Collagenase is an enzyme that breaks down collagen, which is a key component of connective tissue, such as fascia. XIAFLEX is an FDA-Approved collagenase for treatment of Dupuytren's contracture with a palpable cord in the fingers, and Peyronie's disease in the penile tissue. In this research project, we plan to use collagenase to treat spasticity in patients with neurological impairments, such as stroke, brain injury, and spinal cord injury. FDA guidelines will be followed for dosing and patient selection to minimize or reduce the risks.

The Modified Ashworth Scale (MAS) evaluates the increase in muscle tone associated with upper motor neuron lesions. MAS scores will be recorded for the target muscle group(s) at each assessment time point.Scores range from 0 to 4, with an additional grade of 1+ between 1 and 2. Scores are defined as: 0 = no increase in muscle tone; 1 = slight increase in muscle tone with a catch and release or minimal resistance at the end of the range of motion; 1+ = slight increase in muscle tone with a catch followed by minimal resistance through less than half of the range of motion; 2 = more marked increase in muscle tone through most of the range of motion, but the affected part is easily moved; 3 = considerable increase in muscle tone, passive movement difficult; 4 = affected part rigid in flexion or extension.Lower MAS scores indicate reduced spasticity and improved muscle tone, whereas higher scores indicate greater spasticity.

Adverse events include

1. Serious complications of XIAFLEX injection include tendon rupture, serious ligament damage, or skin laceration that may result in the inability to fully bend the joint and may require surgery to correct the complication.
2. XIAFLEX injection is likely to result in swelling, bruising, bleeding, and/or pain of the injected site and surrounding tissue.

Range of motion (ROM) refers to the degree of movement available at a joint, measured in degrees using a goniometer. For PROM, the examiner will move the joint to its maximal pain-free range. Measurements will be recorded in degrees, and higher values indicate greater joint mobility.