Metabolic Bone Disease Flashcards
1
Q
Paget’s disease: what is it
A
- LOCALISED DISORDER of BONE TURNOVER - LONG BONES + SKULL
- INCREASED BONE RESORPTION - FOLLOWED by INCREASED BONE FORMATION - bone turnover not coupled
- Leads to DISORGANISED BONE = BIGGER, LESS COMPACT, MORE VASCULAR, MORE SUSCEPTIBLE to DEFORMITY + #
2
Q
Paget’s disease: presentation
A
• PT. > 40YRS w/ BONE PAIN
* DEEP SEATED BORING PULSATING PAIN * NOTHING RELIEVES IT, EXERCISE HAS NO EFFECT
• Occasionally presents w/ BONE DEFORMITY, EXCESSIVE HEAT OVER PAGETIC BONE, NEUROLOGICAL COMPLICATIONS e.g. nerve deafness
- BONE PAIN + LOCAL HEAT
- BONE DEFORMITY/#
- HEARING LOSS esp. if unilateral, HEADACHE
- PELVIS = HIP PAIN
- SKULL = HEARING LOSS, HEADACHES
- SPINE = COMPRESSION of NN. ROOTS - PAIN, TINGLING, NUMBNESS of LIMB/S
- LEG = WEAKENING BONES cause them to BEND (bowlegged), enlarged/misshapen leg bones put extra stress on nearby joints - OA in KNEE/HIP
COMPLICATIONS:
* # + DEFORMITIES * OA * NEUROLOGIC PROBLEMS - NERVE COMPRESSION * HF * RARE DEVELOPMENT of OSTEOSARCOMA in AFFECTED BONE
3
Q
Paget’s disease: aetiology
A
- FHx = STRONG GENETIC COMPONENT: 15 - 30% FAMILIAL (Loci of SQSTMI)
- AGE = > 40YRS
- SEX = M > F
- RESTRICTED GEOGRAPHIC DISTRIBUTION - ANGLO-SAXON ORIGINS
- ENVIRONMENTAL TRIGGER - poss. CHRONIC VIRAL INFECTION w/I OSTEOCLAST (suspect MMR - incidence falling w/ childhood immunisation + less virulent form nowadays)
4
Q
Paget’s disease: investigations/diagnosis
A
- ISOLATED ELEVATION of SERUM ALKALINE PHOSPHATASE - commonest presentation nowadays
- X-RAY + ISOTOPE BONE SCAN (triple phase scan)
- Rare to have symmetric Paget’s
5
Q
Paget’s disease: management
A
- LIFESTYLE = PREVENT FALLS, ADEQUATE CALCIUM + VITAMIN D in DIET (esp. if taing bisphosphonate), REGULAR EXERCISE
- MEDICAL = IV BISPHOSPHONATE THERAPY - ONE-OFF IV ZOLENDRONIC ACID
- No real side-effects as it’s given once; pt. don’t tend to re-present as it stops Paget’s for years (amount of years is variable, but pt. are elderly so don’t tend to come back)
- ASYMPTOMATIC = NO EVIDENCE TO TREAT asymptomatic Paget’s UNLESS in SKULL/SPINE/AREA REQ. SURGICAL INTERVENTION
- NO Rx = if based SOLELY on ALKALINE PHOSPHATASE
- HEARING TEST
- SURGERY = #, JOINT REPLACEMENT, REALIGN DEFORMED BONES, REDUCE PRESSURE on NN.
6
Q
Rickets + Osteomalacia: what is it
A
- RICKETS = GROWING CHILD
* OSTEOMALACIA = ADULT (closed epiphyseal lines)
7
Q
Rickets + Osteomalacia: presentation
A
RICKETS CHILD:
* BONE PAIN * SKELETAL DEFORMITIES - SOFT WEAK BONES, BOWING of LEGS, THICKENING of ANKLES, WRISTS, KNEES * DENTAL PROBLEMS - WEAK TOOTH ENAMEL, DELAY in TOOTH ERUPTION, INCREASED CAVITY RISK * FRAGILE BONES - INCREASED # RISK * POOR GROWTH + DEVELOPMENT - HEIGHT RESTRICTION, MUSCLE WEAKNESS (resulting in waddling gait, delay in walking) * SHORT STATURE * HEADS APPEAR LARGE - FONTANELLES DELAY CLOSING * BANDY/BOW LEGS when they START WALKING * EPIPHYSES FLARE - KNOBBLY BITS at ENDS of WRISTS, RIBS, LEGS * FAILURE to THRIVE
OSTEOMALACIA:
* BONE PAIN, MUSCLE WEAKNESS (waddling gait + slower, difficult walking), FRAGILE BONES (more prone to #) * PEOPLE WHO AVOID OUTSIDE e.g. work, fears * NO BONY DEFORMITY - PAIN W/I JOINTS, MUSCLE DYSFUNCTION (cannot get out of chairs as weak muscles) * MICRO # RUNNING THROUGH CORTEX - never become full #, pain localised to micro # (ends of long bones, pepperpot skull - loosened areas of skull)
8
Q
Rickets + Osteomalacia: aetiology
A
- SEVERE NUTRITIONAL VITAMIN D/CALCIUM DEFICIENCY causes INSUFFICIENT MINERALISATION causing RICKETS/OSTEOMALACIA
- Vitamin D stimulates absorption of calcium + phosphate from the gut, after which calcium and phosphate become available for bone mineralisation
- SURGERY = GASTRECTOMY, SMALL INTESTINE REMOVAL
- COELIAC DISEASE, MALABSORPTION
- KIDNEY/LIVER DISORDERS
- DRUGS e.g. phenytoin
9
Q
Rickets + Osteomalacia: investigations/diagnosis
A
- BLOODS + URINE = CALCIUM, PHOSPHORUS, VITAMIN D LVLS - 25(OH)VIT D (not active form)
- X-RAYS for MICRO #/#
- DEXA SCAN
10
Q
Rickets + Osteomalacia: management
A
• BENT LEGS can be TREATED if FOUND EARLY ENOUGH - otherwise SURGEON to STRAIGHTEN LEGS
- SUN EXPOSURE
- DIET = ADEQUATE VITAMIN D + CALCIUM
- VITAMIN D SUPPLEMENTS
11
Q
Osteogenesis imperfecta: what is it
A
• GENETIC DISORDER of CONNECTIVE TISSUE - resulting in FRAGILE BONES from MILD TRAUMA (even acts of DAILY LIFE)
12
Q
Osteogenesis imperfecta: presentation
A
- Broad clinical range from those who are PRENATALLY FATAL - those only presenting in 40s w/ EARLY ‘OSTEOPOROSIS’
- DISEASE PHENOTYPE VARIES GREATLY - EVEN W/I FAMILY
- LOW ENERGY #; BONES w/ ALTERED SHAPE
- GROWTH DEFICIENCY
- DEFECTIVE TOOTH FORMATION (DENTIGENESIS IMPERFECTA) - DENTINE FEELS PAIN, COLLAGEN UNDERNEATH ENAMEL
- HEARING LOSS - HEARING TEST REGULARLY
- BLUE SCLERA
- SCOLIOSIS
- BARREL CHEST
- LIGAMENTOUS LAXITY - HYPERMOBILE
- EASY BRUISING
- JOINT/BONE PAIN
13
Q
Osteogenesis imperfecta: aetiology
A
- GENETIC DISORDER of TYPE 1 COLLAGEN (28 diff. types):
- TYPE 1 = MILDER FORM, when CHILD STARTS WALKING, can PRESENT in ADULTS
- TYPE 2 = LETHAL by AGE 1
- TYPE 3 = PROGRESSIVE DEFORMING w/ SEVERE BONE DYSPLASIA + POOR GROWTH
- TYPE 4 = SIMILAR to TYPE 1, but MORE SEVERE
14
Q
Osteogenesis imperfecta: investigations/diagnosis
A
• CLINICAL DIAGNOSIS - FULL MEDICAL Hx + EXAMINATION
- X-RAYS for # + BONE CHANGES
- DEXA
15
Q
Osteogenesis imperfecta: management
A
- SURGICAL = TREAT # e.g. long bones have rods implanted to maintain straightness, spine can develop scoliosis
- MEDICAL = PREVENT # (IV BISPHOSPHONATES - can be given to babies, stopped for a while until # start, then re-started + VITAMIN D SUPPLEMENTS)
- PHYSIOTHERAPY
- SOCIAL = EDUCATIONAL + SOCIAL ADAPTATIONS
- HEARING TEST
- ORTHOTICS
