Tubercular Infection Presenting as Sinus Over Ankle Joint after Knee Replacement Surgery

Sir, Infection of the joint, following joint replacement surgery, is one of the most dreaded complications. The reason for this is the morbidity and expenditure involved in treating such infections. Common organisms causing infection are coagulase-negative staphylococci, staph aureus, mixed flora, streptococci, etc. We treated one patient of knee joint replacement, who later developed tuberculous infection. This infection manifested as sinus tract opening at ankle joint. Only one such case has been reported in literature.


Tubercular Infection Presenting as Sinus Over Ankle Joint after Knee Replacement Surgery
Sir, Infection of the joint, following joint replacement surgery, is one of the most dreaded complications. The reason for this is the morbidity and expenditure involved in treating such infections. Common organisms causing infection are coagulase-negative staphylococci, staph aureus, mixed flora, streptococci, etc. We treated one patient of knee joint replacement, who later developed tuberculous infection. This infection manifested as sinus tract opening at ankle joint. Only one such case has been reported in literature.
This patient, a 72-year-old woman, presented with complaints of a non-healing wound over inner aspect of right ankle joint for the last 3 years. There was intermittent bloody-to-clear discharge from the wound. The wound used to heal for a short period and then recur spontaneously. There was no history of fever, trauma or purulent discharge. Past history of the patient was very eventful. She had undergone knee replacement surgery in 1987, which had to be repeated because of loosening of prosthesis. It was 1 month after the second surgery that the patient developed swelling in ankle region. The swelling was diagnosed as isolated abscess, which was incised and drained. The patient was put on broad-spectrum antibiotics, but the incision site turned into chronic sinus. Pus cultures were sterile. Blood cultures were not done as it was a localized swelling with no systemic manifestations like fever. Later, biopsy of sinus wall was done, which revealed tuberculosis. Though acid fast bacilli staining was negative, the patient was put on antitubercular treatment for 9 months. The sinus healed temporarily, just to recur after a few months. Local examination showed a sinus opening just above the medial malleolus over the right ankle joint. The surrounding skin was healthy. We observed another 2 × 2 cm-sized firm nontender swelling in the region of medial head of gastrocnemius muscle. Sinogram was done, which revealed sinus tract extending from sinus opening at ankle joint, upwards towards the knee joint [ Figure 1]. Excision of sinus tract was planned and patient taken up for surgery. Methylene blue was injected into the sinus tract and dissection made circumferentially around the tract. There was approximately 20 cm long tract starting from medial aspect of knee joint and extending upwards through the gastrocnemius muscle and ending in a closed cavity at ankle joint through which knee prosthesis could be felt [ Figure 2]. The whole sinus tract was excised [ Figure 3] and the blind cavity at upper end closed. Histopathology of the sinus tract biopsy suggested tuberculosis. The patient was again put on a 9-month course of antitubercular treatment, after which the patient became asymptomatic.
Tubercular infection of the knee joint has been mentioned in literature, [1][2][3] but infection of a replaced knee joint with Mycobacterium tuberculosis is not common. [4] Cases of granulomatous inflammation following joint replacement secondary to foreign body reaction have also been reported in literature. [5] In this case, the possible explanation could be local reactivation of quiescent tuberculosis of the knee joint. The patient had undergone replacement of knee prosthesis due to loosening of previous prosthesis, following fall. Fall might be a coincidental happening, and the actual cause of loosening of prosthesis could be tuberculosis infection. Cause for activation of tuberculosis could be foreign body reaction secondary to metallic prosthesis. There has been only one previous reported case of tuberculosis and foreign body granulomatous reactions involving a total knee prosthesis. [6] In the Indian scenario, where tuberculosis is very common, we strongly recommend pre-surgical diagnostic tests to rule out tuberculosis. Sir, Malaria, a protozoal disease, caused by genus plasmodium, is prevalent in about 100 countries worldwide [1] and is a major cause of morbidity and mortality especially in sub-Saharan Africa, Southeast Asia, and Latin-America. [2] In India about 1.65 million cases were reported (with 943 deaths) during the years 2003 and 2004. [1] Malaria is an endemic disease in the city of Mangalore, Karnataka, since 1994-1995.

Sanjeev Uppal, Ramneesh Garg
Cardiac involvement in malaria has not been studied widely. There have been few reports of experimental and postmortem studies indicating myocardial involvement in malaria. [2][3][4][5][6][7] We investigated the extent of cardiac involvement in malaria in the clinical situation, by analyzing the occurrence of acute myocardial infarction (AMI) in patients with malaria and comparing it with AMI in nonmalarial patients.
A retrospective observational study of 38,919 in-patients of Dr. TMA Pai Rotary Hospital, Mangalore, was done from the year 1995 to 1998, and it was found that among 1531 malarial patients, 22 had AMI (1.43%), a statistically significant (P , 0.05) occurrence, as compared to AMI among all in-patients who were in for complaints other than malaria, (0.82%), reflecting the possibility of myocardial damage in malaria. Analysis had been started from 1995, as malaria resurged in Mangalore city from 1995 onwards. Diagnosis of malaria cases had been established by the Quantitative Buffy Coat (QBC) test [8] and diagnosis of myocardial infarction had been established by the treating physicians following standard electrocardiogram (ECG) changes and cardiac biomarker profiles.