TENDONS - flexor, extensor and tendon transfer Flashcards Preview

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Flashcards in TENDONS - flexor, extensor and tendon transfer Deck (77):
1

List principles of tendon transfer

  1. Supple joints, full pROM
  2. stable soft tissue bed
  3. Expendable donor
  4. Adequate excursion
  5. Adequate force/motor function
  6. Synnergistic
  7. Straight line of pull
  8. 1 function per tendon transfer

2

List the contents of dorsal extensor compartments and pathologies specific to each compartment

  1. EPB, APL: de Quervain's
  2. ECRB, ECRL: intersection syndrome (w/ 1st)
  3. EPL: traumatic/attrition rupture s/p non-operative mngmt distal radius #
  4. EIP, EDC: extensor tenosynovitis
  5. EDM: Vaughn-Jackson syndrome (ulnar to radial attrition rupture in RA)
  6. ECU: snapping/subluxation

3

describe common anatomic variations of 1st dorsal extensor compartment

  • vertical septum creating 2 subcompartments
  • multiple slips of APL

4

why can a person independently extend the index finger after EIP tendon transfer?

  1. lack of junctura teninae between D2 and D3
  2. individually innervated independent muscle bellies

5

are EIP and EDM ULNAR OR RADIAL to respective EDC tendon?

  • ulnar

6

what is a seymour fracture and what is your treatment plan?

  • a seymour fracture is a trans-epiphyseal fracture of the distal phalanx in a skeletally immature patient
  • closed fractures have intact nail plate (and underlying nail bed)
  • open fractures often present w subluxation of nail plate from under the perionychium w associated nail bed (germinal, sterile) injury
  • treatment closed:
    • splint x 6 wks, then night/activity x 6 wks
  • treatment open - need to recognize bc "like" an intra-articular fracture
    • remove nail plate
    • copiously irrigate fracture
    • repair nail bed
    • replace nail plate
    • splint x 6 wks, then night/activity x 6 wks vs. k-wire & splint if unstable
    • consider PO antibiotics (no evidence)

7

how would you treat a zone III BLUNT/CLOSED extensor injury?

  • blunt, no fracture
    • splint PIPJ in extension, DIP free x 3 wks, protected range of motion x 2 wks
    • if lag, unstable consider splinting whole finger vs k-wire stabilization
  • Blunt, fracture (central slip is w fracture fragment)
    • if piece large, consider screw fixation then splint vs. k-wire as above
    • if piece is small, consider excise and advance (mitek screw anchor vs. transverse wire across base of MP) then splint vs k-wire as above

8

a blunt injury to MCPJ and extensor lag

how would you differentiate between sagittal band vs central tendon injury?

  • sagittal band: can MAINTAIN extension when place passively
  • central slip, cannot maintain or initiate extension

9

for complete laceration to zone 5, what is treatment approach?

  • repair EDC - running horizontal mattress vs. core suture +/- dorsal epitendinous
  • repair sagittal band - figure of 8
  • wrist 20' ext, MCP neutral or slight hyperext, IPJ free x 3 wks; protected motion x 2 wks
  • vs. yoke splint x 3 wks, protected motion x 2 wks

10

what is the mechanism of rupture for EPL after distal radius managed closed.

  1. ischemic rupture: decrease diffusion / blood flow
  2. attrition rupture: hematoma, inflammation/synovitis, callous narrows the 3rd compartment, leads to mechanical irritation and attrition rupture

11

how would you treat a non-inflammatory rupture of EPL or EDC

  • options include address etiology and intercalary graft or tendon transfer (eip to epl; edc to edc end to side)

12

what is the suspected etiology of extrinsic extensor tightness?

  • common post-traumatic or post-operative
  • too tight repair / transfer
  • muscle or soft tissue contractures
  •  

13

what is your treatment plan for a patient with post-operative or post-traumatic extrinisc extensor tendon tightness

  • after immobilization, initiate protected motion protocol after 6 (zone 1,2), 3 (zones 3,4,5), 4 (zones 6+) weeks
  • if presenting late, then initiate static and dynamic splinting
  • progress to exercise program of assisted flexion/extension for several months (3-6) prrio to OR
  • operative interventions
    • tenolysis
    • extrinsic extensor release (excise portion of central tendon between sagittal band and prior to emergence of lateral bands/PIPJ

14

what is the etiology of intrinsic contracture?

  • trauma/burns: adhesions, ischemic contracture, nerve injury
  • inflammatory joint disease / RA / SLE: volar MCP subluxation, inflammatory adhesions
  • CP/stroke, parkinsons, encephalitis (CNS): spasticity

15

describe a treatment plan for intrinsic contracture

  • essential hand therapy, static/dynamic splinting pre-operatively
  • operative
    • excise lateral bands
    • excise ulnar lateral band and step-lengthen (vs zplasty) radial lateral band

16

what are operative interventions to address late presentation of sagittal band injury

  • first need to centralize the EDC (may need to partially release ulnar sagittal band)
  • numerous options described
    • ulnar junctura, proximally based partial slip of EDC, proximally based partial slip of ulnar sagittal band, free tendon graft - used to maintain central position of EDC - sutured to / around adjacent radial lumbrical, radial collateral ligament
  • post-op immobilize MCP & finger in extension until first post-op, then IPs free, then gentle aROM to MCP at 2-3 wks, then graduated increase activity (initial extension splint, then yoke splint)

17

discuss the patho-etiology of Boutonniere deformity

  • problem is always initiated at PIPJ
  • with injury/attenuation of the central slip leads to unopposed flexion at PIPJ
  • with time, there is volar migration of lateral bands
  • lateral bands become flexors of PIP and extenders of DIP
  • over time, oblique retinacular ligament becomes contracted and triangular ligament becomes lax, and there is loss of passive extension of PIP/passive flexion of DIP and joint contracture
  • eventually this abnormal posture imparts abnormal forces of joint surfaces, leading to degenerative arthritis

18

describe classification of boutonniere deformity

burton classification

  1. extensor lag, full passive extension (supple joint)
  2. fixed contracture, lateral band contracture
  3. fixed contracture, joint fibrosis, volar plate fibrosis/contracture
  4. with degenerative joint changes

Essential features to differentiate clinically and classify the injury to guide treatment:

acute vs. chronic (will respond to early initiation of spinting protocol / prophylaxis against worsening deformity)

supple & passively corrected joint vs. fixed contracture (will/should respond to non-operative program to rebalance extension mechanism (lateral bands); contracted joints may need preliminary surgical stage of capsulotomy);

with / without associated degenerative joint changes (consider rebalancing + joint arthroplasty vs. arthrodesis in better functional position)

19

Discuss treatment plan for early and/or supple boutonniere deformity

  • non-operative management is usually sufficient to rebalance extensor mechanism / lateral bands, and restore normal motion / more functional motion
  • 3 step program
  • stage 1: achieve full passive extension (serial splinting, dynamic casting, physio; for aptients not completely responsive, may need to consider capsulotomy as prelim operative stage)
  • stage 2: rebalance extensor apparatus: add exercises to DIPJ - active and passive flexion to lengthen lateral band, move volar
  • stage 3: maintain PIP extension: PIP extension splint alone, DIPJ free x 8 wks
    • if extensor lag recurs, then resume splinting
  • if failed, or extensor lag > 30', consider surgical intervention

20

LIST surgical options to treat chronic boutonniere

  • all patients have central slip, triagular ligament, oblique retinacular ligament tenolysis
  • Fowler terminal tenotomy (tenotomy distal to triangular ligament)
  • Central slip reconstruction
    • resection of attenuated / scarred portion and primary repair
    • central slip shortening
    • Tendon graft procedures to restore central slip
  • Lateral band rebalancing / mobilization centrally

21

what would you do for a patient with a chronic boutonniere, failed appropriate course of non-operative management, and with extensor lag of 47' but partial passive extension

 

  • ensuring that full passive ROM (extension) has been achieved - if unable to do via non-operative management, undertake preliminary stage of capsulotomy; then post-operatively re-institute 3-stage program of non-operative therapy (many patients will improve at this point to lag < 30')
  • if still extensor lag 47': long discussion with patient regarding ongoing benefit from non-operative management, risks of surgery (stiff finger with limited flexion) vs. benefits of surgery (depends on limitations w extensor lag)
  • if proceeding with surgery, my plan is:
    • extensive tenolysis
    • folwer distal tenotomy (of terminal tendon distal to triangular ligament)
      • lateral band insertion to terminal tendon preserved but tension at terminal tendon released and hyperextension released
      • proximal migration of rest of extensor apparatus increases tone at central slip
    • mobilization and dorsal centralization of lateral bands
      • effectively to act as PIP extensor like central lip
      • extension of DIPJ facilitated through intact oblique retinacular ligament to lateral bands

22

For a Swan Neck Deformity, describe the acute and chronic changes that occur to the extensor mechanism and periarticular structures

  • acute
    • volar plate laxity
    • dorsal subluxation of lateral bands
    • attenusation of transverse retinacular ligament
  • chronic
    • extensor tendon adhesions
    • contracture of lateral band
    • PIP and DIP fixed contractures
    • degenerative joint changes

23

list the potential etiologies for swan neck deformity:

  • swan neck deformity originates in pathology at or proximal to PIP or at the DIP
  • PIPJ
    • extrinsic tightness
    • intrinsic extensor tightness: CNS pathology, trauma, nerve injury, inflammatory joint disease
    • MCPJ volar subluxation: inflammatory joint disease
    • laxity of volar plate / ligamentous structures of PIPJ: injury (dislocation), inflammatory joint disease, other chronic joint effusion/synovitis
    • FDS injury / laxity or repair or transfer
  • DIPJ
    • chronic mallet
    • short MP (sequellae of MP#)

24

describe the pathophysiology of development of swan neck deformity when originating from PIP vs DIP

  • pip hyperextension
    • primary hyperextension at PIPJ from extrinsic or intrinsic tightness, MCP volar subluxation, FDS laxity/injury, laxity of volar plate/ligamentous structures @ joint
    • laxity and dorsal subluxation of lateral bands - inability to extend DIP
    • attenutation of FDP when passing over hyperextended PIP - increased flexor tone at DIP
  • dip flexion
    • disruption of the terminal tendon
    • extesnor force focussed at central slip
    • gradual weakening of volar joint structures
    • PIP hyperextends

25

describe a classification of swan neck deformity, outline the important components for decision making

  • a classification for swan neck proposed by feldon (described originally for RA)
  1. fully passively flexible PIP and DIP
  2. joints passively flexible in certain positions, given presence of intrinsic tightness
  3. fixed PIP deformity, normal articular surfaced
  4. fixed PIP deformity, abnormal / destructive articular surfaces

Important components for decision making are:

- passive flexion in all positions?

- presence of intrinsic tightness?

- fixed PIP +/- DIP contracture

- destructive joint changes

26

what are surgical options to treat swan neck deformity when problem originates at PIP or proximal?

  • MCPJ
    • intervention at this joint indicated by presence of intrinsic tightness
    • if present, then intrinsic release (often ulnar intrinsics, because there is ulnar deviation)
    • if chronic MCPJ subluxation & joint destruction, then MCPJ arthroplasty recommended
  • PIPJ - several options for flexible PIPJ in all / some positions:
    • Volar plate capsulodesis
    • FDS sling / tenodesis (distally based ulnar slip of FDS is advanced proximally to PP istelf or around A2
    • Intrinsic re-routing described by Littler - ulnar lateral band is sectioned at musc-tend jxn, re-routed volar cleland/grayson and attached to volar PP or flexor sheath
    • spiral ORL reconstruction (free tendon graft dorsal to volar through DP, spiral proximal and volar through base of MP)
  • PIPJ - when there is fixed contracture in all positions
    • PIPJ capsulotomy, joint mobilization, +/- lateral band mobilization (separation from dorsal position and ass'n w/ central slip), +/- skin release if relative insufficiency, +/- short k-wire immobilization
    • vs PIPJ capsulotomy, joint mobilization, and approaches listed above
  • DIPJ
    • do nothing (when all joints supple, rebalancing at PIP may be sufficient)
    • vs arthrodesis

27

what are the surgical options to treat swan neck deformity when problem originates w chronic mallet?

  • address the chronic mallet
  • if < 2-6 mos or if still tender at DIPJ then period of splinting may be beneficial
    • extension splint for DIP plus figure of 8 for PIP
  • fowler central slip tenotomy
  • spiral ORL reconstruction
  • advance terminal tendon

28

WHAT IS THE FUNCTION OF THE FLEXOR SHEATH?

  • nutrition via diffusion
  • tendon gliding
  • improve exurusion of flexion by prevention of bowstringing

29

List special considerations for each zone for a flexor tendon injury

  • zone 1: FDP only
    • consideration is whether there is sufficient stump for direct primary repair or if a pull-through suture over a wire is required
    • consideration is whether there is proximal retraction of FDP to palm (depending on vinculae/bone avulsion as per leddy classification)
    • should preserve or reconstruction A4 pulley
    • immobilization protocol for pull-through suture technique, otherwise passive motion
  • Zone 2:
    • consideration is that both FDP and FDS have likely been injured
    • should aim to repair both, or at least 1 slip of FDS
    • should preverse or reconstruct A2 pulley
    • early motion protocol essential to improved outcomes, early active when possible (> 4 strand repair)
  • zone 3
    • typically good tendon outcomes, but sharp injuries in this zone associated with neurovascular injury to common (or proper) digital vessels and nerves
    • early motion protocol (passive or active)
  • zone 4
    • need to explore for associated median nerve injury
    • may be adhesions through small space;
    • need to repair and step-lengthen (or z-plasty) transverse carpal ligament
    • early motion protocol (passive or active)
  • zone 5
    • often associated w other major neurovascular injury, need to explore widely
    • if at MT junction or muscle belly then repair w vicryl, figure of 8 sutures
    • immobilization protocol

30

discuss timing of repair

  • optimal timing is early repair (wihtin 2 wks)
  • no benefit of immediate over early repair
  • delayed primary repair wihtin 3-4 wks
  • secondary repair/delayed repair/reconstruction when:
    • associated extensive soft tissue injury wiht inability to cover repair immediately
    • associated devitalized or infected tissue
    • late presentation
    • rupture of previous repair

31

discuss indications for immobilization after flexor tendon repair

  • children not able to comply w therapy
  • adults not able to comply w therapy
  • associated repair of nerve injury (for 3 wks) or vessel injury (2 wks)
  • unstable associated injuries (non-rigidly fixated fractures)

32

list types of epitendinous repair and respective increase in strength

  • simple running - 10%
  • locking running - 40%
  • running horiztonal - 80%
  • silverskold  - 120%

33

discuss your management of a clean lacertation in zone 2, distal to the bifurcation of FDS

  • tetanus, workup
  • consent
  • tourniquet
  • GA if > 2 tendons or tendon + other structure
  • bruner incision incorporating laceration
  • accessing sheath through space between annular ligaments (ie cruciate)
  • identification of proximal and distal tendon ends
    • to identify/retrieve proximal, can make proximal transverse incision at a1, palm
    • wrist/mcp flexion, milking forearm, small mosquito, feeding tube
  • secure to length/tension with 27g needle
  • ensure FDP properly oriented through decussation, and both tendons wihtin sheath
  • FDP: back wall epitendintous, 4-strand locking cruciate, front wall epitendinous
  • FDS: repair both slips with 4-strand (depending on space, modified kessler + horizontal mattress)
  • ensure sufficient space within sheath
  • consider step-lengthen A2 pulley
  • reconstruct pulley acute if rquired (first choice is 1 slip of FDS)
  • irrigate
  • close
  • non-adherent dressing
  • splint: wrist 20-30' flex, MCP 70-90' flex, IPs straight

34

what is the leddy classification?

  • leddy classifcation for zone 1 flexor injuries - classically for avulsion type injuries (jersey finger)
  • 1: both vincula ruptured, FDP retracts to palm
  • 2: VLP intact, +/- small bone chip, retracts to A2
  • 3: larger volar piece of avulsed bone, held at A4
  • 4: tendon avulses from larger bone piece, retracts to palm

35

what size of stump is typicaly required to primary repair a FDP injury? if less than this, what is the repair appraoch? if met, what is the repair approach?

  • stump >=1cm = primary repair
    • > 4 strand + epitendinous will facilitate early active motion protocol; is stronger than 2 strand
  • stump < 1cm - typically need to do a pull-through approach
    • bunnell stitch with monofilament suture, around DP and through nail palte (distal to lanula), tied over bolster/button

36

in zone 2 or 3 or 4 injuries, how do you differentiate between FDS and FDP?

  • FDS round vs. FDP flat
  • FDP is longer w more distal insertion
  • FDS has chiasm/decussation
  • FDP has a lumbrical origin

37

what are ways to reconstruct the pulley system in acute or delayed fashion?

  1. non-operative: pulley ring
  2. operative
    1. slip of FDS
    2. free tendon graft
    3. free extensor retinaculum graft
    4. volar plate
    5. hunter rod

38

discuss the etiology for flexor tendon rupture. what is difference in etiology in musculotendinous rupture vs intra-teindinous rupture

  • musculotendinous (and insertional) rupture generally direct traumatic
  • whereas intrateindinous rupture either iatrogenic, inflammatory, or indirect trauma
    • iatrogenic: steroid injection
    • inflammatory: RA, inflammatory synovitis (gout)
    • indirect trauma: hook of hamate fracture (ring flexor), distal radius or carpus (although also commonly extensor)

39

compare post-op protocols after zone 1 (direct primary), 2, 3, 4 repair

  • all: dorsal blocking splint wrist 30' flx, MCP 45-70' flx, IP straight
  • immobilization
    • pediatrics, unstable injuries, unreliable repair for some reason
    • x 4 wks then initate ROM
  • early protected passive - DURAN
    • first post op visit start early controlled passive extension, passive flexion
    • to achieve differential glide - exercises include passive flx MCP, DIP w/ passive ext PIP and passive flx MCP/PIP w passive ext DIP 5-10x q 1-2hr
    • velcro volar blocking straps in between
    • at 4 wks, start active extension, at 6 wks start active flexion, at 8 wks add resistance
  • early protected passive - KLEINART
    • first post op visit start early controlled active extension, passive flexion protocol
    • splint includes volar elastics to nail plate that permits elastic band traction for active extension component; 5-10x q 1-2 hrs
    • at 4 wks dc elastic traction and add active flexion
    • at 6 wks add light resistance, block PIP
    • at 8 wks increase resistance, block DIP
  • early active range of motion
    • conditions: > 4 strand core suture + epitendinous
      • various eaROM protocols: 5-10x q 1-2 hrs - some options:
      • remove volar blocking bands for wiggle
      • remove volar blocking bands for place and hold
    • at 4 wks increase range of active motion (some wiggle protocols add place and hold here)
    • at 6 wks block PIP
    • at 8 wks increase resistance and block DIP

40

when is the flexor tendon repair the weakest?

pod 5-10

41

where do you find the plantaris tendon if harvesting for tendon graft?

  • ~ 1cm medial to midline of achilles

42

when would you consider a single stage delayed tendon reconstruction?

  • Common scenarios:
    • patient w delayed presentation or unrecognized flexor tendon injury that precludes primary repair
    • patient with delayed FDP avulsion injury presentation and tendon significantly retracts into palm
    • patient with segmental tendon loss
    • patient with zone II injury and significant segmantal tendon damage, thoguht to do better w delayed grafting
  • Necessary features:
    • good / near full passive range of motion
    • little associated scar and no trophic changes
    • stable soft tissues
    • intra-operatively with intact pulleys/sheath
    • (patients should be consented for graft + repair vs. hunter rod insertion)

43

discuss how you would undertake a 2 stage delayed tendon reconstruction in zone 2.

  • stage 1:
    • bruner incisions
    • plan is to reconstruct the FDP tendon and excise the FDS from within the sheath
    • use the FDS excised as a mechanism to reconstruct the pulley
    • divide the FDP w 1-2 cm distal stump and proximally @ lumbrical origin (in palm @ lumbrical origin for zone 1-2, otherwise distal forearm)
    • suture the hunter rod to the distal FDP
    • reconstruct the pulley using spare excised tendon (or intact FDS slip is a good size, may need to pull through a button, or suture as loop around the rod & phalanx)
    • the hunter rod should extend proximally through palm (through carpal tunnel for zone 3 & proximal)
    • close, splint, initiate passive ROM 1/52 and increase to foll activitiy at 8 wks; protect pulley reconstruction w/ buddy straps
  • stage 2:
    • 3 mos later w/ full pROM
    • harvest tendon graft
    • open hand/palm widely via bruner
    • suture distal repair first using end-to-end, or weave through remaining stump and through nail plate
    • gently suture to distal rod and pull through the reconstructed sheath to palm
    • tension set
    • pulvertaft weave to rpxoimal stump in palm to set tension  & determine excess graft
    • close, splint, passive range of motion protocol until ~ 6/52 then progressive increase
    •  

44

list complications after flexor tendon repair

  • early
    • usual: infection, delayed healing, hematoma
    • specific: tendon/pulley rupture, poor gliding
  • late
    • usual: stiffness, scar, pain, CRPS
    • specific: late rupture, bowstring, lumbrical plus (too long FDP), quadregia (too tight FDP), adhesions/poor differential gliding

45

define lumbrical plus deformity

define quadregia

  • lumbrical plus: paradoxical PIP/DIP extension with attempted flexion
    • why? FDP is too lax (or retracted), such that with attempted flexion there is actually more tension exerted on lumbrical muscle, which causes IP extension
    • treatment: hand therapy vs. re-tensioning the FDP
  • quadregia: incomplete flexion (flexion lag) of the adjacent uninjured digits with attempted flexion; injured digit achieves full flexion (occassionally with flexion deformity/extension lag)
    • why? FDP was repaired too tight (primary, secondary w graft, at transfer), and the excursion limit is reached earlier with the injured digit than the others, but because of the common muscle belly the ohter digits cannot flex further
    • treatment: hand therapy vs. re-tensioning of the FDP

46

what are principles of single-stage tendon grafting?

  • never remove an intact FDS
  • use small calibre graft
  • single graft per digit
  • repair/coaptation outside flexor sheath
  • always consent for possible 2 stage procedure

47

how do you know how to set the tension in 1 or 2 stage tendon reconstruction?

  • wrist in neutral
  • each digit is subsequently less flexed than it's ulnar neighbour

48

what is a paneva-holevich graft?

  • FDS from injured digit is used as a pedicled graft
  • injured segment excised
  • distal segment sutured (or weaved) to proximal segment /end of FDP
  • @ second stage release the FDS at musculotendinous junction; this proximal portion becomes the distal portion of the tendon graft that is fed through the pulley system (pulled through with the rod)

49

what is the purpose of tendon transfer?

  • to transfer a functioning MT unit to a non-functioning nerve-muscle-tendon unit, to restore a lost action or function

50

List indications for tendon transfer

  • After a peripheral nerve injury that is:
    • presenting long duration from injury plus/or
    • too proximal for re-innervation (long distance for reinnervation), no proximal stump
    • failed primary repair or nerve transfer
  • Traumatic/iatrogenic (s/p cancer extirpation) loss of musculotendinous unit
  • CNS conditions (ex: CP, tetraplegia/spinal cord)
  • Tendon rupture
  • Less common: polio, leprosy

51

What are the principles of tendon transfer?

  • DONOR PRINCIPLES (EE, SSSS)
    • Expendable donor
    • Ecursion similar, and/or augmented via tenodesis affect
    • Synergistic action
    • Strength/power available, anticipate possible MRC downgrade x 1
    • Straight line of pull (or < 1 pulley)
    • Single function per transfer
  • RECIPIENT PRINCIPLES / PRINCIPLE PRE-REQUISITES (SSSP)
    • Stable soft tissue and skeleton (achieved at initial procedures)
    • Supple joints at maximal ROM (achieved / maintained via PT / splinting program)
    • Sensation intact to hand (or undertaken at preliminary procedure)
    • Patient is motivated and compliant for recovery & rehab

52

What are the relevant biomechanical principles emphasized for tendon transfer?

  • Muscle-tendon unit excursion
    • for muscles with shorter excursions, can augment using tenodesis
  • Muscle-tendon unit force-generating capacity
    • proportional to x-sectional area of muscle belly
    • also oriented along line of pull
  • Moment arm
    • distance line of action to axis of rotation
    • long moment arm is greater ROM at expense of strength, vice versa
  • Tension
    • optimal resting tension to achieve optimal power

53

what is the optimal timing for tendon transfer?

  • most people follow late timing for tendon transfer, usually ~ 9-12 mos s/p injury
    • why? to allow for clarification of extent of nerve regeneration
    • sometimes patients show up at this time due to management of other distracting injuries
    • allows for optimization of pROM, skeletal and soft tissue stability, +/- peripheral nerve transfers
  • Burkhalter espoused benefits of early tendon transfer for those injuries where nerve regeneration is unlikely
    • some also consider internal splint or "babysitter" analogue while waiting for regeneration - end to side PT to ECRB in radial nerve injury for example

54

what are the complications of tendon transfer?

  • general: bleeding/hematoma, infection, delayed wound healing, large scars, skin loss, stiffness, CRPS
  • specific
    • tendon adhesion, early/late tendon rupture, tendon laxity, incorrect setting of tension
    • secondary deformities (ex: swan neck)
    • donor site morbidity - decrease strength, ROM, functional deficit

55

Compare tendon transfer to nerve transfer for goals, timing, advantages, disadvantages and contraindications

  • tendon transfer
    • goals: use a functioning MT unit to restore a non-funcitonal NMT unit
    • timing: usually late, but effective at any timing if pre-requistes are met
    • advantages: reliable, fast recovery and return of function (after initial short period of immobilization)
    • Disadvantages: extensive dissection through ZOI, ~ 3-4 wks of post-op immobliation with longer duration of splinting and retraining, ptoential for adhesions, potential to disrupt MT unit balance, potential to downgrade strength by 1 MRC level
    • contra-indications: pre-requisites not met, demonstrated non-compliant pt
  • nerve transfer
    • goals: restore a lost function(s) by transfering a functional (but less important) nerve to a non-functional nerve
    • timing: within 9-12 mos of injury so there is not motor endplate atrophy
    • advantages: motor and sensory recovery, can achieve > 1 fxn per transfer, avoid dissection in ZOI, no disruption to natural MT unit balance or axis of action
    • disadvantages: longer time to notice benefit and for full recovery, ptoential for incomplete/less reliable recovery, motor re-education
    • contra-indications: equivalent/superior fxn'l outcome can be achieved in shorter peirord of time; prolonged time from injury

56

what are the functions lost between low and high median nerve injury?

  • low
    • clinically notable - thumb function: opposition, abduction, MCP flexion
    • clinically not notable - lumbrical fxn to d2/d3 - I/O tend to compensate
  • high
    • thumb opposition/abduction and IP flexion
    • d2/3 finger flexion at PIP and DIP (loss FDS/FDP)
    • weaker grip to D4.5 2' lsos of FDS
    • not clinically notable often is forearm pronation

57

list tendon transfer operations to restore thumb thenar muscle function, compare the advantages and disadvantages of each approach

  1. EIP to AbdPB transfer - preferred approach in adult w low median n injury (RMB)
    1. advantages: can be utilized in context of high median n or combined med/ulnar n injuries; dissection outside ZOI; reliable and good axis for pull; no loss of grip
    2. disadvantages:
  2. Camitz - PL to AbdPB - preferred approach w chronic RMB denervation when done at the time of CTR
    1. advantages: similar (just extended) incision for access, simple, no donor morbidity
    2. distadvantages: more of a flexion force, weak, PL absent 20%, not for trauma
  3. ADM / Huber transfer to AbdPB - preferred approach in pediatrics
    1. advantages - good line of pull, restores thenar bulk, strong, synergisitc
    2. disadvantages - in adult may not reach w/o graft, tenuous dissection near NV pedicle, long scar & loss of hypothenar fullness
  4. FDSring to AbdPB
    1. divide at base of finger; put through a pulley developed using distally based 1/2 loop of FCU
    2. advantages: simple, good direction pull, ample tendon, strong
    3. disadvantages: not for high med or combined med/ulnar n injury, dissection accross palm / ZOI, risk of swan neck deformity, could get adhesions through FCU pulley

58

what are tendon transfer options in high median nerve injury?

besides tendon transfer, what are other surgical options?

  • opponensplasty - as previously described; use EIP (or rarely ADM)
  • finger flexion - d2/3:
    • end-to-side to D4/5
    • ECRL to D2/3 end-to-end; strong (passed through intermetacarpal space; requires interpositional tendon grafts)
  • thumb IP flexion
    • BR to FPL (need to mobilize off insertion & proximally)
    • ECRL if not being used for finger flexion
  • could do nerve transfer, but would not restore finger flexion or thumb opposition
    • supinator branch or BR branch of radial nerve to AIN
    • ECRB branch to PT branch

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what is the post-op protocol after opponensplasty?

what is the post-op protocol if doing tendon transfers for high median nerve injury?

  • opponensplasty
    • 4 wks – Thumb spica splint/cast with thumb in opposition.Wrist slightly flexed for FDS or PL transfers, and slightly extended for EIP or ADM transfers
    • 4-8 wks – Long opponens splint
    • >8 wks – Progressive strengthening & stretching
  • opponensplasty, thumb FPL and finger flexor restoration
    • 4 wks – sugar tong splint with elbow flexed 90˚, wrist flexed 20˚, full thumb abduction, DEBS for fingers.Passive digital flexion & active extension initiated within the splint
    • 4-6 wks – Place & hold exercises for digits.Full elbow ROM
    • 6 wks – Active wrist extension & tenodesis exercises, then gradual progressive strengthening

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what is the Bouvier test? what is it testing, and what does the result imply?

  • test on physical exam that tests the laxity/integrity of the extensor expansion and central slip in patients with ulnar nerve injury and claw deformity
  • you passively counteract the hyperextension by brining MCPJ into neutral or slight flexion
  • then ask patient to extend PIP/IPJs
    • if patient can extend finger, extensor expansion intact, considered positive, static procedures to correct MCP hyperextension will work
    • if patient cannot extend finger there has been secondary biomechanical change to extensor expansions, and a dynamic procedure that will correct for hyperextension but also integrate MCP and IPJ motion is required

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what are procedures that can address thumb/key pinch in low ulnar nerve injury?

  • some patients may not perceive this dysfunction d/t compensation by FPL, therefore only reconstruct if symptomatic
  • BR or ECRL (plus tendon graft) or FDSring (no tendon graft rquired, not in high ulnar n) to AddP
  • consider transfer accessory slip of APL to first dorsal interosseous for index abduction to augement the pinch

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list static options to correct claw deformity

which one would you choose and why?

  • fasciodermodesis
  • bone block
  • zancolli mcpj volar plate capsulodesis (release a1 pulley, advance volar plate) - choose this because reliable, works well, easy, allows for combination w dynamic procedures later
  • Brunelli flexor A1/A2 partial pulley release - bowstring of flexor tendons causes flxn of MCP
  • Static tenodesis w tendon graft from DTMC lig to lateral band
  • Fowler dynamic tenodesis (often in static bc relies on tenodesis effect and only acts on MCP)
    • tendon grafts from dorsal extensor retinaculum, through lumbrical canal, volar to DTMC ligament, to lateral bands

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describe dynamic procedures to address claw deformity

when would you choose a dynamic procedure

which procedure woudl you choose

  • dynamic procedures when brunelli test reveals inability to extend IP when MCP hyperextension is passively corrected (ie negative test)
  • superficialis transfers
    • either use FDS to long or ring, split into 4 or use 1/2 slip of each digits FDS
    • insert either into:
      • loop around A1 or A2 (or both) pullies - Zancolli lasso
      • proximal phalanx Burkhalter
      • Radial sagittal band (Litter modification of stiles-bunelli)
  • ECRL (or ECRB, or FCR) + tendon graft, pass through intermetacarpal space/lumbricals, volar to DTMC ligament, insert onto radial lateral band (or PP or A2) of either D4/5 or D2-5
    • I would choose this option because this is what i've seen and done
    • it is reliable, less risk of 2' swan neck deformity, and provides a stronger grip/motion than FDS options
    • disadvantages include stretching of grafts

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what is the post op protocol after procedures to address claw?

·   Protocol for correction of claw deformity

o   maintain MP flexion and IP extension during healing

o   Active ROM initiated at 3wks within the limits of a dorsal extension block splint

o   by 12wks unrestricted activity allowed

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List procedures available for reconstruction of low radial nerve palsy

which operation would you choose and why?

  1. FCR transfer (Brand) - my choice
    1. PT to ECRB
    2. FCR to EDC
    3. PL to EPL
    4. Why? because the primary wirst flexor is FCU, and there are fewer ulnar deviators than radial deviators, so post-op positioning of wrist more likely to remain in neutral. Also the harvest of FCR is thought to be less extensive dissection. Also because this is what I've seen in my training. Also because FCR has a longer thendon than FCU and because PL is expendable when present.
  2. FCU transfer - JONES
    1. PT TO ECRB
    2. FCU TO EDC
    3. PL TO EPL
    4. has similar advantages as Brand, but FCU tendon is shorter and wrist tends to radially deviate and dissection to harvest FCU may be more extensive (as least closer to NV bundle)
  3. Boye's transfer
    1. PT TO ECRB
    2. FDS ring to EIP/EPL
    3. FDS long to EDC
    4. FCR to APL & EPB
    5. I would choose this if the patient does not have an PL. However it is technically more demanding and risks swan neck of long/ring w FDS harvest and decreases the grip potentially. However it provides the greatest independent motion of index and thumb. Lastly, the digit flexor to digit extensor is non-synergistic.

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what will do you post-op with a patient after tendon transfers for radial nerve palsy?

·   above elbow cast with elbow at 90 degrees, forearm pronated, wrist extended at 30 degrees, thumb spika

·   mobilize isolated joints at 4 weeks

·   ROM advanced to gentle pROM at 6 wks

·   Strengthening at 8 wks, full activity at 12 weeks

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what are some of the complex issues that arise when considering tendon transfer for a combined nerve injury?

  • usually injury is more extensive, involving greater soft tissue, skeletal and sometimes vascular injuries
  • usually the zone of injury is greater, with a largely scarred wound/operative bed
  • there can be associated extensive sensory / proprioceptive abnormalities
  • there are fewer donors available, and this can make the risk of donor morbidity and downgrading residual fxn greater

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patient with volar wrist laceration

what operations would you offer for low median/ ulnar nerve injury at 6 months since injury, repaired but no electrophysiologic evidence of renervation, where the extrinsic wrist flexors are intact and functioning (let's say s/p previous successful repair). a claw is beginning to develop

would this be different if it was 24 mnths later?

  • ensure functional recovery is not occuring following clinical and electrodiagnostic evidence; specifically identify whether the AIN was injured in original injury
  • optimize passive ROM pre-operatively
  • consent the patient for:
    • possible tenolysis (presumed previous tendon repairs)
    • possible AIN to DMB nerve transfer if available vs. consider static procedure (zancolli volar plate capsulodesis) for claw
    • possible excision of neuroma, interpositional nerve graft to median nerve (use sural nerve)
    • alternative: avoid nerve transfers and grafting, see approach below.
  • if at 24 months, only slightly different approach
    • possible tenolysis
    • possible tendon transfer for thumb opposition (use EIP in this situation)

    • possible BR to first dorsal interosseous to facilitate key pinch

    • ECRL + free tendon graft (plantaris is outside zone of injury) to radial lateral band for claw, at 24 months likely will have lost integrity of extensor apparatus (test pre-op)

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what would you consider for late presentation of high median/ulnar nerve injury, in patient that has stayed w/ PT and has full pROM and stable skeleton/soft tissue

  • outcomes will be compromised when sensation to hand is absent; may need to combine w sensory nerve transfer or do this as a preliminary surgery
  • consider wrist fusion to allow for harvest of both wrist extensors
  • key pinch: ECRB to adductor or BR to FDI
  • thumb opposition: EIP opponensplasty
  • finger flexion: ECRL (only if wrist fused or ECRB intact)
  • anti-claw: zancolli static volar plate procedure for claw

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what would you offer a patient with high ulnar & radial n injury?

  • PT to ECRB for wrist extension
  • FDS-long to EDC & EIP for finger/thumb extension (not independent)
  • FDP4/5 end-to-side to FDP long

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when considering tendon transfer in brachial plexopathy, what are specific goals to that context?

  • shoulder stability
  • elbow flexion and extension
  • wrist motion preserved so that tenodesis effect can be utilized for hand function
  • restoration of active control of hand function

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what are options to improve should motion and stability in context of brachial plexus injury, presenting late and/or after suboptimal results with nerve repair/transfer

  • trapezius transfer to deltoid tuberosity of humerus will improve shoulder abduction
    • also consider levator scapula
  • transfer of LD and teres major from medial/intertubercular groove to posterolateral humerus to improve external rotation (L'Espiscopo procedure)
  • salvage to restore stability and reduce pain is glenohumeral fusion

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what are delayed procedures to help improve elbow flexion?

  • Steindler flexoroplasty - advancement of flexor-pronator wad to a more proximal (and lateral) origin; tends to cause tight pronation
  • Pec major transfer of sternocostal head (maintaining insertion on intertubercular groove of proximal humerus) to biceps tendon; require stable shoulder; signifciant chest wall deformity
  • transfer latisimus origin into biceps tendon - if normal pre-op fxn this may be transfer of choice, however, innervation is C5-7 - same as MCN
  • triceps to biceps transfer; downside is downgrading elbow extension, which is bad for crutches or wheel chair
  • always consider free functional muscle transfer; could use intra-plexal or extra-plexal n (more common, IX or intercostal)

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what procedures can be used to enhance elbow extension 24 months after injury?

  • latisimus transfer - inertion from anterior humerus to triceps tendon
  • deltoid advancement to triceps tendon

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what is a primary difference between a tetraplegic/central spinal cord injury and a peripheral nerve injury like brachial plexopathy

  • in tetraplegia the injury is to the CNS not PNS; therefore distal to the level of the injury, the nerves are all still intact and stimulable, just not functioning
  • therefore there is no time limit for nerve transfer, because the motor end plates will not denervate

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what is the hierarchy of goals for tetraplegia?

  • shoulder stability
  • active elbow extension
  • wrist extension
  • key pinch
  • grasp
  • release
  • intrinsic function

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