The Thomas splint, with traction by means of a simple Spanish windlass mechanism, affords a simple, efficient, and economical method of treatment for fracture of the humerus. There is occasionally, however, the disadvantage of too great a localized pressure against the chest wall with accompanying pain and skin necrosis. This disadvantage may be overcome by the application of a plaster-of-Paris buttress (which is a modified jacket), allowing for the diffuse distribution of pressure of the ring of the Thomas splint and the resultant relief of pain.