Clinical Significance Of Other Bone Diseases: Hypertrophic Osteoarthropathy And Paget’s Disease Of Bone
Hypertrophic Osteoarthropathy Clear manifestation
Hypertrophic Osteoarthropathy In Its Physical Presentation
Also known as hypertrophic pulmonary osteoarthropathy, Marie-Bamberger’s syndrome etc, is an acquired disorder characterized by clubbing of the fingers and toes, painful thickening of the ends of long bones such as the tibia and radius and varying degrees of arthritis. In most cases, it is secondary to other underlying disorders, rarely it may be idiopathic and at times it runs in families. The exact mechanism of development of the lesions is not clear.
Pulmonary lesions: Chronic suppuration such as bronchiectasis, lung abscess and empyema, carcinoma lung, pleural mesothelioma, alveolo-capillary block syndromes, fungal infections and chronic fibroid tuberculosis.
Cardiovascular lesions: Cyanotic congenital heart disease, infective endocarditis, aneurysm of the Aorta or its branches.
Other conditions: Chronic malabsorption states, ulcerative colitis, regional ileitis, cirrhosis liver, hepatic abscess and thyrotoxicosis.
Onset is very insidious in the vast majority of cases, but it is rapid in malignancy of the lung or pleura and infective endocarditis. It is usually bilateral but unilateral clubbing may develop in aneurysm of the subclavian artery. The manifestations include clubbing of the fingers and toes, symmetrical painful enlargement of distal ends of bones at the wrist and ankle and intermittent swelling and painful limitation of joint movements. In a few cases, true arthritis, fibrous ankylosis and deformity may result.
When hypertrophic osteoarthropathy is associated with marked thickening of the skin of the limbs and face, this is called pachydermoperiostosis.
In all secondary cases, the primary cause should be detected and corrected. This leads to resolution of the bone changes. Nonsteroidal anti-inflammtory drugs relieve pain.
Paget's Disease Of The Bone
Paget’s Disease Of Bone (Osteitis Deformans)
This is a rare disease of unknown etiology, characterized by enlargement, softening and deformity of several bones, seen after the age of 40 years, more commonly in men. Though, this disease is common in the west, it is seen only rarely in Indians especially. The involvement is localized in the majority of cases but may be widespread.
Pathology: There is increased formation and destruction of bone which is disorderly. This results in a high rate of bone turnover. The bone is highly vascular and functional arteriovenous shunts develop, resulting in a high cardiac output state. The marrow is replaced by highly vascular fibrous tissue. Pelvis, femur, skull, tibia, and vertebrae are affected in the order of frequency.
Many cases are asymptomatic and detected on routine radiological examination. Symptoms include pain on weight bearing, progressive enlargement of the skull, deformities of the affected bones, pressure on the nerves which can pass through bony canals (Cranial nerves, spinal nerves and spinal cord) and rarely the development of high output cardiac failure state. Though the bones are thickened, they are weaker than normal. The femur and tibia undergo bowing and other deformities due to weight- bearing. The overlying skin is warm due to increased vascularity. Deafness, optic atrophy, and paraplegia are rare neurological complications. Serum alkaline phosphatase is grossly elevated. Serum Calcium and phosphorus are normal. Urinary hydoxyproline is increased during the active phase of the disease.
Complications: These include fracture, progressive deformity, cranial nerve palsies (especially deafness), spinal cord compression, degenerative joint disease, high output cardiac failure when the diease is extensive and in longstanding cases, osteogenic sarcoma.
Diagnosis: The diagnosis is based on clinical features and is confirmed by radiography. The bones appear larger, chalky white and non-homogenous in the skiagram.
Treatment: Asymptomatic localized lesions have to be left alone. Symptomatic relief of pain is achieved by aspirin, indomethacin or corticosteroids. Human calcitonin in a dailu dose of 0.5 mg subcutaneously for 6 months (or salmon calcitonin 100 MRC units/day) promptly relieves bone pains and helps in reducing the turnover of bone. Mitrhamycin in a dose of 25- 50 ug/Kg given intravenously for 10- 14 days is effective. This drug inhibits bone resorption. It produces myelosuppression and a hemorrhagic tendency. Diphosphonates (disodium etidronate) in a dose of 5- 10 mg/Kg/day also reduced bone turnover and bring about clinical relief in some cases. However, they are less effective than calcitonin. Calcitonin and etidronate can be combined.
Immobilization should be avoided since it leads to hypercalcemia and hypercalciuria. The onsent of osteogenic sarcoma should be looked for in longstanding cases.
© 2014 Funom Theophilus Makama