Avascular Necrosis of Bone and Lupus

[Guest guest]

Avascular Necrosis of Bone and Lupus

Marvin E. Steinberg, MD

Avascular necrosis of bone (AVN) is a disorder in which an avascular

(lacking in blood supply) area of bone undergoes necrosis (dies). AVN

is not common, but it is encountered in a certain number of patients

with lupus. The area most often affected is the hip and in particular

the upper part of the thigh bone (the femoral head) which makes up

the ball of this ball-and-socket joint. This problem primarily

affects younger adults. In 50 to 60 percent of cases it occurs in

both hips. The goal for treatment of AVN is to save the natural hip

joint if possible and not to have to replace the affected femoral

head with an artificial joint. In order to accomplish this, early

diagnosis is very important. Other bones may also be affected by AVN,

but much less often than the hip. (These include the knee, the

shoulder, and rarely the small bones of the wrist and the foot or

ankle.) The following discussion will, therefore, focus on the hip.

Causes

Many things can cause AVN. One of the most common causes is a

fracture through the thigh bone which results in tearing of the blood

vessels that nourish the femoral head. AVN can also occur without a

fracture or other major injury. These same blood vessels can be

blocked by blood clots (thrombi or emboli). They can also be blocked

by fat droplets which form in the circulating blood, by clumps of

abnormal red blood cells (as in sickle cell disease), and

occasionally by nitrogen bubbles (which form in individuals such as

deep sea divers who work under different atmospheric pressures). AVN

can also result from inflammation or narrowing of the arteries, and

from increased pressure outside the blood vessels. it is frequently

seen with excess use of alcohol. A very small percentage of people

who use corticosteroids for prolonged periods of time will also

develop it. Why this is so is unclear. It may be that certain

individuals are especially sensitive to steroids and form circulating

fat droplets as a result. Although some authorities are of the

opinion that the blood vessel changes in lupus itself can result in

AVN, there are almost no cases of AVN reported in patients with lupus

who have not been treated with steroids.

Within a few hours after the blood circulation to the bone is

blocked, the cells in the bone marrow and the bone begin to die. The

body then makes an attempt to repair the damage. During this repair

process the pressure within the bone begins to build. In

approximately 80 percent of cases, a steady progression of damage

takes place. The dead area of bone becomes weakened and begins to

collapse. This starts in the soft bone underneath the surface of the

joint. Eventually, however, the joint surface itself becomes

involved, and actual flattening of the normally round femoral head

results. The cartilage of the joint is subjected to abnormal stresses

and undergoes gradual degeneration (breakdown). Since this cartilage

gets its nourishment from the fluid within the joint and not from the

blood supply of the underlying bone, it remains alive for quite some

time after the initial degeneration begins. In the later stages,

cartilage damage ultimately leads to advanced degenerative arthritis

involving the entire hip joint.

Clinical Course

At first the patient with AVN has no symptoms. Later the buildup of

pressure within the femoral head may cause a mild and vague type of

pain. Once collapse of the joint surface occurs, the pain usually

increases dramatically and may become severe. Some patients however

have only mild discomfort in spite of significant involvement of the

joint. As the process continues, most patients develop a limp and

note some decrease in motion of the hip joint.

Early on, routine x-rays in AVN are entirely normal. As the softer

bone below the joint surface begins to collapse, a fluid filled space

is left which shows up as a dark semi-circle or " crescent sign " on

the x-ray. Later actual flattening of the normally round femoral head

may be seen. Thinning of the cartilage of the joint results in

narrowing of the joint space. This will show on an x-ray. Still later

the characteristic picture of advanced degenerative joint disease is

seen on the x-ray and may be accompanied by complete loss of the

joint space, the formation of spurs (or osteophytes), large cysts,

and areas of dense bone.

There are other special imaging techniques which are frequently used

to diagnose AVN in addition to plain x-rays. Often these techniques

show clear changes in the bone before such changes can be detected on

the routine x-ray. These include bone scans, computerized tomography

(CAT) scans, and magnetic resonance imaging (MRI). During the last

few years, MRI has proven to be the single best method for the early

diagnosis of AVN. The MRI does not use x-rays but uses magnetic waves

to show very early changes in the marrow of the bone, bone itself,

and other tissues in and around the hip joint. It is a very safe

technique and is both very sensitive and very specific for AVN.

Treatment

In 80 or 90 percent of cases of AVN, the condition will progress even

if we restrict activities and limit weight bearing on the joint by

having the patient use canes or crutches. For this reason, it is

usually best not to try to treat the hip " conservatively " if it is

important to save the joint. (The shoulder and knee do better

with " conservative management " than the hip does, and this is usually

the treatment of choice for these joints.)

Although there is no completely effective method for preventing early

AVN of the hip from progressing, there are a number of surgical

procedures which give better results than conservative medical

management. These should be very seriously considered during the

early stages of AVN, before there has been any collapse of the joint.

They include drilling small or large holes to relieve the pressure,

bone grafting, osteotomy (cutting across the bone to change its

position), and electrical stimulation. There have been some

encouraging reports about the use of electrical stimulation, but this

technique is still in a somewhat experimental stage. Another new

procedure which seems quite promising is the use of a bone graft

containing its own blood vessels which can be attached to the

arteries and veins in the region of the hip. Although none of these

surgical treatments gives consistent or completely satisfactory

results, progress is being made, and the use of one of these

techniques will usually give better results than non-operative

management, as mentioned earlier.

Once there has been definite flattening of the femoral head, these

early surgical interventions are seldom of much value. At this stage,

patients should be treated conservatively with measures designed to

decrease their pain and preserve function of the hip. Such measures

include restricted activities, use of a cane, and non-steroidal anti-

inflammatory drugs or mild pain relievers.

When pain and disability have progressed to the point that

conservative methods of treatment are no longer effective in

relieving symptoms, reconstructive surgery should be considered.

There are two commonly used procedures: The replacement of only the

upper end of the femur (the " ball " ) with an " endoprosthesis " and the

replacement of both the ball and the socket with a " total hip

replacement " . Of these two operations, the use of a total hip

replacement seems to give the most consistent and durable results. It

leads to complete or nearly complete relief of pain and relatively

normal function in 90 to 95 percent of patients. With modern

techniques and devices these artificial hips should continue to

function for at least ten to fifteen years in the majority of

patients. In the younger individual they will rarely last a lifetime,

but when they do wear out, they can be replaced.

Summary

AVN is a rather uncommon complication in patients with lupus and is

probably related to the need to use corticosteroids rather than to

the underlying disease itself. The area most frequently involved is

the hip and specifically the femoral head. Although the condition may

heal spontaneously (without any treatment) in 10 to 20 percent of

diagnosed cases, most of the time it will get worse without specific

treatment. The goal is therefore to diagnose this condition as early

as possible and to use any one of a number of surgical procedures

which may prevent or slow down its progression. Although the results

with the present surgical methods of treatment are not as good as we

would like, they are generally better than simply relying on

symptomatic treatment. We remain optimistic that some of the newer

methods will give better results. When the condition has become

fairly advanced, such preventative measures are of little value and

patients are treated symptomatically for as long as possible. When

sufficient pain and disability have developed, reconstructive surgery

is usually needed. Of the available measures, total hip replacement

gives the best results. This procedure can allow patients to resume a

relatively normal lifestyle with little pain or disability.

[Guest guest]

Thanks for this great info Deanna. It was very informative and

answers many questions for me. Although my necrotic bone lesion is in

my left upper arm and measues 8 1/2 cm's. It has recently been

causing me grief and much discomfort. I am currnrtly not on steroids,

we have found that they push me right into CHF, but I was on 80mg's a

day for a very long time and I take daily steroid eye drops for my

vision loss. I know that in combination with my antiphospholipid

syndrome probably is what caused it. I take coumadin 7.5mg daily

because of the xtra clotting factors in my blood. Again, your article

was quite helpful and I can now be better armed at my next Dr. vist.

Take Care and gentle hugs, Pam

> Avascular Necrosis of Bone and Lupus

> Marvin E. Steinberg, MD

>

> Avascular necrosis of bone (AVN) is a disorder in which an

avascular

> (lacking in blood supply) area of bone undergoes necrosis (dies).

AVN

> is not common, but it is encountered in a certain number of

patients

> with lupus. The area most often affected is the hip and in

particular

> the upper part of the thigh bone (the femoral head) which makes up

> the ball of this ball-and-socket joint. This problem primarily

> affects younger adults. In 50 to 60 percent of cases it occurs in

> both hips. The goal for treatment of AVN is to save the natural hip

> joint if possible and not to have to replace the affected femoral

> head with an artificial joint. In order to accomplish this, early

> diagnosis is very important. Other bones may also be affected by

AVN,

> but much less often than the hip. (These include the knee, the

> shoulder, and rarely the small bones of the wrist and the foot or

> ankle.) The following discussion will, therefore, focus on the hip.

>

> Causes

>

> Many things can cause AVN. One of the most common causes is a

> fracture through the thigh bone which results in tearing of the

blood

> vessels that nourish the femoral head. AVN can also occur without a

> fracture or other major injury. These same blood vessels can be

> blocked by blood clots (thrombi or emboli). They can also be

blocked

> by fat droplets which form in the circulating blood, by clumps of

> abnormal red blood cells (as in sickle cell disease), and

> occasionally by nitrogen bubbles (which form in individuals such as

> deep sea divers who work under different atmospheric pressures).

AVN

> can also result from inflammation or narrowing of the arteries, and

> from increased pressure outside the blood vessels. it is frequently

> seen with excess use of alcohol. A very small percentage of people

> who use corticosteroids for prolonged periods of time will also

> develop it. Why this is so is unclear. It may be that certain

> individuals are especially sensitive to steroids and form

circulating

> fat droplets as a result. Although some authorities are of the

> opinion that the blood vessel changes in lupus itself can result in

> AVN, there are almost no cases of AVN reported in patients with

lupus

> who have not been treated with steroids.

>

> Within a few hours after the blood circulation to the bone is

> blocked, the cells in the bone marrow and the bone begin to die.

The

> body then makes an attempt to repair the damage. During this repair

> process the pressure within the bone begins to build. In

> approximately 80 percent of cases, a steady progression of damage

> takes place. The dead area of bone becomes weakened and begins to

> collapse. This starts in the soft bone underneath the surface of

the

> joint. Eventually, however, the joint surface itself becomes

> involved, and actual flattening of the normally round femoral head

> results. The cartilage of the joint is subjected to abnormal

stresses

> and undergoes gradual degeneration (breakdown). Since this

cartilage

> gets its nourishment from the fluid within the joint and not from

the

> blood supply of the underlying bone, it remains alive for quite

some

> time after the initial degeneration begins. In the later stages,

> cartilage damage ultimately leads to advanced degenerative

arthritis

> involving the entire hip joint.

>

>

>

>

> Clinical Course

>

> At first the patient with AVN has no symptoms. Later the buildup of

> pressure within the femoral head may cause a mild and vague type of

> pain. Once collapse of the joint surface occurs, the pain usually

> increases dramatically and may become severe. Some patients however

> have only mild discomfort in spite of significant involvement of

the

> joint. As the process continues, most patients develop a limp and

> note some decrease in motion of the hip joint.

>

> Early on, routine x-rays in AVN are entirely normal. As the softer

> bone below the joint surface begins to collapse, a fluid filled

space

> is left which shows up as a dark semi-circle or " crescent sign " on

> the x-ray. Later actual flattening of the normally round femoral

head

> may be seen. Thinning of the cartilage of the joint results in

> narrowing of the joint space. This will show on an x-ray. Still

later

> the characteristic picture of advanced degenerative joint disease

is

> seen on the x-ray and may be accompanied by complete loss of the

> joint space, the formation of spurs (or osteophytes), large cysts,

> and areas of dense bone.

>

> There are other special imaging techniques which are frequently

used

> to diagnose AVN in addition to plain x-rays. Often these techniques

> show clear changes in the bone before such changes can be detected

on

> the routine x-ray. These include bone scans, computerized

tomography

> (CAT) scans, and magnetic resonance imaging (MRI). During the last

> few years, MRI has proven to be the single best method for the

early

> diagnosis of AVN. The MRI does not use x-rays but uses magnetic

waves

> to show very early changes in the marrow of the bone, bone itself,

> and other tissues in and around the hip joint. It is a very safe

> technique and is both very sensitive and very specific for AVN.

>

> Treatment

>

> In 80 or 90 percent of cases of AVN, the condition will progress

even

> if we restrict activities and limit weight bearing on the joint by

> having the patient use canes or crutches. For this reason, it is

> usually best not to try to treat the hip " conservatively " if it is

> important to save the joint. (The shoulder and knee do better

> with " conservative management " than the hip does, and this is

usually

> the treatment of choice for these joints.)

>

> Although there is no completely effective method for preventing

early

> AVN of the hip from progressing, there are a number of surgical

> procedures which give better results than conservative medical

> management. These should be very seriously considered during the

> early stages of AVN, before there has been any collapse of the

joint.

> They include drilling small or large holes to relieve the pressure,

> bone grafting, osteotomy (cutting across the bone to change its

> position), and electrical stimulation. There have been some

> encouraging reports about the use of electrical stimulation, but

this

> technique is still in a somewhat experimental stage. Another new

> procedure which seems quite promising is the use of a bone graft

> containing its own blood vessels which can be attached to the

> arteries and veins in the region of the hip. Although none of these

> surgical treatments gives consistent or completely satisfactory

> results, progress is being made, and the use of one of these

> techniques will usually give better results than non-operative

> management, as mentioned earlier.

>

> Once there has been definite flattening of the femoral head, these

> early surgical interventions are seldom of much value. At this

stage,

> patients should be treated conservatively with measures designed to

> decrease their pain and preserve function of the hip. Such measures

> include restricted activities, use of a cane, and non-steroidal

anti-

> inflammatory drugs or mild pain relievers.

>

> When pain and disability have progressed to the point that

> conservative methods of treatment are no longer effective in

> relieving symptoms, reconstructive surgery should be considered.

> There are two commonly used procedures: The replacement of only the

> upper end of the femur (the " ball " ) with an " endoprosthesis " and

the

> replacement of both the ball and the socket with a " total hip

> replacement " . Of these two operations, the use of a total hip

> replacement seems to give the most consistent and durable results.

It

> leads to complete or nearly complete relief of pain and relatively

> normal function in 90 to 95 percent of patients. With modern

> techniques and devices these artificial hips should continue to

> function for at least ten to fifteen years in the majority of

> patients. In the younger individual they will rarely last a

lifetime,

> but when they do wear out, they can be replaced.

>

>

>

>

> Summary

>

> AVN is a rather uncommon complication in patients with lupus and is

> probably related to the need to use corticosteroids rather than to

> the underlying disease itself. The area most frequently involved is

> the hip and specifically the femoral head. Although the condition

may

> heal spontaneously (without any treatment) in 10 to 20 percent of

> diagnosed cases, most of the time it will get worse without

specific

> treatment. The goal is therefore to diagnose this condition as

early

> as possible and to use any one of a number of surgical procedures

> which may prevent or slow down its progression. Although the

results

> with the present surgical methods of treatment are not as good as

we

> would like, they are generally better than simply relying on

> symptomatic treatment. We remain optimistic that some of the newer

> methods will give better results. When the condition has become

> fairly advanced, such preventative measures are of little value and

> patients are treated symptomatically for as long as possible. When

> sufficient pain and disability have developed, reconstructive

surgery

> is usually needed. Of the available measures, total hip replacement

> gives the best results. This procedure can allow patients to resume

a

> relatively normal lifestyle with little pain or disability.