Flexor Tendon Injuries Flashcards
Blood supply
2 sources exist
- diffusion through synovial sheaths
- direct vascular perfusion
Classification
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Presentation
- observe resting posture of the hand and assess the digital cascade
- evidence of malalignment or malrotation may indicate an underlying fracture
- assess skin integrity to help localize potential sites of tendon injury
- look for evidence of traumatic arthrotomy
Nonoperative
wound care and early range of motion
- indications
- partial lacerations < 60% of tendon width
- outcomes
- may be associated with gap formation or triggering
Operative
- Flexor tendon repair controlled mobilization
- Wide-awake flexor tendon repair
- Flexor tendon reconstruction and intensive postoperative rehabilitation
- FDS4 transfer to thumb
Flexor tendon repair controlled mobilization
indications
Flexor tendon repair controlled mobilization
fundamentals of repair
fundamentals of repair
- easy placement of sutures in the tendon
- secure suture knots
- smooth juncture of the tendon ends
- minimal gapping at the repair site
- minimal interference with tendon vascularity
- sufficient strength throughout healing to permit application of early motion stress to the tendon
timing of repair
perform repair within three weeks of injury (2 weeks is ideal)
- delayed treatment leads to difficulty due to tendon retraction
approach
- incisions should always cross flexion creases transversely or obliquely to avoid contractures (never longitudinal)
- meticulous atraumatic tendon handling minimizes adhesions
Technique depends on
- core sutures
- circumferential epitendinous suture
- sheath repair
- pulley management
- FDS repair
core sutures
- # of suture strands that cross the repair site is more important than the number of grasping loops
- high-caliber suture material increases strength and stiffness and decreases gap formation
- locking-loops decrease gap formation
- ideal suture purchase is 10mm from cut edge
- core sutures placed dorsally are stronger
circumferential epitendinous suture
- improves tendon gliding by reducing the cross-sectional area
- improves strength of repair (adds 20% to tensile strength)
- allows for less gap formation (first step in repair failure)
- simple running suture is recommended
- produces less gliding resistance than other techniques
sheath repair
- theoretically improves tendon nutrition through synovial pathway
- controversia
- clinical studies show no difference with or without sheath repair
- most surgeons will repair if it is easy to do
pulley management
- historically believef to be critical to preserve A2 and A4 pulleys in digits and oblique pulley in thumb
- recent biomechanical studies have shown that 25% of A2 and 100% of A4 can be incised with little resulting functional deficit
FDS repair
- in zone 2 injuries, repair of one slip alone improves gliding
- compared to repair of both slips
outcomes
- repair failure
- tendon repairs are weakest between postoperative day 6 and 12
- repair usually fails at suture knots
- repair site gaps > 3mm are associated with an increased risk of repair failure
- adhesion formation
- increased risk with zone 2 injuries
Wide-awake flexor tendon repair
- hand surgery performed under local anesthesia only without a tourniquet, alsocalled “Wide Awake Local Anesthesia No Tourniquet” (WALANT
- performed under tumescent local anesthesia using lidocaine with epinephrine
local anesthesia in Wide-awake flexor tendon repair
- usually epinephrine 1:100,000 and 7mg/kg lidocaine
- from 1:400,000 to 1:1000 is safe
- if < 50cc is needed
- 1% lidocaine with 1:100,000 epi for a 70kg person
- if 50-100cc is needed
- dilute with saline (50:50) to get 0.5% lidocaine, 1:200,000 epi
- if 100-200cc is needed for large fields (tendon transfer, spaghetti wrist)
- dilute with 150cc saline to get 0.25% lidocaine and 1:400,000 epi
- for longer surgery > 2 hours
- add 10cc of 0.5% bupivacaine with 1:200,000 epi
location where we can use the Wide-awake flexor tendon repair
- proximal and middle phalanges, use 2ml
- distal phalanx, use 1ml
- palm, use 10-15ml
Advantages of Wide-awake flexor tendon repair
- allows intraoperative assessment for repair gaps by getting awake patient to actively flex digit
- reduces need for postop tenolysis by allowing intraoperative assessment of whether repair will fit through pulleys
- allows on-the-spot debulking of bunched repairs
- allows division of A4 pulley and venting (partial division) of A2 pulleys
- allows repair of tendons inside tendon sheaths as patients can demonstrate that the inside of the sheath has not been inadvertently caught
- facilitates postop early active motion
- immobilize for 3 days
- begin active midrange motion after day 3 (form a partial fist with 45 degree flexion at MP, PIP and DIP joints, or “half a fist 45/45/45 regime”)
Flexor tendon reconstruction
requirements
- supple skin
- sensate digit
- adequate vascularity
- full passive range of motion of adjacent joints
Flexor tendon reconstruction
techniques
- single-stage procedures
- two-stage procedures
single-stage procedures RECON
single-stage procedures
- only perform if the flexor sheath is pristine and the digit has full ROM
two-stage procedures RECON
- Hunter-Salisbury
- Paneva-Holevich
Hunter-Salisbury
- Stage I - SR is placed to create a favorable tendon bed
- Stage II (3-4 months) - SR is retrieved and a tendon graft is placed through the mesothelium-lined pseudosheath
- pulvertaft weave proximally and end-to-end tenorrhaphy distally
Paneva-Holevich
- Stage I - SR is placed in the flexor sheath, pulleys are reconstructed (as needed), and a loop between the proximal stumps of FDS and FDP is created in the palm
- Stage II - SR is retrieved, FDS is cut proximally and reflected distally through the pseudosheath and either attached directly to FDP stump or secured with a button
Advantages AND Disadvantes of Paneva-Holevichages
-
advantages
- graft (FDS) size is known at the time of silicone rod selection
- less graft diameter-rod diameter mismatch
- FDS graft is intrasynovial
- fewer adhesions than extrasynovial grafts
- relies on only 1 tenorrhaphy site (distal or proximal) to heal at any one time (vs. Hunter technique where 2 tennoprhaphy sites are healing simultaneously)
- graft (FDS) size is known at the time of silicone rod selection
-
disadvantages
- graft tensioning is at the distal end during stage II
- the proximal end has already healed after stage I
- graft tensioning is at the distal end during stage II
graft selection in recon
- palmaris longus (absent in 15% of population)
- most common
- plantaris (absent in 19%)
- indicated if longer graft is needed
- extensor digitorum longus to 2nd-4th toes
- extensor indicis proprius
- flexor digitorum longus to 2nd toe
- FDS
pulley reconstruction
- one pulley should be reconstructed proximal and distal to each joint
- pulley reconstruction should occur first if a tendon graft is being used
- methods
- belt loop method
- FDS tail method
outcomes in Recon
outcomes
- subsequent tenolysis is required more than 50% of the time
Postoperative Rehabilitation Protocols
-
Immobilization
-
Early passive motion
- Duran protocol
- low force and low excursion
- active finger extension with patient-assisted passive finger flexion and static splint
- Kleinert protocol
- low force and low excursion
- active finger extension with dynamic splint-assisted passive finger flexion
- Mayo synergistic splint
- low force and high tendon excursion
- adds active wrist motion which increases flexor tendon excursion the most
- Duran protocol
-
Early active motion
- moderate force and potentially high excursion
- dorsal blocking splint limiting wrist extension
- perform “place and hold” exercises with digits
Postoperative controlled mobilization has improved results with tendon repair why?
- especially in zone II
- improved tendon healing biology
- limits restrictive adhesions and leads to increased tendon excursion
Basic types of suturing
Simple
- Shearing parallel to bundles
- Weak
End-to-end locking
- Pull converted to compressive force around bundles
- Strength near that of suture
Interweave
- Strongest
- Bulky
Common End-to-end types
A, Bunnell
B, Crisscross
C, Mason-Allen
D, Kessler grasping
E, Mod Kessler
F, Tajima-Kessler