Page 380 - Medicine and Surgery

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376 Chapter 8: Musculoskeletal system

Investigations Management
Skeletal survey allows accurate measurement of the long Multidisciplinaryapproachinvolvingphysiotherapy,oc-
bones. cupational therapy and orthopaedic surgery.
Gentle nursing of infant to avoid fractures.

Management Prompt splinting of fractures to prevent deformity.
Patients may develop neurological problems due to Mobilisation to prevent further osteopenia.
stenosis of the spinal canal; this may require surgical in- Correction of deformities if necessary by surgical in-
tervention. Leg lengthening procedures and genu varum tervention.
correction may be considered. New therapies under evaluation include bisphospho-
nates, growth hormone and bone marrow transplant.
Genetic counselling should be offered where appro-

Osteogenesis imperfecta priate.
Definition
Aheterogenous disorder with brittle bones and involve- Bone tumours
ment of other collagen containing connective tissue.

Incidence Metastatic bone tumours
1in 20,000 live births.
Definition
Metastatic cancer is much more common than primary
Aetiology
bone cancer.
Most of the observed phenotypes result from mutations
inoneoftwogenesthatcodefortypeIcollagenprecursor
Aetiology/pathophysiology
proteins(COL1A1andCOL1A2).Bluescleraresultfrom
Two thirds of bone secondaries arise from adenocarci-
a thinning of the sclera, which allows the colour of the
nomas of the breast or prostate. The remainder arise
underlying pigmented tissue to be seen. from carcinoma of the bronchus, adenocarcinoma of
the kidney and thyroid. Metastases usually appear in the
Clinical features marrow cavity, damaging bone both directly through
Features and classification are given in Table 8.4. expansion and indirectly through bone reabsorption.

Complications Clinical features
Hearinglossduetootosclerosis.Thetriadofotosclerosis, Patients may present with bone pain or a pathological
blue sclera and brittle bones is termed van der Hoeve’s fracture. Bone metastases may be the first sign of the
syndrome. primary tumour. There may be a leucoerythroblastic

Table 8.4 Features and classification of osteogenesis imperfecta

Type Inheritance Features
Type I Tarda (mild) Autosomal dominant Fractures are common, sclera are blue and joints are
hypermobile; however deformity is uncommon. Heart valve
disorders may occur
Type II (lethal) Recessive disorder Infants may be still born, or have multiple fractures and
deformities of the long bones
Type III (severe deforming) Normally diagnosed at birth, by 5 yrs of age the child has had
multiple fractures and has developed severe deformity. Few
children survive into adult life and those who do have severe
growth restriction
Type IV (moderately severe) Autosomal dominant Similar to type I without the blue sclera