Management of non-unions with mono-lateral external fixation

We reviewed a cohort of 107 patients (110 long bone segments) with fracture non-union, treated by mono-lateral external fixation in Sheffield between 1987 and 1996. There were 83 males and 24 females with a mean age of 36 years. Sixty-seven patients had high-energy injuries and there were 56 open fractures. There were 60 tibiae, 38 femora and the rest were upper limb long bones with a mean of 3.2 previous procedures. The mean duration of non-union was 23.4 months (range 3–123). There were 61 mono-focal procedures with 41 supported in neutralisation, 20 in compression and three in distraction. There were 49 bifocal procedures (33 compression distraction and 16 bone transport). Seventy-one segments required a bone graft. The success rate using the initial fixator was 90%. Seven patients required further fixation to achieve clinical and radiological union, bringing the healing rate to 95.5% (total n=105). There were five amputations, all in smokers and three of them were directly related to vascular failure. The mean hospital stay was 21 days and the mean number of operations per patients was 2.55. The mean time to bony union was 12.69 months (range 2.5–64). The mean length gain was 4.5 cm (range 1.5–12 cm), the mean angular correction achieved was 12° (range 2–39°). The bony and functional results were assessed at the end of treatment by system described by Paley and Catagni (JBJS 77A, 1995). Conclusions: Mono-lateral external fixation can provide stable fixation for the treatment of established non-unions. The fracture environment may be carefully controlled and angulation and length corrected simultaneously. Interestingly 11 out of 12 problem cases were in smokers.