This document discusses partial resurfacing implants, specifically the BioPoly implant. It provides details on the BioPoly material which is a combination of UHMWPE and hyaluronic acid. It then summarizes a registry study of 35 patients who received the BioPoly implant with results showing significant improvement in clinical outcomes and one revision. The conclusion is that partial resurfacing implants have limited primary indications but can be useful for failed cartilage repair procedures.

1. Prof. Vladimir Bobić
MD FRCSEd, Consultant Orthopaedic Knee Surgeon
Chester Knee Clinic at Nuffield Health, The Grosvenor Hospital Chester, United Kingdom
www.kneeclinic.info office@kneeclinic.info @ChesterKnee
Partial Resurfacing Implants
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39th World Congress, Montréal, Canada 10-13 October 2018

2. Relevant Disclosures
Royalties received from Schwartz Biomedical
Paid Consultant for intellectual property
(BioPoly implant and instrument design),
Schwartz Biomedical
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3. Articular Cartilage Repair: Surgical Options
ACI/MACI
BioPoly: Filling the Void?
OATSMicrofracture
Allografts UKR & TKR
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4. Partial Resurfacing Implants
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HemiCAP Knee Implants
No personal surgical experience with Episealer or HemiCAP implants,
therefore this presentation will be limited to BioPoly implants.

5. BioPoly Femoral Resurfacing Implant
Articular Component: Patented Combination UHMWPE + HA
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6. • BioPoly® Material
– “Microcomposite” (UHMWPE and Hyaluronic Acid)
– Hydrophilic (water attracting) polymer
• Hyaluronic Acid within BioPoly®
– Attracts synovial fluid for lubrication
– Allows for articulation with cartilage
• No damage to opposing cartilage surfaces
• No damage to implant surface
• Resurfacing Applications
BioPoly® Technology Overview
Hyaluronic Acid
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7. BioPoly - Deformed shape at 1000N
(note larger area of tibial cartilage engaged in load sharing)
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8. Results in lower opposing cartilage contact pressure
(2.5x body weight load)
BioPoly
Tibial Cartilage
Contact Pressure
Peak = 3.46 MPa
Active Contact Zone
Loaded Area ~ 471
mm2
Metal Implant
Tibial Cartilage
Contact Pressure
Peak = 7.24 MPa
Active Contact Zone
Loaded Area ~ 314 mm2
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9. Current BioPoly® RS Partial Resurfacing
3 Families of Products
BioPoly® RS KNEE
CE Marked
BioPoly® RS PATELLA
CE Marked
BioPoly® RS SHOULDER
CE Marked
Patella
Humeral
head
Distal Femur
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+ BioPoly® RS Femoral Trochlea and Talar Dome in the pipeline

10. ®Confidential
BioPoly RS Knee and Patella System
• CE Marked
• Suitable for cartilage defects in the distal
femur and patella up to 3.1 cm2
• Femoral Condyle and Trochlear Facet
Implants
– Ti64 grit blasted stems. Press fit or cemented
• Patella implants
– All BioPoly construction for cementation
• Simple surgical instrument set and
technique
• Existing reimbursement codes
Femoral Condyles and
Trochlear Facets
Patella
15mm 20mm 15x24mm
15mm/0 15mm/1 20mm/0 20mm/1
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11. Indications : Lesion Characteristics
• Medial or Lateral femoral condyle, NOT tibial condyles
• Focal 2cm2 or (2.4 x 1.5) cm2 ≤3.1cm2 (Entire lesion visualized in static knee through static arthroscope)
• ICRS grade 2, 3, or 4
• Contained ICRS 0/1
• Depth from articular surface < 4mm
• Good subchondral bone (MRI)
X11

12. Contradictions
Lesion characteristics:
• Uncontained
• Very large
• >1 implant required
• Kissing lesion
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13. Contradictions
Other joint pathology
• Malalignment
• Laxity
• Major meniscal deficiency
• Subchondral sclerosis
• Advanced degenerative changes
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14. 14
BioPoly RS Knee Surgical Technique

15. Race-track BioPoly
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16. 16

17. Cemented all BioPoly Implant
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18. BioPoly® RS Partial Resurfacing Knee Implantations
6 yrs
700+ cases
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19. Study Investigators and Collaborators:
Prof Vladimir Bobic - Chester Knee Clinic, Chester, UK
Prof Mike McNicholas – Aintree, Liverpool, UK
Mr Dinesh Nathwani - Imperial College, London, UK
Prof Alister Hart - RNOH Stanmore, London, UK
Mr Jonathan Miles - RNOH Stanmore, London, UK
Matt Hill - Schwartz Biomedical, USA
Herb Schwartz - Schwartz Biomedical, USA
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20. Registry Study Design
• Study Type: Post-market registry
• 35 patients & 4 UK Centres
• Control: Historical microfracture outcomes
• Outcome measures: KOOS, VAS, Tegner, SF-36
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Major Inclusion and Exclusion Criteria
Inclusion Criteria Exclusion Criteria
• Age 21 years and older • Body Mass Index (BMI) ≥ 30
• Symptomatic lesions classified as ICRS grade 2, 3, or 4 • Generalized degenerative or autoimmune arthritis
• Lesion size ≤ 3.1cm2 circumscribed by normal or nearly normal
(ICRS grade 0 or 1) cartilage with an overall depth ≤ 4mm
from the articulating surface
• Uncorrected chronic malalignment of the knee*
• Uncorrected ligamentous instability*
• Uncorrected mechanically symptomatic meniscal tear or
total meniscectomy*
• Sufficient subchondral bone quality to support implant • Kissing lesion on tibia
• More than one implant required to accommodate lesion
• Use with opposing articulating tibial components
*Can be corrected during surgery

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22. Registry Study: Preliminary Report
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23. 23

24. 24
Registry Study Results

25. Registry Study Results
• Interim results after 2
years indicate:
– Significant improvement in
all clinical outcomes
– One revision (2.9%) due to
subchondral bone disorder
– No differences between
younger and older patients
• Mean Defect size = 2.7cm2
• Over half of patient population (54.3%) failed previous
cartilage repair procedures
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26. 26

27. Registry Study Results
• BioPoly compared to historical microfracture outcomes
– BioPoly patients on average 7 – 9 years older
• Significantly superior KOOS QoL and Sport after 2 years
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28. Patient Adverse Events
• 1 Wound infection reported after 1/12
– Resolved quickly with medication
• 1 Patient began experiencing pain at 3/12
– Arthroscopy revealed implant intact, and loose
cartilage body as source of pain
– Removal of loose cartilage body resolved
symptoms
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29. Rotation of BioPoly Implant
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30. Failed BioPoly Implant
• Why? No structural or technical problems identified. No infection. Patient selection? Surgical technique?
• Very difficult to remove! Revised successfully with deep subchondral drilling + ChondroTissue patch.
• Possible reasons: inadequate osseous support (previous microfractures + failed MACI = failure of implant
to bone integration). Good subchondral bone is essential.
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31. OrthoBiologics vs Metal and Plastic
Hmmm ... not really. Not so soon, but will happen ... 31

32. Orthopaedics vs OrthoBiologics
The next stage: new developments which may delay or avoid more invasive surgical
treatments. The future of orthopaedics: basically, less carpentry, more biology?
Conclusion: metal and plastic are not the way forward. Partial
resurfacing implants have limited primary indications and can be very
useful as a bail-out option for failed cartilage repair procedures