April, 2016: Is “dynamic” better than static splinting for De Quervain tendinitis?
Investigators in Iran just published a prospective, unblinded 2-week study of comparing a conventional thermoplastic long thumb spica splinting to a hinged thermoplastic thumb spica orthosis that allowed for wrist extension/flexion but prevented radial/ulnar deviation.
MATERIALS AND METHODS: They divided 24 women with acute De Quervain syndrome into two groups. All patients were between 18 and 60 years old and had not had injections in the past 3 months. At intake and after 2 weeks of treatment, the investigators measured tip and key pinch strengths and collected DASH scores and 100-point visual analog scale (VAS) scores measuring satisfaction.
The conventional orthosis consisted of one piece of thermoplastic that was custom-molded to each subject from thumb interphalangeal joint to mid forearm with the thumb held in radial abduction. The dynamic orthosis was overall the same shape and length but consisted of two pieces of thermoplastic articulated at the radial styloid such that it allowed wrist E/F but prevented R/U deviation. All subjects were asked to wear their orthosis at least 6 hours a day.
RESULTS: The pretreatment ages, BMIs, strength measurements, and DASH scores were statistically equal for both groups. After 2 weeks, both groups showed increased strength and function and decreased pain compared to pre-treatment, but these results were statistically identical between the groups.
After 2 weeks, the VAS average satisfaction scores were 64+/-4 for the conventionally splinted group and 50+/-4 for the group using the articulated orthosis. This difference was significantly different P .005.
COMMENTS: First, I take exception to the authors describing the articulated orthosis as dynamic. To me, a dynamic orthosis moves by itself, powered by springs or rubber bands. They rightfully acknowledge that a rigid long thumb spica orthosis for De Quervain syndrome is awkward and uncomfortable. My patients who have tried one usually discard it after several minutes because it is too restrictive for performing even simple daily activities.
Second, the authors did not ask about compliance. Did the subjects actually were the appliances 6 hours a day as requested? I have my doubts. Then, even though the satisfaction scores were statistically different for the two groups, is a 14 point change on a 100 point scale a meaningful clinical difference?
The study would have been strengthened had they followed the subjects for several longer intervals, either with continued bracing or after completion of the bracing period.
Finally, to make such a study clinically meaningful for me, the investigators would have had to compare bracing with cortisone injection, which is highly effective and does not require any immobilization of the wrist or thumb. Bracing could conceivably be indicated in somebody who was entirely needle phobic or who could not receive cortisone injections. In that case, the hinged orthosis might prove to be better tolerated than a conventional thermoplastic thumb spica orthosis.