Abstract
Conservative management remains the gold standard for many fractures of the humeral diaphysis with union rates of over 90% often quoted. Success with closed management however is not universal.
Phase 1
A retrospective review of all conservatively managed fractures between 2001 and 2005 was undertaken to investigate a suspected high non-union rate and identify possible causes. The overall non-union rate was 39.2% (11 of 28 cases). There was no difference in axial distraction at presentation, however following application of cast there was significantly more distraction in the non-union group (1.2 v 5.09mm, p<0.01).
Changes to practise
All humeral fractures were admitted, lightweight U-slabs were applied by a technician, distraction was avoided, patients abstained from NSAIDS, consultant reviewed radiographs before discharge and patients were converted early to functional brace.
Phase 2
Prospective collection of data over the following two year period showed a decrease in the amount of distraction when first placed in cast (2.73 v 0.74, p<0.05), a reduction in NSAID use (89% v 38%, p<0.01) and earlier conversion to brace (37 v 20 days p<0.01). These changes to practise led to a dramatic reduction in non-union rate from 39.2% to 4.9% (p<0.01).
Conclusion
Over-distraction at first application of cast is a causal factor in the development of non-union. Lightweight cast, avoidance of distraction, abstinence from NSAIDS and early conversion to functional brace is recommended. The initial surgical management of the patient who displays evidence of distraction will prevent evolution of non-union with conservative management. This will avoid lengthy delays in the treatment of the non-union and also help to prevent secondary stiffness in adjacent joints and disuse osteopenia.
