Rheumatoid Thumb

Nalebuff Classification

 

Type I - Boutonniere 

- commonest

- MP flexion /  IP hyperextension

- usually EPB rupture with EPL subluxation

 

Rheumatoid Boutonniere Thumb

 

Type II

- Boutonniere & Swan Neck

- doesn't exist according to Nalebuff

 

Type III - Swan Neck

- second most common

- primary deformity is OA and dorsal subluxation of CMC

- hyperextension MPJ / IPJ flex

 

Rheumatoid Thumb Swan Neck

 

Type IV - Gamekeepers

- due to MCPJ synovitis

- stretches UCL

- either synovectomy / UCL reconstruction

- or fusion

 

Rheumatoid Gamekeepers Thumb

 

Type V - Stretched Volar Plate MCPJ

- differentiated from Swan Neck by no CMC disease

- fusion of MCPJ

 

Type VI - Arthritis Mutilans

- destruction and instability MCPJ / IPJ

- arthrodesis only option

 

RA Thumb Destruction IPJ

 

Boutonniere Deformity

 

RA Thumb Boutonniere's

 

Aetiology

 

Synovitis of MCPJ

- extensor Hood stretched

- EPB ruptures

- EPL tendon displaced Ulnarward & Volarly

- becomes flexor 

 

Management

 

1.  Flexible MCPJ

 

A.  Synovectomy of MCPJ

 

B.  EI to EPB / EPL Centralisation

 

C.  EPL transfer + fusion IPJ

- divide EPL over P2 and reattach to base P1

- good correction early 

- but 66% recurrence

 

2.  Fixed MCPJ / Flexible IPJ

 

Arthrodesis / Arthroplasty MCPJ

- arthrodesis better suited for young, high demand

- arthroplasty better suited to low demand

 

Rheumatoid MCPJ Fusion

 

3.   Fixed IPJ and MPCPJ

 

A.  Fuse both 

- best option 

 

B.  IPJ fusion / MCPJ arthroplasty

- with arthroplasty have to balance soft tissues

- reroute EPL as above

 

Swan Neck

 

Aetiology

 

RA Thumb Swan NeckRA Swan Neck Deformity

 

Disease at CMCJ

- leads to dorsal subluxation of CMCJ 

- beak ligament is not functional

- result is adduction contracture

 

MCPJ hyperextension

- ? volar plate stretches

 

IJP flexion

- ? Mallet rupture 

 

Management

 

A.  Trapeziectomy and LRTI

 

Rheumatoid Swan Thumb Trapeziectomy

 

B.  +/- MCPJ fusion

 

Thumb MCPJ Fusion