This document provides an overview of osteoarthritis (OA) and treatment options that may delay or avoid surgery. It discusses trends in treating OA as a biological condition rather than only as mechanical wear and tear. New developments mentioned include treating the whole osteochondral unit with subchondral drilling or nanofracture instead of just cartilage repair. Stem cell injections and regenerative medicine are presented as promising future options. The document emphasizes treating early cartilage damage and bone bruising before they advance to end-stage OA requiring joint replacement.

1. 2023 Update on Knee OA
Osteo-arthritis & Osteo-arthrosis
Orthopaedics & OrthoBiologics
New trends and developments which may delay or avoid surgical treatments
Vladimir Bobić, MD FRCS Ed
Chester Knee Clinic at Nuffield Health, the Grosvenor Hospital Chester
www.kneeclinic.info office@kneeclinic.info @ChesterKnee
Department of Sport and Exercise Sciences
Chester University
MSc Sports Medicine, Module SS7341
Monitoring and Managing Athlete Injury and Illness
2nd March 2023

4. My practice is based at Chester Nuffield since 1997.
Knees only, 50% private, 50% NHS

7. So, less (orthopaedic) carpentry and more biology

8. MARIARC MRI, UK (1997)
The orange pixels correspond to normal T2 values for bone. The blue and
purple pixels are anomalous: the T2 relaxation times are elevated because the
tissue is "wetter" than normal (the fluid interface between recipient and
donor bone).
OAT MRI analysis
MR Imaging Protocol 1997: Dr David Ritchie, Consultant Musculoskeletal Radiologist, Liverpool (now Glasgow), UK

9. “Chronic” BME and Cartilage Delamination
CKC UK

11. ICRS Standards Workshop 2000, Schloss Münchenwiler, Switzerland, January 27 -29, 2000
ICRS ARTICULAR CARTILAGE IMAGING COMMITTEE
ICRS MR Imaging Protocol for Knee Articular Cartilage
By Vladimir Bobic, MD
The Royal Liverpool University Hospital, Broadgreen Hospital Knee Service
newsletter 2000, III, p. 12
Introduction
Articular cartilage lesions are common and impor-
tant clinically. New treatment modalities have
mandated a non invasive method of imaging artic-
ular cartilage.
MR imaging is the best non invasive modality to
image articular cartilage. MR has been shown to
be highly accurate in assessing morphology. This
is useful in diagnosing diagnosing chondral
lesions (with sensitivities and specificities in the
80-95% range in the knee) and in the assessment
of post operative repair tissue.. The biochemical,
histologic and clinical correlates of this mor-
phologic information remains an active research
area. We believe that cartilage imaging should
be a part of every MR exam of the knee. A carti-
lage specific sequence like those described below
should be performed in the sagittal plane on every
patient. If a chondral lesion is found, additional
sequences in other planes may be added to more
fully define the lesion.
Technique of MR imaging of cartilage
The two types of MR sequences that have been
found to be the most accurate in detecting car-
tilage abnormalities are fast spin echo (FSE)
sequences and a fat suppressed T1weighted 3D
gradient echo (FS T1W GRE) sequence. Here are
examples of such images:
Each sequence has unique advantages and dis-
advantages. Two advantages of FSE sequences
are:
1. the acquisition of high-resolution images with
a short image time and
2. improved image contrast by the generation of
an MT effect when using a multislice acquisi-
tion due to off resonance excitation resulting
from multiple refocusing pulses. (1).
A number of recent articles have demonstrated
high sensitivity and specificity of FSE sequences
in the evaluation of articular cartilage in the knee
(2-4). FSE sequences are equally effective whether
using proton density or T2 weighting and or fat
suppression. Fat suppression can improve the
assessment of the subarticular bone marrow for
edema and reduce chemical shift artifacts. Car-
tilage defects appear as areas of signal abnor-
mality within the articular cartilage on FSE images.
The second sequence that has been shown to be
accurate in detecting cartilage pathology is a fat-
saturated T1W GRE sequence (5,6-8). The use of
fat suppression increases the dynamic range of
signal intensities within the articular cartilage
allowing the detection of more subtle changes in
signal intensity. Two additional benefits of fat
suppression are the elimination of chemical shift
artifact and the reduction of motion-induced
ghosting artifact from extraarticular fat signal.
On FS T1W GRE images there is high contrast
between bright cartilage and relatively dark fluid,
bone, fat, and muscle. The FS T1W GRE images
are relatively insensitive for assessment of mar-
row edema and subchondral cysts because both
fluid and marrow appear dark. Cartilage is high
in signal compared to low signal fluid because of
the T1-weighting of this sequence. The intrinsic
signal intensity onT1W 3D GRE images is uniform
throughout the thickness of the cartilage; how-
ever, truncation artifacts can produce low signal
laminae in the mid-portion of the cartilage which
do not interfere with image interpretation (9).
Although increasing the resolution of the images
can eliminate truncation artifacts, the resultant
decrease in the signal to noise requires longer
image times that are not practical in clinical prac-
tice. However, truncation artifacts have not been
a detriment to identification of cartilage lesions
in our experience and, in fact, can be a helpful
marker in assessing the depth of focal cartilage
defects. A number of studies have documented
the high accuracy of the FS T1W GRE sequence
for the detection of chondral abnormalities (5,6-
8). Cartilage abnormalities are routinely seen as
contour defects with this sequence, unlike FSE
images which, as stated above, appear as signal
abnormalities.
Specific advantages and disadvantages
FSE sequences are less sensitive to magnetic sus-
ceptibility artifacts (which can be an advantage
forpatientswhohaveundergoneprevioussurgery)
than the FS T1W GRE sequence, and they can be
usedtoaccuratelydetectassociatedmeniscaland
ligamentous pathology. Choices in instrument
materialsandsurgicaltechniquetodecreasemetal-
lic debris should be considered a high priority
amongsurgeonsandmanufacturers.The3Dnature
oftheFST1WGREsequenceallowstheuseofmul-
tiplanar reconstructions and, in most instances,
thinner slice thicknesses, which are often impor-
tantinevaluatingthecurvedsurfacesofjointsand
theabilitytoperformvolumemeasurements.There-
fore,iftimepermitsuseofbothtypesofsequences
are recommended to assess articular cartilage.
We have listed parameters that have been found
useful for FSE and FS T1W GRE sequences. In
Appendix A. All of these sequences can be per-
formed on commercially available state of the art
scanners. We recommend if possible to perform
cartilage imaging on magnet strengths of 1.0 T
and greater.
One possible protocol for a knee MR examina-
tion tailored specifically for cartilage consists of
the FSE proton density sequence acquired in the
coronal plane, the fat suppressed T2 weighted
FSE in the axial plane, and the FS T1W GRE in the
sagittal plane. The GRE sequence can be recon-
structed in the coronal and axial plane as well.
For postoperative patients the FS T1W GRE
sequence can be problematic secondary to sus-
ceptibility artifacts and more emphasis should
be placed on the FSE sequences. It should be
remembered that the above protocol is for artic-
ular cartilage imaging. A sagittal proton den-
sity/T2 Weighted sequence (conventional spin
echo or FSE) should be added to evaluate for
meniscal and ligamentous pathology.
MR evaluation
At this point MR evaluation is mainly based on
morphology and signal intensity changes. A
means for documenting changes are being cod-
ified into the ICRS MR grading scheme. Parame-
ters will include depth, size and location of lesion,
and signal intensity changes. Cartilage thickness
and volume measurements have been validated
in the knee and in small joints of the hand and
play an important role in the serial assessment
of patients (Image analysis protocols to be
included in Appendix B).
Image Distribution
The utility of MR will be greatly enhanced with
the ability to electronically distribute images to
referring physicians and consultants. This needs
to be cost effective and reliable.
A practical and acceptable method at the current
time is to take digital images of film using a dig-
ital camera (preferably above 2 megapixel reso-
lution) and saving the image as a JPEG file.
In the future, direct digital capture of images and
distribution over the internet in a DICOM(stan-
dard radiology digital image format) format should
be achievable.
Research and future technologies
While MR imaging has been well demonstrated
to provide morphological information, the histo-

12. What are we going to talk about today?
The entire presentation will be available on:
www.slideshare.net/vbobic

13. Knee Osteoarthritis:
Overview and Treatment Options
Osteoarthritis is a degenerative joint disease that is
increasing in prevalence, and the knee is the most
commonly affected joint.
Factors such as increased incidence of obesity and
participation in sports, as well as the ageing of the
population, may contribute to this increased
prevalence.
The treatment options for osteoarthritis, which
range from conservative treatment options to
surgical intervention, have varying degrees of
success, but new therapies are on the horizon.
13

14. Most patients in my practice do not have classic OA, as progressive, destructive
inflammatory disease of the entire knee joint and most of the time they do not have OA
of any other joint(s).
Most of my patients have one bad knee, usually the medial or patello-femoral side of it,
because of trauma, sports, work, etc. and they develop meniscal, chondral and ligament
injuries which in turn cause accelerated wear and tear (which is different from
inflammatory nature of classic OA and RA) and subsequent reactive synovitis and
subchondral degeneration resulting in stiff subchondral plate and further damage to
articulating surfaces.
Most of those people respond well to arthroscopic surgery, including deep subchondral
drilling (which seems to re-establish osteochondral nutritional and other communication
channels, which is the same reason why microfracture works for some people) and other
arthroscopic treatments, which does not work well in OA and RA knees.
So, there is a difference, if we think about this as accelerated wear and tear (known
as gonarthrosis or osteoarthrosis in many European countries or PTOA in the USA),
which most people have, vs “classic” OA (as inflammatory multi-joint disease).
This is, perhaps, too simplistic and even scientifically naive but that is my impression,
based on my clinical experience over the past 30+ years in the UK, but let’s talk about it:
OsteoArthritis or OsteoArthrosis?
or just accelerated wear and tear?

15. Sports Knee Injuries and OA

16. Mucoid ACL Degeneration, ACL
Ganglions & Subchondral Cysts
(an update from ACL SG Åre, Sweden, 2016)
Vladimir Bobić, MD, FRCSEd
Consultant Orthopaedic Knee Surgeon
Chester Knee Clinic, Chester, UK
ACL Study Group 2023
St Kitts, 29th January to 2nd February 2023

18. Cross-talk Between Articular Cartilage,
Subchondral Bone and ACL
• Our focus now is on the role of enthesitis which seems to be the key to the start of the
inflammatory and subsequently degenerative processes of the ACL.
• MRI analyses indicates that the localization of bone marrow oedema in early OA is
often associated with ligament attachment site, the enthesis, which seems to play a
central role.
• The intimate cross-talk between synovitis, articular cartilage, ACL and
subchondral bone is no doubt the main feature of MDACL.
• The aetiology is also suggestive of disrupted neuromuscular network and joint
homeostasis at several intra-articular levels.
CKC UK

20. Ageing and OA: An inevitable Encounter?
T Huegle et al.: Ageing and OA - An Inevitable Encounter? JAR 2012

22. OsteoArthritis vs. OsteoArthrosis vs. PTOA
CKC UK 22

27. A Landmark 2022 Publication:
OPTIKNEE 2022 Consensus
meeting and recommendations
aimed at promoting knee health
and prevention of PTOA

29. Articular cartilage + Subchondral plate + Trabecualar bone are
biologically and functionally inseparable OsteoChondral unit
which absorbs and distributes loads across the joint.
CKC UK
We can not think and act in monolayer terms. Articular cartilage (surface)
repair is not good enough. We have to think and act in 3D terms!

30. Osteochondral Functional Unit
Source: Dr Carl Winalski, Boston, USA, 2003

31. Sports Knee Surgery Symposium
The University of Warwick
3 and 4 November 2003
Bone Bruise and Bone Marrow
Oedema: The Bad News
for Articulating Surfaces
Vladimir Bobic, MD FRCSEd
Consultant Orthopaedic Knee Surgeon

32. Well, not exactly a brand new concept:
Source: Francis Berenbaum, 3 November 2016

33. Nothing New!
Source: Francis Berenbaum, 3rd November 2016

34. JBJSA March 1974

35. The Structure of Subchondral Bone
Redrawn from: Imhof H, Breitenseher M, Kainberger F, Rand T, Trattnig S. (1999): Importance of subchondral bone to
articular cartilage in health and disease. Top Magn Reson Imaging 10:180–192
A surprisingly high number of arterial and venous vessels, as well
as nerves, can be seen in the subchondral region sending tiny
branches into the calcified cartilage …

36. The Structure of Subchondral Bone
• This is extremely important for cartilage repair: the
tidemark is crossed by collagen fibrils extending
from the articular cartilage into the calcified
cartilage, while no collagen fibrils connect the
calcified cartilage to the subchondral bone plate.
• Blood vessels from the subchondral region can extend into
the overlying calcified cartilage through canals in the
subchondral bone plate.
• Therefore, nutrients can reach chondrocytes in the
calcified zone via these perforations.
• Unsurprisingly, the perforations are grouped
together in the regions of subchondral plate where
the stress is greatest.
CKC UK

37. The Structure of Subchondral Bone
The changes in the thickness of the subchondral bone plate depends on the
location and mechanical loads
Henning Madry, Saarland University, Homburg/Saar, Germany

38. From Minor Cartilage Damage to Advanced OA
... to Advanced Medial OA?
From a Small MFC Chondral Lesion ...

39. Biological Treatment Options:
Oral Supplements (Glucosamine + CS)
Viscosupplement Injections
Shockwave Therapy (SWT)
PRP Injections
Autologous Stem Cell Injections
Arthroscopic Subchondral Drilling
Nanofracture with Intra-osseous Injections
AMIC (nanofracture site covered with membrane)
ChondroTissue (scaffold)
OATS with Autologous Bone Marrow Aspirate
ACI (Autologous Chondrocyte Implantation)
39

40. Physiotherapy Better Than Steroid injections!

41. Beware of Intra-articular Steroid injections!

42. Oral Supplements: Glucosamine and Chondroitin Sulphate

43. Oral Supplements: Glucosamine and Chondroitin Sulphate

44. Hyaluronic Acid Injections

45. Hyaluronic Acid Injections

46. 1st Orthopaedic Stem Cell Seminar in the UK

47. Too old for stem cell therapy? Probably not!
Cell apoptosis and senescence do exist but basic biological
healing principles persist.
“Youth would be an ideal state if it came much later in life.”
Herbert Henry Asquith

48. “The first great advancement in sports medicine was the arthroscope, the second is going to be
this (stem cells).” James Andrews, MD, “The Athlete’s Surgeon”, Birmingham, Alabama, USA

49. 2017
2017
OrthoBiologics or BioOrthopaedics

50. What are Mesenchymal Stem Cells?
• Adult stem cells can help
regenerate many tissues
• The best source is the
autologous tissue
• Many different tissues can be
used to process biologically
powerful stem cells
• It seems that the best tissue to
extract MSC is SVF (stromal
vascular fraction) adipose
tissue, which is the best source of
cells and regenerative factors

51. Regenerative Medicine - Stem Cell Technologies

52. Well, MSCs are NOT Stem Cells!

53. The MSC: an injury drugstore

54. MSCs and Blood Vessels

57. Stem Cells No Better Than Placebo … So Far
(Editor of Arthroscopy Journal re JBJSA September 2016 Article)

59. PRP Today

60. Arthroscopy Journal, article in press, 2015

65. Osteochondral Repair and OA: Surgical Options
ACI BioPoly
UKR & TKR
OATS
Microfracture
Chondroplasty

66. Microfracture
66

67. 67
Nanofracture : deep drilling is better!

68. MFC Microfracture site after 5 years
68

69. 69

70. ACL injury + extensive BB
CKC MRI 110206
7 months later

71. SONK Before and After Subchondral Decompression
(… the road to hell is paved with good intentions …)
• 15/12/08: subarticular insufficiency
fracture and slight flattening of the
MFC and prominent subarticular
marrow oedema more marked on the
femoral side. Since 04/04/08,
significant deterioration in the medial
compartment with SONK-like
process, progressive degenerative
changes …
• 11/09/09: Comparison is made with
the previous scan 15/12/2008. In the
medial compartment, following the
subchondral decompression, there
is now evidence of articular
irregularity, deficiency and
thinning of articular cartilage,
slight increase in the subarticular
marrow oedema and early
subarticular cyst formation in the
outer aspect of the MFC …
• … however, if approached externally
(retrograde drilling) and injected
with autologous bone marrow
aspirate or PRP the outcome could
have been different (but we did not
know that in 2008)

72. The Subchondroplasty
Procedure

73. Frustration after a presentation at Sports Knee 2017
CKC UK 2018

74. The Subchondroplasty Procedure
Great idea, but it seems that this entirely new concept (as it is) is based on huge
assumptions.
Arguably, subchondroplasty is indicated mainly for the treatment of
subchondral cysts and cavities, rather than various bone marrow oedema
conditions.
Bone marrow oedema, as metabolic (vascular) “event” does not lack bone
(therefore injecting bone substitute is not the right ingredient). To the contrary,
injecting bone paste will clog many interconnected cellular spaces and will slow
down or prevent subchondral repair and remodelling. Not surprised to hear that
patients "should expect 3 days of severe pain" (!) as injected and cured bone paste
will increase intra-osseous pressure (which is already higher than normal and which
is why some SONK-like conditions are very painful to start with) and block
metabolic (vascular) pathways!
However, the real biologically desirable ingredient is autologous bone
marrow aspirate (or autologous stem cells or even PRP), delivered to the area
affected with bone marrow oedema.
This is where subchondroplasty becomes a bit more intelligent and gets entirely
new biological meaning and a lot more street cred.
Vladimir Bobic CKC: Articular Cartilage, Subchondral Bone and Osteochondral Unit. 4th BKS Meeting, Cardiff, UK 1-2 February 2018.

75. Frustration after a presentation at Sports Knee 2017
CKC UK 2018

76. OATS Indications:
• The “ideal” chondral lesion is relatively small, full-thickness
defect (10 to 15 mm in diameter), without subchondral bone loss.
• This lesion should be treated early, in an attempt to contain the
defect and to repair the lost hyaline cartilage with hyaline
cartilage.
Osteochondral Autograft Transplantation (OATS)

77. Autologous Osteochondral Grafting (OATS)
77

78. Lateral Femoral Trochlea:
a reliable source of good cancellous bone and bone marrow, even in advanced OA
CKC UK
MFC AVN

79. Autologous Osteochondral Grafting (OATS)

80. “Pre-TKR” option: OATS combined with autologous bone marrow aspirate

81. ACI (Autologous Cultured Chondrocyte Implantation)
periosteal cover
ACI is the very first tissue engineered
orthopaedic (orthobiologic) surgical
procedure
atlas

82. FU MRI: “In the medial
compartment, the graft over the
central weight-bearing portion of
the medial femoral condyle has
incorporated with adjacent
bone and the overlying
articular cartilage is flush
with adjacent native
cartilage. A small focus of
marrow oedema is noted directly
beneath the graft but overall
there has been a reduction in
marrow oedema around the
graft. A small trace of
subcortical fluid in the peripheral
portion of the medial femoral
condyle is similar to the pre-
operative scan - presumably not
included in the repair.”
Dr David Ritchie, Glasgow
CKC MRI 030307

83. ACI/CCI Stage 1: Arthroscopic Chondral Biopsy
CKC Chester UK

84. ACI/CCI Stage 2: Open Implantation
Source: www.geistlich.com

85. Good ACI graft fill, a year after ACI

86. A game changer …

87. Grow your own knee …, well, not really …

88. 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
BioPoly®RS Knee System
The partial resurfacing implant
88

89. Registry Study Results

90. Customised Knee Replacement Implants
Most replaced knees are satisfactory functionally but
they are not a substitute for a normal knee!
Keep what your parents gave you as long as you can!

92. www.slideshare.net/vbobic

93. THANKYOU FORYOUR ATTENTION
VB CKC UK
KEEP MOVING AND LOOK AFTERYOUR KNEES!