Usability of thenar eminence orthoses: report of a comparative study

Objective: To determine the difference in the usability of three types of t henar eminence (TE) orthoses. Design: Prospective comparative pre-experimental study with randomized cros s-over design. Setting: Rehabilitation centre. Subjects: Ten patients with osteoarthritis of the carpometacarpal I joint c onfirmed by X-ray. Intervention: Three types of TE orthoses, made of either supple elastic mat erial, elastic material with a semi-rigid thumb busk or a semi-rigid (polye thylene) material. Main outcome measurements: Pain at the thenar eminence, pinch force, hand f unction, cosmesis, comfort and function of the TE orthosis. Results: The supple elastic TE orthosis scores significantly better than th e more rigid types on the subjects 'comfort', 'function' and the Green Test , while the semi-rigid orthosis scores best on 'cosmesis'. The score on the subject 'pain reduction' shows no significant difference between the three types of TE orthoses. The scores obtained correspond with the outcome of s tructured interviews about the usability of the TE orthoses. Conclusion: Eight out of 10 patients prefer the permanent use of a TE ortho sis. Six patients chose the supple elastic orthosis and two chose the semi- rigid orthosis.