Osteochondritis of the elbow

(Osteochondritis dissecans -

OCD)

Osteochondritis is a relatively rare condition of the elbow where cracks form in the cartilage and

subchondral bone (bone just under the cartilage that supports the cartilage).

 Small fragments of bone and cartilage may flake off and float into the joint, forming loose bodies

(see loose bodies).

 The softened cartilage and subchondral bone leads to pain and swelling of the joint.

 Osteochondritis is not particular to the elbow, it can happen in any joint, some joints and parts of joints are more prone to it.

 In the elbow it usually affects the lateral part (outside of the elbow) on the humerus (upper arm bone).

 This small area is called the capitellum.

Osteochondritis dissecans of the elbow is more common in adolescents who undertake sporting activities that place increased stress on the

outer side of the elbow. Medically this is termed a valgus stress.

 Sports that place an increased valgus stress on the elbow include gymnastics, overhead pitching sports (classically baseball).

 In the USA osteochondritis of the elbow is often referred to as "Little leaguers" elbow.

 It is not the sport per se but the repeated abnormal increased stress on the outside of the immature elbow joint.

 As such any sport or activity that overloads the lateral aspect of the joint may lead to osteochondritis.

Cause of osteochondritis

Some people are more prone to OCD, OCD does run in some families and does have a genetic link.

 It does not however follow that if you have had OCD that your children or family members will necessarily get it.

 It is multifactorial and also related to the stresses you place on your elbow.

Another possible cause is the small blood vessels that supply the nutrients to that part of the elbow may become blocked leading damage

to the bone and joint (avascular necrosis).

These causes are a part of the process, a major role is the overuse and persistent valgus stress eg.  a little league baseball pitcher who

trains and throws too much.

Overhead throwing repeatedly, places considerable stress on the outside of the elbow (radiocapitellar joint).

Racket sports and hitting a ball, baseball or tennis also places considerable stress on the outside of the elbow.

Gymnasts place considerable stress when taking their body weight on their arms with elbows locked out straight.

Repeated injury leads to softening of the cartilage, cracks may then form in the cartilage and extend into the subchondral bone.

 With continued stress on the damaged cartilage and bone part of the bone may undergo avascular necrosis.

 Occasionally the sbchondral bone and small pieces of cartilage may flake off.

 This creates a loose body that may cause locking.

 The area of the joint that it flakes off is then left bare of cartilage and this rough bare area may also lead to episodes of locking, clicking and

crunching.

 The elbow may feel like it is giving way when it is loaded.

  OCD Vs Panners disease

A different kind of avascular necrosis affects the capitellum (Panners disease), this is slightly different from OCD of the elbow in terms of

recovery and prognosis.

Panners disease occurs predominantly in boys between the age of 5 -10.

 For some reason the blood supply to the whole capitellum growth centre becomes interrupted.

It has a better prognosis to OCD in an adolescent and normally heals completely when growth is completed.

OCD occurs in adolescents age 12-15

 after growth in the capitellum has stopped.  Elbow OCD affects only a part of the capitellum usually the inside lower edge.

The prognosis and outcome following elbow OCD is not as good as for Panners disease.

In reality Panners and OCD of the elbow may represent a spectrum of the same problem.

Symptoms

Elbow OCD may not always follow a discrete injury, but may develop insidiously over time beginning with an ache after sporting activity that

resolves quickly with rest.

With continued use the pain may progress to a deep seated vague pain that lingers after using the arm.

The elbow may feel stiff and may not fully straighten.

If the cartilage flakes off or a loose body forms the elbow may catch, lock, click and grind.

If allowed to progress and if it does not heal well patients may go on to early arthritis of the joint.

Diagnosis

The diagnosis is made on the history of age young child or adolescent, symptoms as above, pain usually more on the outside, but may be a

vague deep seated pain.

The pain is made worse with activity and better with rest.

Symptoms are commonly worse at night.

Children and adolescents do not get tennis elbow, if your child has been diagnosed as having tennis elbow, re think the diagnosis and see a

specialist.

X rays may be normal or nearly normal early on, or when only a small area is involved.

 In advanced or severe cases it will show the bone changes in the subchondral bone and if a loose body has formed it may be visible.

(Beware loose bodies are not always evident on plain x rays).

 If the diagnosis is not clear then an MRI scan will be requested.

It is often a lot more obvious on the MRI scan.

The stage of the disease is also better characterized on an MRI.

Treatment

Treatment depends on the stage of the disease and the severity of symptoms. It is usually non operative in the first instance.

Non operative treatment

Relative rest - doing nothing is just as bad as doing too much.

Rest the joint but keep it gently moving so it does not stiffen up.

The remaining cartilage, muscles, ligaments and bones are nourished by movement.

Rest for 3-6 weeks followed by gradual increase in activity over 3-6 months.

Activity modification - Avoid those activities that upset the joint.

For sportsmen and women pay attention to sporting technique, avoiding where possible a valgus stress on the elbow.

"Listening" to the elbow, "If it hurts you are doing too much, if it doesn't you can do more".

Adjust training schedules to allow the elbow to recover between sessions.

Analgesics - Pain killers may help with the symptoms of pain particularly the NSAID's (see pain killers).

BEWARE this is one condition where you don't want to mask the pain and it is better to undertake relative rest and activity modification than

to take pain killers.

A physiotherapist may help advise on sport specific modifications and on a training program to maintain range of motion and strengthen

the muscles around the elbow. eg baseball pitchers and racket-sport players might benefit from keeping the elbow straight, instead of

angled outward, during the acceleration phase of the pitch or swing.

Mostly it is time and mother nature allowing the OCD lesion to heal, time for the cartilage and subchondral bone to revascularize and

mature.

Operative treatment

If non operative treatment fails surgery may help.

Depending once again on the stage of the disease and the problematic symptoms several options are available.

•

Elbow arthroscopy - It is possible arthroscopically, with key hole surgery to have a look at the cartilage, debride any rough edges and

if loose bodies are present, remove them. If the cartilage has flaked off leaving a raw patch of bone the base is freshened up and the

subchondral bone drilled or microfractured. This stimulates a healing response to heal the cartilage, the cartilage heals with

fibrocartilage, not as good as articular cartilage but better than raw bone.

•

Re attachment - If a large piece of subchondral bone and cartilage detaches it is sometimes possible to freshen the bed and re attach

it. This may be done arthroscopically or open depending on the size and site.

•

Cartilage replacement (mosaicplasty) (Osteochondral autografting (OATS)) If the fibrocartilage created by the body following

microfracture is not durable enough and or if the area of cartilage loss is so large that pain, stiffness and locking persists. Then it is

possible to transplant cartilage from another joint into the elbow. There is an element of "robbing peter to pay Paul" in that the

surgery does involve removing plugs of normal cartilage and subchondral bone from one joint (normally the knee) and transferring it

to the elbow.

NOTE: in Panners disease surgery is rarely required symptoms and signs often resolve with non operative intervention, it may take a

number of months but will resolve.

References

Lateral compression injuries in the paediatric elbow: Panner's disease and osteochondritis dissecans of the capitellum.; Kobayashi K, Burton

KJ, Rodner C, Smith B, Caputo AE; J Am Acad Orthop Surg. 2004 Jul-Aug;12(4):246-54.