Pathomechanics, Gait Deviations, and Treatment of the Rheumatoid Foot

Transcription

1 Pathomechanics, Gait Deviations, and Treatment of the Rheumatoid Foot A Clinical Report PHYLLIS DIMONTE and HOLLIS LIGHT This article describes the five major foot deformities or problems often seen in patients with rheumatoid arthritis: hallux valgus, pronation of the foot, depression of the metatarsal heads, hammer or claw toes, and tendocalcaneal bursitis or subplantar spur formation. These deformities contribute to the development of common rheumatoid gait deviations such as decreased velocity, cadence, and stride length; poor heel-toe pattern; and abnormal patterns of weight bearing. Nonsurgical treatment for these problems includes joint protection methods, assistive gait devices, orthotic intervention, and physical therapy procedures. Surgical intervention provides stability for the weight-bearing joints of the foot and reduces pain. Consideration of these problems and an early intervention effort may help to prolong the ambulatory status of the patient with rheumatoid arthritis. Key Words: Gait; Rheumatoid arthritis; Foot deformities, acquired. Individuals who have rheumatoid arthritis frequently develop a combination of foot deformities unique to this disease. Although almost 90 percent of these patients are reported to have foot involvement, the literature discussing the rheumatoid foot, when compared with information about the rheumatoid hand, is rather scant. 1 In the lower extremity, weight-bearing stresses that are transmitted through the foot create the potential for injury, overuse, or strain at this site. The pathologic tissue and joint changes occurring in rheumatoid arthritis promote these problems and lead to changes in the structure of the foot. Advances in hip and knee surgery have allowed many otherwise wheelchairbound patients to remain ambulatory. In an effort to maintain the tolerance of the foot for ambulation, preventive measures may be employed to manage deformities and correct resultant gait deviations. Ms. DiMonte is Physical Therapy Consultant to the Rehabilitative Engineering Research & Development Center, Box 20, Edward Hines, Jr, Veteran Administration Hospital, Hines, IL (USA), and to the Department of Orthopaedics & Rehabilitation, Loyola University Medical Center, Maywood, IL Mrs. Light is Senior Physical Therapist and Clinical Supervisor, West Suburban Hospital, Oak Park, IL This article was submitted August 3, 1981, and accepted January 26, The purpose of this paper is to present the major deformities or problems of the rheumatoid foot and their pathomechanics, associated gait deviations, and physical examination findings. Nonsurgical and surgical treatments are also briefly outlined. DEFORMITIES AND PROBLEMS In the rheumatoid joint, there is initial involvement of the synovium with the eventual loss of joint integrity. Tendons, ligaments, cartilage, and the joint capsule are all subject to inflammation and destruction. 2 When the inflammatory process characteristic of rheumatoid arthritis affects the foot, the patient may develop painful deformities that increase stress during weight bearing. It is no wonder that many patients resort to progressively less ambulation. If treatment can be initiated to correct these deformities and provide relief, ambulation tolerance may be restored. The major foot deformities associated with rheumatoid arthritis involve the hindfoot along with the forefoot. Talonavicular joint destruction seems to occur early and results in a malalignment during weight bearing. 3, 4 In the normal gait cycle, after heel contact, the compressive forces on the subtalar (talocalcaneal) 1148 PHYSICAL THERAPY

2 Fig. 1. Major deformities in the foot affected by rheumatoid arthritis. and midtarsal joints (talonavicular and calcaneocuboid) cause the foot to become a rigid lever: the head of the talus locks into the navicular cavity, and the midtarsal joints become fixed. In the foot affected by rheumatoid arthritis, however, as the midtarsal and subtalar joints become less stable, the head of the talus shifts in a plantar and medial direction, keeping this locking mechanism from occurring. Because the normal line of weight bearing begins in the lateral heel and advances medially, the instability in the hindfoot joint allows for increased medial motion. There is increased depression of the medial longitudinal arch and outward rotation of the calcaneus, causing a valgus deformity of the heel as weight bearing occurs. The instability at the hindfoot may subsequently lead to deformity in the forefoot, specifically to hallux valgus and depression of the metatarsal heads. In hallux valgus, the metatarsophalangeal (MTP) joint of the great toe becomes inflamed, and the resultant ligamentous laxity causes instability. Lateral deviation of the proximal and distal phalanx of the great toe occurs, and it angulates toward the second toe. As a result, the flexor and extensor muscles of the great toe shift laterally and act like a bowstring. As they contract, the toe is pulled farther laterally. There is an over pull and shortening of the intrinsic muscles so that the adductors overpower the overstretched abductors, accentuating the lateral movement. The bursa located over the medial portion of the metatarsal head becomes inflamed resulting in a painful bunion. Examination of the patient will reveal a prominent, sore first metatarsal head and lateral angulation of the great toe. There may be a lateral deviation of the second through fifth toes as well. The weight-bearing capacity of the MTP joint of the great toe diminishes as the hallux valgus deformity progresses. This causes the majority of the weight to be borne by the lesser metatarsal heads. 5 The metatarsal heads are often the site of inflammation and capsular distention. With time, the collateral ligaments lose integrity, and as the patient walks, the constant stress of the toes extending leads to subluxation and eventual dislocation of the MTP joints. As the MTP joints dislocate, the proximal phalanges come to rest dorsally on the necks of the metatarsals and force the metatarsal heads downward (plantarward). This causes direct pressure on the metatarsal heads as the patient walks. The patient may complain of pain and the sensation of walking on marbles. The fat pad, located directly under the metatarsal heads, normally provides a cushion during this weight-bearing phase. With this deformity, the fat pad migrates dorsally with the proximal phalanx and therefore does not provide this protection for the metatarsal heads. Thick callouses may develop in this area. These are painful with weight bearing and may lead to ulceration. As the metatarsal heads dislocate, there is also a laxity in the MTP joints and a subsequent widening of the forefoot. This may be due to the stretching of the intermetatarsal ligaments and weakness of intrinsic muscles. As the MTP joints dislocate, the long flexor and extensor muscles of the toes lose their normally balanced position. The extensor muscles on the dorsum of the foot become shortened and the flexor muscles become stretched. The claw toe deformity occurs with hyperextension of the MTP joint and flexion of the interphalangeal joint. In hammer toe deformity, not only is the MTP joint hyperextended and the proxi- Volume 62 / Number 8, August

3 Fig. 2. Divisions of gait cycle. mal interphalangeal joint flexed, but the distal interphalangeal joint is hyperextended. As the toe flexor muscles contract at the end phase of ambulation, the hammer and claw toe deformities are exaggerated. Pressure and friction within the shoe may then cause callouses to develop on the dorsum of the toes and on their plantar tips. Finally, the patient may develop heel problems. The two areas of common involvement are at the Fig. 3. Osteokinematics of the leg, ankle, and foot during the normal gait cycle. The dots signify the division between phases of gait calcaneal insertions of the Achilles tendon and at the plantar aponeurosis. In the first situation, the bursa between the Achilles tendon and the calcaneus may become inflamed as a result of the arthritis. Further, pressure from the shoe counter may cause additional irritation and the patient will experience more pain. In the second instance, a bony spur may result from calcaneal erosion causing an irregularity at the site of the attachment of the plantar aponeurosis. Also, the rheumatoid nodules, which commonly develop on the calcaneus, may also be a source of pain to the patient. In summary, the major foot deformities and problems seen in the patient with rheumatoid arthritis (Fig. 1) are 1) pronated foot, 2) hallux valgus, 3) depression of the metatarsal heads, 4) hammer or claw toes, and 5) tendocalcaneal bursitis or subplantar spur formation. GAIT ANALYSIS AND PHYSICAL EAMINATION A brief review of normal gait is provided before consideration is given to evaluating the types of gait deviations seen in patients with rheumatoid arthritis. Recall that the major divisions of the gait cycle are the swing and the stance phase and that the stance phase may be further divided into the contact period, midstance, and propulsion (Figs. 2 and 3, Tab. 1). 5 Within each of these phases, the aspects to consider in evaluation are the osteokinematics and muscular activity occurring at the foot PHYSICAL THERAPY

4 PRACTICE Gait analysis may be performed using a variety of techniques, from complex methods using sophisticated diagnostic equipment, to simple methods using clinical observations and test results. When using these simpler methods, a few basic rules must be observed. The patient should be barefoot and the walking surface must be level. The physical therapist should note each division of the gait cycle and document the patient's compliance or deviation from the normal standard. Because involvement of the subtalar joint is believed to occur early in rheumatoid arthritis 6 and this joint's alignment affects the subsequent progression of deformities of the involved foot, analysis of this joint position is of particular importance during midstance. A method proposed by Root for this assessment is to note the direction and alignment of the curves seen on the lateral border of the lower leg proximal and distal to the lateral malleous (Fig. 4). 7 In the correctly aligned foot, the curves are in the same direction and the vertical alignment is in the same plane. In the pronated or supinated foot, the convexities are not in the same plane or direction. This malalignment can be easily observed and documented. For the patient with rheumatoid arthritis, several authors have proposed some general gait deviations not attributed to a specific anatomical deformity. 8 " 10 These deviations are decreased velocity, cadence, stride length, and range of motion of the knee as compared with matched subjects without rheumatoid arthritis. It is also possible, however, to identify specific deviations in the gait cycle caused by the progression of the rheumatoid deformities in the foot. TABLE 1 EMG Activity, a Using Wire Electrodes, of the Critical Muscles Functioning at the Foot and Ankle During Normal Gait Cycle Anterior tibialis Posterior tibialis Extensor digitorum longus Flexor digitorum brevis Abductor hallucis Lumbricals Gastrocnemius/ Soleus Contact Stance a = greater contraction than. Midstance Propulsion Swing Table 2 summarizes the gait deviations, findings on physical examination, and treatment goals. Because hindfoot instability is a component in each of the deformities, the resultant malalignment is thought to have a causative role in the other foot deformities. Though many of the resultant gait patterns are similar, the physical examination and treatment differs with each deformity. It is important therefore that each deformity be evaluated individually. Fig. 4. Posterior view of hindfoot during stance. Note alignment and direction of curves proximal and distal to the lateral malleolus. Volume 62 / Number 8, August

5 TABLE 2 Analysis of Gait Deviations, Physical Examination Findings, and Treatment Goals Pronated foot Gait Deviations Shuffled progression Decreased step length Initial contact with medial border of foot Decreased single-limb balance Prolonged double-support phase Late heel rise Plantar flexion of ipsilateral limb in swing Genu valgus with weight bearing Physical Examination Findings Tenderness over subtalar midtarsal area Limited inversion range Weak and painful posterior tibialis muscle Pronated weight-bearing posture of foot Lax medial collateral ligament of knee Treatment Goals Relieve subtalar & midtarsal joint stresses Increase ankle inversion Strengthen posterior tibialis muscle Stabilize hypermobile joints with rigid orthosis Maintain neutral alignment in stance by foot positioning Hallux valgus Metatarsophalangeal joint subluxation Lateral and posterior weight shift Late heel rise Decreased single-limb balance Diminished roll off Decreased single-limb stance Apropulsive progression Decreased single-limb balance Lateral deviation of great toe Swelling of first MTP joint Shortening of flexor hallucis brevis muscle Tenderness of great toe Weakness of great toe abduction Painful MTP heads with weight bearing Callus formation over MTP heads Ulcerations over MTP heads Limited MTP flexion Prominent MTP heads Accommodate foot with wide toe box shoe Increase extension of great toe Relieve weight-bearing stresses Redistribute pressure with metatarsal bar Relieve pressure with soft cutout shoe insert Increase flexion mobility of MTP joints Accommodate foot with extradepth shoe Hammer or Claw Toes Diminished roll off Decreased single-limb stance Apropulsive progression Decreased single-limb balance Posture of MTP joint hyperextension with proximal and distal interphalangeal joint flexion Posture of MTP and distal interphalangeal joint hyperextension with proximal interphalangeal flexion Callus formation at plantar tips and dorsum of proximal interphalangeal joint Limited MTP flexion Improve toe alignment with metatarsal bar Accommodate foot with extradepth shoe Diminish pressure with soft insert Increase toe mobility Painful Heel Toe-heel pattern No heel contact in stance Decreased stride length Decreased velocity Plantar flexion of ankle in swing Increased hip flexion in swing Decreased step length of contralateral limb Painful active plantar flexion Painful passive and active dorsiflexion Swelling and pain at Achilles insertion Tenderness over spur Decreased ankle dorsiflexion range Decrease inflammation with steroid injection or modalities Relieve weight-bearing stress Decrease pressure over spur with soft shoe insert Maintain ankle mobility Pronated Foot The specific gait deviations seen with a pronated foot occur primarily during the weight-bearing phases of gait. Pronation occurs as a combination of motions at the subtalar joint and the midtarsal joints. The mechanics of the subtalar joint allow rotatory stresses from the lower limb to be passed on to the floor without excessive rotation between the foot and the floor. Subtalar joint movements (inversion and eversion) occur about a single axis. Viewed superiorly, this axis is at an angle 23 degrees medial to the long axis of the foot, and viewed laterally, it is at an angle 41 degrees superior to the top of the calcaneus. The midtarsal joints allow the motion of adduction and abduction. In the normal foot, the talonavicular joint is much more mobile than the calcaneocuboid joint. During the stance phase in ambulation, pronation occurs during contact. As body weight is transferred from the heel to the forefoot during propulsion, the hindfoot inverts. The midtarsal joints then lock during weight bearing, and the midfoot becomes a rigid lever to accept the body weight across all five metatarsal heads. In the early stages of rheumatoid joint destruction, joints become hypermobile. The unrestricted movement at the talonavicular joint allows the foot to go into excessive pronation with weight bearing. This 1152 PHYSICAL THERAPY

6 occurs following heel contact as the leg internally rotates on a planted foot, which causes subtalar eversion. The calcaneus then lies lateral to the talus while the cuboid and navicular are almost parallel. In this position, free motion is further allowed at the midtarsal joints, and the midfoot locking mechanism is absent. Therefore, the deformity of the subtalar and midtarsal joints that ensues with progressive rheumatoid arthritis is both a direct result of the disease process at the joints and an indirect result of the acquired abnormalities of the resultant gait pattern. Observational analysis of the gait patterns of a patient with a pronated foot reveals an overall pattern of decreased step length with slow and clumsy forward progression. Initial contact with the floor is made with the medial border of a flat foot. There is diminished balance in single-limb support because of the inability of the subtalar joint to provide stability between the leg and the foot. This results in a prolonged, double-support phase of the gait cycle. Marshall and associates 10 reported that two major gait deviations are seen with rheumatoid changes at the subtalar joint. Plantar flexion of the ipsilateral leg occurs during the swing phase, and heel rise during the stance phase occurs after the contralateral heel strike. These deviations have the effect of reducing horizontal forces through the ankle at initial contact and prolonging the double-support phase of gait, which diminishes the stresses on a single foot. Shields and Ward proposed that the deformity of pronation of the foot leads to genu valgum of the ipsilateral leg in patients with rheumatoid arthritis. 11 The medial displacement of the ground reaction force throughout the stance phase was reported to cause a valgus stress at the knee. Genu valgum was reported to be clinically observable during the period of singlelimb support. Physical examination revealed a lax medial collateral ligament of the knee. Physical examination of the foot and ankle of a patient with a pronated foot deformity reveals several characteristic findings. The patient notes tenderness to palpation in the area of the subtalar and midtarsal joints and complains of feeling foot fatigue after prolonged standing. Passive range of motion may be limited in inversion. Testing of the posterior tibialis muscle will show diminished strength and may elicit pain. The weakness is caused by the chronically elongated position the muscle assumes with a pronation deformity. Tenosynovitis can occur in the posterior tibial tendon near its attachment on the cuboid. When this occurs, the patient will perceive pain during resistive strength testing of the muscle. The patient may also complain of pain during the midstance phase of gait as this muscle contracts. The posterior tibialis muscle is responsible for limiting pronation and providing medial stability when weight bearing occurs. With advanced disease, the tendon erodes, PRACTICE lending further instability to the midtarsal joints. Examination at this stage reveals hypermobility in the pronation range. Hallux Valgus In the development of hallux valgus, the hallux internally rotates and migrates with a valgus angulation. This position causes ah overstretch of the medial ligaments and tendons and a shortening of the lateral structures. With the hallux in this abnormal position during ambulation, the normal kinematics of the MTP joints are disrupted. Normally, in a diarthrodial joint, a smooth gliding motion occurs with flexion and extension. The surface velocities are tangential to the joint surface until the extremes of range of motion, when they become perpendicular to the joint and compression or distraction occurs. Hallux valgus, with or without bunion formation, results in an alteration of the surface velocity direction. This causes extreme compression and distraction at the first MTP joint during the motion necessary for normal gait. Thus, the arthritic changes in the great toe are the result of both the primary disease and the secondary effect of weight bearing in an abnormal posture. The deformity of hallux valgus prevents the first metatarsal head from making floor contact and accepting the normal weight-bearing loads. Observational gait analysis of the patient with hallux valgus will show deviations in the middle and late stages of stance. As the body weight moves forward on a planted foot, the patient with hallux valgus will tend to keep his weight on the lateral border of the foot. If the patient also has a pronation deformity, and thus is unable to supinate, he will tend to keep his body weight posterior. This posterior shift results in a late heel rise. The period of single-limb support will be diminished. Hammer or Claw Toes and Metatarsal Head Subluxation As in the other deformities, hammer or claw toes and metatarsal head subluxation are results of both the primary disease changes and the forces and kinematics of normal ambulation. Synovitis of the MTP joints causes capsular distension and eventual loss of cartilage. The proximal phalanx subluxation occurs in a dorsal direction. Muscle activity of the toe extensor muscles during the swing phase of gait and the passive dorsiflexed position of the toes in terminal stance tend to contribute to the dorsal subluxation. Once the displacement occurs, the intrinsic muscles cannot function as flexors of the MTP joints. The tendons migrate to the intermetatarsal space and become extensors of the proximal phalanx. In ambulation, the intrinsic muscles function in the terminal Volume 62 / Number 8, August

7 TABLE 3 Surgical Management of the Rheumatoid Foot Type Prophylactic synovectomy Tendon repair or transfer Soft tissue excision Osteotomy Partial or total arthroplasty Resection of bone Joint fusion Indication Persistent inflammation Ruptures Toe deformities RA nodules Angular deformity Joint destruction Pain Instability Joint destruction Pain Deformity Instability Pain Area MTP joints Achilles tendon Flexors/extensors of toes Great toe, abductor/adductor Plantar surface Achilles tendon Forefoot MTP joints Ankle Metatarsal heads Talonavicular joint Tibiotalar and subtalar joints Subtalar and midtarsal joints Interphalangeal joints stages of stance. If the tendons of the intrinsic muscles have become displaced dorsally, each time the muscles contract the toe deformities and dorsal subluxation will be accentuated. Observational gait analysis of the patient with hammer or claw toe deformities and metatarsal head subluxation will reveal diminished roll off at terminal stance, decreased single-limb stance time, and decreased cadence. He loses the propulsive forces during the end of stance phase, resulting in an awkward progression in gait. His single-limb balance is diminished as the length of the functional lever of his foot is shortened. Painful Heel The final problem to be discussed is a painful heel secondary to subplantar spur formation and tendocalcaneal bursitis. When a subplantar spur exists, pain is caused by direct soft tissue compression from the spur with weight bearing. The pain perceived with an inflamed bursa under the Achilles tendon occurs whenever this bursa is compressed. Compression occurs with a stretch of the Achilles tendon or with active contraction of the gastrocnemius or soleus muscles. The position of comfort for a patient with this problem is one of passive plantar flexion. Observational gait analysis of the patient with these problems reveals certain characteristic findings. With both diagnoses, the patient will complain of pain at initial heel contact and therefore will try to avoid this stage by various maneuvers. The least painful alteration usually is to make initial contact with the toe rather than the heel and then to keep the heel slightly off the ground throughout the gait cycle. If the pattern of heel strike is maintained, the patient will usually take shorter steps and decrease his velocity. Both of these maneuvers result in a diminished ground reaction force. If the pain problem is caused by a bursitis, the ankle may be held in plantar flexion during swing phase rather than in the normal position of neutral. If this occurs, there will be an increase in hip flexion during swing phase to clear the advancing limb. To decrease both the time of contraction and the length of elongation of both the gastrocnemius and soleus muscles in midstance and late stance, the patient may take a shorter stride with the uninvolved limb. During physical examination, tendocalcaneal bursitis will cause painful active plantar flexion and painful passive and active dorsiflexion. Swelling will be observable at the site of the insertion of the Achilles tendon. The patient will perceive tenderness to palpation over the spur. Longstanding bursitis about the heel will result in decreased ankle range of motion in dorsiflexion. TREATMENT Both nonsurgical and surgical treatment approaches can be considered when dealing with the rheumatoid foot. Specific recommendations for nonsurgical and surgical management are delineated in Tables 2 and 3. Nonsurgical Management Few data have been reported on the actual effects of nonsurgical management. Joint protection methods are known to be generally helpful to the patient with rheumatoid arthritis. Methods of joint protection in the foot consist of selecting appropriate footwear, decreasing weight-bearing stresses during exacerba PHYSICAL THERAPY

8 tion, using an assistive gait device or orthosis, and paying attention to pain or swelling. Appropriate footwear can accommodate the deformity, stabilize the hypermobile joints, and reduce deforming forces. The forefoot deformities are best accommodated in a shoe with an extra-depth or extrawidth toe box or both. When the upper portion of the shoe is made of a soft leather, the pressure on the toes from hammer or claw deformities is decreased. Plantar spurs or ulcerations under the metatarsal heads require a soft, closed-cell foam insert with cutout areas for the spur or protruding metatarsal heads. An extra-depth shoe should always be used to accommodate for height of an insert. Heel height should be approximately 2.54 cm (1 in), and the insert should be made of a soft material such as crepe. A soft sole diminishes the joint compression force occurring with weight bearing and is therefore beneficial. A firm medial counter and longitudinal arch support are suggested to support the hindfood in a neutral position rather than allowing valgus to occur with weight bearing. If excessive pronation still occurs with weight bearing, orthotic intervention should follow. Three commercially available types of shoes are applicable to the needs of the rheumatoid foot. These are the oxford, the protective shoe with a rigid sole (postoperative shoe), and the shoe made with an extra-depth or extra-width toe box. When these shoes are needed but cannot be worn in comfort, a custom-molded shoe should be considered. During periods of exacerbation, avoidance of weight-bearing stresses on the affected joints is necessary and appropriate. Complete bed rest may be indicated, but the use of assistive gait devices may be sufficient to "unload" the affected joints. These restrictions are usually acceptable to the patient with rheumatoid arthritis during periods of exacerbation. Limited weight bearing should be continued until strength of the lower extremity musculature and reduction of joint swelling is sufficient to avoid further joint damage. Assistive devices, such as crutches, add the function of weight bearing to the joints of the upper extremity. Therefore, judiciously choosing an appropriate aid and monitoring the status of the upper extremity joints are important. Data from studies of joint protection on the rheumatoid hand suggest that although an orthosis is often used as a means of protection, a deformity cannot be corrected without surgical intervention. 12 However, just as the various wrist orthoses give an advantageous mechanical alignment to more distal hand structures, a hindfoot orthosis can afford better function to the distal forefoot. Devices can be classified as functional or balance orthoses. The purpose of a functional device is to stabilize an anatomical segment during the function of either that segment or a distal part. A functional PRACTICE orthosis is indicated for a hypermobile joint and thus must be constructed of a rigid material to restrict motion adequately. The main indication that a functional orthosis should be used for the rheumatoid foot is the instability seen at the subtalar and midtarsal joints. An example of a functional orthosis is a custom-molded thermoplastic device inserted in the shoe to limit motion and is designed to be worn during all weight-bearing activities. If malalignment or hypermobility in a mediolateral plane exists in joints proximal to the subtalar joint, orthotic stabilization may be needed at the ankle and knee. The desired resultant alignment is that of normal single-limb weight bearing. Therefore, the knee should have no varus or valgus angulation, and the foot should be supported in neutral. A balance orthosis functions to distribute pressure. An example of this is a metatarsal bar that is placed exteriorly on the sole or inside the shoe to redistribute the weight-bearing pressure. To do this most effectively, the bar should be placed proximally to the metatarsal heads. During walking, as body weight is transferred to the forefoot, the weight is not borne on the subluxed metatarsal heads but is absorbed proximally in the foot. As the body advances over a planted foot, the patient rolls over the metatarsal bar and not over the painful metatarsal heads. The definitive orthotic management may involve a combination of both the functional and the balance types. Recognition of swelling and pain experienced by the patient in particular areas of the foot is the responsibility of all health professionals working with the patient. Swelling is the first visible abnormality, and intervention should be initiated at this stage. Swelling and pain occur at the metatarsal heads, at the Achilles tendon insertion, and over the dorsum of the tarsal bones. As mentioned above, the patient may report a feeling of "walking on marbles" from depressed metatarsal heads and may gradually develop a flat foot from the pronation occurring at the subtalar and talonavicular joints. When these situations develop, the patient should be referred to an appropriate member of the management team. The compositon of the management team will vary among institutions as will the responsibilities of each team member. Generally, the team includes a rheumatologist, a registered nurse, a physical therapist, and an occupational therapist. At some centers, a podiatrist and orthotist may also be available. Any of these professionals should be competent in recognizing the outlined deformities. Generally, the physician or the physical therapist will observe the gait deviations and note the physical exam findings consistent with foot deformities associated with rheumatoid arthritis. It is then their role to initiate treatment and to seek the help of the occupational therapist, orthotist, or podiatrist as needed. The registered nurse taking Volume 62 / Number 8, August

9 care of the patient must be informed of the problems and the proposed treatment. The nurse plays an important role in helping avoid deforming forces in the patient while he is under nursing care. may involve recommending postoperative footwear, issuing assistive devices, and reviewing joint protection methods in regard to a new level of mobility. Surgical Management The goal of surgical management of the rheumatoid foot is to provide a stable weight-bearing support rather than to return normal motion (Tab. 3). 13 Of the commonly employed procedures, resection of the metatarsal heads is a particularly effective technique that often affords major relief from a painful weightbearing foot. The postoperative concern of the physical therapist is to assist the patient in becoming ambulatory. This CONCLUSION Foot deformities and problems commonly occur in the patient with rheumatoid arthritis. With an understanding of the pathomechanics and a recognition of the clinical picture of these patients, the physical therapist may assist in and encourage early intervention. With the appropriate treatment, these patients may continue to ambulate with greater efficiency and decreased pain. REFERENCES 1. Calabro JJ: A critical evaluation of the diagnostic feature of the feet in rheumatoid arthritis. Arthritis Rheum 5(1): 10-29, Giannestras N: Foot Disorders. Philadelphia, PA, Lea & Febiger, 1976, p Elbaor J, Thomas W, Weinfeld M, et al: Talonavicular arthrodesis for rheumatoid arthritis of the hindfoot. Orthop Clin North Am 7: , Thomas WH: Rheumatoid arthritis of the ankle and foot. In Cooper, Funk, Brindley, et al (eds): American Academy of Orthopaedic Surgeons: Instructional Course Lectures. St. Louis, MO, The CV Mosby Co, 1979, pp Inman VT, Ralston HJ, Todd F: Human Walking. Baltimore, MD, The Williams & Wilkins Co, 1981, pp Mann RA, Coughlin MJ: The rheumatoid foot: Review of literature and method of treatment. Orthopaedic Research 8 (8): , Root M, Orien W, Weed J: Normal and Abnormal Function of the Foot: Clinical Biomechanics. Los Angeles, CA, Clinical Biomechanics Corp, 1977, vol 2, pp , Kettlecamp DB, Leaverton PE, Misol S: Gait characteristics of the rheumatoid knee. Arch Surg 104:30-34, Stauffer RN, Chao EY, Gyory AN: Biomechanical gait analysis of the diseased knee joint. Clinical Orthopedics and Related Research 126: , Marshall RN, Meyers DB, Palmer DG: Disturbance of gait due to rheumatoid disease. J Rheumatol 7 (5): , Shields MN, Ward JR: Treatment of related knee-ankle-foot deformities in rheumatoid arthritis. Phys Ther 46: , Flatt A: Care of the Rheumatoid Hand. St. Louis, Mo, The C V Mosby Co, 1963, pp Kuhn J: The foot in chronic arthritis. Clin Orthop 16: , PHYSICAL THERAPY