1. 1. Rheumatoid arthritis - bone erosion
Figure Rheumatoid arthritis. Progressive joint destruction documented by hand radiographs. A, Diffuse periarticular osteopenia, with early joint-space narrowing in the wrist and some erosions at the margins of the joints (eg, left third proximal interphalangeal joint, arrow), subluxation of right thumb metacarpophalangeal joint is seen. B, Three years later, progressive joint-space narrowing in wrist, metacarpophalangeal joints, and proximal interphalangeal joints is seen. Erosion and partial collapse of the wrist joints and erosion of the right ulnar styloid process are also seen (arrow). C, One year later, progressive destruction of wrist joint (more severe in right wrist) is seen, with loss of joint space, progressive collapse of carpal bones, and complete loss of the right ulnar styloid process. Severe erosions and cystic changes are present in distal ulna and radius bilaterally (arrows). Patients who are seropositive with long-standing severe erosive arthritis and particularly those on glucocorticoids are at risk of developing septic arthritis of one or several joints. Most infections are due to Staphylococcus aureus. The development of septic arthritis in a rheumatoid arthritis patient can be misdiagnosed initially as an exacerbation of rheumatoid arthritis.

2. A and B, Radiographic features of aggressive, early rheumatoid arthritis.
Figure 5-7. A and B, Radiographic features of aggressive, early rheumatoid arthritis. Evidence of soft tissue swelling of the metacarpophalangeal and proximal interphalangeal joints can be seen on the hand radiograph of this 61-year-old woman with rheumatoid arthritis for 1 year. In the early, pre-erosive stage, juxta-articular osteoporosis appears, caused by the inflammation of the surrounding synovium. There is symmetric joint space narrowing of several metacarpophalangeal and proximal interphalangeal joints of both hands and subtle erosions of the right third and both fourth metacarpophalangeal joints. The carpus is involved as well, and the carpal margins are becoming indistinct, reflecting continued active synovitis. Soft tissue swelling from synovitis is present at the wrists and many of the digits. (Courtesy of Eric L. Matteson and Thomas G. Mason.)

3. 2. Ulnar deviation.
Figure 5-8. Ulnar deviation. Ulnar deviation of the digits at the metacarpophalangeal joints is often seen in conjunction with radial deviation at the wrists, and is often accompanied by swan neck deformity, double angle thumb, and interosseous muscle wasting. Marked functional impairment frequently results. The deformity is bilateral, but often more marked on the dominant hand. A nodule is preserved over the left fifth proximal interphalangeal (PIP) joint. Joint swelling of several PIP joints is evident, as are characteristic thumb deformities.

4. 3. Advanced rheumatoid arthritis of the hands: metacarpophalangeal replacement.
Figure 5-9. Advanced rheumatoid arthritis of the hands: metacarpophalangeal replacement. Chronic synovitis of the wrists and finger joints in long-standing rheumatoid arthritis is seen. Volar subluxation and ulnar deviation at the metacarpophalangeals led to considerable hand dysfunction especially in the more affected dominant right hand, in which metacarpophalangeal joint replacement has been undertaken. Swan neck deformities are present in multiple digits, especially the third to fifth digits of the left hand. A, The palmar view dramatically demonstrates global muscle wasting from long-standing disease. B, Dorsal view.

5. Advanced rheumatoid arthritis of the hands: metacarpophalangeal replacement.
Figure 5-9. Advanced rheumatoid arthritis of the hands: metacarpophalangeal replacement. Chronic synovitis of the wrists and finger joints in long-standing rheumatoid arthritis is seen. Volar subluxation and ulnar deviation at the metacarpophalangeals led to considerable hand dysfunction especially in the more affected dominant right hand, in which metacarpophalangeal joint replacement has been undertaken. Swan neck deformities are present in multiple digits, especially the third to fifth digits of the left hand. A, The palmar view dramatically demonstrates global muscle wasting from long-standing disease. B, Dorsal view.

6. Dactylitis in the hand and foot
Figure 3-7. A and B, Dactylitis is one of the hallmark clinical features of psoriatic arthritis (PsA) occurring in 16-48% of reported cases [], []. Dactylitis is characterized by uniform swelling of the digit. According to some authors, dactylitis is predominantly due to swelling and inflammation in the flexor tendon sheaths [], although other groups have recorded joint synovitis as well as tenosynovitis []. Chronic, non-tender, diffuse dactylitic swelling occurs in PsA and may be less of an indicator of active disease than tenderness within the swollen digit. Rarely, unilateral limb edema is seen in PsA and, although there are clinical similarities with the limb edema seen in rheumatoid arthritis (where an abnormality of lymphatic vessels has been described), this may be an extreme example of 'limb dactylitis' (see <A HREF="javascript:void(0)" onClick="window.open('figure_show.asp?fid=APA ','figures','width=500,height=400,resizable=yes,scrollbars=yes')">this image</a>).

7. 4. Left and right hand of a 67-year-old male at first presentation
Figure At this time he had been visiting his primary care physician for nine years with 'rheumatoid arthritis'. He had pain and stiffness in his left shoulder, left hand, and knees. He said that he had had psoriasis for 26 years. Examination revealed osteoarthritis of his knees. He had synovitis of the second and third left metacarpophalangeal joints, left wrist, and dactylitis of his left index finger (A) with deformity of his right index (B) and left middle distal interphalangeal joints. Radiographs showed osteolysis of the left second toe terminal phalanx and normal sacroiliac joints.

8. 5. Boutonniére deformity in rheumatoid arthritis
Figure Boutonnière deformity. A, There are boutonnière deformities of joints, including the thumb of the right hand and the second to fifth digits of the left hand. Swan neck deformity of the index finger of the right hand and multiple rheumatoid nodules are also present. These deformities develop as the disease becomes established. Wrist swelling, tenosynovitis of the extensor tendon of the third digit of the right hand, and profound interosseous muscle wasting are additional features of the hand in rheumatoid arthritis. The skin of the digits may appear atrophied. There is chronic synovial thickening of multiple joints, especially the wrists. B, The boutonnière (buttonhole) deformity is characterized by hyperextension at the metacarpophalangeal, flexion at the proximal interphalangeal, and hyperextension at the distal interphalangeal joints. Synovitis causes relaxation of the dorsal slip, with the proximal interphalangeal protruding through the radial and ulnar ligaments of the dorsal aponeurosis, which are below the usual axis of motion of these bands. The proximal interphalangeal joint passes through the defect much as a button is passed through a buttonhole.

9. 7. Asymmetric hand swelling in rheumatoid arthritis
Figure Asymmetric hand swelling. Asymmetric hand swelling in rheumatoid arthritis may sometimes be seen, perhaps because of the sometimes capricious nature of the disease, relative overuse of the more affected joint, or because of secondary disease, such as septic arthritis of an already inflamed joint. For reasons that remain unclear, but probably are related to neuroimmunologic phenomena, patients with rheumatoid arthritis who suffer from a stroke or, as in this case, from polio, often are seen to have little if any active synovitis in the extremity affected by the neurologic disorder. Erosive disease, however, may still be present.

10. 6. Swan neck deformity in rheumatoid arthritis
Figure Swan neck deformity. The swan neck deformity is caused by joint swelling and associated tenosynovitis with subsequent contracture of the intrinsic (lumbrical and interosseous) hand muscles. There is flexion at the metacarpophalangeal, hyperextension at the proximal interphalangeal, and flexion at the distal interphalangeal joint evident in fingers, especially the third, fourth, and fifth, but to a lesser extent also in the index finger. In early disease the deformity can be passively corrected; later, functional impairment may result from inability to flex at the proximal interphalangeal joint so that the patient is unable to make a fist.

11. Ulnar styloid prominence in rheumatoid arthritis
Figure Ulnar styloid prominence in rheumatoid arthritis. Chronic synovitis in the wrists has resulted in carpal ligament laxity, leading to prominence of the ulnar styloid processes. There is profound interosseous muscle wasting, and tenosynovitis of the extensor carpiulnaris of the left hand.

12. Stenosing tenosynovitis (trigger finger)
Figure Stenosing tenosynovitis (trigger finger). A, Synovitis of the tendon sheaths can lead to swelling, limitation of motion, and tendon rupture. Stenosing tenosynovitis can lead to "trigger finger," evident in the fourth finger of the left hand. Triggering occurs when the inflamed tenosynovial tissue cannot move through the tendon sheath. Stenosis of the A-1 pulley can be palpated in the palm just proximal to the affected metacarpophalangeal joint. B, Stenosing tenosynovitis. Tenosynovitis of the flexor tendon can lead to the trigger finger syndrome. With tenosynovitis, the digit is blocked in the flexed position (arrow with vertical bar), making extension difficult or even impossible. If the affected tendon is able to pass through the fibrous tendon sheath, a palpable "pop" may be detected. The action may be painful. The tendon may also be blocked in the extended position (arrow). Swelling of the tenosynovium proximal to the stenosed annular ligaments may be palpable in the palm as swelling. (Courtesy of Alan T. Bishop, MD.)

13. Stenosing tenosynovitis (trigger finger)
Figure Stenosing tenosynovitis (trigger finger). A, Synovitis of the tendon sheaths can lead to swelling, limitation of motion, and tendon rupture. Stenosing tenosynovitis can lead to "trigger finger," evident in the fourth finger of the left hand. Triggering occurs when the inflamed tenosynovial tissue cannot move through the tendon sheath. Stenosis of the A-1 pulley can be palpated in the palm just proximal to the affected metacarpophalangeal joint. B, Stenosing tenosynovitis. Tenosynovitis of the flexor tendon can lead to the trigger finger syndrome. With tenosynovitis, the digit is blocked in the flexed position (arrow with vertical bar), making extension difficult or even impossible. If the affected tendon is able to pass through the fibrous tendon sheath, a palpable "pop" may be detected. The action may be painful. The tendon may also be blocked in the extended position (arrow). Swelling of the tenosynovium proximal to the stenosed annular ligaments may be palpable in the palm as swelling. (Courtesy of Alan T. Bishop, MD.)

14. 7. Acute tenosynovitis in rheumatoid arthritis
Figure Acute tenosynovitis in rheumatoid arthritis. Massive wrist synovitis and tenosynovitis of the flexor tendons are evident in active disease. Flexion contractures have developed in the left hand, which improved with therapy. Swelling of flexor synovial sheaths is apparent in the right hand proximal to the swollen carpus, especially the flexor carpi radialis.

15. 8. Tenosynovitis of the foot.
Figure Tenosynovitis of the foot. A large tenosynovial cyst is present on the right anterior tibial tendon in this 60-year-old man with a 5-year history of rheumatoid arthritis. Rupture of this tendon results in loss of the longitudinal foot arch and pes planus. Peroneus tenosynovitis affects the left foot.

16. PsA with rheumatoid-like features - fibular deviation of the toes
Figure 4-7. Feet of the same patient shown in <A HREF="javascript:void(0)" onClick="window.open('figure_show.asp?fid=APA ','figures','width=500,height=400,resizable=yes,scrollbars=yes')">this image</a> demonstrating fibular deviation of the toes. Although the pattern of polyarticular disease is reminiscent of rheumatoid arthritis, the radiograph is characteristic of PsA with joint fusion or ankylosis at several sites, lack of osteopenia and a characteristic pencil-in-cup-type deformity at the fifth metatarsophalangeal (MTP) joint on the left (arrow), with proximal joint osteolysis and distal joint new bone formation at the capsule. The entheseal bone formation at the distal capsule forms the cup in the pencil-in-cup deformity of the fifth MTP joint on the left foot. This case illustrates how a disease pattern that appears to be primarily synovial-based on clinical findings can in fact be associated with enthesitis and bone-based pathology on radiographic findings. Some patients classified as PsA polyarthritis have juxta-articular osteoporosis and erosions only and no evidence of an enthesitis/osteitis-related pathology. Concerns about diagnosing such patients with PsA have been raised.

17. 9. Toe deformities in rheumatoid arthritis
Figure Toe deformities of rheumatoid arthritis. Overlapping of the second and third toes over the first toe of the right foot with marked hallux valgus is seen. Hammer toe deformities (hyperextension of the distal metatarsophalangeal, flexion of the proximal interphalangeal, and extension of the distal interphalangeal joints) are present. Claw toe (extension of the distal metatarsophalangeal and flexion of the proximal interphalangeal with flexion or neutral position of the distal interphalangeal) deformities are also frequently present. Calluses are often present over the protruding proximal interphalangeals, caused by shoes that are too tight to accommodate the deformed foot. Inflammation of the bursa overlying the first distal metatarsophalangeal seen here on the right foot is frequent in hallux valgus. There is almost complete dorsal subluxation at the interphalangeal joint of the left great toe as well.

18. 10. Rheumatoid foot deformities
Figure Rheumatoid foot deformities. Chronic synovitis has led to hallux valgus of the right great toe and fibular deviation, especially of the first three toes. An inflamed bursa has formed on the medial aspect of the right first metatarsophalangeal joint. Profound flatfoot has developed caused by chronic distention and instability of the joint capsules and supporting ligaments of the midfoot and hindfoot. The medial malleoli, tali, and navicular bones of both feet are medially and plantarly rotated, projecting over the medial margin of the foot.

19. 11. Erosive arthritis of the feet
Figure Radiograph of erosive arthritis of the feet. Extensive symmetric erosive changes are evident especially in the metatarso phalangeals and proximal interphalangeals of multiple joints, with advanced destruction of many of the distal metatarsophalangeal heads. Subchondral sclerosis and subchondral cysts are present. Rheumatoid nodules have developed on the left and right fifth distal metatarsophalangeal heads and the distal right first metatarsophalangeal head. Extensive soft tissue swelling is evident around many of the toes.

20. 12. Pes planus in rheumatoid arthritis
Figure Pes planus. Profound pes planus in a 70-year-old woman with rheumatoid arthritis of more than 25 years' duration. Malrotation of the toes, especially of the right foot, is evident. The patient was able to walk with supportive footwear, and declined orthopedic intervention. Also evident is livido reticularis, seen in many patients with vasculopathies. This patient had suffered repeated lower extremity ulcerations; the medial aspect of the left lower extremities demonstrates hyperpigmentation and skin atrophy at the site of one such ulceration.