Surgical Management of Hand Infections

Introduction:

Hand infections are the most common clinical presentations to the emergency department, which often need admission for intravenous antibiotics and surgical intervention. Hand infections are associated with severe signs of inflammation and often result from trauma, animal bites, human bites, or contaminated lacerations. The infections are mainly related to pre-existing co-morbidities that hamper immune response, like diabetes mellitus, current smokers, and HIV (human immunodeficiency virus) patients.

The most common pathogen responsible for hand infection is Staphylococcus aureus or Streptococcus, which can damage local structures and cause loss of function. Hand surgery is a broad term that encompasses different types of procedures. At the same time, hand reconstructive surgery focuses on restoring the hand's standard functionality and anatomical aspect. It is required in the following cases:

• Hand injuries.

• Rheumatic diseases, like osteoarthritis and rheumatoid arthritis.

• Degenerative changes to the structures in hand.

• Congenital disabilities of the hand.

• Infections of the hand.

What Are the Different Types of Hand Infections?

The article highlights the most commonly occurring hand infections:

• Paronychia: Paronychia is the most common infection that involves the perionychium, the soft tissue fold around the nail plate. This happens due to nail biting or sucking, contaminating the oral flora. It is also believed that previous trauma or wounds that disturb the perionychium are a key cause of infection. The distinctive appearance is connected to pus that forms a horseshoe-shaped pattern along the perionychium. It produces an abscess at the skin-nail plate junction, causing swelling, inflammation, and tenderness at the fingertip. In addition, there can be subungual (under the nail bed) pus collection. If left untreated, this can cause nail bed necrosis and osteomyelitis of the distal phalanx. Therefore, a treatment outline comprising antibiotics, incision, and drainage of the pus is enough to remove the nail plate. In addition, it's advised to wash with normal saline and an antibacterial solution while changing the bandage often.

• Infectious Tenosynovitis: Tenosynovitis is inflammation of the tendon sheath and often arises from direct bacterial inoculation, mainly with Staphylococcus aureus is secondary to infiltrating trauma. The most common tenosynovitis is flexor sheath infections. The infection progresses to a surgical emergency because the increasing tendon sheath pressure may impair blood flow, eventually causing tendon necrosis (death) and rupture. Infectious tenosynovitis can result from hematogenous or direct bloodstream dissemination from a felon (infection in the closed space of the fingertip), septic joints, or deep space infections. Kanavel's signs are strong indicators of flexor sheath infection:

• Tenderness along the flexor sheath.

• Flexed finger posture.

• Pain on passive extension.

• Fusiform swelling of the affected digit.

• Felon Infections: An illness known as a felon is a subcutaneous infection of the fingertip pulp that is mostly brought on by the pathogen S Aureus and is brought on by direct contact with splinters or garden thorns. The thumb or index finger is where they most frequently occur because fibrous vertical septae (muscle strands) connect the periosteum (membrane consisting of veins and nerve covering the ostia or bone) to the pulp's epidermis (outer layer of skin), creating a closed system of microcompartments that are vulnerable to rising pressure from inflammation. This inflammation manifests as swelling of the pulp distal to the distal phalangeal crease with excruciating pain. Most patients have a moderate degree of infection when they first arrive, and medications help hasten recovery.

• Deep Space Infections: The thenar, mid-palmar, and hypothenar areas are included in the hand's deep spaces. When these spaces get infected, the respective area portrays all signs of inflammation like swollen, tender, and erythematous, with limited hand movements.

What Are the Various Types of Hand Surgery?

The treatment for hand infection is based on three principles:

Surgical Treatment:

• Surgical Drainage or Debridement: Sore or abscess in the hand is drained surgically to remove any pus, followed by debridement used to sweep necrosed and contaminated tissue from the damaged area, which prevents further infection and helps promote healing.

• Skin Grafts: Skin grafts for the hand mean substituting or affixing skin to the injured or missing hand skin, often done for fingertip amputations or injuries. Skin grafts take a portion of healthy skin from other body regions, called the donor site, and attach it to the damaged area to protect it and promote healing.

• Skin Flaps: Taking skin from a healthy portion of the body with its blood supply, fat, and muscles and transferring it to the damaged or injured part to promote blood supply and healing.

• Closed Reduction and Fixation: When there is a bone fracture, or broken bone, in the area of the hand, including the fingers. The surgery realigns the broken bone and retains it, immobilizing it while healing. The bone is immobilized using internal fixtures like wires, rods, splints, and casts.

• Tendon Repair: Tendons are fibers that bind muscle to bone. Tendon damage can occur due to infection, trauma, or sudden rupture.

• Nerve Repair: An injury can harm the nerves of the hand associated with loss of hand function and feeling.

• Fasciotomy: Compartment syndrome is a painful condition associated with swelling and increased pressure in the body's compartment (or small area of the hand), which interferes with blood flow to the body tissues. The condition destroys function and causes severe and increasing pain and muscle weakness. In fasciotomy, an incision is made in the hand or arm, decreasing the pressure, allowing the muscle tissue to swell, and restoring blood flow. The damaged tissue is removed at this time to allow better healing and for better infection resolution. In addition, this procedure helps prevent further damage and functional limitation in the affected hand.

• Joint Replacement: Arthroplasty involves replacing the hand joint affected by arthritis with a prosthetic joint. It is the go-to procedure in case of severe hand arthritis.

Adequate Antimicrobial Therapy: Early infectious conditions of the hand, like cellulitis and early paronychia, may be treated without surgery with antimicrobial treatment that must be pathogen-specific and not resistant to antimicrobial agents. Likewise, bite wounds are treated with beta-lactam antibiotics and beta-lactamase inhibitors. In addition, first and second-generation cephalosporins antibiotics cover staphylococci and streptococci. Infections with anaerobic and gas-producing bacteria are infrequent, especially in diabetic and immune-compromised individuals.

Early Physiotherapy: Achieving the basic functionality of the hand is mainly achieved through hand exercises.

Conclusion:

Due to the function, anatomy, and exposure to multiple pathogens, the hand is highly prone to infection, mainly due to post-traumatic conditions. Isolates from hand infection include Staphylococcus aureus and beta-hemolytic group A streptococci, pus-producing pathogens that require drainage as a treatment. Combined modality with surgery, antimicrobial therapy, and physiotherapy help restore functions and anatomy. Often underplayed and ignored, hand infection management plays a significant role in preventing further sequelae and aggravation.