Flexor Tendon Injuries Flashcards
What are the origins and insertions of the following flexors:
- FCR
- FCU
- FDS
- FDP
- FPL
FCR
- O: Medial epicondyle
- I: base D2 MC
FCU
- O:Medial epicodyle, ulnar olecranon, proximal 1/3 ulna
- I: pisiform
FDS
- O: 1- Humero-ulno head: Medial epicondyle + Ulnar coronoid. 2- proximal 1/3 radius
- I: MP 2,3,4,5
FDP
- O: ulna proximal 2/3 + IOM
- I: DP 2,3,4,5
FPL
- O: Radius + IOM
- I: DP 1
Where are the Annular pulleys and crucitae pulleys located? And what its the function fo the pulley system?
- A1,3,5 over MCP joints
- A2, 4 over PP and MP
- C1 (b/w A2,3), C2 (b/w A3,4), C3 (b/wA4,5)
Function
- Maximize strength by creating s horter moment arm. With little endone xcursion, we get more ROM
What are the synovial sheaths and 3 functions
Def: fibro-osseous tunnels at the digits and wrist lined with parietal synovial lining
Function
- smooth gliding
- nutrition
- mechanical support to prevent bowstringing
What are the flexor zones
- Distal to FDS insertion
- FDS insertion to distal A1 pulley
- Distal CTR to Proximal A1 pulley
- CT
- Proximal to CT
Thumb
- Distal to IPJ
- A1 to IPJ
- Thenar eminence
What are factors to consider for timing of flexor repair
- Soft tissue coverage
- unstable fractures
- contamination
- shortening of musculotendinous unit
- concomitant injuries
What are contraindications to delayed 1 repair
- inadeqaute ST coverage
- active infection/contamination
What are principles of flexor tendon repair
- Timing
- Best outcomes if 1’ or delayed 1’ (<2wks)
- poor outcomes if >2wk delay (edema.adhesions)
- poor outcomes if >5wk delay (tendon shortening, edema)
- Length
- Tendon graft if >1cm shortened
- Tendon repair
- in zone 2, repair FDP and one slip of FDS (to prevent adhesions, maintain grip strength/prolonged grip strength, prevent swan neck deformity)
- # strands = stregnth of repair
How much of the A2 and A4 can you safely vent
- can cut up to 50% of A2 with no influence on stregnth
- Can vent A4 100% if the pulley system at PIP and DIP is intact
What is the vascular supply to the tendon
- longitudinal vessels perfusing though vincula
- intraosseous vessls
- synovial diffusion
What are tricks for retrieving the proximal stump?
- milking forearm
- skin hook
- proximal icision and feeding it forward
- insert catheter distal to proxima, suture to tendon and pull distally.
- if canal is tight, serially dilate
What are key principles for a technically sound tendon repair
Core suture repair with at least 4 strands (3-0 ticron w 6-0 prolene)
Strickland/indiana (4 strand modified kessler and Horizzontal mattress with epitendinous)
Locking cruciate 4 strand with epitendinous.
If no concerns for catching on pulley, put knot on outside
Place knot in dorsal 1/3 of tendon
What is the puporse of the epitendinous suture?
- increase stregnth of repair by 25-50% (Silverskold increasess strength by 120%)
- decreased gapping
- smooth edges of the repair
What are poor prognostic indications of flexor injury for poor recovery
- associated f#, nerve injury, crush
- delay>3ks in tratment, zone 2
What are startegies to increase the differential glide between tendons
- start ROM protocol at 2-3days post-op (5-7days too late as scar is stronger than tendon)
- need PIP ROM 0-30 for 4mm of tendon glide
- need DIP 0-30 for differential glide
How do you manage tendon repair if no A2 left intact?
use excised slip of FDS for pulley reconstruction and despite pulley recon, can start early AROM