Pathophysiology The patient, a 92-year-old female, was brought into the hospital on

Pathophysiology

The patient, a 92-year-old female, was brought into the hospital on August 29, 2021, after falling in the floor and being found by a family member. The patient has many ongoing comorbidities and has a history of adenoma of the colon. The admitting diagnosis of a right hip fracture will first be discussed at the cellular level, which will include pertinent assessment data, diagnostics, lab values, signs and symptoms. The comorbidities of degenerative bone disease and vitamin D deficiency will then be related to the patient’s admitting diagnosis of a right hip fracture.

Admitting Diagnosis: Right Hip Fracture

With aging, many physiological changes decrease within the body, especially within the bones. Once these processes occur, it is easier to break or fracture a bone, such as with a fall. According to the Johns Hopkins Fall Risk Assessment Tool (JHFRAT), this patient is a high falls risk with a score of 14. The patient must be monitored closely so that she does not fall again and consequently fracture another bone. She is receiving physical therapy to help regain strength and normal gait, as well as improve balance. Bones have important functions and many vital components such as osteoclasts, osteoblasts, osteocytes, osteoprogenitor cells, blood vessels, nerves, collagen, proteins, lipids, glycosaminoglycans, phosphate, calcium carbonate, and calcium fluoride (Morgan, 2019). This patient has many predisposing factors that led to weakening of the bone, such as age, ethnicity, and hormonal changes with being a woman in the postmenopausal period (Padilla Colón et al., 2018).

The four types of bone cells, osteoclasts, osteoblasts, osteocytes, and osteoprogenitor cells, function in the development and preservation of bone (Morgan, 2019). Osteoprogenitor cells are undifferentiated and are found in the growing part of the bone. Osteoprogenitor’s transform into osteoblasts during bone growth or in the presence of a bone injury such as a fracture. They also restore bone tissue that has been worn-out. Osteoblasts have the main function of building the bone through ossification and calcification. Osteoid formation is the process of ossification and calcification is when calcium salts are carried into the bone tissue. Osteocytes are mature have the function of maintenance of the matrix and the release of calcium into the serum. Osteoclasts reabsorb the matrix of the bone and allow calcium and phosphate to be released out of the bone. This patient showed slightly low calcium levels of 8.0 mg/dL, with the normal range being 8.2-10.2 mg/dL (Van Leeuwen & Bladh, 2017). This shows that osteocytes, which function in the release of calcium into the blood, is decreased. Also, the decrease in estrogen resulting from menopause causes an increase in in osteoclast activity, leading to faster bone reabsorption (Morgan, 2019).

Aging also increases the formation of advanced glycation end-products (AGEs) (Padilla Colón et al., 2018). AGEs stimulate osteoclasts activity, which results in increased bone reabsorption, modification of proteins, and the disturbance of bone restoration. The decrease in the patient’s calcium level likely contributed to the induction of bone mass loss. It is recommended that women 51 and older receive a daily calcium amount of 1,200 mg (Mayo Clinic, 2020a). The patient is on 1.25 mg of ergocalciferol, which is a supplement of vitamin D2. This helps the patient to absorb calcium and keep the bones strong (University of Michigan Health, 2020).

Hormones also play a vital role in the maintenance and development of bone, which includes calcitonin, parathyroid hormone (PTH), and vitamin D (Morgan, 2019). PTH aids in preventing serum calcium levels from falling and phosphate levels from increasing. This patient is not on a PTH supplement, but it would be ideal to help with healing and prevention of further bone breakdown. PTH upholds calcium levels by allowing calcium release from the bone, kidney conservation of calcium, increased intestinal absorption, and by reducing phosphate levels in the blood. On the other hand, calcitonin works in the opposite way by ensuring that serum calcium levels are not too high. It is secreted from the C cells of the thyroid gland and does not allow for calcium to be released into the blood if levels are not low enough. Calcitonin also helps the body absorb calcium that is received through nutrition. Vitamin D is another important factor in the maintenance of calcium, but that will be discussed later with the patient’s comorbidity of vitamin D deficiency.

Typically, hip fractures are diagnosed with an X-ray, MRI, or CT scan (Mayo Clinic, 2020b). This patient had an X-ray on her right hip on August 29, 2021, that showed a displaced right femoral transcervical fracture. As a result of this patient being found alone in the floor and not knowing the extent to her injuries, a thorough history was needed. This included how she fell, when, where, symptoms, and how long ago it happened (Morgan, 2019). One of the main symptoms of a hip fracture is pain, even following treatment, which this patient presented with. The patient presented to the emergency department with pain, but also had pain scores of 10 and 6 throughout the shift. Pain from a fracture is a result of the distortion of mechanosensitive nerve fibers that help in the innervation of bones (Mitchell et al., 2018). This distortion sends pain impulses to the brain so that the inflammatory process can begin. This includes neurotransmitters, cytokines, and nerve growth factors. The excitement of nociceptors of the bone are impacted by the release of prostaglandins, bradykinin, endothelin, and nerve growth factor. Ectopic nerve sprouting also occurs because of neurotrophic factors being released. This results in pain from increased innervation of the bone marrow, bone mineralization, and periosteum.

Treatment of a hip fracture includes surgery, rehabilitation such as physical therapy, and/or medication (Mayo Clinic, 2020b). This patient had a right hip hemiarthroplasty on September 1, 2021. This is a partial hip replacement where only half of the hip is replaced. The patient is also completing in-patient physical therapy which will help regain strength of the right hip, as well as balance and range of motion. The patient was also prescribed hydrocodone-acetaminophen for moderate pain as needed. It is important that the patient receives an analgesic prior to physical therapy to ensure best outcomes.

Comorbidity: Degenerative Bone Disease

Degenerative bone disease, also known as osteoarthritis, can lead to pain, disability, and increased risk of injury (Chen et al., 2017). This disease is most caused by age, specifically ages 65 and older. Chondrocytes, which are present in the cartilage, manifest increased oxidative stress from aging, resulting in transformed mitochondrial function. Degenerative bone disease from aging also causes TGF-ß and receptor action of ALK1 through ALK5 to increase, leading to the manifestation of a matrix metalloproteinase (MMP) TGF-ß pathway. Collagenases, stromelysins, gelatinases are inhibited by TIMP-1, TIMP-2, a-2-macroglobulin. This causes cartilage to be damaged (Ling & Bathon, 2021). The MMP pathway becomes overwhelmed by this process, leading to bone breakdown. The presence of inflammation is also seen in degenerative bone disease, specifically in the joints. IL-1ß, TNF-a, and chemokines lead to the initiation of NF-kB in synovial cells and cartilage cells, causing inflammation (Chen et al., 2017).

Albumin and protein play a role in the development of bone. Low albumin can lead to a decreased bone mineral density, causing weakened bones and joints as seen in degenerative bone disease (Kunutsor et al., 2019). This patient had an albumin level of 1.5 g/dL, with the normal range being 3.7-5.1 g/dL (Van Leeuwen & Bladh, 2017). Low albumin can indicate inflammation (Soeters, 2018). Capillary permeability manifests with inflammation allows for the leakage of albumin, swelling the interstitial spaces, which causes the circulation of albumin to be widely spread. As stated above, inflammation is a characteristic of degenerative bone disease, which can explain in part why the patient has low albumin levels. Protein is also a vital component of the structure of bone (Wallace, 2019). Half of bone is protein, contributing to its strength and mass. Amino acids and minerals are needed to sustain the continuous osteoblast and osteoclast activity within bones. If this is not maintained, it can lead to issues such as degenerative bone disease. It is normal for aging to decrease protein levels which can impact the structure of the bone. This patient had a total protein level of 3.6 g/dL, with the normal range being 6-8 g/dL (Van Leeuwen & Bladh, 2017).

The patient’s age, gender, low albumin and protein levels, and inflammation all lead to the weakening of bones, which made it easy to fracture when she fell. Degenerative bone disease is usually diagnosed through a physical exam, X-rays, MRI, and lab tests (Mayo Clinic, 2021). X-rays can show narrowing of the joint spaces which indicates cartilage loss. An MRI is more detailed than an X-ray, as it can show a more descriptive image of bones, tissues, and cartilage. Lab tests include analyzing joint fluid. To complete this procedure, the healthcare provider aspirates joint fluid with a needle, and it is sent for testing. This can show inflammation and narrow down the cause of degenerative bone disease. This patient had an X-ray on her hip on August 29, 2021, which showed degenerative bone breakdown present in the right hip, along with the fracture. The patient was diagnosed with degenerative bone disease before being admitted to the hospital for her hip fracture, but this shows that degenerative breakdown is present within her bones.

Degenerative bone disease cannot be cured, but treatments can help alleviate symptoms (Mayo Clinic, 2021a). Treatment options typically include medications, topical solutions, rehabilitation, surgery, or injections. This patient has hydrocodone-acetaminophen (Lortab) prescribed to help alleviate moderate pain. The patient is also doing in-patient physical therapy for mainly the right hip follow surgery, but it is also helping her degenerative bone disease by strengthening and improving mobility. Occupational therapy can help perform activities of daily living that are effective by degenerative bone disease, such as gripping a household appliance. Transcutaneous electrical nerve stimulation (TENS) can provide an electrical stimulation to the affected joint, alleviating pain. Cortisone or lubrication injections can be provided, which will alleviate pain and provide extra support in the joints. If the degenerative bone disease is severe, a joint replacement can be completed to completely remove the affected joint and replace it with a new one.

This patient was complaining of pain in the right knee when lifting it, and she rated it a 6 on a scale of 1-10. She had decreased strength and resistance on that leg as a result. This is likely due to the degenerative changes that have occurred in the knee. The patient is also prescribed diflonac sodium (Voltaren), which is applied topically every day on her knee to help with pain and joint stiffness. She also is prescribed lidocaine (Lidoderm) patches to be applied every 24 hours transdermal to her knee, also acting as an analgesic to help alleviate pain.

Comorbidity: Vitamin D Deficiency

Vitamin D encompasses two forms which include vitamin D2, ergocalciferol, and vitamin D3, cholecalciferol (Morgan, 2019). Vitamin D is inactive until it is converted which can be from intestinal absorption or skin production. In the intestine dietary vitamin D is absorbed through the jejunum by bile salts and lymphatic vessels. It is important to maintain adequate intake of vitamin D, which is 800 IU for this patient (Mayo Clinic 2021b). Dietary sources of vitamin D include fish, liver, and milk (Morgan, 2019). Exposure to sunlight stimulates 7-dehydrocholesterol into vitamin D. Intestinal and skin production lead to vitamin D being synthesized in the liver to 25-hydroxyvitamin D3. It then proceeds to the kidneys where it transforms into 1,25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3. These forms of vitamin D are involved in bone mineralization and maintenance. The 1,25-dihydroxyvitamin D3 promotes parathyroid hormone, allowing for calcium and phosphate to be reabsorbed from the bone.

Ergocalciferol, which is absorbed in the intestine, can be decreased due to aging on the intestine (Dumic et al., 2019). Intestinal microbiota function is altered, and secretions are decreased. Hypochlorhydria or achlorhydria are typically present, which is when stomach acid is low. This can lead to decreased calcium absorption and ultimately diminished bone mineral density, which can cause weak bones that are easy to injure. In addition, cell proliferation and differentiation of enterocytes are increased in the elderly, which can also lead to malabsorption of vitamin D3 in the jejunum. It is not uncommon to see small bowel ischemia, bacterial overgrowth, and decreased pancreatic function with age. Those factors can also influence absorption of vitamin D3.

Aging decreases vitamin D metabolism and causes a deficiency (Hill & Aspray, 2017). Normally, vitamin D can be produced in sufficient amounts just from exposure to ultraviolet rays, but in the elderly population, they tend to stay inside more and do not get adequate vitamin D (Morgan, 2019). Their ability to transform 7-dehydrochoesterol, which is present in the skin, to vitamin D is also diminished (Hill & Aspray, 2017). This can lead to inadequate vitamin D intake, which weakens the bone and leads to increased risk of fractures and injuries. Vitamin D contributes tremendously to bone strength by protecting them and helping the body absorb calcium (National Osteoporosis Foundation, 2018). Osteoclasts and osteoblasts are constantly remodeling the bone and vitamin D is needed to do so (NIH, 2021).

Vitamin D also has the potential to decrease inflammation (NIH. 2021). The cells that are involved in inflammation, such as proteins, have vitamin D receptors and they have the potential to translate 25-hydroxyvitamin D to 1,25-hydroxyvitamin D. If vitamin D is insufficient and not present to bind to these cell receptors, inflammation can take place. Vitamin D supplementation can help with this process by binding to the cell receptors and decreasing inflammation.

The primary way to diagnose vitamin D deficiency is by a health history and blood tests (Cleveland Clinic, 2019). The healthcare provider will analyze the symptoms the patient is presenting with and measure 25-hydroxyvitamin D levels in the blood. If low levels are found, treatment options will be put into place.

Treatment options for vitamin D deficiency include supplements to maintain adequate calcium level (Cleveland Clinic, 2019). The doctor may suggest more exposure to sunlight or increase foods that are rich in vitamin D to the diet, but the main treatment method is supplementation. This can include vitamin D2, ergocalciferol, or vitamin D3, cholecalciferol. This patient is on ergocalciferol supplementation of 1.25 mg, which helps maintain calcium, phosphate, and parathyroid hormone levels (Vallerand & Sanoski, 2017).

Conclusion

In conclusion, the patient’s admitting diagnosis of a right hip fracture had many factors that were causative of weak and brittle bones, making it easy for the patient to develop an injury. The patient’s comorbidities of degenerative bone disease and vitamin D deficiency were discussed at the cellular level and related back to the admitting diagnosis, primarily by the weaking of the bones. The patient’s age has a major influence on her bone health and risk of falls, so she must be monitored closely so it does not occur again. The patient’s pain level was a result of her hip fracture, but with analgesics and physical therapy, it should continue to improve. The patient is in the recovery phase, meaning she is getting better. Her surgical incision is healing properly and there are no signs of infection.

References

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