Flexor Tendon

Question 1

Discuss Flexor Tendon Lac Treatment

Answer 1

• if < 60% tendon width: NO SURGERY! treat with trimming of frayed edges and early ROM (no need to repair or immobilize!)
  
  • 60-75%: epitendinous repair only (no core sutures needed)
  • > 75%: Repair should involve a RUNNING EPITENDONOUS SUTURE (best type of suture to allow BEST GLIDING! Lowest resistance!), also bites should be 10 mm from cut edge (this distance is best to make strong so can move finger early!) and CORE SUTURES
    • 4-6 core sutures
    • The core sutures provide the GREATEST STRENGTH to the repair
  • ROM should occur with wrist in gentle flexion and gentle flexion up to making 1/2 fist
  • Note: in pedi flexor tendon injuries these differ from adult in that you must immobilize them for 3-4 weeks bc of their inability to be compliant with postop restrictions for safe ROM
  • Wide awake flexor tendon repair is performed using Lido WITH EPINEPHRINE
    
    • Wide awake surgery helps ID gapping and eval tendon gliding this allows early active ROM

Question 2

How do you test FDS?

Answer 2

• FDP has common muscle belly to the ulnar 3 digits - thus independent flexion of any finger w/ others restrained in extension requires intact FDS functions to that finger.
  
  • so if you want to test FDS to these digits -> hold the other 2 ulnar digits completely extended and you need an intact FDS to flex the digit at PIP b/c you will be unable to pull through the FDP since it is being retrained by the other digits being held extended.

Question 3

Quadrigia Effect

Answer 3

Due to common muscle belly of FDP, if during repair of the MF, RF, SF you over shorten (by > 1 cm) the tendon you will get inability to fully flex the other digits into the palm (example below after RF FDP repaired shortened > 1 cm) due to over tensioning

Question 4

Treatment of chronic FPL lac

Answer 4

• Chronic laceration is generally > 3 weeks old

* Complete chronic FPL laceration -> if digit has good passive motion then perform TENDON TRANSFER: FDS from 4th digit

Question 5

Rupture of previously repaired flexor tendon

Answer 5

• If pulleys are still open (ie can slide a catheter through) -> single stage reconstruction with PL autograft
  
  • If pulleys are collapsed -> treat as chronic with 2-stage reconstruction described below

Question 6

Treatment of FDP avulsion/Jersey finger

Answer 6

urgency of surgical treatment to reattach comes from the fact that you do not want the tendon to retract more bc this ruins the blood supply to the tendon (vincula) more

Question 7

Chronic Jersey Finger (and FDP to any finger) injury (> 3 mo) treatment

Answer 7

• 2-stage tendon grafting
  
  • 2-stage grafting involves:
    
    • 1) implanting a silicone rod in 1st stage - this allows formation of a pseudosheath around the silicone
    • 2) Free tendon graft (typically Palmaris longs or planteris) through pseudosheath (pseudosheath limits adhesions to the tendon graft! So get better ROM!)
  • Note: Single-stage flexor tendon grafting isn’t as good b/c get adhesions to which significantly limit ROM.

Question 8

Discuss anatomy of flexor pulley system

Answer 8

• A1, A3, A5 - overlay the joints; arise from the palmar plates
• A2, A4 - overly the proximal and middle phalanx; MOST important biomechanically - prevents bowstringing and maximizes excursion
• C1, C2, C3 - are thin and condensible and allow the annular pulleys to approximate each other during finger flexion
• Thumb pulley -> must have A1 or Oblique pulley AND A2 pulley in order to have good biomechanics