equine carpus anatomy
TRANSCRIPT
Carpal Anatomy
Radiology Rounds
December 15th, 2014
Anatomy
• 3 joints
– Antebrachiocarpal joint
– Middle carpal joint
– Carpomatacarpal joint
• MCJ and CMCJ always communicate
• Palmar outpauching of CMCJ extends distal
– Inadvertent anesthesia of joint when blocking prox metacarpal joint
Anatomy
• Diffusion of mepivacaine between:
– ABCJ and MCJ occurred in 84% of limbs
– MCJ and ABCJ occurred in 96% of limbs (Gough MR et al. EVJ 2002)
• Consider evaluation of whole region
– Carpus
– Carpal canal
– Proximal metacarpus
Anatomy
• Bones
– Radius
– Proximal row
• RCB, ICB, UCB, ACB
– Distal row
• IICB, IIICB, IVCB, occasionally ICB and rarely VCB
– Metacarpal
• IIMCB, IIIMCB, IVMCB
Anatomy
• Soft-tissues:
– Intercarpal ligaments
– Collateral ligaments
– Fibrous joint capsule
– Palmar carpal ligament
Anatomy
• Dorsal:
– Extensor carpi radialis (sheath)
• Dorsolateral:
– Common digital extensor tendon (sheath)
• Extensor retinaculum – distal radius at physealscar
– stabilize ECR and CDET
Tendon sheaths
j Flex carpi radialis (resected)k Ext carpi radialism CDE (humeral head)n CDE (radial head)o DDFp Lat dig flexorq Ulnaris lateralisr Flexor carpi ulnaris (resected)s Ext carpi obliquus
All tendons passing over carpus have sheath, except:• Short tendon of Ulnaris
lateralis• Flexor carpi ulnaris
Dorsal aspect
1 Radius
2 ECRT
3 Long dig abductor T
4 CDET
5 Extensor retinaculum
7 Lat digital extensor T
L
Dorsal aspect
1 Radius
2 Groove for the Long dig adbuctor T.
3 Groove for the ECRT
4 Groove CDET
6 MCL
7 RCB
8 /10/17 Dorsal intercarpal ligament
9 ICB
11 UCB
12 LCL
14 IIICB
15 IVCB
16 Dorsal metacarpal ligamentL
Palmar aspect (no ACB)
Plantar intercarpal ligaments
1-2 RCB and Radius
3 ICB and Radius
4 Stump of ligament connecting ICB and ACB
5 RCB and IICB (med palmar intercarpallig)
6 IICB and IIIMB
7 IIICB and IIIMB
8 Ulnar and III and IVCB (lateral palmar intercarapal lig)
9 Short MCL
Palmar aspect (retinaculum has been removed)
1 Extensor carpi ulnaris T
2 Flex dig profundus T
3 Flex carpi ulnaris T
4 Flex carpi radialis T
5 Ext dig lateralis T
6 Ext carpi ulnaris to the ACB
7 Ext carpi ulnaris
10 Flex dig superficialis T
ACB
L
IV
II
Lateral aspect
1 Extensor carpi radialis T
3 CDET
4 Ext dig lateralis T
5 DDF muscle (humeral head)
6 Ext carpi ulnaris (M. ulnaris lateralis)
to the ACB
7 DDF (ulnar head)
8 Flex carpi ulnaris
9 Ext retinaculum
11 LCL
12 Accessory ulnar lig
13 Accessory IVCB lig
14 Accessory metacarpal ligL
ACB
Lateral aspect (joint capsule is removed)
L LCL
1/2/3/4 Dorsal intercarpal ligament
5 Prox lig ACB
6 Middle lig ACB
7/8 Distal lig ACB
9 Groove Lat ext T
10 Groove Ulnaris lat T
11 Interosseous lig
Lateral aspect (deeper dissection)
1 Groove to the CDET2 Ext dig lat T3 Flex carpi ulnaris T5 Accessory radial (cubital) lig6 Groove to the ulnaris lateralis T8 ICB9 Dorsal intercarapal ligament (ICB and UCB)10 UCB11 LCL12 Accessory UCB lig14 IIICB15 Dorsal intercarpal lig (III and IVCB)17 Accessory IVCB lig18 Accessory metacarpal lig19 Dorsal metacarpal lig
ACB
L
IV
Frontal section
1 Medial Palmar Intercarp lig2 Lat Palmar Intercarp lig3 Radiocarpal lig4 Lat collateral branch5 Transverse intercarp lig6 Palmar carpometacarpal lig
Medial aspect (joint capsule is removed)
Ca ACB
M MCL
MC II IIMB
MC III IIIMB
C3 IIICB
Cr RCBR Radius
Carpal Canal
• Palmar annular ligament / Carpla flexor retinaculum
– Connective tissue
– Encloses:
• SDFT and DDFT
• FCRT
• Involved in the carpal sheath
• Nerves and blood vessels
Carpal Canal
• Palmar annular ligament / Carplaflexor retinaculum
– Originates from the palmar border of ACB and inserts medially at the palmar aspect of the CB + MCL
• It it subdivided in several compartments
– Proximal border: level of proxmargin of ACB
– Distal border: close to the head of splint bones
Lateral View
Dorso-palmar View
DLPMO View
DMPLO View
Flexed Lateral View
DPDD View – Distal Radius
DPDD View – Prox Row
DPDD View – Distal Row
DMPLO
DMPLO
DLPMO
PMDLO
DLPMO
Lateral
Lateral
Cranio caudal