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