands
metacarpophalangeal joint
physical examination
proximal interphalangeal joint
Anatomía
2410.02 Anatomía Humana
Descripción
Sumario: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.