Orthoses For Rheumatoid Fingers
Richard D. Koch, C.O. *
David A. Bird, A.B., C.O. *
The boutonniere deformity of the finger (Fig. 1 ), prevalent with rheumatoid arthritis, is characterized by flexion tightness of the proximal interphalangeal (P.I.P.) joint and hypertension of the distal interphalangeal (D.I.P.) joint, and can usually be helped by application of orthoses. The figuratively opposite deformity, the swan neck (Fig. 2 ), also can usually be helped. This paper will limit its scope primarily to the fitting of orthoses for these two deformities, along with some considerations for a thumb orthosis.
Why do these deformities need orthotic treatment? In some cases they don't, because they simply cannot be corrected (Fig. 3 ). But many cases can be corrected, and skeletal re-alignment provided by an orthosis allows much relief from pain, reduces edema, and provides a deterrent to further deformity, another advantage for the patient is greater use of the finger through stabilization, even though P.I.P. flexion is prevented when the boutonniere orthosis (Fig. 4 ) is used. Many types of orthoses, from the crude to the sophisticated, have been used for the treatment of these two deformities, including off-the-shelf items, and some of these have been successful. However, a truly successful orthosis must not only promote a deterrent to an increase in deformity, but must be cosmetically acceptable, nontoxic, and not bulky. Not many orthoses designed for these two deformities meet these standards  .
Obviously, correction will not occur when the orthosis is not worn, but many patients, no matter how severe the deformity or how great the pain, will refuse to wear a finger orthosis that is bulky and "uncosmetic".
For the patient with a severe boutonniere deformity, a dynamic reverse finger knuckle bender may be used (Fig. 5 ). for the very severe, an outrigger involving an MP stop and a P.I.P. dynamic extension unit may be appropriate (Fig. 6 ). All of these devices involve the three-point-pressure system needed to achieve stabilization and correction.
The procedure for fitting boutonniere, swan neck, and thumb orthoses that achieve correction are outlined below. These orthoses are light in weight and are accepted from a cosmetic standpoint.
Fitting the Boutonniere Orthosis
The fitting of orthoses for the fingers involves the same care and procedure common to all orthoses for the trunk, cervical spine, lower and upper limbs. The three-point-pressure system is utilized, care being taken to provide the proper contours and avoid undue pressure over the fingers and hand.
To reduce a boutonniere deformity, the boutonniere reduction orthosis (Fig. 7 ) is fitted with the volar proximal band 1/8-in. distal to the web space. The distal volar band is placed at the D.I.P. joint and the dorsal band is located over the P.I.P. joint so as to apply pressure on the dorsal surface. The orthosis should be contoured so that pressure from the distal band tends to flex the D.I.P. joint with the P.I.P. joint being held in the corrected position (Fig. 8 ).
Fitting the Swan Neck Orthosis
The swan neck orthosis is often a boutonniere orthosis rotated 180 deg, but specially designed orthoses are often used as well (Fig. 9 and Fig. 10 ). The proximal dorsal band should be 1/8-in distal to the MP joint and must not impinge on the P.I.P. joint. The distal edge of the distal dorsal band should be at the D.I.P. joint and the band must not impinge on the P.I.P. joint. The volar band should be just proximal to the P.I.P. joint so as to allow P.I.P. flexion with the orthosis while P.I.P. extension is restricted. The volar pressure applied by the distal band while P.I.P. extension is attempted encourages D.I.P. extension (Fig. 11 and Fig. 12 ).
Fitting the Thumb Orthosis
The orthosis for deformities of the IP joint in hyperextension and MP joint (Fig. 13 ) in flexion stabilizes and places the thumb in a functional position (Fig. 14 ). The orthosis is contoured to the thumb. Pressure is applied to the MP joint while the band is brought around in contour so as to apply pressure in a dorsal direction, thus causing the IP joint to flex. The band should be proximal to the IP joint but not cause impingement in the web space. The third point of pressure is the wrist strap which applies a laterally directed force.
Discussion
When treating rheumatoid arthritis with intrinsic hand deformities, it is difficult to keep it simple and at the same time provide an orthosis that is acceptable from the cosmetic standpoint.
With the boutonniere and swan neck deformities that are correctable, a reduction of pain and edema will usually follow when a well fitting, correctly designed orthosis is applied. Such an orthosis must be light, nontoxic, not bulky, and cosmetically acceptable. It must be capable of being adjusted easily without fear of breaking or deforming the orthosis. A stainless steel orthosis designed around orthotic principles not only meets these requirements but will be serviceable for many years.
A stainless steel orthosis for these two deformities is available from Camp International, Inc. The aluminum or plastic tube for swan neck correction is more difficult to adjust and with the aluminum orthosis, breakage is a factor. With a plastic orthosis bulk definitely is a problem.
For the thumb orthosis stainless steel has been found to be the best material for the reasons stated above.
Credit should be given to Ben C. Fowler, C.O., for his early work in this area.
References:
- Bennett, Robert L., "Orthotic devices to prevent deformities on the hand in rheumatoid arthritis," Arthritis and Rheumatism, 1:5, Oct. 1965.
- Cailliet, Rene, Hand Pain and Impairment, Chapter V, p. 120.
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