Salvage of Infected INBONE Total Ankle

Replacement

Brent Roster, MD and George Lian, MD

Salvage of Infected INBONE Total Ankle Replacement

Brent Roster, MD

My disclosure is in the Final AOFAS Mobile App.

I have no potential conflicts with this presentation.

Introduction

Reported rates of infection after total ankle replacement (TAR) requiring surgical I&D, component removal/exchange, or revision range from 0-8.6% 1-5,7,8

Traditional two-stage revision procedures can result in significant bone loss, making reconstruction difficult or impossible

The INBONE is a fixed-bearing TAR which utilizes a modular intramedullary tibial stem

Removal of a well-fixed INBONE tibial stem can be difficult and can result in significant morbidity

Biofilms and Periprosthetic Joint Infection

Bacterial biofilm formation on orthopaedic implants confers resistance to both host defense and antimicrobial agents 9

2-stage revision with removal of all components is therefore most commonly successful 5,9

Lombardi et al: 89% success with partial 2-stage revision of infected total hip arthroplasty (well-fixed femoral stems retained) at an average of 4 years 6

Kessler et al reported a 66.7% success rate at an average of 2 years in treatment of infected TAR with retention of one or both components 5

Methods Clinical question:

Can patients with an infected INBONE total ankle replacement AND a well-fixed tibial stem be successfully treated with partial 2-stage revision?

Can well-fixed tibial stem components be retained?

Study Design: Retrospective review of four consecutive patients with an infected INBONE total ankle replacement with at least 2 year follow-up after partial 2-stage revision

Methods

Well-fixed tibial stem components were left in-situ

All patients were treated with surgical I&D, removal of polyethylene, talar, and tibial tray components

Intra-operative cultures were obtained, and antibiotic management was guided by the infectious disease service

Antibiotic beads and antibiotic cement spacers were placed

TAR was re-implanted at an average of 3.75 months s/p explant and spacer placement after being off antibiotics for at least 6 weeks

Clinical exam, radiographs and inflammatory markers checked at most recent follow-up (average 26.5 months status post re-implantation)

Results: Demographics and Risk Factors

Patient Gender Age Initial Diagnosis Risk Factors for Infection

1 M 70 Primary OA DM; debridement and synovectomy for impingement after TAR

2 M 71 Post-traumatic OA None identified

3 M 49 Post-traumatic OA

Hepatitis C; history of open pilon fracture treated with ORIF and subsequent HWR

4 M 59 Post-traumatic OA

Prior foot surgery; debridement and synovectomy for impingement after TAR

OA = osteoarthritis; DM = diabetes mellitus; ORIF = open reduction internal fixation; HWR = hardware removal; TAR = total ankle replacement

Results: Infectious Characteristics

Pt Time to Explant (Months)

Pre-op labs Organism Antibiotic Duration of Abx therapy

Time to re-implantation (Months)

1 41 CRP 277 Alpha-hemolytic Strep

IV daptomycin

6 weeks 2

2 43 WBC 9.2, ESR 108

Propionibacterium PO rifampin & minocycline

1 year 4

3 39 CRP 0.8, ESR 31, WBC 8.1

Pseudomonas aeroginosa; GBS

cefepime 6 weeks 4

4 33 ESR 37, CRP 56.9, WBC 8.6

MSSA nafcillin 6 weeks 5

Avg = 39 Avg = 3.75

CRP = C reactive protein, mg/L, normal 0-9; WBC = white blood cell count, K/uL, normal = 4-11; ESR = erythrocyte sedimentation rate, mm/hr, normal 0-20; GBS = group B Streptococcus; MSSA = methicillin sensitive Staphylococcus aureus

Results: Most Recent Follow-up Pt F/u after re-

implantation (months)

ROM Narcotics? Clinical signs of infection at ankle?

Labs

1 34 35 no no WBC 5.8 ESR 17 CRP 0.5

2 24 22 no no WBC 6.0 ESR 31 CRP 5.5

3 24 25 no no WBC 7.3 ESR16 CRP 2.9

4 24 30 no no *** WBC 9.2 ESR 32 CRP 25.3

Avg = 26.5

*** At most recent f/u, Patient #4 had a pressure wound over the contralateral ankle and infected abdominal hernia mesh after bowel rupture during colonoscopy with resultant colostomy; operative ankle was benign with no signs of infection

Pre-op to Re-Implantation

Pre-op After I&D, poly and talar component removal and placement of antibiotic cement spacer

24 months after re-implantation

Discussion/Conclusion

4/4 patients treated with this approach had functional revision TARs at an average of 26.5 months follow-up

4/4 had no clinical signs of infection of their TAR

1/4 had elevated inflammatory markers at most recent follow-up, with an explanation other than their TAR

Conclusion: In this small series of 4 patients, all were successfully treated with partial 2-stage revision for infection with retention of the well-fixed INBONE tibial components with at least 2 years follow-up.

References

1. Adams SB, Demetracopoulos CA, Queen RA, Easley MF, DeOrio JK, Nunley JA. Early to mid-term results of fixed-bearing total ankle arthroplasty with a modular intramedullary tibial component. J Bone Jonit Surg Am. 2014;96:1983-9.

2. Daniels TR, Younger ASE, Penner M, Wing K, Dryden PJ, Wong H, Glazebrook M. Intermediate-term results of total ankle replacement and ankle arthrodesis. J Bone Joint Surg Am. 2014;96:135-42.

3. Gougoulias N, Khanna A, Maffulli N. How successful are current ankle replacements? Clin Orthop Relat Res. 2010;469:199-208.

4. Kessler B, Sendi P, Graber P, Knupp M, Zwickey L, Hintermann B, Zimmerli W. Risk factors for periprosthetic ankle joint infection: a case control study. J Bone Joint Surg Am. 2012;94:1871-6.

5. Kessler B, Knupp M, Graber P, Zwicky L, Hintermann B, Zimmerli W, Sendi P. The treatment and outcome of periprosthetic infection of the ankle. J Bone Joint Surg Br. 2014;96-B:772-7.

6. Lombardi AV, Berend KR, Adams JB. Partial two-stage exchange of the infected total hip replacement using disposable spacer moulds. J Bone Joint Surg Br. 2014;96-B(11 Supple A):66-9.

7. Myerson MS, Shariff R, Zonno AJ. The management of infection following total ankle replacement: demographics and treatment. Foot Ankle Int. 2014;35(9):855-862.

8. Sadoghi P, Roush G, Kastner N, Leithner A, Sommitsch C, Goswami T. Failure modes for total ankle arthroplasty: a statistical analysis of the Norwegian Arthroplasty Register. Arch Orthop Trauma Surg. 2014;134:1361-1368.

9. Zimmerli W, Moser C. Pathogenesis and treatment concepts of orthopaedic biofilm infections. FEMS Immunol Med Microbiol. 2012;65:158-168.