Minimally invasive cerclage at the tibia using a modified Goetze technique: an anatomical study.

INTRODUCTION: The use of minimally invasive cerclages at the tibia is not very common. First clinical results of a new operative technique published recently showed no increased complication rate. The aim of this anatomical study was to determine, if it is possible to introduce a minimally invasive cerclage at different levels of the tibia without encasing relevant nerves, vessels or tendons into the cerclage using this technique.

HYPOTHESIS: The minimally invasive introduction of a cerclage at the tibia is possible without encasing relevant anatomical structures.

MATERIAL AND METHODS: Using the minimally invasive operative technique in 10 human cadaveric lower legs, cerclages were inserted at 4 different levels of each tibia. They were defined from proximal to distal as level 1-4. The legs were severed at the levels of the cerclages and examined for any relevant encased anatomical structures. Afterwards, the shortest distance between each relevant anatomical structure and the cerclage was measured.

RESULTS: There was no encasing of any relevant anatomical structures in any specimen at any level. In the proximal half of the lower leg, the closest anatomical structures to the inserted cerclage were arteria et vena tibialis posterior (at Level 1: 5,2 resp. 4,3 mm, at Level 2: 4,0 resp. 5,5 mm). In the distal half of the lower leg arteria et vena tibialis anterior (Level 3: 1,8 and 2,0 mm, Level 4: 1,6 and 1,5mm), nervus fibularis profundus (Level 3: 2,2 mm, Level 4: 1,2 mm) and the tendon of musculus tibialis posterior (Level 3: 0,8 mm, Level 4: 1,1 mm) were in closest proximity of the cerclage.

DISCUSSION: The results of this anatomical study suggest, that the minimally invasive insertion of cerclages at the tibia without encasing relevant anatomical structures is possible but requires a correct operative technique. The structures at highest risk are arteria et vena tibialis posterior in the proximal half of the tibia and arteria et vena tibialis anterior, nervus fibularis profundus and the tendon of musculus tibialis posterior in the distal half.

LEVEL OF EVIDENCE: not applicable; experimental anatomical study.