Hand Flashcards
Sagittal Band Rupture
Most commonly involved?
Presenation?
Function of SB?
- Radial sagittal band of long finger
- dislocation of extensor tendon during MCP flexion w/ wrist flexed.
- inability to initiate extension, but can hold mcp in extension once placed there.
- PSEUDO triggering
- tx: acute injury splinting of MCP (extension splint/yoke splint for 4-6 weeks); chronic injury or athelete direct repair vs extensor centralization
functions:
* Primary stabilizer of extensor tendon at MCP jt (juncturae tendinum secondary stabilizers)
* resists ulnar deviation of tendon during flexion and bowstringing during extension.
* complete Radial SB sectioning leads extensor dislocation, 50% sectioning of proximal SB leads to extensor tendon subluxation.
complications: MC flexion contracture, from non-op or delayed secondarily intrinsic tightness develops.
RA hand: sagittal band dysfunction leads to ulnar deviation of digits
Diagnosis is made clinically with the inability to initiate MCP extension but the ability to hold MCP in extension once passively extended. In sagittal band rupture, the extensor tendon may subluxate into the valley between the metacarpal heads. The patient will not be able to actively extend the MCP joint from a flexed position with the subluxated tendon, but will be able to maintain MCP extension after it has been passively extended. Extensor lags can have other etiologies other than extensor digitorum communis subluxation such as tendon laceration or rupture, posterior interosseous nerve palsy, but in these conditions, patients cannot maintain MCP extension. Active interphalangeal extension can be achieved with the intrinsic muscles that are not affected by sagittal band rupture.
Scaphoid fractures:
Most common Mechanism of force?
Blood supply?
Imaging: Repeat xrays? Best Xray position? Most sensitive test?
Dorsal approach for?
Volar approach for?
Screw?
AVN rates?
Nonunion rates?
Mechanism: axial load across a hyper-dorsiflexed, pronated and ulnarly-deviated wrist
Blood supply: dorsal carpal branch (radial a.) 80% of blood supply of scaphoid via retrograde blood flow (distal to proximal)
Distally, distal tubercle- superfiscial palmar arch, br of volar radial a.
Repeat xrays 14-21 days if high suspicion,
xray postion: wrist extension & 20 deg ulnar deviation to nuetral PA of wrist. MRI most sensitive less than 24 hrs
CT w/ 1 mm cuts along scaphoid axis to eval for progression of nonunion or union after surgery.
Approaches:
Dorsal: best for proximal pole fxs, higher risk of unrecongnized screw penetration of subchondral bone.
Volar: waist & distal pole, humpback flexion deformitions, avoids jeopardizing scaphoid blood supply. RSC ligament must be incised and repaired.
Rigidity optimized by long screw placed down central axis.
cannulated compression screw in central scaphoid via dorsal approach, biomechanically advantageous and provides greater stability
AVN rates w/o treatment: proximal 5th 100%, proximal 3rd 33%
Union rates of 90-95% with operative treatment.
Scaphoid complications?
Nonunion: incidence risk factors? treatment?
Osteonecrosis?
Malunion?
Subchondral bone penetration w/ arthrosis and prominent hardware?
scaphoid fx
Nonunion in young patient: tx?
typically manifests as?
How to assess?
Rate of success?
Salvage option? contraindication for this?
Hook of hammate fx
xray? RF and mechanism
carpal tunnel view
RF: golf, baseball, hockey
Direct blow to volar palm (grounding a club in golf)
: Patient positioning for carpal tunnel radiograph-wrist is extended 70 degrees, and beam is angled 25-30 deg to the long axis of the hand(arrow).
TFCC
mechanism of injury:
symptoms?
Exam?
What structure is most important restraint of dorsal/palmar translation?
Type 1. Fall on extended wrist in pronation
Type 2. Positive Ulnar variance; ulnocarpal impaction
symptoms: pain w/ door key,
* positive “fovea sign” TTP soft spot b/t ulnar styloid and FCU tendon, between bolcar surface of ulnar head and pisiform
* Pain w/ ulnar deviatin
Tx:
- all traumatic injuries with a stable DRUJ are initially treated with a course of immobilization, NSAIDS, corticosteroid injections, and physical therapy.
- Dorsal and palmar radioulnar ligament: primary restraints to translation of radius on ulna
AAOS: Clinical examination of the distal radioulnar joint is frequently described as translation of the ulnar head in reference to the radius. This description is incorrect, since the ulna is the bone that is fixed in space. Anatomically speaking, the radius moves in relation to the fixed ulna. The triangular fibrocartilage complex is composed of all of the structures listed above. The articular disk is a meniscal-like structure that serves a load-bearing function between the ulnar carpal bones and the ulnar head. About 20% of the load borne across the wrist passes through the disk. It has almost no ligamentous (stabilizing) function. At the dorsal and volar margins of the articular disk are thickened true ligamentous ligaments termed the radioulnar ligaments. They take origin from the foveal area of the ulnar head and styloid and insert into the dorsal and volar margins of the sigmoid notch. These two ligaments serve as primary restraints to dorsal and palmar translation of the radius on the ulna. The ulnolunate ligament, ulnotriquetral ligament, and the subsheath of the sixth extensor compartment are ligaments, but they serve to stabilize the carpus to the ulna and radius. They provide minimal stability to the distal radioulnar joint.
Phalanx dislocation
Dorsal disclocations:
Volar dislocations:
What can happen in a rotatory volar PIP jt dislocation?
Dorsal DIP jt dislocation: prevention of reduction?
Dorsal Dislocations:
* tearing of collateral ligaments and shearing of volar plate
* volar plate and block reduction
* volar plate disruption – swan neck deformity
Volar dislocation: buotonniere deformity
-simple: central slip disruption
-rotatory rupture of one collateral ligament, proximal phalangeal condyle buttonholes between central slip and lateral band
reduction of rotatory: flex mcp and PIP 90 with traction relax volarly displaced lateral band
tx: splint in PIP jt ex, w/ full ROM of mcpj and DIPJ to allow for healing fo central slip.
Dorsal DIP jt dislocatin: volar plate interpositional can prevent reduction
tx:
Buddy taping(splinting):
- adj finger 3-6 weels if dorsal dislocation stable after reduction or lateral dislocation
Extension block splinting if dorsal dislocation unstable
extesnion splinting 6-8 weeks if volar dislocation
Phalanx Fracture dislocation:
Most important determinant of outcome?
Most common fracture and tx?
- maintenance of alignment on of middle phalanx on lateral
- Volar lip of P2:
- less than 40% jt involved or joint stable after reduction: dorsal extension block splint with active flexion and extension
- more than 40% jt involved or joint unstable = crrp orif
Proximal phalanx fx: what kind of deformity?
Oblique proximal phalanx fx?
apex volar deformity (flexion of proximal frament through lumbrical, extension of distal fragment through central slip) extensor lag–> corrective osteotomy to improve active PIP extension
Unstable oblique proximal phalanx fx( scissoring with flexion): K wire?
What anatomic structure must be excised when performing a volar plate arthroplasty of the proximal interphalangeal joint?
The collateral ligament must be excised or released from the proximal phalanx to allow gliding of the middle phalanx on the articular surface of the proximal phalanx. Failure to do so may prevent this gliding motion and make the middle phalanx just hinge on the proximal phalanx.
A 30-year-old woman injured the ring finger of her nondominant hand while playing baseball 5 weeks ago. She now reports pain and limited motion of the proximal interphalangeal (PIP) joint. A lateral fluoroscopy image is shown in Figure 36. Treatment of the PIP joint should consist of
The patient has a neglected PIP joint fracture-dislocation with comminution involving more than 40% of the volar articular surface of the middle phalanx. Volar plate arthroplasty has been advocated for the treatment of acute unstable and chronic dorsal fracture-dislocations. The volar plate is incised laterally and released from the collateral ligaments. The volar fragments of the middle phalanx are removed and a trough is created for advancement of the volar plate, which is secured with sutures secured on the dorsum of the middle phalanx beneath the extensor mechanism.
A 38-year-old man caught his index finger in a volleyball net. He noted an angular deformity of the finger that was reduced when a teammate pulled on his finger. Three weeks later, he now reports trouble extending his finger. A clinical photograph is shown in Figure 55. What anatomic structure is most likely injured?
Central slip
The clinical photograph shows a classic boutonniere deformity. It is likely that the patient sustained a volar dislocation of the proximal interphalangeal joint, with a concomitant rupture of the central slip insertion of the extensor tendon.
Metacarpal fractures
Most important consideration for non op?
ORIF in athlete?
“psuedo clawing”
effect of transverse intermetacarpal ligament?
contributor to extension lag?
what is the effect of shortening of metacarpal fractures?
- no rotational deformity
- most isolated metacarpal fractures can be treated nonsurgically, multiple metacarpal fractures are inherently unstable due to the loss of support that an intact adjacent metacarpal provides; therefore, treatment should consist of surgical fixation of all three metacarpal fractures.
- Athlete w/ metacarpal fx: ORIF, faster return to play, no increase in union, grip strength, or ROM at final follow up
- Dorsal angulation of index and middle finger metacarpal fractures of 30 degrees: is less well tolerated than that of the ring and small fingers, which results in clinical “pseudoclawing” of the affected digit due to metacarpal phalangeal joint (MCPJ) hyperextension
- transverse metacarpal ligament is the primary restraint against the longitudinal shortening of metacarpal shaft fractures.
- Shortening of metacarpal fractures >2-5mm may result in extension lag at the MCP joint as well as reduced grip strength due to loss of tension on the extensor mechanism. 7-degree extensor lag for every 2 mm of metacarpal shortening
angulation less tolerated in shaft than neck fxs, angulation more than 10 should be reduced.
AAOS: effect of shortening Cadaveric models have demonstrated a 7-degree extensor lag for every 2 mm of metacarpal shortening, with the amount of lag increasing in a linear fashion. There was no statistical difference in the amount of lag in regard to the digit involved. Based on muscle length-tension relationships, cadaveric models have also been used to demonstrate an 8% loss of power secondary to decreased interosseous force generation with 2 mm of shortening. Because the intrinsic muscles of the hand contribute anywhere from 40% to 90% of grip strength, decreased interosseous force generation secondary to metacarpal shortening will invariably cause a decrease in grip strength.
Proximal phalanx fx: common deformity?
Indications for buddy taping or splinting phalanx fractures?
- shortened position may lead to an extensor lag at the proximal interphalangeal joint (PIP).Proximal phalanx fractures tend to fall into apex volar angulation due to the proximal fragment being flexed by the interossei (intrinsics) and the distal fragment being extended by the central slip. Extra-articular proximal phalanx fractures with less than 10° angulation, less than 2mm of shortening, and no rotational deformity can be treated non-operatively but those falling outside these parameters may require closed reduction percutaneous pinning vs. open reduction internal fixation (ORIF). If the fracture heals in an angulated or shortened position, this may lead to an extensor lag at the PIP joint due to the effective shortening of the extensor tendon. Soft tissue releases or a corrective osteotomy may be required in this case if symptomatic.
- Indications for buddy taping or splinting include extraarticular fractures with less than 10° angulation, 2mm shortening, no rotational deformity, and non-displaced intraarticular fractures.
- Indications for CRPP vs ORIF include extraarticular fractures with >10° angulation, >2mm shortening, rotational deformity, displaced intraarticular fractures, and unstable or irreducible fracture pattern.
A 47-year-old woman falls and sustains a direct blow to her middle finger. She notes pain and swelling and is unable to move the proximal interphalangeal (PIP) or distal interphalangeal (DIP) joints. Radiographs are shown in Figures 8a through 8c. Proper management should consist of
The oblique nature of the fracture and extension of the fracture to the condyles implies an unstable fracture. Lag screw fixation provides an excellent chance of union, and the ability to start early range of motion.
Jersey Finger
What’s injured?
exam?
treatment?
- traumatic flexor tendon injury caused by anavulsion injury of the FDP from the insertion at the base of the distal phalanx.
- finger that lies inslight extension at the DIPrelative to other fingers in the resting position.
- during grip ring fingertip is 5 mm more prominent than other digits in ~90% of patients
- tx:
*less than 3 weeks, direct tendon repair or tendon reinsiertion with dorsal button, advancement more than 1 cm risk of DIP flexion contracture or quadrigia - ORIF for avulsion injury
- 2 stage recon for chronic, more than 3 month injuries.
Thumb Collateral ligament injury
Mechanism of Injury?
Presentation?
Stener lesion?
two ligaments and how to test?
Tx?
radially directed force causing hyper abduction moment at mcp jt.
Pain with pinch or grip
Stener lesion: avulsed ligament w/ or without bony attachment is displaced dorsal and superfiscial to** adductor aponuerosis **
Proper U Collateral ligament: resists load in flexion. radial instability at 30 of flexion
Accessory U collateral ligament and volar plate: resists load in extension. radial instability in extension indicates injury to both and/or volar plate
Tx: immobilize 4-6 weeks less than 15 deg of varus/valgus
rcl/ucl repair for stener lesion, 15 deg of varus valgus, 30-35 opening
complications: stiffness most common problem, persistent instability, superfiscial radial neurapraxia
Hand infections
Pyogenic flexorteno:
Most common bug?
iv drug user bug?
human bites?
animal bites?
In the little finger and thumb the sheaths communicate with the?
What is parona’s space where does it lie?
Horse shoe abscess?
Prognosis of kanavel signs:
1 Staph Aureus
IVDU: MRSA (Gram positive cocci)
Human: Eikenella
Animal: Pasteurella (gram negative) tx ampicillin/sulbactam
In the little finger and the thumb, the sheaths usually communicate with the ulnar and radial bursae, respectively.
The potential space of communication,** Parona’s space**, lies between the fascia of the pronator quadratus muscle and flexor digitorum profundus conjoined tendon sheaths.
Horseshoe: if infection involves the thumb or small fingers (connection b/t sheath at wrist)
Infection tracking through this space presents as a horseshoe abscess
4 Kanavel signs, they found that fusiform swelling was most often present (97% of patients), followed by pain on passive extension (72%), semiflexed digit posture (69%), and tenderness along the flexor tendon sheath (64%).
Game Keepers thumb
What’s a stener lesion?
Valgus Instability in flexion vs extension indicates?
Acute vs chronic injury?
Deep space infections:
what is parona’s space?
Thenar:
Hypothenar:
Midpalmer(central):
Parona’s: connection b/t thumb and SF flexor sheaths; b/t PA and FDP conjoined tendon sheaths.
Thenar (bursa between adductor pollicis and flexor tendons)
Hypothenar
aaos Flexor tenosynovitis of the thumb flexor tendon sheath can spread proximally and form an abscess within the thenar space of the palm. The flexor pollicis longus tendon does not pass through the central space of the palm or the hypothenar space of the palm. The flexor pollicis longus tendon does pass through the carpal tunnel, but this is not a palmar space. The three palmar spaces include the hypothenar space, the thenar space, and the central space. The posterior adductor space would likely only be involved secondarily after spread from a thenar space infection.
Hand infection
Collar button abcess: where is it and tx?
abscess in web space b/t fingers, need volar and dorsal incisions for thorough I&D
Nail Bed injuries
Subungual hematoma tx?
Dermabond results?
complications?
- drain hematoma by perforation if less than 50%
- RCT has demonstrated quicker repair time using 2-octylcyanoacrylate (Dermabond) instead of suture with comparable cosmetic and functional result
- complications:
* hook nail: caused by advancement of matrix to obtain coverage without adequate bony support. Tx:** remove nail and trim matrix to level of bone**
* split nail: scarring of matrix following injury to nail bed, tx: excise scar tissue and replace nail matrix.
Seymour fracture
nailbed injury and physeal plate of distal phalanx in peds.
Imblanace: extensor tendon inserts on the epiphysis of distal phalanx and flexor tendon inserts on the metaphysis
subluxated nail plate & interposition of nail matrix blocks anatomic reduction
Acute (less than 24 hrs): close reduction + abx ok (if reduction stable)
If open injury: open reduction, and pinnin across DIP jt and nailbed repair. fewer complications than closed mgmt.
Hyperflexion of digit will permit removal of interposed soft tissue from fracture site
Pressure injuries
PSI of ? are capable of penetrating skin, most industrial pressures are?
Nonop vs Op?
Prognostic variables?
100 PSI, industrial water jet pressures are 8,000 to 12,000 PSI
Nonop: higher complications, 50% treated non op go on to require surgery
Tx: I&D, foreign body removal and broad spectrum I&D
Time to treatment, force of injection, volume injected, composition of material
industrial solvents & oil based paints cause more soft tissue necrosis
grease, latex, chloroflourocarbon & water based paints are less destructive
aaos High-pressure injection injuries are associated with a high risk of amputation. The risk of amputation is highest with organic solvents. The presence of infection and the use of steroids do not impact the amputation rate. Amputation risk is lower if surgical debridement is performed within 6 hours. Elevation and observation would delay necessary care. Neutralizing agents may be used in specific situations, such as hydrofluoric acid exposure or chemotherapeutic agent extravasation, but in high pressure paint thinner injection, the best outcome is achieved through early surgical lavage. This type of injury represents a difficult problem in hand surgery. The factors that most determine outcome after high-pressure injection injuries into the fingertip include: involvement of the tendon sheath, extent of proximal spread of the injected substance, pressure setting, and delay to surgical treatment. The other factor that likely is most important is the type of substance injected. Water and latex-based paints are least destructive. Grease and chlorofluorocarbon-based substances are intermediate, but aggressive surgical debridement can restore reasonable function. Oil-based paints are highly inflammatory and can cause such chronic inflammation such that amputation may be the only reasonable treatment option despite early aggressive surgical treatment.
Frostbite
when to debride?
prevention?
tx?
delay debridement until demarcation
footwear thermal isulation is most important factor for protection
Tx: initial resuscitation with warm IV fluids, tetanus prophylaxis, NSAIDS, silver sulfadiazine ointment or topical antibiotics to open wounds, rapid rewarming
tPA within 24 hrs reduces rate of digital amputations.
escharotomy if circumfrentially constrictive
debrided and clear blisters + aloe vera reduces prostaglandin F2 and thromboxane B2
drain/aspirate hemorrhagic blisters but leave intact, prevents dessication of underlying dermis
Fingertip ampuations and flaps
Goals of treatment?
Healing by secondary intention for?
Revision amp (primary closure)?
Full thickness skin grafting from hypothenar region?
Flap reconstruction?
Goals: sensate tip, durable tip, bone support for nail growth
Healing by secondary intention:
* adults & children w/ non bone or tendon exposed < 2cm of skin
* children with exposed bone
Techniques:
Secondary intension: complete healing takes 3-5 weeks
Revision amp: ablate remaining nail matrix, disarticulate DIP jt if flexor/extensor tendon insertions can’t be preserved, transect remaining tendons as proximal as possible, palmer skin brought over bone and sutured dorsally.
FTSG from hypothenar region:
STSG not useful b/c contractile, tender, less durable
VY advancement flap?
Thenar flap?
cross-finger flap?
Reverse cross finger flap?
Moberg volar advancement?
First dorsal metacarpal artery flap?
- V-Y flap is useful for extending dorsal skin to cover a transverse or dorsally angulated fingertip injury. They are typically used for finger tip amputations which have more dorsal soft tissue loss than palmar loss. Nail bed removal is important to prevent a subsequent hook nail deformity.
- Cross finger flaps are indicated in patients > 30 years of age when the lesion is a volar oblique finger tip lacerations or a volar proximal finger lesions. The advantage is it leads to less stiffness.
- Moberg advancement flaps are indicated for volar thumb defects
- first dorsal metacarpal artery (Kite) flap is the most appropriate flap for defects of the dorsal aspect of the thumb.
first dorsal metacarpal artery (FDMA) arises from the radial artery at the anatomical snuff box.
what type of flap for each region?
what type of injury causes the biggest risk for digital neuroma formation?
Avulsion-type injuries have been shown to pose the most significant risk of digital neuroma formation compared to other mechanisms of injury.
reverse cross finger flap wound best cover?
dorsal fingertip wound involving the eponychial fold or doral PIPJ wound
The RXFF is indicated for reconstruction of: (1) eponychial skinfold and coverage of an exposed extensor tendon near the IP joint, (2) sterile matrix nailbed defects with exposed distal phalanx, (3) contused, repaired, or grafted extensor tendon denuded of paratenon, (4) boutonniere deformity with poor-quality skin over the PIP joint after burn/avulsion injury, (5) complete avulsion of the nailbed, germinal matrix, and surrounding skin of digits
Z plasty for scar contracture lenthening: 40 degree limbs? 60 degrees lengthens by?
50% and 75% lengthening
Replant
Indications and contraindications to replant?
Yes: thumb, multiple digits, distal to FDS insertion (relative) (zone1), pediatric
No: ribbon sign,
hand proximal to carpal: ischemia time > 6hrs warm, 12 hrs cold
digits: ischemia time >12hrs warm, >24hrs cold
Single digit amputations proximal to the insertion of the flexor digitorum superficialis (FDS), in generally have poor function and severe stiffness following replantation. Replantation between the FDS insertion and the distal palmar crease (zone 2 flexor tendon injuries) has historically led to poor results due to stiffness at the proximal interphalangeal joint, decreased sensation in the finger, and tendon adhesions between the FDP and slips of the FDS
replant
Indications for revision amp?
degloving (need to repair atleast 2 veins), boneinjury w/ neurocascular damage, injury proximal to FDS insetion/PIP
replant
if ray resection vs MCP level amp:
revision amp w/ wider 1st webspace & thus avoids priminent 1st MC head impingement & improve dexterity; revision amp w/ higher satisfaction scores. Some thought that preservation of palmer width with MCP level amp improves grip strength & thus should be done for heavy laborers
replant
order of structures for replant
BEFANV
bones
extensors
flexors
arteries
nerves
veins
replant structure by structure rather than digit by digit
replant
thrombosis at risk post op timing and tx?
arterial (within 12hrs) remove bandage place hand in dependent position, heparin, stellate ganglion block
venous thrombosis after first 12 hrs: elevate hand, leech
replant
leech therapy: risk of ?? ppx with
leech therapy helps with venous congestion,
risk for aeromonas hydrophilla (gram neg rod) infection, ppx with cipro (inhibits DNA gyrase) or tmp-smx (if CKD or FQ resistance)
leeches release hirudin, anticoagulant, heparin soaked pledgets if no leeches.
replant
what causes reperfusion injury?
what drug for reperfusion injury?
mechanism: ischemia induced hypoxanthine conversion to xanthine
allopurinol: inhibits xanthine oxidase= decrease xanthine. Thought to be responsible for reperfusion
distal phalanx amputation what’s a risk if incomplete ablation of germinal matrix?
nail inclusion cyst
Arm Flaps
Lateral arm flap: blood supply?
Lat dorsi myocutaneous flap?
Lateral arm flap: for lateral arm defects, posterior radial collateral
Lat dorsi: thoracodoral artery, branch of subscapular artery, perforators off profunda brachii
free antegrade lateral arm flap (LAF) for soft tissue coverage of the forearm. The flap is based on 3-5 septocutaneous perforators from the posterior radial collateral artery (PRCA), a branch of the profunda brachii. During flap elevation, posterior antebrachial cutaneous nerve is often sacrificed, leading to hypoesthesia of the forearm. During flap elevation, care must be taken to protect the radial nerve, which runs nearby, to prevent transient radial nerve palsy. The flap can also be raised as an osteofasciocutaneous flap (with a vascularized humerus block), as a sensate flap (with posterior brachial cutaneous nerve), musculofasciocutaneous flap (with triceps), or just a fascial flap.
Leg muscle flaps: use and blood supply
Medial Gastroc
Lateral gastroc
Soleus
Gracilis
Free Flap
Groin flap
Bone flaps: use and blood supply
Free iliac
Free fibula
Vascular bone graft radius
index metacarpal
free tissue transfer within ?? for sever trauma?
Free tissue transfer within7 daysfor severe trauma in the upper extremity has been shown to decrease complication rates
groin flap artery and nerve
groin flaps are based on the superficial circumflex iliac artery and place the lateral femoral cutaneous nerve at risk.
Peripheral Nerve Injury and Repair
after injury, first/last to be lost and to recover?
Maximum gap can be bridged by nerve collagen conduit?
What is a nerve conduit made out of?
Best nerve for recover? Worst nerve for recovery?
Median Nerve Lac may require?
indications for nerve autograft?
Peripheral Nerve Injuries
Most important prognostic factor? good prognosis, bad?
- age
- Good: stretch injuries or clean wounds, after direct surgical repair
- Poor: crush or blast, infection, scarred wound, delayed surgical repair
Peripheral Nerve Injuries
Seddon and Sunderland classification:
Neuropraxia?
Axonotmesis?
Neurotmesis?
Neuropraxia: Sunderland 1st degree, “focal nerve compression”
* reversible conduction block w/o wallerian degeneration
* focal temporat demyelination of axon (axon remains intact)
* NC vel slowing or complete conduction block
* no fibrillation potentials
Axonotmesis: Sunderland 2nd-4th degree
- incomplete nerve injury
- Disruption of axons & myelin sheath disruption leading to focal conduction block
- wallerian degen distal to injury
- variable degree of connective tissue disruption
- fibrillation and positive sharp waves on EMG
- neuroma incontinuity may develop
- prognosis: unpredictable
neurotmesis: 5th degree
complete** disruption of endoneurium** (all layers)
focal conduction block w/ wallerian degeneration
fibrillations and positive sharp waves on EMG
neuroma forms proximally
glioma forms distally.
Regeneration process after transection?
distal segment undergoes?
shwann cells?
proximal budding?
Nerve Grafting
approach?
autologous graft?
allograft?
Conduits?
create tension free repair using a graft that is atleat 10% longer than gap
Peripheral nerve repair: Best if procedure is performed ??
* No technique deemed superior.
* Gaps may be addressed with nerve conduit, decellularized nerve allograft, or autograft.
Peripheral nerve repair: Best if procedure is performed** early (less than14 days), repair is tension-free, and wound bed is clean.**
* No technique deemed superior.
* Gaps may be addressed with nerve conduit, decellularized nerve allograft, or autograft.
principles of tendon transfer
tendon transfer for radial nerve palsy?
wrist ext? Finger ext? thumb ext?
For low median nerve palsy?