Secondary nailing after external fixation for tibial shaft fracture: Risk factors for union and infection. A 55 case series

Abstract

Introduction: Secondary intramedullary nailing (SIN) following external fixation (EF) of tibial shaft fracture is controversial, notably due to the infection risk, which is not precisely known. The present study therefore analysed a continuous series of tibial shaft SIN, to determine (1) infection and union rates, and (2) whether 1-stage SIN associated to EF ablation increased the risk of infection. Hypothesis: Factors exist for union and onset of infection following tibial shaft SIN. Materials and methods: A retrospective series of SIN performed between 1998 and 2012 in over 16-year-old patients with non-pathologic tibial shaft fracture was analysed. EF pin site infection was an exclusion criterion. Fractures were graded according to AO and Gustilo classifications. Study parameters were: time to SIN, 1- versus 2-stage procedure, bacteriologic results on reaming product, post-nailing onset of infection, and time to union. Results: Fifty-five patients (55 fractures) were included. There were 16 closed and 39 open fractures: 7 Gustilo type I, 26 type II and 6 type IIIA; 33 AO type A, 14 type B and 8 type C. Mean time to SIN was 9 ± 9.6 weeks (range, 4 days to 12 months). There were 23 1-stage procedures, and 32 two-stage procedures with a mean 12-day interval (range, 4-30 days). Twelve reaming samples were biologically positive without secondary infection. There were 4 septic complications (3 abscesses, 1 osteomyelitis), and 1 aseptic non-union required re-nailing. The union rate was 96%. The sole factor of poor prognosis was severity of fracture opening. One-stage SIN did not increase infection risk. Discussion: The present results were better than reported in the literature, where the rates of Gustilo IIIA and IIIB fracture and pin site infection are, however, higher. Tibial shaft SIN is a reliable procedure, with infection risk correlating with Gustilo type and time to surgery. Surgery should be early, before onset of EF pin site infection. A 1-stage attitude appears feasible in early SIN. Level of evidence: Level IV. Retrospective study type.