ARTHRODESIS
INDICATIONS
 When joint function is limited by pain, deformity, instability or loss of motor control.
 Specific indications include: RA, OA, trauma, paralytic deformities, burn contractures, lesions of flexor or
extensor tendons (mallet, Boutonniere), infections.
 The goal is to attain a solid, painless joint in a functional position in as short a time as possible (Moberg).
 In the finger, usually reserved for the DIP or PIP, rarely for the MCP (arthroplasty preferred).
 In the Th, the MCP joint may be fused for hyperextension associated with ulnar n paresis or for
hyperflexion deformities. The CMC is frequently fused for OA, especially in labourers who require
power. Stiffness of the other Th joints, especially the MCP and the basal carpal joints may be a C/I to
fusion and prompt one to do arthroplasty instead.
POSITION OF FUSION
 Individual requirements of the particular patient take precedence to any prescribed angle.
 In general however, the angles recommended are:
Th
I
M
R
L
MCP
20o
25o
30o
35o
40o
PIP
15o
20-40o
30-45o
40-50o
50-55o
20o
20o
20o
20o
DIP
METHODS OF FUSION
 Dorsal longitudinal or curvilinear incisions. Methods in which articular surfaces are cut flat to preplanned angles are problematic in that no final bone adjustment is possible without further bony resection.
 A “cup and cone” arthrodesis allows better angle adjustment and greater contact surface for bony healing.
Fixation techniques
1.
Longitudinal K wire (0.045 of an inch)
2.
Crossed K wires
3.
Interosseous wiring (Box wiring)
4.
Compression plate
5.
K wire external fixator devices
6.
Intramedullary bone graft
7.
Tension band wiring
COMPLICATIONS
1. Malpositions, especially rotational deformities. Also angulations.
2. Malunions, delayed unions, non unions
3. Neurovascular injury
4. Pin tract sepsis
WRIST ARTHRODESIS
Indications
 Same indications: pain, instability, deformity. Specifically: RA, OA, paralysis, spasticity, arthrogryposis.
Approaches
1. Usually dorsal. Linear incision from over MF MC to proximal radius. Carpals approached between the
3rd (EPL) and 4th (EDC) compartments. Some advocate other approaches if extensive scarring or fear of
causing extensor adhesions.
2. Lateral ulnar approach
3. Radial approach from proximal to radial styloid to over IF MC. Carpals approached between 1 st and 2nd
extensor compartments. Superficial br of the radial n protected.
Position
 10-15o of dorsiflexion and 5o of ulnar deviation but influenced by individual needs of the patient.
 For RA patients, fixation in neutral is best for personal hygiene.
 If both wrists are to be fused, the dominant one can be fused in 10-15o of dorsiflexion and the other in
neutral, both in 5o of ulnar deviation.
 If marked flexion deformity, proximal row carpectomy may be required.
Fixation
1. K wires
2. Bone grafts
3. Intramedullary rods
4. Compression plating
 Time to fusion is usually 12 weeks.
Complications
 Difficult procedure with significant morbidity. Non union or pseudoarthrosis is a common Cx (15%).
 Problems with wound healing and skin necrosis are also common.
 Neurological injury: Superficial br of radial nerve mRin neuroma. Neuropraxia of median n can occur.
 Other Cx: infection, loss of position, iliac crest bone graft donor site problems, etc.
LIMITED WRIST ARTHRODESIS
 An alternative to full wrist fusion in selected cases. Fusion is limited to areas of disease, allowing
preservation of some function albeit with a reduced ROM.
Indications
1. For painful arthritis between limited joint surfaces
2. For failed ligament reconstructions
3. For stabilisation of carpal collapse deformities
4. In combination with arthroplasities when carpal instability is present
Considerations
 Proper pre-op evaluation must confirm that the disease process is limited.
 Cancellous bone should be used.
 K wires should be used to hold the fixation.
 Non union can cause exacerbation of pain.
 The arthrodesis must not place undue stress on the other joints.
Specific types
1. Scapho-trapezial-trapezoid fusion (S-T-T) - Triscaphoid fusion. The most common limited wrist fusion.
2. Capitate-lunate arthrodesis: Degenerative joint disease, non union of capitate/lunate #s and Kienbock’s.
3. Many others exist:
a) Scapho-capitate: for scaphoid instability with or without a DISI deformity.
b) Four-corner arthrodesis (capito-hamate-luno-triquetral): for the SLAC (scapho-lunate advanced
collapse) wrist which occurs following scaphoid non union and rotatory subluxation of the wrist.
Scaphoid removed and 4 corner arthrodesis done.
c) Scapho-lunate: for scapho-lunate instability. Unpopular option because fusion difficult to achieve.
d) Radio-scapho-lunate: for RA
e) Radio-lunate: prevents ulnar translocation in RA.
f) Luno-triquetral