CHAPTER 12: HAND - REPLANT, THUMB RECONSTRUCTION AND FINGERTIP INJURIES Flashcards
Who were the pioneers of replantation?
1st successful arm: Malt 1964 (Boston)
incompletely severed digits: Kleinert Kasdan 1965
1st successful digital replant: Komatsu & Tamai 1968
Define:
- Replantation
- Revascularisation
- Macroreplantation
- Microreplantation
- Replantation = reattachment of totally amputated parts.
- Revascularisation = repair of incomplete amputations.
- Macroreplantation
∘ amputated part contains muscle, which necroses after 6 hours of warm ischaemia or 12 hours of cold ischaemia. - Microreplantation
∘ digits are more resistant to ischaemia (at least 12 hours of warm ischaemia or 24 hours of cold ischaemia).
What are the pertinent points in history?
- age, hand dominance, occupation, hobbies
- pre-existing hand problems
- mechanism of injury
- ischaemia time, storage of amputated part
- smoker?
- tetanus status
What are the contraindications of replant?
Absolute
- life-threatening concomitant injuries
- multi-level injury
- severe premorbid illness
Relative
- single digit amputations,
- zone II,
- inadequate venous anastomoses (need 4mm proximal to nail fold)
- degloved
- avulsion of tendons, nerves, vessels (‘red streak sign’ = bruising over NV pedicle, ‘ribbon sign’ = corkscrew appearance of vessels).
- extreme contamination / crush
- warm ischaemia time (digit >12hrs, arm >6hrs)
- elderly, micro-arterial disease, heavy smokers, severe systemic / psychiatric disease
What are the indications for replant?
- Thumb
- Child
- Multiple digits
- Partial / whole hand
- Wrist, forearm, elbow and above elbow
- Single digit distal to FDS insertion (zone 1 better outcome than zone 2)
- Patients who ‘must’ have a 10-digit hand, e.g. musicians.
What is the arterial supply to the hand?
Ulnar - superficial palmar arch - common - radial and ulnar digital arteries
Radial - deep palmar arch - deep to flexor tendons
UDN dominant - thumb, index, middle
RDN dominant - ring, little
Arterial grafts may be needed for: long revasc time (e.g. radial artery to thumb)
What classifications do you know for ring avulsion injuries?
Urbaniak 1981
Class 1 - no vascular compromise, with soft tissue injury
Class 2 - vasc compromise, microvascular reconstruction will restore circulation and function. (ABC added by others)
A - digital arteries only
B - arteries + tendon, bone, nerve
C - veins only
Class 3 - complete degloving / amputation, circumferential laceration (replant unlikely to be successful)
What is Simon Kay’s classification of ring avulsion injuries?
Kay et al., JHS 1989, 14A, 204-13
I Circulation adequate, without skeletal injury
II Circulation inadequate, without skeletal injury
IIA Arterial circulation inadequate only
IIV Venous circulation inadequate only
III Circulation inadequate, with fracture or joint injury
IIIA Arterial circulation inadequate only
IIIV Venous circulation inadequate only
IV Complete amputation
What is noted on examination?
Trauma - ATLS principles
Amputated part - degree of crush / avulsion
X ray - concomitant injuries
Consent for graft harvest (vein, tendon, skin) and terminalisation
What can be done if there are no artery / vein available?
What other procedures may be considered?
If no suitable artery available:
• Interposition vein grafts (e.g. volar wrist) or vessel transposition from adjacent finger.
• Grafts can be placed extra-anatomically to radial artery at the wrist.
• If no suitable dorsal veins available:
1. Repair any volar veins.
2. Anastomosing a digital artery (which has backflow) to a vein, creating an arteriovenous
fistula.
3. Remove nail plate and scrape sterile matrix to encourage bleeding with heparin-soaked gauze.
4. Periungal incision and topical heparin.
5. Medical leeches.
Consider: carpal tunnel decompression, soft tissue cover, nerve, vein grafts.
Major limb - fasciotomies, proximal carpectomy (hand)
What are the special considerations in macro replantation?
- Temporary vascular shunt, such as a Sundt, Pruitt-Inahara or Javid shunt is priority.
- Bone shortening (makes primary vessel and nerve repair easier).
- Fixation of bone
- Definitive arterial repair.
- Allow venous bleeding from amputated part to flush out toxic metabolites (+ blood transfusion).
- Fasciotomies are always indicated.
- Assess for further muscle necrosis within 48–72 hours.
How do you perform a digital replant?
GA, brachial block (vasodilatation and postop analgesia), arm tourniquet, image intensifier, 2 team approach.
Team 1:
- Examine + XR amputated part before pt is GA’d,
- Mid axial incisions, tag NVBs,
- Shorten bone ~5mm, fix with Kwire / IO wires / box 90-90 / miniplates and screws.
Team 2: Debride stump, tag NVBs. Order of repair: Bone extensor flexor digital nerve digital artery digital vein skin cover
Consider: carpal tunnel decompression, soft tissue cover, nerve, vein grafts
Major limb - fasciotomies, proximal carpectomy (hand)
What are the post-operative considerations?
- POSI splint
- warm, wet, pain-free
- elevation 45 degrees
- flap obs
- axillary block (vasodilation and analgesia)
Drugs
- aspirin
- heparin
- antibiotics
- chloropromazine (peripheral vasodilator and sedative)
What are the complications of replant?
failure infection CRPS I pain stiffness swelling cold intolerance atrophy
How do you treat a struggling replant?
Re-explore, vein grafts to artery
Inflow - ensure pt is well filled, analgesed - loosen dressings, If doubt about patency, plan for early exploration 1. Loosen dressing. 2. Warm finger. 3. Remove sutures 4. Use antispasmodic drugs. 5. Improve pain control. 6. Use bupivacaine block (vasodilation). 7. Use heparin.
Outflow
- as above
1. Increase elevation.
2. Loosen dressing and sutures.
3. Use systemic heparin.
4. Remove nail plate with heparin-soaked pledgets.
5. Use leech therapy.
6. Return to theatre.
What are the functions of the thumb?
40% of hand function
- key pinch
- tripod pinch
- power grip
