當骨頭內在影像學上發現有空氣時(intraosseous gas)，但又沒有骨頭傷害時(如骨折或開刀)，須強烈懷疑是產氣性骨髓炎(emphysematous osteomyelitis)，此外骨髓炎以皮下氣腫(subcutaneous emphysema)來表現的個案，文獻上非常少。下面介紹一個少見的案例，其為一54歲糖尿病患者診斷為左脛骨遠端產氣性骨髓炎，卻以左小腿及大腿的皮下氣腫來表現，組織培養顯示沙門氏桿菌(Salmonella group C2)。
患者54歲男性，原住民，有糖尿病、高血脂、痛風及C肝等病史，於2個月前去南投打獵，因為動物的內臟不好保存，原住民習慣將捕獲的獵物現場剖肚，取出內臟生吃，但隔天就因為左髖部及膝蓋疼痛至本院急診求診，當時發燒到39.4度C、心跳103bpm，WBC正常，CRP:1.93，當時初步診斷為痛風性關節炎，因血糖高達549mg/dL，故因糖尿病控制不良住院。但關節痛仍然未改善，持續發燒，augmentin 無效，改為Ciprofloxacin ，HbA1C高達15.7%，故安排影像學檢查，X光無異常(如圖1):
圖1:lt knee X-ray: Soft tissue swelling, anterior knee.
圖2. CT: fasciitis with cellulitis of left thigh and arthritic arthropathy of bil knees.
之後患者症狀漸漸改善，而隨後的blood culture培養出兩套 Salmonella group C2，患者於住院一周後出院，診斷為L't knee arthritis, gout arthritis & septic arthritis，Salmonella bacteremia
之後過了兩個月，患者又因左膝疼痛3天，在外面診所以痛風治療無效，到我們急診求診，來的時候，呈現出toxic signs，有點喘、血壓不高、微燒(37.3C)，白血球18290並有band form:17%，其他data: CRP: 1.7, Blood gas: pH:7.416, HCO3:14.4, PCO2:22.9, BE:-8.2. Creat:1.7, BUN:49.6, ALT:92, AST:34, CPK:19, uric acid:8.3, sugar:229.
圖3.Soft tissue swelling with emphysema over the right thigh, knee and lower leg
圖4. CT: intramedullary gas in the distal third of the femur bone, with extensive subcutaneous emphysema
手術從大腿遠端外側進入，骨頭外側為正常、無膿瘍的表現，我們將脛骨遠端以氣鑽鑽開幾個洞，引流出白色無臭味的膿及氣體，並在左小腿及大腿內側做筋膜切開術，但卻無壞死性筋膜炎的表現。術中的培養結果仍然是Salmonella group C2，但血液培養沒長菌。
圖5.OP finding ，第一及第二次手術
抗生素醫感染科醫師建議使用Antibiotics treatment with Ciprofloxacin 200mg/vial 2 vial Q12H IV + Amoxicillin 1000mg＋Clavulanate 200mg 1 vial q8h IVD
Salmonella Osteomyelitis with Intraosseous Gas and Subcutaneous Emphysema in the Patient with Diabetes
Department of Surgery, Tainan Municipal Hospital
The presence of intraosseous gas in the absence of direct communication between bone and air, such as a compound fracture or recent surgery, is highly suggestive of emphysematous osteomyelitis. However there is rare osteomyelitis report with subcutaneous emphysema. We report a case of a 54-year-old male with diabetes mellitus who presented with emphysematous osteomyelitis of the left distal femur and subcutaneous emphysema of left thigh and calf. Specimen cultures in this case revealed a pure growth of Salmonella group C2.
The 54-year-old man with past medical history of poor controlled type 2 DM, hyperlipidemia, gout and hepatitis C was admitted through our emergency department due to left knee and hip joint pain for 8 hours. He was tachycardic (103bpm) and febrile (39.4C). Lab data showed normal white blood count, CRP:1.93, but high level of blood glucose level 549mg/dL, and HbA1c:15.7. Musculoskeletal soft tissue computed tomography (CT) showed fasciitis with cellulitis of left thigh and arthritic arthropathy of bil knees. He was diagnosed with gouty arthritis and septic arthritis and was treated with colchicines 0.5mg 1# qd and antibiotics. He was discharge 1week later after the symptoms improve. The following blood culture showed Salmonella group C2. The patient presented again to the emergency department 2months later with ongoing left knee pain for 3days, in vain with treatment of gout by clinic physician. He presented with toxic signs with dyspnea, dropped blood pressure, mild fever(37.3C) and leukocytosis(18290) with band form:17%. Lab data revealed: CRP: 1.7, Blood gas: pH:7.416, HCO3:14.4, PCO2:22.9, BE:-8.2. Creat:1.7, BUN:49.6, ALT:92, AST:34, CPK:19, uric acid:8.3, sugar:229. Physical exam showed local tenderness over lower third of left thigh and extensive crepitus extending from left groin to the left ankle. X-ray showed soft tissue tissue swelling with emphysema over lt thigh, knee and lower leg. Subsequent CT confirmed evidence of osteomyelitis with intramedullary gas in the distal third of the femur bone, with extensive subcutaneous emphysema involving the left hip, thigh and lower leg. Above knee amputation was suggested at first, but was refused by patient.
Through a lateral approach to the distal femur, penetration of bone was initially performed to drain the non-foul whitish intraosseous abscess and gas. The cortex of bone showed intact. Irrigation with H2O2 and debridement were performed. The fasciotomy of left thigh and calf was also done but no necrotizing fasciitis or abscess was found. Intraoperative cultures revealed Salmonella group C2. Blood cultures taken preoperatively showed no bacterial growth.
Antibiotics treatment with Ciprofloxacin 200mg/vial 2 vial Q12H IV + Amoxicillin 1000mg＋Clavulanate 200mg 1 vial q8h IVD was suggested by Infection doctor. The wounds were open cared with normal saline moist gauze packing bid. After 2 subsequent surgeries, he was eventually discharged 34 days after admission.
The patient had been regularly followed up and received oral antibiotics in my OPD for 1months after discharge. The wound condition was good.
This patient is a Taiwanese aborigines. He hunt the boar with his clansman. Then they usually ate the raw organs of boar with salt which may be the source of salmonella bacteremia. Osteomyelitis is a rarely reported manifestation of Salmonella infection. In 1981, Ram et al. were first to describe the radiological finding of intraosseous gas as a sign of osteomyelitis on computed tomography (CT). When seen in the extra-axial skeleton, intraosseous gas is virtually pathognomonic for emphysematous osteomyelitis. Diabetes mellitus and malignancy are common predisposing factors. Aggressive antimicrobial and surgical intervention is required as emphysematous osteomyelitis is associated with high mortality (32%) and significant morbidity, especially in diabetic patients.