What’s the difference?
- ‘Osteo’ comes from the Greek word “osteon”, bone. While both Osteo-arthritis and Osteo-porosis may sound similar and both involve musculoskeletal systems in our body, they are actually rather different in terms of how they come about and how they affect our lives Osteoarthritis is a disease that affects the cartilage at the ends of our bones leading to painful movements, stiffness and loss of function. It is convenient to remember it as age-related wear and tear of the joint cartilage.
- Osteoporosis describes the loss of bone mass that increases the risk of fractures of bones.
- Both diseases are under appreciated chronic conditions that if left untreated, may lead to debilitating outcomes.
Osteoarthritis (OA)
Osteoarthritis of the knee is a degenerative condition where the protective cartilage covering our knee joints are worn out and no longer provide the smooth, protective surface for our joints to move. The meniscus is a soft piece of cartilage that sits between the femur and tibia cartilage and acts as a shock absorber. The two menisci in each knee may tear for one reason or another and lose their ability to confer protection to the cartilage. If the torn menisci are not addressed, the cartilage will be subjected to increased mechanical pressure and chemical pressure from bad proteins (inflammatory cytokines). This leads to progressive and accelerated breakdown of this cartilage (osteoarthritis)
Symptoms and risk factors of osteoarthritis
Patients start to develop painful, stiffness and loss of function which affect their daily activities. In the early stages, patients may experience worsening pain with simple physical activities which don’t improve with rest and simple pain killers. Over time, they may start to limp and change their activities to cope with the pain. Some even start to develop deformities of their legs such as bow-leggedness and knock knees. Millions of people around the world are affected by knee arthritis, impacting their basic quality of life and happiness. Patients who do not have much muscle strength to support themselves may find their knees buckling due to pain and experience frequent falls.
While osteoarthritis is a degenerative process related to age, physical activities, genetics and patients body mass, inflammatory arthritis such as rheumatoid arthritis, ankylosing spondylitis, gout, psoriatic arthropathy describes an autoimmune condition where the body fights itself and causes degeneration of multiple joints around the body at a younger age.
X-ray of a patient with rheumatoid arthritis: the right knee is in varus while the left knee is in valgus (wind swept knees). There is severe loss of joints space in both knees with the right knee being significantly worse than the left.
Symptoms and Progression
In the early stages of arthritis, patients may experience intermittent pain which may come and go with certain activities. Knee pain may be accompanied by swelling, stiffness and gradual deterioration of function. Patients may find themselves limping or walking with an unusual gait to overcome their pain. In later stages of arthritis, patients may find that they have become bow-legged or knocked-knees. If symptoms become too severe, many middle-aged patients choose to quit their jobs or retire early as the pain becomes overwhelming.
Diagnosis
Most doctors, physicians and surgeons would take a thorough medical history to determine details about the knee pain: duration, severity, what factors make it better or worse, associated symptoms, effect of arthritis on personal and professional life.
A simple x-ray is performed with the patients standing up to determine the alignment of the knees from the front, the side as well as the top (skyline view of the patella). These different views of BOTH knees while the patient is standing will give information about the alignment of the knees when patients are standing and which of the three compartments of the knee is worn out. If x-ray images are not conclusive enough, an MRI scan of the knee is organised to assess for cartilage wear, meniscus tear and integrity of the different ligaments in the knee.
MRI scan of a knee showing bone marrow oedema and cartilage loss (figure A) and a meniscus tear (Figure B)
Treatment: Medications, physical therapy, lifestyle changes
Non-surgical approaches (medications, physical therapy, lifestyle modifications) are often used first to manage symptoms. Most patients get better with simple treatment such as rest, modifying their physical activities and physiotherapy. They will benefit from simple analgesia such as anti-inflammatory medications (Arcoxia, Diclofenac) as well as those containing opioids (Tramadol). For those who experience pain that affect their sleep, other night medications such as Lyrica or Gabapentin may help with their symptoms.
We usually send patients for physiotherapy and rehab to strengthen their lower limps, stretch out certain muscle groups which are tight and improve their gait and balance.
Surgical interventions (joint replacement, arthroscopy)
In the early stages of arthritis for younger patients, the idea of surgery is to preserve their knee and improve their physical function. Some minimally invasive surgical techniques are performed to restore their torn cartilage as well as to repair any torn meniscus. The menisci are two very important shock absorbers in the knee and their integrity must be restored so they may continue to protect the cartilage.
If patients are middle aged and the condition of their knee is too severe to repair, they may then benefit from joint replacement surgery. Partial and total knee replacements are available for such patients. The decision depends on multiple patient factors such as age, body weight and integrity of their ACL. Your orthopaedic surgeon will go into greater details about the pros and cons of both types of knee replacement surgery and which one would suit you best.
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Osteoporosis
Osteoporosis is a metabolic bone condition characterised by low bone mass and increased risk of fractures. Bones are the major reservoir of calcium in the body and are subjected to constant bone turnover. Like a house of bricks, bone cells are removed (by osteoclasts) then replaced by new bone (by osteoblasts) all the time. In osteoporosis, more bone is removed than replaced by the body. As its microarchitecture is affected, bones becoming more brittle and prone to fractures.
Who gets it?
Most patients with osteoporosis are post-menopausal women. Women are more prone to osteoporosis as they can lose up to 20% of their bone mass in the five to seven years after menopause. The hormone oestrogen protects bones and maintains its healthy turnover. With menopause, there is a dramatic fall in oestrogen production leading to more bone resorption (taken away) and less bone replaced.
Men are also affected by osteoporosis, but this is far less common. Men’s bone health is controlled by both the oestrogen and testosterone hormones. Osteoporosis in men is mostly affected by lifestyle factors and medication.
There are however other factors such as medication, lifestyle and certain disease that also cause osteoporosis.
Lifestyle factors
- Sedentary lifestyle
- Smokers
- Alcoholics
- Low body weight
- Positive family history
Medication causing osteoporosis
- Long term steroids
- Chemotherapy medication
Medical conditions
- Chronic renal failure
- Liver disease
- Cancer
- Rheumatoid arthritis
- Hyperthyroiodism
- Type 1 Diabetes mellitus
Signs and Symptoms
Osteoporosis is described as a silent disease where patients do not know they have it until they experience a bone fracture after a minor fall. Other signs that patients may be experiencing osteoporosis include the following:
- Loss of height or back pain (vertebral compression fractures)
- Hump in the upper back
- Tooth loss (if osteoporosis affects the jaw)
Diagnosis: Bone mineral density (BMD) test
A Dual Energy X-ray Absorption (DEXA) scan is performed to assess the bone mineral density in the hip and spine. The amount of bone in the patient is then compared to that of a healthy 30-year-old of the same gender as well as another person of the same age, gender and weight. This then tells us if the patient has normal bone density or osteopenia/osteoporosis.
Who needs a DEXA scan?
- All women 65 years and older, and all men 70 years and older
- Women under 65 years old and with risk factors (estrogen deficiency, low body mass, Amenorrhoea before 42 years old)
- Men and women of any age with the following risk factors
- Family history of osteoporosis
- Vit D deficiency
- Loss of height
- Alcohol or cigarette use
- Prolonged immobilisation
- Long term steroid use
- Fragility fracture (bony fracture around the hip, shoulder, spine, pelvis or wrist)
- Hyperthyroidism or hyperparathyroidism
Comparative Analysis
Blood tests for osteoporosis
Your doctor will organise a series of blood tests looking at your liver, kidneys and calcium stores in your body. Low levels indicate a high risk of osteoporosis.
Is osteoporosis dangerous?
- Osteoporosis has been known as the Silent Disease. In the early stages of the disease, there may not be any obvious symptoms. As osteoporosis progresses, it is associated with back pain, fractures, poor balance, loss of height and a reduced life span. Patients are also known to have shortness of breath and trouble with their lungs (smaller lung capacity due. To compressed spine).
- Over the last 30 years in Singapore, the cases of hip fractures have increased five times in women aged 50 and above, and only less than double in men of the same age group. Studies.
Management and treatment of Osteoporosis
Lifestyle
A healthy lifestyle that includes regular weight bearing exercises, supported by a well balance diet that provides sufficient calcium and vitamin D is crucial in maintaining bone health and strength.
Vitamin D helps your body absorb the calcium in your diet. You can make your own vitamin D through sunshine on your skin. Allow healthy amounts of sunshine on your arms and legs several times a day, this is best done for about 5 to 30 minutes each time.
Exercise helps strengthen your muscles and bones while improving your balance and gait. It’s never too late to start exercising! There are all types of safe exercises for patients with osteoporosis:
- weight bearing aerobic exercise: brisk walking, skipping, dancing, tai chi
- strength and resistance training: gentle weights training, resistance bands
- flexibility exercises: yoga, pilates
- stability and balance exercises: yoga, pilates
Find the safest, most enjoyable activities for you and your overall health. Do avoid high impact exercises or bending and twisting movements which may cause injury and fractures in osteoporotic bone. Before you start, do consult a doctor or health professional if you are unsure about your bone health and what exercises to do.
Dietary Calcium intake
Adequate intake of calcium is important to maintain bones and bodily functions.
Everyday calcium is lost through urine, faeces, sweat and the shedding of hair, nails and skin. Calcium may be replaced by eating calcium-rich foods such as dairy products, calcium fortified products and even non-dairy food. Calcium is best absorbed when taking in small amounts throughout the day, so spread your calcium intake over breakfast, lunch and dinner.
Here are some easy guidelines for selecting foods high in calcium:
- Dairy products have the highest calcium content. Dairy products include milk, yogurt and cheese. A cup (8 ounces) of milk contains 300 mg of calcium. The calcium content is the same for skim, low fat and whole milk.
- Dark green, leafy vegetables contain high amounts of calcium. Broccoli, kale and collards are all good sources of calcium, especially when eaten raw or lightly steamed. (Boiling vegetables can take out much of their mineral content.)
- A serving of canned salmon or sardines has about 200 mg of calcium. It's found in the soft bones of the fish.
- Cereal, pasta, breads and other food made with grains may add calcium to the diet. Look for cereals that are fortified with minerals, including calcium.
- Besides cereal, calcium is sometimes added to fruit juices, soy and rice beverages and tofu. Read product labels to find out if a food item has added calcium.
It is best to get all your calcium and vitamin D from food and sun exposure alone. If you are unable to get enough of either nutrient, consider a calcium or a vitamin D supplement.
Medication for osteoporosis
Bisphosphonates are the commonest medication used to treat osteoporosis. They are often taken with calcium and Vitamin D. As mentioned above, bones are always renewing itself through a metabolic process. Our body breaks down older bone cells and absorbs it with the help of osteoclast cells. At the same time, it builds new bone cells with the help of osteoblasts cells. Bisphosphonates reduce the breakdown and absorption of old bone cells and encourage bone to keep building. This helps to increase the strength of bone and reduce the risk of fractures. Bisphosphonates may be taken as a weekly medication.
The use of bisphosphonates is often limited to about 4 years or so before patients’ medications are stopped. This is to allow the body to reset itself and begin removing some of the old bone cells which are unhealthy. Bone which is too hard after prolonged use of bisphosphonates may become brittle like glass. Doctors often repeat the BMD after about 2 years of bisphosphonate use to track the progression of bone health. If no improvement is seen, other medications may be used to treat osteoporosis.
Conclusion
Prevention is always better than cure. If you feel that you are at risk of developing either osteo-arthritis or osteo-porosis, please seek medical attention from your local doctor, an orthopaedic surgeon or physiotherapist. It’s best to identify any medical condition early so that appropriate measures may be taken to address your symptoms before they get out of hand.
Most treatment options begin with conservative techniques and surgery is only required as a last resort.
