Arthritis

Rheumatoid arthritis

Rheumatoid arthritis is a disease which affects many systems and many joints. It can devastate the wrist and hand. The synovitis destroys ligaments, tendons and joints, producing pain, deformity and loss of function. Zig-zag collapse is typi­cal of rheumatoid arthritis — as one joint deforms in one direction, the next deforms in the opposite (e.g. boutonniere, swan neck, ulnar drift of metacarpophalangeal joints with radial drift of wrist). As the joints deform, the tendons overlying them gain a greater mechanical advantage, leading to greater deformity. Simple activities of daily living, such as thumb pinch and opening jars, stress the weakened ligaments and produce worsening deformity (particularly ulnar drift at the metacarpophalangeal joints).

Assessment

For the hand to function well, it must be placed accurately and firmly in place — the elbow, shoulder and wrist must be carefully assessed as well.

History. What are the patient’s social circumstance, mobility, occupation and general health? These all influence the treatment that is offered. Which particular joints concern the patient? What is the patient’s problem with these joints —pain, instability, weakness, stiffness, appearance? Are there symptoms elsewhere, particularly the shoulder and elbow? What specific functional problems are there?

Examination. Does the patient have a typical pattern of deformity? Are the joints stable or unstable? Is there synovitis in the joints or tendons? What is the active and passive range of movement of each joint? Are these movements painful? Are the tendons intact? Are the muscles weak? Is there a median nerve palsy (from synovitis in the carpal tunnel) or a radial or ulnar nerve palsy (much rarer, from synovitis around the elbow)? Pinch grip and power grip?

Deformities in rheumatoid arthritis

Wrist:

Radial deviation

Carpal supination

      Prominent, unstable ulnar head

Extensor tenosynovitis

Metacarpophalangeal joints:

Flexion

Ulnar deviation

  Subluxation, dislocation

  Fingers:

Swan neck

Boutonniere

Extensor tendon rupture

Flexor tendon rupture

Flexor synovitis

•Congenital deformities

  Type                                               Example
 
Failure of formation                        Longitudinal absence-radial
                                                      (radial club hand), longitudinal
                                                       absence-ulnar (ulnar club
                                                        hand), longitudinal absence-
                                                        central (lobster claw hand)
  Failure of differentiation                  Syndactyly (fingers joined by
                                                        skin and sometimes bone)
  Duplication                                  Thumb duplication
  Overgrowth                                  Macrodactyly
  Undergrowth                              Thumb hypoplasia
  Constriction ring syndrome              Simple rings
            Generalised skeletal abnormalities      Marfan’s, Turner’s, Down’s, etc.

Nonoperative treatment

Rheumatoid arthritis is best managed with a team comprising the patient, physician, physiotherapist, occupational thera­pist, social worker and surgeon. Drugs can reduce symptoms and slow progression. Resting splints are helpful during flare-ups. Appliances can help with tasks such as turning on taps or opening jars, which would otherwise strain and damage the lax ligaments. Static splints stabilise and protect lax joints and improve function.

Surgery

The hand can never be made normal but many patients benefit from carefully planned surgery. Surgery must be tailored for each patient. In general, the shoulders, elbow and wrist should be treated before the hand, and reliable operations (e.g. thumb or wrist fusion) should be undertaken before more uncertain operations (e.g. soft-tissue reconstruction).

  There are four indications for surgery:

pain;

  prevention of progression;

  improving function;

improving appearance.

Synovectomy of the wrist joint, metacarpophalangeal joints and interphalangeal joints should be considered if medical treatment has failed to control pain, with minimal joint damage on radiographs. Synovectomy of the flexor tendons may be needed if the patient has flexor tendon rupture, poor active finger flexion, trigger finger or carpal tunnel syndrome. Synovectomy of the extensor tendons (often with excision of the distal ulna) removes unsightly swelling and reduces the risk of rupture.

Excision of the distal end of the ulna, often with reconstruc­tion of the associated extensor tendon ruptures, reliably improves pain and function, and prevents extensor tendon rupture.

Replacement of the wrist with silicone or metal—polyethylene implants carries a high risk of failure. Replacement of the metacarpophalangeal joints helps pain and appearance, and the implants can last for a considerable time; the extensor tendons, collateral ligaments and intrinsic tendons all need careful reconstruction to overcome ulnar deviation. Replacement of the proximal interphalangeal joint can maintain some movement but there is an appreciable failure rate.

Fusion of the radiocarpal joint gives a pain-free, stable platform for the hand. An intramedullary pin with bone graft usu­ally suffices. Fusion of the thumb metacarpophalangeal joint and the finger distal interphalangeal joints can considerably improve function by providing stability and removing pain.

Tendon reconstruction is sometimes necessary. A ruptured extensor pollicis longus is treated effectively with an extensor indicis transfer. A ruptured flexor pollicis longus is most reliably treated, if the patient’s symptoms need it by thumb interphalangeal joint fusion. Multiple tendon ruptures on the dorsum of the wrist are managed with side-to-side suture to intact tendons, tendon transfer or a tendon graft.

Swan neck deformity (Fig. 30.15) is caused by imbalance of the flexor and extensor tendons over the finger, subluxation of the metacarpophalangeal joint, tightness of the intrinsic muscles and failure of the palmar plate of the proximal interphalangeal joint. It may need splintage, manipulation, tenodesis, intrinsic muscle release, lateral band release or even fusion depending on the cause and severity.

Osteoarthritis

Wrist

The radiocarpal joint may develop osteoarthritis after an intra-articular fracture or infection; it can develop without an obvious cause. If splintage, analgesics and modification of activity fail, then fusion of the wrist at about 20degree extension with a dorsal plate and bone graft will give a stable, pain-free wrist. Arthritis may develop around the scaphoid after a scaphoid fracture or a scapholunate ligament rupture. If simple measures fail, then bone excision, a limited fusion or total wrist fusion may be needed. The pisotriquetral joint can develop osteoarthritis. There is focal tenderness over the joint and 30degree supination radiographs show the pathology (Fig. 30.16). If rest, splintage and a steroid injection fail, pisiform excision is helpful.

Hand

Osteoarthritis of the hand is most commonly part of a pre­disposition to generalised osteoarthritis, particularly in late middle-aged females. Infrequently it follows joint injury or infection. The proximal interphalangeal joints may be involved (Bouchard’s nodes), the distal interphalangeal joints (Heberden’s nodes) or the carpometacarpal joint of the thumb. The metacarpophalangeal joints and finger carpometacarpal joints are rarely involved. The symptoms do not correlate well with the radiographs. Occasionally surgery is needed. Fusion of the distal interphalangeal joint removes pain and gives good function. The proximal interphalangeal joint can be fused, but the loss of flexion is a significant hindrance; the alternative of replacement with silastic is unreliable. The basal joint of the thumb usually responds to analgesics, steroid injections and splintage. Excision of the trapezium helps the pain but the thumb is weakened. Filling the space with a rolled-up length of palmaris longus, or suspending the base of the first metacarpal with a sling made from part of the flexor carpi radialis tendon, may improve stability of the thumb.

Other forms of arthritis

Gout can easily be mistaken for a septic arthritis in the wrist or finger joints. The diagnosis is confirmed by measuring the serum urate and examining the joint aspirate under a micro­scope. In more chronic forms, tophi are seen beneath the skin and bone can be eroded. Gout can also cause tenosynovitis leading to trigger finger or carpal tunnel syndrome. Psoriasis often involves the joints of the hand and wrist. The nails are pitted and bone may resorb.