`Describe the blood supply to the scaphoid? What is the main supply?
Dorsal carpal branch of the radial artery is the main - supplies 80% Also: Superficial palmar branch of the radial artery
Which ligament is violated and must be repaired in the volar approach to the scaphoid?
Which ligament is the strongest ligament that resists perilunate dislocations in the wrist?
Long radiolunate ligament
What is the weakest point in the volar wrist?
Space of Poirier
What is the significance of the Space of Poirier?
It is the weakest point in the volar wrist and is where volar lunate dislocations occur most often.
Where is the Space of Poirier located?
Volar wrist at the junction of the Lunate and Trapezium/Trapezoid
Bordered by the Radiocapitate & Radiolunotriquetral ligaments (aka long radiolunate)
What "ligament" in the wrist is actually a neurovascular bundle?
What are the components of the radioscapholunate ligament?
Vascular branches of the anterior interosseous and radial arteries Nerve branches of the anterior interosseous nerve
Where is the radioscapholunate ligament found?
Between the long and short radiolunate ligaments, piercing the joint capsule
What are the components of the TFCC?
Triangular fibrocartilage disc (articular disc)
Meniscus homolog (disc-carpal ligaments)
Volar Ulnocarpal ligaments (ulnolunate & ulnotriquetral)
Dorsal and volar Radioulnar ligaments (palmar & dorsal, each with a superficial & deep component)
What is the ligament of Testut?
Radioscapholunate ligament. Actually a neurovascular bundle with no contribution to carpal stability
What are the contents of the anatomical snuffbox?
Radial artery Sensory branch of the radial nerve Wrist joint capsule Fat
What are the borders of the anatomical snuffbox?
Trianglr: Anterior: EPB, ABL Posterior: EPL (extensor compartments 1&3) Base: radial stylus process Floor: scaphoid & trapezium
What are the stabilizers of the DRUJ?
ECU tendon & Subsheath
Superficial radioulnar ligaments - origina at ulnar styloid
Deep radioulnar ligaments (ligamentum subcruentum) origin at fovea
What are the components of the scapholunate ligament?
Dorsal (strongest) Palmar Proximal (thin, membranous)
What is a lesser arc injury?
Purely ligamentous perilunate injury
What is a greater arc injury?
Fracture around the lunate - scaphoid, capitate, hamate, triquetrum
What are the extrinsic ligaments of the dorsal wrist?
Dorsal radiocarpal ligaments Dorsal intercarpal ligaments
What is Kienbock's disease?
Avascular necrosis of the lunate.
Why do perilunate dislocations usually NOT end up in AVN?
Because it has a rich blood supply including: Dorsal and volar radial branches Branches of the dorsal and volar intercarpal arch Anterior interosseous artery
How many articulations does the scaphoid have?
5 Radius, capitate, lunate, trapezoid, trapezium
What is intersection syndrome?
Overuse condition affecting the second dorsal compartment - ECRL and ECRB
What is DeQuervain's tenosynovitis?
Inflammation of the tenosynovium of the abductor pollicis longus and extensor pollicis brevis tendons
Affects 1st dorsal compartment
Diagnosed with Finklestein's test - Increase in pain when the thumb is held in palm and wrist is ulnarly deviated - Pain is over the radial side of the wrist (1st dorsal compartment)
What is Wartenberg's Syndrome
Radial neuritis - Neuritis of the superficial branch of the radial nerve - Inflammation due to stretch, compression or direct blow - Compression occurs between the brachioradialis and ECRL
Describe Eaton's classification of the radiographic stages of thumb CMC OA
2: Joint spacer narrowing, osteophytes 2mm
3: Joint space narrowing, osteophytes >2mm
4: pantrapezial arthritis
What is the bony articulation of the distal radioulnar joint?
Sigmoid notch of the radius articulation with the ulna
i.e. "lesser" sigmoid notch
What are the stabilizers of the distal radio-ulnar joint (DRUJ)?
- Bony integrity between sigmoid notch of the radius and ulna - Interosseous membrane - TFCC - Joint capsule - Pronator quadratus - Extensor carpi ulnaris
What are the muscular attachments of the proximal row of the carpal bones?
What carpal bones do not contribute to carpal motion?
Pisiform: it's a sesamoid bone of the flexor carpi ulnaris
The Pisiform is a sesamoid bone for what tendon?
Flexor carpi ulnaris (FCU)