Congenital Pseudarthosis of Radius and Ulna
Dr. Abdul Karim FCPS II Trainee PGMI/LGH, Lahore
Definition
Pseudarthosis is a false joint associated with abnormal movement at the site.
Congenital pseudarthrosis refers to a spontaneous fracture which progresses to non union.
This is rarely presented at birth but commonly developed during first 18 months of life.
Commonly affected Bone
Tibia is the most frequently affected bone
Associated with congenital anterolateral tibial bowing in neurofibromatosis which progresses to psudoarthrosis.
Rarely affected Bones
Fibula
Radius, Ulna
Clavicle
Femur
Radius
Congenital pseudarthrosis of the radius/ulna is an extremely rare condition.
Genetics
Autosomal dominant disorder. Neurofibromatosis type 1 (von Recklinghausen’s disease). Mutation of the NF1 gene on chromosome 17. The NF1 gene is a tumour suppressor gene; It encodes a protein, neurofibromin which modulates signal transduction through the ras GTPase pathway.
In all cases reported, Pseudarthosis of the radius occurred in the distal third.
Features
Deformity is the most common complaint
Anterior or Posterior bowing of Radius/Ulna.
Pathological fractures.
Gender
Male /female ratio is 8 / 1
Diagnosis
X-Rays
AP and Lateral view of the radius, ulna is sufficient to make accurate diagnosis.
Treatment
Numerous treatment options have been explored with varying degrees of success and the reports have demonstrated successful healing.
Boyd
Dual onlay bone grafting Advantages:
Restores length Viselike grip on the osteoporotic distal fragment Increases size of distal end of proximal fragment.
Resulting in satisfactory union.
Kameyama and Ogawa
Complete resection of involved radius. Periosteum and soft tissue removal. Free Vascularized fibular transfer. Operation is delayed untill skeletal maturity. Forearm brace until surgery is performed.
Ulna
Congenital pseudarthrosis of the ulna in neurofibromatosis is extremely rare.
Literature
Only 18 patients with NF and isolated ulna Pseudarthosis have been reported in literature.
Features
The ulnar pseudoarthrosis produces
Angulation of radius
Forearm shortening
Dislocation of radial head
Diagnosis
X-Rays
AP/lat of the radius, ulna is sufficient to make accurate diagnosis.
Treatment
Bone grafting with or without internal fixation
Creation of one-bone forearm
Free vascularized fibular grating
Ilizarov compression-distraction technique
Radial osteotomy for correction of bowing
Bone grafting usually fails Significant radial bowing develops in very young children, so early surgery is indicated.
Associated Radial head dislocation
Excision of radial head
Synostosis (one-bone forearm)
Congenital Pseudarthosis Clavicle
Congenital Pseudarthosis Clavicle
Rare anomaly Present at birth Usually involves middle third Right side more common (80%)
Features
Palpable and visible prominence at birth
No history of trauma
No signs and symptoms of fracture
Each end is separately mobile
Hyper mobility of the shoulder
Features
Dropped shoulder, arm closer to midline
May be painful or painless
The main complaint is deformity
Usually right clavicle
10% bilateral, rarely left
Ethiology
Familial (AD) transmission reported
No association with NF
Two theories
Ist Theory
Intrinsic failure of development
Clavical develops in two seperate masses by medial & lateral ossification centers.
Faliure of ossification of the precartilageneous bridge.
2nd Theory
Extrinsic pressure on the clavicle
Right side predominance result of higher subclavian artery on that side Cervical rib; pseudarthrosis at site where artery crosses the rib
Radiographic Features
Defect in central 1/3
Bone ends usually hypertrophic
No evidence of healing or periosteal reaction
Differential Diagnosis
Cleidocranial dysostosis
Non union after fracture clavicle.
Treatment
Mainly operative Indication:
Cosmetic appearance Pain
Timing of surgery
3-6 year of age
Treatment
Remove atrophic, sclerotic bone ends
Suturing periosteum of ends together ORIF with plates/screws/graft
High union rate, unlike tibia
Tricortical Bone Graft
Fracture is reduced after debriding fibrous nonunion tissue and removing atrophic, sclerotic bone ends. Resultant defect is measured, and appropriately sized tricorticocancellous bone graft is obtained from iliac crest
Congenital dislocation of radial head
Congenital dislocation of radial head is rare. It should be suspected that radial head has been dislocated for a long time. Ulna fracture should be ruled out. Abnormally small and misshapen Radial head.
Etiology
Congenital dislocation of the radial head may be familial, especially on the paternal side .
May be associated with chondroosteodystrophy.
Types
Anterior dislocation of radial head.
Less common
Posterior dislocation of radial head.
more common
Clinical Feature
May be painful or painless.
Mild loss of extension/flexion.
Loss of supination.
X-ray
The radial shaft is abnormally long.
Ulna usually is abnormally bowed.
The radial head dislocated .frequently posteriorly but some time anteriorly.
The capitellum may be small.
Radial head may be small or absent.
Treatment
< 1 / 2yrs
Lengthening of the ulna or shorting of the radius.
Reconstruction of the annular ligament.
Treatment
>2yrs
Resection of the radial head.