bone mineral density and fracture. the plot thickens: the bones thin
TRANSCRIPT
Bone Mineral Density and Fracture
The Plot Thickens: The Bones Thin
New Use(s)?
• Thigh bone connected to the blood stream
• Flexibility, strength and balance
• Custom models
Both Ends against the Middle
• Argument for Impact:
Mechanical stress activates osteocytes
• Argument against Impact:
Trauma initiates chondral degeneration
Osteoporosis and Osteoarthritis
• Osteoarthritis– Mechanoreceptors: Impact a must.Impact a must.
• Osteoporosis– Chondral Damage: No Impact.No Impact.
Osteoporosis vs Osteoarthritis
• Osteoarthritis– Mechanoreceptors: Impact a must.Impact a must.
• Osteoporosis– Chondral Damage: No Impact.No Impact.
Osteoporosis and Osteoarthritis
• Bone arises from cartilage:
Cartilage Bone Both
A Sliver Lining
Chondroblasts and ‘Clasts
Chondrocytes are Family Practitioners
Dynamic Support System
Feedback system
• Architectonic reflects lines of stress
• Buildup of bone reduces deformation
• Osteoporosis should increase response
Competitive Physiology
“Static loading does not prevent osteoporosis”
• Rubin, CT, Lanyon, LE, Baust, G: “Modulation of bone loss during calcium insufficiency by controlled dynamc
load.” Calcif Tis Int 1986;38:209-216.
Turkey wings lead the wayCompetitive Physiology
“Static loading does not prevent osteoporosis”
“Short periods of dynamic loading protect the bones in calcium-deficiency.”
• Rubin, CT, Lanyon, LE, Baust, G: “Modulation of bone loss during calcium insufficiency by controlled dynamc load.”
Calcif Tis Int 1986;38:209-216.
Turkey wings lead the way
• 3H uridine rises six-fold after loading1
• 8 seconds of loading = prevention2
• 72 seconds of loading > 30% - 40%2
• Nothing more with 720 or 3600 seconds2
• 1. Pead, MJ, Suswillo, R, Skerry, TM et al: “Increased 3H uridine levels in osteocytes following a single short period of dynamic bone loading in vivo.” Calcif Tisue Int 1988;43:93-97.
• 2. Rubin, CT, Lanyon, LE: “Regulation of bone formation by applied dynamic loads. J Bone Joint Surg 1984;66A:397-402.
Turkey wings lead the way
Eccentric pulls on periostium increase bone strength, reversing osteoporosis
Lanyon, L.E. “Osteoporosis and exercise.” Topics in Geriatric Rehabilitation. March 1989 4:(2)pp.12- 24.
Woolf, J: The Law of Bone Transformation. Berlin, A. Hirschwald, 1892.
Deforming force