Soft spot: the important zone at the standard posterior portal of shoulder arthroscopy

Abstract

Background/aim: The localization of the standard posterior portal of shoulder arthroscopy and landmarks mentioned in the literature are unclear. The purpose of this prospective cadaveric study was to determine the localization of the standard posterior portal and its distance to the neural structures. Materials and methods:One fresh frozen and 10 formalin-fixed adult cadaveric shoulders were dissected. In the beach chair position, a 5-mm trocar was placed anteroposteriorly from the superior edge of the subscapularis muscle, superior to the tip of the coracoid process and tangent to the glenoid. The relevant distances of the posterior exit point were measured.Results: In all specimens, the exit point was a triangular fibrous area, between the posterior and lateral parts of the deltoid. Medial and inferior distances of the trocar to the posterolateral tip of the acromion were 1.88 ± 0.53 cm and 1.35 ± 0.34 cm and distances to the axillary and suprascapular nerves were 4.54 ± 1.08 cm and 2.54 ± 0.85 cm, respectively. Conclusion:The most important finding of this study was the superficial localization of the soft spot between the posterior and lateral parts of deltoid.

Experience of endoscopic transcapsular axillary nerve decompression: а series of clinical cases

“…Использовали стандартную 30° оптику и стандартное оборудование для артроскопии крупных суставов. Доступ в полость сустава начинали с установки стандартного заднего порта в области «мягкой точки» [13]. Производили диагностическую артроскопию плечевого сустава с оценкой внутрисуставных структур (рис.…”

Determining the accurate placement of a posterior portal in shoulder arthroscopy with the use of computerized tomography images

“…Little research has been performed assessing the best site for portal placement. Most research is based on small volume cadaveric studies, anecdotal evidence and surgeon preference [2][3][4][5][6]8 .…”

“…There are many portal placement options described in the literature [2][3][4][8][9] , but the posterior portal is the most commonly described. The posterior portal is traditionally introduced at a point relative to the posterior corner of the acromion (PCA) through J o u r n a l P r e -p r o o f an area referred to as the "soft spot" which has now been identified as a triangular fibrocartilaginous area between the deltoid heads 6 . More recent research has shown that using the PCA as a reference point has its own limitations due to the variability of the anatomy in this region 5,6 , yet is still remains the standard of care across many institutions.…”

“…The posterior portal is traditionally introduced at a point relative to the posterior corner of the acromion (PCA) through J o u r n a l P r e -p r o o f an area referred to as the "soft spot" which has now been identified as a triangular fibrocartilaginous area between the deltoid heads 6 . More recent research has shown that using the PCA as a reference point has its own limitations due to the variability of the anatomy in this region 5,6 , yet is still remains the standard of care across many institutions. Furthermore the actual location of this "soft spot" varies from anywhere between 1-2 cm medial to and 2-3 cm inferior to the posterolateral corner of the acromion (PCA) 12,13 .…”

“…Most research is based on small volume cadaveric studies, anecdotal evidence, and surgeon preference. 2 , 3 , 4 , 5 , 6 , 8 …”