Use of double-row monolateral Trauma-Fix unibar lengthener for femur lengthening in patients with leg length discrepancy

We report the case of a patient in whom the use of monolateral double-row Trauma-Fix lengthener was successful for femur lengthening after initial difficulty in lengthening by using the single-row lengthener.Problem and case reportA girl 12 years of age presented with a leg-length discrepancy (LLD) of 8 cm and left genu valgum deformity due to a trauma-induced left distal femur physial lesion during her infancy. The patient's weight and height were 38 kg and 148 cm, respectively, and the mechanical axis was 16 degrees of valgus at the time of operation. The lengthening procedure was initiated on postoperative day 7 after the initial correction of the genu valgum deformity. However, no distraction was observed at the osteotomy site, and a convergent angulation deformity developed at the pin-clamp joint.Method and outcomeThis problem was resolved successfully with the addition of another row of the Trauma-Fix lengthening device, which was linked via the previously applied pins. A final lengthening of 7.5 cm was achieved in 3 months by using the double-row lengthener without pin tract infection or breakage. The monolateral frame of the Trauma-Fix lengthener was removed in the 11th postoperative month after a solid union of the femur was achieved. The postoperative mechanical axis of the knee was 4 degrees varus. The monolateral double-row lengthener device that showed high efficiency and improved the strength of the ball joints were used along the single-row lengthener, and it may serve as a good alternative for augmentation of insufficient ball joints during limb lengthening.