Objective: Reconstruction of extensor functions after extensor tendon injuries of the hand.
Indications: Acute injuries of extensor mechanism with corresponding loss of function.
Contraindications: Complex injuries with loss of soft tissue. Limited possibility of extensor tendon reconstruction with combined injuries of the interphalangeal joints (in situations with irreparable joints: primary arthrodesis).
Surgical technique: The treatment of extensor tendon injuries depends on the various levels of tendon laceration. Zones 1 and 2: in case of tendon disruption close to the base of the distal phalanx, refixation of tractus terminalis using a pull-out suture. In case of disruption more proximally, primary repair using mattress sutures. Temporary pinning of the distal interphalangeal joint in extension using a single transarticular Kirschner wire. Zone 3: mattress sutures of the tractus intermedius. Temporary pinning of the proximal interphalangeal joint in extension using a single transarticular Kirschner wire. Zone 4: reconstruction of the central slip and the lateral slip of extensor tendon using modified Becker sutures and mattress sutures. Temporary pinning of the proximal interphalangeal joint in extension using a single transarticular Kirschner wire. Zones 5 and 6: four-strand modified Becker sutures with additional epitendinous suture. Zones 7 and 8: core sutures using modified Kirchmayr techniques with additional epitendinous suture.
Postoperative management: Zones 1-4: immobilization of the finger for 6 weeks with removal of the transarticular wire at 4 weeks. Zones 5-8: dynamic postoperative treatment in intrinsic-plus splint for 6 weeks.
Results: It is postulated that dynamic postoperative treatment leads to improved functional outcome after extensor tendon injuries. While for zones 1-4 no better final clinical results are observed using the dynamic postoperative protocol, early protected motion for zones 5-8 is superior to static post operative treatment.