| Introduction |
 Zone I
- Mallet finger
- Zone II
- usually caused by laceration or crush
- Zone III
- Boutonneire deformity
- Zone IV
- Zone V
- Zone VI
- Zone VII & VIII
- postoperative adhesions common
- must repair retinaculum to prevent bowstringing
- tendon repair followed by immobilization with wrist in 40° extension and MCP joint in 20° flexion for 3-4 weeks
- Zone IX
- extensor muscle belly of forearm
- usually from penetrating trauma
- often have associated neurologic injury
- tendon repair followed by immobilization with elbow in flexion and wrist in extension
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| Treatment |
- Nonoperative
- immobilization with early protected motion
- indications
- lacerations < 50% of tendon in all zones
- extension splinting of DIP joint for 6-8 weeks
- indications
- acute Zone 1 injury (Mallet Finger)
- Operative
- immediate I&D
- tendon repair
- indications
- laceration > 60% of tendon width in all zones.
- tendon reconstruction
- indications
- indicated in chronic injuries or when repair not possible
- EIP to EPL tendon transfer
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| Surgical Techniques |
- Tendon Repair
- incision technique
- always cross flexion crease transversly or obliquely to avoid contractures (never longitudinal)
- suture technique
- # of suture strands that cross the repair site is more important than the number of grasping loops
- linear relationship between strength of repair and # of suture crossing repair
- 4-6 strands provide adequate strength for early active motion
- circumfrenital epitendonous suture
- improves tendon gliding
- improves strength of repair (adds 20% to tensile strength)
- allows for less gap formation (first step in repair failure)
- repair failure
- tendon repairs are weakest between posteroperative day 6 and 12
- repair usually fails at knots
- Tendon Reconstruction
- usually done as two stage procedure
- first a silicon tendon implant is placed to create a favorable tendon bed
- wait 3-4 months and then place biologic tendon graft
- only perform single stage reconstuction if flexor sheath is pristine and digit has full ROM
- available grafts include
- palmaris longus (absent in 15% of population)
- plantaris (absent in 19%)
- indicated if longer graft is needed
- long toe extensor
- pulley reconstuction
- one pully should be reconstucted proximal and distal to each joint
- methods include belt loop method and FDS tail method
- Tenolysis
- indications
- adhesion formation with loss of finger flexion
- wait for soft tissue stabilization (> 3 months) and full passive motion of all joints
- postoperative
- follow with extensive therapy
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| Complications |
- Adhesion formation
- leads to loss of finger flexion
- common in Zone IV of the finger
- prevented with early protected ROM
- treated with tenolysis
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