The treatment of pseudoarthrosis of the scaphoid by bone grafting and three methods of internal fixation.

OBJECTIVES

To measure the rate of union in patients with pseudoarthosis of the scaphoid, treated with trapezoidal bone grafting as outlined by Fernandez and 1 of 3 methods of internal fixation and to compare unions versus nonunions and potential predictors of union to determine if associations exist.

DESIGN

A retrospective radiologic study of scaphoid pseudoarthroses.

SETTING

Division of Orthopedic Surgery, Ottawa Hospital, General Site, a tertiary care facility.

PATIENTS: Thirty-four patients with nonunion of scaphoid fractures, treated between 1990 and 1997, with an average follow-up of 19.8 months.

INTERVENTIONS: Trapezoidal bone grafting and internal fixation with Kirschner (K) wires, an AO cannulated screw or a Herbert screw.

OUTCOME MEASURES: The time to union of scaphoid pseudoarthroses and predictors of union, including the classification, location of pseudoarthrosis, type of internal fixation and length of bone graft.

RESULTS

The results showed a correlation between the classification and location of the fracture as determined radiologically, and the outcome. There was no correlation between the type of internal fixation used and the outcome, or between the length of the bone graft and the outcome. Twenty-three patients had radiologically demonstrated union after a mean time of 8.2 months; 16 of 24 patients achieved successful union when treated with K-wire implants, after a mean time of 7.2 months.

CONCLUSIONS

Trapezoidal bone grafting and internal fixation with K wires is a practical technique, classification and location of the fracture notwithstanding. Time to union is long, and the results may be unpredictable. Use of K wires for internal fixation presents the clinician with an alternative to fixation with either the AO cannulated screw or the Herbert screw, and has the advantages of cost, ease of insertion and accessibility. This method may therefore be the treatment of choice in developing countries. Resection of the area of pseudoarthrosis must include all fibrous tissue and sclerotic bone. The length of graft, within the parameters of this study, did not affect the outcome.