CONGENITAL PSEUDARTHROSIS of the TIBIA

Pathology

• Fibrous Hamartoma surrounding bone

• Associated with NF in over 50%

• No NF at CPT site

Where is the disease?Bone vs Periosteum

Observation:

Slow bone remodelling of pin holes

Remodelling is a periosteal function

New theory (Paley 1995:

CPT is a periosteal disease and not a bone disease (the bone is affected secondarily)

Hermanns-Sachweh B et al: Vascular Changes in the Periosteum of Congenital Pseudarthrosis of the Tibia.

Pathology Research and Practice 201, 305-312, 2005.

• Neural cells forming a tight sheath around the periosteal arteries reminiscent of the way Schwann cells surround peripheral nerve fibers.

• Result: accumulation of nerve cells in the periosteum cause narrowing or obliteration of the periosteal vessels.

• Result: periosteum undergoes hypoxemic degeneration resulting in the formation of a thick fibrous cuff. This leads to impaired oxygen and nutrient supply to the subperiosteal bone with secondary atrophic bone changes.

Is this theory really new?

• Codivilla (Italy) 1903

autogenous osteoperiosteal graft

• Cambras (Cuba) 1977

periosteal graft from mother

CPT: Classifications

• Camurati 1930• Badgley 1952• Boyd 1958• Apoil 1970• Andersen 1973• Crawford 1986• Crawford 1999• El-Rosassy-Paley 2000

I II III

El-Rosassy-Paley Classification

Type I

• Atrophic, narrow bone ends• Mobile• No previous surgery

El-Rosassy-Paley Classification

Type II

• Atrophic, narrow bone ends• Mobile• Previous surgery

El-Rosassy-Paley Classification

Type III

• Hypertrophic, wide bone ends• Stiff Previous surgery

El-Rosassy-Paley Classification

Type I Treatment

Lateral

AP

preop postop

Flexible IM nail3 year follow-up

Fassier-Duval Telescopic Nail

LLD

Type II Treatment

Bone transport

Acute shortening

CPT resection

acute shortening

re-lengthening

bone transport healed

ReFx follow-upIM rod

Treatment

Type III • Closed distraction + compression

• Gradual deformity correction

• ± Lengthening

• ± IM Rod (late)

distraction of CPT follow-up

pre-op compression healed

Treatment

Type III • Closed distraction

• Gradual deformity correction

• ± Lengthening

• ± IM Rod (late)

distraction of CPT follow-up

Periosteal & Bone Grafting with IM rod and Ilizarov

Union: 20/20

1997-200820 patients treated

RESULTS

Don’t ForgetBracing until Skeletal Maturity