Congenital pseudarthrosis of the clavicle is a rare disorder that is usually discovered during the first months of life, characterized by a bone defect in the middle third of the clavicle. It is an isolated congenital malformation of the shoulder girdle that should be distinguished from the nonunion observed in familial cleidocranial dysostosis and the nonunion associated with von Recklinghausen neurofibromatosis1. At diagnosis, pseudarthrosis of the clavicle is generally asymptomatic, but it can be responsible for aesthetic issues as the child grows and functional symptoms related to more intense activities. Surgical repair of pseudarthrosis of the clavicle is indicated for both cosmetic and functional reasons2,3. The surgical approach most commonly used consists of resection of the pseudarthrosis, placement of an iliac crest bone graft, and internal fixation4,5. When surgical resection is performed early and when periosteal repair is possible, internal fixation is not required6. Postoperative complications are rare and essentially consist of nonunion4-9.
Since 2000, Masquelet et al. have developed a technique for bone regeneration in the metaphyseal and diaphyseal regions of long bones10,11. This technique was first used in adults after trauma with bone loss12,13 and in cancer surgery after bone resection14. More recently, it has been introduced in the treatment of congenital deformities and is currently used by some surgeons to treat congenital pseudarthrosis of the tibia15.
We describe the use of the Masquelet technique with internal Kirschner-wire fixation in the reconstruction of a congenital pseudarthrosis of the clavicle. The patient and her family were informed that data concerning the case would be submitted for publication, and they provided consent.
Although congenital pseudarthrosis of the clavicle causes few symptoms2,17, the cosmetic deformity is generally progressive with growth17. Surgery is usually performed for cosmetic reasons or relief of symptoms, such as shoulder pain or functional disorders2,18. This deformity is rarely associated with thoracic outlet syndrome or brachial plexus nerve compression19-21.
The surgical treatment with the highest success rate consists of resection of the pseudarthrosis with iliac crest bone graft and internal plate fixation2,4,6,22. Good results have also been reported with other methods, including internal Kirschner-wire fixation17,23, threaded Steinmann pins8, or external fixation18. Although one study reported that internal plate fixation achieved more rapid bone union with a lower complication rate compared with internal fixation with fully threaded pins24, this type of internal fixation can lead to plate breakage or plate fixation failure25. Moreover, other complications (e.g., fracture) may occur in the screw hole following a minor impact7, or the plate may be prominent, requiring its removal24. Internal plate fixation requires a second operation for removal of the plate, with opening of the entire scar and a higher risk of fracture in the screw holes, which is why we chose pin fixation despite the known risks of infection and nonunion with this type of material24.
To avoid such complications and improve bone union, we used the Masquelet technique. This method has been described with good results in the treatment of segmental bone loss in children14,15. The two-step technique comprises the two main elements necessary to achieve union: presence of a membrane comparable with periosteum and a bone graft. Grogan et al.6 also reported good results of periosteal repair without internal fixation. This technique is easier to perform in younger patients. In our case, the induced membrane created around the cement spacer acted like periosteum to achieve bone union around the graft. The intramedullary Kirschner-wire fixation allows covering of the bone extremities with cement. The induced membrane is therefore cylindrical and not interrupted by the plate.
Bone graft is also necessary. Cadilhac et al.4 reported nonunion in three of eight patients treated with fixation without grafting, while union was achieved in a similar group of nine patients treated with fixation and grafting. Bone-grafting may improve union after resection. Elliot and Richards26 used a bovine cancellous xenograft (Tutobone) to avoid the potential complications of iliac crest bone graft, but both of their cases resulted in treatment failure with substantial osteolysis and failure of incorporation of the graft material.
The induced-membrane technique requires two separate operations, while the other procedures previously used for congenital pseudarthrosis of the clavicle require a single operation, but the two-step technique avoids the disadvantages of plate fixation. The presence of cement placed around the pin in the first operative step also provides primary stability, thereby avoiding material failure.
The induced-membrane technique may be used in revision surgery to avoid the use of a free vascularized fibular transfer. This type of vascularized autologous graft is rarely indicated for the treatment of clavicular nonunion27-30. Only one case has been described in the treatment of congenital pseudarthrosis of the clavicle in children9, corresponding to a case of surgical revision after massive lysis of the bone graft. Since a free vascularized fibular transfer is a complex technique with invasive bone harvesting, this method is rarely used. Instead, the Masquelet technique may be performed in this setting.
The Masquelet procedure allowed fully remodeled bone reconstruction in our patient with congenital pseudarthrosis of the clavicle. We believe that this procedure achieves and maintains union in the early treatment of congenital pseudarthrosis of the clavicle.
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.