The causes and treatment for non-infective nonunion of limb long bones

Objective To analyze the causes for non-infective nonunion of limb long bones and to summarize the methods and outcomes of operative treatment of these nonunions.Methods A retrospective study was done of 113 consecutive patients who had been treated operatively at our institution between January 1996 and December 2011 for non-infective nonunion.They were 77 men and 36 women.Their mean age was 40.2 years (range,11 to 73 years).The causes for their nonunions were identified by analyzing their medical files and radiographs,taking into account of the severity of injury,prior treatment,time for first weight-bearing,postoperative functional exercise,general nutrition status.All the patients received removal of the prior fixation implant,recanalization of the medullary cavity,re-fixation and bone grafting.Radiographic follow-ups were made to evaluate the bone healing and limb function.Results The causes for their nonunions were improper manipulation of fixation implants (53 cases),improper selection of fixation device (42 cases),severely damaged blood supply due to surgery (13 cases),bending or breakage of implants (8 cases),unsatisfactory fracture reduction and obvious defects between fragments (7 cases) failure of external plaster fixation (27 cases),severe defects of soft tissue (6 cases),weight-bearing too early (2 cases) and poor systemic conditions (one case).A total of 91 cases (80.5％) were followed for a mean time of 25.2 months (range,12 to 36 months).Bony union was present in all patients after 2 to 13 months (average,5.3 months).No infection,implant failure,pain or instability of fracture ends was observed.Conclusions The iatrogenic factors are the main causes for non-infective nonunion of limb long bones.Operative treatment of these nonunions can lead to satisfactory outcomes if only right fixation implants are chosen and proper bone grafting is performed according to the guidelines for treating nonunions of fracture. Key words: Extremities;  Fractures, ununited;  Fracture fixation;  Treatment failure