Radioscapholunate arthrodesis is a type of partial arthrodesis of the wrist which preserves some of the motion in the wrist joint.
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 mobility but is not a good option in persons with high physical demands.
As the name indicates, it is arthrodesis of radius, lunate and scaphoid.
This fusion reliably produces pain relief while maintaining some wrist motion.
ROM generally is 33–40% of normal and there is a high rate of degenerative midcarpal arthritis.
The range of motion improves with excision of the distal pole of the scaphoid and/or triquetrum.
With excision of the triquetrum, ulnar deviation improves.
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
- Kienbock disease
Procedure
A midline dorsal approach is used. Care is taken to protect the branches of the superficial radial nerve is used. The midcarpal joint is inspected. If the midcarpal joint is functional, then the RSL fusion is performed.
The extensor retinaculum is incised over the third extensor compartment Tubercle of Lister can be taken as a landmark to guide.
Extensor pollicis longus is retracted radially. Carpus is exposed by developing full-thickness capsular flaps.
The distal pole of the scaphoid and the triquetrum are excised. The excised bone is kept for later use as a bone graft in the procedure.
Following articular surfaces are prepared for fusion by denuding –
- The proximal scaphoid
- The proximal lunate
- The distal radius
Bleeding cancellous bone is a sign of sufficient preparation.
The scapholunate joint is then reduced and held with two K-wires.
The bone graft is packed in the radioscapholunate interval and fixation is done.io
For fixation following options of implants are available
- K-wire fixation
- Plate and screws
- Herbert screws
- Cannulated screws
- Staples
The fixation devices which provide more stability allow early mobilization.
For a better functional outcome, the lunate and scaphoid are placed in 15° of extension. This makes motion arc more functional.
The position of wrist is confirmed by fluoroscopy.
The wound is closed in layers and the wrist is immobilized in a plaster slab for 6 weeks.
A splint can be used for an extended period.
Fusion may take up to three months.
Benefits of Resection of Distal scaphoid pole
- Range of motion is increased – flexion and radial deviation
- Union rate improves
- Decreases the incidence of development of degenerative midcarpal arthritis
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.
References
- Bain G I, Ondimu P, Hallam P, Ashwood N. Radioscapholunate arthrodesis—a prospective study. Hand Surg. 2009;14(2–3):73–82.
- Garcia-Elias M, Lluch A, Ferreres A, Papini-Zorli I, Rahimtoola Z O. Treatment of radiocarpal degenerative osteoarthritis by radioscapholunate arthrodesis and distal scaphoidectomy. J Hand Surg Am. 2005;30(1):8–15.
- Sturzenegger M, Büchler U. Radio-scapho-lunate partial wrist arthrodesis following comminuted fractures of the distal radius. Ann Chir Main Memb Super. 1991;10(3):207–216.
