Wrist Arthrodesis, Four Corner Arthrodesis and Scapholunate Arthrodesis

Wrist arthrodesis is a salvage procedure to provide the patient with pain free immobile wrist in maximum functional position. Arthrodesis means fusion of the bones.

After arthrodesis or fusion, motion between worn joints is eliminated and so is pain.

Indications

As noted before, wrist joint is a salvage procedure. Because it needs to sacrifice motion, other options of treatment must be considered and discussed with patient wherever feasible.

-Wrist arthropathy from any cause where pain is not responding to nonoperative measures. Causes of wrist arthropathy may be

• Trauma
• Rheumatoid arthritis
• Crystalline arthropathy
• Carpal instability
• Tumors
• Septic arthritis
• Mechanical overuse
• Scaphoid nonunion

– For stabilization of the wrist when combined with tendon transfers

– Correction of wrist deformities in patients with spastic hemiplegia

– Salvage of unsuccessful wrist arthroplasty

– Previous, unsuccessful, more limited arthrodesis

– Reconstruction of wrist in

• Segmental tumor resection
• Infection
• Traumatic bone loss of the distal radius and carpus

Procedure of Arthrodesis

Using a dorsal incision and bone graft following joints are fused

• Radioscaphoid
• Radiolunate
• Scaphocapitate
• Capitate-lunate
• Capito-trapezoid
• Third carpometacarpal joints.

Compression plate is used to fix the fusion and spans from  third metacarpal to distal radius. Wris is generally fused in 10 degrees of dorsiflexion.

Lunotriquetral, capitate-hamate, triquetrum-hamate [ulnar sided joints] are fixed if there is significant arthrits in these joints at time of operation.

Contraindications

• Quadriparetics who use modified grasp and transfer techniques
• Major sensory deprivation in the hand

Complications

• Extensor tendon adhesions
• Plate tenderness forcing  implant removal.
• Pseudarthrosis- A failure of fusion resulting in false joint
• Neuroma
• Fracture of healed fusion.
• Carpal tunnel syndrome
• Reflex sympathetic dystrophy
• Poor wound Healing
• Persistent unexplained pain

Outcome

Wrist arthrodesis provides good pain relief  and correction of deformity. Patients can perform most of the activities of daily living. Problem is experienced in negotiating hand in tight spaces and executing some positions of the hand.

Four Corner Arthrodesis of The Wrist

Four corner arthrodesis involves excision of scaphoid and fusion of the remaining wrist bones in neutral alignment. It is motion preserving limited arthrodesis and provides pain relief and improved grip strength.

This four corner arthrodesis is based on the principle that the radiolunate articulation is often spared from degenerative changes from conditions.

Indications

• SLAC wrist
• Chronic dynamic carpal instability
• Chronic perilunar instability not amenable to soft tissue surgery

Contraindications

• Ulnar Translocation
• Radiolunate arthritis

Procedure

The surgical procedure is typically performed under regional anesthesia. A dorsal longitudinal incision is centered over the proximal carpal row.

The joint capsule is opened individual carpal articulations are exposed.  The scaphoid is identified and excised in most of the cases.

Reduction of the collapse deformity to realign the midcarpal joint is critical to the success of the procedure. The lunotriquetral relationship is reduced  and secured with  Kirschner wires.

The fusion surfaces between the lunate, capitate, hamate, and triquetrum are then denuded down to cancellous bone..

The graft from scaphoid or distal radius is meticulously packed into the fusion sites. The proximal carpal row is reduced and stabilized with either multiple Kirschner wires or cannulated screws.

After surgery, patients are placed in a compressive dressing with an internal short arm splint. Digital motion is encouraged immediately after the effect of anesthesia wanes off.

At 10 to 14 days postoperatively, a short arm cast is applied in those individuals treated with pins alone. These are typically removed at approximately 8 weeks postoperatively, at which time therapy is begun.

Complications

Following complications have been reported with four corner arthrodesis.

• The most common complication after four-corner fusion is dorsal radiocarpal impingement in wrist extension. This occurs secondary to inadequate reduction of the capitolunate relationship
• Reflex sympathetic dystrophy
• Infections
• Nonunions
• DeQuervain’s tenosynovitis

Non union is very rare in four corner arthrodesis. There is a reported failure rate of 2%.

Radioscapholunate Arthrodesis

Radioscpholunate arthrodesis is done in selected patients who would not accept loss of motion that accompanies wrist arthrodesis. It is based on the observation that most activities of daily living can be accomplished with wrist motion in the range of 10° flexion, 35° extension, 10° radial deviation, and 15° ulnar deviation.

Wrist arthroplasty can provide pain free mobiity but is not a good option in persons with high physical demands.

As the name indicates,it is an arthrodesis of radius, lunate and scaphoid.

Indications of Radioscapholunate Arthrodesis

This arthrodesis is done in patients with radiocarpal joint degeneration which can result from

• Posttraumatic arthritis
• Inflammatory arthritis
• Osteoarthritis
•  Scapholunate advanced collapse

Procedure

The procedure involves exposure of the opposing articular surfaces of the scaphoid, lunate, and distal radius by dorsal approach and cancellous bone graft is placed after removal of the articular cartilage. Few surgeons use kwires , screws or plate for fixation.

Postoperative immobilization for approximately 8 weeks is done. A splint is used for an extended period.

Fusion may take up to three months.

Outcome

Reported wrist motion after the procedure are in range of 23° flexion, 24° extension, 9° radial deviation, and 16° ulnar deviation.

Complications

• Painful wrist instability
• Arthritis

Scaphoid fractures, and postoperative deterioration of the midcarpal joint have been reported.