Sacral Emphysematous Osteomyelitis Caused by Escherichia coli after Arthroscopy of the Knee

Emphysematous osteomyelitis of the spine: a case report and case based review of the literature

BACKGROUND/OBJECTIVE

Emphysematous osteomyelitis (EO) of the spine is an uncommon type of osteomyelitis characterized by intraosseous gas-formation in the vertebrae. The objective of this report is to present a rare case of spine EO in a patient with emphysematous cystitis. A case-based review of the literature on spinal EO was also performed as an update to the relevant literature of this rare infection.

CASE DESCRIPTION/METHODS

A 55-year-old female with diabetes mellitus and peripheral vascular disease (PVD) presented to our institution with recurrent falls, fatigue, and low back pain. Computed tomography (CT) and magnetic resonance imaging (MRI) scans confirmed emphysematous cystitis and EO at L4. Given the diffuse involvement, surgical intervention was deferred for IV antibiotic therapy. A case-based review was also conducted by searching the SCOPUS and PubMed databases for the following terms: "emphysematous osteomyelitis", "gas", and "spine". Only publications in English were included in this review.

KEY CONTENT/FINDINGS

Urine/blood cultures identified Klebsiella pneumoniae. After initial improvement with six weeks of broad-spectrum antibiotics, the patient re-presented with recurrent fevers and fatigue. Despite maximal medical therapy, the patient expired 2 months later due to multi-organ system failure. Including the present report, only 29 cases of spine EO have been described in the literature. Patients almost consistently presented with fever, elevated inflammatory markers, and localized pain. Most cases of spinal EO (89.7%) were monomicrobial. Escherichia coli (37.9%) and Klebsiella pneumoniae (27.6%) were the most causative organisms identified. Medical treatment universally consisted of broad-spectrum IV antibiotics prior to tailoring. Debridement and decompression, with or without fusion, were the main operative procedures performed for spine EO. Outcomes following spinal EO are varied with a 44.4% mortality rate.

CONCLUSIONS

We present a case of EO of the spine and concomitant emphysematous cystitis with Klebsiella pneumoniae and a case-based review of the literature. Appropriate work up for this rare infection should include inflammatory markers, cultures, and CT/MRI imaging. Treatment consists of IV antibiotics with anaerobic and gram-negative coverage. However, treatment guidelines and operative indications for spinal emphysematous osteomyelitis remain unclear.

A Rare Facultative Anaerobe Causing Emphysematous Osteomyelitis of the Pubic Bone

Emphysematous osteomyelitis is an uncommon and fatal disease that can only be confirmed with a contrast-enhanced CT scan showing characteristic features of air locules within the bone. It usually occurs in the setting of existing comorbidities and suppressed immune system resulting in widespread bacteremia which may be mono or poly-microbial. Presented here is a case of this disease caused by an unusual anaerobe affecting the pubic bone. This case emphasizes the importance of early imaging as it is crucial for the diagnosis and can facilitate early aggressive management. Moreover, it highlights the importance of early intravenous antibiotics and surgical intervention, which can be life-saving and result in a better outcome in the future.

Atypical infectious spondylitis with reduced bone marrow enhancement: "black vertebra sign"

BACKGROUND

A few patients suspected of having infectious spondylitis exhibited a reduced enhancement pattern on postcontrast T1-weighted (T1W) magnetic resonance imaging (MRI).

PURPOSE

To investigate the characteristics of infectious spondylitis patients who exhibited reduced vertebral enhancement.

MATERIAL AND METHODS

From January 2010 to November 2017, 456 patients with findings suspicious for infectious spondylitis on 706 postcontrast T1W imaging were retrospectively evaluated. When an affected vertebra exhibited markedly reduced enhancement compared to normal bone marrow (BM), the vertebra was termed a "black vertebra." MRI and computed tomography (CT) imaging findings within two-week intervals and the patients' clinical characteristics were reviewed.

RESULTS

Ten patients (5 men, 5 women; mean age 66.4 years) whose MRI scans revealed the black vertebra sign were included. Among the 10 patients with black vertebrae, six patients exhibited signal voids in or around the affected vertebral bodies on T2-weighted (T2W) images. Eight patients showed air bubbles on CT images, suggestive of emphysematous infection. However, the typical image findings of infectious spondylitis were uncommon, namely, low BM signal intensity (SI) on T1W images (n=1) and intradiscal fluid-equivalent SI on T2W images (n=5) at an early stage. On follow-up MRI (average interval 7.2 weeks from initial MRI), available for five patients, marked progression of infection was evidenced by increased numbers of affected segments (n=3), low T1 SIs of the affected vertebrae (n=5), and increased contrast enhancement (n=3). Five patients underwent surgery to treat infections not controlled by antibiotics.

CONCLUSION

A black vertebra sign on postcontrast T1W imaging seems to reflect an early emphysematous infection.

Gas forming infection of the spine: a systematic and narrative review

PURPOSE

Gas forming infection (GFI) of the spine is a rapidly progressive and potentially life-threatening infection. It can be a consequence of aetiologies such as Emphysematous Osteomyelitis (EOM), Necrotizing Fasciitis (NF), and Gas-containing Spinal Epidural Abscess (Gas-containing SEA). This review aims to summarize the characteristics of these subtypes of GFI, describing their aetiology, diagnosis, management, and prognosis.

METHODS

PubMed, Embase, Web of Science and the Cochrane Database were systematically searched for studies reporting on gas forming infections of the spine or a known subtype. Cases of post-operative and iatrogenic spinal infection were excluded.

RESULTS

The literature review revealed 35 studies reporting on 28 cases of EOM, three cases of NF involving the spine and seven cases of Gas-containing SEA. Thirty studies reporting on 32 cases of GFI were available for data analysis. The mean age of the patients was 60.9 years and a concomitant diagnosis of diabetes mellitus was reported in 57.5% of patients infected. Fever and back pain were the most common presenting symptoms. The lumbar spine was the most commonly affected spinal segment. Mortality from EOM, NF and Gas-containing SEA were 34.8, 100 and 28.5%, respectively.

DISCUSSION

Gas forming infection of the spine is a rare condition with an extremely poor prognosis, requiring early and aggressive surgical treatment. A multi-disciplinary approach is necessary for management. Nonetheless, even in cases of early recognition and optimal management, multisystem failure may still occur, and mortality rates remain high due to the aggressive nature of this infection.

LEVEL OF EVIDENCE

Systematic review of level IV studies.

Intramedullary Antibiotic Delivery for Emphysematous Osteomyelitis of the Femur

The authors present a case of bilateral femoral emphysematous osteomyelitis caused by Escherichia coli in a 60-year-old woman with rheumatoid arthritis who was receiving long-term prednisone therapy. The infection in both femoral shafts was eradicated with surgical debridement, followed by insertion of intramedullary rods composed of culture-specific antibiotic cement into the femoral canals in conjunction with 6 weeks of intravenous antibiotics. The rods were subsequently removed, and no signs of further osteomyelitis were recognized at follow-up. To the authors' knowledge, this is the first case of its kind reported in the orthopedic literature. Emphysematous osteomyelitis, a rare and dangerous entity, can be successfully managed by intramedullary antibiotic delivery in the subacute setting. [Orthopedics. 2019; 42(1):e128-e130.].

Emphysematous Osteomyelitis of the Spine: A Case Report and Literature Review

Emphysematous osteomyelitis is a rare but potentially fatal infection. It is caused by gas-forming organisms and is characterized by the presence of intraosseous gas. A 75-year-old woman with untreated diabetes mellitus presented with difficulty in moving and anorexia. Laboratory studies revealed inflammation, a urinary infection, and diabetic ketoacidosis. Klebsiella pneumoniae was detected in both urine and blood cultures. Computed tomography and magnetic resonance imaging revealed emphysematous lesions in the paravertebral soft tissue, spinal canal, and iliopsoas muscle, with intraosseous gas at L1 and L2. These findings led to a diagnosis of emphysematous osteomyelitis. We herein review 35 reported cases of emphysematous osteomyelitis including our case.

Emphysematous osteomyelitis of the forefoot

Emphysematous osteomyelitis is a very rare, potentially fatal infection that requires immediate diagnosis and prompt treatment. Emphysematous osteomyelitis is usually considered whenever intraosseous gas is detected on imaging. Most organisms implicated in emphysematous osteomyelitis are members of the Enterobacteriaceae family or anaerobes; sometimes the infection is polymicrobial. We report a case of emphysematous osteomyelitis of the forefoot in a 33-year-old man with type 1 diabetes mellitus.