CMScript
Issue 9 of 2016
Member of a medical scheme? Know your guaranteed benefits!
Avascular Necrosis
This edition of CMScript focuses on a condition that is not included in the Prescribed Minimum Benefits
(PMB) but may lead to a valid PMB condition. It is written in response to numerous complaints received
from medical schemes’ members and healthcare providers.
by Ronelle Smit - Clinical Analyst
Background
Avascular Necrosis is not included in the PMBs
as a condition itself, but can cause a PMB condition as the disease progresses. This is the first
time that a CMScript focuses on a condition that
is not included in the Prescribed Minimum Benefit
regulations.
What is Avascular Necrosis?
Avascular means insufficient blood supply to a
specific area of the body. Necrosis means the
death of tissue or bone in the body. Avascular
Necrosis is therefore defined as the death of the
bone due to a loss of blood supply. Avascular necrosis is also called osteonecrosis (osteo meaning
bone). The condition is aseptic, meaning that it is
free from harmful bacteria and viruses.
Aseptic
Figure necrosis
1: Aseptic necrosis
As the bone dies it loses its smooth surface and
eventually causes the collapse of the joint. The
condition mostly occurs in the hip joint but can also occur
in the knee, shoulder and ankle joints. The condition may
involve only one side of the body or occur bilaterally and
involve both joints e.g. both hips.
The condition can occur at any age but most often affects
people aged between 30 and 60 years.
Symptoms of Avascular Necrosis
During the early stages of the condition most people do not
suffer from specific symptoms. As the condition progresses,
the affected joint becomes painful.
At first the affected joint may be painful only when some
pressure is put on it, but eventually the pain may occur consistently, even when the person is lying down. The level of
the pain normally varies from mild to severe pain, and gets
worse as the condition progresses. Once the joint collapses the person may have such severe pain that it interferes
with their ability to use the joint and move around. One may
need to use assistive devices such as crutches to move
around.
The period from the onset of the first symptoms to the collapse of the joint differs from case to case and may take
several months or years.
Causes and risk factors for developing Avascular Complications of Avascular Necrosis
Avascular Necrosis gets worse as the disease progresses.
Necrosis
The cause of Avascular Necrosis is not always clear. The As the disease advances the bone loses its natural smooth
condition can affect people who are in complete good shape, leading to severe arthritis, weakening and ultimate
health. There are a few known risk factors that may poten- breaking (fracture) of the bone.
tially lead to Avascular Necrosis.
The treatment for Avascular Necrosis focuses on slowing
down the progression of the disease, including bone loss
The risk factors include:
• Dislocation or fracture of the femur (thigh bone) - the in- and the subsequent crumbling or fracturing of the bone.
jury can affect the blood supply to the bone and lead to
trauma-related avascular necrosis. The condition may Since Avascular Necrosis is not included in the PMB regudevelop in 20% or more of people who experienced lations, the medical and surgical treatment for the condition
will not be discussed in this article.
trauma to the joint, such as dislocation of the joint.
• Chronic use of corticosteroid medicine - long-term use
of these medicines is associated with approximately When will Avascular Necrosis be included as a Pre35% of cases where no previous trauma of the joint scribed Minimum Benefits (PMB) condition?
occurred. The reason for this is not completely under- As mentioned already the disease gets worse over time and
stood but doctors suspect that these medicines may eventually causes the bone to crumble or break (fracture).
interfere with the body’s ability to break down fatty substances. These substances accumulate in the blood Once the bone starts crumbling or a fracture occurs the
vessels, causing it to become narrow. The result is that condition is included in the PMB regulations.
the amount of blood flow to the bone is decreased.
• Excessive alcohol use causes fatty substances to build At this stage the condition is included in the PMBs under
up in the blood vessels, and decreases the blood sup- Closed fractures/ dislocations of limb bones
ply to the bones.
/epiphyses – excluding fingers and toes.
• Blood clots, inflammation, and damage to the arteries
- all these can limit or completely cut off blood supply What must be fully funded under PMB level of care?
to the bones.
Prescribed Minimum Benefits (PMB) specify that all diagno• Gaucher’s disease is an inherited metabolic disorder sis, treatment and care of the condition must be funded by
in which harmful amounts of a fatty substance accu- medical schemes. Medical schemes may opt to apply the
mulate in the organs, causing a restriction on the blood use of designated service providers (DSP), and managed
supply to the bones.
care protocols.
• Sickle cell disease – the disease causes the red blood
cells to become stiff and sticky. The cells are shaped Diagnostic tests
like sickles or curved moons instead of a round shape. The diagnostic tests that confirm the fracture of the bone
The irregular cell patterns can block the flow of blood must be funded as PMB level of care. These diagnostic
to the bone.
tests include radiology tests namely X-rays, and if need be
• Diabetes Mellitus Type I and II – the disease may cause a CT scan or MRI scan. It is important to remember that the
damage to the blood vessels, resulting in a restricted radiology tests will only be funded as PMB level of care if it
supply of blood to the bone.
confirms the fracture. If no fracture is confirmed the radiol• Pancreatitis (Inflammation of the pancreas – the dis- ogy test will be funded according to the scheme’s rules and
ease is associated with excessive use of alcohol and applicable limitations
may cause fatty substances to build in the blood vessels and decrease the blood supply to the bones.
Treatment of Avascular Necrotic Fractures
• HIV infection.
The only treatment for fractures includes surgical correc• Radiation therapy or chemotherapy – these treatments tion. Given the fact that in most cases the affected bone
may damage blood vessels.
crumbles and the joint collapses, the majority of surgical
• Decompression sickness – this occurs when the body interventions include a joint replacement. However suris exposed to a sudden reduction in the surrounding gical stabilisation with rods and screws etc. may also be
pressure. It causes the formation of gas bubbles in the performed. If the surgery is performed by a designated serblood, which can block blood flow to the bone.
vice provider (this include the hospital) the medical scheme
must fund the surgery in full.
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CMScript 9/2016
The internal prosthesis (rods and screws or an artificial
joint) must be funded in full by the medical scheme as long
as the same type of prosthesis that is available in the state
sector is used.
Care for Avascular Necrotic Fractures after surgery
Physical rehabilitation after a joint replacement or other
surgical correction is extremely important, and is included
in the PMB regulations in the form of physiotherapy. The
physiotherapy must be funded in full until the functional
progress has reached a plateau. The physiotherapist must
further train the affected person to continue with the exercises at home.
References:
Figure 1: http://keckmedicine.adam.com/graphics/images/
en/21730.jpg [Accessed 05 October 2016]
Avascular necrosis. http://www.mayoclinic.org/diseases-conditions/avascular-necrosis.htm [Accessed 05 October 2016]
Osteonecrosis. http://www.niams.nih.gov/Health_info/Osteonecrosis/default.asp [Accessed 05 October 2016]
Contact information:
[email protected]
Hotline: 0861 123 267
Fax: 012 430 7644
The clinical information furnished in this
article is intended for information purposes only and professional medical
advice must be sought in all instances
where you believe that you may be
suffering from a medical condition. The
Council for Medical Schemes is not liable for any prejudice in the event of any
person choosing to act or rely solely on
any information published in CMScript
without having sought the necessary
professional medical advice.
WHAT ARE PRESCRIBED
MINIMUM BENEFITS?
Prescribed Minimum Benefits (PMBs) are defined by law. They are the minimum level of
diagnosis,treatment, and care that your medical
scheme must cover – and it must pay for your
PMB condition/s from its risk pool and in full.
There are medical interventions available over
and above those prescribed for PMB conditions
but your scheme may choose not to pay for them.
A designated service provider (DSP) is a healthcare provider (e.g. doctor, pharmacist, hospital)
that is your medical scheme’s first choice when
you need treatment or care for a PMB condition.
You can use a non-DSP voluntarily or involuntarily but be aware that when you choose to use a
non-DSP, you may have to pay a portion of the
bill as a co-payment. PMBs include 270 serious
health conditions, any emergency condition, and
25 chronic diseases; they can be found on our
website
CMScript 9/2016
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