Congenital pseudarthrosis of the fibula and valgus deformity of the ankle in young children

Treatment of Concomitant Congenital Pseudarthrosis of the Fibula With Propeller Periosteal Flap

INTRODUCTION

Congenital pseudarthrosis of the fibula is not an uncommon condition to accompany congenital pseudarthrosis of the tibia. Persistence of the fibular pseudarthrosis has been linked to inferior outcomes including tibial union and alignment, refractures, and ankle alignment. In this report, we present the results of a pedicled periosteal propeller flap technique for the treatment of fibular pseudarthrosis.

METHODS

Ten children with an average age at surgery of 5.3 years who had congenital pseudarthrosis of both tibia and fibula were studied. The tibia was treated with free vascularized fibular grafting, and the ipsilateral fibula was treated with a technique after resection of the pseudarthrosis. A periosteal flap from the proximal healthy part of the fibula is harvested off the bone, rotated 180° based on a branch from the peroneal vessels to cover the fibular defect and fashioned in the form of a tube filled with bone fragments.

RESULTS

The periosteal flap size ranged from 5 to 7 cm. Follow-up averaged 37.2 months. The tibia was united in all cases; in 2 of them, refractures occurred and healed with conservative management. The fibula was united in 8 cases. At final follow-up, 5 cases showed residual tibial deformity, and 5 showed residual ankle deformity. Average leg-length discrepancy was 1.4 cm (0-3 cm).

CONCLUSION

The pedicled periosteal propeller flap presents a useful new technique for managing concomitant congenital fibular pseudarthrosis.

Refracture, a Potential Complication of the Periosteal Flap Technique Without Bone Graft for Isolated Congenital Pseudarthrosis of the Fibula: A Report of Two Cases and Literature Review

BACKGROUND

It is a rare condition defined by congenital pseudarthrosis of the fibula (CPF), which may be associated with neurofibromatosis (NF) and congenital pseudarthrosis of the tibia. A condition such as this may be symptomatic or asymptomatic, but it requires treatment because of the progression of signs such as ankle valgus and pseudarthrosis of the tibia. There are a number of surgical techniques that can be used to treat this condition, such as tibiofibular fusion, internal fixation, the Ilizarov method, and periosteal flap.

AIM

The goal of this study was to describe the treatment results of two patients with CPF using vascularized fibular periosteal flaps.

CASE REPORT

We described the case of a 5-year-old patient and a 19-month-old patient with isolated CPF. Both patients underwent a distal-based vascularized fibular periosteal flap, and intramedullary fixation was used to treat the patients.

CONCLUSION

The patients had full union in the pseudarthrosis site, but in the end, both had asymptomatic refracture in the union site. Our experiences showed that it is necessary to use strong intramedullary fixation and bone graft.

Congenital Pseudarthrosis of the Fibula: Controlling Ankle Valgus in a Heterogenous Condition

BACKGROUND

Congenital pseudarthrosis of the fibula (CPF) is a rare disorder characterized by a deficiency in the continuity of the fibula and can lead to progressive ankle valgus malalignment. An existing classification system for CPF is imperfect and may contribute to heterogeneity in reporting and discrepancy of outcomes in the literature.

METHODS

Fifteen patients with CPF treated at our institution between 1995 and 2017 were retrospectively identified. Only patients with dysplasia leading to spontaneous fracture or pseudarthrosis were included in this series. The median age at presentation was 2.5 years (range: 3 mo to 13.4 y). The median duration of follow-up from the initial presentation was 11.8 years (range: 2.0 to 24 y). Chart review and serial radiographs were analyzed to assess natural history and outcomes following surgery.

RESULTS

The coexistence of tibial dysplasia in CPF is very common. Patients were classified into 3 groups based on the degree of tibial involvement-group 1: no evidence of tibial dysplasia, group 2: mild tibial dysplasia, and group 3: significant tibial dysplasia. Age at presentation and age at which fibular fracture occurred were progressively younger with a greater degree of tibial involvement (P<0.05). In the absence of surgical intervention, group 1 patients did not undergo progressive ankle valgus (defined as the valgus change in tibiotalar angle by ≥4 degrees), whereas all patients in groups 2 and 3 did (P<0.001). Fibular osteosynthesis was performed in 6 patients, with union seen only in group 1 patients. Ten patients underwent distal tibiofibular fusion, with no cases of nonunion seen. Distal tibiofibular fusion with or without medial distal tibial hemiepiphysiodesis halted the progression of ankle valgus in 8 of the 10 patients. Further progression of ankle valgus occurred only in patients who did not undergo concurrent medial distal tibial hemiepiphysiodesis and with considerable wedging of the distal tibial epiphysis at the time of fusion.

CONCLUSIONS

Tibial dysplasia and CPF are intimately related. Grouping patients on this basis may help guide natural history and treatment and may explain discrepancies in findings in the literature. Fibular osteosynthesis, distal tibiofibular fusion, and medial distal tibial hemiepiphysiodesis may all have an important role in the treatment of CPF.

LEVEL OF EVIDENCE

Level IV-case series.