Rotator cuff conditions are characterized by unspecific signs, as well as anatomic alterations and symptoms. They have a multifactorial etiology and may include everything from tendinitis to massive, full thickness tears of the rotator cuff tendon that compromise the normal biomechanics of the involved shoulder. They usually occur in people over 40 years of age but lesions resulting from trauma may vary according to the mechanism of injury and are not directly related with the age at onset of symptoms. Vascular factors have been described as related with rotator cuff tendon damage in conditions affecting the microcirculation. However, recent studies have not proven that the tendon under direct observation shows hypovascularity. Type A botulinum toxin acts by blocking the release of acetylcholine in the neuromuscular plate; in the joints it releases capsular tension and reduces proinflammatory factors such as interleukin-1 (IL-1). There are only a few papers on its intraarticular benefit; in muscle and tendon groups it not only has a muscle relaxant effect, but several publications support its utility for pain management. It has been widely used in the rehabilitation of this group of patients at low doses. Material and methods: Prospective, investigational and longitudinal study involving the follow-up of 24 patients with a diagnosis of painful shoulder syndrome proven clinically and with imaging tests, and caused by rotator cuff lesions. The patients either did not meet the criteria for immediate surgical repair or had already undergone such a repair. Type A botulinum toxin was applied to 12 patients in the subacromial space around the rotator cuff conjoint tendon, as well as in the painful spots and in the muscle contracture in the shoulder. The total dose of Type A botulinum toxin was 200 IU. The control group, also composed of 12 patients, was given a COX-2 oral antiinflammatory agent for 6 weeks (Celecoxib, 100 mg BID). Both groups followed a pre-established rehabilitation program for a total of 6 weeks and were supervised every 2 weeks. Subjective and objective assessments were made including pain, performance level and possible mobility, using Constant's functional shoulder assessment and the visual analog scale (VAS).
Results: Celecoxib group: Mean initial Constant scale score was 60; after the first dose it remained unchanged. After 2 weeks of treatment with Celecoxib the mean Constant score was 66; by 6 weeks it was 70.33, with p > 0.005. The botulinum toxin group received a maximum dose of 200 IU in the affected shoulder, 50 IU were administered subacromially and 150 in the painful spots. This treatment was combined with rehabilitation exercises supervised at the doc tor's office. The mean initial Constant scale score was 58; immediately after the first dose it went up to 70.83. Two weeks after the injection and the supervision of rehabilitation exercises at the office, the mean Constant scale score was 77.16; at six weeks it was 78.5, with p < 0.005 (p = 0.00045). The VAS in the Celecoxib group decreased at six weeks with p < 0.005.