Hand Infections

2. Hand Infections

3. 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

4. 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)

5. Hand InfectionsOutline • Principles • High Risk Patients • Felons & Paronychia • Flexor Tenosynovitis • Deep Space Infections • Bites • IDU • Osteomyelitis • Septic Arthritis • Chronic Infections

6. 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

7. Hand InfectionsIntroduction • 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

8. Hand InfectionsIntroduction • 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

9. 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

10. Felons & ParonychiaGeneral Account for ~ 1/3 of hand infections

11. 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.

12. 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

13. 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

14. 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

15. 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

16. 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 SIDE • Thumb & small: RADIAL SIDE

17. ParonychiaAnatomy

18. 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”

19. 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

20. 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

21. Chronic Paronychia • Slightly different disease process with an indolent course marked byexacerbations & 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

22. 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)

23. 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

24. 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

25. 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

26. 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

27. TenosynovitisTreatment • 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

28. TenosynovitisTreatment • 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

29. TenosynovitisTreatment • These incisions: • ensure adequate drainage • heal quickly • Do not interfere with rehab • After removal of catheter and drains begin gentle passive & active ROM

30. 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)

31. Deep Space Infections • 4 deep spaces clinically significant in hand infections: • Subfascial palmar space • Dorsal subaponeurotic space • Thenar space • Midpalmar space

32. 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

33. 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

34. 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

35. 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

36. 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.

37. 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

38. 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

39. Deep Space InfectionsMidpalmar Space Infections • Clinical: • usually due to direct penetrating trauma, rupture of tenosynovitis • loss of palmar concavity, dorsal swelling, tenderness volarly

40. 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.

41. 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

42. Bursal InfectionsTreatment • Closed irrigation using 2 incisions, a catheter & a drain as previously outlined.

43. 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

44. 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)

45. 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

46. 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)

47. 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

48. 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

49. 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.

50. OsteomyelitisDiagnosis • 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