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HAND INFECTIONS
8TH MAY 2016Mentor: Dr Dinesh
Presented by: R. Nandinii
OVERVIEW:◦Paronychia◦Felon◦Pyogenic flexor tenosynovitis◦Deep space infections◦Human bite◦Animal bite◦Take home messages
Anatomy
Paronychia◦Infection of the lateral nail fold◦If Infection extends to the
eponychium (defined as the thin membrane distal to the nail wall at the base of the nail), it is properly termed an eponychia. ◦When infection involves both
lateral nail folds and eponychium, it is called a run-around infection
◦In adults, Staphylococcus aureus is the most common pathogen
◦Pathophysiology ◦Infection occurs when there is violation of the seal between the nail
plate and nail fold, allowing the inoculation of bacteria.
◦Risk Factors◦Hangnails, ◦Manicures, ◦Penetrating trauma, ◦Constant exposure to a wet or moist environment, ◦Nail biting or sucking
Initial swelling, erythema, tenderness
with progression
to fluctuance, and abscess
formation are typical.
Spontaneous decompression can occur,
including tracking
beneath the nail plate
(subungual abscess).
Deeper infections can
involve the nailbed, pulp
space, and bone,
producing nailbed
destruction, felon, or
osteomyelitis
Clinical presentation
Treatment◦Early stage
◦Oral antibiotics,◦Warm soaks◦Rest and observation
◦Surgical decompression is the treatment of choice◦Decompression is performed by carefully entering the abscess cavity
between the nail plate and nail fold with a scalpel blade .
◦A small wick is placed for 24 to 48 hours to prevent the incision from closing and recurrence of the infection. The wick is removed, and saline warm soaks are begun
A: An infected lateral and proximal nail fold can be elevated by an elevator or scalpel. B: For extensive infections, a relief incision(s) is made perpendicular to the edge of the nail fold to allow for removal of a portion or all of the nail plate. (Reprinted from Seiler JG. Essentials of hand surgery . Philadelphia: Lippincott Williams & Wilkins, 2002, with permission. Copyright American Society of Surgery of the Hand.)
Depending on the extent of the infection, a partial or complete nail plate removal with or without lateral nail fold relief incision(s) is performed.
The incision should be made perpendicular to the edge of the nail fold.
A single or double incision is used depending on the location of the infection
Subungual abscesses are treated with removal of a portion of or the entire nail. The abscess is carefully debrided while protecting the sterile and germinal matrices
(A) Elevation of the eponychial fold with flat probe to expose the base of the nail. (B) Placement of an incision to drain the paronychium and to elevate the eponychial fold for excision of the proximal one-third of the nail. (C-E) Incisions and procedure for elevating the entire eponychial fold with excision of the proximal one-third of the nail. A gauze pack prevents premature closure of the cavity.
◦Chronic paronychia◦Chronic paronychia occurs more commonly in individuals constantly exposed to moist environments.
◦Infections may be intermittent; clinically, the eponichial fold is thickened and painful
◦Candida albicans is a frequent offending organism
◦Topical antifungal ointments are generally used 4 to 6 weeks.FIGURE 2. Eponychial marsupialization is performed by removing a small, crescent-
shaped portion of the eponychial fold proximal to the distal edge of the eponychial fold. Care is taken to not injure the underlying germinal matrix. (Reprinted from Seiler JG. Essentials of hand surgery . Philadelphia: Lippincott Williams & Wilkins, 2002, with permission. Copyright American Society of Surgery of the Hand.)
Felon◦A felon is a deep space infection or abscess
of the distal pulp of the finger or thumb.
◦It differs from the superficial apical infection involving the distal portion of the pulp skin, which often responds to a small, deroofing incision
◦The organism most frequently cultured from a pulp space infection is S. Aureus
Felon Pathophysiology◦Infection typically is due to direct inoculation of
bacteria by penetrating trauma but may be caused by◦ hematogenous spread ◦ local spread from an untreated paronychia.
◦Most common in thumb and index finger.
Clinical presentation◦Throbbing pain and◦Tense swelling localized to the pulp
Felon“Don’t wait for fluctuation if tension is
severe”◦Infection results in edema increased pressure within the closed
compartment impaired venous outflow local compartment syndrome
◦Untreated felons can: extend toward the phalanx --> osteomyelitis toward the skin --> draining sinus obliterate vessels ---> skin slough or necrosis suppurative flexor tenosynovitis or septic arthritis of the DIPJ
Treatment If recognized early (mild cellulitis): soaks & AbxLater (abscess formation): surgical drainage
Usually process has been going on > 48 hrs.
Principles:Avoid injury to nerve and vessel structuresUtilize an incision that won’t leave a disabling scarDo not violate flexor sheath (stay distal)Produce adequate drainage
• The best is a longitudinal incision over the area of greatest fluctuance because it avoids– Skin slough– Digital nerve injury – Creation of an unstable fat pad
• To avoid penetration of the tendon sheath, the incision should not extend to the distal interphalangeal crease. 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 DPLocation of Incisions:
Index, middle & ring: ULNAR SIDEThumb & small: RADIAL SIDE
Additional measures◦Pus should be taken for C&S
◦Initial empiric antibiotic coverage with a second-generation cephalosporin, such as cefazolin, while awaiting culture identification and sensitivity is usually adequate.
◦Addition of gram-negative coverage is recommended in an immunocompromised individual.
◦Postoperative wound care, edema control, splinting, and motion optimization are preferably pursued with therapy supervision
Pyogenic flexor 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)
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 fingersPurulence within the sheath destroys the gliding mechanism, rapidly creating adhesions that lead to loss of function
Destroys the blood supply producing tendon necrosis
ClinicalKanavel’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 onMost reliable sign: pain w. passive extension
Cellulitis of the hand may appear similar, but swelling & tenderness is not usually isolated to a single digit
Treatment
Early infection < 48 hrs (& usually lacking all 4 signs) may initially be treated with IV Abx, splinting & elevationFailure to respond within 24 hrs. should necessitate drainage
Established pyogenic tenosynovitis is a surgical emergencyRequires prompt surgical drainageDelays may result in tendon &/or skin necrosis
Treatment2 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
Treatment
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
Chronic TenosynovitisUnusual 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 synoviumTx: tenosynovectomy + antituberculous drugs (6 - 24 mo)
Deep Space Infections4 deep spaces clinically significant in hand infections:
Subfascial palmar spaceDorsal subaponeurotic spaceThenar spaceMidpalmar 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 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 InfectionsTreatmentClosed irrigation using 2 incisions, a catheter & a drain as previously outlined.
Human BitesOften 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 BitesThe 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 BitesDelay 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 BitesDog 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 kidsBasic 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)
Take home messages:Not all hand
swellings are
cellulitis
PFT is a surgical
emergency
Remember 4
Kanavel’s sign
If swelling doesn’t
subside in 24h…I&D
Most common organism
Staph Aureus
THE END