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| CASE REPORT |
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| Year : 2020 | Volume
: 6
| Issue : 2 | Page : 163-165 |
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Adult pseudo-tumor-like subacute osteomyelitis
Teka Maher, Zaier Akram Yassine, Ben Hnia Majdi, Ben GHozlen Hazem, Abid Faouzi
Department of Orthopaedics and Trauma, Taher Sfar Hospital of Mahdia, Mahdia, Tunisia
| Date of Submission | 29-Oct-2020 |
| Date of Decision | 09-Sep-2020 |
| Date of Acceptance | 17-Dec-2020 |
| Date of Web Publication | 31-Dec-2020 |
Correspondence Address:
Dr. Teka Maher
Department of Orthopaedics and Trauma, Taher Sfar Hospital of Mahdia, Mahdia
Tunisia
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/2455-3719.305874
Hematogenous osteomyelitis in adults is rare, and its subacute form is exceptional after the age of 20. It' is usually clinically latent which explains the difficulty of the diagnosis. The first differential diagnosis is bone tumors. It is known for its poor clinical and biological presentation despite a rich radiological aspect. Magnetic resonance imaging (MRI) is the examination of choice to confirm the diagnosis. The main differential diagnosis are primary and secondary bone tumors. The treatment is based on surgery and precise antibiotic therapy. Our patient is 52 years old who had pain in his left thigh, a discrete inflammatory syndrome without fever. He underwent standard X-ray, scintigraphy, and MRI, leading to finding an intraosseous lytic process with rupture of the cortical bone. The diagnosis of staphylococcal osteomyelitis was confirmed thanks to surgical biopsy and bacteriological sample, and his treatment was completed with specific antibiotic therapy.
Keywords: Adult, osteomyelitis, subacute
How to cite this article:
Maher T, Yassine ZA, Majdi BH, Hazem BG, Faouzi A. Adult pseudo-tumor-like subacute osteomyelitis. J Limb Lengthen Reconstr 2020;6:163-5 |
| Introduction | |  |
Subacute osteomyelitis in adults is very rare, and it is usually clinically latent, difficult to diagnose, and, most of the time, confused with a malilgnant process.
| Patient and Observation | | |
A 52-year-old patient presented with no previous known medical condition, who checked in for pain in the left thigh evolving for 2 weeks with no associated fever. Clinical examination showed an apyretic patient in good condition; the palpation of the upper third of the external side of the left thigh provoked an unsustainable pain. There were neither signs of local inflammation nor palpable mass, and the patient had normal joint mobility. Biological examination showed an inflammatory syndrome (C-reactive protein at 10, erythrocyte sedimentation rate [ESR] at 50, and white blood cells count at 10,000). A standard X-ray of the left thigh showed a bone gap image located in the upper third of the femoral shaft with a rupture of the antero-external cortical bone and no reaction in the periosteum [Figure 1]. The scintigraphy showed a small hot spot in the same spot [Figure 2]; the magnetic resonance imaging (MRI) objectified an intraosseous lytic process with a rupture of the cortical bone [Figure 3]. Surgical biopsy with a bacteriological sample confirmed the diagnosis of staphylococcal osteomyelitis [Figure 4]. The lesion was excised and curetted, and the skin was closed under a drain that was kept for 10 days. The patient was put on antibiotics with a favorable outcome after 3 months of treatment and a good bone reconstruction after 6 months [Figure 5]. Full-weight bearing was not allowed for 45 days to prevent pathological fracture. | Figure 1: The standard X-ray of the pelvis showing a lacunar lesion of the upper 1/3rd of the left femur with rupture of the cortex and absence of periosteal reaction
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 | Figure 2: Bone scintigraphy showing localized hyperfixation of the upper 1/3rd of the left femur
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 | Figure 3: Magnetic resonance imaging coronal slices showing an external cortico-medullary lesion in hypo-T1, taking the contrast in fat-saturated T1 with infiltration of the soft parts and rupture of the bone cortex
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 | Figure 4: Anatomopathological section (H and E, ×100) showing a lymphoplasmacytic infiltrate, suggesting a chronic inflammatory process
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 | Figure 5: The standard X-ray of the frontal left femur showing a bone reconstruction at 6-month follow-up
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| Discussion | | |
The rarity of osteomyelitis in adults is linked to the vascularization of adult bone. After fusion of the growth cartilage, there is a communication between the epiphyseal and metaphyseal network, which explains the greater frequency of joint damage.[1] On the other hand, the fibrosis of the adult periosteum and its adhesion to the bone cortex explains the rarity of abscesses under periosteum.
The pathogenesis of subacute osteomyelitis can arise from the following two mechanisms:[2]
- Either a modified form of acute osteomyelitis, following insufficient or inappropriate treatment
- Or it is a truly primitive form in favor of a greater resistance of the individual to infection or a lower virulence of the germ.
The clinical presentation is not very suggestive of the diagnosis,[2],[3] hence local moderate tenderness is often the revealing sign evolving for <2 weeks. The absence of general signs of infection is constant. The biological signs are also not very evocative. Blood cultures are most often sterile. Leukocytosis is usually normal. The ESR is sometimes moderately elevated.
This poor clinical and biological picture is in contradiction with its radiological aspects that are very suggestive of a serious bone lesion. It is most often a lytic metaphyseal lesion with peripheral condensation. The location can be as much metaphyseal, diaphyseal, or epiphyseal. Due to the rarity of infection in adults, the first suspected diagnosis is a bone tumor.[2] The tumors most often mentioned are osteoid osteoma, osteosarcoma, and Ewing's sarcoma. At an older age (more than 50 years), it is first necessary to mention a secondary tumor (metastasis). The scintigraphy does not seem to be of much help, unlike acute osteomyelitis. Fixation is normal or slightly increased. MRI is currently the examination of choice in the exploration of the osteoarticular system, and in particular in infectious pathology.[4] The MRI appearance is that of an intramedullary abscess. The central cavity appears on T1 images in hypo signal and on T2 images in hyper signal. The walls of the abscess are covered with a richly vascularized granulation tissue appearing as T1 isosignal and enhancing after the injection of gadolinium. A surgical biopsy is recommended by the majority of authors; it helps to rectify the diagnosis, especially to eliminate a tumoral lesion. It must be planned on the topographical data of the palpation and imaging, and always consider the subsequent removal surgery, in case of tumor. In our case, the lesion was antero external and we opted for a Smith–Petersen incision.
The surgery consists of the evacuation of the abscess, curating the necrotic debris, and taking samples for culturing and antibiogram.[5] Staphylococcus aureus has been mostly isolated in the cultures. Treatment based on an oral antistaphylococcal antibiotic is an essential adjuvant.[5] It should be continued for 2–3 months until the ESR is normalized. The outcome of the osteomyelitis is most often favorable.
| Conclusion | | |
Subacute osteomyelitis in adults is rare. It remains difficult to diagnose despite all modern imaging means. It poses the problem of an atypical radiological image, which leads to considering tumors as the first diagnosis, especially malignant ones. The use of surgical biopsy for diagnostic and sometimes therapeutic purposes (excision curettage) is systematic. The constantly favorable evolution under adapted antibiotic therapy reveals the good prognosis of these lesions.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Evrard J. Hematogenous osteomyelitis in the adult. Rev Chir Orthop Reparatrice Appar Mot 1986;72:531-9.  |
| 2. | Shih HN, Shih LY, Wong YC. Diagnosis and treatment of subacute osteomyelitis. J Trauma Inj Infect Crit Care 2005;58:83-7. |
| 3. | Hayes CS, Heinrich SD, Craver R, MacEwen GD. Subacute osteomyelitis. Orthopedics 1990;13:363-6. |
| 4. | Grey AC, Davies AM, Mangham DC, Grimert RJ, Ritchie DA. The 'Penumbra sign' on Tl-weighted MR imaging in subacute osteomyelitis: Frequency, cause and significance. Clin Radiol 1998:6;587-92. |
| 5. | Damir D, Toader E, Creţu A. Correlational aspects of hematogenous osteomyelitis in children and adults. Rev Med Chir Soc Med Nat Iasi 2011;115:269-76. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
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