Congenital Pseudarthosis of Radius and Ulna

Dr. Abdul KarimFCPS II TraineePGMI/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.