Jong Keon Oh

Hybrid external fixation of distal tibial fractures: new strategy to place pins and wires without penetrating the anterior compartment

IntroductionImpalement of the anterior compartment musculature remains a problem in the hybrid external fixation of distal tibial fractures. The purposes of this study were to develop a tensioned wire configuration which does not violate the anterior compartment and to analyze the biomechanical implications of new wire configuration.Materials and methodsThirty-seven adult volunteers without known pathology around either tibia were recruited. Axial computed tomography of the distal tibia was performed at 5-mm slices from the plafond to the upper margin of the syndesmosis. The wire convergence angle was measured at the 1-, 2-, and 2.5-cm levels using the following landmarks: tibialis anterior tendon (TA), tibialis posterior tendon (TP), peroneus brevis tendon (PB), anterolateral border of the lateral malleolus (LM). Two straight lines were drawn by connecting TA and PB and connecting TP and LM. The wire convergence angle was defined as an acute angle between these two lines. Then the orientation of the bisector axis of the wires was measured. As a second part of this study, a validated three-dimensional hybrid external fixator model was developed using finite elements modeling to analyze the stiffness of the frames constructed according to the measured wire convergence angle and orientation. Five simulated configurations were tested. The stiffness of each frame was analyzed under four load conditions: torsion, axial compression, side bending, and anteroposterior bending.ResultsThe mean convergence angle was 30° irrespective of the level. The bisector axis was oriented towards the anterolateral direction about 20° from the coronal plane. The stiffness of the frame constructed with a wire convergence angle of 30° and an anterolateral wire orientation of 20° was 20–30% less than that of the frame constructed with 60° wires oriented in a coronal plane. The addition of an anteromedial half-pin increased the stiffness significantly.ConclusionsTwo tensioned wires may be placed without violating the anterior compartment by using the above four clinically identifiable landmarks. Addition of a half-pin on the anteromedial surface of the distal articular fragment makes the frame markedly stiffer than is possible using the standard wire configuration.

Treatment of open tibial shaft fractures using tightly fitted interlocking nailing

Between 2000 and 2003 we treated 23 patients who sustained open tibial shaft fractures with tightly fitted interlocking intramedullary nailing. There were three grade I, eight grade II, nine grade IIIa, and three grade IIIb open fractures. Nail diameters were decided on using preoperative and intraoperative radiographs. Nails were introduced after gentle passage with a 7- to 8-mm hand reamer. Union was obtained in all cases. Nine (37.5%) fractures, however, required additional procedures before union. Three of them gained union through exchange nailing, bone graft, and bone transport, respectively. The remaining six underwent dynamisation. Two of them required an additional exchange nailing for non-union; thereafter one healed and the other gained union through an additional bone graft. Deep infection occurred in one case. Screw breakage occurred in one case only. Tightly fitted nailing produced a significantly lower incidence of locking screw breakage. However, even with this advantage, this technical modification has failed to show clinical advantage in terms of higher healing rate or lower rate of secondary procedures.RésuméEntre 2000 et 2003, nous avons traité 23 patients qui présentaient une fracture ouverte de la diaphyse tibiale par clou verrouillé intra médullaire. Il s’agissait de 3 Grades I, de 8 Grades II et de 9 Grades IIIa ainsi que 3 Grades IIIb. Le diamètre du clou a été décidé d’après les radiographies préopératoires, durant l’intervention et en fonction des résultats de la radiographie per-opératoire. Les clous ont été introduits après un passage d’alésoires de 7 à 8 mm. La consolidation a été obtenue dans tous les cas. 9 fractures (37,5%) ont nécessité une procédure additionnelle pour obtenir la consolidation, 3 ont pu être consolidées après le changement de clou avec une greffe ou un transport osseux. Les six patients restant ont nécessité une dynamisation du montage. Deux d’entre-eux ont nécessité un changement de clou pour pseudarthrose. Les deux ont consolidé grâce à une greffe. Nous avons observé une infection profonde dans un cas, des fractures de vis dans un cas. Cette attitude thérapeutique nous semble tout à fait justifiée et présente des avantages pour obtenir une consolidation assez rapide ou tout au moins une consolidation retardée, secondaire assez précoce.