Flexor tendons - enclosed by synovial sheaths. Tendons - blood supply through synovial folds known as vincula, each tendon having two, vincula longa and vincula brevia. The sheath of the little finger is continuous with the ulnar bursa covering the flexor tendons in the palm. The flexor pollicis longus is covered by a single sheath throughout, the radial bursa. Synovial sheaths can be infected producing tenosynovitis. Infection can spread throughout the sheath. Infection of the sheath of the little finger can thus spread up the distal aspect of the forearm into the space of Parona.

1. Infections of Hand
Dr. Mirant Dave

2. Factors Influencing
• Anatomic
• Local
• Systemic
• Bacterial Virulence
• Size of inoculum

3. Anatomical Factors
• Thin layer - skin and subcutaneous tissue
• Closed space - distal digital pulp
• Proximity of flexor tendon sheath - bone and joint
• Proximal extent of the flexor sheath into the palm, connecting with -
radial and ulnar bursae
• Location of the thenar and mid-palmar spaces in the hand and the
space of Parona proximal to the wrist near the flexor tendon sheaths.

5. Synovial Sheath
• Flexor tendons - enclosed by synovial sheaths.
• Tendons - blood supply through synovial folds known as vincula,
each tendon having two, vincula longa and vincula brevia.
• The sheath of the little finger is continuous with the ulnar bursa
covering the flexor tendons in the palm.
• The flexor pollicis longus is covered by a single sheath throughout,
the radial bursa.
• Synovial sheaths can be infected producing tenosynovitis. Infection
can spread throughout the sheath. Infection of the sheath of the little
finger can thus spread up the distal aspect of the forearm into the
space of Parona.

10. Local Factors
• Extent and nature of soft-tissue damage
• Amount and virulence of bacterial contamination
• Type and amount of foreign material present and persistent in the
wound.

11. Systemic Factors
• Malnutrition
• Alcoholism
• Intravenous drug abuse
• Diabetes mellitus
• Long-term use of corticosteroids and antitumor necrosis factor-α
medicines
• Immunosuppression following solid organ and bone marrow
transplant
• Infection with human immunodeficiency virus.

12. Paronychia
Infection usually is caused by the introduction of S. aureus into the soft-tissue fold
around the fingernail (eponychium) associated with a hangnail or poor nail hygiene.

14. Incision and Drainage
• When an abscess forms in the eponychial or paronychial fold, it
usually begins at one corner of the horny nail and travels under either
the eponychium or the nail toward the opposite side.
• If an abscess is on one side only, it should be incised, angling the knife
away from the nail to avoid cutting the nail bed, which would cause a
ridge later. If the abscess is under one corner of the nail root, this
corner should be removed.
• If it has already migrated to the opposite side and under the nail, a
second incision should be made there, the skin folded back
proximally, and the proximal one third of the nail excised. The wound
is loosely packed with iodoform gauze for 48 hours for drainage.

16. Chronic Paronychia
• Chronic paronychia typically occurs in patients whose activities
require prolonged exposure to water. With chronic inflammation and
recurring infection, the eponychium appears thickened and
prominent.
• Organisms obtained from the cultures of these lesions include
Staphylococcus pyogenes, S. epidermidis, Candida albicans, colonic
gram-negative bacteria, or a mixture of these.
• Methylprednisolone cured or improved 85% of the nails.

17. Eponychial Marsupialization
• Bednar and Lane found the eponychial marsupialization technique of
Keyser and Eaton to be effective in curing patients of chronic
paronychia. They further noted that if nail irregularities are present,
removing the nail leads to healing without recurrence.
• Excise a crescent of skin 3mm wide parallel to the eponychium and
extending from the radial to the ulnar borders.
• Cover the wound with petroleum/bismuth tribromophenate
impregnated gauze (Xeroform). If the nail is removed, place this gauze
beneath the nail fold.

18. PostOperative
• Soak the finger in hydrogen peroxide and to wash it with
chlorhexidine gluconate skin cleanser (Hibiclens) three times daily,
beginning on post- operative day 3.
• The daily washings are continued until all drainage stops. Antibiotics
should be continued for 2 weeks.

21. Felon
An abscess in the subcutaneous tissues of the distal pulp of a finger or thumb.

22. Felon
• The distal digital pulp is divided into tiny compartments by strong
fibrous septa that traverse it from skin to bone.
• A transverse fibrous curtain also is present at the distal flexor finger
crease. Because of these septa, any swelling causes immediate pain
that is intensified because of increased pressure within the pulp.
• Infection can be caused by a penetrating injury from a foreign body or
from “finger sticks” for medical reasons (e.g., hematocrit and blood
glucose determinations).

23. Felon
• Swelling, redness, and pain, typical of cellulitis, are present initially.
Abscess formation may follow rapidly.
• The pulp abscess (felon) can extend into the periosteum, around the
nail bed, or proximally through the fibrous curtain into the flexor
sheath or through the skin to the exterior over the pulp.
• Abscesses beginning deep, especially if untreated, penetrate the
periosteum and cause osteomyelitis; the more superficial ones cause
skin necrosis.
• Abscesses may form occasionally in the middle and proximal digital
pulps.

26. Incision and Drainage
• This incision must be accurate. Make the incision dorsal to the tactile
surface of the finger and not more than 3 mm from the distal free edge of
the nail; otherwise, the ends of the digital nerve would be painfully
damaged.
• Blunt dissection with the tip of a small pair of scissors or a mosquito
hemostat avoids sharp injury to nerve endings, allowing disruption of the
fibrous septa and adequate drainage.
• A J-shaped incision is sufficient; a fish mouth incision around the whole
fingertip is slow to heal and can result in painful scarring, especially if it is
placed too far palmarly.
• Irrigate the wound copiously and pack it with iodoform gauze or sterile
gauze bandage.

27. Subfascial Space Infections
The recognized deep spaces of the hand include the interdigital web spaces, the
mid-palmar space, the thenar space, a less well-defined hypothenar space, the
Parona space, and the dorsal subaponeurotic space.

29. Web Space Infection(Collar Button Abscess)
• Web space infection usually localizes in one of the three fat- filled
interdigital spaces just proximal to the superficial transverse ligament
at the level of the metacarpophalangeal joints.
• Typically in laborers. It may begin near the palmar surface, but
because the skin and fascia here are less yielding, it may localize to
drain dorsally.
• Here the tissue becomes obviously swollen, but the greater part of
the abscess remains nearer the palm. This may be the more
dangerous part because, unless drained, it may spread through the
lumbrical canal into the middle palmar space.

30. Web Space Infection
• Two longitudinal incisions usually are necessary for drainage: one on
the dorsal surface between the metacarpal heads and the other on
the palm, beginning distal to the distal palmar crease and curving
proximally.
• Crossing the palmar creases at right angles to the crease should be
avoided. The web should not be incised.

32. Dorsal Subaponeurotic Space
• Dorsal: extensor tendons
• Volar: metacarpals and interossei
• Presentation: Dorsal hand swelling
• Treatment: Longitudinal incisions over index and ring metacarpals,
not directly over extensor tendons

33. Thenar Space
• Dorsal: adductor pollicis
• Volar: index flexor tendons
• Ulnar: septum of Legueu and Juvara
• Radial: adductor pollicis insertion at P1 of thumb

34. Thenar Space
• Presentation: Thenar and first webspace swelling; thumb abduction
with painful adduction or opposition; pantaloons-shaped abscess if
involvement of first dorsal webspace through contiguous spread
• Treatment: Palmar, dorsal, or 2-incision approaches, abscess may
drain through dual incisions or single incision perpendicular to first
webspace to minimize webspace contracture

35. Mid-Palmar Space
• Dorsal: middle and ring finger metacarpals and second and third
interossei;
• Volar: flexor tendons and lumbricals;
• Ulnar: hypothenar muscles;
• Radial: septum of Legueu and Juvara

36. Mid-Palmar Space
• Presentation: Loss of normal palmar concavity with marked palm
tenderness, painful passive motion of middle and ring fingers;
substantial dorsal swelling may be present
• Treatment: Transverse incision in distal palmar crease; curvilinear
incision along thenar crease

37. Space of Parona
• Volar: pronator quadratus;
• Dorsal: digital flexor tendons;
• Ulnar: flexor carpi ulnaris;
• Radial: flexor pollicis longus

38. Space of Parona
• Presentation: Pain with passive finger flexion; acute carpal tunnel
syndrome may be present
• Treatment: Avoid placing incisions directly over flexor tendons or
median nerve to avoid desiccation.

41. Tenosynovitis
An infection within the flexor tendon sheath may be the result of the spread of
adjacent pulp infections or puncture wounds in the flexor creases.

42. Tenosynovitis
• Kanavel considered the four cardinal signs of suppurative
tenosynovitis,
• tenderness over the involved sheath,
• rigid positioning of the finger in flexion,
• pain on attempts to hyperextend the fingers,
• swelling of the involved part
• With persistent tenosynovial infection, pressures within the flexor
sheath can exceed 30 mm Hg, rendering the tendons ischemic in the
presence of infection.

43. Irrigation
• Closed postoperative irrigation is appropriate and effective for infections
that yield serous exudate or purulent fluid on opening the flexor sheath
and for infections that are relatively acute. Some have found that closed
catheter irrigation is as effective as open drainage of pyogenic flexor
tenosynovitis.
• Chung and Foo modified the closed irrigation technique by introducing an
intraluminal 24-gauge wire to stiffen the catheter for easier cannulation
and manipulation; they also fenestrated the catheter along its middle
portion to increase the turbulence of intrathecal flow.
• Jing and Iyer described the use of a metal ear suction catheter for
irrigation of a flexor tendon sheath infection, citing ease of insertion under
direct vision, effectiveness, and low cost among its advantages. If the
infection is chronic, or if the flexor tendon is grossly necrotic, open
drainage may be necessary.

45. Infections of Radial
and Ulnar Bursae
• Horseshoe Abscess
• To drain the radial bursa, first
make a lateral incision along the
proximal phalanx of the thumb
and open the bursa at its distal
end.
• Open the ulnar bursa on the
ulnar side of the little finger and
again proximal to the wrist with
the help of a probe.

47. Septic Arthritis – Finger Joint Infection
• Involved joints usually are swollen, tender, and warm, and the finger
usually is held in slight flexion.
• The joint fluid WBC usually is greater than 50,000/mm3.
• Because septic arthritis can cause articular cartilage destruction and
osteomyelitis in the underlying phalanx, it should be treated as an
emergency when pus has been identified in the joint.
• OPEN DRAINAGE can be done.

48. Osteomyelitis
• Infection of the neighbouring soft tissues; an open fracture; the open
treatment of a closed fracture; and the consequences of peripheral
vascular disease, diabetes mellitus, and immunodeficiency states.
• Open drainage of pus and debridement of necrotic material provide
adequate material for culture and ensure decompression of the
abscesses.

49. Osteomyelitis
• Although salvage of the digits is possible with diaphysectomy,
sequestrectomy, external fixation, the use of antibiotic-impregnated
polymethyl methacrylate, and subsequent bone grafting, frequently it
is difficult to preserve a functioning digit and hand because of the
severe stiffness that develops in the involved digit and in the
remaining digits.
• Especially in adults, unless the infection can be controlled to preserve
satisfactory function in the involved digit and hand, amputation
should be considered.
• The amputation should be at the joint proximal to the involved bone.

50. Human Bite Infections
• Human bite injuries occur in two ways.
• The first is inadvertent and relatively innocent, involving nail biting
and similar activities.
• The second, although at times accidental, usually involves
intentionally violent attacks and includes the more common full-
thickness bites, bite amputations, and injuries related to striking a
tooth with the clenched fist.

52. Human Bite Infections
• Generally, all patients with small lacerations over the metacarpophalangeal
joint should be assumed to have tooth injuries, regardless of the history
given.
• Radiographs should be obtained to rule out fractures and foreign bodies,
and the wound should be explored to rule out intraarticular injury.
• Several authors have observed that patients who seek treatment less than
24 hours after injury usually do not have signs of sepsis, so joint
exploration, swabbing for cultures (aerobic and anaerobic with attention to
E. corrodens), treatment with antibiotics, and close observation usually are
sufficient. Some surgeons advise all patients who have sustained human
bites to be admitted to the hospital.

53. Human Bite Infections
• Patients who seek treatment 24 hours or more after injury may have
definite signs and symptoms of sepsis and may require open joint
drainage and irrigation, close observation (usually in the hospital),
and intravenous antibiotics.
• Patients presenting with bite infections more than 8 days after the
initial injury have been reported to have an 18% chance of requiring
amputation.

54. Animal Bite Infections
• Dog bites to the hand may appear as puncture wounds or as
superficial or deep lacerations.
• Canine oral flora include S. aureus, Streptococcus viridans,
Bacteroides, and Pasteurella multocida.
• Most of these organisms usually are sensitive to penicillin.
• Tetanus prophylaxis should be accompanied by the use of antibiotics
in healing dog bites.
• Deep wounds should be debrided, cleansed, irrigated, and left open
for secondary closure

55. Unusual Infections
• Herpetic Infections
• Necrotizing Fasciitis - Streptococcal infections
• Gas Gangrene – Clostridial Myonecrosis
• Mycobacterial Infections
• Fungal Infections
• Pyoderma Gangrenosum

56. Investigations
• WBC, C-reactive protein, ESR have limited role
• Gram stain, culture, and antibiotic sensitivity determinations
• Radionuclide scanning may show bone infection
• MRI and ultrasound may localize an abscess.

57. Organisms
• S. aureus. Typically, 80% or more of wounds cultured from swabs produce
multiple organisms, whereas tissue specimens may produce a single
causative organism in about 75%.
• Other organisms that commonly cause hand infections include
streptococci, enterobacteria, Pseudomonas, enterococci, and Bacteroides.
• Less common causes include the various mycobacteria, gonococcus,
Pasteurella multocida (in cat or dog bites), Eikenella corrodens (in human
bites), Aeromonas hydrophila from standing fresh water (e.g., ditches,
puddles, and ponds), Haemophilus influenzae (in children 2 months to 3
years old), a variety of anaerobic organisms (including clostridia), and other
rare bacteria, such as those that cause anthrax, erysipeloid, and brucellosis.

58. Incision and Drainage
• Use a general anesthetic or distant regional block because a local
anesthetic may not function in the septic environment, may spread
the infection, and add to an already swollen part.
• Use a tourniquet, but before inflating it, elevate the hand for 3 to 6
minutes to avoid limb exsanguination with an elastic wrap and the
potential for the proximal spread of the infection.
• After properly preparing and draping the area, make the incision for
drainage as described for specific infections.
• After making the skin incision, always spread the deeper structures
with blunt dissection to avoid injury to important nerves, vessels, and
tendons.

59. Incision and Drainage
• Although an incision for drainage relieves pain and reduces the spread of
infection, it also creates an open infected wound subject to further
contamination.
• Copious irrigation with a pulsatile irrigator is an effective way to decrease
contamination. Although wound closure after abscess drainage has been
advocated, it probably is safer to return to the operating room in 3 to 5 days and
close the wound secondarily, if the condition of the wound permits.
• If joints or flexor tendons have been exposed by skin necrosis, however, cover
them at once to preserve their vital functions. In most instances, leave the
wound open.
• Infections involving the tendon sheaths and joints usually result in some loss of
function. Such loss of function is seen less often in superficial infections, unless
surgical scars have adhered to adjacent structures, such as nerves or tendons

60. PostOperative Care
• Immediately after surgery, the hand is wrapped with bulky layers of
gauze to hold it in the position of function and to pad the wound.
• A metal, plaster, or fiberglass splint is applied to support the wrist in
about 30 degrees of extension, the metacarpophalangeal joints in
about 60 to 70 degrees of flexion, the interphalangeal joints in full
extension, and the thumb in a palmar abducted-opposed position.
• The hand is continuously elevated after surgery. Active motion of
digits is begun as soon as possible. Usually, the dressing is first
changed 24 to 48 hours after drainage and then is changed daily or
every other day. Moist dressings may help remove infected drainage.

61. Post-Operative Care
• Sterile technique during dressings to prevent further contamination.
• After several days, further debridement of necrotic material may be
necessary if the infection is extensive.
• As soon as drainage has ceased and healthy granulation tissue
appears, the wound is closed secondarily; a free skin graft or flap
coverage may be necessary, but usually only when a skin slough has
occurred.

62. Take Home Message
• A protocol of early, aggressive surgical incision and drainage
combined with intravenous antibiotic therapy should result in a
shorter hospital stay, faster healing, and fewer complications.
• Failure to recognize the polymicrobial nature of hand infections and
inadequate surgical debridement are frequent causes of poor results.
• The importance of adequate surgical treatment cannot be
overemphasized because antibiotics alone may be insufficient to
control the infection.