Assessment of the stage of nonunion relies on standard X-rays, CT-scan, and possibly MRI when suspecting a necrosis. Treatment choices will differ according to each stage.

In Alnot?s stage I (Herbert?s type D1), simple screw fixation is often sufficient because the bone stock of the scaphoid is preserved.

In Alnot?s stage IIA (Herbert?s type D3), it may be necessary to add a vascularized bone graft to a stable bone fixation.

In Alnot?s stage IIB (Herbert?s type D3), the intracarpal dissociation must be corrected by means of a bone graft, vascularized or not, in order to re-establish scaphoid height, associated with a stable bone fixation.

In Alnot?s stage IIIA, one may use the same treatment as in stage IIB, together with radial styloidectomy, provided that arthritis is limited to the radio-styloid area. If arthritis involves the whole of the scaphoid fossa of the radius, proximal row carpectomy represents a satisfactory option as long as the proximal pole of the capitate and the radial surface of the lunate are intact.

In stage IIIB, arthritis involves the midcarpal joint, requiring palliative treatment such as scaphoidectomy associated with four corner fusion.

I stage IVA, without arthritis, it is possible to reconstruct the scaphoid by means of a vascularized bone graft. In stage IVB, with arthritis, the treatment is the same as in stage IIIB.

The Matti-Russe bone graft is the most popular technique, consisting in a cortico-cancellous bone graft embedded into the scaphoid, which has been emptied out beforehand.

This procedure requires both regional and general anesthesia because of the bone graft from the iliac crest. The wrist approach is a classical Henry anterior approach. The FCU tendon is identified and reflected ulnarwards while the radial artery is reflected radialwards. The joint capsule is incised longitudinally down to the scaphoid tubercle. The anterior radioscapholunate ligament is incised and will be repaired at the end of the procedure. The scaphoid is reduced with the help of a bone chisel. Interfragmentary fibrosis is carefully curetted and the nonunion site is freshened. A cavity is created in the proximal and distal fragments, and the necrotic cancellous bone is excised. The anterior window is widened at the level of the anterior osteochondral aspect of the scaphoid. The medial, lateral, and dorsal aspects must be preserved in order to determine proper reduction of the two fragments after the scaphoid height has been restored. If there is any doubt regarding vascular supply of the two fragments, the tourniquet can be temporarily deflated in order to assess it. The palmar flexion deformity can be usually be corrected by positioning the wrist in maximal extension and ulnar deviation. When necessary, two temporary K-wires will maintain the reduction: one between the proximal pole of the scaphoid and the lunate, and one between the distal tubercle and the capitate.

The bone graft is harvested at the iliac crest under general anesthesia. The femoro-cutaneous nerve must be carefully preserved. Harvesting is performed at the level of the lateral part of the iliac crest, taking into account the natural curvature of the crest, which often matches the anterior curvature of the scaphoid. Complementary cancellous bone may be harvested if needed. The Matti-Russe graft is then introduced in the prepared cavity of the scaphoid, and forcefully embedded in order to obtain primary stability. However, it is advised to add a bone fixation with two k-wires in order to stabilize the graft. The radioscapholunate and the anterior capsule are then closed with non-absorbable sutures, and the skin is closed over a suction drain. Immobilization is performed with a simple plaster splint. The iliac crest is closed stepwise over a non-suction drain. Injection of local anesthetics around the periosteum and the soft tissues of the iliac area insures a pain-free postoperative period. The K-wires are removed after union has been obtained, usually at 3 months postoperatively.

This technique, described by Fisk, was modified by Fernandez. Patients are operated supine with the arm abducted and a pneumatic tourniquet. The contralateral pelvis is elevated on a cushion in order to access the iliac crest. The forearm is positioned in supination with the wrist in extension in order to set the position of the carpus. The surgery is performed under regional anesthesia, complemented with general anesthesia at the time of iliac bone harvesting. The volar approach is centered on the radial aspect of the flexor carpi radialis (FCR) tendon, extended towards the scaphoid tubercle with a bayonet-type incision. The FCR tendon is approached on its radial side and reflected ulnarwards. The radial artery is identified and reflected radialwards. The capsule and the radioscaphocapitate ligament are incised. The nonunion site is best exposed by bringing the wrist in full extension. The radioscaphoid and scaphocapitate joints are cleared of all fibrous tissue in order to expose the medial and lateral aspects of the scaphoid properly. Reduction of the scaphoid flexion deformity is performed with a bone chisel while maintaining the wrist in maximum extension. If the fragments are highly unstable, they can be temporarily fixed to the adjacent carpal bones with K-wires. The margins of the nonunion are freshened with a curette or a fine chisel. Both fragments can also be perforated with a fine K-wire.

A cortico-cancellous monobloc trapezoidal graft is harvested with a chisel at the level of the iliac crest. The graft is subsequently carved in order to fill the bone loss completely while maintaining the shape and height of the scaphoid once inserted. A K-wire maintains the reconstruction. Permanent bone fixation is performed with a compression cannulated screw which will further embed the graft between the two fragments. If the fragments are too small for screw fixation, it is preferable to use two or three K-wires rather than risking a difficult and dangerous screwing. Adequate reconstruction and bone fixation are checked with intraoperative imaging (fluoroscopy). The radioscaphocapitate ligament and the volar capsule are carefully sutured with absorbable sutures. A temporary compressive dressing and cast are replaced after a few days with a removable anterior splint, until final bone healing.

The use of a bone graft together with bone fixation has shown to be effective, allowing bone healing to be more frequent than when they are used separately. Because of the technical challenge, vascularized bone graft was formerly restricted to cases of failure of the classical techniques.

In 1965, Judet and Roy Camille were the first to suggest the use of a vascularized bone graft from the anterior aspect of the radius for scaphoid nonunion. The graft was vascularized by muscle fibers from the pronator quadratus (coming from the anterior transverse carpal artery).

Several vascularized grafts have been described, with favorable results. We recommend the modification of the volar graft described by Robert Judet. It is harvested from the anterior aspect of the radius, vascularized by the anterior transverse carpal artery, the pedicle of which is long enough to reach the scaphoid without any undue tension. The principle of this bone graft is based on the presence of an anastomotic arterial network on the anterior aspect of the distal radius and ulna.

Technique

The scaphoid and radius are exposed in the interval between the radial artery and the tendon of the flexor carpi radialis. With the wrist in extension and ulnar deviation, the anterior capsule is reflected, exposing the scaphoid and distal margin of the radius. Fibrous tissue and devascularized bone are removed from the site of the nonunion using a small curved curette. Restoring the scaphoid to its appropriate length is facilitated by traction on the thumb and by using a narrow osteotome to separate the 2 poles of the scaphoid at the nonunion site. Intraoperative radiographs can help confirm the adequacy of the reduction. The dimensions of the defect in the scaphoid are measured while the osteotome maintains separation of the fracture fragments. If necessary, the provisional reduction can be maintained by placing a pin through the distal pole of the scaphoid into the capitate and a second pin through the proximal pole into the lunate.

Dissection of small arteries may result in damage to the vessel unless it is harvested with a cuff of adjacent tissue. The volar carpal artery has a predictable location between the periosteum of the radius and distal margin of the pronator quadratus. The fascia and muscle of the pronator quadratus are incised 1 cm from its distal margin along the full width of the muscle. The periosteum is incised along the distal and proximal margins of this 1 cm strip of fascia and muscle. The radial half of this strip is elevated, with its periosteum off the palmar cortex of the radius, by using a combination of scalpel and osteotome. Dimensions of the graft are marked on the radius, and the graft is harvested using 10-mm osteotomes. The axes of the osteotome are oblique on the distal and proximal part of the graft to create a pyramid-shaped graft. The pedicle and bone are elevated using two 5 mm osteotomes. The graft and its pedicle then are dissected to the origin of the volar carpal artery. The most lateral attachments of the pronator quadratus fascia can be divided without hesitation to create a 4 to 5 cm pedicle.

The scaphoid is stabilized with a screw inserted anteriorly and directed distal to proximal. The screw is inserted as dorsal as possible to minimize interfering with placement of the graft. We also avoid the scaphotrapezial joint to avoid future discomfort.

The bone graft is placed to fill the defect on the palmar aspect of the scaphoid. If the surgeon is successful in matching the graft to the defect, no additional graft is necessary. Small residual defects can be filled with cancellous bone from the distal radius. The graft can be stabilized by tightening the screw or with a pin inserted from the distal tubercle into the graft. This pin should be parallel to the screw to avoid damaging the vascular pedicle.

The capsule, particularly the radioscaphocapitate ligament, is repaired with care to avoid compressing the pedicle. The skin is closed over a suction drain. The wrist is immobilized in a palmar short-arm splint with the wrist in about 40° of extension. If a pin is used to stabilize the graft, it is removed in 3 weeks. Wrist immobilization is continued until there is radiographic and clinical evidence of union.

The treatment of scaphoid nonunions is difficult and controversial. Indications depend on the stage of the nonunion, the age of the patient, and the experience of the surgeon.

Screw fixation is a good technique in tight nonunions without bone loss. Bone graft is mandatory whenever there is loss of bone substance with or without scaphoid deformity.

Corticocancellous bone graft according to ?Matti-Russe? or ?Fisk-Fernandez? is a food technique with satisfactory results, provided one follows the following rules :

• Iliac bone graft
• Good stabilization of the graft and the scaphoid with stable bone fixation
• Wrist immobilization until solid union, which is usually quite long (3 months)

Vascularized bone graft is a good option in scaphoid bone los. It has been advocated initially for the treatment of proximal pole necrosis, and in cases of failure of the classical techniques.

The bone graft vascularized by the anterior transverse carpal artery allows for graft harvest and treatment of the nonunion through a single anterior approach, thus avoiding the need for general anesthesia and inpatient treatment. Due to the quality of the functional results and the speed of bone union, we now advocate for vascularized bone graft as a primary treatment of scaphoid nonunions.