Orthopaedics in vitro. The bone marrow content affected fibrochondrocyte

Orthopaedics
review

Future perspectives:

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Among all the methods currently used to repair
meniscus, we have not yet found the ideal solution 1. Tissue adhesives have a
lot of potential to replace or support sutures and staples. Many new adhesive
materials with a good prognosis for use in a variety of applications have been
developed. Most of them however have not been characterized sufficiently to
qualify them as being suitable for meniscus repair. Nevertheless, chemically
cross-linked adhesives seem the most versatile and promising as these are based
on existing natural/synthetic polymers and can be modified. You can adjust the
properties by careful molecular design and chemical functionalization to make
them more suitable for the intended application 2. Standard biomechanical and
biological models should be defined to compare different available and developed
tissue adhesives, and to allow scientist to address their suitability for the
repair of meniscal tears. The most successful treatment in clinical practice
remains the use of sutures. There is a need for a suitable meniscus tissue
adhesive. Adhesives should be easily applied in a tear, have a strong bind with
meniscal tissue, hold torn regions together, facilitate healing, and then
gradually degrade into non-toxic products. Another study demonstrates the development
of a bone marrow adhesive that binds, stabilizes, and stimulates fusion at the
interface of meniscus tissues. Hydrogels containing several chondroitin sulfate
adhesive and bone marrow were formed to investigate the effects of these
components on hydrogel mechanics, bovine meniscal fibrochondrocyte viability,
proliferation, matrix production, and migration ability in vitro. The bone
marrow content affected fibrochondrocyte viability, proliferation, and
migration positively while the chondroitin sulfate content affected adhesive
strength sufficiently 3. Selected material formulations were translated to a
subcutaneous model of meniscal fusion using adhered bovine meniscus explants
implanted in athymic rats and evaluated over three months. Fusion of adhered
meniscus occurred in only the material containing the highest bone marrow content.
The technology can mechanically stabilize the tissue repair interface and
stimulate tissue regeneration across the injury site. Some studies showed that
further investigation using frog glue could potentially improve meniscal
repairs substantially 4.

Surgical techniques & equipment:  

When surgery is looking likely the0nature of0the tear is important.
First the surgeon must consider the zone of the injury (red-red, white-red or
white-white), stability and type (radial/ horizontal/ longitudinal) before
deciding on the form of surgery offered 5.              Knee0arthroscopy is used in diagnosis and0treatment in a number of
knee injuries and disorders, meniscal tears is one of the most common uses.
Under normal conditions the menisci, c-shaped0pieces of cartilage resting between the0tibia and the fibula
provide stability and cushioning for your knee joint. Injuries or things like arthritis
can cause0the menisci
to become torn, this results in knee pain, swelling and diminished range of
motion 6. Knee arthroscopy is normally preformed to remove the damaged
portion of the0meniscus.
An arthroscopic meniscectomy usually takes between045 and 90 minutes. The surgeon gains access
to the knee joint by using sharp instruments called0trocars to make02-3 small openings or ports. The surgeon
will then inject sterile solution into the joint to push the surfaces apart,
allowing the structures inside the joint to be viewed more easily. Next the
surgeon will insert the arthroscope and other instruments through the various
ports. Images from the arthroscope’s camera are magnified and projected onto a
video monitor. Your surgeon will carefully examine the inside of the knee
joint, locate the damage, remove and loose or severely injured parts and use a
shaving instrument to remove any jagged edges 7. While it may be possible to
repair the meniscus with small stitches in most cases the damaged portion must
be removed. At the end of the procedure, the surgeon will again carefully
examine the entire knee for any areas of bleeding or any other damage, remove
the arthroscope and other instruments and close each of the keyhole incisions
with a few sutures.

Current guidelines for repairs: 

The main recommendations are meniscal
repair should only be used to heal peripheral meniscal lesions affecting
healthy meniscal tissue (injury) in vascularised areas (red-red zone or
red-white zone). The current trend is towards use of hybrid implants (fixation
material combined with suture wire) and an exclusively arthroscopic technique. Traumatic
meniscal lesions do not always require a meniscectomy; no surgery or meniscal
repair should systematically be considered. The assessment and management of
non-traumatic degenerative meniscal lesions depend on the extent of cartilage
damage. All ACL ruptures do not require reconstructive surgery. The indication
for reconstruction is based on symptoms, in particular functional instability.
As far as acute ACL injuries are considered, reconstruction by arthroscopy
should preferably be delayed to reduce the thromboembolic events or joint
stiffness. Bone-tendon-bone graft and hamstring tendon reconstruction give
similar results. Lateral tenodesis should be limited to specific cases 12.

1 which meniscal repair techniques are available.

2 How to treat a traumatic lesion

3 How to diagnose and treat a non-traumatic
meniscal lesion

4 what are the indicators for ACL reconstructions

5 which ACL reconstruction techniques are available

The principle
underlying these three questions is meniscal preservation (meniscal repair or
no surgery) or partial arthroscopic meniscectomy. Questions 4 and 5 address the
treatment indications for an ACL tear and the techniques used. The patients
concerned by these guidelines are adults (mature skeleton) suffering from:

The guidelines are
intended for orthopaedic surgeons, general practitioners, physical medicine and
rehabilitation specialists, radiologists, rheumatologists, and
physiotherapists.

Success rates for various treatments:

Some of the differences in the knee joint after meniscectomy
include ridge formation, narrowing of the joint space, and flattening of the
femoral condyle. Investigations suggest0 that these changes are due to the reduced weight-bearing
function of the meniscus.0Meniscectomy
is not wholly innocuous; it interferes, at least temporarily, with the
mechanics of the joint.0It
seems viable that narrowing the joint space will lead to early degenerative
changes, but a connection between these appearances and later osteoarthritis is
not yet proven and is too indefinite 10.0Clinical trials have demonstrated improved functional
scores in patients who have been implanted with Actifit 11 there is a 90%
success rate for arthroscopic surgery to remove a part of the meniscus.
Over time, the success rate reduces following the surgery due to having
less meniscus cartilage.

How age or other factors can affect outcomes:

Patient factors like age, weight, existing knee joint
stability, current mobilization requirements for daily activities and likely
compliance to post rehabilitation instructions are crucial in the decision
making process. Surgeon related factors take into account the experience of the
surgeon in meniscal repair/replacement 5.  213 patients in a recent study0with uncomplicated meniscus
injuries were examined from ten to thirty years after their meniscectomy in
order to help determine the late effects of surgery. Delay of operation after
injury did not affect the final result. Patients below the age of twenty years
old at the time of operation had less excellent or good results.0The diagnosis is more difficult, and the
benefit of meniscectomy is less certain in women than men. The results were
very similar between total and partial meniscectomy except in bucket-handle
tears. The best results occur by leaving the peripheral rim intact in
uncomplicated bucket-handle0tears.
Participation in non-contact sports or persistence in a physical occupation seems
not to alter the course after meniscectomy. It was usually possible to
correlate roentgen-graphic appearance with the clinical result. The
meniscectomy site was readily apparent in 85% of patients. 68% of patients had
satisfactory clinical results, but only 45% of men and 10% of women had symptom-free
knees 8.0Meniscectomy
has frequently been performed on the assumption that the absence of a meniscus
has little effect on joint function.0Statistical analysis of data obtained from the histories,0physical examinations,
and roentgen-graphic and electro-goniometric studies of 99 patients revealed a
high incidence0 of
poor results, degenerative arthritis, ligamentous laxity, and decreased
stance-phase flexion.0A
meniscus should be removed only when it is definitely abnormal 9. The
financial costs of meniscal replacements will also0influence whether they can be offered to
patients as hospitals might not be able to afford these costly implants
estimated at almost 2000 Euros per unit05.

References:

1 Fox, A.J., Bedi, A. and Rodeo, S.A., 2012. The basic
science of human knee menisci: structure, composition, and function. Sports
health, 4(4), pp.340-351.

2 Bochy?ska, A.I., Hannink, G., Grijpma, D.W. and Buma, P.,
2016. Tissue adhesives for meniscus tear repair: an overview of current
advances and prospects for future clinical solutions. Journal of Materials
Science: Materials in Medicine, 27(5), p.85.

3 Simson, J.A., Strehin, I.A., Allen, B.W. and Elisseeff,
J.H., 2013. Bonding and fusion of meniscus fibrocartilage using a novel
chondroitin sulfate bone marrow tissue adhesive. Tissue Engineering Part A, 19(15-16),
pp.1843-1851.

4 Szomor, Z.L., Murrell, G.A., Appleyard, R.C. and Tyler,
M.J., 2008. Meniscal Repair With a New Biological Glue. Techniques in Knee
Surgery, 7(4), pp.261-265.

5 D Lin, D., E Picardo, N., Adesida, A. and S Khan, W.,
2017. Clinical studies using biological and synthetic materials for meniscus
replacement. Current stem cell research & therapy, 12(4),
pp.348-353.

6 Bonutti, P.M., Mont, M.A., McMahon, M., Ragland, P.S. and
Kester, M., 2004. Minimally invasive total knee arthroplasty. JBJS, 86(suppl_2),
pp.26-32.

7 Burman, M.S., Finkelstein, H. and Mayer, L., 1934.
ARTHROSCOPY OF THE KNEE JOINT. JBJS, 16(2), pp.255-268.

8 Tapper, E.M. and Hoover, N.W., 1969. Late results after
meniscectomy. JBJS, 51(3), pp.517-603.

9 Johnson, R.J., Kettelkamp, D.B., Clark, W. and Leaverton,
P., 1974. Factors Affecting Late Results after Meniscectomy. JBJS, 56(4),
pp.719-729

10 Fairbank, T.J., 1948. Knee joint changes after
meniscectomy. Bone & Joint Journal, 30(4), pp.664-670

11 Verdonk, P., Beaufils, P., Bellemans, J., Djian, P., Heinrichs,
E.L., Huysse, W., Laprell, H., Siebold, R. and Verdonk, R., 2012. Successful
treatment of painful irreparable partial meniscal defects with a polyurethane
scaffold: two-year safety and clinical outcomes. The American journal of
sports medicine, 40(4), pp.844-853

12 Beaufils, P., Hulet,
C., Dhenain, M., Nizard, R., Nourissat, G. and Pujol, N., 2009. Clinical practice
guidelines for the management of meniscal lesions and isolated lesions of the
anterior cruciate ligament of the knee in adults. Orthopaedics
& Traumatology: Surgery & Research, 95(6), pp.437-442

 

 

 

 

 

Classification
of devices.

Briefly
describe the implications in terms of the regulatory process for each 

The reason for regulatory control of medical devices is
to ensure patient safety. The authorities in various countries monitor and
control manufacturing companies to ensure safe and effective products are
delivered into the market place with appropriate risk- benefit ratios.
Engineers must be familiar with regulatory requirements so they can achieve
market approval for a device. The reason classification is so important is
because it determines the regulatory pathway for the medical devices. For a
class I device the pathway is much more easy and quick than the complex,
expensive Class III pathway. A medical device quality system is designed to
assure products are appropriate for their use and always meet the
specifications defined by clinical results. The achieve approval for a device
the company must put in place a quality system to be audited and certified by a
notified body. For example, a company could not sell a medical device in the EU
until it has been certified.

Fine needle aspiration:

Intended use

Rule

Class

Thin
bore needle

7

IIa

Non-invasive
collector dish to take samples

1

I

Non-invasive
ultrasound transducer

1

I

 

Mammotome (Vaccum assisted core biopsy device):

Intended use

Rule

Class

Syringe
to inject anaesthetic

6

I

Metallic
mandrel to extract the sample

7

II

Biocompatible
cannula

1

I

Chamber
for the collection of samples

1

I

Suction
tubes

1

I

 

Ventouse (vaccum extractor):

Intended use

Rule

Class

Specially
designed cup of specific diameter

1

I

Rubber
tube to attach cup and a glass bottle (with screw to release negative
pressure)

1

I

Manometer
fitted in mouth of bottle to declare the negative pressure

1

I

 

Classification of medical devices is based on risk. As
soon as possible in the design stage the manufacturer must decide which class
their device is in. Class I, IIa, IIb and III are the four types of classes
that represent low risk, medium risk, higher risk and highest risk. The act
requires FDA to determine safety and effectiveness of a device by weighting any
probable benefit to health from the use of the device against any probably risk
of injury/illness from the use. The small set of criteria includes the duration
of body contact, the invasiveness degree and the local vs. systemic effect.
However this all depends on the intended use. The devices are categorised under
the each rule and the each rule consists of sub categories each a risk based class.
Although these rules will adequately classify the vast majority of existing
devices, a small number of difficult cases can arise. For example determining
the boarderline between two classes. There are also devices that cannot be
classified due to their unusual nature and classifying them would result in the
wrong level of conformity assessment in light of the hazard represented by the
device.

Rule one is for devices that either come into contact
with intact skin or does not even touch the skin only. It acts as a fall back
rule for any device not covered by a more specific rule. Non-invasive devices
are in Class I. For example, corrective glasses and frames.

Rule two is for types of devices that may be indirectly
invasive. They channel/store substances that will eventually be administered
into the body. A typical example would be found in the delivery of anaesthetic
gases and oxygen. Class IIa is for anything intended for storing substances
that will be eventually introduced into the body. In any other case they are in
Class I.

Rule three is the non-invasive devices that modify
biological/chemical composition of blood, body liquids or other liquids intended
for infusion. They must be separate from the non-contact rule 1 devices as they
are indirectly invasive. The modify substances that will be infused into the
body for example dialysis systems. All devices for modification are in Class
IIb unless the treatment consists of filtration, centrifugation or gas exchange
in which they are lower risk in Class IIa.

Rule four is for non-invasive devices which come into
contact with injured skin, ie: to cover wound dressings. Class I is for use as
any mechanical barrier, compression or absorption. Class IIb is they are to be
used with wounds and can only heal by secondary intent, ie: dressings for
chronic extensive ulcerated wounds. Devices are in IIa in any other case. Rule
5 is for devices invasive with respect to body orifices. Rule 6 explains
surgically invasive devices intended for use under 60 minutes. Rule 7 and 8 are
similar but intended for short-term and long-term use.

 

 

 

 

 

 

 

Risk
analysis.

(1) Mammotme device:

Classification of risk

Severity if it occurs

Probability of occurrence

Risk factor

Why is it a risk

Scaring

2

2

4

Patients can be unsatisfied if left with a larger scar
than the ¼ inch incision expected.

Sample size

4

2

8

Insufficient sample size will lead to uncertain diagnostic.

Penetration of vital organs

5

1

5

Difficult to collect sample tissue closer to the chest
wall.

Patient motion

3

2

6

Movement of the patient will make it more difficult to
collect accurate sample.

Clip migration

3

3

9

If future needle localization is required incorrect
target sites will occur.

 

Risk

Risk factor

Control action

Scaring

4

Well trained surgeons that are familiar with the device
should only be allowed to operate. There should be no large scaring if the
device is used steadily and controlled.

Insufficient sample size

8

Highly trained surgeons must be familiar with using the
gentle vacuum suction correctly, the precision of the needle can be less
accurate and still manage to obtain target tissue with the assisted vacuum.

Penetration of vital organs

5

Lesions closer to the chest area should require extra
care when extracting sample tissue. Workshops should be carried out to ensure
staff are trained efficiently to carry out these more difficult procedures.

Movement

6

Again using special table to impede movement and obstruct
vision as this can also cause vasovagal reactions.

Clip migration

9

As this is inevitable in fatty tissue, applying
compression to the area prior to implantation can help prevent drastic
migration and measure the displacement more accurately.

 

 

 

 

 

(2) Ventouse device:

Classification of risk

Severity if it occurs

Probability of occurrence

Risk factor

Why is it a risk

Intracranial haemorrhage

5

2

10

Any force exerted too high is not safe for the baby’s
health and potentially fatal.

Lower genital tract tears

4

3

12

Cause pain and discomfort for the mother. Potentially prohibit
delivery process.

Swelling around cup

4

2

8

Harm or deform the child’s head. Potentially harm intracranial
organs or cause minor capillaries in the head to burst

Neonatal jaundice

4

3

12

Can lead to toxic health implications if bilirubin
leads to the brain.

Incorrect cup positioning

4

2

8

If positioned wrong, delayed labour can occur along
with potential skull damage.

Shoulders getting stuck

4

2

8

The baby could be injured as well as causing huge
discomfort to the mother.

Fracture or breaking of the tube

5

2

10

Results in total termination of the assisted delivery.

 

Risk

Risk factor

Control action

Intracranial haemorrhage

10

Ensure the device is on for the least amount of time
possible and positioned correctly. If the baby has any known health
conditions the device should not be used.

Lower genital tract tears

12

Ensure the mother’s pelvis s orientated correctly and
the device is on securely.

Swelling around the cup attachment

8

This is inevitable, parents should be made aware of
possible side effects and after care must be correctly carried out.

Neonatal jaundice

12

If the baby has an underdeveloped liver the device
should not be used. Only use for short periods of time and when necessary.

Incorrect cup positioning

8

Have highly trained physicians and surgeons use the
device. Organise regular workshops to teach new staff and current staff any
update or changes in how to use it.

Shoulders getting stuck

8

Only use the device if the baby is in the correct
orientation. Again have well trained staff carry out the procedure.

Fracture or breaking of the tube

10

Carry out multiple fatigue tests and ensure safety
checks are done regularly. Any old/out of date devices that no longer
function at optimal level should be disposed or fixed immediately.