Angiographic evaluation of arterial configuration after acute tibial shortening.

INTRODUCTION

Tibial nonunion with bone and soft tissue loss is a challenging orthopedic problem. Acute tibial shortening is a well-defined technique; however, arterial configuration following acute tibial shortening has not been demonstrated by a clinical study.

MATERIALS AND METHODS

Sixteen patients with tibial nonunion and one patient with acute tibial fracture accompanied by bone and soft tissue loss were treated by acute shortening followed by compression or relengthening between 2004 and 2010. Circulation was monitored by intraoperative Doppler ultrasound and hallux pulse oximetry. Arterial configuration was examined by digital subtraction angiography at the seventh postoperative day and by CT angiography at the second year. Bone healing and functional results were evaluated according to Paley's classification, and complications were evaluated according to Dahl's classification.

RESULTS

Mean amount of bone loss was 3 ± 1.4 cm (range 1-6 cm); mean size of the soft tissue defects was 7 × 6.8 cm (range 3 × 3 cm-10 × 10 cm). The mean follow-up period was 38 ± 11.3 months (range 24-57 months). The average amount of acute shortening was 5.4 ± 1.6 cm (range 3-8 cm). Average lengthening was 6 ± 1.8 cm (range 4-8 cm), and the mean external fixation index was 1.4 months/cm (range 0.1-3.7 months). There was no detectable change in the arterial configuration of patients with acute shortening up to 4 cm. Minimal arterial bending was observed in patients that 4-6 cm of shortening was performed. Arterial configuration of the patients that 8 cm acute shortening was performed showed increased tortuosity, but the patency was maintained.

CONCLUSION

Acute shortening of tibia in nonunions with soft tissue defects allows for primary closure or reduces the need for grafting and secondary operations. Although the amount of acute shortening depends upon intraoperative assessment with Doppler ultrasound and hallux pulse oximetry, acute compression up to 8 cm can be attained in proximal tibia. More than 4 cm of acute shortening leads to increased tortuosity of major arteries rather than kinking, and this new arterial configuration is maintained for up to 2 years with no problem in circulation.