Factors affecting the outcome in 50 cases of scaphoid nonunion treated with Herbert screw fixation.

Our experience in the treatment of 50 scaphoid nonunions treated with Herbert screw fixation is reviewed. Success rates fell off as the duration of nonunion before treatment increased. However, this appeared to be related to the increased incidence of avascular necrosis with time rather than simply the factor of time alone. In this series the major adverse determinants for outcome were avascular necrosis and a history of previous surgery for nonunion. Failure to graft in a selected group with an intact cartilaginous envelope or a stable firm fibrous union did not affect results. The heterogeneous nature of any series of scaphoid nonunions is emphasized and the difficulties in comparing results with cohorts unmatched for the various adverse factors discussed is stressed.