Children are not yet fully developed and have their own unique physiological or pathological development; in addition, they cannot express their medical history and symptoms correctly, so there are certain difficulties in diagnosis. This article summarizes the characteristics of common diseases of the pediatric extremities in order to deepen the understanding of them; hopefully, it will help to judge and treat them correctly and reduce the rate of misdiagnosis or underdiagnosis.
They are summarized as follows.
I. Pediatric bone and joint infections:
Pediatric skin resistance is weak, prone to prickly rash, scabies swelling, etc., more dental diseases; upper respiratory tract disorders are also more frequent. Therefore, it increases the chance of blood infection, such as bacteremia or sepsis. Combined with the characteristics of pediatric bone development, the infection rate is significantly higher than that of adults.
1. Acute hematogenous osteomyelitis:
The epiphysis of pediatric bone has more vascular tortuosity and venous collaterals, so the blood flow is slow. When the blood is infected with bacteria, it is easy to stay in the epiphysis and can cause infection of bone and its appendages.
Pain characteristics.
Persistent local pain, refusal to touch and feel, pain-avoidance claudication in the early stage, gradually reduced activity of the affected limb or dare not move, and severe pain when moving passively. If the abscess penetrates the periosteum, the pain can be relieved significantly due to the reduction of pressure in the bone.
Clinical points.
(1) Presence of potential foci of infection, such as scabies, dental caries and upper respiratory tract infection.
(2) High fever and chills, vomiting or dehydration.
(3) Persistent localized severe pain in the affected limb with high skin temperature; deep pressure pain in the epiphysis.
(4) circumferential swelling of the soft tissues of the affected limb, but heavier on one side.
(5) Reactive swelling or fluid accumulation in the adjacent joint, but movable.
(6) Pathological fracture if the condition is severe.
Diagnosis.
History, signs + stratified puncture + smear and mycoplasty + radiograph or nuclear scan
2. Acute septic arthritis.
Prevalent in children 1-3 years old, with the hip joint being the most common, followed by the knee and elbow joints. Mainly hematogenous, infection of adjacent bone or direct contamination. Staphylococcus aureus is the most common.
Pain characteristics.
Rapid onset, complaints of significant pain in the joint area, painful limp or inability to bear weight; joint flexion, refusal to touch and press; slight movement of the joint, severe pain may occur.
Key clinical points.
(1) History of underlying foci of infection or trauma.
(2) Toxic reactions such as high fever (T 40 0C).
(3) Swollen joints, high skin temperature, and obvious tenderness.
(4) Significant joint dysfunction with severe passive pain.
(5) semi-flexion of the joint (muscle contracture).
Diagnosis.
Systemic symptoms + physical signs + puncture, smear, mycoplasty + blood picture.
3.Bone and joint tuberculosis :
Pain characteristics.
The early stage of bone joint is intermittent, fixed joint swelling and pain (except hip pain can be radiated inside the knee), the pain is mild; very few acute onset, severe pain, more so at night. In the late stage, the pain is more severe and accompanied by joint deformity; special sleeping position or walking posture, forcibly changing and causing joint pain.
Clinical points.
(1) Prevalent in young children, mostly seen in frail, sickly, malnourished individuals.
(2) May not have received BCG vaccination.
(3) Bone or joint is secondary to infection, with the primary focus mostly in the lungs (95%).
(4) Chronic course with toxic symptoms such as low fever or afternoon hot flashes, night sweats, etc.
(5) Cold flow abscess formation.
(6) Advanced bone and joint dysfunction, stiffness and muscle atrophy, etc.
Diagnosis.
Clinical + puncture smear, mycoplasty, PCR + arthroscopy + X-ray or MRI examination. Early diagnosis is more difficult. If the bone and joint pain is more than two weeks and cannot be explained by inflammation, X-rays are required.
B. Bone tumors and tumor-like lesions
1.Bone like osteoma:
It is a benign tumor. It is found at the age of 5 to 25 years old, and mostly occurs in the femur and tibia.
Pain characteristics.
Pain alone is the main reason for consultation. The pain is mild and intermittent in the early stage, but gradually increases with the development of the disease and can be persistent; it is obvious at night and effective with oral aspirin and other analgesics. The pressure point is mostly on the side of the backbone.
Clinical points.
(1) The lesion mostly occurs in the cortex of the backbone.
(2) No redness or swelling at the site of pain.
(3) It may be accompanied by claudication, but the joint is usually not involved.
(4) Radiographs show that the lesion is often located in the cortical bone of the long bone, subperiosteal or near the medullary cavity, with neoplastic changes.
Diagnostic points.
Clinical + X-ray + CT
2.Bone cyst:
A tumor-like lesion that occurs within the bone in a confined and destructive manner. Commonly seen in children as young as 10 years old, the cause is unknown, and some believe it is due to absorption of intramedullary hematoma after trauma.
Pain characteristics.
No significant pain or only mild pain; severe pain may occur in case of fracture.
Clinical points.
(1) May be asymptomatic.
(2) Or only soreness and discomfort in the skeletal area.
(3) Occasionally found on radiographs.
(4) Pathologic fractures may occur with minor trauma and be detected on radiographs.
Diagnosis.
X-ray examination + differential
3. Osteosarcoma.
It is the most common malignant tumor in children, with a predilection for 10-20 years old, most common at 15 years old. It is twice more common in males than females. 50% occur in the lower femur and 20% in the upper tibia.
Pain characteristics: Pain is the earliest symptom, which is intermittent and vague at the beginning, and then turns into persistent and severe pain, which intensifies after activity or at night. Pain-avoidance claudication may occur in the affected limb.
Clinical points.
(1) The presence of a mass in the adjacent joint, which grows rapidly.
(2) Significant pain, worse at night.
(3) Slightly elevated skin temperature and surface venous anger.
(4) claudication with gradual restriction of joint function, but with some range of passive joint motion.
(5) distant metastatic lesions may be found.
Diagnosis.
Clinical + radiograph, CT or MRI + biopsy
4.Ewing’s tumor:
It occupies the second place among malignant tumors in children, mostly seen in 10-15 years old, more males than females by 2 times, preferably in femur, tibia, humerus, etc.
Pain characteristics.
Pain is a common complaint, often presenting as intermittent mild pain in the early stage, rapidly developing into persistent severe pain, with local masses appearing as the pain increases, with inflammatory manifestations of redness, swelling, heat and pain. Local pressure pain is obvious.
Key clinical points.
(1) Rapid onset and significant pain, worse at night.
(2) accompanied by fever (37.5-38.5 0C), malaise, anemia and loss of appetite.
(3) elevated leukocytes (up to 10-30×109/L), increased sedimentation, and positive Ben-Zhou test.
(4) Local swelling, high skin temperature, and significant pressure pain.
(5) Unique periosteal onion skin-like hyperplasia on radiographs.
(6) Similar to osteomyelitis-like manifestations, which need to be differentiated.
Diagnostic points.
Clinical + X-ray CT + biopsy
Three, chronic injury
1.Tendonitis:
Aseptic inflammation of the tendon sheath. Mostly occurs in the thumb, followed by the second and third fingers. Also known as popping finger or popping thumb. In children most are congenital.
Painful features.
Flexion of the finger is accompanied by light pain and light pressure pain in the metacarpophalangeal joint.
Clinical points.
(1) The affected finger is difficult to straighten after flexion.
(2) The popping or discomfort may occur with forceful flexion.
(3) bulging at the metacarpophalangeal joint with pressure pain.
Diagnosis.
Medical history + physical signs
2.Tendon sheath cysts and slapping fossa cysts:
Tendon sheath cysts usually occur at the dorsal wrist or ankle, and slap fossa cysts are mostly at the medial head of the gastrocnemius muscle; both have jelly-like fluid contents.
Painful features.
Localized cystic masses may become distended or uncomfortable with joint motion, but the pain does not interfere with joint motion.
Key clinical points.
(1) Incidental finding of a mass at the joint.
(2) Most children have a history of repetitive joint motion.
(3) The mass is semicircular and cystic in nature, and the pain is usually not obvious.
(4) The mass gradually increases in size without local inflammatory manifestations.
(5) The mass has clear borders and is not mobile.
Diagnosis.
History+signs+B ultrasound
3.Injectable gluteal contracture:
It is a chronic medical injury, mostly seen in children who are frail and sickly and have a history of repeated intramuscular injections; such as penicillin potassium salt or painless water with this methanol. It usually involves both buttocks.
Pain characteristics.
No obvious pain or discomfort in upright position; distension or discomfort in the buttocks may occur in squatting position; discomfort or pain in the buttocks increases as squatting activity increases.
Clinical points.
(1) History of repeated gluteal muscle injections.
(2) Gait is externally rotated and abducted, i.e., “figure of eight” gait.
(3) The knees together cannot squat, but the knees apart is sufficient, i.e. the so-called “circling sign”.
(4) pointed hips, the buttocks can be seen in the sulcus-like subsidence.
(5) When the hip is flexed laterally and then internally rotated and then straightened, the hip can be heard as a popping sound.
(6) Stiff bands can be palpated on the hip.
Diagnosis.
Medical history + physical signs
Osteochondritis
The disease is more common in pediatric patients, especially in the lower limb pain accounts for a larger proportion.
1. osteochondritis of the femoral head:
Also known as aseptic necrosis of the femoral head, ischemic necrosis of the femoral head, and flat hip. Most commonly seen in 4-8 years old, male:female about 4:1. 10% are bilateral, girls have a poorer prognosis. The pathology is divided into four stages; namely, synovial inflammatory stage (about 1 week), ischemic necrosis stage (months or years), fragmentation or recovery stage (2-3 years), and healing or terminal stage.
Pain characteristics.
In the early stage (stage I-II), chronic pain with abnormal gait or intermittent claudication occurs. Children often complain of discomfort or strain in the hip or thigh, and the pain may radiate to the knee or medial thigh. The pain may radiate to the knee or inner thigh. When the pain is obvious, there may be difficulty in squatting and contracture of the adductor and iliopsoas muscles. In the late stage (III-IV), the pain may be significantly reduced or painless limping may occur, and the hip function is basically normal.
Clinical points.
(1) Unexplained claudication with difficulty in squatting.
(2) Complaints of medial knee pain without localized pressure pain.
(3) pressure pain in the center of the affected hip, internal or external rotation of the hip may induce pain, or partial restriction of movement.
(4) Late stage children have reduced pain or no symptoms, with muscle atrophy of the affected limb or shortening of the lower limb, and mildly restricted or normal hip joint activities.
Diagnostic points.
X-ray film + nuclear scan + CT or MRI
2, tibial tubercle osteochondritis:
Most commonly seen in 8-15 years old, more males than females, unilateral. Associated with quadriceps muscle pulling.
Pain characteristics.
Restricted pain at the tibial tuberosity after exercise, localized swelling, may have pressure pain or percussion pain. The pain can be induced by squatting or going up or down stairs. The pain is relieved or disappears after a few days of rest.
Clinical points.
(1) The affected child likes strenuous sports, such as kicking a ball.
(2) Generally faster growth and development, older than the actual age order.
(3) The tibial tuberosity is elevated and swollen and painful, more pronounced after exercise.
(4) The mass gradually increases in size with continued sports.
(5) In severe cases, there is atrophy of the quadriceps muscle, weakness and claudication.
(6) pressure pain and percussion pain of the tibial tuberosity.
Diagnosis.
History + physical signs + radiographs
V. Unnamed causes of pain in the lower limbs
1. Growing pains.
The cause is unknown and may be related to excessive growth, overexertion, weather changes or micronutrient deficiency.
Pain characteristics.
Pain often appears above and below the knee joint, soreness or tingling, mostly occurs in the evening or before bedtime, the pain lasts more than a few minutes, and
The pain lasts for a few minutes and rarely lasts more than an hour. The pain has no obvious fixed location and is not accompanied by redness, swelling, heat, or pain, and may disappear quickly with heat or light massage.
Clinical points.
(1) Irregular, intermittent, sudden onset limb pain.
(2) Often present in the upper or lower knee joint or lower leg.
(3) The pain is short-lived, lasting from a few minutes to a few hours.
(4) Occurs mostly in the afternoon or at bedtime.
(5) No local inflammatory manifestations and no positive signs on examination.
(6) Everything returns to normal after the pain has passed.
(7) The child often likes to run and jump and has a poor or picky diet such as little vegetables.
Diagnosis.
History+signs+identification
2. Transient hip synovitis.
Also called acute temporary synovitis of the hip joint. The cause is unknown, there may be a history of minor injuries, upper respiratory tract infection, etc. Most often seen 5 to 10 years old, common around 5 years old, unilateral joint is common, more males than females.
Pain characteristics.
Acute hip pain or radiation to the inner thigh and knee, painful claudication, mild limitation of hip function. Pain may disappear in a few hours or days.
Key clinical points.
(1) Acute onset, most with no apparent cause or a history of mild trauma or episodes of upper sensation.
(2) Limp with pain in the medial knee or hip joint.
(3) Pain lasting several hours or days, with a “transient” disappearance.
(4) Pain or mild restriction of movement can be induced by internal and external rotation or abduction of the hip joint, but normal flexion and extension.
(5) Good prognosis.
Diagnosis.
History+signs+diagnosis
Sixth, connective tissue diseases
1, rheumatic fever.
It is a common recurrent acute or chronic systemic inflammation of collagenous tissues, with cardiac and off involvement, and its active phase is called rheumatic fever. The disease occurs in 5-15 years old. It is more common in the north. It mainly invades the knee joint, followed by the ankle joint.
Pain characteristics.
(1) Recent (1-4W) history of upper respiratory tract infection, etc., especially hemolytic streptococcus.
(2) With fever or cardiac etc. involvement.
(3) Wandering arthralgia, which may manifest as redness, swelling, heat, pain, and pressure.
(4) May be accompanied by subcutaneous nodules or erythema of the limbs, chorea, etc.
(5) The disease may be followed by heart and other disorders, but not joint deformities.
Diagnosis.
Clinical + laboratory tests (BT, ESR, ASO, CRP, IGM, IGG) + electrocardiogram + differential
2. Rheumatoid arthritis.
It is a systemic connective tissue disease, mainly manifesting as a systemic autoimmune disease, characterized by chronic synovitis. The average age of onset is 6 years, more women than men.
Pain characteristics.
Joint pain is predominant, with joint swelling, effusion, mildly elevated skin temperature, and functional limitations. In advanced stages, there may be persistent joint pain, joint deformity, and functional impairment.
Clinical points.
(1) The affected joints are mostly found in the wrist, knee and finger (toe) joints, mostly wandering or symmetrical.
(2) In children, the disease is characterized by emaciation, anemia, and low appetite.
(3) Recent cold, cold, dampness, etc. may be present.
(4) Multi-joint onset, joint swelling, pain, stiffness or morning stiffness.
(5) Long history of disease, usually with sequelae.
(6) May be accompanied by significant liver and spleen, rash and eye inflammation.
(7) X-rays may show joint space narrowing, bone surface cystic changes and osteoporosis.
(8) STILL disease is accompanied by fever (37-41oC) and chills in addition to joint symptoms.
Diagnosis.
Clinical + laboratory tests (BT, RF, ESR, ASO, CRP, HLA-B27) + radiographs
VII. Traumatic fracture and dislocation
Pain characteristics.
Severe pain, painful self-defense muscle contracture and dysfunction, which can be aggravated by touching the local or percussion on the distal end.
Clinical points.
(1) A history of trauma.
(2) Localized swelling and pressure pain.
(3) deformity or elastic fixation with anatomic site derangement.
(4) fracture sounds or bone rubbing sensation.
(5) Functional impairment with significant passive pain.
(6) longitudinal percussion pain or severe pain at the injured site caused by moving the distal segment of the bone.
Diagnosis.
History + clinical + X-ray or CT