Description

Regional anaesthesia is often favoured for shoulder surgery as it could effectively provide anaesthesia and postoperative analgesia. Additionally, the upper limb has multiple nerve targets that can be blocked. Innervation of shoulder joint is complex with 70 % contribution from suprascapular nerve (SSN), remaining from axillary (AN), lateral pectoral, subscapular, and musculocutaneous nerves. Therefore, Effective postoperative analgesia for shoulder surgery should target mainly both the SSN and AN which can be performed either at the level of the nerves themselves or their more proximal origins, often within the brachial plexus.

Until recently, interscalene brachial plexus block (ISB) was considered the gold standard technique for intra- and postoperative pain management in shoulder surgeries. However, its safety was questioned due to its drawbacks including prolonged motor block, and most importantly hemidiaphragm paralysis and the resultant pulmonary function compromise with prolongation of the patients' recovery time. The shoulder block which refers to the combined suprascapular nerve and axillary nerve block (SSNB-ANB) was first described in 2007 as an alternative to interscalene block (ISB) for shoulder surgeries with several studies reporting equipotent pain relief and patient satisfaction when the combined SSNB -ANB compared with the ISB alone with fewer complications due to the location of injection.

In 2020, Galluccio et al. described a novel ultrasound-guided block, the shoulder anterior capsular block (SHAC), motor sparing block, which blocks all the nerves supplying the shoulder based on the combination of two blocks targeting the interfacial and pericapsular spaces. Thanks to this approach which block axillary, subscapular, lateral pectoral and musculocutaneous nerves and avoid motor block associated with more proximal nerve blocks, thus allowing early active mobilization, physiotherapy and rehabilitation.

SHAC block was validated in chronic shoulder pain patients. hence, we hypothesized that SHAC block is effective in postoperative shoulder pain relief and early rehabilitation after ARCR which could make it an alternative to SSNB-ANB in these patients. This study will be undertaken to compare between the analgesic effect of ultrasound guided SHAC block versus combined ultrasound guided SSNB-ANB for arthroscopic rotator cuff surgery.