A revised protocol for more clearly classifying a nonunion.

Classifying a nonunion solely on the extent of callus formation on a radiograph is insufficient. We have conducted a study with a revised protocol to classify a nonunion more clearly, which uses both radiographic observation and fixation stability. 47 consecutive femoral shaft nonunions were studied using this protocol and 42 nonunions were followed up for at least one year after discovery (range, 1-3 years). 40 nonunions healed after treatment with a union rate of 95.2% (40/42) and a union period of 4.7 plus or minus 0.9 months. The 2 cases of failure were due to implant failure and both healed after reoperation. We recommend this revised protocol as a pretreatment assessment for all nonunions because of its integrity and effectiveness.