Musculoskeletal & Integumentary System Disorders & Medications

Module 7

Calcium Homeostasis & remodeling

• dynamic balance between resorption & deposition

constant turnover

• skeleton acts as calcium reservoir regulated by endocrine feedback loops

cellular players

• osteoblasts build bone matrix while osteoclasts resorb mineralized tissue

• Blasts are the builders

• Clasts are the cleavers

Primary Hormones

• parathyroid hormone, calcitonin, and active vitamin D control flux

Parathyroid hormone (PTH)

• Secreted by parathyroid glands in response to low serum calcium

parathyroid functions

• stimulates osteoclasts

  • activates bone resorption to releases stored calcium into bloodstream

• renal conservation

  • increases calcium reabsorption in kidney tubules, reducing urinary loss

• activates vitamin D

  • stimulates renal conversion of calcidiol to calcitrol for gut absorption

Calcitonin

• secreted by thyroid parafollicular cells in response to high serum calcium

calcitonin functions

• inhibits osteoclasts

  • rapidly slows bone breakdown to prevent hypercalcemia

• promotes deposition

  • encourages calcium incorporation into bone matrix

• counter-regulatory role

  • acts as a physiological antagonist to PTH to protect skeletal mass

Vitamin D (Calcitriol)

• essential steroid hormone governing mineral absorption & bone mineralization

Vitamin D (Calcitriol) functions

• intestinal absorption

  • directly enhances dietary calcium & phosphate absorption in gut

• bone mineralization

  • ensures adequate mineral ions available for hydroxyapatite crystal formation

• deficiency impact

  • leads to osteomalacia or secondary hyperparathyroidism

bone remodeling process

• continuous lifelong process: old bone is replaced by new bone

• balance is key

• healthy bone = balanced activity of osteoclasts and osteoblasts

• bone strength depends on this equilibrium

osteoclasts

• break down/resorb bone

osteoblasts

• build new bone (deposition)

when osteoclast activity > osteoblasts activity

• net bone loss occurs

• leads to decreased bone mass & weakening of bone structure

osteopenia

• is bone loss but not severe T-score

• (-1 to -2.5)

osteoporosis

• bone loss but substantial T-score

• (-2.5 or lower)

What is a T-score?

• A comparison of a person's bone mineral density to that of a healthy young adult.

Dual-Energy X-ray Absorptiometry (Bone mineral Density DEXA)

• calculates T-score

• sends to types of X-ray beams

  • One absorbed by soft tissue, the other bone

  • by subtracting the difference, tells you how dense

DEXA recommendations

• no widely accepted recommendations on how often

  • 65 yo should obtain baseline (some sources)

  • regular repeat scans are controversial

  • high risk patients may need earlier & often

Osteopenia (low bone mass)

• a condition where bone mineral density is lower than normal but not low enough to be classified as osteoporosis

• consider a precursor

• T-score between -1.0 and -2.5

• moderate risk of fracture; higher than normal but lower than osteoporosis

• focus on lifestyle changes:

  • weight bearing exercise, adequate calcium and vitamin D intake, and monitoring

Osteoporosis (severe bone loss)

• A progressive disease characterized by significant bone mineral density reduction and deterioration of bone structure, leading to fragility

• T-score of -2.5 or lower

• high risk of fracture, particularly in the hip, spine, and wrist, often from minor trauma

• requires lifestyle changes PLUS medical intervention (medications to strengthen bones, fall prevention, and monitoring

osteopenia & osteoporosis risk factors

• age: increased risk with age (especially >50 years)

• sex: female (especially post menopausal

• family history: genetic predisposition

• low body weight/ BMI

• sedentary lifestyle: lack of weight bearing exercise

• smoking & excessive alcohol

• medications: steroids, anticonvulsants, proton pump inhibitors

• hormonal imbalances

  • decreased estrogen/ testosterone (postmenopause, hypogonadism)

  • increased parathyroid hormone (hyperparathyroidism)

• nutritional deficiencies: calcium & vitamin D deficiency

• chronic diseases: rheumatoid athritis, chronic kidney disease, malabsorption

osteoporosis treatment

• proper nutrition

  • vitamin D & calcium rich diet

• lifestyle changes

  • ETOH & smoking cessation

• weight bearing exercises

• fall prevention to help prevent fractures

• 
  

osteomalacia/rickets

• characterized by an abnormally high ratio of osteoid (inadequately mineralized bone matrix) to mineralized bone

• bone formation progresses to osteoid formation but calcification does not occur; the result is soft bones

  • pain, bone fractures, vertebral collapse, bone malformation

Osteomalacia etiology

• two main causes:

  • vitamin D metabolism

    • Deficiency of vitamin D lowers the absorption of calcium from the intestines

      • lack of utilization of calcium, not lack of calcium

    • could also be just a lack of dietary calcium

  • renal tubular phosphate loss

    • hereditary defect of the renal tubules, leading to decreased reabsorption of phosphate & therefore reduced serum phosphate levels

Osteomalacia treatment

• oral supplements: vitamin D, calcium or phosphate supplements, depending on the individual case

osteomalacia symptom management

• wearing braces to reduce or prevent bone irregularities

• surgery to correct bone deformities (in severe cases)

• adequate exposure to sunlight

paget disease

• “bowing of legs”

• radiograph of the fibula & tibia of a patient demonstrating the effect of advanced proliferate paget’s disease

pagets disease pathology

• chronic condition of bone turnover characterized by disorder of the normal bone remodeling process

  • excessive breakdown of bone tissue followed by abnormal bone formation

  • normal bone marrow is replaced by vascular, fibrous, connective tissue that leads to formation of larger, disorganized, & weaker bone tissue

• most commonly affecting: skull, femur, tibia, pelvic bones, & vertebrae

Pagets disease symptoms

• bone pain → fractures

• skeletal deformities: bowed legs, fronto-occiptial skull enlargement

• nerve damage: hearing loss, visual abnormalities

• cardiac abnormalities: shortness of breath

pagets disease treatment

• meds

  • bisphospnates work by controlling the excessive breakdown and formation of bone that happens in pagets disease

  • calcitonin- promotes the formation of new bone

• exercise: to building bones, prevent wt gain, keep joints mobile

• surgery:

  • reposition of bones that are fractured

  • joint replacement

osteomyelitis patho

• infection of the bone; acute or chronic

• 2/2 direct penetration, skin infections, bloodstream infection (primarily in children) or contagious spread from adjacent wound

osteomyelitis s/sx

• chills, fever, malaise, bone pain, poor incisional would healing and closure, drainage, localized tenderness, redness & swelling

osteomyelitis diagnosis

• I.D. causitive organism via blood cx, bone aspiration (typically s.aureus); may be visualized with routine debridement; CT scan, MRI

osteomyelitis treatment

• difficult to treat

• IV abx (long course) followed by PO

• debridement, amputation with clean margins

activity intolerance

• the amount of physical activity a person can perform without injury or excessive exertion

• no enough physical or psychological energy reserves to endure to complete ADL

• assessment:

  • have patient recount normal activites & level of tolerance of fatigue

  • formal assessment tool like Humana activity profile

fatigue

• the sensation that comes with having exhausted those energy reserves

• it is a state experienced by everyone at some time in life. it is subjective

• can be acute or chronic

• treatment is symptomatic

Osteoarthritis

• Degeneration and loss of articular cartilage, sclerosis of bone underneath cartilage, and formation of bone spurs (osteophytes)​

• Also referred to as degenerative joint disease​

• Incidence increases with age​

• Primary disease is idiopathic

• Characterized by local areas of damage and loss of articular cartilage, new bone formation of joint margins, subchondral bone changes, and variable degrees of mild synovitis and thickening of the joint capsule​

• Manifestations​

  • Pain, stiffness, enlargement of the joint, tenderness, limited motion, and deformity

osteoarthritis treatment

• meds

  • NSAIDS

  • acetaminophen

  • Duloxetine (Cymbalta)

  • topicals like biofreeze, diclofenac, etc.

• therapy; PT/OT assistive devices

• low impact exercises

• surgery & procedures

• joint injections- corticosteroids (reduce inflammation) or hyaluronic acid (lubrication)

• total joint replacement - removes the damaged parts of joint and inserts a prosthesis made of metal and plastic

Rheumatoid Arthritis

• chronic autoimmune systemic disease

• peak incidence 40-50 years of age

• thought to be genetic

• 70-80% have an antibody called Rheumatoid Factor (RF)

• Manifestations are joint pain, swelling, redness, warmth, deformity, loss of function, and joint stiffness

• usually bilateral & symmetrical

• nodules in hands and feet in later stages

RA treatment

• therapy: PT/OT assistive devices

• low impact exercises

• surgery & procedures: synovectomy, tendon repair, joint fusions, total joint replacement

• meds

Synovectomy

• surgery to remove the imflamed lining of the joint (synovium) can help reduce pain and improve the joints flexibility

tendon repair

• inflammation and joint damage may cause tendons around joint to loosen or rupture

joint fusion

• surgically fusing a joint may be recommended to stabilize or realign a joint and for pain relief when a joint replacement isn’t a option

total joint replacement

• removed the damaged parts of joint and inserts a prosthesis made of metal and plastic

Drugs for treating Rheumatoid Arthritis (RA)

• NSAIDS

• glucocorticoids

• disease modifying antirheumataic drugs DMARDS

  • conventional synthetic nonbiologic (traditional) DMARDS

  • biologic DMARDS

  • Target synthetic DMARDS

Gout

• metabolic disorder characterized by elevated uric acid levels in blood resulting in deposistion of irate crystals in synovial fluid and joint tissues

• high serum: > 8.5mg/dL Uric Acid

• mostly seen in males, particularly AA

Gout Symptoms

• intense pain comes on suddenly - often in the middle of the night or upon arising

• inflammation: redness, swelling, and warmth over the joints

Gout Treatment

• anti-inflammatory

  • NSAIDs

  • Colchicine

  • corticosteroids

• Manage uric acid:

  • block uric acid production - allopurinol

  • improve uric acid removal - probenecid

Gout treatment - dietary recommendations

• cherry consumption is associated with lower risk of gout attacks

• Dietary restrictions

  • Purine restricted diet

    • avoid foods & beverages w/high levels of purines

    • organ meats (kidney, liver, etc)

    • seafood includes anchovies, sardines, mussels, scallops, trout &tuna

    • red wine, beer, & red meat

    • sugary drinks

• low impact exercises

Muscular Dystrophy

• multiple types but most common is Duchenne’s or DMD

• Genetic disorder - produce progressive deterioration of skeletal muscle because of mixed muscle cell hypertrophy, atrophy, and necrosis

• progressive, usually manifest in early childhood as weakness, abnormal posture or joint immobility

• no cure, treatment is supportive

  • therapy, braces, breathing assistive devices, mobility aids

• death normally occurs from respiratory or cardiac involvement in young adulthood

Soft tissue injury

• include injury to muscle, ligaments & tendons

• trauma

  • contusion

  • hematoma

  • laceration

• management

  • contusion - elevation & ice; if hematoma forms - may need aspiration, pain management

  • laceration - cleanse area and close wound (suture, staples derma bond), apply sterile dressing, assess need for tetanus immunization

Arthropod Infestation: Scabies

• A mite, Sarcoptes scabiei, burrows into the epidermis

  • transmitted person to person, includes sexual contact

  • healthcare facilities via sheets (can live up to 2 days on sheets)

  • affected areas: interdigital web of the finger, flexor surface of the wrist, inner surface of the elbow, axilla, nipple, penis, belt line, and gluteal crease

  • main symptom pruritus (itching of the skin) & accompanying bites on skin

• Diagnosis - skin scraping showing + mites, ova, or feces

• treatment - topical medication (permethrin, malathion) applied on entire body after bathing. leave on for 12 hours

Arthropod Infestation: Lice

• lice - Pediculosis , insects that ive off of human blood

  • cannot survive outside the host

  • types:

    • Pediculus humanus corporis (body lice), Phthirus pubis (pubic lice), and Pediculus humanus capitis (head lice)

    • Spread via close personal contact

Arthropod Infestation: Lice diagnosis/treatment

• presence of lice or nits, pruritus, papules, and wheals

• treatment

  • eradicate louse & nits on body/clothing/bedding

  • shampoos or topical preparations of malathion or other pediculicides

  • may require multiple treatments

  • discard hairbrush, combs, etc

allergic contact dermatitis

• inflammation of the skin

• cell-mediated type IV hypersensitivity, such as to poison ivy

• usually, mild erythema but can be vesicle or bullae

• location & pattern can help identify cause

irritant contact dermatitis

• caused by chemicals irritating skin

  • sopas fragrances, harsh chemicals etc

• can be classified as subjective, acute, chronic, and chemical burns

• characterized by dryness & erythema or edema, inflammation & vesicles

contact dermatitis treatment

• patch test

• remove allergen, treat symptoms; if systemic effects may need corticosteroids or antihistamines

Atopic dermatitis (aka atopic eczema)

• itchy, inflammatory skin disorder

• poorly defined erythema with edema, vesicles & weeping at the acute stage and skin thickening (lichenification) in the chronic stage

• although often described as an immunoglobulin IgE-mediated hypersensitivity (atopic) disease, allergic causation is difficult to document

• viewed as a skin disease that predisposes to allergies

Nummular Eczema

• Idiopathic but common to have a history of allergy-related disorders​

• Lesions are coin shaped, papulovesicular patches mainly involving the arms and legs. ​

• Lichenification and secondary bacterial infections are common. ​

• Mostly chronic, with weeks to years between exacerbations. ​

• Exacerbations are more frequent in the cold winter months.

Eczema treatment

• remove allergen if indicated

• anti-pruritic creams/lotions

• topical emollients

• topical cortiocosteroids

• may need systemic meds like corticosteroids or antihistamines

• may need immunosuppressive agents in severe cases (cyclosporine, tacrolimus, and azathioprine

• phototherapy (use of UV light for flare ups, itching, redness)

Acne Vulgaris background information

• Issue with pilosebaceous unit, which comprises a tiny vellus hair, hair follicle, and sebaceous gland

• Comprised of non-inflammatory and inflammatory lesions

• Non-Inflammatory – comedones (whiteheads and blackheads)

• Inflammatory – Papules, pustules, and nodules

• Acne vulgaris is most common type

Acne Vulgaris Etiology

• Cause unknown, possible genetic

• Possible contributing factors include: ↑ sebum production, ↑ proliferation of the keratinizing epidermal cells forming sebaceous cells, colonization/proliferation of Propionibacterium acnes, and inflammation.

• Diagnosed as mild, moderate, or moderately severe

Acne Vulgaris treatment

• Treatment

  • Mild - Topical retinoids, benzoyl peroxide, and azelaic acid 

  • Moderate – same as mild + systemic antibiotics

Rosacea background information

• Chronic inflammatory process that occurs in adults between the ages of 30 and 50 years

• Fair skinned people, most common in white women >30 y/o

Rosacea Etiology

• Unknown, but believed to be an inflammatory process accompanied by vascular instability with leakage of fluid and inflammatory mediators into the dermis

what are the 4 types of rosacea

• Erythematotelangiectatic (flushing and persistent central facial erythema)

•  Papulopustular (inflammatory)

•  Phymatous (thickening of the skin with irregular surface nodularities and enlargement)

•  Ocular (involving the eyes)

starts as “blushing” evolves into permanent dark red erythema of nose and cheeks

rosacea treatment

• Topical metronidazole and azelaic acid, topical and systemic abx

• If rhinophyma is present can be treated using surgical methods, including electrosurgery, laser ablation, dermabrasion, cryosurgery, and excision

Psoriasis background information

• Common, chronic inflammatory skin disease characterized by circumscribed, red, thickened plaques with an overlying silvery-white scale.

• Incidence lower in warmer, sunnier climates

Psoriasis Etiology

• Genetic component; apparent association of arthritis and psoriasis

• Activated T lymphocytes produce chemical messengers that stimulate abnormal growth of keratinocytes and dermal blood vessels. Accompanying inflammatory changes are caused by infiltration of neutrophils and monocytes. 

• Köbner reaction

Psoriasis Patho

• Increased epidermal cell turnover with marked epidermal thickening (hyperkeratosis)

• Permanent damage to capillary beds even in the presence of remission or resolution

Psoriasis Types

• Plaque-type psoriasis (most common)

• Guttate psoriasis

• Pustular psoriasis (localized and generalized)

• Erythrodermic psoriasis

Psoriasis assessment

• Primarily located on elbows, knees, and scalp

• Primary lesions are sharply demarcated, thick, red plaques with a silvery scale, vary in size/shape. In darker skinned people, plaques may appear purple. Lesions may have excoriation, thickening, or oozing.

• Auspitz sign

Psoriasis Treatment

• NO CURE

• Goal: Sign and symptom management and suppression

• Topical: Emollients, keratolytic agents, coal tar products, anthralin, corticosteroids, and calcipotriene.

• Systemic: phototherapy, photochemotherapy, methotrexate, retinoids, corticosteroids, and cyclosporine