• Users Online: 40
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 

 Table of Contents  
Year : 2015  |  Volume : 8  |  Issue : 1  |  Page : 42-45

Actinomycosis knee joint: An atypical presentation

1 Department of Orthopaedics, New Medical College and Hospital, Government Medical College, Kota, Rajasthan, India
2 Department of Pathology, Government Medical College, Kota, Rajasthan, India

Date of Web Publication13-Jun-2016

Correspondence Address:
Surender Kumar
B-281, R.K. Puram, Kota - 324 010, Rajasthan
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0975-7341.183952

Rights and Permissions

We are reporting an unusual case of actinomycosis which presented to us as a osteolytic lesion in distal femur. Diagnostic confusion leads to delayed medical therapy, increased morbidity and involvement of nearby bone that is, patella. Actinomycosis being an endemic disease and its ability to mimic many skeletal pathology, this should also be included in the differential diagnosis specially when the patient did not fit in to primary diagnosis and respond favorably to treatment given.

Keywords: Actinomycosis, distal femur, osteolytic lesion

How to cite this article:
Goel R, Rai AK, Kumar S, Saxena R. Actinomycosis knee joint: An atypical presentation. J Orthop Traumatol Rehabil 2015;8:42-5

How to cite this URL:
Goel R, Rai AK, Kumar S, Saxena R. Actinomycosis knee joint: An atypical presentation. J Orthop Traumatol Rehabil [serial online] 2015 [cited 2021 May 8];8:42-5. Available from: https://www.jotr.in/text.asp?2015/8/1/42/183952

  Introduction Top

Actinomycosis is a rare, subacute to a chronic infection caused by a group of filamentous, Gram-positive, anaerobic to microaerophillic bacteria. The principal agent causing human infection is actinomycosis israelii.[1]

In the isolated form of actinomycosis, most common clinical presentation are of cervicofacial, thoracic, abdominal, and pelvic in women. Orthopaedic manifestations predominates in disseminated actinomycosis, in that too affection of lower extremity is rare.[1]

Its variable clinical presentation and tendency to mimic malignancy, leads to diagnostic confusion, and delayed therapy.[2],[3]

Our experience of an unusual case of actinomycosis affecting the bones around knee joint leading to the diagnostic confusion and delayed treatment, prompted us to report.

  Case Report Top

A 40-year-old housewife was admitted to respiratory medicine ward being treated for pulmonary tuberculosis and referred to us for complaints of pain and swelling right knee since last 6 months. Pain and swelling were insidous in onset. The pain was dull aching in nature and mild in intensity and aggrevated by weight bearing initially which later on gradually progressed in intensity and persisted at rest also. A history of loss of appetite and weight was present. History suggestive of evening rise of temperature and night cries was also present. The patient had a past history of pulmonary tuberculosis at the age of 20 years for which complete antitubercular course taken and patient declared cured.

On examination, patient was of average built and poor nutrition. Local examination of right knee exhibited diffuse tender swelling with normal overlying skin. The surface temperature was not raised. The range of motion of knee was restricted due to pain. Ipsilateral inguinal lymph nodes were enlarged, disrete, and nontender. Ipsilateral hip and ankle were normal.

Hematological parameter shows hemoglobin 8 g paercent, erythrocyte sedimentation rate was 45, increased leucocyte count with increased monocyte count. Rest all other organ function test were normal.

Radiograph knee including distal femur and proximal tibia anteroposterior and lateral view [Figure 1] showed osteolytic lesion of distal femur alongwith erosion of anterior cortex. Patella and proximal tibia was also involved. There was increased soft tissue shadow suggestive of swelling.
Figure 1: X-ray knee joint anteroposterior and lateral view showing lytic lesion in distal femur

Click here to view

Computed tomography scan right knee [Figure 2] also revealed cortical breech of distal femur. fine needle aspiration cytology from lesion showed nonspecific granulomatous chronic inflammatory tissue.
Figure 2: Computed tomography scan (axial plane) showing involvement of right knee along with cortical breech

Click here to view

Considering the patient's present and past history we made our diagnosis as tubercuosis knee and treated the patient with immobilization and continued category I antitubercular drug regime through DOTS center and kept the patient in follow-up.

When even after 2 months of antitubercular drugs treatment patient did not improve, we subjected her to open biopsy and sent it for histopathological examination.

Histopathological examination of tissue revealed an extensive area of acute inflammatory exudates, foamy histiocytes, and occasional giant cells. A central hematoxyphyline colony was seen in focal areas with surrounding pinkish material [Figure 3]. Colonies were periodic acid schiff positive, granular and did not show any hyphae [Figure 4]. These features were consistent with a diagnosis of actinomycosis.
Figure 3: Microphotograph (×400): Section reveals central hematoxylin colonies surrounded by neutrophilic exudates (white arrow)

Click here to view
Figure 4: Microphotograph (×100): Periodic acid schiff positive colonies

Click here to view

On the basis of the biopsy report, we treated the patient by debridement and synovectomy of knee joint and high dose intravenous penicilline G for 6 weeks on an indoor basis. On subsidence of swelling and pain and when the patient was able to walk [Figure 5] we started the oral capsule amoxycilline 500 mg thrice a day along with Vitamin B for 1-year and kept the patient in regular follow-up. Now the patient is pain free, able to walk without assistance but had restricted the range of motion of the knee.
Figure 5: Clinical photograph of patient in standing position with reduced swelling of the right knee

Click here to view

  Discussion Top

Actinomycosis is a bacterial infection which is caused by anaerobic Gram-positive actinomycetes species, a natural flora of oral cavity, gastrointestinal tract, and urogenital tract.[4],[5] Atleast 30 species have been identified, most common of which causing infections are Actinomyces israelii, Actinomyces naeslundii, Actinomyces odontolyticus.[6] Actinomyces are closely related to Nocardia species and due to their branching filaments both were once considered fungi.[7]

Actinomycosis is an endemic and occurs worldwide. It has no predilection for any age group, sex, race, or any occupation.[8] It usually involves cervicofacial, thoracic and abdominopelvic region, and central nervous system (CNS).[7] It can infect any part of the body, but the involvement of extremity is least likely.[9] Brown [9] in his large study of 181 patients found extremity involvement of eight cases in that too lower limb was involved in five cases (2.8%).

Clinically actinomycosis present as a localized chronic inflammation with fever and leucocytosis. Clinical suspician of diagnosis is difficult as only a few patients have sinuses and discharging thick yellow-green pus.[9] Radiologically there are a muliple lesion of circular shape and slightly sclerotic margins.

The histopathological diagnosis is based on finding the granules along with clubs and Gram-positive branching bacilli in tissue exudates or on culture.[9] Actinomyces are difficult to culture as immediate transfer to microbiology laboratory in the anaerobic medium is required. A high index of suspicion necessary since the grains may be scarce. Gram stains shows Gram-positive microcolonies intermixed with filaments and coexisting companion bacterias which may be Gram-positive or negative cocci or bacilli.

Treatment for actinomycosis is consist of surgical debridement and prolonged antibiotic therapy. Penicilline G is the drug of choice.[7] Therapy should be individualized but high doses (18-24 million units/day) of penicilline for a period of 2 for 6 weeks followed by oral penicilline or amoxycilline to complete 6 to 12 months is recommended.[6]

Actinomycosis has a favourable outcome if it is timely diagnosed and adequately treated otherwise haematogenous dissemination may occur, specially in the thoracic type. Disseminated disease can be wrongly taken as a metastatic disease as it presents with multiple nodules virtually in every tissue and organ of the body.[6],[10]

Mortality due to actinomycosis ranges from 0% to 28% depending mainly on the site of infection and the time of diagnosis and treatment.[7],[11] CNS actinomycosis has the highest toll of mortality and neurologic sequelae being in half of such cases.[11]

  Conclusion Top

Actinomycosis is a rare disease encountered by an orthopedician and that too of lower limb. Because of its variety of clinical presentation reported in the literature and its ability to mimic different diseases, it create diagnostic confusion and leads to delayed appropriate medical therapy. We emphasize the importance of keeping it as a differential diagnosis and early diagnosis with simple gram stain, as delayed treatment can lead to increased morbidity and even mortality.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Polenakovik H, Polenakovic S. Actinomycosis E-medicine; April 1-16,2006.  Back to cited text no. 1
Sehouli J, Stupin JH, Schlieper U, Kuemmel S, Henrich W, Denkert C, et al. Actinomycotic inflammatory disease and misdiagnosis of ovarian cancer. A case report. Anticancer Res 2006;26:1727-31.  Back to cited text no. 2
Malik AI, Papagrigoriadis S, Leather AJ, Rennie JA, Salisbury JR, Beese RC. Abdominopelvic mass secondary to Actinomyces israelii mimicking cancer: Report of two cases. Tech Coloproctol 2005;9:170-1.  Back to cited text no. 3
Sarkonen N, Könönen E, Summanen P, Kanervo A, Takala A, Jousimies-Somer H. Oral colonization with Actinomyces species in infants by two years of age. J Dent Res 2000;79:864-7.  Back to cited text no. 4
Nikolaitchouk N, Hoyles L, Falsen E, Grainger JM, Collins MD. Characterization of Actinomyces isolates from samples from the human urogenital tract: Description of Actinomyces urogenitalis sp. nov. Int J Syst Evol Microbiol 2000;50 Pt 4:1649-54.  Back to cited text no. 5
Russo T. Actinomycosis. In: Kasper DL, Fauci AS, Longo DL, Braunwald E, Hauser SL, Jameson JL, editors. Harrison's Principles of Internal Medicine. 16th ed. USA: McGraw-Hill; 2005. p. 937-9.  Back to cited text no. 6
Smego RA Jr, Foglia G. Actinomycosis. Clin Infect Dis 1998;26:1255-61.  Back to cited text no. 7
Jacobs RF, Schutze GE. Actinomycosis. In: Behrman RE, Kliegman R, Jenson HB, editors. Nelson Textbook of Pediatrics. 16th ed. Philadelphia: WB Saunders; 2000. p. 822-4.  Back to cited text no. 8
Brown JR. Human actinomycosis. A study of 181 subjects. Hum Pathol 1973;4:319-30.  Back to cited text no. 9
Louerat C, Depagne C, Nesme P, Biron F, Guerin JC. Disseminated actinomycosis. Rev Mal Respir 2005;22:473-6.  Back to cited text no. 10
Smego RA Jr. Actinomycosis of the central nervous system. Rev Infect Dis 1987;9:855-65.  Back to cited text no. 11


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Case Report
Article Figures

 Article Access Statistics
    PDF Downloaded122    
    Comments [Add]    

Recommend this journal