Lengthening Over an Existing Intramedullary Nail In Cases of Post-traumatic Femoral Shortening. Technical Note. Case Series Study

Distraction osteogenesis in combined sequential use of external fixation and nailing (lengthening and then nailing): An experimental study in rabbits

Limb lengthening relies on the process of distraction osteogenesis. The active periosteal bone formation has been detected in clinical practice with a lengthening and then nail (LATN) technique but has not been confirmed by experimental studies to date. The aim of this study is to compare the tissue regeneration of the distraction regenerate during tibial lengthening in rabbits using a LATN technique. This study was performed on 54 mature rabbits of the Soviet Chinchilla breed, which were divided into three groups of 18 animals. In group 1 (control), the tibia was lengthened in an external fixator. In group 2, the LATN technique was modeled and in group 3, lengthening over nail (LON) was modeled. The total duration of the experiment was 45 days. On the 10th, 15th, 20th, 30th, and 45th day X-ray, computed tomography and morphological studies were performed. In the experimental groups (2 and 3), a more pronounced periosteal bone formation in the area of regenerate was noted when compared to group 1. In group 2 (LATN), wide cortical plates were formed from the intermediate and periosteal areas. In this group, the maximum densitometric density values were noted. Endosteal bone formation was preserved in all groups. The LON and LATN techniques, when compared with the classical Ilizarov lengthening, do not demonstrate any deficiency in the tissue regeneration of the bone tissue at the regenerate sites. The most powerful bone structures are formed with the sequential use of the external fixation and nailing (LATN).

Bifocal Bone Transport over a Preexisting Nail to Treat a Septic Femoral Shaft Nonunion

Intramedullary nailing is the method of choice for the treatment of most femoral shaft fractures. However, it is not always an easy procedure with predictable results as leg length discrepancy as well as rotational and angular malunion may occur. Lengthening over an intramedullary nail (IMN) has become very common as it allows early removal of the external fixator. This report presents a case of an open femoral shaft fracture initially treated with an IMN and subsequently complicated by a septic nonunion. Union was obtained by bifocal bone transport with a circular external fixator over the preexisting nail without exchange or removal of the previously inserted IMN. In conclusion, the presence of an IMN supports osteotomy and regenerates bone during bone healing, prevents fracture and/or deformation of the regenerated bone, and reduces the time needed for the external fixator.