A summary of results from a prospective post-market observational study for the treatment of osteoarthritis of the thumb  using Actimove® Rhizo Forte thumb orthosis
Osteoarthritis (OA) of the thumb is one of the most frequently occurring degenerative diseases of the hand and occurs most often in women aged between 50 and 60 years . Initially, OA of the thumb manifests as movement and stress-related pain in the thumb joint, which can be further accompanied by morning stiffness, movement restriction, and loss of strength, as well as swelling of the thumb base. OA of the thumb can lead to the complete loss of joint function, if not adequately treated.
OA of the thumb is most often initially treated by the application of conservative non-surgical care, such as cooling and the intake or local application of anti-inflammatory medication. Primary therapy also comprises avoiding activities, and the application of a thumb orthosis during the night time and/or daily for immobilisation of the saddle joint. Especially in the early stages of the OA of the thumb, the wearing of an orthosis over several weeks can lead to a significant pain reduction, but even patients with severe forms of OA of the thumb may profit from a splinting system.
The Actimove Rhizo Forte thumb orthosis is a novel orthosis for the treatment of painful OA of the thumb of the saddle joint. The shape of the orthosis allows free movement of the adjacent hand and finger joints, while enabling secure immobilisation of the saddle joint. Due to the integrated aluminium core, the orthosis can be individually adjusted to different hand shapes.
Subsequent to the development of the orthosis, a prospective, open observational study was performed in three orthopaedic study centres in Germany. The aim of the study was to evaluate the product, particularly with regard to the fit of the orthosis, wearing comfort and suitability for daily use, as well as the medical parameters’ effectiveness and safety under the conditions of routine practice in a standardised way.
Patients: Between December 2014 and April 2015, 28 patients (78.6 per cent females, 59.5 ± 10.7 years on average) with a radiologically confirmed diagnosis of OA of the thumb were involved in the study.
Treatment: The application of the Actimove Rhizo Forte thumb orthosis followed the manufacturer’s recommendations and clinical requirements. The duration of the wearing period depended on the individual complaints and was 7 weeks on average (range 2.8 to 10 weeks) for 8 hours a day (range 4.4 to 10.5 hours). Study procedures were specified in a study protocol. At the initial and the final visit, the Actimove Rhizo Forte thumb orthosis was evaluated with regard to general requirements (handling, fit, wearing comfort, opening and closing, shape system, suitability for daily use, patient satisfaction, overall evaluation) and medical requirements (occurrence of pressure points, localisation of pressure points on the palm and back of the hands, moisture, and sweating) independently by the patients and the treating specialist in orthopaedics. Parameters were assessed on a scale of 1 to 6 (1 = very good to 6 = very bad for general requirements, 1 = none to 6 = very strong for medical requirement) and pain was assessed by means of a 0-10 VAS-scale (0 = no pain to 10 = worst pain imaginable pain).
The majority of patients and treating physicians assessed the orthosis with regard to general requirements as “good“ to “very good”. Particularly handling and opening and closing of the orthosis was assessed as “very good”. Patients evaluated wearing comfort as “good“ (score value of 2) and suitability for daily use as “rather good” (score value of 2.5) after wearing the orthosis over several weeks. Overall, the patients and the treating physician were very satisfied with the orthosis (score value of 2). There were no differences between the assessments before and after treatment, except with the parameter “handling“: assessment of “handling“ increased from “good“ to “very good“ at the end of the observational study.
The results of this study with 28 patients with clinically confirmed OA of the thumb demonstrate that the use of Actimove Rhizo Forte thumb orthosis led to a considerable pain reduction through secure immobilisation. Moreover, easy handling, easy opening and closing of the orthosis and the high wearing comfort was rated highly by the patients. Sweat and heat development for longer periods of use are uncritical due to the open design and the washable material of the orthosis and were only marginally reported. Pressure points at the palms and backs of the hands were observed in a minority of patients, but, generally, cannot be fully excluded due to the specific material and type of construction of the orthosis. A reduction of pressure points could be achieved by explaining the plasticity of the orthosis material to patients, and by technical improvements of the orthosis. Therefore, the Actimove Rhizo Forte thumb orthosis has demonstrated its ability for conservative treatment of OA of the thumb and may add important value to the existing therapy options.
1) Möller J, Pfeil U, Weinhardt C, report to BSN medical 2015, data on file.
2) Ladd AL, Weiss AP, Crisco JJ, Hagert E, Wolf JM, Glickel SZ, Yao J. The thumb carpometacarpal joint: anatomy, hormones, and biomechanics. Instr Course Lect. 2013;62:165-79.