Continuous Interscalene Block vs Liposomal Bupivacaine After Proximal Humerus Fracture Surgery

Restricted range of motion following open reduction and internal fixation (ORIF) of proximal humerus fractures is a potential complication that severely limits functional outcomes . It must therefore be avoided by adequate pain control in order to allow for early mobilisation in addition to physiotherapy. Interscalene block (ISB) is one of the most effective and widely used regional analgesic options shoulder surgeries. ISB can be delivered as a single injection or by continuous infusion via an indwelling catheter. While continuous interscalene block (CISB) offers a longer duration of analgesia as compared to a single injection of the same anaesthetic, it carries an inherent risk of catheter malposition, dislodgement, and infection. As compared to standard bupivacaine (SB), liposomal bupivacaine (LB) is a formulation designed to prolong the duration of analgesia up to 72 hours via a single injection. While this could avoid the need for an indwelling catheter, results of studies comparing LB to CISB have been inconsistent. The purpose of this is non-inferiority trial is to compare the effectiveness of a single injection of LB versus CISB with SB on pain control following ORIF of proximal humerus fractures. The study hypothesis is that LB is not unacceptably worse than CISB with regard to pain control in the first two postoperative days. Patients providing informed consent will be screened for eligibility. All eligible patients will be randomly assigned in a double-blind manner (participant and investigator) and a 1:1 ratio to receive either LB or CISB.