Hand Flashcards
Significance of proximal palmar crease?
Appx site of the superficial palmar arch
Significant of distal palmar crease?
site of MCP joints (dorsally)
Bennett’s fracture. Deforming force?
Base of thumb metacarpal fx (type 1): intraarticular fracture with proximal and radial dx of 1st metacarpal. Triangular bone fragments. APL deforms
Rolando fracture. Complications?
Base of thumb metacarpal fx (type 2): Intraarticular fracture with Y-shape. DJD after
Flexed fingers point to:
Tuberosity of scaphoid
Most common metacarpal fracture? Most common anatomic location?
5th MC Neck of MC
Boxer’s fracture?
Base of 5th MC
Gamekeeper’s thumb
Thumb MCP joint proper ulnar collateral ligament injury from forced radial deviation. Ski pole injury often. Stener lesion seen. Test at 30° flexion
Stenor lesion?
When adductor aponeurosis falls under torn ulnar collateral ligament, producing a palpable mass.
Mallet finger?
Rupture of the extensor tendon from distal phalanx. Bony avulsion from EDU seen.
Jersey finger?
FDP avulsion from P3 (avulsion fracture from volar base of P3)
Flexor tendon zones I-V and Thumb I-III
I: distal to FDS inertion II: Flexor retinaculum. No man’s land. avoid A2 and A4. III: Palm. IV: Carpal tunnel. Release and repair TCL during repair V: Wrist and forearm. Thumb I: Distal to FPL insertion Thumb II: Thumb flexor retinaculum. Preserve either A1 or oblique pulley Thumb III: Thenar eminence. Do not operate in this zone due to recurrent motor branch of median n
Extensor tendon zones I-IX
I: DIP joint. Mallet finger II: Middle phalanx III: PIP joint. Central slip injury. If triangular ligament is disrupted, lateral bands migrate volarly resulting in boutinniere finger. IV: Proximal phalanx V: MCP joint. Injury from fight bite. Repair tendon and sagittal bands as needed VI: Metacarpal. VII: Wrist VIII: Distal forearm. At MSC jxn IX: proximal forearm.
Draw flexor tendon sheath
A1 MCPJ, A2 proximal phalanx, A3 PIPJ, A4 middle phalanx, A5 DIPJ.
What can cause trigger finger?
Tight A1 ligament
Significance of Anterior oblique CMC ligament?
Ulnar side of 1st MC base to tubercle of trapezium. Beak ligament. Holds fragment in Bennett’s fx. Primary restraint to subluxation.
Significance of dorsal radial CMC ligament?
Dorsal trapezium to dorsal MC base. Strongest ligament. Torn in dorsal dx.
Cam effect in MC head and collateral ligament
Tight in flexion, loose in extension
Significance of Grayson’s ligament
Volar to neurovascular bundle, stabilizes skill in NV bundle.
Sig. of Cleland’s ligament
Dorsal to NV bundle. Stabilizes skin during flexion/extension.
Flexion and extension of MCP joint muscles
Flexion - IO muscles + lumbricals
Extension - extensor digitorum via sagittal bands
Flexion and extension of PIPJ and DIPJ
PIPJ - flexion via FDS and FDP,
extension via EDC and lumbricals via lateral bands
DIPJ - flexion via FDP,
extension via EDC and oblique retinacular ligament.
Parona’s space
Between flexor tendons and PQ. Possible horseshoe abscess.
Heberden’s and Bouchard’s nodes
Seen in OA. Heberden’s at DIPJ (more common), Bouchard’s at PIPJ.
MCP nodes
Seen in RA
Dupuytren’s contracture
Flexion contracture of 4th and 5th fingers. Palpable nodules. Caused by myofibroblast proliferation creating cords of type 3 collagen.
Four cardinal signs of Kanavel
Sings of purulent tenosynovitis: 1) Pain on extension 2) Fusiform swelling 3) Slight flexion 4) Tenderness along tendon sheath
1/2LOAF1/2
Median n innervates (motor recurrent branch) 1/2 lumbricals Opponens pollicis Abductor pollicis brevis 1/2 flexor pollicis brevis
Hoffman’s sign
Flick middle finger DIPJ into flexion. If thumb IPJ flexes, myleopathy
Profundus test
Stabilize PIPJ in extension, flex DIPJ only. FDP pathology
Sublimbus test
Extend all fingers, flex one PIPJ at a time. FDS pathology
Froment’s sign
Hold paper with thumb and index finger. Pull paper. If thumb IP flexion is positive, suggest adductor pollicis weakness/ulnar nerve palsy.
CMC grind test
Axial compress and rotate CMC joint. Pain = arthritis
Finger instability test
Stabilize proximal joint, apply varus/valgus stress. Laxity=collateral ligament instability
Thumb instability test
Stabilize MCP, apply valgus stress in extension and 30° of flexion. Laxity at 30° indicates ulnar collateral ligament injury. Laxity in extension indicates accessory collateral/volar plate injury
Brunnell-Littler test
Extend MCPJ, passively flex PIPJ. If easier to flex PIPJ in MCPJ flexion, tight intrinsic muscles
Elson test
Flex PIPJ 90° over table edge, resist P2 extension. If the DIPJ extends (via lateral bands) indicates central slip injury (boutonniere)
Which lumbricals are unipennate vs bipennate
1/2 are unipennate (median nerve) 3/4 are bipennate (ulnar nerve)
What are the actions of dorsal and palmar interossei
DAB PAD
Innervation of FPB
Deep head by ulnar n, superficial head by median n.
Radial and Ulnar artery continuation in the hand.
Radial artery’s deep branch runs through the 1st dorsal interosseous and becomes the deep palmar arch. Ulnar artery’s superficial branch branch terminates as the superficial palmar arch
Relationship of deep and superficial palmar arches?
Superficial arch is distal to deep arch. Limit of superficial arch is called Kaplan’s line.
Kaplan’s line?
Distal limit of superficial palmar arch
Swan neck deformity cause
FDS insertion/volar plate injury, associated with RA.
Boutonniere deformity cause
Central slip of EDC and triangular ligament injury. Lateral bands subluxate volarly which hyperflexes PIPJ.
Common bacteria in human/animal bites
Staph, strep Human: Eikenella Animal: Pasturella
Retinacular cyst
Ganglion type cyst of flexor tendon sheath.
Syndactyly
Failure of finger tissue differentiation (fused fingers)
Camptodactyly
Congenital finger flexion abnormality. Usually PIPJ of small finger.
Clinodactyly
Deviation of finger in coronal plane. Usually radial deviation of small finger. Due to delta shaped middle phalanx.
Preaxial polydactyly
Duplicate thumb. 7 types, #4 most common.
Constriction band syndrome
Bands lead to digit necrosis or diminished growth.
Volar approach to finger dangers
Digital artery/nerve, flexor tendons. NV bundle is lateral to tendon sheath.
Mid-lateral approach to finger dangers
Digital artery/nerve
