eMedicine Specialties > Orthopedic Surgery > Pediatrics

Congenital Pseudoarthrosis of the Clavicle

L Andrew Koman, MD, Professor, Chair, Department of Orthopedic Surgery, Wake Forest University School of Medicine

Updated: Jun 11, 2008

Introduction

Congenital failure of formation of the clavicle is a rare disorder. A painless mass over the right clavicle is the most common finding that prompts parents to seek consultation with a physician. Treatment may consist of mere observation or resection of the pseudoarthrosis and osteosynthesis.^{1,2,3,4,5,6,7}

History of the Procedure

In 1930, Saint-Pierre reported congenital failure of clavicle formation. In 1963, Alldred reported 9 cases of congenital pseudoarthrosis of the clavicle.⁸ Surgical intervention generally is recommended, to correct shoulder girdle hypermobility and an unsightly mass. Both problems can be treated by open reduction, resection of the pseudoarthrosis, and bone grafting.⁴ Resection alone produces pain.

Problem

Congenital failure of formation (ossification) of the central portion of the clavicle produces a painless prominence in the anterior superior chest in the absence of trauma. The resultant synovial pseudoarthrosis is usually right-sided. Functional impairment is uncommon in children.

Frequency

Congenital pseudoarthrosis is rare. Fewer than 200 cases have been reported in the English literature. The exact incidence and prevalence are unknown. The abnormality occurs almost entirely on the right side. Involvement of the left side usually occurs with dextrocardia and situs inversus.⁹ Bilateral cases can occur but are rare and are typically associated with genetic syndromes.¹⁰

Etiology

The etiology is unknown, and no relationship with neurofibromatosis has been demonstrated. Abnormalities in aortic arch angiogenesis have been postulated, which would explain, in part, the right-sided distribution. Failure of coalescence of the two primary ossification centers contributes to the pathology.¹¹ Left-sided involvement is seen in patients with dextrocardia and situs inversus. The incidence of associated cervical ribs is 15%. Spontaneous healing is extremely rare.

Pathophysiology

Congenital pseudoarthrosis of the mid portion of the clavicle occurs when an environmental insult or anatomic or mechanical event disrupts diaphyseal membranous ossification. In congenital pseudoarthrosis of the clavicle, the 2 primary ossification centers fail to unite. The 2 portions of the clavicle produced are connected by a fibrous bridge that is contiguous with the periosteum, and a synovial membrane develops.² The predominance of right-sided involvement in the absence of situs inversus suggests that the vascular anlage of the subclavian artery that crosses the first rib just below the pseudoarthrosis site may be involved in the etiology.

Congenital pseudoarthrosis has never been associated with malignant degeneration.

Presentation

A painless mass or swelling over the clavicle is the usual presenting concern. The patient has no history of trauma, and shoulder and arm movement are normal. A family history of similar deformities is rare. Neurofibromatosis rarely is an associated diagnosis. In older children, pain is infrequent but may occur. In the typical presentation, the larger sternal side is tilted anteriorly and superiorly, and the smaller acromial portion curves gently to meet the pseudoarthrosis. The mass usually is painless, range of motion is full, and function is normal. Café au lait lesions usually are not seen.

Indications

Indications for intervention include pain, shoulder girdle instability, and altered self-esteem secondary to an unsightly appearance.

Relevant Anatomy

The clavicle is the first bone to undergo membranous ossification. It connects the sternum to the acromion and provides support for shoulder function.

Contraindications

No major contraindications to intervention exist. However, internal fixation may be compromised due to the size of the patient (and the clavicle).

Workup

Laboratory Studies

In general, laboratory studies are not necessary. Genetic testing is indicated in bilateral cases in which a syndrome is suspected.

Imaging Studies

Plain radiographs¹²
- Anterior, posterior, and apical lordotic views usually are sufficient.
- Pseudoarthrosis of the mid clavicle on the right is easily visualized and has a characteristic pattern, with anterior and superior tilting of the sternal half and a smaller acromial portion.
MRI
- MRI may be used to determine the extent of the fibrous union, the location of the great vessels, and the space available within the thoracic outlet.
- MRI rarely is indicated.

Histologic Findings

Histologic findings consist of synovial-lined pseudoarthrosis.¹¹

Treatment

Medical Therapy

Mere observation may be appropriate. No nonoperative techniques achieve union.

Surgical Therapy

Surgical intervention is indicated for pain, appearance that negatively impacts self-esteem, and shoulder deformity interfering with function.¹³

Preoperative Details

After taking a general history and performing a physical examination, evaluate the right upper extremity for range of motion, stability, and neurovascular function. The patient should be prepared for surgery, and the entire right upper limb prepared free to facilitate mobilization of the clavicle and to observe for neurovascular problems. Prophylactic antibiotics are appropriate if internal fixation is employed. A semisitting or beachchair position may be helpful to obtain exposure.

Intraoperative Details

Surgical steps are as follows:

Expose the clavicle through a transverse incision.
Control bleeding with electrocautery.
Expose the medial and lateral clavicle subperiosteally, excise the sclerotic ends, and resect the pseudoarthrosis.
Determine if end-to-end repair is possible.¹⁴ If not, use a bone graft.
Apply an appropriate-sized compression plate.
Reapproximate the periosteum.
Close the wound in layers.

Postoperative Details

Postoperatively, the patient is immobilized in a sling and swath; alternatively, a shoulder spica may be used for small children if internal fixation is inadequate.¹⁵ The clavicle is protected until union is confirmed clinically and radiographically.

Complications

The major surgical complication is failure of the clavicle to unite. However, in contradistinction to congenital pseudoarthrosis secondary to neurofibromatosis, union is common.

Hardware is removed if painful or unduly prominent. Neurovascular injury is rare but may occur. Infection may occur in the postoperative period.

Outcome and Prognosis

The outcome is usually excellent, with prompt healing, few complications, and normal function.

Future and Controversies

In the future, the true etiology of congenital pseudoarthrosis may be delineated, and its predilection for the right chest will be understood. It is likely that injection with osteoinductive material will convert the pseudoarthrosis to normal membranous ossification or that the application of external bone-stimulating devices will induce osteoprogenitor cells to replace the pseudoarthrosis with normal bone.

References

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Owen R. Congenital pseudarthrosis of the clavicle. J Bone Joint Surg Br. Nov 1970;52(4):644-52. [Medline].
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Ahmadi B, Steel HH. Congenital pseudarthrosis of the clavicle. Clin Orthop. Jul-Aug 1977;(126):129-34. [Medline].
Mooney JF, Koman LA. Bilateral congenital pseudarthrosis of the clavicle associated with trisomy 22. Orthopedics. Feb 1991;14(2):171-3. [Medline].
Gomez-Brouchet A, Sales de Gauzy J, Accadbled F, Abid A, Delisle MB, Cahuzac JP. Congenital pseudarthrosis of the clavicle: a histopathological study in five patients. J Pediatr Orthop B. Nov 2004;13(6):399-401. [Medline].
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Schnall SB, King JD, Marrero G. Congenital pseudarthrosis of the clavicle: a review of the literature and surgical results of six cases. J Pediatr Orthop. May-Jun 1988;8(3):316-21. [Medline].
Grogan DP, Love SM, Guidera KJ. Operative treatment of congenital pseudarthrosis of the clavicle. J Pediatr Orthop. Mar-Apr 1991;11(2):176-80. [Medline].
Beslikas TA, Dadoukis DJ, Gigis IP, Nenopoulos SP, Christoforides JE. Congenital pseudarthrosis of the clavicle: a case report. J Orthop Surg (Hong Kong). Apr 2007;15(1):87-90. [Medline].
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Keywords

congenital failure of formation clavicle, shoulder deformity, chest deformity, dextrocardia, situs inversus, neurofibromatosis, pseudarthrosis

Contributor Information and Disclosures

Author

L Andrew Koman, MD, Professor, Chair, Department of Orthopedic Surgery, Wake Forest University School of Medicine
L Andrew Koman, MD is a member of the following medical societies: American Academy for Cerebral Palsy and Developmental Medicine, American Academy of Orthopaedic Surgeons, American Academy of Orthopaedic Surgeons, American Orthopaedic Association, American Orthopaedic Foot and Ankle Society, American Society for Reconstructive Microsurgery, American Society for Surgery of the Hand, Clinical Orthopaedic Society, Eastern Orthopaedic Association, North Carolina Medical Society, North Carolina Medical Society, Orthopaedic Research Society, Pediatric Orthopaedic Society of North America, Sigma Xi, Southern Medical Association, and Southern Orthopaedic Association
Disclosure: Allergan Grant/research funds study investigator; Wright Medical Consulting fee Researcher

Medical Editor

Mininder S Kocher, MD, MPH, Associate Professor of Orthopedic Surgery, Harvard Medical School/Harvard School of Public Health; Associate Director, Division of Sports Medicine, Department of Orthopedic Surgery, Children's Hospital Boston
Mininder S Kocher, MD, MPH is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Association for the History of Medicine, American Medical Association, American Orthopaedic Society for Sports Medicine, and Massachusetts Medical Society
Disclosure: Smith & Nephew Endoscopy Consulting fee Consulting; ConMed Linvatec Consulting fee Consulting; Covidian Consulting fee Consulting; EBI Biomet Consulting fee Consulting

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

George H Thompson, MD, Director, Pediatric Orthopedics, Rainbow Babies and Children's Hospital
George H Thompson, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Orthopaedic Association, Pediatric Orthopaedic Society of North America, and Scoliosis Research Society
Disclosure: Nothing to disclose.

CME Editor

Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital
Dinesh Patel, MD, FACS is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Association of Physicians of Indian Origin, American College of International Physicians, and American College of Surgeons
Disclosure: Nothing to disclose.

Chief Editor

Dennis P Grogan, MD, Clinical Professor, Department of Orthopedic Surgery, University of South Florida College of Medicine; Chief of Staff, Department of Orthopedic Surgery, Shriners Hospital for Children of Tampa
Dennis P Grogan, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Medical Association, American Orthopaedic Association, American Orthopaedic Foot and Ankle Society, Eastern Orthopaedic Association, Irish American Orthopaedic Society, Pediatric Orthopaedic Society of North America, and Scoliosis Research Society
Disclosure: Nothing to disclose.

Further Reading