bubble_chart Overview

Acute suppurative arthritis is an acute inflammation of the joints caused by pyogenic bacteria. Hematogenous cases are more common in children, often affecting a single large limb joint such as the hip, knee, or elbow. In cases of firearm injuries, the affected joint depends on the injury site, with the knee and elbow joints generally having a higher incidence.

bubble_chart Etiology

Disease cause

Acute suppurative arthritis is most commonly caused by staphylococci, followed by streptococci. Gonococci and pneumococci are rare. Bacteria can invade the joint through hematogenous spread, traumatic injury, or extension from adjacent infected lesions. Hematogenous infection may also be a complication of acute fever, such as measles, scarlet fever, or pneumonia, and is more common in children. Traumatic cases are often due to open injuries, especially when the wound is not properly treated. Adjacent infections, such as acute suppurative osteomyelitis, can directly spread to the joint.

Pathogenesis

After bacteria invade the joint, synovitis occurs first, leading to joint effusion, swelling, and pain. As the condition progresses, the effusion changes from serous to serofibrinous and eventually becomes purulent. When the joint is affected, the lesion gradually invades the cartilage and bone, eventually resulting in joint stiffness. After the joint becomes suppurative, it may rupture the joint capsule and skin, forming a sinus, or spread to adjacent tissues.

bubble_chart Diagnosis

In the acute phase of suppurative arthritis, the main symptoms are manifestations of toxicity. The patient suddenly experiences shivering and high fever, with severe systemic symptoms. In pediatric patients, high fever may induce spasms. Locally, there are acute inflammatory manifestations such as redness, swelling, pain, and marked tenderness. Joint fluid increases, leading to fluctuation, which is more pronounced in superficial joints like the knee, presenting with a floating patella sign. Patients often keep the knee joint in a semi-flexed position to relax the joint capsule and reduce tension. Prolonged flexion can result in joint flexion contracture, with pain upon slight movement and protective muscular rigidity. If treated appropriately in the early stages, systemic and local symptoms gradually subside. If the joint surface remains undamaged, full or partial joint function can be restored.

Diagnosis is primarily based on medical history, clinical symptoms, and signs. For patients suspected of hematogenous suppurative arthritis, blood and joint fluid bacterial cultures and drug sensitivity tests should be performed. X-ray examinations are of limited help in the early stages, showing only joint swelling. Later, bone decalcification may be observed, with joint space narrowing due to cartilage and bone destruction. In the advanced stage, bony or fibrous ankylosis and deformities may occur, along with new bone proliferation, though sequestrum formation is rare.

Acute suppurative arthritis should be differentiated from acute suppurative osteomyelitis, wind-dampness arthritis, subcutaneous nodular arthritis, and rheumatoid arthritis.

bubble_chart Treatment Measures

The principle of treatment is early diagnosis and timely, proper management to preserve life and limbs, and to maintain joint function as much as possible.

Systemic treatment is the same as for acute suppurative osteomyelitis. In the case of firearm injuries, initial stage [first stage] surgical management should be performed to prevent joint infection.

Local treatment includes joint aspiration, immobilization of the affected limb, and surgical incision and drainage. For closed cases, joint fluid should be aspirated as much as possible. If the fluid is exudative or turbid, it should be rinsed with warm saline until clear, followed by antibiotic injection, performed once daily. If pus or post-traumatic infection is present, early incision and drainage should be performed, with the synovial membrane sutured to the skin edge. No drainage material should be left in the joint cavity. The wound can also be treated with antibiotic drip drainage or local wet compresses to control the infection as quickly as possible.

The affected limb should be appropriately immobilized or placed in traction to alleviate pain, prevent the spread of infection, maintain functional positioning, and avoid contracture deformities or correct existing ones. Once acute inflammation subsides or the wound heals, active and grade I passive joint exercises should be initiated to restore joint mobility. However, exercises should not be started too early or excessively to prevent symptom recurrence.

In summary, with timely treatment, outcomes are favorable, especially in children, where joint function can be restored.