Tissue Healing - Repair/Regeneration

Question 1

Type 1 Pneumocytes

Answer 1

Help with gas exchange

Question 2

Type 2 Pneumocytes

Answer 2

Secrete Surfactant

Question 3

Repair vs Regeneration - Lungs

Answer 3

Type 2 Pneumocytes are able to act similar to stem cells by coming back to injured cells as type 2 and type 1.

Question 4

Pneumonia vs Asbestosis
Regeneration or Repair?

Answer 4

Viral Pneumonia: Regeneration due to cell loss but maintenance of extracellular matrix

Asbestosis: Repair due to cell loss and destruction of extracellular matrix - Restrictive lung disease

Question 5

Heart
Regeneration or Repair?

Answer 5

• Only Repair; Heart cells cannot divide
• Takes 8 to 12 weeks to form a dense connective tissue (scar) after Myocardial Infarction (Heart Attack)

Question 6

CNS - Neurons

Answer 6

• Repair Only
• Collagen forms in the area of injury (Glial Cells)

Question 7

PNS - Neurons

Answer 7

• Repair Only
• Scar tissue repair
• Gap <3 mm - reinnervation

Question 8

Skeletal Muscle

Answer 8

• Stable Cell
• Regeneration can occur if sarcolemma sheaths (basement membane) is intact
• If destroyed repaired

Question 9

Stages of Muscle
Regeneration or Repair?

Answer 9

Stage 1: Regeneration
Stage 2: Repair
Stage 3: Repair

*Repair in muscular dystrophy (lethal injury), trauma, motor vechile accident, knife wound

Question 10

Tendon and Ligament - Background

Answer 10

• Stable Cells
• Type 1 Collagen
• Sustain unidirectional tensile loads and compressive forces
• Small vascular supply
• Hard to treat; healing is 8-12 weeks up to couple of years

Question 11

Tendon and Ligament Injury

Answer 11

• 40 to 50 weeks to regain normal strength after surgery
• Tensile strengt is 40-60% of healthy tendon
• Injurt risk is higher with rapid and oblique forces, degenration, and chronic overload

Question 12

Tendinitis

Answer 12

Inflammation of tendon

Question 13

Tendinosis

Answer 13

Degeneration with little or no inflammation

Question 14

Tendons
Regeneration or Repair

Answer 14

Ask Steni

Question 15

Stable Cell

Answer 15

Cells that multiple only when needed

Question 16

Ligaments

Answer 16

• MCL injuried heal better than ACL
• Extraarticular ligament (MCL): same healing as other tissues
• Intraarticular ligament (ACL): Matric metalloproteinases are highly active and in large acmounts that affects clotting and hemoatoma formation

PT Implications
- Early mobilization is good
- Too little or too aggresive loads - joint laxity
- NSAIDS - prostaglandins (within first two weeks)

Question 17

Articular Cartilage

Answer 17

• Does not regenerate after adolescence: Healing occurs by fibrous scar tissue or no healing at all
• Treatment: Microfracturing

Question 18

Bone Healing and Repair

Answer 18

-Stable cells
Osteoclast, osteoblast, osteocyte
Regeneration (no scar formation)

Question 19

Bone Healing and Repair

Answer 19

-Stable cells
Osteoclast, osteoblast, osteocyte
Regeneration (no scar formation)

Question 20

Bone Healing and Repair Phases

Answer 20

1). Inflammatory
2). Reparative (Collagen type 3 - soft callus); Don’t put too much pressure
3). Remodeling (Collagen type 1 - hard callus); Can withstand external forces

Question 21

Phyical Therapy Treatment - Bone

Answer 21

-Immobilization (4-8 weeks)
- Weight bearing restricitons: No WB, TTWB, PWB, FWB
- Progressive loading is beneficial, but too little or too aggressive load is not recommended
- Remember the strength of the healing bone is not the same as its original
- Complications: Non-union, Malunion, Delayed union

Question 22

Malunion

Answer 22

Healing in a less than optimal position

Question 23

Delayed Union

Answer 23

Healing not happeneing as fast as it should

Question 24

Non-Union

Answer 24

Fail to heal

Question 25

What are the 4 examples of stable cells?

Answer 25

• Muscle
• Bone
• Ligament
• Tendon