Case report

Isolated congenital pseudarthrosis of the fibula: A case report

Pseudoartrosis congénita aislada de peroné: un reporte de caso

Sebastián Mosquera-Castillo1,2 Fernando José Dumar-Otero1 Juan David Santander-Landazabal2

1 Universidad Libre - Barranquilla Campus, Faculty of Health Sciences, Orthopedics and Traumatology Program, Barranquilla, Colombia.

2 Universidad Simón Bolívar, Faculty of Health Sciences, Orthopedics and Traumatology Program, Barranquilla, Colombia.

Open access

Received: 07/10/2025

Accepted: 18/06/2026

Correspondence: Fernando José Dumar-Otero. Universidad Libre - Barranquilla Campus, Orthopedics and Traumatology Program, Barranquilla, Colombia. Email: fernandoj-dumaro@unilibre.edu.co.

How to cite: Mosquera-Castillo S, Dumar-Otero FJ, Santander-Landazabal JD. Isolated congenital pseudarthrosis of the fibula: A case report. Rev. colomb. ortop. traumatol. 2026;40:e739. https://doi.org/10.58814/01208845.739

Cómo citar: Mosquera-Castillo S, Dumar-Otero FJ, Santander-Landazabal JD. [Pseudoartrosis congénita aislada de peroné: un reporte de caso]. Rev. colomb. ortop. traumatol. 2026;40:e739. https://doi.org/10.58814/01208845.739

Copyright: ©2026 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, as long as the original author and source are credited.

Abstract

Introduction: Congenital pseudarthrosis of the fibula (CPF) is an uncommon entity, representing less than 1% of all congenital pseudarthroses of the lower limb. It may occur in isolation or in association with congenital pseudarthrosis of the tibia and neurofibromatosis type 1 (NF1). The pathophysiology involves periosteal and vascular alterations that impair osteogenesis, resulting in atrophic nonunion and progressive ankle valgus deformity. Early diagnosis and long-term follow-up are crucial to prevent angular progression and instability.

Case Presentation: A 4-year-old boy presented with progressive valgus deformity of the left ankle, without pain or history of significant trauma. Radiographs demonstrated a hypoplastic fibula with an isolated distal pseudarthrosis and a lateral distal tibial angle (LDTA) of 66°. The patient underwent corrective osteotomy of the fibula, placement of an allogeneic bone graft, and internal fixation with an anatomic locking plate. Immediate postoperative correction achieved an LDTA of 87°. At the 60-month follow-up, the patient remained asymptomatic, with no evidence of refracture or recurrence of the deformity.

Conclusion: Isolated congenital pseudarthrosis of the fibula is an exceptionally rare condition. Surgical correction through stable fixation and bone grafting can achieve long-lasting union and correction of deformity. This case demonstrates that early reconstruction and structured long-term follow-up can result in durable functional and radiographic outcomes.

Keywords: Pseudoarthrosis; Fibula; Ankle Joint; Case Study (MeSH).

Resumen

Introducción: la pseudoartrosis congénita de peroné (PCP) es una entidad infrecuente que representa menos del 1% de todas las pseudoartrosis congénitas del miembro inferior. Puede presentarse de forma aislada o asociada a pseudoartrosis de tibia y neurofibromatosis tipo 1 (NF1). Su fisiopatología se relaciona con alteraciones del periostio y de la vascularización que limitan la osteogénesis, ocasionando una no unión atrófica y una deformidad progresiva en valgo del tobillo. El diagnóstico temprano y el seguimiento prolongado son esenciales para prevenir la progresión angular y la inestabilidad articular.

Presentación del caso: paciente masculino de 4 años con deformidad progresiva en valgo del tobillo izquierdo, sin dolor ni antecedentes traumáticos. Las radiografías evidenciaron un peroné hipoplásico con pseudoartrosis distal aislada y un ángulo tibial distal lateral (LDTA) de 66°. Se realizó osteotomía correctiva del peroné con colocación de aloinjerto óseo y fijación interna con placa bloqueada anatómica. La corrección posoperatoria inmediata alcanzó un LDTA de 87°. En el seguimiento a 60 meses, el paciente permaneció asintomático, sin refracturas, ni recurrencia de la deformidad.

Conclusión: la pseudoartrosis congénita de peroné aislada es una condición excepcionalmente rara. La corrección quirúrgica mediante fijación estable e injerto óseo puede lograr una consolidación duradera y una corrección anatómica sostenida. Este caso demuestra que la reconstrucción temprana acompañada de seguimiento clínico-radiográfico estructurado permite resultados funcionales y radiológicos favorables a largo plazo.

Palabras clave: Seudoartrosis; Peroné; Articulación del Tobillo; Presentación de Caso (DeCS).

Introduction

Congenital Pseudarthrosis of the Fibula (CPF) is a rare condition that may present in isolation or in association with congenital pseudarthrosis of the tibia and neurofibromatosis type 1 (NF1).1-4 It has also been linked to skeletal abnormalities of the lower limb, including anterolateral bowing of the tibia, a deformity classically associated with congenital developmental disorders.1,4,5 Its pathophysiology involves alterations of the periosteum and local vascularization that limit osteogenesis, leading to atrophic nonunion and progressive angular deformity.4,5

The characteristic clinical sign of CPF is ankle valgus deviation, resulting from loss of distal lateral fibular support and tilting of the talar dome.5 Radiographically, fibular discontinuity is evident, with atrophic or sclerotic ends and, in some cases, bone shortening.6,7 Treatment of CPF aims to restore bone continuity and distal axis alignment while maintaining ankle stability. Various contemporary strategies are currently used for its treatment, including autologous grafts, vascularized periosteal flaps, corrective osteotomies, and tibiofibular synostosis.3,5,8,9 Given this, long-term follow-up is essential to detect angular recurrence or late refracture.1,9-11

The following is the case of a boy diagnosed with isolated CPF, treated by means of corrective osteotomy, fixation with an anatomic locking plate, and allograft use, with favorable clinical outcomes observed over a 5-year long-term follow-up.

Case Presentation

A 4-year-old male patient was brought to the Orthopedics and Traumatology department of a tertiary care hospital in Barranquilla, Colombia, for progressive valgus deformity of the left ankle. The parents reported a history of torsional ankle trauma approximately three years prior to the consultation, for which the patient received no medical evaluation or subsequent immobilization.

At the time of consultation, the patient reported no pain, and no significant functional limitation was observed. Physical examination identified valgus deformity of the left hindfoot, a normal gait without limping and preserved ankle stability, with no signs of inflammation or tenderness to palpation. No cutaneous stigmata or family history compatible with NF1 were found.

Subsequently, one week after the initial consultation, radiographs of the left leg (anteroposterior and lateral views) were obtained, showing a hypoplastic fibula with a pseudarthrosis focus in the distal third, without tibial pseudarthrosis or diffuse bone dysplasia (Figure 1). The initial lateral distal tibial angle (LDTA) was 66°, indicating severe valgus angular deformity. Based on these findings, the patient was diagnosed with isolated CPF associated with ankle valgus, and surgical management was indicated.

Figure 1. Radiograph of the left leg. A. Lateral view. B. Anteroposterior view.

Source: Images obtained during patient management.

Surgical intervention

The therapeutic goal was to restore fibular continuity, correct the angular axis, and stabilize the tibiotalar joint. Under general anesthesia and fluoroscopic guidance, osteotomy of the left fibula was performed with resection of the pseudarthrosis focus and three-dimensional correction of the deformity. A structural bone allograft was placed at the osteotomy site, along with internal fixation using an anatomic locking fibular plate. Restoration of distal alignment and of the ankle joint axis was adequate (Figure 2).

Figure 2. Postoperative radiograph of the left ankle. A. Anteroposterior view. B. Lateral view.

Source: Images obtained during patient management.

At the end of surgery, satisfactory correction of the valgus deformity was confirmed, with an intraoperative LDTA of 87°. The limb was immobilized with a posterior suro-pedal splint, partial weight-bearing was indicated at 15 days, and according to the patient’s tolerance and clinical progress, weight-bearing was advanced to full.

Follow-up and clinical outcomes

Clinical and radiographic follow-up was performed periodically at 6 weeks, 3 months, 6 months, and 12 months, and then annually up to 60 months (5 years) after surgical management. At 6 weeks, the patient showed adequate clinical progress, with no surgical wound complications, signs of infection, or loss of the correction achieved. Radiographs showed adequate positioning of the osteosynthesis hardware and maintenance of ankle alignment. At 3 and 6 months, radiographic progression and changes were observed, with no signs of implant loosening, loss of correction, or recurrence of the deformity. Clinically, the patient remained pain-free with adequate tolerance to walking.

At one year, radiographs showed complete consolidation at the osteotomy site, with restoration of the anatomic axis and physiological ankle alignment. A gait without limping and the absence of pain or functional limitations were also reported. Hardware removal was performed one year after surgery, without complications (Figure 3).

Figure 3. Postoperative radiograph of the left ankle. A. Anteroposterior view. B. Lateral view.

Source: Images obtained during patient management.

Subsequent follow-up visits showed no adverse events, loss of correction, deformity recurrence or signs of refracture. At the 60-month follow-up after the procedure, the patient presented a symmetric, physiological gait with adequate hindfoot alignment and preserved varus and valgus stability of the ankle, with no syndesmotic injury or leg length discrepancy (Figure 4). Furthermore, no signs of deformity recurrence or fibular refracture were observed on the follow-up radiograph.

Figure 4. Clinical follow-up images 60 months after the surgical procedure.

Source: Images obtained during patient management.

Discussion

In most reported cases, fibular involvement is associated with tibial pseudarthrosis or NF1, whereas truly isolated cases, such as the one presented here, are extremely uncommon.6 Dooley et al.2 were the first to describe this rare presentation and highlighted its association with angular ankle deformities, particularly valgus. In later studies, Dal Monte et al.3 and Lampasi et al.5 observed that, even with surgical treatment, the risk of angular ankle progression and refracture during growth persisted, particularly when stable anatomic correction was not achieved.

In this case, as evidenced by the 60-month postoperative follow-up, osteotomy with rigid fixation (anatomic locking plate) and allograft placement allowed complete bone consolidation as well as durable correction of the joint axis, with no recurrence of deformity or refracture. This follow-up duration exceeds the average observation period reported in the literature reviewed, where monitoring generally does not extend beyond three years.4,5,8

Ankle mechanical stability was decisive in achieving this outcome, consistent with the findings of Wang et al.,1 who emphasize the importance of restoring distal lateral ankle support to prevent progressive valgus. In contrast, Zargarbashi et al.10 reported early fractures in patients treated with periosteal flaps alone, without bone grafting, reinforcing the need for solid structural reconstruction and adequate biological stimulus.

Thus, the prolonged follow-up without evidence of progressive deformity, laxity, or length discrepancy in this patient suggests that early fibular reconstruction, combined with continuous monitoring, may contribute to maintaining ankle alignment and stability throughout growth. This finding is consistent with the work of Wang et al.,1 who emphasize the importance of preserving ankle biomechanics and performing longitudinal follow-up to detect progressive alignment changes. While El-Gammal et al.11 proposed the use of vascularized periosteal flaps in complex cases, the results of this case may demonstrate that a simpler technique can be equally effective when the principles of rigid stability and complete correction are met.

Overall, this report provides valuable clinical evidence by documenting a stable, complication-free course over five years. This underscores the importance of precise anatomic surgical management and prolonged follow-up, particularly in a disease whose low frequency limits the development of evidence-based treatment guidelines.

Limitations

This report presents certain limitations inherent to its single-case design and retrospective nature. Not all clinical, imaging, and complementary data that could have enriched the diagnostic characterization and comprehensive analysis of the case were available. Likewise, although a favorable clinical and radiographic course was documented during follow-up, the absence of certain complementary evaluations limits the interpretation of some findings. Finally, despite the prolonged follow-up, the patient has not yet reached skeletal maturity, so continued long-term follow-up remains necessary to assess the definitive outcome and detect possible late complications.

Conclusion

Isolated CPF is a rare condition, and few references exist to guide its treatment. The course observed in this case supports early fibular reconstruction as a valid alternative for restoring ankle stability and achieving limb alignment. Long-term follow-up remains an essential component of its management.

Informed consent

The patient’s parents signed an informed consent authorizing the use of their clinical data for the preparation and publication of this case report.

Conflicts of interest

None reported by the authors.

Funding

None declared by the authors.

Acknowledgements

None reported by the authors.

Use of artificial intelligence

None reported by the authors.

References

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