Question

Mary-Lou’s family was happy with the management plan established by the doctor as Mary-Lou was progressing quite well. She was using notepads to jot down reminders, a pillbox to keep her medication organized and a calendar to record appointments. Her family members were helping her with routine tasks such as cooking and paying bills. She was feeling much happier and did not have to rely on alcohol to go to sleep. On one particular day she was feeling so good she decided to walk to her GP appointment alone. On her way there she stumbled over a branch and fell. She felt excruciating pain in her hip. A passer-by called an ambulance and she was taken to the emergency department at the Royal Melbourne hospital. An X-ray revealed that she had broken the neck of her femur and had to have surgery to repair it. Mary-Lou wondered whether this was linked to the crepitus she had been experiencing in her joints. Her joints did feel quite stiff and painful lately. The specialist explained to Mary-Lou that the crepitus was likely due to degeneration of her cartilage and said that the fracture might have been due to weakened bones. He told her he would like her to have a bone mineral density test to measure her bone density. The DEXA scan gave a T-score of -3.0. Mary-Lou is now given bisphosphonates and told to increase her daily intake of calcium.

Question 6 Discuss how the aetiology of Mary Lou’s joint disease differs from the other joint disease we covered in BIOL122.

Answer 1

Mary Lou is suffereing from both osteoarthritis and osteoporosis at the same time. Osteoarthritis is a degenerative joint disease characterized by the degeneration of the articular cartilage and proliferation of new bones. The crepitus or the grating sensation experiencing by her affected the hip joint with pain, stiffness and reduced movement of the affected joint. On the other hand she has osteoporosis which is a bone disorder where bone loses its minerals and fibres from its matrix. The loss of minerals and fibres from the matrix decreases the bone mass and causes osteoporosis. Mary Lou has been diagnosed with a bone mineral density test where the T score of -3 reveals the condition of osteoporosis. So she has been recommended to take biphosphonates and increase her daily intake of calcium . Osteoporosis is an age related order and is considered as 'the silent thief' which is caused due to many factors such as imbalance of hormones like calcitonin (produced by thyroid gland) and parathormone (produced by parathyroid gland), deficiency of calcium and vitamin D, decrease of sex hormones such as estrogen, prolonged treatment of cortisone and pain relieving drugs, alcohol abuse, etc. When there is not enough calcium in the blood stream the body attempts to pull Ca2+ from the bone. This thins and weakens the bone and causes osteoporosis and bone becomes fragile. This is what had happened to Mary Lou as she stumbled over a branch and felt breaking the neck of her femur.

The joint pain and stiffness experiencing by the lady is due to osteoarthritis which differ from other joint disease like rheumatoid arthritis, gout, etc. The main points of differences are as follows:

(i) While other joint disease like rheumatoid arthritis is an autoimmune disorder in which the immune system is misdirected and start acting against the 'own body' but osteoarthritis is not an autoimmune disorder, rather a degenerative disease of joints. In case of rheumatoid arthritis, the primary symptom of inflammation of synovial membrane take place. As a result, the membrane thickens and synovial fluid increases, exerting pressure that causes pain. But in case of osteoarthritis, breakdown of articular cartilage occurs that cushions the joints and the wearing down of cartilage causes the bones to rub against each other.

(ii) The other joint disease may be inherited, but osteoarthritis more likely to develop due to overweight, joint deformities, diabetes, gout and traumatic injuries.

(iii) Other joint disease like in gout, inflammation of joints occurs due to accumulation of uric acid crystals, but no such things occur in osteoarthritis.

(iv) Other joint disease like Rheumatoid arthritis is a systemic disease which means it not only affects the joints, but also affect entire body including lungs, heart, eyes, etc. But osteoarthritis is limited to degeneration of joints only with symptoms like bone spurs, stiffness, tenderness, loss of flexibility, grating sensation, etc.

(v) Osteoarthritis is less symmetrical whereas other joint disease are frequently more symmetrical.