hand infections

Hand Infections

Hand InfectionsIntroduction

In the pre-antibiotic era: 65% of hand disability resulted from minor injuries that became

infected 50 - 75% of all hand deformities were the result of infection

Kanavel’s study of the surgical anatomy of the hand: defined anatomical planes and channels careful placement of incisions for optimal drainage became the cornerstone of treatment in the pre-antibiotic era

Penicillin changed the landscape: severe hand infections are relatively uncommon today incidence stable since 1940’s

Hand InfectionsAntibiotics

valuable adjunct in infections but used alone will effect a cure in only a limited number of situations early diagnosis: 24 - 48 hrs. high dose IV therapy elevation & splinting to rest the affected part

Beyond this time success is unlikely: thrombosis of small vessels swelling & pressure within closed anatomical spaces

Abx need not be continued more than 7 - 10 days exception: osteomyelitis can usually switch to oral route in 2 - 3 days (if improving)

Hand InfectionsOutline

Principles High Risk Patients Felons & Paronychia Flexor Tenosynovitis Deep Space Infections Bites IDU Osteomyelitis Septic Arthritis Chronic Infections

Hand InfectionsIntroduction

Treatment principles early & adequate decompression of pus to avoid soft

tissue loss proper placement of incisions

avoids damage to adjacent structures minimizes scar contracture

appropriate debridement of necrotic tissue judicious splinting & early mobilization to minimize joint

stiffness appropriate use of Abx as adjunct to prevent

dissemination of established infection

Hand Infections Introduction

For infections requiring drainage, pre-operative planning is required. Type & placement of incision should:

Allow direct access to the abscess cavity

Permit easy extension in any direction

Follow accepted principles of hand surgery

Hand Infections Introduction

Principles: carry out procedure with optimal lighting, positioning,

visualization, analgesia & tourniquet control Do not exsanguinate part as this may cause bacterial seeding

incisions don’t cross flexion creases at > 45° avoid injury to vessels, nerves & tendons avoid compromising the blood supply to adjacent area avoid leaving a sensitive scar, especially in an important

tactile area wounds left open are packed for 48 - 72 hrs. followed by

saline soaks & exercise

Hand InfectionsHigh Risk Patient

Up to 50% of hand infections involve: Diabetic / Immune compromised IDU Bites

Higher risk for developing severe complications: Joint stiffness - Osteomyelitis Contracture - Necrotizing Fasciitis Amputation - Death

Felons & ParonychiaGeneral

Account for ~ 1/3 of hand infections

Felons Anatomy of the fingertip

Distal phalanx is a closed sac separate from the remainder of the digit Closed pulp space divided into a latticework by multiple septa Interstices filled with eccrine glands & fat Dorsum is rigid (bound by DP & perionychium)

An increase in pressure of this compartment can adversely affect the blood supply to the soft tissue & bone.

Felons

palmar closed-space infection of the distal pulp severe pain, redness & swelling Hx of minor penetrating trauma is usually present:

Minor cuts Splinters Glass slivers

most frequent causative agent: S. Aureus untreated felons can:

extend toward the phalanx --> osteomyelitis toward the skin --> draining sinus obliterate vessels ---> skin slough or necrosis supperative flexor tenosynovitis or septic arthritis of the DIPJ

FelonsTreatment

If recognized early (mild cellulitis): soaks & Abx Later (abscess formation): surgical drainage

Usually process has been going on > 48 hrs.

Principles: Avoid injury to n/v structures Utilize an incision that won’t leave a disabling scar Do not violate flexor sheath (stay distal) Produce adequate drainage

FelonsTreatment

Multiple incisions described: Fishmouth

J or hockey stick

Through & through

Volar transverse

Midvolar longitudinal

Unilateral high midlateral

Poor choices:

- painful scar

- unstable tip

- anaesthetic tip

Risks injury to digital nerve

FelonsTreatment

Palmar incisions through the center of the pulp Avoid crossing the DIP flexion crease (contracture) Blade should only penetrate the dermis to avoid n/v structures and

then a clamp is used to spread the subcutaneous tissue typically, drain over area of maximal tenderness or sinus Disadv:: scar over tactile surface, risk injury to dig. nerve

FelonsTreatment

Unilateral longitudinal Incision Best approach for most felons Incise on lateral aspect of digit 5mm dorsal & distal to the DIP flexion

crease Continue distally to a point 5mm away from the edge of the free nail Deepen the incision with a clamp within a plane just volar to the

palmar cortex of the DP

Location of Incisions:Index, middle & ring: ULNAR SIDEThumb & small: RADIAL SIDE

ParonychiaAnatomy

Paronychia

infection in and around the nail fold Acute: any break in the seal between the nail and nail fold

may serve as a portal of entry for infection hangnails manicures nail biting

usual causative agent: S. Aureus in more advanced infections, pus may accumulate beneath the nail plate,

separating it from the underlying nail bed. This infection involves the entire eponychium and is called an “eponychia”

Pus can also spread around the nail fold resulting in a “runaround infection”

ParonychiaTreatment

If recognized early (mild cellulitis): soaks & Abx Larger infections: drainage through the nail fold Paronychial fold & portion of adjacent eponychium:

Remove 1/4 of nail If this doesn’t allow drainage, incise fold away from matrix

ParonychiaTreatment

Eponychia: Elevate eponychial fold and excise prox 1/3 of nail Lateral (paronychial) incisions may aid in separating the nail base if

not already separated

Chronic Paronychia

Slightly different disease process with an indolent course marked by exacerbations & remissions

Etiology: proximal nail fold obstruction + fungal infection Often seen in people whose hands are constantly in a moist

environment Inflammation of the eponychial fold, often with separation

from the underlying nail and intermittent drainage usual causative agent: fungus > gram negative bacteria Tx: eponychial marsupialization + topical antifungal

Crescent-shaped piece of skin excised proximal to nail fold medical tx alone is largely unsuccessful

TenosynovitisAnatomy

Flexor sheaths are closed spaces Extend from the mid-palmar crease

to the DIPJ (Prox edge of A1 pulley to distal edge of A5 pulley)

Flexor sheath of small finger is continuous proximally with the Ulnar Bursa, while the sheath of the thumb is continuous with the Radial Bursa

Radial & Ulnar bursae extend proximal to the TCL and connect with the Parona space(Potential space between FDP & PQ muscle)

TenosynovitisGeneral

Flexor sheath infections most often as a result of penetrating trauma More likely at joint flexion creases Sheaths are separated from skin by only a small amount of

subcutaneous tissue here

Also, Felons can rupture into the distal flexor sheath Usual causative agent: S. Aureus most commonly affected digits:

Ring, long & index fingers

TenosynovitisGeneral

Purulence within the sheath destroys the gliding mechanism, rapidly creating adhesions that lead to loss of function

destroys the blood supply producing tendon necrosis

TenosynovitisClinical

Kanavel’s 4 cardinal signs:

Tenderness over & limited to the flexor sheath Symmetrical enlargement of the digit (“fusiform”) Severe pain on passive extension of the finger (> proximally) Flexed posture of the involved digit

Not all four signs may be present early on Most reliable sign: pain w. passive extension Cellulitis of the hand may appear similar, but swelling &

tenderness is not usually isolated to a single digit

TenosynovitisTreatment

Early infection < 48 hrs (& usually lacking all 4 signs) may initially be treated with IV Abx, splinting & elevation Failure to respond within 24 hrs. should necessitate drainage

Established pyogenic tenosynovitis is a surgical emergency Requires prompt surgical drainage Delays may result in tendon

&/or skin necrosis


2 basic approaches: Open vs. Closed

Open drainage: Decompression of the entire tendon

sheath via mid-axial & palmar incisions Wounds are left open to drain & heal

secondarily Rehab is prolonged; permanent finger

stiffness not infrequent Most useful for advanced cases where

resection of necrotic tendon is required


Closed tendon-sheath irrigation: 2 incisions made Proximal palm: open the sheath proximal to the A1 pulley Distal mid-axial: open sheath distal to the A4 pulley

Long irrigation catheter (16 - 18g) is placed in the proximal sheath with a drain left in the distal incision

Incisions are then closed, and sheath is irrigated for 48 - 72 hrs. May use NS or Abx solution (continuous drip or q2h flush) Addition of marcaine alleviates pain of irrigation

Modification involves multiple transverse incisions of cruciate pulleys with insertion of silastic drains


These incisions: ensure adequate drainage heal quickly Do not interfere with rehab

After removal of catheter and drains begin gentle passive & active ROM

Chronic Tenosynovitis

Unusual cases may be seen which present differently than acute pyogenic infections: Chronic swelling of the flexor sheath No disabling pain or loss of function

These are chronic infections most frequently caused by mycobacteria usually the result of a puncture wound in an aquatic environment M. Kansasii or M. Marinarum

Dx: AFB stains & culture of synovium Tx: tenosynovectomy + antituberculous drugs (6 - 24 mo)

Deep Space Infections

4 deep spaces clinically significant in hand infections: Subfascial palmar space Dorsal subaponeurotic space Thenar space Midpalmar space

Deep Space InfectionsSubfascial Palmar Space Infections

subfascial palmar space communicates with the dorsal subcutaneous space via web spaces between the digits

usually spread dorsally (“collar button abscess”) Double abscess: +/- palmar & dorsal abscesses connected through

hole in fascia Palmar spread is limited by the relationship of fascia to skin

Causes: Fissure in the skin between the fingers Distal palmar callus (MC head) Extension from subcutaneous infection in proximal finger

Severe distal palmar swelling with an abducted finger Puss-filled web spaces

Subfascial Palmar Space InfectionsTreatment

2 important points: Do not incise web space transversely Be alert for the double abscess configuration

Drainage is via a palmar approach with division of the palmar fascia to expose both the volar & dorsal compartments

Deep Space InfectionsDorsal Subaponeurotic Space Infections

DSS is beneath the extensor tendons on the dorsum of the hand

Often the result of penetrating trauma IDU’s neglected human bites

Dorsal swelling, erythema & tenderness + history make the diagnosis

Drain via linear incisions over the 2nd & 4th MC’s while preserving soft tissue coverage over the tendons occasionally direct incision over a pointing abscess is necessary Risks exposure (desiccation) of extensor tendons

Deep Space InfectionsThenar Space Infections

Thenar space follows the direction of Adductor Pollicis:

Dorsal: AP muscle

Volar: index flexor & 1st lumbrical

Radial: insertion of AP (proximal phalanx of the thumb)

Ulnar: oblique septum from skin to the 3rd MC

Thenar Space InfectionsClinical

Causes: penetrating injury thumb or index subcutaneous abscess thumb or index flexor tenosynovitis extension from radial bursa or

midpalmar space marked swelling of the thenar

eminence & 1st web space thumb forced into abduction severe pain with extention or opposition infection tracks dorsally via 1st web space,

over the AP & 1st dorsal interosseous muscles.

Thenar Space InfectionsTreatment

Drain via volar or dorsal incisions in the 1st web space or both: Identify neurovascular structures unroof the adductor fascia to open

the abscess cavity irrigate & debride catheter in volar incision & close;

penrose in dorsal incision & close compressive dressing & plaster splint

Deep Space InfectionsMidpalmar Space Infections

Boundaries: Dorsal: intrinsic muscles Volar: flexor tendons Radial: oblique septum from

the skin to the 3rd MC Ulnar: hypothenar muscles Distal: vertical septa of palmar fascia Prox: fascial layer at distal carpal tunnel

Deep Space InfectionsMidpalmar Space Infections

Clinical: usually due to direct penetrating trauma, rupture of tenosynovitis loss of palmar concavity, dorsal swelling, tenderness volarly

Midpalmar Space InfectionsTreatment

Drain via wide palmar incisions with +/- resection of palmar fascia to ensure drainage of abscess cavity.

or may place irrigation catheter & drain and close primarily.

Bursal Infections

Usually due to spread of flexor tenosynovitis from thumb or small finger

Radial bursa: Proximal extension of

tendon sheath of FPL extends through the carpal

tunnel into the distal forearm

Ulnar bursa: Proximal extension of tendon

sheath of FDP of small finger

Bursal InfectionsTreatment

Closed irrigation using 2 incisions, a catheter & a drain as previously outlined.

Human Bites

Often undertreated & misdiagnosed leading to significant morbidity

The most serious form of human bite infection is the clenched fist injury:

Any laceration over the head of a metacarpal is a human bite injury until proven otherwise

Human Bites

The wound that results from a punch to the mouth may appear insignificant and treatment may not be sought for days.

It often results in immediate inoculation of the subcutaneous tissue, the subtendinous space and the MCP joint with saliva Human saliva may contain over 108 microorganisms per ml. Over 42 species of bacteria identified Thus: Polymicrobial infection is the rule

Common organisms: S. Aureus, Strep sp., Eikenella: gram neg facultative anaerobe in ~ 30% (incr. severity)

Human Bites

Delay in onset of treatment is directly proportional to poor outcomes: In general, human bites treated within 24 hrs. rarely have serious

complications

in E.D.: Debride, irrigate, pack open Abx to cover gram +’s & eikenella (Pen & Ceph) +/- admission to follow response

To O.R.: Established joint space penetration, & more severe infections

Animal Bites

Dog more common than cat (5%) Cat bites are particularly virulent & can result in deep puncture

wounds that are hard to clean

More than half involve kids Basic principles of debridement & irrigation apply

Deep puncture wounds are left open & may require extension Established infections are debrided & packed open Superficial lacerations may be loosely closed after irrigation

Common organisms: S. Aureus, Strep viridans, Pasturella (#1 in cats), anaerobes

Abx: ampicillin (Clavulin on outpatient basis)

Injection Drug Use

Common sites of infection: Dorsum of hand Radiodorsal area of the wrist Palmar aspect of the forearm Dorsum of the fingers at the PIPJ

Clinical spectrum: Cellulitis Subcutaneous abscess Flexor tenosynovitis Septic joints Osteomyelitis Necrotizing fasciitis

Injection Drug Use

Source of infection from a variety of sources Skin Saliva Bowel

Tx: Admission elevation of limb broad spectrum IV Abx analgesia (may need support from APS or CDRT) +/- debridement & irrigation Medicine consult

Hand InfectionsOsteomyelitis

Almost always the result of adjacent spread wound infection joint infection tenosynovial infection

Also, direct penetration (hematogenous spread is rare)

most commonly S. Aureus Bone necrosis: hallmark

microorganisms reside in dead bone

If caught early, before extensive bone necrosis occurs, it may be cured with Abx alone.

Osteomyelitis Diagnosis

Xrays: Early radiographs may be normal It takes at least 10 days for matrix

to mineralize & areas of increased density to be detected.

Lytic lesions; sclerosis (1 month)

Bone Scan: Can pick up osteomyelitis early, but less specific

Prompt surgical exploration is the most reliable way to establish the diagnosis

Osteomyelitis Treatment

Approach depends on location of involved bone: Phalanx: mid-axial incision Metacarpals: dorsal approach

all infected bone must be removed Soft bone may be curetted may need to use drill holes to remove a small window of cortical bone

for decompression of the infection routine post-Op care or may also use constant irrigation

methods (1 wk) severe, extensive involvement of a digit may be best treated

by amputation Will prevent stiffness & major disability of the uninfected parts

Hand InfectionsSeptic Arthritis

usually the result of penetrating trauma: bite or tooth wound

also, spread from soft tissue or bony infection joint is swollen, warm & tender

pain with axial loading passive motion is restricted & painful

Xrays: thinning of joint (cartilagenous loss) resorption of subchondral bone osteomyelitis (late)

aspiration of joint for C & S

Septic ArthritisTreatment

Drainage is imperative as soon as the diagnosis is made Destruction of the articular cartilage by lysozymal activity

approach is through a longitudinal dorsolateral incision over the affected joint

access to the joint is via an incision dorsal to the cord portion of the collateral ligament

joint is irrigated & debrided packed open for 48 - 72 hrs. (or closed over irrigation)

packing removed and gentle ROM begun wound granulates closed

Hand InfectionsChronic Infections

Atypical mycobacterium infections: penetrating wound often in a marine environment prolonged, relatively non-painful swelling of finger, palm or wrist Tuberculous & atypical mycobacteria have a predilection for synovial

tissue of joints & tendon sheaths Tenosynovium is thick, infected & hypertrophic. It surrounds the

tendons & erodes the pulleys. Dx: culture synovial biopsy

Noncaseating granulomas & AFB Tx: thorough joint synovectomy

For ++ joint damage: rest the joint until the infection is cured before undertaking reconstruction

For tenosynovium: complete synovectomy sparing the pulleys Start anti-TB meds empirically (around time of synovectomy)


Tuberculous Infections: less common now than several decades ago Presents in a similar manner as atypical mycobacterial

infections Tx: as above, synovectomy + anti-TB drugs In addition, can produce a dactylitis

Enlarged fingers Proliferation of subperiosteal reaction on Xray

Tx: surgical excision & curettage of the involved areas


Leprosy: M. lepraemurium Predilection for cooler areas of the body including the hands Most frequently produces a neuropathy involving the ulnar nerve:

intrinsic atrophy clawing weakness in pinch

Tx: surgical procedures limited to reconstruction for the neurological deficits


Fungal Infections: except for biopsy for diagnostic purposes, surgical treatment is rarely

necessary best treated with systemic &/or local anti-fungal agents occasionally a tenosynovitis, septic arthritis or osteomyelitis is seen:

Appropriate debridement required as above Mainstay is still anti-fungal agent

Post Op Care

Wound care & early initiation of therapy are key in achieving good functional results in treating hand infections

In general: wounds are debrided, irrigated & packed open packing usually removed 24 - 48 hrs. post-op initiation of regular wound cleansing gentle active ROM splints may be helpful in enhancing joint motions early involvement of a hand therapist is important in achieving a good

functional result.

hand infections

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