Anatomical Study of Radial Tunnel and its Clinical Implications in Compressive Syndromes / Estudo anatômico do túnel radial e suas implicações nas síndromes compressivas

Abstract Objective The purpose of the present study was to analyze the structures in the radial tunnel that can cause posterior interosseous nerve entrapment. Methods A total of 30 members of 15 adult cadavers prepared by intra-arterial injection of a 10% solution of glycerol and formalin were dissected. All were male, belonging to the laboratory of anatomy of this institution. Results The branch for the supinator muscle originated from the posterior interosseous nerve in all limbs. We identified the Frohse arcade with a well-developed fibrous constitution in 22 of the 30 dissected limbs (73%) and of muscular constitution in 8 (27%). The distal margin of the supinator muscle presented fibrous consistency in 7 of the 30 limbs (23.5%) and muscular appearance in 23 (76.5%). In the proximal margin of the extensor carpi radialis brevis muscle, we identified the fibrous arch in 18 limbs (60%); in 9 (30%) we noticed the arcade of muscular constitution; in 3 (10%) there was only the radial insertion, so that it did not form the arcade. Conclusion The Frohse arcade and the arcade formed by the origins of the extensor carpi radialis brevis are normal anatomical structures in adult cadavers. However, from the clinical point of view, these structures have the potential to cause entrapment of the posterior interosseous nerve.

Resumo Objetivo O objetivo do presente estudo foi analisar as estruturas contidas no túnel radial que podem causar neuropatia compressiva do nervo interósseo posterior. Métodos Foram dissecados 30 membros de 15 cadáveres adultos, preparados por injeção intra-arterial de uma solução de glicerina e formol a 10%. Todos do sexo masculino, pertencentes ao laboratório de anatomia desta instituição. Resultados O ramo para o músculo supinador originou-se do nervo interósseo posterior em todos os membros. Identificamos a arcada de Frohse com uma constituição fibrosa bem desenvolvida em 22 dos 30 membros dissecados (73%) e de constituição muscular em 8 (23%) A margem distal do músculo supinador apresentou consistência fibrosa em 7 dos 30 membros (23,5%) e uma aparência muscular em 23 (76,5%). Na margem proximal do músculo extensor radial curto do carpo, identificamos a arcada fibrosa em 18 membros (60%); em 9 (30%), notamos a arcada de constituição muscular; e em três (10%) havia apenas a inserção radial, de maneira que não formava a arcada. Conclusão A arcada de Frohse e a arcada formada pelas origens do músculo extensor radial curto do carpo são estruturas anatômicas normais em cadáveres adultos. No entanto, sob o ponto de vista clínico, essas estruturas têm potencial para causar a compressão do nervo interósseo posterior.

Anastomosis between the deep branch of ulnar nerve and a branch of the median nerve (Cannieu-Riché anastomosis) and thenar muscles innervation: anatomical study and clinical implications / Anastomosis entre el ramo profundo del nervio ulnar y un ramo del nervio mediano (anastomosis de Cannieu-Riché) e inervación de la eminencia tenar: estudio anatómico e implicaciones clínicas

SUMMARY: The aim of this paper was to report the incidences of the anastomosis between deep branch of ulnar nerve and a branch of the median nerve commonly named Cannieu-Riché anastomosis (CRA) and thenar muscles innervation. The anatomical dissection of 80 limbs from 40 fresh adult cadavers were performed in the Department of Anatomy at the Medical School of the Catholic University of São Paulo. The incidence of CRA and thenar muscle innervation were studied. The CRA was found in all of the dissected hands (100 %). The abdutor pollicis brevis and the opponens pollicis muscle are innervated exclusively by median nerve in all dissected hands. The superficial head of flexor pollicis brevis was innervated by the median nerve in of 56 the hands (70 %), in 24 (30 %) it had double innervation (median nerve and deep branch of ulnar nerve). The deep head of flexor pollicis brevis were absent in 11 hands (14 %), in 52 hands (65 %), a double innervation was observed. In 14 (17.5 %) exclusively by deep branch of ulnar nerve and in 3 hands (3.6 %) exclusively by a branch of median nerve. The oblique head of adductor pollicis muscle was innervated only by deep branch of ulnar nerve in 66 hands (82 %) of dissected hands, 14 (17.5 %) had a double innervation. The transverse head of adductor pollicis was innervated exclusively by deep branch of ulnar nerve in 77 hands (96.4 %), and in 3 (3.6 %) had a double innervation. According to our study the pattern of innervation was more frequent in relation to the flexor pollicis brevis muscle and should be considered as a normal pattern, in that the superficial head receives innervation of branches of median nerve, and the deep head receives innervation of deep branch of ulnar nerve and branches of median nerve (dual innervation). The abductor pollicis brevis and opponens pollicis received innervation exclusively by median nerve. Both the oblique and transverse head of adductor pollicis exclusively by ulnar nerve. The RCA was found in all of the dissected hands (100 %).

RESUMEN: El objetivo de este trabajo fue informar la anastomosis entre el ramo profundo del nervio ulnar y un ramo del nervio mediano (Anastomosis de Cannieu-Riché) y de la inervación de los músculos de la eminencia tenar. Se realizó la disección anatómica de 80 miembros de 40 cadáveres adultos frescos en el Departamento de Anatomía de la Facultad de Medicina de la Universidad Católica de São Paulo, Brasil. Se estudió la incidencia de formación de la ACR y la inervación de los músculos tenares. La ACR se encontró en todas las manos disecadas (100 %). El músculo abductor corto del pulgar y el músculo oponente del pulgar recibían inervación exclusivamente por el nervio mediano en todas las manos disecadas. La cabeza superficial del músculo flexor corto del pulgar estaba inervada por el nervio mediano (70 %), en 24 casos, (30 %) presentó inervación doble (nervio mediano y ramo profundo del nervio ulnar). La cabeza profunda del músculo flexor corto del pulgar estuvo ausente en 11 manos (14 %), mientras que en 52 manos (65 %) se produjo una doble inervación. En 14 casos (17,5 %) se vio inervado exclusivamente por el ramo profundo del nervio ulnar y en 3 manos (3,6 %) exclusivamente por un ramo del nervio mediano. La cabeza oblicua del músculo aductor del pulgar estaba inervada sólo por el ramo profundo del nervio ulnar en 66 manos (82 %), en 14 casos (17,5 %) tenía una doble inervación. La cabeza transversa del músculo aductor del pulgar estaba inervada exclusivamente por el ramo profundo del nervio ulnar en 77 manos (96,4 %), en 3 manos (3,6 %) presentó una doble inervación. De acuerdo con nuestro estudio, el patrón de inervación más frecuente en relación al músculo flexor corto del pulgar debe ser considerado como un patrón normal, en el que la cabeza superficial recibe inervación de ramos del nervio mediano y la cabeza profunda recibe inervación del ramo profundo de nervio ulnar y ramos del nervio mediano (inervación dual). El músculo abductor corto del pulgar y el músculo oponente del pulgar recibieron inervación exclusivamente por el nervio mediano. Tanto la cabeza oblicua como transversa del músculo aductor del pulgar están inervadas exclusivamente por el nervio ulnar. La ACR se encontró en todas las manos disecadas (100 %).