The Ilizarov bone transport technique has been proven to be an effective method for treating tibial bone defects caused by fracture-related infections [1, 3, 11]. The combined technique of EFOIN proposed in previous studies allows for effective control of the alignment of the transported bone segment via an intramedullary nail, thus avoiding axial deviation [12]. Furthermore, this technique can greatly shorten the EFT and EFI by removing the external fixator after the distraction phase, and further reduce the occurrence of external-fixation-related complications [9]. In this cohort, all 25 patients (100%) were successfully treated with bone transport using EFOIN, with a minor complication rate of 0.76. Therefore, bone transport using a combined technique of EFOIN offers significant advantages in restoring lower limb alignment and reducing postoperative complications.
The Ilizarov bone transport technique using a circular external fixator has some limitations, such as long treatment time, cumbersome appearance, and high incidence of postoperative complications [5]. Although the application of unilateral external fixators improves the appearance of external fixators and patient compliance, this technique still faces high EFT and EFI. In recent years, orthopedic researchers have proposed bone transport using EFOIN, which significantly reduces EFT and EFI, including external fixator combined with intramedullary nails [9], and plate-assisted bone segment transport [13]. Guo et al. [14] reported a comparative study of tibial lengthening over an intramedullary nail versus the conventional Ilizarov method and suggested that tibial lengthening over an intramedullary nail conferred advantages in reducing EFT with a lower complication rate. Farsetti et al. [15] presented 28 patients with lower limb discrepancy treated by limb lengthening over an intramedullary nail and considered that this method can reduce EFT, prevent the occurrence of axial deformities, and fractures of regenerated bone. In this study, bone transport using EFOIN was shown to have certain advantages in promoting bone union (100%) and reducing EFT and EFI. However, intraoperative blood loss and operation time in Group B were higher than those of Group A (P < 0.05). We believe this may be due to the simpler surgical procedures of unilateral external fixators. Besides, the application of minimally invasive osteotomy is also important for bone transport surgery in reducing intraoperative blood loss.
Intramedullary nailing is considered the gold standard for managing long bone fractures in the lower limbs, providing satisfactory axial stability, stiffness, and minimal soft tissue injury [16]. In bone transport, the addition of intramedullary nailing can keep the distracted bone segment stable and minimize EFT and loss of axial alignment. However, some scholars have reported that bending deformities of the distraction area may occur at the proximal tibial osteotomy site when treating distal tibial bone defects using EFOIN [13, 17, 18]. Hence, a plate-assisted bone transport technique was developed. Oh et al. [13] presented a total of 10 patients with infected post-traumatic segmental tibial defects effectively managed by distraction osteogenesis with a locking plate. Lu et al. [19] reported a series of 12 patients with segmental tibial defects successfully treated by a combined bone transport technique of circular external fixation and locking plate application. In our experience, the application of intramedullary nailing can guide the distracted bone segment and provide axial stability during bone transport, preventing the occurrence of axial deviation and bending deformity of the distraction area. The inserted screws of assisted locking plate may harm the periosteal blood supply and leave a high incidence of stress shielding, which may result in pathological bone resorption of the distraction area. Besides, reaming during the use of intramedullary nails can also act as an internal bone grafting to promote bone regeneration in the distraction area. Therefore, although bone transport using a plate may reduce the risk of bending deformities in the distraction area, intramedullary nailing can be a better choice.
Previous studies have reported pin tract infection as the most common complication in external fixation treatment. Additionally, there is a high risk of axial deviation and transport gap bending deformity with bone transport using a unilateral external fixator [3, 11]. In this study, the most common complications were pin tract infections (Group A vs Group B, 3 cases vs 6 cases), followed by radiating foot pain (Group A vs Group B, 2 cases vs 5 cases). However, neither axial deviation nor transport gap bending deformity was observed. The complication ratio (per patient) in Group A was lower than that of Group B (P < 0.05). We consider that more screws or pins are present when using a circular fixator, which increases the risk of pin tract infection. The distraction procedure during the distraction phase of circular external fixation is more complex than that of unilateral external fixation, which may leave a higher risk of irritating peripheral nerves during insertion and further lead to radiating foot pain. This further complicates rehabilitation for patients, as they may experience difficulty performing exercises to improve mobility in adjacent joints, leading to joint stiffness. Therefore, bone transport with a unilateral external fixator over an intramedullary nail can result in lower complication rates and better functional results.
Despite the satisfactory outcomes observed, there is a significant risk of infection spreading to the medullary canal when using intramedullary nails [20]. Although all cases in this study successfully eradicated the infection without recurrence, infected lesions often present difficulties due to previous surgeries, poor soft tissue coverage and circulation. As such, it is crucial to utilize sensitive systemic antibiotics, perform radical debridement, and implement meticulous postoperative management. Additionally, patients should be carefully instructed on pin tract care to prevent pin tract loosening or the spread of infection.
This study had several limitations. Firstly, the absence of a standardized algorithm for managing tibial bone defects caused by infection may have affected the correlation between various treatment methods. Furthermore, interpretations of bone and functional outcomes should be approached with caution, due to the retrospective nature and small sample size of this study. Therefore, it is crucial to conduct a large-scale, multi-center, and prospective study to accurately evaluate the clinical efficacy of bone transport using EFOIN.