5. Examination of the tendons and tendon sheaths Flashcards
What is a tendon?
A fibrous connective tissue that connects muscle to bone
Function of tendon:
Moves the joint
What is a tendon sheath?
Structure that surrounds the tendon, helps and protects tendons from abrasive damage as they move
Name the tendon sheaths:
- DFTS = Digital Flexor Tendon Sheath
- Carpal sheath
- Tarsal sheath
- Tendon sheath of extensor tendons (dorsal surface)
- Radius
- Carpus
- 5th metacarpal
- 3rd metacarpal
- 1st phalanx
- 2nd phalanx
- 3rd phalanx
- Distal sesamoid
- Proximal sesamoid
- Extensor branch of suspensory ligament
- Deep digital flexor tendon
- Stright sesamoid ligament
- Oblique sesamoid ligament
- Suspensory ligament
- Superficial digital flexor tendon
- Check ligament of deep digital flexor tendon
- Check ligament of superficial digital flexor tendon
- Digital cushion
- Frog
- Sole
- Hoof wall
- Heel
Most important clinical structures of tendons and tendon sheaht:
- SDFT = Superficial Digital Flexor Tendon
- DDFT = Deep Digital Flexor Tendon
- Suspensory ligament
- DFTS = Digital Flexor Tendon Sheath
Which strucutre is damaged?
Peroneus tertius rupture. A concurrent flexion and extension of hock and stifle
Part of reciprocal appartatus of the hindlimb.
Pathognomonic clinical signs of peroneus tertius rupture:
horse are able to extend the hock while the stifle
is flexed
horses are able to bear weight on the limb
characteristic dimple on the caudodistal aspect
of the soft tissue of the crus
at trot: overextension of the hock, lameness, delayed protraction of the affected limb
SDFT - Origin and insertion
Origin: Epicondylus medialis humeri
Insertion: Proximopalmar on phalanx media
Injuries of SDTF:
Common in forelimb - Mid-metacarpal region in racehorses and events due to traumatic overreach
Name a strucutre/band of the SDFT, which wraps the DDFT:
Manica flexoria
Found just proximal of the fetlock region
Which structure is damaged?
DDFT rupture
DDFT - Origin and insertion
Origin:
Insertion: Facies flexoria of distal phalanx
Injuries of DDFT:
- In pastern region
- In fetlock region: Typical in high level show eventers
- Complete rupture: Toe flips up
-> Generally poor prognosis
What is the suspensory ligament?
A structure which stabilize the normal hyperextension of the fetlock joint and provide excessive hyperextension.
The ligament run down on palmar/plantar aspect of the cannon bone, btw the splint bones
Suspensory ligament - origin and insertion:
Origin: Just below carpus/tarsus
Insertion: With two branches, one of each dorsal site of pastern bone
predilection sites of Injuries of suspensory ligament:
proximal origin and at the distal branches
Typical injuries of the suspensory ligament:
- complete rupture: fetlock drops, severe hyperextension, poor prognosis
- in forelimb: prox. susp. desmitis
- in hindlimb: prox. susp. desmopathy: often bilateral in dressage horses (more motion in hind limb), predisposing factor: straight hock
- injury of the distal branches: distension of MCP / MTP joint, thickening, response to flexion
Which structure is damaged?
Complete rupture of the suspensory ligament
Which structure is damaged?
Complete rupture of the suspensory ligament
DFTS - Origin and insertion
Origin: Distal 1/3 of MC/MT
Insertion: just proximally to the navicular bursa
Which structures is sorrounded by DFTS?
SDFT and DDFT
Disorders of DFTS?
- non-septic tenosynovitis: common in sports medicine practice
- septic tenosynovitis: in case of wounds, penetrating injuries
- manica flexoria tears
- distension
->bilateral: often cosmetic problem
->unilateral with clearly delineated swelling: more likely to implicated in lameness
What can be seen?
Palmar annular ligament syndrome.
Distension of tendon sheath and swelling
What is the palmar annular ligament syndrome?
Distension of DFTS and thickening of palmar annular ligament
What can palmar annular ligament syndrome cause?
Desmopathy of PAL, which again causes external trauma and overextension of the fetlock
Consequences of palmar annular ligament syndrome?
Chronic inflammation, causing adhesions and fibrosis
If the palmar annular ligament syndrome keeps getting worse?
We call it “perpetuating condition”.
We see inflammation, pressure, stenosis - which will induce further inflammation
Examination of a horse with tendon or tendon sheath problems:
- history
- clinical examination
-> Observation: visible signs, distension of tendon sheaths (bilateral vs. unilateral)
-> palpation: heat, swelling, pain
-> response to flexion - gait assessment -> grade of lameness
- diagnostic analgesia -> localize the lameness
- ultrasonography
- Tendonography
- standing MRI
Diagnostic analgesia of DDFT:
Distal 4-point block: Affects them distal of fetlock joint
High palmar block: Distal limb including fetlock
Subcarpal block: Whole MC region
Diagnostic analgesia of SDFT:
Distal 4-point block: Affects them distal of fetlock joint
High palmar block: Distal limb including fetlock
Subcarpal block: Whole MC region
Diagnostic analgesia of suspensory ligament:
Lateral palmar analgesia
Suspensory ligament origin infiltration
Diagnostic analgesia of DFTS:
Greater improvement to low 4-point block, than to intrathecal analgesia
What is intratechal anaesthesia?
Lateral or medial approach, 10-15 ml with botj injections
Proximal palmar approach +
Distal palmar approach
What can be check on US?
fibre pattern of SDFT, DDFT
Thickening of PAL
Integrity of the manica flexoria
Can permit detection of tears of the Manica flexoria
What is tendonography?
Radiography of the tendons with usage of contrast material
What technique would you use to perform tendonography?
o patient preparation, aseptic preparation of the skin
o inject 5 - 7 ml meglumine diatrozoate
o than LM view
Diagnostic criteria of tendonography:
o Manica flexoria: outlines as two parallel lines
o tears in DDFT: contrast material in the tendon
what can we evaluate with standing MRI?
Evaluation of bony and soft tissue strucutres
Indication of standing MRI?
If lameness cannot be explained by findings of conventional diagnostic imaging
What is MRI?
Thin slices of 3D
How long time for doing an MRI?
Its VERY time consuming, can be 3-4 hrs for only two feet, and only a small area can be examined.
