Knee Osteoarthritis
Muhammad Ihsan
Hip & Knee Surgeon
Introduction
OA was exclusively a degenerative disease of the cartilage,
however, latest evidence has proven that OA is a
multifactorial entity, involving multiple causative factors
like trauma, mechanical forces, inflammation, biochemical
reactions, and metabolic derangements.
OA is classified into two groups according to its etiology:
primary (idiopathic or non-traumatic) and secondary
(usually due to trauma or mechanical misalignment)
Epidemiology
OA affects around 250 million people worldwide2 and more than 27 million
people in the United States.3,4 Elderly (approximately 35% of patients over 65
years old) females, patients with obesity and African Americans are the
population with the highest risk of developing OA
While in Indonesia, the prevalence of osteoarthritis at the age of 61 years is
5%. Meanwhile, the prevalence of knee osteoarthritis is still quite high in
Indonesia, which account 15.5% in men and 12.7% in women of the total
Indonesian population which amounts to 255 million people (Koentjoro, 2010).
Anatomy
Knee is composed by osseous
structures (distal femur,
proximal tibia, and patella),
cartilage (meniscus and hyaline
cartilage), ligaments and a
synovial membrane
Imaging
Non-pharmacological
management
Exercise routines should be tailored to every patient’s needs, high
impact activities should be avoided, and long-term adherence should be
maximized
Aquatic (water-based) therapies provide an alternative to patients who are
hesitant to start land-based exercises, given the lesser joint impact
Weight management : The adipose tissue itself is a source of inflammatory
factors and the Knee is the joint that support 3-5 times body Weight
Patient might benefit from thermal modalities, but there is insufficient
evidence to recommend the use of transcu-taneous electrical nerve
stimulation (TENS) or therapeutic ultrasound.
Hamstring stretch
Calf stretch
Straight leg raise
Quad set
Pharmacological
management
Historically, cyclooxygenase inhibitors (acetaminophen and
NSAIDs) have been the most commonly used
medications.
But given the gastrointestinal, renal, cardiac, and
hematological adverse effects of these medications, their
long-term use is limited.
Acetaminophen has shown to be inferior to NSAIDs and not
superior to placebo for pain control, leading to some
guidelines to abstain to recommend it as an effective
medical management strategy for moderate-to-severe OA.
If a patient is refractory to other treatments and the use
of an opioid is considered, Tramadol, has shown some
benefit in the treatment of severe and moderate OA.
This medication, compared to other opioids, has
slightly less risk for abuse potential and respiratory
depression.
Interventional management
will show less systemic adverse effects and
depositing the medication inside the joint will have a
more direct effect.
Studies have shown that in general IA therapies are
more effective than NSAIDs and other systemic
pharmacologic treatments, but they also disclosed that
a percentage of that benefit might be secondary to IA
placebo effect.
Supra patella injection
Currently, the available FDA approved Immediate
Release (IR) corticosteroids for IA usage are:
Methylprednisolone Acetate , Triamcinolone Acetate,
Triamcinolone Hexacetonide , Betamethasone Acetate,
Betamethasone Sodium Phosphate & Dexamethasone
Dosages equivalent or higher than 50 mg of prednisone
(equivalent to 40 mg of Triamcinolone acetate and
Methylprednisolone Acetate) seems to be linked to a
longer pain relief effect of 12–24 weeks
OARSI and ACR guidelines support their use, while the
AAOS considered to against them
Controversies related steroid
IA injection
Some studies suggest that there is no alteration in
the cartilage structure, while others suggest that
Steroid injection can promote chondrocyte
destruction and increase the necessity for joint
replacement
A portion of the IA Steroid is absorbed systemically, with
the possibility to produce hypoglycemia and transiently
affect the hypothalamic-pituitary-adrenal (HPA) axis in
up to 25% of the patients.
Non-Corticoid interventional
therapies
In the OA knee the concentration and the molecular weight of the HA
decrease considerably, and that is why some proposed to
viscosupplement the joint in an attempt to restore the HA benefits.
The current evidence regarding efficacy is conflicting and in result,
there is variation regarding recommendations from the societies. The
AAOS does not recommend its use, the ACR has no recommendations
about it,the OARSI has an “uncertain recommendation.
a recent European consensus stated that HA was well tolerated and
effective for low and moderate grade OA.Lastly, this treatment might be
more effective in patients with higher levels of knee pain, younger and
with lower KL score
Bracing can offer stability and increase confidence
Some evidences suggest that bracing can help reduce
symptoms and improve function
But more recent studies have demonstrated less of
benefit
Knee osteoarthritis management
recommendations from societies
High Tibial Osteotomy
Indications
•Isolated Compartment OA
•Less than 12 degrees
deformity
•Stable knee
•Young and active
Benefits
•Avoid arthroplasty
•No limits on activity
Problem
Inconsistent results – 50% still effective at 7-10
years
–At 5 years 75% good or excellent.
–At 8 years 60% good or excellent.
–(Arch Orthop Trauma Surg 124:258-261, 2004)
•Arthroplasty after osteotomy may not be as
successful.
•Certainly more challenging surgery.
Unicondylar Knee
Arthroplasty
Indications
•isolated compartment
Osteoarthritis.
Benefits
•Smaller incision, Quicker
recovery, better feeling
knee, cost implications.
Problems
•progression, revision.
How long they last
Swedish Register –
about 90% at 10
years
Total Knee Replacement
91-96% prosthesis survival
rate at 14-15 years of
follow-up.
•We now know that
approximately 85 percent
of the knee implants will
last 20 years.
•Thus most implants will
last a life time
“Thank you.”
