Tibialization in a Pediatric Patient Following Postinfectious Tibial Bone Loss

Summary:

We present the case of a 4-year-old boy with a right leg deformity secondary to extensive postinfectious tibial bone loss. The patient underwent multiple incisions and drainage procedures and a sequestrectomy, resulting in a significant tibial defect. Definitive management was achieved through tibialization of the ipsilateral fibula. Tibialization was performed at the age of 4 years with a total of 2 years of follow-up. This case highlights the surgical principles, functional outcomes, and unique considerations of tibialization in the pediatric population.

Pyomyositis is a bacterial infection of the muscle, and it is not secondary to contiguous infection of the skin, bone, or soft tissue.¹ Osteomyelitis is an inflammatory bone condition caused by microbial infection. It is accompanied by the destruction of the bone tissue.²

Defects greater than 8 cm are accepted as massive or mega bone defects.³ In cases of large bone defects, the bone loses its ability to repair itself without external intervention. This may lead to delayed bone union, nonunion, and a high rate of patient disability.⁴

Tibialization of the fibula was first described by Albert in 1877 and pioneered by Hanh and Huntington. Albert obtained a fusion between the fibula and femur in a patient with a congenital absence of the proximal tibia. The procedure has been used successfully in many limb-salvaging operations.⁵

CASE PRESENTATION

Patient Information

A 4-year-old boy presented with a 3-year history of right leg deformity following pyomyositis at 15 months of age in the setting of severe acute malnutrition. He previously underwent multiple incision and drainage procedures and tibial sequestrectomy for chronic osteomyelitis, resulting in a significant bone defect.

Examination revealed right leg shortening with bowing and ankle angulation, and a palpable distal tibial gap as shown in Figure 1. An x-ray image showed right tibial bone gap with sclerosis and tapering of distal segment of tibia, as shown in Figure 2. The ankle had preserved flexion and internal rotation with limited external rotation. Imaging demonstrated a long-segment distal tibial defect with cortical irregularity, osteolysis, and periosteal reaction, with associated ankle joint destruction on computed tomography. Laboratory findings were unremarkable.

Fig. 1.

The right leg showing significant shortening and angular deformity preoperatively.

Fig. 2.

Preoperative anteroposterior view x-ray of the right leg showing a tibial bone gap with sclerosis and tapering of the distal segment of the tibia.

Surgical Technique: Tibialization of the Fibula

Preoperative assessment included computed tomography angiography to ensure the vascular integrity of the fibula. Several reconstructive options were considered, including free vascularized bone transfer and Ilizarov bone transport. However, given the resource-intensive nature of microsurgery and the lack of specialized Ilizarov equipment in our setting, the decision was made to perform an ipsilateral fibular transposition.

During the procedure, the fibula was found to be naturally hypertrophied—a common physiological response to the tibia’s inability to bear weight. The tibia was atrophied in its distal third with a total bone gap of 12 cm. The fibula was approached via an anterior incision, mobilized on its vascular pedicle, and osteotomized to fit the defect. We used an “end-to-end” telescoping technique, securing the fibula into the proximal and distal tibial remnants. For stabilization, a rush rod was inserted through the calcaneus and up through the transposed fibula, as shown in Figure 3. Although Ilizarov fixation is often preferred for its stability, the rush rod provided a cost-effective and feasible stabilization method within our clinical constraints. The limb was initially immobilized in a posterior gutter for 2 weeks to allow for soft tissue healing. This was followed by a circular cast for 4 weeks. Weight-bearing was strictly prohibited for the first 6 weeks, after which gradual loading was introduced under clinical supervision.

Fig. 3.

Intraoperative picture of the fibula being transposed on its vascular pedicle and telescoped medially into the tibia defect, secured with a rush rod inserted through the calcaneus.

Outcome and Follow-up

The patient’s recovery was excellent. Serial radiographs at 6 weeks postoperatively confirmed successful bony union at both the proximal and distal junctions. Over the next 2 years, the transposed fibula showed marked signs of hypertrophy, increasing in diameter to support the patient’s increasing weight as shown in Figure 4.

Fig. 4.

Postoperative lateral x-ray of the right leg showing hypertrophied and unified tibia.

At the most recent follow-up, the patient was independently ambulatory and could bear full weight on the affected limb without assistive devices. Although a 5-cm limb-length discrepancy remains, causing a visible limp, the patient maintains a functional range of motion in the knee and subtalar joints as shown in the Video. (See Video [online], which displays 2 years postoperative assessment demonstrating independent ambulation.) He is currently attending school and participating in routine play activities with his peers.

Video 1. Two years post operative assessment demonstrating independent ambulation.

Download video file ^{(8.3MB, mp4)}

DISCUSSION

Large bone defects are tissue deficits that cannot heal spontaneously, requiring surgical reconstruction to restore function and prevent amputation. Amputation necessitates the use of a prosthesis. Prostheses in Ethiopia, however, are not covered by insurance and are bought out of pocket.⁶ High-tech prostheses are quite expensive and need to be imported, which makes the price even higher.⁷ Management approaches are broadly categorized into repair and reconstructive techniques. Repair methods, such as distraction osteogenesis, pioneered by Ilizarov, and reconstructive methods restore bone continuity by replacing the defect with autologous or allogenic bone, often using vascularized grafts or the Masquelet technique to achieve structural and functional recovery.^8,9

Tibialization is a well-established method for treating segmental tibial defects, especially where microvascular reconstruction is limited. In children, the vascularized fibula gradually hypertrophies to assume the tibia’s load-bearing role. Successful outcomes depend on preserved fibular vascularity, stable fixation, and progressive rehabilitation. Hypertrophy—often doubling the original diameter or matching the contralateral tibia—is common after fibula centralization and is most pronounced in younger patients, correlating with solid bony union and early weight-bearing.¹⁰

This case underscores the value of tibialization in resource-limited environments, offering a durable, biological reconstruction for extensive tibial bone loss in children.

CONCLUSIONS

Tibialization of the fibula offers a reliable, cost-effective solution for large tibial defects in pediatric patients, especially in postinfectious cases. With meticulous technique and long-term follow-up, satisfactory functional and structural outcomes can be achieved.

RECOMMENDATION

A limb-length discrepancy was noted in this patient, and limb-lengthening procedures are planned. According to a Hospital for Special Surgery article, limb lengthening is commonly performed at 8 years of age.¹¹ In the interim, the patient is managed with orthotic support, including shoe inserts, to enhance stability and facilitate functional ambulation.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.