The common cold is an accumulation of fluid in the hip joint. It affects the ability to walk and is the most common cause of lameness in children between the ages of three and ten. The management of a common cold will usually heal after a few days.

Definition of hip cold

The common cold corresponds more exactly to an acute transient synovitis of the hip. A synovitis is an inflammation of the synovial membrane, a membrane located at the joints that secretes the synovia. While this viscous fluid normally facilitates movement in the joints and limits friction between the bones, synovia can build up in the hip area and affect the ability to walk. This is precisely what happens with a hip cold, or acute transient hip synovitis. The inflammation is said to be acute and transient, which means that it occurs suddenly but disappears after a certain time.

Causes of the common cold

If the common cold is characterized by an accumulation of fluid in the hip joint, this intra-articular effusion has an unknown origin to date. However, a viral infectious etiology is suspected. It is clear that there is often a viral infectious episode in the ENT sphere or the digestive tract before the appearance of acute transient synovitis. Another explanation is sometimes put forward: a micro-traumatic origin. Further studies are expected to learn more about the cause (s) of the common cold.

Diagnosis of the common cold

The diagnosis usually involves:

• a clinical examination by a healthcare professional;
• an x-ray of the pelvis, a medical imaging test that may show capsular swelling characteristic of joint effusion associated with the common cold.

X-rays can also be used to rule out other problems such as osteochondritis, an abnormality in the growth of bone and cartilage. The healthcare professional’s diagnosis can also be confirmed by other additional examinations such as ultrasound, blood count and measurement of C-reactive protein.

People affected by the common cold

Acute transient hip synovitis is primarily diagnosed in children between the ages of three and ten. When the common cold is diagnosed in adults or adolescents, it is often a sign of an abnormality in the joints. A more complete diagnosis is needed.

The common cold in children affects boys more often than girls. 2 out of 1000 children are affected each year and in 70% of cases, they are boys. It also seems that the common cold is best seen in winter and spring.

Severe pain

The common cold results in sudden pain in the hip that projects to the thigh and knee. The intensity of the pain is such that it limits movement.

Difficulty walking

The common cold causes functional impotence of the lower limb, that is, a total or partial loss of function of the lower limb. Acute transient hip synovitis is the most common cause of lameness in children between the ages of three and ten.

Other associated symptoms

In some cases, the common cold is accompanied by a moderate rise in temperature (below 38,5 ° C). In addition, this pathology is often preceded by a viral infectious episode affecting the ENT sphere or the digestive tract. Symptoms specific to these infections can be seen.

Treatment of the common cold is generally based on:

• a period of rest in order to limit as much as possible the mobilization of the hip joint;
• the prescription of analgesics to fight against pain.

If the joint is very stiff and / or if the pain is too great, a hip traction can be used in children. This treatment relieves pain and generally allows healing after a week.

Four to six weeks after healing, an X-ray workup may be recommended to verify the absence of osteochondritis of the femoral head. Femoral bone growth anomaly, the latter is the second most common hip condition in children between the ages of four and ten.

Since the causes of the common cold are still poorly understood to date, no means of prevention have really been identified. Regular medical monitoring of the child remains the best solution to diagnose any abnormalities in the joints or bones as early as possible.