Promises and difficulties with the use of femoral intra-medullary lengthening nails to treat limb length discrepancies.

Limb lengthening using external fixation may be associated with problems such as pin-track infections, poor patient acceptance, muscle transfixation, secondary axial deformity and re-fractures. Intramedullary lengthening nails have been designed to address these issues. We present our results for femoral limb lengthening in adults managed by intramedullary lengthening nails. A retrospective review was undertaken for 8 femoral lengthening procedures performed in adults using intra-medullary lengthening nails over a three-year period. The average age of our patients was 34 years; the average duration of follow-up was 26.5 months (range: 8 to 40 months). An Albizzia nail was used in 5 procedures, an Intra-medullary Skeletal Kinetic Distractor (ISKD nail) in 3 procedures. Target lengthening was achieved in 6 out of 8 femurs with an average of 38.77 mm (range: 0 to 70 mm) length gained. The distraction index (length gained per day) was 0.58 on average (range: 0-1.25) and the consolidation index average was 5039 (range: 0-79) days/cm. Premature consolidation was noted in 4 cases, runaway acute lengthening in one patient; prominent metalwork--noted in 4 patients--and a bent nail were frequent obstacles and meant multiple visits to theatre. Femoral lengthening with an intramedullary lengthening nail is a reasonable alternative to external fixators, thereby avoiding problems associated with callotasis using external fixation methods. It is however, important to counsel patients regarding possibilities of significant obstacles including failure and multiple visits to theatre during the process.