Patients treated for nonunions with plate and screw fixation and adjunctive locking nuts

Locking nuts were used as an adjunct to plate fixation in 48 procedures in 44 patients. All the procedures were done by one surgeon during a 4-year period. The patients in this study were treated for nonunion or malunion and thus had difficult technical problems, such as cortical defects or holes left from previous hardware. The use of standard implants were generally unreliable for additional fixation. The locking nuts were used as a cortical substitute in 26 instances, to create a fixed angle relationship between the plate and the screw in 14 instances, to elevate the plate off the bone to help increase vascularity in five instances, and to increase purchase in severely osteoporotic bone in three instances. Complete followup was obtained on 43 of the 44 patients. Forty of the 43 patients achieved complete union after their reconstructive procedure. Three patients had continued nonunions with eventual hardware failure and required reoperation. The use of the locking nuts enabled the surgeons to obtain stable fixation at the time of reoperation with eventual union of all of the ununited bones. The success of the use of this implant is best gauged by the fact that the surgeon could place screws effectively where cortical defects existed, allow improved purchase in osteoporotic bone, and create a fixed angle plate screw relationship that would have been difficult to do without the locking nuts.