Management of post-traumatic femoral defects with a monorail external fixator over an intramedullary nail

PURPOSE: The management of limb-length discrepancy secondary to traumatic femoral bone loss poses a unique challenge for surgeons. The Ilizarov technique is popular, but is associated with long external fixator time and many complications. This retrospective study assessed outcomes of post-traumatic femoral defects managed by monorail external fixation over an intramedullary nail. METHODS: Eight patients were included from October 2015 to May 2019 with post-traumatic femoral defects that underwent treatment with monorail fixator-assisted intramedullary nailing. Primary outcome was time to bone union and bone results according to ASAMI classification. Secondary outcomes were lengthening index, consolidation time and index, external fixator index (EFI), time to partial weight bearing(PWB) and full weight bearing (FWB), and complications. Patient reported outcome measures including EQ-5D-5L, SF-36, Oxford knee scores (OKS), and Oxford hip scores (OHS) were recorded after recovery. RESULTS: Mean follow-up time was 227 weeks. Average bone defect size was 9.69 cm. Average consolidation time and index were 11.35 months and 1.24 months/cm, respectively. Mean lengthening and external fixator index were 20.2 days/cm and 23.88 days/cm, respectively. On average, patients achieved FWB and bone union 56.25 weeks and 68.83 weeks after bone transport initiation, respectively. Two patients had docking site non-union, five patients had pin site infections, and two patients had osteomyelitis. EQ-5D-5L and EQ-VAS scores were compared to UK population norms (p = 0.104, p = 0.238, respectively). Average OKS was 32.17 and OHS was 34.00. CONCLUSION: Monorail external fixation over an intramedullary nail is an effective option for post-traumatic femoral defects, reducing external fixator time and returning patients’ quality of life to a level comparable with the normal population.