Hand iSAWE 1

Causes of dropped fingers

1. Ext tendon rupture (Vaughan Jackson synd) (synovitis)
2. Extensor tendon subluxation (deformity)
3. MCPJ subluxation (reducible?)
4. Trigger finger (fixed)
5. PIN palsy from radiohumeral synovitis (sensation)

Extensor tendon rupture

Assoc tendon ruptures addressed at time of synovectomy.

• Isolated LF rupture à suturing the distal stumps to the adjacent RF EDC
• If RF & LF involved à they are sutured to the middle EDC & reinforced w/ EIP
• Triple & quadruple ruptures require FDS transfers
• EPL rupture is treated with EIP transfer

Volar subluxation/dislocation at MCPJ

Synovectomy of MCP and PIPJ

• Can be done for pain relief but synovitis tends to recur.
• In MCPJ synovectomy is usually combined w/
  • ulnar intrinsic release &
  • radial relocation of ulnarly subluxed extensor tendons.

MCPJ arthroplasty
Silicon Swanson arthroplasty is a good operation. 

• provides excellent pain relief. 
• not much ↑ in ROM, w/ the range moving into extension. 
• Not help much with ↑ing grip strength. 
• help the patient to open her hand.
• During arthroplasty, ulnar subluxation of extensor tendons is addressed.
• The long term motion at MCPJ post arthroplasty is ~40°. 
• Implant fracture occurs in up to 25%, and there can be implant subsidence and bone resorption.

Flexor tenosynovitis/trigger finger

Flexor tenosynovectomy of the finger

• Dx is made by noting that there is less active flexion than passive flexion. 
• Tenosynovectomy provides good pain relief & functional improvement but recurrence often occurs.
• important to preserve A1 pulley in addition to A2 & A4 pulleys, or progressive ulnar drift will occur. 
• Trigger finger may be addressed by division and excision of one of the slips of FDS.
• Flexor tendon rupture is dealt with as follows:
• Isolated FDP rupture à fuse DIPJ & perform synovectomy of FDS.
• FDP & FDS rupture in finger à tendon graft
• FDP & FDS rupture in palm à transfer adjacent FDS to FDP stump
• If both jts are poor à arthrodese both joints
• FPL rupture à interposition graft, FDS tendon transfer or fusion.

Trigger finger

• Based on length of symptoms (< or > 6 months) and whether disease is nodular or diffuse.
• If <6 months & nodular, reasonable to attempt corticosteroid injection.
• If >6 months & nodular, percutaneous release.
• If diffuse, open release.

PIN palsy from synovitis

• will have tenodesis extension intact on flexion of the wrist
• Possible sites of compression include:
• Thickened fascial tissue superficial to radiocapitellar jt
• Leash of vessels from radial recurrent vessels (= Leash of Henry)
• Fibrous edge of ECRB
• Arcade of Frohse
• Distal edge of supinator

Treatment

• Surgical exploration should be undertaken within 12 weeks of onset.
• Ant (modified Henry) approach will give good exposure to the nerve as it enters arcade of Frohse. 
  • incision from this begins 6 cm above lat humeral condyle, runs down lateral to biceps & then down the medial border of BR. 
  • radial nerve is found proximally in interval b/w brachialis & BR & traced distally. 
  • Fibrous bands overlying PIN & the fibrous edge of ECRB are divided; the leash of Henry is ligated & the arcade of Frohse is sectioned longitudinally.