Practical Plastic Surgery

1.Bone shortening followed by rigid fixation—if ischemia time is an issue, circulation should be restored prior to bony fixation

2.Flexor tendon repair—some authors will repair only the profundus tendon

3.Extensor tendon repair

4.Arterial anastomosis—at least one artery is usually required

5.Venous anastomosis—at least two veins for more proximal digital amputations. Level I amputations can be replanted without venous anastomosis

6.Nerve repair—this is optional, and may be delayed for a secondary procedure

7.Soft tissue coverage—skin grafts are sometimes required, especially in avulsion injuries. Vein grafts can be harvested with overlying skin as a composite graft

Bone Fixation

Fixation of an amputated digit can usually be achieved with crossed Kirschner wires passed retrograde through the amputated digit into the finger stump. Amputations through the proximal phalanx (Level IV) may require plate fixation for early postoperative mobilization. Transmetacarpal, transcarpal, and forearm amputations also require screw and plate fixation. This should be followed by periosteal repair, when indicated, to minimize tendon adhesion to the plates.

Vascular Repair

The arteries and veins must be trimmed back until normal intima is apparent. In order to minimize spasm, topical papavarine or concentrated lidocaine can be administered. Alternatively, a Fogarty catheter can be used to break a spasm. In crush or avulsion injuries, a vein graft may be required. Vein grafts can be taken from the dorsum of the foot, from the volar wrist, or from the dorsum of the hand. Alternatively, the lesser or greater saphenous systems can be used. The length of donor veins should be measured in situ since they shrink after harvest. Vein grafts should not be excessively long, since this can lead to kinking.

Arterial repair is usually done first. Prior to venous repair, the appearance of the replanted part should be assessed for several minutes after completion of the arterial anastomosis to confirm adequate perfusion. After the replant has warmed up, bleeding from the veins to be anastomosed should be brisk.

Level I digital amputations can be replanted without a venous anastomosis. At least two veins are required for proximal digital amputations. If necessary, digital veins can be transferred from an adjacent digit. Venous drainage can also be achieved with a proximally based cross-finger flap. If the contralateral digital artery has retrograde blood flow, it can be anastomosed to a vein to provide outflow. Finally, if no vein can be identified, the nail is removed and a heparin-soaked sponge is placed on the nail bed, or leeches are applied to the tip of the digit.

Tendon Repair

Debridement of the tendon ends should be minimized to avoid the need for tendon grafting. Most surgeons repair the extensor tendons first, and many postpone repair of the flexor tendons. In Zone II flexor tendon amputations, some surgeons will elect to repair only the FDP tendon. A core suture technique is used; this is described in detail in Chapter 90.

82 Nerve Repair

Nerves should be repaired primarily whenever possible with 8-0 or 9-0 suture. A description of primary nerve repair is discussed in the nerve repair chapter. When necessary, nerve grafts can be taken from a number of sites: a nonsalvageable digit, the posterior interosseus nerve, the lateral femoral cutaneous nerve, the superficial peroneal nerve, and the sural nerve. Vascularized nerve grafts have also been described. Difficult nerve repairs may be delayed after the nerve ends are identified and tagged. Sensory outcomes of digital replantation are improving. Two-point discrimination of 10 mm or less has been reported.

Soft Tissue Coverage

In order to avoid compression of the vascular anastomoses, the skin must be closed in a tension-free fashion. If this cannot be accomplished, a split-thickness skin graft should be used. In forearm or more proximal amputations, soft tissue loss may be extensive, requiring local or free flap coverage.

Special Considerations

Ring Avulsions

Outcomes for ring-avulsion replants are not as good as for amputations. Success rates range from 30-70%, depending on the extent of injury. Ring avulsions range in severity, from tearing of the soft tissue with intact circulation to complete degloving of the digit. In degloving injuries, vein and nerve grafts are required. Repair of thumb avulsions should always be attempted, while fingers avulsed through the PIP joint should be amputated.

Hand and Forearm Amputations

Amputations through the carpal region have generally good functional outcomes. Transmetacarpal amputations, however, have a much poorer long-term prognosis. This is in part due to the many small vessels that are severed in these injuries. In any

case, chronic swelling of the hand is common so many surgeons will release the carpal tunnel and dorsal interosseous compartments at the time of surgery.

Of all the tissue in the upper extremity, muscle is least tolerant of ischemia. In proximal amputations, restoration of blood flow is the first priority since more muscle is involved. Prophylactic forearm fasciotomies are often performed if warm ischemia time is prolonged. Proximal amputations will usually require secondary procedures such as nerve grafts and tendon transfers.

Postoperative Care and Monitoring

At the completion of the procedure, the extremity should be placed in a well-padded splint without any circumferential dressings since swelling is inevitable. The fingertips should be exposed so that they can be monitored postoperatively.

The patient must be kept in a warm room with the extremity elevated above the heart. A continuous axillary anesthetic block can help with pain control and act as a chemical sympathectomy. Aspirin should be given since it has a potent anti-platelet effect. Although many centers use some form of anticoagulation, no randomized control trials have demonstrated a benefit to any regimen. The patient should be hydrated with intravenous fluids to avoid hypotension.

Monitoring the circulation after replantation is similar to a free-flap as discussed 82 in the chapter on free-flap monitoring. Early detection of microvascular failure is critical for salvage of the replant. The most reliable means of monitoring a replanted

digit is a clinical exam by an experienced individual combined with pulse oximetry or Doppler monitoring. SpO2 values above 95% are normal; a saturation below 85% indicates a venous problem, and a complete lack of signal indicates and arterial problem. Arterial and venous Doppler monitoring is used in many centers; both pencil and laser Doppler can be used. Finally, removal of the nail with monitoring of nail bed bleeding provides a rudimentary means of monitoring arterial circulation.

Outcomes

The most common early complications after replantation are bleeding, infection and loss of the replant. Late complications include cold intolerance, bony nonunion, nerve or tendon adhesions requiring neurolysis or tenolysis, and late necrosis of the replanted part.

Centers with a highly experienced replantation team report survival rates of 90-100% for digital replants. Level II amputations generally do better than Level I amputations. In terms of sensory recovery, two-point discrimination of 10 mm or less has been reported in a number of series. In both adults and children, persistent cold intolerance is common.

Pediatric Replantation

Many surgeons agree that unless a contraindication exists, almost all amputations in children should undergo replantation. Long-term follow-up at 15 years has demonstrated return of normal sensation, strength, and bone growth in up to 90% of digital replants in children. Distal finger tip amputations have been shown to survive with composite grafting when microvascular replantation is not possible. Even in these cases, sensory recovery can be excellent, presumably due to spontaneous neurotization. In children, bone shortening should be undertaken with caution to protect the epiphyseal growth plate so that the replanted bone will continue to grow normally.

Pearls and Pitfalls

Three of the leading replant teams, the Kleinert-Kutz group, the Buncke group, and the Tamai group, have emphasized several important points in replantation technique:

•Bone shortening to reduce tension on the vessels, tendons, and nerves

•Repair of both the artery and vein before tourniquet release

•Heparin bolus after completion of the anastomosis

•Washing out the intravascular clots from crushed digits or hands

•The use of “spare parts” from unreplantable digits

•Transposing an amputated digit onto a different stump in cases of multiple digit amputations

Suggested Reading

1.Buncke Jr HJ. Microvascular hand surgery—Transplants and replants—Over the past 25 years. J Hand Surg 2000; 25A:415.

2.Kim JYS, Brown RJ, Jones NF. Pediatric upper extremity replantation. Clin Plast Surg 2005; 32:1.

3.Kleinert HE, Jablon M, Tsai TM. An overview of replantation and results of 347 replants in 245 patients. J Trauma 1980; 29:390.

824. Lee BI, Chung HY, Kim WK et al. The effects of the number and ratio of repaired arteries and veins on the survival in digital replantation. Ann Plast Surg 2000; 44:288.

5.Pederson WC. Replantation. Plast Reconstr Surg 2001; 107:823.

6.Soucacos PN. Indications and selection for digital amputation and replantation. J Hand Surg (Br) 2001; 26B:572.

7.Tamai S, Michon J, Tupper J et al. Report of the subcommittee on replantation. J Hand Surg 1983; 8:730.

8.Weinzweig N, Sharzer LA, Startker I. Replantation and revascularization at the transmetacarpal level: Long-term functional results. J Hand Surg 1996; 21:877.

83

Traumatic disruptions of these relationships can destroy the normal kinematics of the wrist and lead to reduced range of motion and degenerative arthritis.

Fractures

A variety of fractures can occur in the radius and ulna after the common traumatic history of, “fall on an outstretched hand”. These are amongst the most common skeletal injuries and occur more frequently in children and the elderly. Fractures of the distal radius are best described in terms of their comminution, articular involvement, displacement and angulation with particular attention paid to the measurements of ulnar variance, inclination, and volar tilt. Eponyms are frequently used for expediency, though these can lead to confusion for inexperienced evaluators. Fractures of the ulna are often multiple and can have varying degrees of clinical significance. Recall that the radius and ulna essentially form a ring between the elbow and wrist and, as is seen with the mandible, a fracture of one side of the ring will usually result in a fracture at the other.

The most common fracture, is a dorsally angulated, extra-articular fracture of the distal radius, otherwise known as a Colles’ fracture. A Smith’s fracture is a volarly

angulated, extra-articular fracture and generally occurs from a fall onto the dorsum of the hand. A Barton’s fracture is an intra-articular fracture and can be either volarly or dorsally angulated. A Chauffeur’s fracture is an intra-articular fracture of the radial styloid, usually caused by forced extension and radial deviation of the wrist. The name originates from the chauffeurs who were sent to start the old Model-T Fords with the hand cranks, which would occasionally backlash onto the wrist, fracturing the radial styloid. Occasionally, a fall on an outstretched hand can occur with such force as to cause a Monteggia fracture, which is an unstable fracture of the proximal ulna with dislocation of the radial head. These fractures must be repaired operatively with reduction of the radial head and plate fixation of the ulnar fracture.

Evaluation

The evaluation of injuries to the radius and ulna always begins with a thorough history and physical exam of the hand. Though the injury may be immediately obvious, it is imperative that the entire hand and arm be evaluated in a careful, systematic manner so that all associated injuries are identified and treated. A thorough history of the injury is taken, including hand dominance and occupation. Ask about previous injuries to the extremity as well as relevant medical problems such as arthritis or carpal tunnel syndrome. A detailed description of the mechanism of injury can be helpful as well as associated symptoms such as numbness and tingling.

Next, inspect the arm from shoulder to fingertip and note any bruising, lacera- 83 tions, and deformities. Take note of the manner in which the patient holds the

arm at rest and note any pallor, cool skin or lack of sweating. Then, gently palpate the arm along its entire length to determine areas of tenderness and deformity. Evaluate the range of motion of all joints, taking into account local edema or arthritis which could limit mobility. Remember to evaluate pronation and supination of the forearm. Next, systematically check each long flexor and extensor of the wrist and fingers, as well as the intrinsic muscles of the hand. Finally, confirm that the radial, ulnar, and median nerves are intact and functioning. Entrapment or compression of these nerves can change a simple fracture of the wrist into a medical emergency requiring prompt reduction and decompression before permanent nerve damage occurs.

Example of a Correct Fracture Description

Figure 83.3 illustrates a common fracture and the correct means of describing it. An unacceptable call to one’s chief resident to describe the above fracture would go something like this: “The patient has broken her right wrist”. A professional call to the chief resident would be more along the lines of: “The patient is an 86 year old, right hand dominant female with a history of osteoporosis who fell on an outstretched right hand today while walking her dog. She has an obvious, painful deformity of her right wrist with no open wounds and no vascular compromise or loss of sensation. Her radiographs display an unstable, severely comminuted, intra-articular fracture of her distal radius and ulna styloid. The fracture is volarly displaced with an ulnar positive variance of 5 mm. She has an inclination of 14˚ and a volar tilt of -4˚. There is significant articular incongruity.

Treatment

The aim of treatment is to return the fracture as nearly as possible to a normal anatomic alignment with minimal morbidity to the patient restoring adequate length (ulnar variance) and volar tilt are key. The choice of treatment depends entirely on an

83Figure 83.3. AP and lateral radiographs illustrating an example of a comminuted, intra-articular fracture of the distal radius and ulna styloid.

accurate assessment of the injury. A simple, minimally displaced fracture can be treated with cast immobilization for a period of 3-4 weeks. A displaced Colles’ fracture can be treated with closed reduction, followed by application of a sugar tong splint, then cast immobilization for 4 weeks. Unstable fractures, intra-articular fractures and comminuted fractures frequently require more rigid fixation. Closed reduction with K-wire fixation is minimally invasive and adequately treats most unstable fractures that are not comminuted. However, most hand surgeons have largely shifted towards the use of a volar plate for rigid fixation. Comminuted and intra-articular fractures often need to be reduced openly in the OR, then rigidly fixed with a volar plate to hold optimal alignment. The advantage of this is an early return to activity and avoidance of joint stiffness. The downside is a trip to the OR and its inherent risks. Sometimes, the fracture is so comminuted that it won’t hold a plate or the bone is too osteoporotic to hold screws and an external fixator is required. These are bulky and cumbersome but neutralize the compression force and help to maintain length.

Volar Plate Technique for Distal Radius Fractures

After exsanguination of the arm, a longitudinal incision is made over the distal portion of flexor carpi radialis (FCR). The incision is carried through the tendon sheath down to the tendon. Care must be taken to avoid injury to nearby structures such as the radial artery and palmar cutaneous branch of the median nerve. The FCR tendon is retracted radialy, and the pronator quadratus is visualized. The muscle is incised sharply, leaving a cuff of tissue on the radial side so that the muscle can be sewn back into place to cover the plate. It is then elevated in the subperiosteal plane off the distal radius with care to preserve its integrity. The periosteum of the distal radius including the fracture site is carefully elevated. The fracture is exposed, curetted, and reduced under fluoroscopy. Radial length and volar tilt must be restored. A multitude of companies produce volar plates. All are essentially locking plates with

a prefabricated bend in the plate that matches the normal volar tilt. Once all the screws are placed, fluoroscopy is used to confirm the final result. The site is irrigated and the pronator reapproximated to cover as much of the plate as possible. The skin is closed with 4-0 nylon horizontal mattress sutures. A bulky dressing and volar splint are applied. The rigid fixation provided by the volar plate allows for early postoperative motion.

Pearls and Pitfalls

•X-ray all injured extremities including one joint proximal and distal to the level of injury.

•Reduction before fixation.

•When one forearm bone is fractured, look for another fracture in the other bone or a disruption of the joint at the wrist or elbow.

•Look for associated carpal injuries such as a scaphoid fracture or scpaholunate dissociation (tear of the scapholunate ligament).

Suggested Reading

1. Chang B. Principles of upper limb surgery. Chapter 65. Grabb and Smith’s Plastic Surgery. 5th ed. Philadelphia: Lippincott-Raven, 1997.

2. Fernandez DL, Palmer AK. Fractures of the distal radius. Chapter 29. Green’s Opera- 83 tive Hand Surgery. 4th ed. Philadelphia: Churchill Livingstone, 1999.

3.Leibovic SJ. Fixation for distal radius fractures. Hand Clin 1997; 13:665.

4.Trumble TE, Schmitt SR, Vedder NB. Factors affecting functional outcome of displaced intra-articular distal radius fractured. J Hand Surg 1994; 19:325.