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- PATIENTS AND METHODS
Pain, stiffness, and joint deformity may cause a serious decrease in hand function for people with rheumatoid arthritis (RA). Characteristic finger deformities in RA are swan neck deformity, boutonnière deformity, and ulnar deviation and subluxation of metacarpophalangeal joints. Surgical correction of deformities (if necessary with implantation of joint prostheses) may yield significant improvement, especially regarding pain, realignment, and aesthetics (1–3). Range of motion is less influenced, and little is known about the effects of hand surgery on objective, quantifiable measures of hand function (4).
In some cases, finger orthoses may be a good alternative to surgery. One example of finger orthoses is the Silver Ring Splint (SRS), which was developed in 1985. SRSs are combinations of oval rings made of high-quality sterling silver. This material combines adequate strength and rigidity with an acceptable cosmetic appearance. SRSs are easy to clean, can be used in warm water, and rarely cause any skin allergy. In a comparative study, SRSs rendered equal functional results to thermoplastic orthoses, whereas they were valued better on aspects of comfort and cosmetics (5). However, to our best knowledge no data have been published on the effect of SRSs on hand function in RA patients. We would expect dexterity and other aspects of hand function to improve, but this remains to be proven. In one study, for example, wrist braces unexpectedly appeared to cause impaired instead of improved hand function (6). Therefore we decided to study the effect of SRSs on hand function in RA patients over a 1-year period.
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- PATIENTS AND METHODS
Of 29 patients who were asked to participate, 19 (66%) gave informed consent and 17 (59%) were eligible for the use of 1 or more SRS (14 women, 3 men; median age 65 years, range 37–74 years; median disease duration 21 years, range 3–41 years). All but 1 were right handed. At the time of the study, 14 patients (82%) used nonsteroidal antiinflammatory drugs, 14 (82%) were taking a stable dose of DMARD (7 methotrexate, 2 azathioprine, 2 hydroxychloroquine, 1 aurothioglucose, 1 D-penicillamine, 1 sulfasalazine), and 7 (41%) were taking a maintenance dose of 5–10 mg prednisolone. Medication did not change during the trial period.
These 17 patients were supplied with a total of 72 SRSs: 64 for proximal interphalangeal (PIP) joints, 5 for distal interphalangeal joints, and 3 for first interphalangeal joints (Table 1). Most patients received splints for both hands. In 4 patients (24%), it proved impossible to provide satisfactory SRSs for 1 or more fingers. In patient P, SRSs caused paraesthesiae in the fingertips. In patient Q, rheumatoid nodules developed on the PIP joints, which prevented the SRSs from passing the joints. These 2 patients could not tolerate their SRSs and dropped out of the study. They had low SODA and maximum AIMS2 scores at baseline, indicating poor dexterity. Patient P had a high DAS28 score at baseline but not at T2. Patient G experienced unpleasant pressure on bony joint edges and eventually used only 1 of her 6 SRSs. Patient H found the SRSs uncomfortable but gave no particular reason. In 6 other patients, minor modifications were necessary during the study. Of the original 72 SRSs, a total of 24 (33%) were discarded during the course of the year. The main reasons for discard were paraesthesiae (8 SRSs in patient P) and pressure from bony edges or rheumatoid nodules (6 SRSs in patients G and Q). In all cases, the patients themselves decided not to wear the splints.
Table 1. Overview of all SRSs studied, average time of use during the first month, modifications, and reasons for failure*
|Patient||Left hand||Right hand||Hours per day||Modification, problem, or reason for failure|
|A|| ||D||D||P||I|| || || ||D|| ||12||Buddy splint R-3-4-5 added afterward|
|B||P||P||P||P|| || ||P||P||P|| ||5.5|| |
|C|| || ||P||P|| || || || || || ||6||Uncomfortable while driving a car|
|D|| || ||P||P||I|| || ||P||P||P||13|| |
|E|| ||P||P|| || || ||P|| || ||PX||5|| |
|F|| || ||P||P|| || ||P||P|| ||P||14|| |
|G|| || ||PX|| || ||IX||PX||P||DX||PX||6||Pressure on bony joint edges, R1 broken|
|H|| ||PX||PX|| || || || ||PX||PX|| ||?||Unsatisfactory, no specific reason given|
|I|| || || || || || ||P|| || || ||11|| |
|J|| ||PX|| || || || || || ||P|| ||10||Poor fit despite adjustments|
|K|| ||DX|| || || || ||P||P|| || ||14||L4 kept slipping off the finger|
|L||P||P||P|| || || || ||P|| || ||?||Buddy splint R-4-5 added afterward|
|M||P||PX||PX||P|| || || || || || ||9.5||Lack of space between fingers|
|N||P|| || || || || ||P||P||P|| ||8|| |
|O||P||P|| ||P|| || ||P|| || ||P||8||L2 lost and replaced|
|P||PX||PX||PX||PX|| || ||PX||PX||PX||PX||13.5||Paraesthesiae in all fingers, dropped out|
|Q|| || || || || || || ||PX||PX|| ||14||Growing rheumatoid nodules, dropped out|
Individual results on dexterity, disease activity, and patient satisfaction are shown in Table 2. Group results of the 15 patients who completed the study are shown in Table 3. During followup, SODA scores improved by a mean of 9 points. At T2 and T3, the difference from baseline was statistically significant for patients still wearing their SRSs (Wilcoxon's signed rank test P = 0.005 and P = 0.026, respectively). SODA-pain showed no significant change, nor did grip or pinch strength. The Dutch AIMS2 hand and finger function subscale improved slightly after 1 month, (median 6.0 at baseline and 4.5 at 1 month on a 0–10 scale), but at T2 and T3 this improvement was not statistically significant.
Table 2. Individuals' results of SODA, AIMS2, DAS28 and patient satisfaction*
|Patient||SODA||AIMS2||DAS28||Wished to continue†||Wanted earlier‡|
|P||38||−12|| || ||10.0||−1.5|| || ||7.4||−4.2|| || || |
|Q||59||22||9|| ||10.0||−1.0||−1.5|| ||4.6||−0.5|| || || |
Table 3. Results of hand function, grip strength, and disease activity for patients who completed the study (n = 15)*
| ||T0 (no SRS)||T1 (1 month)||T2 (3 months)||T3 (12 months)|
|SODA||71 (24–98)||79 (31–97)||81 (29–103)†||85 (46–100)‡|
|SODA change from baseline|| ||5 (−10–16)||6 (−4–19)||5 (−4–36)|
|SODA pain||3 (0–10)||3 (0–10)||2 (0–9)||4 (0–10)|
|Dutch AIMS2 hand and finger function||6.0 (0.5–8.5)||4.5 (0.5–10.0)||5.0 (0.0–10.0)||5.5 (0.5–9.5)|
|Grip strength, mm Hg§||96 (65–173)||96 (68–164)||85 (64–159)||95 (54–165)|
|Pinch grip, kg (15 hands)¶||8.5 (3.0–15.5)||8.0 (3.0–16.5)||9.0 (4.0–14.0)||8.0 (3.0–18.0)|
|DAS28||4.9 (1.8–6.5)|| ||5.1 (1.8–5.9)||4.4 (1.7–6.2)|
There was a statistically significant change in DAS28 at T3 (–0.5; P = 0.019), but only patient C showed a clinically relevant 1.2-point improvement at that time. None had significantly increased disease activity.
Fifteen patients completed the study and answered the questionnaire after 1 year. On a scale of 1–5, they scored a mean of 3 (indifferent) for overall satisfaction, comfort, pain, cosmetics, and effect on hand function. Eleven patients said they would continue to wear their SRSs, 2 expected not to wear them anymore, whereas 2 did not know. Six patients stated they would have liked to have had the SRSs much sooner.
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- PATIENTS AND METHODS
Although most of our patients had severe longstanding hand deformities, we found that observed dexterity improved with a mean change of 9 points. In 7 patients, SODA scores improved by 9 points or more, which is considered a relatively good change (11). After hand surgery in RA patients, a mean improvement of 4.4 points was found (12), with largest improvement after metacarpophalangeal implant arthroplasty (8.7 points) and arthrodesis of fingers or thumb (10.0 points). In a 1-year observational study of 94 RA patients with a mean disease duration of 13 years, the SODA score decreased by a mean of 6 points (13). Compared with these data, the 9-point improvement after 1 year in our study may be considered quite remarkable.
Self-reported hand function (AIMS2) improved from 6.0 at baseline to 4.5 and 5.0 at T1 and T2, but this did not reach statistical significance, possibly due to the small study sample or a lack of sensitivity to change in the outcome measure. In the SODA, patients are asked to perform tasks in a specific manner, whereas in everyday life they may have adjusted to alternative ways of performing these tasks. Thus there may be a discrepancy between impairment as experienced by the patient and dexterity as observed by the occupational therapist. The mean DAS28 improved by 0.5 points during the study period, but this is unlikely to explain the SODA change. It has been shown that only 10% of the variation in the SODA score is related to disease activity (6).
Grip strength did not improve, which is hardly surprising considering the longstanding disease and the extent of hand deformities. Accurate pinch grip measurement was difficult in some patients due to extensive deformities or because the plain SRSs slipped from the metal surface of the pinch gauge. In future research, other methods may be considered to measure strength in separate fingers.
Most of our subjects received SRSs for both hands, so we could not examine if the effect of SRSs on dexterity is influenced by handedness. Limitations of this pilot study are its small sample size and the use of single observers.
Despite all efforts to make the splints fit as well as possible, 33% of SRSs were eventually considered failures. There are several explanations for this result. First, most of our patients had longstanding finger deformities, sometimes requiring large forces from SRSs to correct them, causing skin damage, pain, and paraesthesiae. Therefore, in our opinion SRSs can best be applied during the earlier stages of deformity, when correction is still relatively easy and progression of deformities may be prevented or slowed. However, it may be difficult to convince patients of the benefits of wearing SRSs when they have only minor deformities that do not cause much impairment.
Thickening of finger joints was a second problem. If the proximal ring of an SRS is large enough to pass a thickened joint, it is often too wide to fit properly on the proximal phalanx. Currently, this problem can be solved by using an SRS with a hinged proximal ring, but at the time of our study this construction was not yet available.
In our study, SRSs were ordered from the manufacturer according to standard shapes and sizes. If an SRS did not fit properly, the importer and the occupational therapist could make only small adjustments, or a new SRS had to be ordered. This procedure is unsatisfactory in complicated cases, in which we would prefer the patient to be assessed in the presence of the manufacturing silversmith, to work out the optimal solution to individual problems.
Finally, in this study all those finger deformities were treated for which the therapists believed SRSs to be a feasible solution. Had we focused on deformities that needed treatment from the patients' point of view, their motivation and satisfaction might have been better.
In conclusion, this pilot study shows that SRSs can significantly improve dexterity, even in patients with longstanding RA and severe hand deformities. SRSs may prove to be a simple, noninvasive, and relatively inexpensive alternative for hand surgery. Careful patient assessment by an occupational therapist in consultation with the treating physician, as well as correct timing and well-fitting splints, are necessary conditions for a satisfactory result.