# Neurological Anatomy Applied to the Deltopectoral Surgical Approach: Safety Parameters in the Latarjet Procedure

## TL;DR

This study identifies safe distances to nerves during a specific surgical approach for the Latarjet procedure, helping surgeons avoid nerve damage.

## Contribution

The study provides new anatomical safety parameters for the deltopectoral approach in the Latarjet procedure using cadaver dissections.

## Key findings

- The distances from the medial glenoid rim to various nerves were measured in neutral and external rotation.
- The deltopectoral approach is safe, but caution is needed near the subscapularis muscle and coracoid graft fixation.
- Measured distances to the axillary, musculocutaneous, and subscapular nerves were consistently small.

## Abstract

Objective
 The present study aims to identify neurological safety parameters for performing the Latarjet procedure via the deltopectoral approach in a cross-sectional and prospective analysis of fresh cadavers.

Methods
 We dissected 12 shoulders from cadavers in good condition with no history of previous surgery or musculoskeletal dysfunction. Their mean age, height, weight, and body mass index (BMI) were the following: 75.33 (41–97) years, 168.81 (149–186) cm, 60.35 (26–77) kg, and 21.38 (11.71–34.22) kg/m
2
, respectively. We identified the anatomical landmark of the deltopectoral approach (medial glenoid rim, MGR) and measured its distance from the axillary, musculocutaneous, and subscapular nerves.

Results
 We obtained the following measurements in neutral rotation and 40° external rotation, respectively: distance from the MGR to the axillary nerve (AN), 2.87 cm and 2.58 cm (
p
 = 0.29); distance from the MGR to the musculocutaneous nerve (MCN), 2.70 cm and 2.54 cm (
p
 = 0.36); distance from the MGR to the upper subscapular nerve (USSN), 3.83 cm and 4.00 cm (
p
 = 0.30); distance from the MGR to the middle subscapular nerve (MSSN), 3.50 cm and 3.50 cm (
p
 = 1.00); and distance from the MGR to the lower subscapular nerve (LSSN), 3.00 cm and 2.83 cm (
p
 = 0.36).

Conclusion
 The deltopectoral approach is safe. However, in the Latarjet procedure, subscapularis muscle splitting and coracoid graft fixation require attention and caution due to the small distance to the adjacent nerves. These precautions can avoid major postoperative complications.

Objetivo
 Identificar parâmetros de segurança neurológica para a realização do procedimento de Latarjet através da via deltopeitoral por meio de um estudo transversal e prospectivo em cadáveres frescos.

Métodos
 Foram dissecados 12 ombros de cadáveres, sem história de cirurgia ou disfunção musculoesquelética prévia e em bom estado de conservação, com médias de idade, altura, peso e índice de massa corporal (IMC): 75,33 (41–97) anos; 168,81 (149–186) cm; 60,35 (26–77) kg e 21,38 (11,71–34,22) kg/m
2
, respectivamente. Foi identificado o marco anatômico da via estudada (rebordo medial da glenoide - RMG) e sua distância para os nervos axilar, musculocutâneo e subescapular foi mensurada.

Resultados
 Obtivemos as seguintes medidas em rotação neutra e rotação externa de 40°, respectivamente: a distância entre o RMG e o nervo axilar (NA) = 2,87 cm e 2,58 cm (
p
 = 0,29); a distância do RMG ao nervo musculocutâneo (NMC) = 2,70 cm e 2,54 cm (
p
 = 0,36); a distância do RMG ao nervo subescapular superior (NSS) = 3,83 cm e 4,00 cm (
p
 = 0,30); a distância do RMG ao nervo subescapular médio (NSM) = 3,50 cm e 3,50 cm (
p
 = 1,00); e a distância do RMG ao nervo subescapular inferior (NSI) = 3,00 e 2,83 cm (
p
 = 0,36).

Conclusão
 A via deltopeitoral é considerada segura; porém, é preciso atenção e cautela durante o
split
do músculo subescapular e na fixação do enxerto do coracoide no procedimento de Latarjet, devido à curta distância até os nervos adjacentes. Tais precauções podem evitar maiores complicações pós-operatórias.