Anatomy:

• Common digital nerves deep to arteries in palm but become superficial distally; 
• Proper digital artery splits into three branches, two arches at nail fold, dorsal veins for drainage
• Quadrigia effect: restriction in flexion of adjacent digits, resulting from common muscular origin of profundus tendons (prevent by not advancing FDP distally) when FDP attached to distal stump
• Lumbrical plus deformity: extension at the PIP with attempted flexion results from retracting FDP and lumbrical origin, increasing lumbrical pull –> treatment includes sectioning or division of the lumbrical muscle (proximal retraction of FDP pulling on lumbrical tension)
• Can be caused by amputations, FDP interposition grafts, lengthening procedures

Digital Replantation: 

Indications: 

• Should be attempted in a child (except for when it is severely crushed or there are other life-threatening injuries that preclude surgery
• Thumb
• Multiple digits
• Finger distal to FDS
• Contraindications: single proximal to FDS, multiple segmental injury of, acute life threatening injuries are the only true contraindication for thumb replantation, (relative) in workers who need to return to work quickly
• Amputated digits can tolerate cold ischemia up to 24 hours (6-12 warm)
• In patients with amputations order of fixation: fasciotomies, bone, artery, vein, nerve; if presenting late –> arterial shunting with silastic shunt etc
• Make sure amputated limb is cool until microvascular anastomosis are completed
• Replantation of multiple digits- structure by structure bone  first, tendon, artery then nerve, veins
• If there is an extensive zone of injury or avulsion mechanism, use of vein grafts permit anastomosis outside this zone of injury and increase chances for success
• Mechanism of injury is most predictable factor for success in replantation, psychotic disorders, PVD, and electrolyte imbalances are risks for failure
• Only factor correlated with survival in replantation is the repair of 2 or more dorsal veins
• Heterotopic replantation: can be used for multiple crush injuries or segmental injuries of thumb
• Venous congestion immediately after replantation –> take off dressings first, then suture removal then leeches
• Remember to perform proper work up of trauma patients prior to digital replantation (Cspine Xrays in MVCs)

Amputations:

• Composite grafting: nonmicrosurgical replant of amputated finger, between 2-6 years
• Amputate to the level of good vascular tissue to cover; index finger may be given curved ray amputation for good opposition of middle finger
• Ring Avulsion injuries: 
• 1: circulation adequate, 2: circulation inadequate, vessel repair needed, 3) complete degloving, amputation required
• Type three avulsion injury of ring finger –> use long finger ulnar digital artery based revascularization
• Most successful avulsion replantation involves resection of injured vessels and vein grafting
• Ray amputation: small and long finger gap closed by suturing the deep intervolar plate ligaments (deep intermetacarpal ligaments) or ray transposition 
• Ray amputations are most aesthetic
• History of renal failure/kidney transplantation is associated with the highest risk of amputation in diabetic patients with hand infections
• Transposition of index finger to long finger best accomplished at level of metacarpal base –> higher rates of bony union 
• Wrist disarticulation versus transradial amputation: wrist disarticulation preserves DRUJ and improves forearm rotation although it may be difficult for fit of prosthesis (limb length discrepancy, and patients are more likely to abandon their prosthesis)
• Targeted muscle reinnervation: provides better prosthesis control by input of median and ulnar nerve signals
• Resected nerves (like median and ulnar), can be coapted to nerve branches to remaining muscles like pectoralis and deltoid. Transcutaneous EMG detectors are positioned over these re-innervation sites to detect nerve signals
• Minimal stump length for elbow function is 5-10cm

Nail Bed:

• Hyponychium: junction of nail bed and fingertip skin beneath the distal margin of the nail
• Perionychium: extends along lateral borders of nails
• Eponyhcium, distal part of nail fold where it attaches to the surface of the nail
• Lunula: white arch just distal to eponychium
• Trephination: subungual hematoma that is painful –> aspiration, if nail is torn than nail must be removed
• Nail growth = 0.1mm per day, grows in three months
• Crush injuries: nail bed lacerations most closely associated with fracture of distal phalanx; most patients with subungual hematoma have nail bed laceration
• primary repair; crush injuries or avulsion injuries of nail bed must be debrided, then split matrix grafting from un-injured portions of nail bed
• Germinal matrix grafts for germinal matrix of the nail
• Split matrix grafting used for sterile matrix nail reconstruction in patients with bifid nails or eponychial/hyponychial pterygium (scarred/nonadhered)
• Split nails may undergo excision and primary closure if small, if greater than a third or up to a third need grafting
• For sterile matrix reconstruction, split grafting from toe may be used. When germinal matrix involved, full thickness grafting needed
• Pincer/trumpet nail deformity: excess transverse curvature of nail and pinching of soft tissue of distal fingertip –> remove nail plate, elevate nail bed from sides of distal phalanx, dermal grafts placed under lateral/medial portions of nail bed
• Hook deformity: 
• Hook nail occurs due to lack of bony support or loss of sterile matrix need 2mm of tuft distal to sterile matrix
• cross finger flap and bone graft; nail supported by dorsal tuft of DP, caused by tight closure of fingertip amputation and excessive palmar tension at hyponychial-pulp suture –> avoided by excision of redundant nail bed to 2mm support of tuft, use VY flap for closure
• If sterile matrix deficient than sterile matrix graft
• Lateral paronychial releasing incisions with central advancement flap can be used for Full thickness losses around 4mm
• SCC of the nail bed: amputation of the entire distal phalanx (chronic paronychia typically fungal infection –> if does not respond biopsy); other SCC of hand 1cm margins
• Other nail deformities: psoriatic arthritis: (crumbling of nail plate, leukonychia, and onycholysis)

Soft Tissue Defects

• Healing by secondary intention: useful for wounds less than 1.5cm with no exposed bone
• has the best recovery of sensation
• Dressing should include weekly semi-occlusive dressing (tegaderm), daily hydrogen peroxide can limit the wound healing and cause drying out
• Return of sensation after excellent after FTSG
• Atasoy-Kleinert flap: homodigital VY advancement of volar pulp tissue in transverse or oblique fingertip injuries, contraindicated in volar injuries
• Atasoy VY for dorsal oblique
• Can only advance distal edge 1cm 
• Can have near normal sensibility
• V-Y advancement flap requires volar skin and more dorsal loss
• Homodigital island flap: raises skin/fat overlying one digital NV bundle that can be advanced over distal pulp defects of fingers (needs both arteries to be present)
• Reverse homodigital island flap is a distally based flap to repair fingertip injuries (pedicle based on CONTRAlateral digital artery)
• Provides immediate near normal sensibility
• Kutler flap: bilateral VY advancement flaps, advancement of tissue from sides of finger (sensate)
• Good for lateral oblique injuries on distal finger
• Heterodigital island flaps: violates normal digit (like homodigital but from separate finger) sensbility not as good
• Used for ulnar thumb pulp defects and requires cortical relearning 
• Cross Finger Flap: entire volar surface of distal phalanx distal third, should not be used in workers that need good hand function post-operatively if bone is exposed
• Cross finger flaps best if used in younger patients due to risk off flexion contractures
• useful for large volar injuries, elevated from adjacent finger on dorsum middle phalanx, just dorsal to paratenon, then pedicled transfer to adjacent finger, inset –> division at 8-10 days, sensibility poor 
• Reverse cross finger flap: covers dorsum of finger, recipient dorsum middle phalanx receives skin graft
• Adipofascial turndown: good for small dorsal defects of the finger; base of flap is proximal to the defect, covered with STSG
• Flag flap: used for proximal phalanges or metacarpophalangeal joints
• Thenar flap: used for large volar oblique injuries of index and middle fingers, skin sq elevated over palm and inset–> flap division at 10-14 days
• Adduction contractures of the thumb: complete contracture release and resurfacing
• Web space deepening useful in patients with distal thumb amputations and good motion –> via four flap z plasty
• Reverse PIA best choice for adduction contracture or for dorsal hand wounds if large
• FDMA may be used if small, may also consider resection of FDI
• First web space flap harvested from medial aspect of great toe (first dorsal metatarsal artery)-uses saphenous vein for outflow
• toe pulp flap- metatarsal arteries and saphenous system- innervated by deep peroneal nerve
• Useful for wounds > 50% volar and dorsal parts of thumb, finger. Provides sensation
• Mangled hand injuries: must consider all aspects (including comorbidities). Consider fastest option in those that are sick (filet flaps, avoidance of free flaps, avoidance of things that will need several procedures etc etc)
• For dorsal hand coverage PIA flap may be taken with ulna and EPL

Thumb Reconstruction: 

• Moberg Flap: for volar/distal thumb defects up to 2cm (if islandized, 1.5cm otherwise) , <50% of volar surface, sensory innervated skin, proximal donor site management with FTSG or VY, may be used to cover exposed bone, sensate; harvested with 2 digital arteries and 2 digital nerves –> splint in flexion 2-3 weeks

• Moberg has axial pattern blood supply
• Most common complication after moberg flap is extension deficit at IP joint
• Cross finger flap may be used for distal volar defects of the thumb (entire volar surface), not sensate
• NV island pedicled flap (littler flap): distal ½ innervated; most commonly for ulnar  thumb defects, typically closest digital artery next to aid in tension free transfer (perform allen’s test), cortical relearning in only 40%
• First dorsal metacarpal artery flap: <4cm coverage, innervated skin distal 1/3 thumb, dorsum, volar, degloving injuries, first web space
• includes superficial radial nerve to provide protective sensation, artery (first dorsal metacarpal artery)courses within the fascia of the first dorsal interosseous muscle (snuff box bordered by first and third extensor compartments)
• Kite Flap: based off of first dorsal metacarpal artery (variation of first dorsal metacarpal artery flap), includes rhomboid flap to close donor site ** web space and dorsum of thumb, can also use on volar aspect, superficial radial nerve branch/dorsal digital nerve branch
• Reverse radial artery flap also great for thumb reconstruction 
• Pollicization: useful for injuries through thumb CMC (remember pollicization reconstructs CMC joint)
• Index metarcarpal base becomes CMC, prox phalanx metacarpal, middle phalanx prox phalanx**
• leads to decreased grip strength
• Also good option in those that cannot undergo microsurgical reconstruction
• Toe to thumb: first dorsal metatarsal artery (branch of dorsalis pedis)–> dominant blood supply to both first and second metatarsal
• Second toe transfer or (flap) best aesthetic and functional improvement for thumb reconstruction
• Need thumb metacarpal base
• Groin flap insensate, not ideal for thumb reconstruction

Dupuytren’s Disease: AD, white males, family history, associated also with plantar fibromatosis and peyronie’s

• Ring and small fingers typically affected
• Myofibroblasts responsible for cord formation in dupuytren’s
• Three stages: 1)nodule formation (type III collagen) 2) cord formation without contracture 3) mature cord with contracture 
• Clelands ligaments do not become involved
• MP joint: pretendinous cord, or pretendinous portion of spiral cord
• PIP: central (continuation of pretendinous fibers of palm to digit IE central cord), spiral (pretendinous band, spiral/lateral sheet, Grayson’s ligament, displaces NV bundle superficial and central in the finger) and lateral cords  (runs from nataory ligament to the lateral digital sheet), 
• Retrovascular cord: contracture of DIP
• Dupuytren’s nodule: associated with plantar fibromatosis, painful lesions can be treated with corticosteroid
• Fascial structures that encase the neurovascular bundles of finger: cleland’s, grayson’s, lateral digital sheet, retrovascular band
• Natatory ligament causes adduction contractures of the hand
• Natatory cord: passes across palm and attaches to each individual flexor tendon sheath, patients with natatory ligaments have limited finger abduction and PIP flexion contractures
• NV bundles shorten –> any contracture release must be done with caution to ensure perfusion
• small finger cord originates from abductor digiti minimi musculotendinous junction
• PIP contracture treatment: release of checkrein ligaments of PIP joint (extensions of the volar plate), followed by accessory collateral ligament, manipulation
• Evaluation
• Hueston’s tabletop test: + if patient is unable to place all fingers in flat position on tabletop simultaneously
• Treatment
• Non-op Treatment: steroids for isolated painful nodules
• Dynamic extension splinting for non-operative treatment, can also use collagenase, steroids,  continuous skeletal traction,
• Non op treatment typically not effective
• Surgery for MP contracture > 30-40 degrees , any PIP contracture is indication for surgery
• Surgical: limited fasciectomy has longest
• Collagenase: corrects flexion deformities of MP –> PIP has higher rate of complications (particularly small finger) 
• collagenase (clostridium histolyticum) injection followed by manual extension 24 hours- one cord at a time- better for MP, 
• Injectable collagenase indicated for adult patients with finger contracture and palpable cord
• Rupture of FDP can occur with injection of collagenase at PIP (especially small finger)
• For paresthesias or numbness, observe for 8 weeks prior to intervention
• Needle fasciotomy
• Needle fasciotomy with lipofilling: works by reducing myofibroblast contact, inhibits myofibroblast proliferation
• NV injury in dupuytrens is 1.5%, regional pain syndrome 8%, most common complication is recurrence 

Vascular Disease

• Patients where radial artery cannulation had 0.1% permanent ischemic damage or pseudoaneurysm
• Most likely complication of brachial arterial monitoring: parasthesias in median artery brachial artery travels adjacent to median nerve (MAT)
• Scleroderma or primary systemic sclerosis: shiny skin and stiffness of joints, can lead to ulceration of fingertips, associated with Raynauds phenomenon; CREST 
• Tip ulcerations from scleroderma treated conservatively with debridement and limited resection of bone; if fails to respond then amputation and possible digital sympathectomy
• Raynauds: primary (idiopathic), secondary (known cause like autoimune disorder) vasospastic disorder with triphasic color of skin, symptoms must be present for 2 years 
• Thought to be due to hyperactive sympathetic activity
• First line treatment is calcium channel blocker (IE nifedipine), followed by botox or digital sympathectomy (around radial ulnar and digital arteries) if ulcers and ischemic changes
• Botox inhibits rho and rhokinase activity; injection site is perivascular in the palm (10U each)
• SLE: arthralgias and swelling of joints
• Hypothenar hammer syndrome: thrombosis of ulnar artery in Guyon’s canal, true aneurysm, from crush injury –> angiography or duplex, presents as pain in region of hook of hamate bone, parasthesias and decrease in temp in ulnar distribution, ischemia of digits
• Seen in repetitive trauma –> evaluated with angiography (see tortuosity of ulnar artery)
• may be treated with medical management at first (cessation of smoking and trauma, CCB, antiplatelet), always surgical if ulceration or DBI <0.7
• Resection of thrombosed segment and reconstruction with grafting (ulnar and proximal superficial arch) 
• Complex regional pain syndrome: stage I: pain out of proportion, hyperesthesia, edema, erythema, hyperhydrosis II: dystrophic phase months 3-9 stiffness, edema, altered blood flow and osteopenia, III: increased stiffness, pale/cool dry skin and decreased pain
• Bone scan for CRPS shows increased periarticular uptake on third phase, phase 1/2 shows autonomic dysfunction
• Tool in confirming diagnosis of CRPS is third phase on three phase bone scan, increased uptake, typically elevated sweat and increased temperature, osteoporosis in 3-5 week
• AV fistula reconstruction, ligation with reconstruction with vein grafting, diagnose with duplex or MRA
• Superficial arch thrombus: usually embolectomy and anticoagulation, fasciotomy if prolonged 
• Digital block: can cause digital ischemia –> use alpha adrenergic ANTAgonist like phentolamine
• Used to reverse effects of epinephrine hours to days after use
• Inject 1-2mg in area (locally)
• Ischemic limb: begin with ASA and heparin immediately before consideration of OR (embolectomy TPA etc)
• Compartment syndrome: 5 P (pulselessness, paresthesias, pallor, pain out of proportion to exam, paralysis) fasciotomy recommended if compartment pressure exceeds 30mmHg, or difference between diastolic and compartment pressure <30
• Compartment pressure evaluated by manometry
• After 4 hours of ischemia need to consider prophylactic fasciotomies –> can occur after crush injuries, arterial reconstruction
• Need to consider early release of median nerve and guyons
• More than 100 cc of infiltration has been associated with compartment syndrome
• May observe with elevation if if symptoms are mild
• Decision for fasciotomy after infiltration is mainly persistent pain
• Volkmann’s contracture: can present after 6-12 hours of ischemia (ie compartment syndrome), affects deep flexor compartments first FPL/FDP first, superficial flexors next and superficial extensors (brachioradialis/ECRL/ECRB/EDC/ECU last)–> manifests weeks later as flexion at elbow and wrist, pronation of forearm, adduction/flexion of thumb, extension at MP flexion at IP, loss of sensation from median and ulnar nerve– > treat with exploration for forearm, neurolysis of median and ulnar nerve and muscle sliding or tendon lengthening procedure
• Treat with physiotherapy, followed by debridement of muscle, muscle slide and tendon lengthening (for select cases), tendon transfers and free innervated muscle transfer for extreme cases
• Botox for spasticity after anoxic brain injuries followed by transfer of FDS to FDP

Miscellaneous

• Best STSG donor site dressing: occlusive dressing with hydrocolloid polymer complex (duoderm), opsite or tegaderm minimizes discomfort; semipermeable favorable for infection and re-epithelialization
• Hand transplant rejection: hyperacute: rejected within minutes to hours due to preformed antibodies (thrombose capillaries); acute humoral rejection: rapidly induced after exposure to the graft (antibody mediated within days)- treated with plasmapheresis and anti B cell reagents; acute cellular (T cell) activated against donor antigens most common, 3-6 months), use increased doses of drugs; chronic rejection is both antibody and cell mediated
• Skin is most likely to elicit IgM/IgG immune response that results in cellular destruction
• High pressure paint injuries- do not use mineral oil – toxic to skin; requires debridement and serial dressing changes 
• High complication rate, risk of amputation nearly 90% if treated nonoperatively
• Leech therapy: aeromonas, produce beta- lactamase. Use cipro in adults, ceftriaxone in children (tetracyclines and augmentin have high resistance), can use bactrim, cephalsporin, aminoglycoside (3rd generation)
• Leech use: ciprofloxacin for prophylaxis (aeromonas