Latarjet procedure for shoulder instability: Implications in the innervation of the subscapularis muscle

Our aim was to describe whether Latarjet's technique affects subscapularis muscle innervation.

We studied 12 embalmed shoulders. Subscapularis muscle innervation pattern was registered. Dimensions of the subscapularis at the glenohumeral joint line and the nerves entry point were measured. Horizontal distances from the nerves to the glenohumeral joint line as well as vertical ones to the split were measured before and after Latarjet procedure. A safe zone for the split was designed to avoid damage to subscapularis innervation.

Subscapularis muscle is innervated by three principal branches: upper, middle, and inferior subscapularis nerves. No statistical differences were found between innervation distances before and after Latarjet procedure. To perform subscapularis split along the muscle safe zone, two thirds' proportions throughout all the split must be maintained.

Subscapularis muscle has a triple innervation and was not altered after Latarjet procedure. Therefore, Latarjet technique seems to respect subscapularis muscle innervation if its split is placed through the subscapularis muscle safe zone.