Medical Biotechnology Master’s Programmes
at the University of Pécs and at the University of Debrecen
Identification number: TÁMOP-4.1.2-08/1/A-2009-0011
DISORDERS AND DISEASES OF
LOCOMOTOR ORGANS PART 1
Gyula Bakó and Erika Pétervári
Molecular and Clinical Basics of Gerontology – Lecture 6
Medical Biotechnology Master’s Programmes
at the University of Pécs and at the University of Debrecen
Identification number: TÁMOP-4.1.2-08/1/A-2009-0011
Outline
• Changes of the musculoskeletal system in the elderly
• Common diseases of locomotor organs in the elderly – causes of falls, chronic immobilization and disability
• Immobilization and remobilization in the
elderly
Incompetence (Confusion)
Geriatric Giants
Immobility
(Falls) Incontinence
Iatrogenic disorders Impaired
homeostasis
Factors adversely affecting
locomotor organs in the elderly
Organ damage
•
Pain, rigidity of joints and muscles•
Impaired renal function•
Associated chronic diseases•
Multiple medications ,higher risk for side effects
•
Impaired fluid and food intake•
Failing memory,deterioration of cognitive function
Functional disorders
•
Gait disturbances•
Impaired self-reliance•
Impaired ability to carry out household duties•
Limited leisure activities Social difficulties•
Financial problems•
Inappropriate housing•
Death of spouse/caretaker•
Social isolation (scattered family)Changes of the musculoskeletal system in the elderly
I Changes and dysfunction of the skeletal muscles in the elderly
II Aging-associated changes in the joints
III Aging-associated changes in the bones
I: Changes of the skeletal muscles:
sarcopenia in the elderly
Body weight decreases between 30-75 years of age, mainly due to a progressive decrease in the number and size of muscle fibers and that of muscle mass.
Causes:
• reduced physical activity
• changes in CNS and peripheral nervous system within which a decreased number of active motor units are found
• decrease in protein synthesis in skeletal muscle fibers
• reduced protein intake in the elderly
• relative scarcity of anabolic hormones (GH, IGF-I, testosterone, DHEA)
Pathogenesis of skeletal muscle dysfunction in the elderly
I Neurological causes
(pronounced in peripheral neuropathies)
• Reduced number and size of motor neurons in the spinal cord
• Decrease in the axonal conductivity
• Decrease in the neuromuscular transmission - number of neuromuscular end plates
- number of acetylcholine receptors
- release of neurotransmitters
Pathogenesis of skeletal muscle dysfunction in the elderly
II Primary muscle damage
• Injury induced by contractures
• Altered signal transduction in the muscle
(impaired effects of trophic factors, hormone resistance)
• Reduced number of type II muscle fibers
Age (years)
Muscle mass
Adipose
tissue Bone
25 30% 20% 10%
75 15% 40% 8%
Age-related changes in body composition: muscle loss
Loss of type II muscle fibers
• About 50% of the muscle mass is lost by the time we develop sarcopenia due to old age. It affects mostly type II (fast twitch) muscle fibers in contrast to type I (slow twitch) muscle fibers.
• Type II muscle fibers are responsible for fast, intensive contractions, while type I fibers are responsible for slow, long lasting movements.
• Due to the loss of muscle fibers with age, 20% of the maximal isometric contraction force is lost by the
age of 60. By the age of 75 the loss is about 50%.
Pathogenesis of skeletal muscle dysfunction in the elderly (cont.)
III Combined neuromuscular mechanisms
• Disorders of the electric discharge of muscle fibers
• The stimulus- contraction process is disrupted
IV Common abnormal biochemical processes affecting the muscle
• oxidative stress
• mutation in the mitochondrial DNA
• vasculopathies developing with age
II: Aging-associated changes in the joints
Cartilage coating the bone endings contains chondrocytes, which produce collagen fibers, hyaluronic acid and
proteoglycans building a high water-containing, elastic substance.
The proteoglycans attached to hyaluronic acid and
aggregated within the collagen network are saturated with
water and thus provide the cartilage with the capacity to resist compression and to re-expand after compression.
In the elderly, the amount and water content of the cartilage mass decrease, its resistance against mechanical impacts is less effective.
Impacts from every direction destroy the joints as the ligaments become more rigid. (Overweight.)
Aging of the joints arthrosis
• water binding of hyaluronic acid
• changed composition (not the amount) of proteoglycans
Reduced water content (in arthrosis it increases) and amount of cartilage mass lead to less resilient
cartilage.
Without the protective effects of the proteoglycans, the collagen fibers of the cartilage become
susceptible to degradation.
• Decreased viscosity of the synovial fluid.
Aging in soft tissues
• Impairment of collagene synthesis, that of post- translational
modification of collagene
• Alterations in the
quantity and quality of intercellular matrix
(menisci, intervertebral discs)
• Deposition of calcium crystals in connective tissue
Mechanical
resistance of soft tissues are
decreased
III: Aging-associated changes in the bones
Bone mass decreases from the age of 55 by around 1%/year in men and by 3-4%/year in women (peak bone mass is reached at 25-35 years of age, its value is higher in men).
During the course of aging metabolic activity of osteoblasts is decreasing.
Causes of deterioration of bone mass:
inactivity, vitamin D deficiency; hormones: estrogen, progesterone, calcitonin, parathormone (secondary hyperparathyroidism), cortisol; alcohol; smoking.
Consequences:
osteopenia, osteoporosis, fractures.
Common diseases of locomotor organs in the elderly
• Osteoarthrosis, the most common disease of locomotor organs of people over 50
• Rheumatoid arthritis
• Gout
• CPPD arthritis (pseudo-gout)
• Osteoporosis
Osteoarthrosis (OA)
degenerative joint disease
Definition:
Each element of the joint becomes gradually and
progressively injured causing swelling, pain, stiffness and functional loss.
A degenerative process leads to incongruence of the articular cartilage surfaces, inflammation of the joint capsule (synovitis), muscle atrophy and a crackling noise (called “crepitus”) when the affected joint is moved.
It commonly affects the large weight bearing joints
(hips, knees).
Osteoarthrosis (OA)
focal degeneration of the joints
Calcification of lax tendons
(ligaments)
New bone outgrowths:
• beneath the lesion (subchondral)
• at the edge, called “spurs” or osteophytes narrowing of the joint space
Thickened bone
Loss of cartilage Cartilage particles
“Spurs” or osteophytes
Osteoarthrosis (OA)
degenerative joint disease
Prevalence:
It affects 30% of the adult population. 90% of people over 60 have radiological signs of arthrosis.
Incidence:
88 (hip joints), 20 (knee), and 300 (hand)/100,000/year
Significance:
It is the most common cause of disablement and
NSAIDs’ (non-steroidal anti-inflammatory drugs)
prescriptions.
OA a multifactorial degenerative joint disease
Causes:
Basic causes:
• bipedalism (erect posture and work), increased burden on the joints at the knees
• extended life span
Risk factors for faster progression:
• Mechanical causes: obesity, congenital disorders, macro- and microtrauma, overuse, previous inflammation of the joints and bone necrosis.
• Metabolic causes: defects in collagen synthesis, diabetes, hyperthyroidism, hypothyroidism, hyperparathyroidism,
hemochromatosis, acromegaly, ochronosis, etc.
Clinical signs of OA
• Usually above 40 years of age
• Moderate pain in one or more joints
• Pain at initiation of movement
• In the beginning, the pain ameliorates at rest, later it is aggravated by rest
• Morning stiffness < 30 minutes
• Impaired function: instability, diminished movements , decrease in muscle strength
• Crepitation, crackling noise
• Swelling, deformity
• Abnormal alteration of the axis
• Lack of systemic symptoms
Therapeutic measures
Pharmacological treatment
• Pain killers/analgetics
• NSAID
• Intra-articular steroids Psycho-social treatment
• Patient education
• Improvement of life-style and diet
• Psychological support
• Patient clubs
Weight reduction
Consultations with patients Orthoses
(amputee knee shell, knee brace, orthotic heel support, arch support )
Other treatments
• Physiotherapy
• Surgical intervention