Orthopedic Surgery for Hand Infections Treatment & Management

A few important guidelines assist in the management of hand infections.^[11] First, cellulitis must be treated with antibiotics. Most hand infections are caused by S aureus,^[8] and therefore, a first-generation cephalosporin (eg, cephalexin) is usually the first drug of choice. However, the potential exists for infections with different organisms. In fact, an increase in the incidence of community-acquired methicillin-resistant staphylococcal (MRSA) infections has been reported.^{[12, 13, 14, 15, 16, 17]}

Animal bites require bacterial coverage that is particular to the offending animal. Human bites require coverage for Eikenella corrodens; penicillin and a first-generation cephalosporin are appropriate choices in these cases. Cat bites require coverage for Pasteurella multocida^[18] ; appropriate antibiotics include IV ampicillin/sulbactam or oral amoxicillin clavulanate. Usually, oral antibiotics are sufficient as initial treatment. Many medical professionals recommend an initial, limited wound irrigation in the emergency department or in the outpatient clinic. Consider IV antibiotics in patients in whom cellulitis fails to resolve with oral antibiotics. In all cases, the final antibiotic coverage should be guided by culture and sensitivity results. Patients with a history of immunocompromise (including those with diabetes) should initially be treated with IV antibiotics.

Fungal infections can occur in or under the skin. Cutaneous fungal infections, or tinea, are treated with topical agents such as miconazole or clotrimazole. The most common subcutaneous infection is sporotrichosis; this condition can appear with an ulcerative lesion, along with lymphadenopathy. Gardeners are most commonly infected. Oral itraconazole for 3-6 months is the current recommended course of treatment. Fungal abscesses or disseminated fungal infections can occur and are usually found in immunocompromised patients.^[5]

As a rule, all abscess cavities must be drained. Antibiotics alone are not effective in treating pus. If the patient does not improve with antibiotics, suspect undrained pus or a foreign body. Immunocompromised patients should always receive IV antibiotics.

Before surgery, obtain a thorough patient history, and perform a thorough physical examination. The operating surgeon must counsel each patient about the appropriate risks and benefits of each procedure. Furthermore, consent for sufficient latitude in performing the procedure (eg, possible amputation) is necessary. Patients should always be preoperatively informed that further operations may be necessary.

In the operating room, perform all explorations and debridements under tourniquet control. The extremity should be exsanguinated by gravity. Obtain wound cultures before the administration of antibiotics; then administer a dose of perioperative antibiotics because of the likelihood of a transient bacteremia after debridement.

Intraoperative cultures should include tests for aerobic, anaerobic, fungal, mycobacterial, and atypical mycobacterial organisms. Debride all devitalized tissue, and thoroughly irrigate all wounds. Treat larger wounds with pulse lavage and antibiotic irrigation. A repeat exploration and a second operative irrigation and debridement are necessary for certain wounds.

Flexor tenosynovitis

At the time of the operation, an incision is made in the distal area of the palm over the proximal end of the flexor sheath. The sheath is incised, and the presence of cloudy fluid or pus in the sheath is a clear indication of tenosynovitis. A second midaxial incision is made distally in the digit to provide access to the distal end of the tendon sheath. An irrigation catheter is placed through the sheath, and continuous irrigation of the sheath (usually with saline or antibiotic solution) is performed for 48 hours.

Be cognizant of the presence of digital swelling due to overly aggressive irrigation. It is possible to cause digital necrosis. If signs of infection have improved, the drainage system can be removed, and the patient should receive a course of antibiotics with elevation of the affected area.

Deep palm and web-space infections

The incision should be centered over the area of fluctuance. Incisions can be made along the palmar creases when possible. In the case of deep-space infections, wide exposure is important. The palmar fascia is incised, and the common digital nerves and vessels should be identified and protected when possible. A palmar and dorsal incision may be necessary, particularly in the case of collar button abscesses.

Septic arthritis

Arthrotomy is necessary to adequately treat septic arthritis. For the MCP joint, a dorsal incision can be used. The extensor mechanism is split in the midline, and the joint capsule is incised. In the case of proximal IP joint infections, a dorsal incision can be used, but when dividing the extensor tendon, one must be careful to preserve the central slip. Alternatively, a midaxial incision can be made. The joint is entered by incision of the accessory collateral ligament.

The joint space must be copiously irrigated, and the fibrinous and synovial debris is debrided. The wound can be packed to allow for continuous bedside irrigation, or if joint debridement has been adequate, the wound can be loosely closed.

Osteomyelitis

In cases of chronic osteomyelitis, surgical debridement is required. The sequestrum or devitalized bone must be removed. Similarly, in cases of acute osteomyelitis, debridement of the denuded bone is important for obtaining microbiologic cultures and for treatment. Once acute and chronic infections have been resolved, bony reconstruction may be necessary.

Immobilization, with splinting of the hand in the position of safety (wrist extension of 15-30°, MCP flexion of 70-90°, and IP extension), is important in reducing joint contractures. Furthermore, elevation is a critical aspect of hand infection management. Often, adequate elevation and immobilization require the patient's hospitalization. Once the infection resolves, patients should begin early mobilization therapy. The patient should begin range-of-motion exercises and be seen by a hand therapist as soon as possible to minimize postinfection stiffness.

Patients require close follow-up for the first several weeks after the infection. The surgeon should remain vigilant for any recurrence of infection and for appropriate compliance with wound care and hand therapy.

Most complications from hand infections result from inadequate treatment. Inadequacies in treatment can be life-threatening in patients who are immunocompromised.^[1] Joint contracture from prolonged immobilization can be functionally devastating.

Recurrent infections or polymicrobial infection of the hand frequently complicates the care of the immunocompromised patient.^{[1, 12, 19]}

Once the infection resolves, aggressive hand therapy regimens should be started. Swelling from the infection itself and prolonged immobilization lead to the significant formation of adhesions and joint stiffness. Encourage patients not to guard their hands but, rather, to use them as much as possible. This step is particularly crucial if the patient has undergone surgical debridement, including treatment for tenosynovitis. If the hand infection has been treated appropriately with measures such as eradication of the abscess and devitalized tissue, the risk of recurrence is minimal. Certain infections (eg, herpetic whitlow), however, have a 20% recurrence risk.

Hand infections will remain to be a routine problem encountered by emergency physicians, primary care physicians, and hand specialists.^[8] The basic principles of management outlined in this article will continue to be crucial to successful treatment. The clinician needs to be aware of the increasing incidence of infections with more virulent microorganisms.^[13] Community-acquired infections with MRSA are encountered in nearly every area of the body, and the hand is no exception.^{[14, 15]} In addition, with the growing number of cancer survivors, transplant patients, and patients living with the human immunodeficiency virus (HIV), the surgeon can anticipate treating more complex polymicrobial hand infections.