Perils and Pearls in

1
Perils and Pearls in the Management of the
Infected Total knee
Mark A. Snyder, M.D.
2
Clinical Experience Between 1990 to 1999

• 56 infected TKR in 56 patients
• 54 with positive bacteriologic diagnosis by the
  time of revision
• 2 with subsequent bacteriologic diagnosis at time
  of septic failure
• 34 s. aureus, 15 s. epidermidis, 3 beta
  hemolytic streptococcus, 2 pseudomonas, 1
  enterococcus, 1 MRSA
• 5 immediate exchange revision with antibiotic
  inclusion in the cement
• 29 two-stage revision with cement spacer
• 22 two-stage revision with articulating spacer

3
Peril The Failure to Recognize Patients at
Increased Risk for Sepsis

• Immunologically impaired host (RA,
  chemotherapy)
• Previous open knee surgery
• Previous joint infection and osteomyelitis
• Skin ulcerations
• Diabetes
• Thomas, CORR, 1983
• Poss, CORR, 1984
• Jerry, CORR, 1988
• England, CORR, 1990
• Wilson, JBJS, 1990
• Windsor, JAAOS, 1994

66 WM Diabetes Prior HTO Sepsis lt1 y After TKR
4
Pearl Identify and Reduce Sepsis Risks

• Meticulous History and Physical
• Wait until skin ulcers healed
• Preop aspiration if history of infection
• Frozen section at time of surgery with less than
  5 WBC per hpf from five sites (Feldman, JBJS,
  1995)
• Consider antibiotic inclusion in cement 1.0 gm
  Vancomycin and 1.2 gm Tobramycin per pack of
  Palacos
• Meticulous closure
• Be ready to flap for gaps
• lt0.5 sepsis in gt200 high risk TKR patients since
  1990

5
Peril Failing to Diagnose the Infected TKR on a
Timely Basis

• If sepsis is diagnosed more than 4 weeks after
  the index procedure, open debridement and
  irrigation are probably ineffective.
• Procrastination and the use of oral antibiotics
  greatly complicate the eventual salvage of the
  infected TKR.
• The absence of joint aspiration bacteriologic
  data before revision compromises antibiotic
  management.
• Hartman, CORR, 1991
• Duff, CORR, 1996
• Barrack, CORR, 1997

6
Pearl Have a High Index of Suspicion

• Pain with activity and at rest
• Persistent swelling
• Persistent drainage
• Prolonged elevation of ESR, CRP
• Early, progressive lucencies
• Loose hinged arthroplasty (20 times increased
  incidence in Poss, CORR, 1984)

7
Pearl Obtain Preop Joint Aspiration Data

• Repeat over several weeks if previously on
  antibiotics
• Avoid skin contamination during aspiration
• Avoid suppression of bacterial growth by using
  local anesthetics or saline wash with
  preservatives
• Realize that preop aspiration provides
• 75-100 sensitivity
• 96-100 specificity
• 90-100 accuracy (Duff, 96 and Barrack, 97)

8
Peril Misapplication of Treatment Options

• Open debridement and irrigation if sepsis
  diagnosed greater than four weeks after index
  procedure
• Revision without antibiotic inclusion in the
  cement
• Immediate exchange arthroplasty without favorable
  organism and antibiotic sensitivity profile
• Fusion in the elderly patient with adequate bone
  stock and intact extensor mechanism
• Resection in the ambulatory patient with single
  joint disease
• Amputation for reasons other than relentless,
  life/limb threatening infection

56 Diabetic Poly failure Rest pain for 2
months Preop aspiration
Schoifet, JBJS, 1990
Goksan, JBJS(B), 1992 Hanssen,
CORR, 1994 Knutson, JBJS, 1985
Falahee, JBJS, 1987
9
Pearl Two-stage Revision Techniques Offer the
Greatest Chance to Control Infection and Preserve
Function

• Rand, JBJS, 1983
• Insall, JBJS, 1983
• Borden, J Arthroplasty, 1987
• Rosenberg, CORR, 1988
• Wilde, CORR, 1988
• Hirakawa, J Arthroplasty, 1998
• Tenny, J Arthroplasty, 1990
• Wilson, JBJS, 1990
• Windsor, JBJS, 1990
• Hanssen, CORR, 1994
• Masri, Semin Arthroplasty, 1994
• Whiteside, CORR, 1994
• Hoffman, CORR, 1995
• Goldman, CORR, 1996

90
10
Peril Inadequate Pre-op Planning for the
Two-stage Revision

• Sub optimal patient health status
• Previous incisions not considered
• Status of extensor mechanism unknown
• Lack of bacteriologic diagnosis
• Unanticipated osteolysis (esp. posterior femoral
  condyles)
• Implant extraction and cement removal challenges
• Incomplete array of surgical exposure options
• Unanticipated wound closure problems

11
Pearl Careful Pre-op Planning

• Complete screening of patient and knee risk
  features
• Antibiotic profiles defined
• Plastic surgery consult for closure and coverage
  challenges
• Inform patient that muscle flap procedure may be
  added on
• High speed power and ultrasonic tools available
  in addition to revision instrument tray
• Spacer versus articulating option anticipated
• Modular revision system sophisticated enough for
  osseous and soft tissue challenges (i.e.,
  ?adequate constraint)
• Antibiotic cement combinations address fatigue
  strength and elution concerns

Septic nonunion with failed IF
12
Peril Failure to Confirm Infection by the Time
of Revision

• Inadequate antibiotic coverage
• Increased risk of septic recurrence

Immediate exchange Preop aspiration neg Frozen
sections neg MRSA reinfection
13
Pearl Remember to Utilize intraoperative Frozen
Sections

• If all preop aspirations are negative, but
  clinical signs and radiographs suggest infection
  be sure to obtain frozen sections.
• If at least five distinct microscopic fields
  yield more than 5 WBC/hpf, consider the
  arthroplasty infected. (Feldman, JBJS, 1995)
• If the frozen sections are positive, proceed with
  a spacer or articulating spacer with at least 2.4
  gm of Tobramycin and 1.0 gm of Vancomycin per
  pack of Palacos.
• If the frozen sections are negative in the face
  of clinical/radiograph suspicions, include
  antibiotics in the cement.

Use of antibiotic-impregnated bone cement for
prosthesis fixation at revision surgery was the
only variable that correlated with the cure rate
of deep infection. Hanssen AD, Rand JA, Osman
DR, CORR, 1994.
14
Peril The Challenges of Surgical Exposure Not
Anticipated

• Loss of extensor mechanism
• Periprosthetic fractures
• Excessive operative length
• Inadequate debridement

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Pearl Know How to Gain Exposure

• Midline incision (if possible)
• Radical synovectomy
• Quad snip for extension tightness (Garvin, CORR,
  1995)
• Lateral retinacular release if unable to evert or
  displace the patella
• Modified patellar turndown (Barrack, AAOS ICL,
  1999)
• A 4 cm, or more, proximal tibial osteotomy
  (Whiteside, CORR, 1995)

16
Peril Stiffness After the Extraction and
Debridement Procedure

• Particularly an issue if the second stage is
  delayed several months.
• Can increase exposure challenges and hazards at
  the time of definitive revision
• May compromise range of motion
• 29 spacer revisions ROM -7.5 to 80
• 22 articulating spacer ROM -5.0 to 104

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Pearl Consider the Articulating Spacer Technique

• Use alignment guides and cutting jigs to correct
  deformities
• Reuse the extracted femoral component if there is
  minimal surface damage
• Use at least 2.4 gm Tobramycin and 1.0 gm
  Vancomycin per Palacos batch
• Apply the antibiotic-impregnated cement in a
  dough phase onto wet bone surfaces

Beta strep septic TKR articulating spacer 1
month postop
18
Peril Bone Loss Due to Spacer Blocks

• Increases with displacement of the spacer
• Increases in the presence of angular deformity
  and ligamentous imbalance
• Degree of bone loss can exceed 1 cm (Calton,
  CORR, 1997)

19
Pearl Spacers Useful with Attention to Certain
Details

• Cut the bone and shape the spacer for maximum
  contact and best alignment
• Determine the height of the spacer during
  extension tibiofemoral distraction
• Shape a 1 to 2 cm IM stem on the tibial surface
  to prevent displacement
• Optimize size for both contact and capsular
  closure
• Consider a patellar shield to reduce
  peripatellar adhesions

20
Peril High Rates of Reinfection and Poor
Functional Outcomes

• Procrastination in the diagnosis of infection
• Absence of bacteriologic information at time of
  revision
• Failure to diagnosis persistent infection at the
  time of staged revision

21
Peril High Rates of Reinfection and Poor
Functional Outcomes

• Inadequate debridement of abscesses and
  osteomyelitis
• Inadequate duration of parenteral antibiotics
  after excision
• Omission of antibiotic impregnated cement at
  final revision
• Failure to obtain durable soft tissue closure

22
Peril High Rates of Reinfection and Poor
Functional Outcomes

• Loss of extensor mechanism
• Poor range of motion (less than 20 to 90 degrees)
• Bone loss beyond that managed with implant
  modularity or custom implants
• Early revision implant loosening

23
Pearl A Systematic Approach to Septic Revision
Based on the Literature and a Large Clinical
Experience

• Suspect infection if PAIN and SWELLING
• Obtain joint aspiration data
• Open debridement if sepsis diagnosed less than 4
  weeks postop
• Two-stage reimplantation is first choice
• Thorough debridement and aggressive soft tissue
  coverage including gastroc flaps

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Pearl Systematic approach

• Articulating spacer with Vancomycin and
  Tobramycin
• Six weeks of parenteral antibiotics
• Reimplant if aspirations and frozen sections
  negative
• Apply reliable revision principles exposure,
  modularity, stems to bypass defects, antibiotic
  impregnated cement

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56 Infected TKR Experience

• 5 immediate exchange revisions
• Ave FU 4.8 y
• Reinfection 1 (20)
• Rest HSS 87.5
• No pending revisions
• Organisms 3 beta
• hemolytic strep,
• 1 s. epi, 1 MRSA

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56 Infected TKR Experience

• 29 two-stage revisions with cement spacer
• Ave FU 5.9 y (25)
• Deceased 2
• Lost to FU 2
• Reinfection 3 (12)
• Rest HSS 79.4
• Poor ROM 7 (28)
• Organisms 18 s. aureus,
• 5 s. epi, 1 enterococcus,
• 1 pseudomonas
• Revised 6(24), 3 for
• infection, 3 for extensor
• mechanism failure

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56 Infected TKR Experience

• 22 two-stage with articulating spacer
• Ave FU 2.8y (22)
• Reinfection 1 (4.5)
• Rest HSS 84.5
• Poor ROM 2 (9.1)
• Infection free and with good to excellent
  results
• 18 (81.8)
• Organisms 14 s. aureus,
• 8 s. epi
• Revised 2 (9.1), 1 for infection and 1 for
  patellar loosening and osteonecrosis