Clinical Effectiveness of Botulinum Toxin Type B in the Treatment of Subacromial Bursitis or Shoulder Impingement Syndrome

Objectives: Subacromial steroid injections are used as a treatment method in subacromial bursitis (SB) or shoulder impingement syndrome (SIS). However, the steroid effect is relatively restricted to the short-term and repeated injections are frequently required, which contributes to unwanted side effects. As an alternative, botulinum toxin (BT) has recently been used for pain relief. This study aimed to investigate the clinical effectiveness of BT type B and to compare this with the effectiveness of steroids. Methods: Sixty-one patients diagnosed with SB or SIS were divided into 2 groups and treated with BT type B (BT group) and trimacinolone injection (TA group) under ultrasound guidance, respectively. Numeric Rating Scale (NRS), active shoulder abduction angle, and the Korean version of the score on the Disability of Arm, Shoulder, and Hand (DASH) were measured before the treatment, and at 1 and 3 months after the treatment. Results: Both groups obtained a significant improvment of NRS, DASH, and active shoulder abduction at 1 and 3 months follow-up. BT group showed significantly better outcomes in terms of reduction of NRS and DASH at 3 months than TA group. BT group showed strong trend toward the larger degree of active shoulder abduction than the TA group at 3 months follow-up, as well. Whereas, no significant difference was found in NRS, DASH, and active shoulder abduction between the 2 groups at 1 month follow-up. Discussion: BT type B can be a useful strategy and has great potential for replacing steroids as a treatment for SB or SIS.