Improper or insufficient nutrition is one of the leading causes of weak and vulnerable bones. For example, a recent study conducted by Loris Pironi (1) suggested that parenteral nutrition (intravenous or central – venous feeding that is employed in patients with chronic diseases interfering with oral food intake or those who underwent major surgeries) is one of the leading causes of weak bones and resulting bone diseases. Pironi conducted this study in patients who were on parenteral feeding for a period of at least 6 months. Results suggested that:
- 35% of all the enrolled patients reported frequent episodes of intense bone pain
- 10% reported one or more bone fractures
“Bone disease was present in most of the patients on HPN, was of severe degree in one-half of them and symptomatic in one-third. The BMD Z-score appeared predictive of the risk of fracture”
It can be safely assumed that improper diet or unhealthy lifestyle contributes to bone diseases and disorder by affecting remodeling as well as reconstruction of the bones. This article will discuss some of the most common and important bone diseases and risk factors that aggravate the risk in a normal subject.
Osteoporosis is referred to weak and porous bones that are incapable of maintaining normal bone functions. In vast majority of cases, the disease is progressive but silent (until bones get extremely weak and fracture results with tremendous amount of pain and discomfort).
- Risk factors
Primary risk factors include female gender, history of smoking, low body weight, advanced age and menopause (or other hormonal aberrations). Any factor that interferes with the appropriate mineralization of bone can lead to osteoporosis (one of the most common bone disorder). Research (6) suggested that after the age of 50 years, almost 20% individuals develop moderate osteoporosis.
Calcium and Vitamin D supplements are generally recommended in addition to healthy or balanced diet and regular physical activity. Other pharmacological options include bisphosphonates and hormone replacement therapy in elderly subjects.
The primary complications of well-developed osteoporosis are increased risk of pathological fractures, poor healing of fractures and dislocations. According to the study conducted by O. Johnell and JA Kanis (2), approximately 9.0 million fractures were attributed to advanced osteoporosis (in year 2000). The most common sites of advanced involvement were forearm (1.7 million), hip (1.6 million), and clinical vertebral fractures (1.4 million).
- Risk factors
- Osteogenesis Imperfecta
Osteogenesis imperfecta as the name suggests, is a disorder of bones with genetically pattern of inheritance. This disorder is marked by:
– Bone fractures that are mostly pathological (which means without any force of impact or injury).
– The severity of lesions vary from person to person (some people develop fractures readily and frequently while others develop less than 3 fractures in the entire lifetime).
The classic and somewhat unfortunate fact is the diagnosis of this disorder is extremely difficult (so far no single test can determine the presence or absence of this disease). The diagnosis is usually performed by a variety of medical, physical, biochemical testing and family history. Sometimes study of collagen and genes is required to diagnose the condition.
The management or treatment is usually multi-dimensional and complex interplay of bone strengthening exercise, pain medicine and physical therapy. In order to reduce physical and psychological dependence, various devices and instruments can be used like wheelchairs or braces. Surgery is usually reserved for extreme cases. Bisphosphonate therapy is the most preferred pharmacological therapy while gene therapy is currently under research for the possible cure of this bone disorder (3).
- Paget Disease Of Bone
Paget disease of bone is another common musculoskeletal issue that may also involve other systems like hearing. This disorder is characterized by high growth potential of bones that primarily affect long bones of the body. The bones not only increase in size but are also weak and vulnerable to injuries, fractures and dislocations. It is marked by excessive bone resorption with abnormal bone formation that eventually replaces the marrow with fibrous and vascular tissue (4).
The exact paths physiology is unknown. However, it is generally believed to be multi-factorial (with strong role of inheritance). In some cases, the disease is preceded by a viral infection. Most commonly involved bones are skull, spine, long bones of the leg and pelvic bones. In most cases, one or two bones are involved more than others (systemic or generalized weakness of bones is uncommon).
- Sign and symptoms
Classic sign and symptoms that points to the pathogenesis of this disease are
– Bone pains that is much intense in involved bones but may be generalized.
– Enlarged bones that are evident on radiological scans (also associated with bone pains).
– Broken bones due to porous and weak architecture of inner bone matrix.
– Damaged cartilage in joints that leads to arthritis and high risk of fractures and dislocation of joints.
- Risk factors
– It is far more common in males as compared to females.
– Physiologic aging is one of the strongest risk factors associated with pager disease of bone.
The diagnosis of pager disease of bone is made mainly on the basis of radiological exam (like X-rays, CT scan) and serological testing (blood tests, enlarged serum creatinine and alkaline phosphatase).
The treatment is mainly pharmacological to stop the process of abnormal bone formation and dissolution. Proper exercise and healthy diet also plays a significant role in the prognosis of disease. The overall prognosis is good provided appropriate management and treatment options are taken and disease is identified earlier in the course.
Osteomalacia is an acquired condition (in most cases) caused by deficiency of vitamin D in adults (vitamin D deficiency in children is referred to as rickets). Moderate to severe deficiency of Vitamin D impairs the bone building process, leading to soft and weak bones that may present as (5):
– Moderate to severe bone pain
– Weakness of muscles
– Changes in normal gait
– Lower muscle tone and impaired grip.
- Risk factors
Following conditions significantly increase the risk of developing osteomalacia.
– Low exposure to sunlight (vitamin D is synthesized by skin cells upon sun exposure).
– Certain surgeries (especially gut surgeries increase the risk of malabsorption of minerals that leads to weak and vulnerable bones)
– Renal or hepatic failure (by interfering with the activation of Vitamin D synthesized by the skin cells).
– Certain drugs like Phenobarbital and phenytoin (and other anti- seizure drugs) can also lead to osteomalacia.
Treatment is mainly to replenish the body stores of calcium and vitamin D by oral or intra-muscular supplementation. Additionally, it is also important to manage the primary source of illness (for example renal failure can also lead to secondary deficiency of vitamin D by interfering with the activation process).
- Risk factors
Fracture refers to a breech or break in the continuity of bones. Although, any bone of the body can get fractured if the force of impact is severe, the most commonly fractured bones are long bones of the body (like humerus, ulna, radius, femur, tibia and fibula). In some susceptible individuals, the spinal and pelvic bones can also get fractured (as a result of accidents, falls or assault).
- Sign and symptoms
The sign and symptoms are generally suggestive of a severe injury (swelling, hematoma formation, severe pain and discomfort, limited range of motion and history of assault or injury).
- Risk factors
– Certain occupational or recreational activities increase the risk of fractures (like football, base ball, basket ball).
– Chronic steroid abuse
– Osteoporosis and other disorders of bone mineral density
Management of fracture is dependent upon the site, severity and nature of fractures. Most bones can be stabilized by immobilization. However, in case of compound fractures or complicated fractures (when bone is broken into fragments), open surgical reduction or stabilization is done.
- Sign and symptoms
- Fibrous Dysplasia
When fibrous tissue (a type of scar tissue) replaces the normal bone, the disorder is referred to as fibrous dysplasia. Virtually any bone can be affected but most common sites are thighbone (femur), shinbone (tibia), humerus, pelvic bones, ribs, skull and facial bones. It may also occur as part of a more complex issue with endocrinological involvement of thyroid gland (manifesting as signs of hyperactivity of thyroid gland), adrenal gland (manifested by appearance of skin pigmentation also known as cafe au lait spots) or pituitary gland (presenting with signs of precocious puberty).
- Sign and symptoms
The scar tissue is soft and lacks the strength and stability of bones. Therefore, the soft bone thus produced increases the risk of injuries and trauma to the bone. Fibrous dysplasia is an inherited condition that may be missed at the time of birth but most cases are diagnosed by adolescence. Most common sign and symptoms are bone pain, deformities and fractures.
So far no curative therapy has been devised. Most current treatment regimen aims at alleviating the symptoms and decreasing the risk of injuries.
- Sign and symptoms
- Osteitis Fibrosa Cystic
Hyper-secretion of certain hormones like parathyroid gland leads to excessive resorption of bones leading to osteitis fibrosa cystic bone lesions. The primary role of this hormone is to control the serum levels of calcium, phosphorous and vitamin D that eventually control the bone mineralization.
The primary cause of osteitis fibrosa cystic is parathyroid secreting tumors. Most characteristic symptoms are:
– Bone pain and areas of localized tenderness in bones
– Development of deformities
– Hyper- parathyroidism also leads to complications like renal stones and other side effects.
– High serum calcium levels also cause nausea vomiting and constipation.
Diagnosis of osteitis fibrosa is usually made by X- rays (jaw scans and bone scans are abnormal). All blood investigations like calcium, phosphorous and alkaline phosphatase also abnormal.
Osteitis fibrosa is managed by removal of parathyroid gland by surgical resection. In individuals who are not candidate for surgery, various pharmacological options are available to control serum concentration of calcium.
- Osteochondritis Dissecans
It is yet another rare bone condition in which the cartilage and bone separates from the edges of the long bones due to interruption in the blood supply. The primary patho-physiological feature of this disorder is an unstable joint as a result of separation of affected bony fragment. Most commonly involved joints are knee, elbows, ankles and pelvis. The dislodged pieces of bone are referred as “joint mice”. The primary sign and symptoms are:
– Clicking or cracking sensation whenever the affected joint is moved.
– Limitation of range of motion.
– Weakness of muscles.
– Pain and stiffness that aggravates after mild to moderate physical activity.
Young males and females who are highly active in sports and other physical activities are most vulnerable to develop this joint condition. X-rays and CT scan are the mainstay diagnostic modalities in addition to a detailed history and comprehensive physical examination.
Surgical removal of the affected piece of bone is required in addition to traditional pain relieving medications like non-steroidal pain medications. In addition, lifestyle modification, bed-rest and physical therapy are also important cornerstones of therapy.
Osteopetroses is a rare condition of bone in which the old bone is not recycled by the body. As a result, the overall bone density is increased. The classic symptoms are:
– Thick and vulnerable bones that are liable to get fractured with minimal trauma
– Without management and with severe disease, osteopetroses may culminate in death during infancy
– The overall growth pattern of bone is abnormal (also known as marble bones)
– Production of blood cells is also impaired due to narrow marrow spaces
– Loss of hearing, transient or permanent loss of vision and facial paralysis are some complications that may occur in patients as a result of impingement or narrowing of nerve spaces or columns.
The diagnosis is dependent upon the X-rays, serological testing and other types of radiological examinations in addition to the history and physiological assessment of bones.
There is no curative treatment available to date. However, various management options (including pharmacological and conservative) can help in decreasing the duration of complications. Most successful management options are:
A) Corticosteroid therapy to increase the production of blood cells.
B) Bone marrow transplantation to manage anemia.
C) Surgical decompression of nerves to manage facial paralysis or hearing impairment.
- Bone tumors
Bone tumors may develop as primary malignancy or may occur as secondary metastatic lesions. Primary bone tumors may be benign (with better prognosis and lesser risk of side effects) or malignant (with worst prognosis and higher rate of complications). The classification of bone tumors is generally done according to the site of involvement and aggressive nature.
Chondroblastoma is categorized under benign tumors that usually involve terminal ends of long bones (like upper limb bones or thigh bones). It is most common in individuals younger than 25 years. The exact cause or patho-physiological course of this tumor is not entirely known. However, following sign and symptoms point to the diagnosis:
– A limp in one or both of the limbs without any history of trauma or injury
– Muscular weakness
– Stiffness of joints
– Atrophy of muscles
The diagnosis of this tumor variety is usually delayed since the growing mass is imbedded within the bones and is difficult to identify on physical examination. X-rays, CT scan and biopsy are utilized as the primary diagnostic modalities and treatment is mainly carried by combination of resection, bone grafting and curettage.
- Secondary Bone Tumors
Secondary bone tumors are referred to as metastatic lesions from other primary tumors. Breast cancer, lung cancer and prostate cancer are most likely to metastasize to bones. Most common signs and symptoms are dependent upon the severity and spread of primary tumor.The management options are mainly dependent upon the staging of tumor and hormonal sensitivity. Radiotherapy and chemotherapy are usually employed in addition to surgical resection of primary tumor.
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2. Johnell, O., & Kanis, J. A. (2006). An estimate of the worldwide prevalence and disability associated with osteoporotic fractures. Osteoporosis International, 17(12), 1726-1733.
3. Rauch, F., & Glorieux, F. H. (2004). Osteogenesis imperfecta. The Lancet, 363(9418), 1377-1385.
4. Roodman, G. D., & Windle, J. J. (2005). Paget disease of bone. Journal of Clinical Investigation, 115(2), 200-208.
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