| disease | Chronic Osteomyelitis |
Chronic suppurative osteomyelitis is a continuation of acute suppurative osteomyelitis. Most systemic symptoms usually disappear, and systemic manifestations only occur when local drainage is obstructed. Generally, symptoms are limited to the local area and are often stubborn and difficult to treat, sometimes persisting for years or even decades without complete recovery. Currently, with proper planned treatment, most cases can be cured within a short period.
bubble_chart Etiology
During the acute phase, with timely and aggressive treatment, most cases can be cured, but many patients still develop chronic osteomyelitis. Common causes of chronic osteomyelitis include the following:
(1) Failure to receive prompt and appropriate treatment during the acute phase, leading to the formation of a large amount of dead bone.
(2) The presence of dead bone, foreign bodies such as shrapnel, and dead spaces.
(3) Extensive local scar tissue and sinus formation, poor circulation, which favors bacterial growth, and the inability of antibiotics to reach the affected area.
After the acute symptoms disappear, the general condition improves, but the lesions persist, transitioning into the chronic phase.
Due to the formation of sequestra, larger sequestra cannot be absorbed and become foreign bodies and bacterial foci, causing surrounding inflammatory reactions and new bone proliferation, forming an involucrum, thus resulting in thickened and rough bone. If a sinus forms, it often does not heal for years. If drainage is poor, systemic symptoms may occur.
If the bacterial virulence is low or the body's resistance is strong, the abscess may be confined within the bone, presenting as a localized intraosseous abscess, known as Brodie's abscess. It commonly occurs at the upper or lower ends of the tibia, with no obvious symptoms initially, and only manifests as local redness, swelling, and pain during the first episode months or years later. If the affected bone undergoes extensive proliferation, obliterating the medullary cavity and impairing circulation, it leads to sclerosing diffuse osteomyelitis, known as Garre's sclerosing osteomyelitis. This most frequently occurs in the femur and tibia, primarily presenting as intermittent pain.
Clinically, when entering the chronic inflammatory phase, there is localized swelling, thickened bone, a rough surface, and tenderness. If a sinus is present, the wound does not heal for a long time, and occasionally small pieces of sequestrum are discharged. Sometimes the wound temporarily heals, but due to the presence of an infected lesion, the inflammation spreads, leading to acute episodes with systemic chills and fever, as well as localized redness and swelling. After incision and drainage, spontaneous rupture, or medication control, the systemic symptoms disappear, the local inflammation gradually subsides, and the wound heals. However, such episodes recur repeatedly. When overall health is poor, it is also prone to trigger episodes.
Due to recurrent inflammation and multiple sinuses, limb function is significantly affected, with muscle atrophy. If a pathological fracture occurs, limb shortening or angular deformity may result. If the condition is close to a joint, joint contracture or stiffness often occurs.
X-ray images can reveal sequestra and a large amount of dense new bone formation, sometimes with cavities. In cases of war injuries, shrapnel may be present. Brodie's abscess on X-ray shows a round radiolucent area in the metaphysis of a long bone, with dense bone surrounding the abscess. In Garre's osteomyelitis, the bone is generally coarser and denser, with no obvious sequestrum and disappearance of the medullary cavity.
The diagnosis of chronic osteomyelitis is based on a history of acute osteomyelitis or open fracture, examination of the local lesion, and X-ray findings, making it relatively straightforward. However, it still needs to be differentiated from the following conditions.
(2) Osteoid bone tumor: Often misdiagnosed as a localized abscess, but its characteristics include constant dull pain, worse at night, significant local tenderness but no redness or swelling, and rare systemic symptoms. X-rays can further aid in differentiation.
(3) Diaphyseal fleshy tumor: Local and X-ray findings may occasionally be confused with osteomyelitis, but differentiation can be made based on the site of occurrence, age, clinical manifestations, and X-ray features.
bubble_chart Treatment Measures
The treatment of chronic suppurative osteomyelitis generally adopts a comprehensive approach combining surgery and medication, aimed at improving the patient's overall condition, controlling infection, and performing surgical interventions. Due to prolonged bed rest caused by severe illness, especially after hematogenous acute episodes, it is crucial to enhance the patient's systemic condition. In addition to using antibiotics to control infection, measures such as improving nutrition, blood transfusion when necessary, surgical drainage, and other treatments should be implemented.
The choice of medication should be based on bacterial culture and drug sensitivity tests, employing effective antibiotics.
In cases of acute recurrence, treatment should first follow the protocol for acute osteomyelitis, including enhanced supportive therapy and antibiotic use. Incision and drainage may be performed if necessary to control acute inflammation.
If sequestra, sinus tracts, cavities, or foreign bodies are present, surgical intervention is required in addition to drug therapy. Surgery should be performed when the systemic and local conditions improve, sequestra are separated, a sufficient involucrum has formed, and new bone can support limb weight. The principle of surgery is to thoroughly remove the lesion, including sequestra, foreign bodies, sinus tracts, infected granulation tissue, and scar tissue, followed by appropriate drainage to achieve complete cure. Osteomyelitis surgery often involves significant bleeding, so it should ideally be performed under hemostatic conditions, with preparations for blood transfusion.
(1) Open drainage after lesion clearance: In the past, the Orr open surgery method was commonly used to remove lesions, eliminate dead space, and ensure adequate drainage for healing. This involves complete removal of sinus tracts, scar tissue, sequestra, and foreign bodies, as well as debridement of granulation tissue in the dead space and resection of unhealthy bone and cavity edges to create a saucerized shape. However, excessive bone removal should be avoided to prevent fractures, and minimal dissection of surrounding soft tissues (e.g., periosteum) is advised to avoid further impairing circulation and hindering healing. The wound is left open and packed with gauze, followed by external plaster fixation. Dressings are changed every 2 weeks initially, then every 4–6 weeks until healing. This method has drawbacks, such as prolonged wound healing requiring frequent plaster changes, strong odor, prolonged joint stiffness due to immobilization, muscle atrophy, and significant scarring. It remains useful for a small subset of patients with large soft tissue defects or non-closable skin wounds.
(2) Lesion clearance with drip irrigation drainage: Since 1956, our hospital has adopted an improved method. After thorough lesion clearance and saucerization of the dead space, the wound is washed, and only the skin is sutured at specific points without layered closure. Two thin catheters or plastic tubes are placed in the wound. Postoperatively, one tube is used for drip irrigation drainage with saline (Figure 3-198), containing 800,000 units of penicillin per 1000 mL of saline, administered at about 2000 mL daily, while the other tube serves for negative-pressure suction. When the patient's temperature normalizes for about a week, the infection is easily controlled due to adequate irrigation and drainage, allowing the bone cavity to organize and ossify. Most wounds heal within a month. Recurrence or non-healing in a few cases is often due to incomplete lesion clearance, which can be resolved with repeat surgery and thorough drainage. Postoperative sutures should not be too tight to ensure continuous inflow and outflow of fluid and avoid drainage obstruction. A downside of drip irrigation drainage is wetting beddings, so measures like absorbent dressings, plastic sheets, and bed protectors are used to keep the patient dry. Using two thin catheters—one for inflow and the other for negative-pressure suction (e.g., gastrointestinal decompressor)—can mitigate this issue.
(3) Surgery to eliminate dead space: For chronic suppurative osteomyelitis of the femur or tibia with large dead spaces after lesion clearance, a pedicled muscle flap can be used to fill the cavity. Care must be taken to avoid injuring the flap's blood vessels and nerves, and the flap should not be too large to prevent torsion at the pedicle.
(4) Resection of Diseased Bone For some cases of chronic osteomyelitis, such as in the ribs, upper or middle portion of the fibula, or ilium, surgical resection of the affected part may be considered.
(5) Amputation. This method should only be considered after careful deliberation when the infection cannot be controlled, the affected limb has completely lost its function, or even when the patient's life is at risk.
The management of gunshot wounds leading to chronic suppurative osteomyelitis requires thorough debridement of the lesion and radical treatment with drip drainage.
