[Arthroscopic reconstruction of scaphoid nonunions].

OBJECTIVE: Minimally invasive arthroscopically assisted reconstruction of scaphoid nonunions.

INDICATIONS: Delayed union or nonunion of the scaphoid with sclerosis and with indication for bone transplantation. Limited arthritic changes at the radial styloid.

CONTRAINDICATIONS: Severe humpback deformity with dorsal intercalated segment instability. Midcarpal arthritic changes.

SURGICAL TECHNIQUE: Supine position with the forearm upright and in neutral position, the elbow flexed by 90°, axial traction of 3 to 4 kg. Standard wrist arthroscopy via the 3-4 and the 4-5 portal and the midcarpal joint via the radial and ulnar portal, respectively, with sodium chloride as arthroscopy medium. Change of the optic to the ulnar midcarpal portal and opening of the nonunion with an elevator via the radial midcarpal portal. Resection of the sclerosis with a 3.0 mm burr while irrigating the joint. Harvesting of cancellous bone via the second extensor compartment. On the hand table, closed reduction by joy-stick K‑wires if needed and insertion of K‑wires for the scaphoid screw. Insertion of the screw without entering of the distal thread into the bone. Arthroscopic insertion of the bone transplant by a blunt drill sleeve via the radial portal with steady compression by the obturator. Complete insertion of the screw under arthroscopic control of the compression of the nonunion space with arthroscopic control of stability with the probe.

POSTOPERATIVE MANAGEMENT: Six weeks forearm cast including the thumb metacarpophalangeal joint, radiographic control and non-load bearing movements for two more weeks, CT scan in the oblique sagittal plane after 8 weeks, and increase of load, as well as physiotherapy on demand depending on the radiographic results.

RESULTS: To date, 17 patients with a mean age of the nonunion of 18 months were treated. In 14 patients, bony union was achieved after 8 weeks. In one patient, an extraosseous screw placement was corrected. In another patient with extraosseous screw placement, persisting nonunion was treated with an angular stable plate. One scaphoid demonstrated an asymptomatic tight nonunion after 14 months, while one scaphoid with sclerosis of the proximal pole did not heal.