Tuberculosis (TB) of the musculoskeletal system is an uncommon infection caused by tuberculous bacilli and constitutes 1% to 5% of all forms of TB.1Tri-compartmental tubercular arthritis of knee masquerading as popliteal fossa tumor: A case report.,2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report. The incidence of skeletal TB is increasing due to the emergence of multidrug-resistant mycobacterium, an increase in the number of immunocompromised patients, and the AIDS pandemic. Although no age is exempted, its incidence in elderly and debilitated patients is high.2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report. Musculoskeletal involvement is through hematogenous spread, often from a primary focus frequently the lungs.2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report. A total of 30% of skeletal TB involves the joints, the knee being the third most commonly affected after the spine and the hip.2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report. Knee TB commonly presents as synovitis or arthritis, and infected Baker’s cyst is a rather rare presentation of knee joint TB.2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report., 3Isolated tuberculosis of the popliteal cyst., 4Bianco G. Paris A. Venditti M. Calderini C. Anzivino C. Serra P. Popliteal (Baker’s) cyst in a patient with tubercular arthritis—report of a case and review of the literature. It is believed to result from propagation of TB of the knee joint into the cyst, as approximately one half of the Baker’s cyst communicates with the knee joint.3Isolated tuberculosis of the popliteal cyst. The Baker’s cyst is a distension of the gastrocnemius-semimembranosus bursa of the knee, which communicates with the posterior portion of the joint capsule and, therefore, infected Baker’s cyst usually appears as swelling in the medial aspect of the popliteal fossa.2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report. For TB popliteal bursitis at the lateral aspect of the popliteal fossa, it may be an extra-articular extension of TB of the knee joint via the popliteal hiatus. Chemotherapy remains the cornerstone of treatment; surgery including joint debridement, synovectomy, and cyst excision is indicated in cases not responding to drug treatment.2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report. Open resection of the popliteal cysts are associated with an extensive approach, high risk of important anatomical structures injuries, potential risk of wound complications, prolonged recovery time, and an unacceptable risk of cyst recurrence.2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report.,5Baker's cyst: Diagnostic and surgical considerations., 6Han J.H. Bae J.H. Nha K.W. et al.Arthroscopic treatment of popliteal cysts with and without cystectomy: A systematic review and meta-analysis., 7Zhou X.N. Li B. Wang J.S. Bai L.H. Surgical treatment of popliteal cyst: A systematic review and meta-analysis. Arthroscopic treatment of the Baker’s cyst has the advantage of minimally invasive surgery and mainly corrects the valvular mechanism between the knee joint and the cyst, which restores a bidirectional fluid flow followed with excision of cystic walls.8Malinowski K. Hermanowicz K. Góralczyk A. et al.Possible approaches to endoscopic treatment of popliteal cysts: From the basics to troublesome cases. To the best of our knowledge, there is no report of the minimally invasive resection of the popliteal cysts at the lateral aspect of the popliteal fossa. The purpose of this Technical Note is to describe the details of endoscopic resection of recalcitrant tuberculous bursitis at the lateral aspect of the popliteal fossa. It is indicated for tuberculous bursitis at the lateral aspect of the popliteal fossa that is recalcitrant to chemotherapy. It is contraindicated for cyst at the medial side of the popliteal fossa or the lesion is a solid tumor rather than a cystic lesion (Table 1).

Table 1Indications and Contraindications of Endoscopic Resection of Recalcitrant Tuberculous Bursitis of the Popliteal Fossa

DiscussionTuberculous popliteal bursitis is a rare disease entity. To achieve a definitive diagnosis, it is essential to identify Mycobacterium TB. Bone and joint TB are, however, paucibacillar. Many times, the Ziehl–Nielsen test is negative, and it becomes necessary to wait for the Lowenstein culture results.2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report. Synovial biopsy is also an important and diagnostic method to ascertain the causative pathogen.2Suresh Babu T.V. Kiran K.R. Deepti K. Tuberculous arthritis of knee presenting as Bakers cyst: A case report. Moreover, the synovial biopsy is mandatory to establish the diagnosis histopathologically, and one does not need to wait for a culture result.1Tri-compartmental tubercular arthritis of knee masquerading as popliteal fossa tumor: A case report.,9Opara T.N. Gupte C.M. Liyanage S.H. Poole S. Beverly M.C. Tuberculous arthritis of the knee with Staphylococcus superinfection. Synovial biopsy can be performed via the knee arthroscopy, which is a safer procedure. Endoscopic resection of the tuberculous popliteal bursitis is only indicated if the disease does not respond to chemotherapy. The important structures that are at risk include the common peroneal nerve, the tibial nerve, and the popliteal artery and vein. In this described technique, the common peroneal nerve is already identified and protected during establishment of the proximal portal. The risk of injury to the tibial nerve and the popliteal artery and vein can be minimized when the safety measures of the technique are followed strictly.This minimally invasive technique has the advantage of less soft-tissue trauma, better cosmetic results, and fewer wound complications. The potential risks of this technique include recurrence of the lesion, nerve injury, vascular injury, hematoma collection, and spreading of infection (Table 3). This is technically demanding and should be performed by experienced knee arthroscopists.

Table 3Advantages and Risks of Endoscopic Resection of Recalcitrant Tuberculous Bursitis of the Popliteal Fossa