Salvage of congenital pseudarthrosis of the tibia by the induced membrane technique followed by a motorised lengthening nail

Anterolateral Tibial Bowing and Congenital Pseudoarthrosis of the Tibia: Current Concept Review and Future Directions

PURPOSE OF REVIEW

Congenital pseudarthrosis of the tibia (CPT) is a rare condition closely associated with neurofibromatosis type I. Affected children are born with anterolateral bowing of the tibia which progresses to pathologic fracture, pseudarthrosis, and high risk of refracture even after initial union has been attained. There is currently no consensus on the classification of this disease or consensus on its treatment. The purpose of this review is to (1) review the clinical presentation, etiology, epidemiology, classification, and natural history of congenital pseudarthrosis of the tibia and (2) review the existing trends in treatment of congenital pseudarthrosis of the tibia and its associated complications.

RECENT FINDINGS

Current treatment protocols focus primarily on combining intramedullary fixation with external or internal fixation to achieve union rates between 74 and 100%. Intramedullary devices should be retained as long as possible to prevent refracture. Cross-union techniques, though technically difficult, have a reported union rate of 100% and no refractures at mid- to long-term follow-up. Vascularized fibular grafting and induced membrane technique can be successful, but at the cost of numerous surgical procedures. Growth modulation is a promising new approach to preventing fracture altogether, though further study with larger patient series is necessary. The primary consideration in treatment of CPT is expected union rate and refracture risk. Combined intramedullary and external or internal fixation, especially with cross-union techniques, show most promise. Perhaps most exciting is further research on preventing fracture through guided growth, which may reduce the morbidity of multiple surgical procedures which have been the mainstay of treatment for CPT thus far.

The association between fibular status and frontal plane tibial alignment post-union in congenital pseudarthrosis of the tibia

PURPOSE

Controversy exists regarding fibular status related to tibial alignment after congenital pseudarthrosis of the tibia (CPT) achieves union. We aimed to determine whether fibular status affected frontal plane tibial alignment post-CPT union.

METHODS

Between January 2010 and December 2013, we followed 36 patients treated using a combined surgical technique (mean 6.6 years (2.2 to 9.4)). Outcome measures comprised medial proximal tibial angle, tibial diaphyseal angulation, lateral distal tibial angle (LDTA), relative intramedullary rod length and relative fibula length discrepancy.

RESULTS

The frequency of proximal tibial valgus deformity and ankle valgus deformity were significantly lower in the fibular integrity group than in the fibular un-integrity group (proximal tibial valgus deformity: 2/17 versus 11/19; p = 0.006; ankle valgus deformity: 10/17 versus 18/19; p = 0.016). The mean LDTA was notably higher in the fibular integrity group than in the fibular un-integrity group (81.2° (sd 6.7°) versus 71.3° (sd 6.6°); p < 0.001). A statistically significant difference was observed in relative fibula length discrepancy between patients with fibular integrity (0.06 (0 to 0.11); Malhotra grade 0, n = 6; Malhotra grade I, n = 11) and those without (0.24 (0.01 to 0.36); Malhotra grade 2, n = 2; Malhotra grade 3, n = 17; p < 0.001). Ankle valgus deformity had a significant positive correlation with proximal tibial valgus deformity (r = 0.402; p = 0.015). Patients with an intact and normal length fibula had a lower frequency of ankle valgus deformity than those with an intact but shortening fibula (1/6 versus 9/11; p = 0.035).

CONCLUSION

Shortening or pseudarthrosis of the fibula was associated with ankle valgus and proximal tibial valgus deformities post-CPT union.

LEVEL OF EVIDENCE

III.

A case report of early unilateral external fixation by 3D printing and computer-assisted and secondary bone graft internal fixation in pseudarthrosis of the tibia surgery

Congenital pseudarthrosis of the tibia (CPT) is a rare congenital malformation. It is characterized by a tibial anterior bowing deformity or specific types of non-union, which typically result from abnormal development of the tibia, leading to the formation of local pseudarthrosis. The treatment of CPT is very challenging. The advent of 3D printing and computer-assisted techniques in recent years has provided a new ancillary technique for treatment planning and implementation. This case report describes the successful surgical treatment of a 14-year-old male that presented with a shortened limb deformity. Ahead of elective surgery, 3D printing and computer-assisted techniques were used to provide a 1:1 model of his left tibia, fibula and ankle joint to precisely determine the surgical procedure. The first surgery did not result in complete calcification of the tibial extension area, so a second proximal tibia iliac bone graft and internal fixation surgery was undertaken. Following regular follow-up and rehabilitation, by the 18-month follow-up, the proximal tibial bone graft had healed and the patient had resumed walking with a normal gait. This case report describes in detail the successful use of unilateral external fixation using the Ilizarov technique, 3D printing and computer-assisted orthopaedic surgery in the planning of treatment for CPT.