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SyCap: A novel implant to address
the treatment gap for middle-aged
patients with focal cartilage defects
Maria Pastrama, TU/e
October 9th, 2019
Focal knee cartilage defects (FCD)
0
50,000
100,000
150,000
Total 40y - 60y
FCD incidence per year (US & Europe)Femur
Tibia
FCDs: Treatment gap for middle-aged patients
?
Regenerative
therapy
Total knee
replacement
40-60 years > 60 years< 40 years
Resurfacing
metal implants
Resurfacing metal implants: Drawbacks
No MRI monitoring Damage to opposing tissue
FCDs: Treatment gap for middle-aged patients
?
Regenerative
therapy
Total knee
replacement
40-60 years > 60 years< 40 years
SyCap: Objective
Develop a non-resorbable implant for the treatment of cartilage
defects in middle aged patients
SyCap: Design
SyCap: Mechanical properties
CartilageSyCap top
layer *
Trabecular
bone
SyCap bottom
layer *
(Apparent)
Modulus [MPa]2–25 10–37 390–650 450–598
T.A. Burgers et al. J Biomech. 41: 1077–1085, 2008; D. Shepherd and B. B. Seedhom, Ann. Rheum. Dis., 58(1): 27–34, 1999; D. Shepherd, Rheumatology,
38(2): 124–132, 2002.
* in water at 37º C
Spray coating method
SyCap: Benefits & unique selling points
◆ Biomechanics closely mimics cartilage biomechanics
◆ Allows for postoperative MRI (no substantial metal)
◆ Off-the-shelf, minorly invasive procedure
SyCap: Animal studies
2017
In vivo 1A
2018
In vivo 1B
2019
In vivo 2
Evaluation methods
MRI
X-Ray
Micro-CT
Histology
SyCap: Animal studies
2017
In vivo 1A
2018
In vivo 1B
2019
In vivo 2
Animal Study 1A
◆ 20 skeletally mature Dutch milk goats (3.2±0.5 years, 82.6±9.4 kg)
◆ BCP-coated/uncoated PCU implants vs. metal implants inserted
bilaterally into medial femoral condyle
◆ 12 week follow-up
◆ Primary outcome measure: Implant osseointegration
bone-implant contact (BIC) [%] on histology
Preclinical in vivo data: Excellent osseointegration &
cartilage preservation
Patent Application
Conclusions Animal Study 1A
◆ Coating is effective in stimulating osseointegration for solid PCU
implants
◆ Surgical technique can be further improved
– Pre-drilling
– Press-fit
◆ Modify implant shape in order to improve translation from goat implant
design to human implant design
Implant shape: Finite Element Analysis
Horizontal strain (εxx)
Heuijerjans 2018
Conclusions Animal Study 1A: Design update
Shape
Press-fit
Surgical procedure
SyCap: Animal studies
2018
In vivo 1B
2017
In vivo 1A
2019
In vivo 2
Animal Study 1B: Osseointegration
◆ 16 skeletally mature Dutch milk goats (2-3 years, 60-80 kg)
◆ Implants inserted bilaterally into medial femoral condyle
◆ 12 week follow-up
◆ Primary outcome measure: Implant osseointegration
bone-implant contact (BIC) [%] on histology
Animal Study 1B: Osseointegration
SyCap: Animal studies
2019
In vivo 2
2017
In vivo 1A
2018
In vivo 1B
Animal Study 2: Long term adjacent & opposing cartilage
assessment
◆ 32 skeletally mature Dutch milk goats (2-3 years, 60-80 kg)
– PCU implant 1 (Bionate)
– PCU implant 2 (Bionate composite)
– Sham
– Metal implant
◆ Implants inserted bilaterally into medial femoral condyle
◆ 26 & 52 week follow-up (n=8 knees per group)
◆ Primary outcome measure: histological scoring of opposing cartilage
OOCHAS score
Animal Study 2: Preliminary results
Metal implant SyCap
Optical profiling Ultrasound imaging
Animal Study 2: Roughness measurements
Outlook: Human implant design
Human
implant
design
Human implant design: Full knee FE analysis
van de Wetering 2019
Effect of implant curvature and placement depth
van de Wetering 2019
Perfect curvature
Flat implant
’’Good’’ placement
Flat implant
’’Bad’’ placement
Thank you!
SyCap project
René van Donkelaar
Pieter Emans
Frank Everaerts
Jessica Gerards
Pieter van Hugten
Ralph Jeuken
Filip Maes
Henk Oevering
Alex Roth
Jens Thies