TENDONS - flexor, extensor and tendon transfer Flashcards
List principles of tendon transfer
- Supple joints, full pROM
- stable soft tissue bed
- Expendable donor
- Adequate excursion
- Adequate force/motor function
- Synnergistic
- Straight line of pull
- 1 function per tendon transfer
List the contents of dorsal extensor compartments and pathologies specific to each compartment
- EPB, APL: de Quervain’s
- ECRB, ECRL: intersection syndrome (w/ 1st)
- EPL: traumatic/attrition rupture s/p non-operative mngmt distal radius #
- EIP, EDC: extensor tenosynovitis
- EDM: Vaughn-Jackson syndrome (ulnar to radial attrition rupture in RA)
- ECU: snapping/subluxation
describe common anatomic variations of 1st dorsal extensor compartment
- vertical septum creating 2 subcompartments
- multiple slips of APL
why can a person independently extend the index finger after EIP tendon transfer?
- lack of junctura teninae between D2 and D3
- individually innervated independent muscle bellies
are EIP and EDM ULNAR OR RADIAL to respective EDC tendon?
- ulnar
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)
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
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
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
what is the mechanism of rupture for EPL after distal radius managed closed.
- ischemic rupture: decrease diffusion / blood flow
- attrition rupture: hematoma, inflammation/synovitis, callous narrows the 3rd compartment, leads to mechanical irritation and attrition rupture
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)
what is the suspected etiology of extrinsic extensor tightness?
- common post-traumatic or post-operative
- too tight repair / transfer
- muscle or soft tissue contractures
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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
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
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
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)
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
describe classification of boutonniere deformity
burton classification
- extensor lag, full passive extension (supple joint)
- fixed contracture, lateral band contracture
- fixed contracture, joint fibrosis, volar plate fibrosis/contracture
- 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)
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
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
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
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
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#)
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
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)
- fully passively flexible PIP and DIP
- joints passively flexible in certain positions, given presence of intrinsic tightness
- fixed PIP deformity, normal articular surfaced
- 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
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
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
WHAT IS THE FUNCTION OF THE FLEXOR SHEATH?
- nutrition via diffusion
- tendon gliding
- improve exurusion of flexion by prevention of bowstringing
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
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