Gradual Transverse Transport of Naturally Tibialized Fibula Using Hexapod Frames to Treat Neglected Type V Tibial...

Although several reconstructive methods have been developed to manage large segmental tibial bone defects including bone transport (distraction osteogenesis), contralateral fibular graft, allograft, tibiofibular synostosis, Masquelet technique, and 3D printed scaffold, neglected large tibial defects in adults remain challenging problems. This study describes gradual transverse transport of naturally tibialized fibula using hexapod frames in management of adult patients with neglected large tibial defects.

We retrospectively reviewed four cases of transverse transport of naturally tibialized fibula from November 2018 to February 2022. We measured the length of the tibial defect and the transported fibular segment, the mid-diaphyseal diameter and cortical thickness of the affected fibula, contralateral fibula, and tibia. The parameters measured both preoperatively and postoperatively were leg length discrepancy, hip-knee-ankle angle, medial proximal tibial angle, posterior proximal tibial angle, lateral distal tibial angle, range of motion of the knee and ankle joints, and Lower Extremity Functional Scores (LEFS). Patients' satisfaction rates using Likert scale were also recorded.

Among four female patients, three suffered from tibial osteomyelitis, and one was due to congenital pseudarthrosis of the tibia. The average follow-up time was 2.7 ± 1.4 years. The average length of tibial defect was 14.0 ± 0.8 cm. The average preoperative shortening of the affected leg was 9.0 ± 2.5 cm, which changed to 0.6 ± 0.8 cm postoperatively. The median length of the transported fibular segment was 15.2 cm. Two patients had varus deformity, two had recurvatum, and one had procurvatum preoperatively. Postoperative radiological measurement showed all deformities corrected and no ankle valgus deformity developed during follow-up. All patients achieved union and can fully weight bear on the affected extremity. The average fixator time was 12.9 ± 2.9 months. The average preoperative and postoperative LEFS, respectively, were 53.5 ± 5.0, 70.5 ± 1.3, with a significant difference (p = 0.003). Three patients reported very satisfied with the outcome, and one patient reported satisfied. Three patients had pin tract infections, and one patient had skin necrosis which healed after additional surgery. One patient had surgical release of the hamstring tendons due to flexion contracture of the knee. Two patients had 15° of reduction in ankle range of motion. One patient had transient common peroneal nerve palsy which spontaneously recovered within 6 weeks.

The transverse transport of naturally tibialized fibula was both a safe and effective method to treat the long-standing type V tibial segmental defect.