RA- EXTENSOR TENDONS

Question 1

2 main extensor tendon conditions in RA

Answer 1

1. Tenosynovitis and extensor tendon rupture

2. Extensor tendon subluxation

Question 2

2 main factors causing extensor tendon rupture in RA

Answer 2

1. Tenosynovitis
2. Tendon attrition over bony prominences
   - FPL = scaphoid spur at STT joint
   - EDM and EDC to LF and RF = prominent ulna head
   - EPL = Lister’s tubercle

Question 3

Vaughan-Jackson syndrome

Answer 3

Rupture of extensor tendons from ulnar to radial

Most commonly EDM and EDC to RF and LF

Question 4

5 main causes of drop finger in RA

Answer 4

Drop finger = inability to actively extend finger
5 causes
Flexor side
1. Locked trigger digit (flexor tenosynovitis)
- Dupuytren’s is another cause but not in RA (negative correlation)
Extensor side
2. PIN palsy
3. Extensor tendon subluxation
4. Extensor tendon rupture
Joint
5. MCP volar dislocation
Tenodesis effect = allows differentiation between tendon rupture and other causes

Question 5

3 main surgical options for extensor tendon rupture in RA

Answer 5

Tendon intact = tenosynovectomy to prevent rupture
Tendon not intact = tenodesis and/ or tendon transfer
- resect bony prominences/ spurs causing attrition
- transpose superficial to extensor retinaculum

Question 6

Differentiation between isolated EDM rupture vs. EDM-EDC rupture in RA

Answer 6

Isolated EDM rupture = 40deg extension lag

EDM-EDC rupture = complete drop finger

Question 7

Management of drop finger due to extensor tendon rupture in RA

Answer 7

1. LF only = RF-LF tenodesis or EIP to LF transfer
2. RF and LF = MF-RF tenodesis and EIP to LF transfer
3. MF, RF and LF = IF-MF tenodesis and RF FDS transfer to RF-LF tenodesis
4. IF, MF, RF and LF = MF FDS transfer to IF-MF tenodesis and RF FDS transfer to RF-LF tenodesis

Question 8

Management of extensor tendon rupture and wrist arthritis in RA

Answer 8

Wrist arthrodesis

ECRB and ECRL can be used as donors for tendon transfer

Question 9

Management of extensor tendon rupture and MCPJ arthritis in RA

Answer 9

Staged procedure
Stage 1 = MCPJ arthroplasty and dynamic splinting to restore motion
Stage 2 = tenodesis and/ or transfer to address tendon rupture