Microsurgery: Transplantation and Replantation by Harry J. Buncke, MD, et al.
  Table of Contents / Chapter 33:
Secondary Reconstruction After Replantation
  Once the decision to tenolyze a digit has been made, several factors must be considered. Circulation is further compromised by the procedure itself, and therefore exploratory incisions should protect and preserve the vascularized side. Consideration may even be given to augmenting the circulation with interpositional grafts to the nonrepaired side, particularly if the perfusion is poor or damage to the repaired side is suspected. A zigzag Brunner midline surgical approach provides excellent exposure to the tendon pulley mechanism and protects the neurovascular territories. The tenolysis should be performed as anatomically as possible, preserving tendon bulk and pulleys. 39,40 The proximal part of the A-1 pulley and the distal A-4 pulley must be preserved to prevent bowstringing and preserve efficient tendon excursion. If the proximal pulley system is destroyed, simultaneous tenolysis and pulley reconstruction may be counterproductive. If the tendon is of poor quality, thinned out, or bridged with scar tissue at the site of repair, it is wiser to debride the tendon, reconstruct the pulleys, and insert a tendon rod than to accept a high risk of tendon rupture, pulley stretching, or readhesion of the entire complex. 27,39 Occasionally, pulley reconstruction can be considered at the same time as tenolysis if the tendon is of good quality and residual flexor sheath material is available for the reconstruction of a "gutter multiple weave" type of pulley. 46 Other options in which the tendon and pulley are of poor quality are the tenodesis or fusion of the distal and/or PIP joints and the acceptance of a sublimis finger or a finger with only MP function.14 Again, all the variables must be considered and only compatible procedures performed simultaneously. In general, tenolyses are not performed with osteotomies, joint fusions, bone grafts, or nerve or vessel repairs which require postoperative immobilization. Recent studies,47,48 however, have shown that proper bone stabilization will tolerate early forceful motion and all rules must be tempered with judgment and flexibility when planning combined procedures and postoperative mobilization. Conversely, tenolyses, arthrolyses, and arthroplasties may be performed simultaneously.

  Unlike the flexor mechanism, where secondary tendon procedures at more proximal levels (Zones II to IV) have diminishing returns, the success of secondary repairs of the extensor mechanism is inversely related to the level of injury. Proximally, the extensor tendon is a repairable structure, but distally the entire mechanism thins out and becomes conelike, sheathing the underlying bony structures, where it is prone to fusion with the laminated deeper structures. The delicate gliding mechanism almost defies duplication. The lateral bands and extensor hood, once transected, retract proximally and distally and are seldom selectively repaired during replantation. The loss of the intrinsic pull across the PIP joints often results in hyperextension, with a mallet flexion deformity at the DIP joint. Fortunately, flexion contractures of the PIP help to prevent this from occurring. Extensor tenolysis, intrinsic reconstruction, and dorsal arthrolysis are worthwhile when active and passive flexion are present.

Secondary Bone and Joint Operations

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