Limb lengthening and then insertion of an intramedullary nail: a case-matched comparison

Abstract

Distraction osteogenesis is an effective method for lengthening, deformity correction, and treatment of nonunions and bone defects. The classic method uses an external fixator for both distraction and consolidation leading to lengthy times in frames and there is a risk of refracture after frame removal. We suggest a new technique: lengthening and then nailing (LATN) technique in which the frame is used for gradual distraction and then a reamed intramedullary nail inserted to support the bone during the consolidation phase, allowing early removal of the external fixator. We performed a retrospective case-matched comparison of patients lengthened with LATN (39 limbs in 27 patients) technique versus the classic (34 limbs in 27 patients). The LATN group wore the external fixator for less time than the classic group (12 versus 29 weeks). The LATN group had a lower external fixation index (0.5 versus 1.9) and a lower bone healing index (0.8 versus 1.9) than the classic group. LATN confers advantages over the classic method including shorter times needed in external fixation, quicker bone healing, and protection against refracture. There are also advantages over the lengthening over a nail and internal lengthening nail techniques.

Level of evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Fig. 1A–D

This is a sawbone model illustrating LATN technique. (A) An axial view shows proximal fixation placed peripherally to avoid contact with future intramedullary nail. (B) This is a front view after 4-cm lengthening; note absent fixation on the middle ring. (C) Insertion of intramedullary nail is shown; note the targeting jig (EBI, Biomet Trauma, Parsippany, NJ) is not blocked by frame. (D) A Front axial view shows the proximal pin configuration and that the intramedullary nail is not blocked by the external fixation.

Fig. 2A–I

This is an example of a 23-year-old woman who underwent correction of varus, recurvatum, external rotation malunion, and 2.5 cm lengthening. (A) A preoperative front view shows deformity and shortening. (B) This is a preoperative AP radiograph. (C) This is a preoperative lateral radiograph. (D) This is an erect leg radiograph at end of distraction showing equal leg lengths and correction of deformity. (E) This is an AP radiograph 2 weeks after insertion of intramedullary nail. (F) This is an AP radiograph 3 months after insertion of intramedullary nail. (G) This is a lateral radiograph 3 months after insertion of intramedullary nail. (H) This is a front view 2 years after surgery. (I) This is an AP radiograph 2 years after surgery.

Fig. 3A–C

This is an example of a 45-year-old man who underwent 5 cm lengthening. (A) This is an anteroposterior (AP) radiograph at the end of distraction. (B) This is an AP radiograph 8 weeks after insertion of the intramedullary nail. (C) This is a lateral radiograph 8 weeks after insertion of the intramedullary nail.

Fig. 4A–E

This is an example of a 55-year-old woman who underwent ankle fusion and 10 cm lengthening for a segmental bone defect. (A) This is an AP radiograph at end of 10 cm distraction; the ankle fusion is stabilized more distally. (B) This is an AP radiograph 4 months after insertion of the intramedullary nail. (C) This is a lateral radiograph 4 months after insertion of the intramedullary nail. (D) This is an AP radiograph 9 months after insertion of the intramedullary nail. (E) This is a lateral radiograph 9 months after insertion of the intramedullary nail.