Nerve and Tendon Injuries Flashcards

1
Q

What is a sesamoid bone?

Give a common example

A

In anatomy, a sesamoid bone is a bone embedded within a tendon or a muscle

Patella

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2
Q

What fibres attach tendons to bone?

A

Sharpey’s fibres

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3
Q

What are tenocytes?

A

Elongated fibroblast type cells. The cytoplasm is stretched between the collagen fibres of the tendon. They have a central cell nucleus with a prominent nucleolus. Tendon cells have a well-developed rough endoplasmic reticulum and they are responsible for synthesis and turnover of tendon fibres and ground substance.

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4
Q

What type of collagen makes up the structure of tendons along with tenocytes?

A

Type 1

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5
Q

Collagen bondles arrange into fascicles which arange into tendon.

What covers these three structures?

A

Collagen bundles covered by endotenon

Fascicles covered by paratenon

Tendon covered by epitenon

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6
Q

What is a vinculum?

A

a connecting band of tissue, such as that attaching a flexor tendon to the bone of a finger or toe

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7
Q

Fine network of blood vessels exist in which covering of tendon structure?

A

Paratenon

covers fascicles

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8
Q

Immobility reduces what in joints?

A

Water content and glycosaminoglycan concentration and strength

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9
Q

What can cause tendon degeneration over time as we age?

A

Intrasubstance mucoid degeneration

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10
Q

What are the signs and symptoms of tendon degeneration?

A

May be swollen
Painful
Tender
May be asymptomatic

?Precursor to rupture

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11
Q

Give an example of tendon inflammation

A

de Quervain’s stenosing tenovaginitis

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12
Q

What is de Quervain’s stenosing tenovaginitis?

What causes it, What is its presentation, What test can you perform?

A

Tendons of EPB and APL passing through common tendon sheath at radial aspect of wrist

Swollen, tender, hot and red

Positive Finkelstein’s test

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13
Q

What is Finkelstein’s test?

A

To perform the test, the examining physician or therapist grasps the thumb and ulnar deviates the hand sharply, as shown in the image. If sharp pain occurs along the distal radius, de Quervain’s tenosynovitis is likely

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14
Q

What is Eichhoff’s test?

Why is Finkelstein’s test used more?

A

Ask patients to flex their thumb and clench their fist over the thumb before ulnar deviation, but with ulnar deviation performed by the practitioner.

Eichhoff’s test is commonly confused with Finkelstein’s test. However the Eichhoff’s test may produce false positive results, while a Finkelstein’s test performed by a skilled practitioner is unlikely to produce a false positive

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15
Q

Where does enthesiopathy give pain?

Give a common example

A

More usually at muscle origin rather than tendon insertion

Lateral humeral epicondylitis (tennis elbow)
-Common extensor origin

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16
Q

Give a common example of traction apophysitis

A

Osgood Schlatter’s disease

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17
Q

What is Osgood Schlatter’s disease?

What is it characterised by?

What are the risk factors?

A

Osgood–Schlatter disease aka apophysitis of the tibial tubercle, is an inflammation of the patellar ligament at the tibial tuberosity.

It is characterized by a painful bump just below the knee and is most often seen in young adolescents.

Risk factors include overuse (especially in sports involving running, jumping and quick changes of direction) and adolescent growth spurts.

18
Q

What is Sever’s disease?

How does it present?

A

Traction apophysitis at insertion of TA into os calcis
(inflammation of the growth plate in the heel of growing children, typically adolescents)

The condition presents as pain in the heel and is caused by repetitive stress to the heel and is thus particularly common in active children.

It usually resolves when the bone has completed growth or activity is lessened.

19
Q

What is an apophysis?

A

The apophysis is a normal bony outgrowth that arises from a separate ossification centre and fuses with the bone in course of time. The apophysis is a site of tendon or ligament attachment, as compared to the epiphysis which contributes to a joint.

20
Q

What is an avulsion fracture?

A

An avulsion fracture is an injury to the bone in a location where a tendon or ligament attaches to the bone. When an avulsion fracture occurs, the tendon or ligament pulls off a piece of the bone.

21
Q

Give a common example of avulsion fracture

What is it, What does the effected area look like?

A

Insertion of extensor tendon into dorsum of base of distal phalanx of finger

Forced flexion of extended finger

22
Q

How do you treat mallet finger?

A

Mallet splint

-Immobilises so it can heal

23
Q

How can you examine an achilles tendon rupture?

A

“Positive” Simmonds (squeeze) test
-Get them to kneel on chair and squeeze calf -> if foot plantar flexes then tendon ok

Palpable tender gap

24
Q

What is the mechanism of rupture in achilles tendon tear?

A

Pushing off with weightbearing 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 plantarflexed foot (10%)
-e.g. fall from height

25
Q

What is the classic situation for an achilles tendon tear?

A

Raquet sport

Accuse person behind of hitting or kicking

26
Q

What is the epidaemiology of achilles tendon rupture?

A

Males 2:1 females

Peak age 30-40y, rises again >60y

Incidence rising (up 30-40% since 1980)

27
Q

How do you treat achilled tendon rupture?

A

Conservative

  • PoP cast for 10 wks
  • —Higher risk of re-rupture

Operative

  • With open repair and earlier mobilisation
  • –For younger active patients
  • –Risk of wound problems
  • –Re-rupture rate lower but still occurs
28
Q

What is Tennis leg (aka plantaris syndrome)?

A

Tear of medial head of gastrocnemius at musculotendinous junction with achilles tendon

29
Q

Describe the healing process of tendons

What initiates it? What phases? how strong?

A

Tendon healing initiated by fibroblasts (from epitenon) and macrophages

3 phases:

  • Inflammatory
  • Fibroblastic (collagen producing)
  • Remodelling

Tendon repairs are wekest at 7-10 days; regain most of original strength by 3-4 weeks and achieve maximum strength in 6 months

30
Q

How are axons arranged to form nerves?

What covers these 3 structures?

A

Axons are coated with endoneurium and grouped into,

Fascicles (nerve bundles) covered with perineurium, these are arranged to form the,

Nerve which is covered with epineurium

31
Q

Describe the 3 types of nerve fibres

Diameter, myelination, speed, and an example of what it does

A

Type A:

  • Diatemeter = 10-20um
  • Myelination = heavy
  • Speed = fast
  • Example = touch

Type B:
-Diameter =

32
Q

What is neurapraxia?

A

Neurapraxia is a disorder of the peripheral nervous system in which there is a temporary loss of motor and sensory function due to blockage of nerve conduction, usually lasting an average of six to eight weeks before full recovery

33
Q

Describe the pathophysiology of neurapraxia

A

This condition is typically caused by a blunt neural injury due to external blows or shock-like injuries to muscle fibers and skeletal nerve fibers, which leads to repeated or prolonged pressure buildup on the nerve. As a result of this pressure, ischemia occurs, a neural lesion results, and the human body naturally responds with edema extending in all directions from the source of the pressure. This lesion causes a complete or partial action potential conduction block over a segment of a nerve fiber and thus a reduction or loss of function in parts of the neural connection downstream from the lesion, leading to muscle weakness.

Neurapraxia results in temporary damage to the myelin sheath but leaves the nerve intact and is an impermanent condition; thus, Wallerian degeneration does not occur in neurapraxia

34
Q

What is axonotmesis?

A

Axonotmesis is a disruption of nerve cell axon, with Wallerian degeneration occurring below and slightly proximal to the site of injury. If axons and their myelin sheath are damaged, but Schwann cells, the endoneurium, perineurium and epineurium remain intact, it is called axonotmesis. Axonotmesis is usually the result of a more severe crush or contusion than neuropraxia

35
Q

What is neurotmesis?

A

Neurotmesis (in Greek tmesis signifies “to cut”) is part of Seddon’s classification scheme used to classify nerve damage. It is the most serious nerve injury in the scheme. In this type of injury, both the nerve and the nerve sheath are disrupted. While partial recovery may occur, complete recovery is impossible.

36
Q

What is morton’s neuroma?

A

Morton’s neuroma is a benign neuroma of an intermetatarsal plantar nerve, most commonly of the second and third intermetatarsal spaces (between 2nd−3rd and 3rd−4th metatarsal heads), which results in the entrapment of the affected nerve.

The main symptoms are shooting pain and/or numbness, sometimes relieved by removing footwear.

37
Q

What is the first sensory modality to return after nerve injury?

A

Pain

38
Q

How slow is regeneration of nerves?

A

1mm/day

39
Q

Proximal axonal budding occurs after how long?

A

1 month delay

40
Q

What simple examination test can you use to assess healing of nerve injury of hand?

A

Tinel’s sign

paraesthesiae will be felt as far distally as regeneration has progressed