1. Ankle Arthroplasty: Can the Ankle Joint be Replaced ?
Arash Aminian MD

2. Anatomy Biomechanics History Current Designs Indications Results Cases
Overview
Anatomy
Biomechanics
History
Current Designs
Indications
Results
Cases

3. Anatomy Talar Bony Anatomy 60% cartilage Blood supply Deltoid
Artery of the sinus tarsi
Artery of the tarsal canal

4. Anatomy
Distal Tibial Anatomy

5. Anatomy: Stability Ankle ligaments Articular geometry
Stormont et al AJSM : 295.
Ankle ligament sectioning study: Articular surface 30%
rotational stability

6. Lateral Ankle Ligaments
Anatomy: Ligaments
Lateral Ankle Ligaments

7. Anatomy: Ligaments Deltoid (abduction/ER) Syndesmosis
Anterior and Posterior Tibia-Fibula
Interosseous
Transverse T-F

8. Anatomy: Motion Multi-axial Motion DF EV Foot, IR Tibia PF
IN Foot, ER Tibia
Normal Motion
DF 13-33 PF
Walking DF/PF 10/10-15 degrees

9. Biomechanics: Bone Support
Subchondral bone of distal tibia modulous of elasticity
MPa
Removal of:
Subchondral bone lower compressive resistance by 30-50%
1 cm of bone by 70-90%

10. Biomechanics Vertical load 5.2 x BW during normal gait GR forces 3D
Compressive
Shear
Torsional
Micromotion (0.15 mm) prevents ingrowth
CORR :

11. History: Questions Restore Anatomy Which Surfaces to replace Fixation
Poly size (4-6mm Hip, 6-8mm Knee, Ankle?)

12. History: Classification
Fixation: Cemented, Uncemented
Number of components: 2/3
Constraint: Constrained/Semi/Non
Congruity/Conformity
Component shape: Anatomic/Non-anatomic
Bearing: Fixed/Mobile

13. History: 1970s First Generation
Poorly designed instruments: mal-position
Soft tissue balancing not addressed
Bone cement for fixation
Excessive bone removal
Non-anatomically shaped implants
Soft tissue envelope

14. History: 30 year Follow-up

15. Ankle Arthritis:
Comparison of Health-Related Quality of Life Between
Patients with End-Stage Ankle and Hip Arthrosis.
Glazebrook et al. J Bone Joint Surg Am.2008; 90:
SF 36 scores cohort 136 ankle arthrosis/130 hip
arthrosis
Ankle arthrosis: worse mental component
summary, role-physical score, general health
score

16. Why Total Ankles: Ankle Fusion Nonunion rate 5-10%
Gait: Difficulty with climbing stairs,
walking on uneven grounds (Decreases DF 50%/ PF 70%)
Adjacent joint arthritis:
23 year F/U 95% hindfoot arthrosis (JBJS B 85:994)
12-44 year F/U 91% subtalar; 57% TN arthrosis (JBJS A Caster et al 83: 219)

17. History: Second Generation
Constraint:
Resistance of the implant to degrees of freedom (shear stresses). Decreasing constraint minimizes shear stress forces at the bone-implant interface
Congruity/Conformity:
Radii of curvatures of the implant and poly-wear

18. Current Designs Agility (1984) Hintegra TNK Inbone (2005) STAR (2009)
Salto-Tolaris (1997/2006)
Buechel-Pappas

19. Ideal Design Small bone resection
Anatomic (physiologic motion/balance ligaments)
Unconstrained
Porous surface (ingrowth within 3D spaces) with HA
(early fixation)
Large prosthesis (prevent subsidence)
Motion DF/PF 10/20 degrees
Poly 8 mm (increase durability)
Poly conforming (decrease contact stresses: prevent
loosening)

20. Indications and Considerations:
Age
Primary/Secondary Arthritis
Deformity
Good bone stock
Normal neuro-vascular exam
Motion
Ankle Stability
Low physical demand

21. Relative Contra-Indications:
AVN
Severe osteoperosis/penia
IDDM
Demanding work/sport activities
Weight?
Previous Infection?

22. Absolute Contra-Indications
Deformity greater than 10 degrees
Ligamentous Instability (lateral/medial)
Poor soft-tissue envelope
Neurovascular compromise
Acute infection
Joint hypermobility

23. Salto-Tolaris TAA FDA Approval 2008 2 component design Instrumentation
Resection level
Uncemented
Anatomic

24. Results: Literature Review
Intermediate and Long-Term Outcomes of Total Ankle Arthroplasty and Ankle Arthrodesis. A systematic review of the Literature.
Haddad et al. J Bone Joint Surg Am.2007; 89:
TAA: 5 year survival 78%
10 year survival 77%
Revision rate of 7%: Loosening or subsidence

25. Results: How successful are TAA
Residual pain is common (27-60%)
Superficial wound complications (0-14.7%)
Deep wound complications (0-4.6%)
Overall failure rate 10% at 5 years
Gougoulias et al. CORR 2010 Jan:468(1):

26. Results: Survivorship 7-11 years for Salto TAA
85 patients (87 TAA): mean follow-up 8.9 years (6.8-11
years)
Survival rate 65% with any reoperation, 85% with
revision as an end point
Causes of reoperation:
Bone cysts (11)
Fracture of the polyethylene (5)
Pain (3)
Bonnon M et al. CORR 2010 Jul 1

27. Complications: Evidence Based Classification of Complications in Total Ankle Arthroplasty Glazebrook et al Foot and Ankle Int 2009 Oct30(10):
Deep infection
Aseptic loosening
Implant failure
Subsidence
Fractures (intra-op/post-operative)
Wound healing problems

28. TAA vs Ankle Fusion ?
Preference-based Quality of Life of End-stage Ankle arthritis with Arthroplasty or Arthrodesis
Slobogean et al. Foot and Ankle Int 2010 July 31(7):
Prospective study 107 patients with TAA /Arthrodesis:
At one year follow-up SF-36 score TAA (0.73),
Arthrodesis (0.73)

29. Outcome Measures 82 patients, average follow-up 60 months
JBJS Am Jan 4;94(1): Intermediate to long-term outcomes of the STAR Total Ankle Replacement: the patient perspective.
82 patients, average follow-up 60 months
The most compelling finding of the present study involved the marked improvement in terms of the self-reported measures of impairments, quality of life, pain, and function.

30. Acta Orthop Dec;82(6):655-9.
10-year survival of total ankle arthroplasties: a report on 780 cases from the Swedish Ankle Register.
Of the 780 prostheses implanted since 1993, 168 (22%) had been revised by June 15, The overall survival rate fell from 0.81 (95% CI: ) at 5 years to 0.69 (95% CI: ) at 10 years. .
Outcome Measures

31. Outcome Measures Foot Ankle Int. 2011 Aug;32(8):740-5.
Revision rates after total ankle arthroplasty in sample-based clinical studies and national registries.
These were STAR Ankle, Büchel-Pappas, Hintegra, Mobility, Agility, and Ramses Total Ankle Arthroplasty. The revision rate was used as the main outcome parameter.
Irrespective of the implant, the average revision rate to be expected according to the registry data available is 21.8% after 5 years, and 43.5% after 10 years.

32. 74 year old female with long standing ankle pain
Salto prosthesis
74 year old female with long standing ankle pain

33. Case 1 Year Follow-Up

34. Case 3 Year Follow-Up

35. Case: 3 Year Follow-up

36. Case: 3 Year Follow-up

37. Inbone prosthesis

38. Inbone prosthesis

39. STAR

40. STAR

41. Don’t Underestimate a Good ankle Fusion