Growth Injury and Repair - Tendon Injuries

Question 1

What are sharpeys fibres?

Answer 1

Sharpey’s fibres (bone fibres, or perforating fibres) are a matrix of connective tissue consisting of bundles of strong predominantly type 1 collagen fibres connecting periosteum to bone.

Sharpey’s fibres are also used to attach muscle to the periosteum of bone by merging with the fibrous periosteum and underlying bone as well. A good example is the attachment of the rotator cuff muscles to the blade of the scapula.

Question 2

What is the structure of tendons?

Answer 2

They have a longitudinal arrangement of cells (mostly tenocytes) and fibres (collagen type 1 triple helix).

Question 3

What are tenocytes?

Answer 3

Tenocytes are cells that are fibroblast like and form tenodons.

They synthesise extracellular matrix including assembly of early collagen fibres which are the basic units of a tendon.

Question 4

What are the substructures of tendons and what are they covered by?

Answer 4

COLLAGEN BUNDLES covered by endotenon,

FASCICLES covered by paratenon,

TENDON covered by epitenon

Question 5

Where is the blood supply for tendons?

Answer 5

Fine network of blood vessels in the paratendon

Question 6

Give an example of where you might find a tendon sheath?

Answer 6

Flexor tendons in distal palm and fingers

Question 7

How are tendons connected to the tendon sheath in distal palm and fingers?

Answer 7

By the vincula

Question 8

What is the structure of tendon sheaths?

Answer 8

Tendon sheaths are tubular double-layered sacs lined with synovial membrane and containing synovial fluid. Tendon sheaths enclose many tendons, including the flexor tendons of the wrist and ankle where they perform the important function of keeping friction as low as possible, while faciliating movement of the joint.

Question 9

What is the function of tendons?

Answer 9

They are flexible and are very strong in tension

Question 10

What happens when tendons become immobile?

Answer 10

This reduces the water content and glycosaminoglycan concentration and strength

Question 11

What are the types of tenon injury?

Answer 11

• degeneration
• inflammation
• enthesopathy - disorder involving the attachment of a tendon or a ligament to bone.
• traction apophysitis (osgood schlatters disease)
• avulsion (pulling or tearing away) ± bone fragment *
• tear - intrasubstance (rupture) *
• tear - musculotendinous junction
• laceration/ incision
• crush / ischaemia / attrition
• nodules

Question 12

Give an example of a degeneration disease of a tendon

Answer 12

Achilles tendon

Intrasubstance mucoid degeneration (cell substance is covnerted into glutinus substance like mucus)

Question 13

What are the signs and symptoms of achilles intrasubstance mucoid degeneration?

Answer 13

May be swollen, painful, tender and may be asymptomatic

Question 14

Give an example of a disease causing inflammation of a tendon

Answer 14

De quervain’s stenosing tenovangitis

or

Enthesiopathy (an example of a ligament would be plantar fasciitis)

Question 15

What tendons are involved in De quervain’s stenosing tenovangitis?

Answer 15

Extensor pollicis brevis and abductor pollicis longus

They pass through the common tendon sheath at radial aspect of wrist.

Question 16

What are the signs and symptoms of de quervains stenosing tenovangitis?

Answer 16

Swollen, tender, hot, red

Positive finklestein’s tets

Question 17

Which part of the muscle is usually affected in enthesiopathy?

Answer 17

Usually the muscle insertion as opposed to the muscle origin

Question 18

What is the difference between origin and insertion?

Answer 18

Origin - fixed attachment

Insertion - moves with contraction

Question 19

Which parts of the knee are affected in traction apophysitis? (osgood schlatters disease)

Answer 19

insertion of patellar tendon into anterior tibial tuberosity

adolescent active boys

Recurrent load

Inflammation

There is pulling on the insertion, but it does not cause any harm.

Question 20

Define apophysitis

Answer 20

It is the painful inflammation of a bony outgrowth, especially in the area of active growth such as the end of a long bone.

Question 21

Define avulsion

Answer 21

Pulling or tearing away

Question 22

Which part of the muscle is affected in avulsion?

Answer 22

Insertion

Question 23

What causes avulsion?

Answer 23

•Load exceeding failure strength while muscle contracting

Question 24

What is the treatment for avulsion?

Answer 24

•Conservative - stack splint

–Limited application

–Retraction tendon

•Operative

–Reattachment tendon

•Through bone

–Fixation bone fragment

Question 25

How does an intrasubstance rupture happen? e.g achilles

Answer 25

Load exceeds failure strength

Question 26

What is the mechanism of rupture of an achilles tendon?

Answer 26

·pushing off with weight bearing forefoot whilst extending knee joint (53%) e.g. sprint starts or jumping movements

·unexpected dorsiflexion of ankle (17%) e.g. slipping into hole

·violent dorsiflexion of plantar flexed foot (10%) e.g. fall from height

Question 27

What are the achilles tendon rupture tests?

Answer 27

Simmonds test - squeeze test

Altered angle of dangle

Palpable tender gap

Question 28

Where is it common to have a musclotendinous tear?

Answer 28

•- e.g. medial head of gastrocnemius at musculotendinous junction with Achilles tendon

–“plantaris syndrome” (mis-called)

–often partial

Question 29

What is the treatment for a tendon rupture?

Answer 29

•Conservative

–Where ends can be opposed

• Mobilise (partial rupture) e.g. med lig knee
• Splint/cast

–Where healing will occur

• Not intraarticular
• Operative

–High risk rerupture

–High Activity

–Ends cannot be opposed

Question 30

Where is incision likely to occur to tendons?

Answer 30

•- e.g. esp. finger flexors (FDS & FDP) (flexor digitorum superficialis and felxor digitorum profundus)

–common

–males > females

–young adults

–repair surgically & early - beware old injuries!

–“technically challenging”!