1. Management of Infection and Periprosthetic Fracture in TKR
蔡旻虔, 徐郭堯
膝關節重建與運動醫學科
長庚林口醫學中心

2. Management of Infection After Knee Arthroplasty

3. Infection after TKR: 0.5% ~ 2%
無論診斷與治療,都是一項很大的挑戰
TKA術後有任何的pain或不適,都要先想是不是有infection的問題

4. infection
host
bacteria
path, wound

5. Pathogens present to implant
Surgical contamination
Hematogenous spread
Recurrent infection
Direct inoculation or contiguous spread
Schmalzried,et al. Clin Orthop.1992

6. Pathogen Most popular pathogen of biomaterial – associated infection
- Staphylococcus species
aerobic Gram-negative bacteria
- 10% ~ 20%
anaerobic bacteria
- 10%

7. Pathogen Early-onset infection (< 3 months) - virulent pathogen
- S aureus, G(-) bacilli
Delay-onset infection (3 ~ 24 months)
- less virulent
- coagulase-nagative staphylocicci
Late-onset infection (> 24 months)
- S aureus, CoNS, E Coli …….

8. Biofilm
Microorganisms encapsulated within a self-developed polymeric matrix and adherent to a biomaterial surface
Pathogen more resists to
- antibiotics
- phagocyte
Debridement

9. Host risk factor for periprosthetic infectionDM
Obesity (BMI > 30)
Old age (> 80 y/o)
ASA > 2
Smoking
Hepatic insufficiency
Renal insufficiency
…...

11. Classification of deep periprosthetic infection
Type
Presentation
Definition I
Positive Intra-op
Culture
> 2 positive intra-op culture II
Acute Post-op infection
Acute infection within
4 weeks after the operation
III
Acute hematogeneous infection
Acute onset of infection at a previously well-functioning joint replacement IV
Late chronic infection
Chronic infection,
Infection presents > 1 month

12. Diagnosis Symptom and sign - fever, chillness
- sever joint pain, especially rest pain
- local heat and swelling effusion
- pus discharge, discharge sinus

13. Diagnosis Radiographic study - nonspecific change
implant loose, osteolysis, …
- to rule out other conditions

14. Diagnosis Radionuclide image - Bone scan - Gallium scan - WBC scan
- PET scan

15. Diagnosis Hematologic test - WBC - ESR - CRP Joint aspiration
Frozen section
- < 5 PMN in each HPF

16. Treatment Treatment options - antibiotics use - debridement
- resection arthroplasty
- exchange arthroplasty
- stage revision arthroplasty

17. Treatment Considerations - type and duration of symptoms
- detail postoperative course
- local condition
- host condition
- implant condition

18. Debridement
- Early infection (type II) or infection with
symptoms< 1 month (type III)
- Stable prosthesis
- No discharging sinus

19. Two-stage revision For delay or late onset infection Popular use
High successful rate

20. Two-stage revision Removal of implants and debridement
and joint stabilized with anti-loaded
cement spacer
IV anti use 4 ~ 6 weeks
f/u CRP and clinical S/S
Reimplamtation implants

21. Optimal timing for reimplantation
6 ~ 12 weeks after 1st stage op
Sequential CRP f/u
Follow up local condition
Delay aspiration 2~4 weeks after DC anti
Intra-op frozen section

22. Prevention Host - Identified the risk factor
- Careful screen occult or minor infections
prior to TKR
Operation field
Prophylaxis antibiotics
- cefazlion 1g IV less than 80 kg, 2g IV
more than 80 kg
- repeat dose in 2 ~ 5 hr interval

23. TKA periprosthetic fracture

24. Fracture in TKA
A very challenging problem to orphopaedic doctors

25. What’s the problem we face
Old age patient
High Anesthesia and OP risk
Poor bone stalk
Difficult to fixation
Implant stability
Knee function

28. Incidence of femoral fracture after TKA
After Primary TKR %
Merkel KD, Johnson EW. J Bone Joint Surg 1986;68:29–43
After revision TKR
1.6%-38%
Kang-Il Kim, MD; Kenneth A. Egol, MD. CORR 2006; 446: 167–175

29. Femoral supracondylar fracture after TKA
Severe osteoporosis
Usually D/3 of femur
Within 15cm of joint line
Often cause by low energy trauma

30. Risk factors Patient factors Local factors
Rheumatoid arthritis Osteolysis
Osteoporosis Anterior femoral notching
Steroid use Stress risers
Neurologic disorders Loosening
Smoking Stiffness knee
Immunosuppression
Female sex
Frequent falls

31. Classification
Lewis & Rorabeck, 1998

32. Rorabeck Classification Type II

33. Rorabeck Classification Type III

34. Treatment Goal Stable fracture site Restore alignment
Preserve bone stock
Early range of motion
Restore knee function

35. Pre-OP planning Type of fracture Degree of displacement Type of TKA
Presence of infection or loosening of the prosthesis
patient factors
pre-fracture morbidity, mobility and bone quality.

36. Treatment methods Conservative treatment Operative management
Open reduction and internal fixation
Revision TKR
Custom made prosthesis

37. Plate fixation
Fixed angle Plate
Conventional DCP

40. Plate fixation Advantage Disadvantage
good visualization of fracture site
Less technique demand
Disadvantage
Another approach
Soft tissue compromise
Difficult reduction
Unable to change linear
Plate failure in poor bone stalk

41. Locking plate system

42. Locking plate system Advantage Disadvantage Uni-cortex purchase
Prevent plate-bone compression
Anatomic contour
Disadvantage
Limited screw direction
Unable to bending

43. Is single plate enough??

44. Is single plate enough??

45. After 3 months…

46. Double plate fixation

47. For plating fixation Single conventional plating is not enough
Double plating or combined with locking plate is more stable

48. Retrograde Nail

51. Retrograde Nail Advantage Disadvantage Less invasive (same incision)
Easy apply and reduction
Possible change linear
Disadvantage
Limited by prosthesis design
CR vs PS type
Distal fixation

52. Retrograde nail + Plating
Single approach
Easy apply + reduction
Very stable fixation
Axial stability
Rotation stability
May change liner if necessary

55. Revision TKR Indication Implant choice Severe comminuted fracture
Fracture associated implant loosening
Implant choice
Log stem prosthesis
Allograft-prosthesis complex (APC)
Tumor prosthesis or custom made

58. Key- points Pre-Op planning Maintain alignment Stable fixation
Retrograde nail combined plating
Chang insert if necessary
Double plating /locking plate
Adequate bone grafting

59. Thanks for attention!!