Mechanical wearing down of flexor tendons in rheumatoid arthritis as a result of extreme volar-flexed intercalated segment instability

Spontaneous flexor tendon rupture due to atraumatic chronic carpal instability

Background Spontaneous flexor tendon rupture is considered to be invariably associated with previous hand/wrist injury or systemic disease such as rheumatoid arthritis. Case Description A 54-year-old man presented with a 4-month history of mild ulnar wrist pain and spontaneous left little finger flexion loss in the absence of distant/recent trauma and systemic arthropathy. Surgical exploration confirmed a zone IV left little finger flexor digitorum profundus (FDP5) attritional rupture (100%), ring finger flexor digitorum profundus (FDP4) attenuation (40%) and a disrupted lunotriquetral ligament and volar-ulnar wrist capsule. Volar subluxation of the narrowed carpal tunnel resulted in flexor tendon attrition against the hamate hook. A side-to-side tendon transfer was performed along with a lunotriquetral ligament repair and temporary Kirschner wire fixation. At 6 months the patient had full active, synchronous flexion of the ring and little fingers and reduced wrist pain. Literature Review Traumatic flexor tendon ruptures have been reported following distal radius/hamate hook fractures, from carpal bone osteophytes, accessory carpal bones and intraosseous ganglia. Attritional ruptures caused by chronic, degenerative carpal pathology are less common. Clinical Relevance This case highlights an unusual cause of flexor tendon rupture due to chronic carpal instability.

Tendon reconstruction for the rheumatoid hand

Tendon involvement in rheumatoid arthritis is frequent and might even be the first sign of the disease. In long-standing untreated conditions, especially in combination with bony erosions, tenosynovitis may lead to tendon fraying and finally tendon rupture. Tendon reconstruction includes tendon grafting and tendon transfer. Direct repair is almost never possible in patients with rheumatoid arthritis, because the inflammatory process produces extensive tendon damage over a long distance. In patients with significant impaired joint function, additional joint treatment should be planned at the same time as tendon reconstruction.

[Management of affected flexor tendons in rheumatoid arthritis of the hand]

The affection to the flexor tendons of the patient with rheumatoid arthritis represents a substantial rheumatic change in the hand, which is characterized by restriction of movement, ulnar deviation in the level of the metacarpophalangeal joint and palmar incomplete dislocation. Early treatment by removing any possible constriction areas in synovial proliferations in the area of the flexor pullies or a complete tendosynovectomy makes an extensive restitution possible. In the case of only one ruptured flexor tendon, it can be treated by the transfer of the neighboring superficialis tendon or a tendon transplant. If there are multiple ruptures, the results will be clearly worse in regard to movement and strength, whereby as a rule the result is seriously influenced by articular destruction. Therefore, an early tendosynovectomy and a preventive operation to the wrist have to be recommended.