The application of a dressing marks the end of surgery and is in itself an art form. The dressing is the only part of surgery that the patient can visualize and immediately appreciate. For the patient it is the immediate benchmark of the quality of surgery received. It serves multiple functions that include support for the operated hand and protection of repairs. Immobilization of the hand and injured fingers has an analgesic effect. The position of immobilization also protects against stiff joints. This same dressing can promote drainage and prevent formation of hematoma that is harmful in patients who undergo critical microsurgical procedures. In this same group the dressing should be designed to allow for convenient flap or replant monitoring. The dressing is an essential part of surgery and is the surgeon’s responsibility. It cannot and should not be delegated.
The type and amount of postoperative dressings used vary from one practice to another. However, all would agree that the overall appearance of the extremity should be clean and neat. The dressing itself should be dry and stain-free. Blood and plaster stains should be meticulously cleaned off the patient’s nails, fingers and elbow creases or arm before the patient is transferred out of the operating theater. The dressing itself should appear neat with smooth, well-padded edges.
Position of Immobilization
Certain surgical procedures, such as flexor or extensor tendon repairs, dictate the position of joint immobilization after operation. In the absence of specific requirements, the ideal position for joint immobilization is called the position of safe immobilization. The wrist is positioned in 20–45 degrees of extension, the metacarpophalangeal (MCP) joints are flexed to 60–80 degrees, and the interphalangeal joints are extended 0–10 degrees.
Our hands are the end organs in a multilink chain that makes up our upper limb. The function of our fingers, being the most distal segments in the chain, is affected by position of proximal joints. Maximum grip strength is observed when wrists are in 35 degrees of extension and 7 degrees of ulnar deviation. Finger joints are easier to rehabilitate if immobilized with collateral ligaments under tension. Keeping the MCP joints maximally flexed uses the dorsal-volar diameter of the metacarpal head to maintain the collateral ligaments, which originate dorsal to the axis of rotation, in their full length. The proximal interphalangeal (PIP) joints are safely immobilized in extension. However, this is not because of the resting length of the main collateral ligaments. The PIP joint main collateral ligaments are at a constant tension throughout the range of motion. It is the accessory collateral ligaments, the dorsal fibers of the flexor sheath, and check rein ligaments of the PIP joints that shorten in flexion. One should also remember to keep the thumb widely abducted to prevent first webspace contracture.
The many dressing techniques all have the common aim of forming a clean barrier between the wound and the environment, providing pain relief and minimizing postoperative swelling. This is achieved by a conforming (rather than compressive) dressing. A conforming dressing applies a uniform degree of pressure on the entire hand. It is snug enough to control capillary oozing and obliterate tissue cavities, but not constrictive enough to prevent venous return and cause swelling distally. A compressive bandage is not advised.
Immediately after surgery a plaster or resin slab is incorporated into the dressing to help maintain the position of safe immobilization. This provides support and pain relief to the injured hand. The slab and bandage form a single inseparable unit. It is placed on the cotton bandage with adequate padding and carefully molded, taking care to avoid forming pressure points that can further injure the patient. There should be enough padding to prevent the plaster or resin from sticking to the patient’s skin, but not so much that it could hamper proper molding of the slab. Immobilization for pain relief should last only until the first wound inspection, unless it is required for other purposes because of the specific procedure performed. The use of a conforming dressing applies to succeeding dressing changes. If further immobilization is required, a new customized molded orthosis should be fabricated over a light dressing after the first wound inspection. One cannot expect the new dressing to faithfully reproduce the curves and contours of the first; hence the first slab should not be reused. The period of immobilization should not be prolonged more than necessary; any prolonged immobilization has serious consequences.
Severe trauma, such as that caused by hydraulic presses, carries the risk of severe edema. Surgery in itself causes edema. The first 10 days postoperatively is the critical period of edema development. MCP joints can accommodate more fluid in hyperextension, and this increases flexion of the IP joints. Persistent edema or hematoma in the joints and gliding planes of the hand causes fibrous adhesion of all structures to one another. The hand thus freezes in a faulty nonfunctional position and becomes almost impossible to rehabilitate. Therefore edema is best prevented or minimized by using a conforming dressing (as described earlier), adequate hand elevation and early mobilization. If severe edema is expected postoperatively, the slab incorporated in the dressing may not be enough to prevent the hand from assuming this nonfunctional position. Other options available include releasing incisions (described in Chapter 9 ) and temporary wiring of MCP joints in flexion for a period of not more than 10 days.
Hand elevation promotes venous and lymphatic drainage. Elevating the hand after surgery is simpler when the patient is still resting in bed. There is no need for complicated suspension systems that cause patient discomfort. The patient’s elbow is allowed to rest on the bed, and the hand is supported by cushions to keep it raised above the plane of the bed. Arm slings are prescribed for patients who are ambulatory during the immediate postoperative period. Patients should be educated on the proper use of an arm sling before its application. An arm sling applied wrongly is dangerous. If the length of the sling is too short, the elbow rests in extreme flexion, and this impedes proper venous drainage. Worse still is when the sling is too long and the hand hangs out over the edge of the sling in a dependent position, causing severe swelling.
Again, the hand should not be immobilized longer than required for protecting what was repaired or reconstructed. Active mobilization of the elbow and shoulder immediately after surgery on the hand is almost always possible and should be encouraged. This activates muscle pumps and improves venous drainage. Mobilization of the healthy fingers should also be encouraged if it does not compromise repairs on the operated finger. This prevents adhesion of gliding planes and joint stiffness. Passive mobilization of the injured finger is sometimes an alternative to strict immobilization. In all cases, early mobilization is a key factor in improving functional outcome.
Technique of Application ( Figs. 18.1 and 18.2 )
A nonadherent dressing should be applied over areas where skin is not intact. This prevents additional wound trauma during removal. We begin by placing sheets of a nonadherent tulle (Urgotul) in direct contact with incisions or wounds. This dressing is available in various sizes that can adapt to all the geometries of wounds or incisions encountered. It can be removed with minimal discomfort despite blood crusting over it during the first wound inspection. This is especially important when managing wounds in children. Above this nonadherent tulle layer, we apply several layers of sterile gauze. Gauze is applied between the fingers to prevent webspace maceration. Avoid overstuffing webspaces with gauze; this can cause pain by compressing the digital nerves and compromising venous return. Care is taken to ensure that gauze is not applied circumferentially around the fingers or hand. Blood soaking and crusting around a circumferentially applied gauze can create a tourniquet effect and cause congestion distally. This is most crucial when caring for a replanted finger or a free flap transfer to the hand. The thumb is splinted in palmar abduction with the first webspace open. This is achieved by layering unfolded gauze into the palm to form a soft, sizable ball the thumb can rest on in mid-opposition.