Biology of Injury and Healing: Clinical Correlations

Question 1

what is the most common mechanism of an ankle sprain?

Answer 1

inversion

Question 2

most commonly strained ligament in the ankle

Answer 2

anterior talofibular ligament and calcaneofibular ligament (to a lesser extent??)

Question 3

acute injury process of injury and healing

Answer 3

bleeding
clot formation
inflammation
repair (fibroblast proliferation and neovascularization)
remodeling

Question 4

types of 5th metatarsal fractures

Answer 4

• avulsion (5th metatarsal base at peroneus brevis insertion)
• jones (traumatic fracture at the metaphyseal-diaphyseal junction
• “pseudo-jones” (stress fracture to proximal diaphyseal
• dancer’s (spiral fracture mid to distal diaphysis)

Question 5

what tendon is oftentimes responsible for an avulsion fracture? (attached to the 5th metatarsal)

Answer 5

fibularis tertius tendon

Question 6

what tests can be performed to test for Maisonneuve (proximal fibula) fractures and high ankle sprains?

Answer 6

external rotation and squeeze tests

side note: with lateral ankle sprains, externally rotating the ankle with NOT bother the patient!

Question 7

in general, what type of tissue heals with least complete recovery? and why?

Answer 7

cartilage (because of poor blood supply)

Question 8

what symptom would make you most suspicious of joint mice (loose bodies)?

Answer 8

locking

Question 9

what is required for ligament healing?

Answer 9

need good blood supply
need damaged section to be approximated or guided to correct area
need relative rest

Question 10

bony healing process

Answer 10

bleeding (seconds-minutes)
clot formation (minutes-hours)
inflammatory stage (hours-days)
repair stage (1-2+ weeks-3+ months): osteoclasts and osteoblasts invade blood clot
remodeling stage (1-2 years)

Question 11

steps of repair stage

Answer 11

• osteoclasts and osteoblasts invade blood clot
• soft callus formation (2-6 weeks)
• hard callus formation (4-12+ weeks)
• callus maturation (12-26 weeks)
• bony gaps bridged (6-12 months)

Question 12

what factor most influences the strength of healed bone?

Answer 12

calcium content of bony repair

Question 13

diaphysis

Answer 13

mid shaft of bone

Question 14

metaphysis

Answer 14

area between shaft and growth plate

Question 15

physis

Answer 15

growth plate

Question 16

epiphyses

Answer 16

end of long bone

Question 17

apophysitis

Answer 17

pain and inflammation of ossification centers from repetitive tension

Question 18

pain pattern of apophysitis

Answer 18

stages:

1. after activity
2. at the beginning of an activity
3. throughout activity
4. all the time

Question 19

treatments of apophysitis

Answer 19

activity as tolerated, stretching, ice with or without NSAIDs

Question 20

complications of apophysitis

Answer 20

bony hypertrophy; fracture (rare)

Question 21

common sites and names of specific apophysitis

Answer 21

• osgood schlatter-tibial tuberosity
• sever’s-calcaneal apopjysitis
• sinding-larsen-johansson-distal patellar pole
• anterior superior iliac spine (ASIS)-sartorious
• anterior inferior iliac spine (AIIS)-rectus femoris
• little leaguer’s elbow-medial epicondyle

Question 22

exam findings for a patient with little leaguer’s elbow

Answer 22

• pain over the UCL
• pain with valgus stress
• pain with milking maneuver
• subtle increased laxity compared to opposite side
• tinel’s test=mild localized tingling sensation
• strength=all within normal limits

Question 23

ACL graft healing timeline

Answer 23

• ligamentization-revascularization with vascular synovial layer
• allographs
  
  • starts at 4-6 weeks
  • complete revascularization ~20 weeks
  • fixation weakest link until healed
  • remodeling 1 year~~histological and biochemical properties of native ACL
• autographs
  
  • patellar tendon-graft remodeling 4-8 weeks
  • hamstring by 12 weeks