After the patient has been stabilized, prior to transfer to the operating suite, the part is taken to the operating room for inspection and tagging of all the structures (Fig. 6.3a, b). Upper arm and forearm replants are routinely performed with two teams (Fig. 6.4). One team performs the debridement and tagging of the amputated part, while the other team does the same on the patient’s arm. The sequence of events is summarized below in a stepwise fashion (some exceptions made depending on ischemia time):

We start by inspecting the part for any debris or foreign bodies. The part is washed thoroughly with soap and water; all debris is removed and the part is then prepped with Betadine solution. During the preparation of the part, we prefer to place the hand flat on a chilled iced container. Prior to tagging the structures, we inspect the part and debride all the nonviable skin and subcutaneous tissues. Tendons are trimmed to healthy appearing substance and we reserve debriding the nerves and arteries until microscopic magnification is in place so that appropriate inspection of the intima and nerve fibers is performed.

By this time, the surgeon should have in mind a surgical plan for the bony fixation. If the mechanism of injury is through the proximal row, we perform the PRC of the part on the tagging table. If the proximal and distal rows are injured, restoration of a functional radiocarpal joint will be impossible, so we remove the proximal row and save the bone for bone grafting to help with wrist arthrodesis.

The part is carefully inspected for injuries. We normally test all the flexor tendons to make sure they are gliding properly and under fluoroscopy rule out any other bony injuries. If fractures or dislocations exist in the amputated part, K-wire fixation is performed prior to tagging the structures. We start volarly by opening the carpal tunnel and Guyon’s canal. The median and ulnar nerve are identified and neurolyzed. The flexor tendons are identified and a DOLLS (double-opposing, locking-loop suture)-type suture with 4-0 FiberWire is placed on all the FDS and FDP distal stumps [25]. Then the radial artery and ulnar artery are identified and released appropriately to ensure a tension-free repair.

The hand is then turned dorsally and exposure to the extensor tendons is done taking into consideration the venous drainage of the wrist. The two major draining veins are the cephalic and the basilic veins that drain the metacarpal venous plexus (Fig. 6.5). The exposure to the dorsum is usually done in an H-type pattern, being conservative with the skin incisions (Fig. 6.6a, b). The draining veins are identified and clipped as downstream as possible to preserve length. The extensor tendons are dissected free just enough to ensure an appropriate repair.

In anticipation of swelling associated with ischemia and reperfusion of the intrinsic muscles, the compartments of the hand are released. Two dorsal incisions (approximately 2 cm each) are made on the second and fourth compartment and the fascia is released. However, the surgeon should not disrupt the dorsal venous drainage when releasing the dorsal compartments. Similarly, the thenar and hypothenar compartments are released volarly. Lastly, the superficial branch of the radial nerve is identified and tagged. The part is then handed off to the sterile table (Fig. 6.7).

Simultaneously, the patient is prepped and draped with a nonsterile tourniquet in place, and the second team begins debriding the forearm stump. Depending on the extent of injury, the thigh and leg are prepped as well for possible vein, skin, or tendon grafting. Nonviable skin, subcutaneous tissue, tendons, and muscle are inspected and debrided appropriately. Important decisions are made while this process is taking place; the surgeon must determine at this time the viability of the radiocarpal joint and decide if the joint is appropriate for a proximal row carpectomy, arthrodesis, or radial shortening. The motor units are inspected and the zone of injury assessed. This will determine if vein grafts, nerve grafts, or tendon grafts will be needed. Specifically, we tend to address each soft tissue compartment separately. The skin is inspected and surgical release of compartments is planned so that vital structures are covered. In addition, if there is a soft tissue deficit, and the patient might need microvascular transplant down the road, we plan our incisions so that the vascular anastomoses are protected. When available, healthy skin and subcutaneous coverage is limited, we prefer to prioritize this coverage to vessels and nerves, leaving muscle and tendon to coverage with skin grafts or dressing changes. When no good coverage is available, we have skin grafted over vessels and nerves as a temporizing measure to protect them from desiccation.

Depending on the pattern of injury, we extend our incisions proximally after the debridement is performed, usually in an H pattern. The forearm fascia is released and the structures inspected and tagged appropriately in a similar fashion as the part. The flexor tendons are tenolyzed and separated individually to match the distal targets. We start by tagging the deeper structures such as the FDP and move volarly to the FDS. The radial artery and ulnar artery are identified and tagged. The ulnar nerve and median nerve are neurolyzed and tagged. Dorsally the extensor tendons are identified and the accompanying draining veins are tagged. Usually the cephalic vein is sufficient for transcarpal replants, but the carpus has several proximal appropriate targets. As in the case of the amputated hand, it is important to release the forearm fascia to account for postoperative swelling.

Technically, transcarpal replants are relatively straightforward. The vessels are larger, the carpal venous drainage is constant, and the muscle units are excluded from the zone of injury. The tendinous repairs are performed primarily and the functional results are excellent [10, 12, 14, 26]. However, in order to achieve a tension-free repair without the use of nerve or vein grafts as well as to prevent tight tendon repairs, bone shortening must be address in a systematic fashion. Bony fixation is dependent on the mechanism of injury through the carpus itself. As outlined previously, the bone is addressed in three different ways: (a) proximal row carpectomy, (b) wrist arthrodesis, and (c) radial and ulnar shortening or Darrach procedure for the ulna assuming carpus is intact.

Bony fixation is determined by the mechanism of injury and the quality of the carpal bones. The decision to perform an arthrodesis versus a proximal row carpectomy is primarily dependent on the integrity of the distal row and the lunate facet. If there is bony injury to the any of the bones of the distal row, we inspect the carpal bones and if possible perform open reduction and internal fixation of the damage bones to preserve the distal row and attempt wrist salvage with a PRC. If, however, there is comminution or intracarpal instability or the injury is extensive, we proceed with arthrodesis. Unfortunately, few radiocarpal amputations are clean through the joint and have an intact capitate-lunate joint; nevertheless an attempt to preserve motion to the wrist should be a priority.

If the mechanism of injury is through the proximal and distal carpus, we remove the proximal carpus and perform a wrist arthrodesis. We use the proximal carpus as bone graft and shorten the wrist by 2–3 cm. If more bone graft is needed, we used iliac crest as a donor site. Arthrodesis with a dorsally placed plate offers the greatest stability and lowest chance for nonunion. Plates specifically designed for this are readily available, with the most common employing a slight bend at the level of arthrodesis that allows positioning of the wrist in roughly 20–30° of extension. Proximally, the plat should be positioned along the centerline of the radius, typically along the floor of the fourth compartment. Removal of Lister’s tubercle and contouring of a slight trough in the dorsal aspect of the distal radius can facilitate accurate placement and alignment of the plate. If a straight plate is employed, contouring of the distal radius is not necessary. When dissecting the middle finger metacarpal for distal plate placement, the venous drainage must be preserved and protected if the drainage is through the carpal circulation.

The second option is to perform a proximal row carpectomy (Fig. 6.8a–n). The decision can be made while inspecting the part, and the carpectomy should be performed simultaneous with debridement of the stump. Important for obtaining a good outcome, the proximal capitate and lunate fossa should be relatively uninjured. Postoperatively, the wrist motion in this group of patients is excellent [14, 27]. Temporary fixation is performed with a pair of 0.062 k-wires through the radiocarpal joint capturing the lunate fossa and capitate as well as the scaphoid fossa and trapezium. A third k-wire is place through the ulna to the hamate. Routinely, we perform radial styloidectomy to prevent impingement with the distal row. The radial styloidectomy can be performed with a rongeur or an osteotome prior to the bony fixation of the part.