Flexion tendon injuries Flashcards
How do tendons heal?
- INFLAMMATORY= 0-7days- cellular proliferation (no strength- strength due to suture !)
- FIBROBLASTIC=- 1-3 wks- fibroblastic proliferation with disorganised collagen( inital Type 3m replaced by Type 1)- strength increasing
- REMODELLING- >3 wks linear collagen organisation- will tolerate active motion
Where does FDP insert?
- Base of distal phalanx 2-5 fingers
What is FDP innervation?
- Medial part-little/ring fingers - ulna nerve C8/T1
- Ulna part- AIN - branch of median c8/T1= index/middle fingers
What is FDP action?
- Flexor of DIPJ
- Assists with PIPJ and MCPJ flexion
- Shares a common muscle belly in forearm
What is FDS insert and what is its innervation?
- Bodies of middle phalanges index- ring
- Median Nerve C7,C8,T1
What is FDS action?
- Flexes PIPJ at digits 2-5
- Flexes proximal phalanges at MCPJ
What is FPL insertion?
- Base of distal phalanx of thumb
What is FPL innervation?
- AIN- median C8/T1
what is FPL action?
- Flex phalanges of 1st digit thumb
Where is FPL located in the wrist?
- IN the carpal tunnel
- as most radial structure
What is FCR insertion?
- Base of 2nd MC
what is FCR action?
- Flexes** and **abducts wrist
What is FCR innervation?
- median nerve c6/7, closest tendon to median nerve
What is FCU insertion?
- pisiform bone
- hook of hamate
- 5th MC
What is FCU action?
- wrist flexion and adducts hand
What is FCU innervation?
- Ulnar nerve c7/8
What is the blood supply to the tendons ?
- 2 sources
- Diffusion thru synovial sheaths when tendon within the sheath-most important proximal to MCPJ
- Direct vascular supply those outside sheaths- via digital artery to long/short veniculum
What is campers chasm?
Location of the level of the proximal phalanx where FDP splits FDS in two - goes thru the middle of it!
Can you describe the zones for flexor tendon injures ?
Zones 1-5
- Zone 1- distal to FDS insertion
- Zone 2- Prox to FDS insertion to palm crease
- Zone 3- palm crease to carpal tunnel
- Zone 4- carpal tunnel zone
- Zone 5- Proximal to carpal tunnel
thumb
- Zone 1- tip to distal IPJ- FPL had no lumbricals or veneulae so can retract to palm!
- Zone 2- Over thenar eminence- can have injuried to thenar muscles and recurrent branch of median nerve
What injuries pccur at zone 1?
- Distal to FDS insertion ( distal to prox phalanx iin fingers)-
- Jersey Finger
Can you describe the classification?
NB remember worse first!!
Type 1- FDP tendon retracts to PALM!!!! disrupts vascular supply- tx with prompt surgery within 7-10 days
Type 2- FDP retracts to PIPJ- attempt repair within several wks
Type 3- Large AVULSION fracture- LIMITS retraction to level of DIPJ- attempt to repair
Type 4- osseous fragment and AVULSION of tendon from fragment- DOUBLE AVULSION- tendon goes to PALM- if tendon separated from fracture fix fracture first then tendon
What is the tx for Zone 2 flexor tendon injuries?
- Prox to FDS insertion to palm
- Unusual as FDS and FDP share same tendon sheath
- Direct repair of BOTH TENDONS
- Then EARLY ROM
- PRESERVE A2 and A4 PULLEY
- historically poor outcome ‘noman’s land’ but improved due to modern repair techniques and advancment in post op motion protocols
What is the tx for Zone 3 flexor tendon injuries?
- Palm area
- Often associated with NV injury so worse prognosis
- Direct tendon repair
What is the tx for Zone 4 flexor tendon injuries?
- Carpal tunnel area
- often complicated by post op ADHESIONS due to close to synovial sheath of carpal tunnel
- Direct tendon repair
- Transverse Carpal ligament should be repaired in a lengthened fashion
what is the tx for zone 5 flexor tendon injuries?
- Prox to carpal tunnel, wirst to forearm
- often associated with NV injury
- Direct tendon repair
What is the tenodesis effect?
- Normally wrist extension-> passive flexion MCP, PIPJ and dipj
- Need to test for each digit
- Maintaince of dipj/pipj extension with wrist extension suggests flexor tendon rupture
What are the signs and symptoms of flexor tendon rupture?
Symptoms
Loss of active flexion to DIPJ/PIPJ/MCPJ
Signs
- Malignment of finger cascade= fracture
- Assess skin integrity- tendon rupture
- Traumatic arthrotomy sites
- Test tenodesis effect= wrist extension-> flexion at MCPJ/PIPJ/DIPJ
- If flexor tendon ruptured wrist extension-> dipj/pipj held in extension
- Test Active DIPJ/PIPJ each finger
- Neurovascular exam- close proximity of flexor tendons to digital nerves
When would you not operate?
- In Partial Lacerations <60% width
- may be associated with triggering/ gap formation
What surgical tx are there?
- When laceration >60%
- Flexor tendon repair and controlled mobilization
- Flexor tendon reconstruction and intensive post op rehab= failed primary repair, surgical tenolysis required in >50% of time
What incision would you make to repair a flexor tendon?
- Bruner zigzag incision ( avoids vascular compromise)
- cross flexion creases transversely or obliquely to avoid contractures - NEVER LONGITUDINALLY
When is the ideal time for repair?
- Within 3 weeks of injury ( 2 wks ideal) longer -> tendon retracture
What is the technique for repair?
- 4 strand core suture- crucitate- using non absorbable monofilament prolene gd compatibility,retains strength
- No of suture strands that x repair more important than no of grasping loops
- linear relationship strength of repair and no of sutures crossing repair
- 4-6 strands adequate strength for early active rom
- locking loops decrease gap formation
- core sutures placed dorsally are stronger
- atruamatic handlng Circumferential
- Circumferential Epitendinous suture 6.0 prolene- improves tendon gliding , strength of repair ( adds 20%) and allows for less gap formation.Simple running suture best
- Sheath repair contraversial - thought to improve tendon nutrition through tendon sheath but clinical studies have found no diff from repair to non repair
When are flexor tendon repairs weakest? where does repair fail?
- Post op day 6 and 12
- At suture knots
What has been the best improvement of outcomes?
- Post op controlled mobilisation
- To reduce adhesions and leads to increase tendon excursion
Can you describe the principles of rehab?
what are the different types?
- Motion of repaired tendin unit leads to predominacne of intrinsic cf extrinisic tendon healing and reduce adhesions
- Passive motion protocols- low force low excursion
- Early active motion protocols- high force/high ex
- Synergistic motion regimen- low force/high excur
What are is the difference between passive motion vs early atcive motion vs synergistic protocols of rehab?
Passive motion
LOW force and low exercusion
- Klinert technique-uses a dorsal block slpint with wrist at 45o of lfexion and elxastic bands secured to nails nails adn more proximal attachment.Once IPJ are actively fully extended , recoil is elastic flexes them down passively
- Duran Protocol- uses a splint with wrist in flexion 20o. relies on pt to alternatively passively extend the DIPJ/PIPJ with other joints of fingers flexed. aim to withdraw reapired fds/fdp away from repaired site.Pt compliance is requisite
Early Motion protocols
Moderate force and potential high extercusion
- involves the generation of light muscle forces to assist digital flexion or preform ‘place and hold’ exercises w digit
- Dorsal blocking splint used to limit wrist extension
- Although some evidence of increased tensile strength at repair site compared to passive protocols, high risk of rerupture, gap formation potential concerns
Synergestic motion
Low force high exercusion
- Passive digit flexion combined with active wrist extension, followed by active digit extension coupled with active wrist flexion
- Tendon exercusion by employing wrist motion is greater than that provided in an extension blocking splint
How about children post op?
- Initlally in cast with the wrist and mcl positioned in flexion and ipj in extension- edinburgh position
Can you describe the technique for reconstruction surgery?
- Normally 2 stage
- silcone impant inserted -> favourable tendon bed
- Wait 3-4 months then pass a biological tendon thru the tendon sheath created after removeal of the silicone rod.
- single stage preformed if flexor sheath prestene and from of joints
- use Palmaris longus, plantaris ( extrasynovial grafts),2nd toe FDL ( intrasynovial grafts)
- Intrasynovial grafts less tissue necrosis, better preservation of gliding.
- Pulleys to be constructed proximal and distal to joint
What are the indications for 2 stage flexor tendon reconstruction?
- Require supply skin,adequate vascularity, passive from adjacent joints, sensate digit
- use in crush injuries of adj soft tissues, delayed or failed primary repair
what are the complications of flexor tendon injuries?
- Tension adhesions
- Rerupture-5-15%:around 7-10 days post op if <1cm scar, excise and direct repair but if scar>1cm need tendon reconstruction
- Joint contracture-17 %
- Swann neck deformity
- Trigger finger
- Lumbrical plus hand
- Quadrigia
What would be the indications for tenolysis?
- Localised tendon adhesions with minimal to no joint contracture and full passive rom
- Preform at .3 months to wait for soft tissue stabilisation and full passive rom of joints
- Preserve A2/A4 pulley
- follow with intensive physio
