Abstract
Purpose of the study:
To determine the outcomes of cases converted from an external fixator to an internal fixation device in the management of limb reconstructions and deformity corrections.
Method:
A retrospective review of 18 patients, that underwent a conversion procedure to internal fixation following long term external fixation use, was done. This comprised 24 limbs. Inclusion criteria: All cases of long term external fixator use converted to internal fixation over a 5 year period. Average external fixation time, pin site care, conversion timing, surgical device used as well as outcome were documented.
Results:
The mean treatment time in an external fixator was 185 days (61–370). The reasons for conversion included patient dissatisfaction, pin tract sepsis and a refracture. The conversion procedures included 8 intramedullary nail fixations and 16 plate and screw fixations. An acute conversion was identified as an internal fixation that was done in the same sitting as external fixator removal. A delayed conversion was any internal stabilisation that was done thereafter. In total, the complication rate associated with conversion to internal fixation following long term external fixation was 25%, mainly due to persistent non-union or sepsis.
In the 8 conversions to intramedullary nails, 7 were acute: 4 had good outcomes with sepsis free union being achieved. 3 had poorer outcomes with a non-union and 2 amputations being documented. The single delayed nailing achieved union.
In the 16 conversions to plate fixation, 13 achieved union. 10 were acute conversions and 3 were delayed. The remaining 3 that developed complications included 2 acute conversions with septic non-unions and a single delayed conversion which resulted in sepsis.
Conclusion:
Conversion of an external fixator to an internal fixator in a non-acute reconstructive setting has a 75% success rate. In the acute conversion group (19 cases), plate and screw fixation had a superior outcome. In the delayed conversion group (5 cases), intramedullary fixation was favoured.
