Sites of anesthetic block of the lateral and medial palmar metacarpal nerves in equines of indeterminate breed

Background: Local anesthesia blockage at equines claudication diagnosis besides favoring the beginning of the therapyand relieving patients pain, it allows the identification of the specific affected region and its origin, however, if it isdone incorrectly (by improper volume of anesthetics application and/or mistakenly nerve identification due to the lack ofanatomic referential) it may cause inflammation, infection or even tissue necrosis. The aim was describing anatomicallylateral and medial palmar metacarpal nerves in equines to improve diagnostic anesthetic block techniques on four metacarpophalangeal articulation joints of the specie.Materials, Methods & Results: A number of 20 thoracic limbs from 10 equines of indeterminate breed were used to befixated in 10% phormaldehyde and with a marked arterial system by water solution of red dyed latex. The structures wereidentified by dissection, and their denomination bases on Nomina Anatomica Veterinaria (N.A.V.) by the InternationalCommittee on Veterinary Gross Anatomical Nomenclature. The study had been approved by the Board of Ethics in AnimalUse of the University Center of Patos de Minas (UNIPAM), protocol n° 18/17. The lateral and medial palmar metacarpalnerves have been observed in all of the specimens originated from the deep branch of lateral palmar nerve, immediatelydistal to the intercarpal articulation. After its origin, the first nerve stretched ipsilaterally from the common trunk, whilstthe second nerve positioned counter-lateral manner after superficially crossing the interosseus muscle. Both penetrated atthe level of the mid third of the referred muscle and the metacarpal bone III and, assumed respectively a parallel medialposition to the metacarpal bone IV and lateral to the metacarpal II, being intimately associated to the palmar face of themetacarpal bone III. Distally, those nerves emerged from a palmar position to a lateral and medial to...(AU)

Sites of anesthetic block of the lateral and medial palmar metacarpal nerves in equines of indeterminate breed

Background: Local anesthesia blockage at equines claudication diagnosis besides favoring the beginning of the therapyand relieving patient’s pain, it allows the identification of the specific affected region and its origin, however, if it isdone incorrectly (by improper volume of anesthetics application and/or mistakenly nerve identification due to the lack ofanatomic referential) it may cause inflammation, infection or even tissue necrosis. The aim was describing anatomicallylateral and medial palmar metacarpal nerves in equines to improve diagnostic anesthetic block techniques on four metacarpophalangeal articulation joints of the specie.Materials, Methods & Results: A number of 20 thoracic limbs from 10 equines of indeterminate breed were used to befixated in 10% phormaldehyde and with a marked arterial system by water solution of red dyed latex. The structures wereidentified by dissection, and their denomination bases on Nomina Anatomica Veterinaria (N.A.V.) by the InternationalCommittee on Veterinary Gross Anatomical Nomenclature. The study had been approved by the Board of Ethics in AnimalUse of the University Center of Patos de Minas (UNIPAM), protocol n° 18/17. The lateral and medial palmar metacarpalnerves have been observed in all of the specimens originated from the deep branch of lateral palmar nerve, immediatelydistal to the intercarpal articulation. After its origin, the first nerve stretched ipsilaterally from the common trunk, whilstthe second nerve positioned counter-lateral manner after superficially crossing the interosseus muscle. Both penetrated atthe level of the mid third of the referred muscle and the metacarpal bone III and, assumed respectively a parallel medialposition to the metacarpal bone IV and lateral to the metacarpal II, being intimately associated to the palmar face of themetacarpal bone III. Distally, those nerves emerged from a palmar position to a lateral and medial to...

PONTOS DE BLOQUEIO DOS NERVOS METACARPIAIS PALMARES LATERAL E MEDIAL EM EQUINOS SEM RAÇA DEFINIDA

Os problemas locomotores são a queixa principal nas consultas veterinárias dentro da equideocultura, sendo que a articulação metacarpofalângica aparece com o maior índice de lesões. O bloqueio anestésico local no diagnóstico de claudicação, além de favorecer o início da terapêutica e aliviar a dor dos pacientes, permite a identificação da origem e região específica afetada, contudo, se realizada de forma incorreta (por volume inadequado de anestésico e/ou localização errônea do nervo por falta de referenciais anatômicos) pode causar inflamação, infecção e até necrose tecidual. Objetivou-se descrever anatomicamente os nervos metacarpais palmares lateral e medial de equinos, para aperfeiçoamento da técnica de bloqueio anestésico diagnóstico de quatro pontos da articulação metacarpofalângica da espécie. Foram utilizadas 20 mãos de 10 equinos adultos sem raça definida, fixadas em formaldeído a 10% e com sistema arterial marcado por solução aquosa de látex corada em vermelho. As estruturas foram identificadas mediante dissecação e suas denominações basearam-se na Nomina Anatômica Veterinária (N.A.V.). O estudo foi aprovado pelo Comitê de Ética no Uso de Animais do Centro Universitário de Patos de Minas, protocolo n° 18/17. Os nervos metacarpais palmares lateral e medial foram observados em todos os espécimes com origem no ramo profundo do nervo palmar lateral, imediatamente distal à articulação intercárpica. Após sua origem, o primeiro nervo estendeu-se ipsilateralmente a partir do tronco comum, enquanto que o segundo posicionou-se de forma contralateral, após cruzar superficialmente o músculo interósseo. Ambos penetraram ao nível do terço médio entre o músculo citado e o osso metacárpico III e, respectivamente, assumiram paralelamente uma posição medial ao osso metacárpico IV e lateral ao metacárpico II. Distalmente, estes nervos emergiram de uma posição palmar para lateral e medial ao nível da extremidade distal dos ossos metacárpicos correspondentes e adjacentes ao recesso palmar da articulação metacarpofalângica, onde por fim, ramificaram-se. Os nervos metacarpais palmares lateral e medial apresentaram origem e disposição semelhantes ao já descrito, entretanto, apesar de bastante citados na literatura, destacamos aqui conforme recomendado pela N.A.V., a não utilização dos termos axial e abaxial como indicativos de posição e direção para equinos. Como parte do bloqueio anestésico diagnóstico de quatro pontos da articulação metacarpofalângica, indica-se para a dessensibilização dos nervos estudados, sejam palpadas as extremidades distais dos ossos metacárpicos IV e II. Após a identificação, com a utilização do polegar alojado a partir da extremidade no sentido proximal, introduz-se a agulha bilateralmente por 1,5cm de forma perpendicular entre os ossos metacárpicos supracitados e o músculo interósseo, com esse último e os tendões dos músculos flexores tracionados em sentido palmar, evitando assim, traumas às estruturas próximas e aperfeiçoando a técnica utilizada.

Locomotion problems are the main complaints at veterinarian practices within equine breeding management, once metacarpophalangeal articulation comes out reaching the highest rates of lesions. Local anesthesia blockage at claudication diagnosis besides favoring the beginning of the therapy and relieving patients pain, it allows the identification of the specific affected region and its origin, however, if it is done incorrectly (by improper volume of anesthetics application and/or mistakenly nerve identification due to the lack of anatomic referential) it may cause inflammation, infection or even tissue necrosis. The aim was describing anatomically lateral and medial palmar metacarpal nerves in horses, to improve diagnostic anesthetic block techniques on four metacarpophalangeal articulation joints of the specie. A number of 20 foots from 10 horses of unidentified breed were used to be fixated in 10% phormaldehyde and with a marked arterial system by water solution of red dyed latex. The structures were identified by dissection, and their denomination bases on Veterinary Anatomical Nomenclature (V.A.N.). This study was approves by Animal Ethical Committee of the University Center of Patos de Minas, under protocol number 18/17. Lateral and medial palmar metacarpal nerves were observed in all specimens originated from the deep branch of lateral palmar nerve, immediately distal to the intercarpal articulation. From its origin afterwards, the first nerve extended ipsilaterally from the common digital extensor tendon, while the second nerve has positioned contralaterally after crossing the interossei muscle. Both penetrated to the level of the mid third of the referred muscle and the metacarpal boné III and, assumed respectively a parallel medial position to the metacarpal bone IV and lateral to the metacarpal II. Distally, those nerves emerged from a palmar position to a lateral and medial to the distal extremity of the metacarpal bones, corresponding and adjacente to the metacarpophalangeal articulation palmar recession, where finally they ramify. The lateral and medial palmar metacarpal nerves present similar origin and disposition to the above described, however, besides largely mentioned in literature, we point out here as recommended by V.A.N., no use of terms like axial and abaxial as position indicators for equine. As a part of block anesthetic diagnosis of four metacarpophalangeal articulation points, it is hereby indicated for the studied nerves desensitization, should be palpated the distal extremities of the metacarpal bones IV and II. After the identification, using thumb located from the extremity at proximal direction way, introduce the needle bilaterally for 1.5cm downright between the above mentioned metacarpal bones and the interossei muscle, being these latter and the flexor muscle tendons drawn in the palmar direction, therefore avoiding traumas in the structures nearby and improving the applied technique.