Mycetoma (Madura Foot): Orthopaedic Assessment and Management

• Country of origin, rural residence, barefoot occupation, animal husbandry, thorn exposure.
• Duration — typically years. Ask specifically about the first swelling, not the first sinus.
• Painlessness. Pain suggests bone involvement or superadded pyogenic infection.
• Prior treatment: repeated incision and drainage, curettage, herbal or traditional remedies, and — critically — any previous antifungal or antibacterial course and its response (a response to co-trimoxazole retrospectively supports actinomycetoma).
• Function: ability to walk, wear footwear, work, school attendance for adolescents. Social stigma and treatment-abandonment risk are part of the history in this disease.

Inspection — patient supine, both lower limbs fully exposed to the knee, then standing and walking.

• Site: forefoot dorsum and sole most common; also ankle, leg, knee, hand, and the back or shoulder in head-load carriers.
• A firm swelling with multiple sinus openings at different stages — active discharging, granulating, and healed puckered scars. Grains may be visible at sinus mouths or expressible.
• Skin: hyperpigmented, thickened, sometimes hypopigmented over old scars. No overlying erythema unless secondarily infected.

Palpation — examiner's fingers pinch the mass between thumb and index finger.

• Consistency is woody-hard, non-tender — the key positive finding. Tenderness is a red flag for secondary infection or bone destruction.
• Assess mobility over deep fascia and bone: early lesions are mobile in the subcutaneous plane, late lesions are fixed, indicating deep extension.
• Squeeze a sinus onto a slide to express grains — record colour, size and consistency (black, firm and gritty suggests eumycetoma; red, yellow, white or pale and soft suggests actinomycetoma). Colour guides but does not diagnose.

Regional and systemic

• Regional lymph nodes: usually not enlarged; enlargement suggests secondary bacterial infection, lymphatic spread, or an alternative diagnosis.
• Neurovascular examination of the foot: sensation, pulses, and tendon function, since late disease and any planned resection depend on these.
• Systemic upset is absent in uncomplicated mycetoma; fever and malaise mean secondary sepsis.

False positives / traps: chronic pyogenic osteomyelitis with multiple sinuses is tender and febrile at flare; botryomycosis (a bacterial pseudomycetoma) produces grains and is a genuine mimic requiring culture; a neuropathic Charcot foot in an endemic country can coexist.

Principle: this is a medically curable infection. Do not operate first.

• Combination therapy is standard, both to improve efficacy and to prevent resistance. The classic backbone is co-trimoxazole (trimethoprim-sulfamethoxazole) given continuously for many months.
• For extensive or bone-involving disease, an intensive phase adds a second agent — historically amikacin in cycles (with audiometry and renal monitoring) or rifampicin; alternative and adjunct agents include amoxicillin-clavulanate, dapsone and linezolid depending on species and susceptibility. Species identification steers the choice: Nocardia and Actinomadura differ in susceptibility.
• Continue until sinuses close, the mass regresses, and ultrasound or MRI shows no residual grains — typically several months beyond apparent clinical cure.
• Monitoring: full blood count, renal and liver function, audiometry if aminoglycoside cycles are used, and folate supplementation considerations with long-term co-trimoxazole.
• Surgery is limited to drainage of secondary pyogenic abscess, debulking of a massive lesion impairing function, and rare sequestrectomy.

Principle: medical therapy alone rarely cures; the target is drug-induced shrinkage and encapsulation followed by wide excision.

• Antifungal therapy: itraconazole is the long-standing agent, with newer azoles (voriconazole, posaconazole) used for refractory disease; investigational agents including fosravuconazole have been evaluated in endemic-country trials. Absorption, adherence, drug interactions and cost dominate real-world outcomes. Terbinafine and amphotericin B have limited roles.
• Give a pre-operative course of several months where possible: it demarcates and firms the lesion, reduces its size, and makes an en bloc excision feasible with less tissue sacrifice.
• Surgery: wide local excision for localised disease; the operation is planned like a soft-tissue tumour resection.
• Continue antifungal therapy post-operatively for months, because microscopic grains beyond the resection margin are the source of recurrence.
• Recurrence is the defining problem and correlates with inadequate margins, extensive or multi-compartment disease, bone involvement, poor adherence and treatment interruption.

• Grain identified as actinomycete → medical therapy; no primary surgery.
• Fungal, localised subcutaneous mass, no bone involvement on MRI → antifungal course then wide local excision; expect cure.
• Fungal, limited bone cavitation confined to one ray or one tarsal bone → antifungal therapy plus wide excision including the involved bone (ray amputation, partial tarsectomy) — a local operation, not a below-knee amputation.
• Fungal, multi-compartment disease with extensive tarsal destruction, fixed deformity, non-functional foot → amputation after counselling.
• Failed prolonged medical therapy with progressive destruction, uncontrolled secondary sepsis, or intractable pain → amputation regardless of aetiology.
• Patient unable to sustain years of therapy or follow-up → be honest: a well-performed amputation with prosthetic rehabilitation may deliver better function than a failed limb-preserving programme, but this should never be the default in a resectable lesion.

Indication: localised eumycetoma, ideally after a pre-operative antifungal course, with MRI-defined extent within a resectable compartment. Contraindication: multi-compartment or extensive bone disease where margins are unachievable; actinomycetoma (medical disease); uncontrolled secondary sepsis (drain and treat first). Why this over debulking: grains lie beyond the visible mass; intralesional surgery reliably recurs.

• Position: supine, tourniquet on the thigh (exsanguinate by elevation rather than Esmarch over the lesion), foot on a sandbag, whole limb prepped.
• Imaging/equipment: MRI on the screen, image intensifier if bone resection planned, sterile marking of MRI-defined extent, oscillating saw and osteotomes, soft-tissue instruments, samples containers for microbiology and histology.
• Preparation: antifungal therapy continued perioperatively; treat any secondary bacterial infection first; optimise nutrition and anaemia; consent explicitly for possible ray amputation or conversion to a higher-level amputation.
• Approach: longitudinal incision in a line extensible proximally, encompassing an ellipse of all sinus-bearing skin — the sinuses are part of the specimen. Do not raise wide flaps over uninvolved tissue.
• Dissection: work in normal tissue outside the fibrous pseudocapsule; do not enter the mass. Take a cuff of normal fat, fascia and, where necessary, muscle. Divide involved tendon proximal and distal to disease. Send margins for histology.
• Reconstruction/resection: include involved bone en bloc (ray resection, partial tarsectomy). Reconstruct with local flaps, split-skin graft over a healthy bed, or free tissue transfer where available; plantar defects need durable, sensate cover.
• At-risk structures: posterior tibial neurovascular bundle in the medial hindfoot, dorsalis pedis and deep peroneal nerve dorsally, sural nerve laterally, flexor and extensor tendons, and the plantar weight-bearing skin envelope.
• Fixation: usually none; if a bone resection destabilises the medial column or hindfoot, plan arthrodesis or external fixation in the same setting.
• Closure: tension-free; consider delayed primary closure or negative-pressure dressing if contamination is a concern. Avoid drains through the resection bed where possible.
• Aftercare: elevation, non-weight-bearing until soft tissues are secure, then graduated weight-bearing with protective footwear; continue antifungal therapy for months; clinical and ultrasound/MRI surveillance for at least 2 years.
• Pitfalls: curetting through a sinus; failing to excise all sinus tracts; underestimating proximal fascial-plane spread on MRI; stopping antifungal therapy at wound healing.
• Salvage of failure: repeat wide excision if a discrete resectable recurrence; switch antifungal class with susceptibility guidance; amputation for extensive or repeated recurrence.

Indication: extensive bone destruction with a non-functional foot, failed prolonged medical and surgical therapy, life-threatening secondary sepsis, or intractable pain and disability.

• Level chosen by disease extent on MRI plus soft-tissue quality: ray amputation, transmetatarsal, Syme (rarely, given hindfoot involvement), or below-knee as the workhorse for extensive foot and ankle disease.
• Ensure the amputation level is through clinically and radiologically uninvolved tissue — amputating through diseased fascia produces stump recurrence.
• Preserve maximal length compatible with clearance; a long posterior myocutaneous flap for below-knee amputation.
• Continue antimicrobial therapy post-amputation for eumycetoma if margins are uncertain or proximal disease is suspected.
• Rehabilitation and prosthetic access must be planned before operating — in low-resource endemic settings, prosthetic availability and the patient's ability to farm barefoot again materially change the risk-benefit balance.
• Counsel on stigma and livelihood; involve community rehabilitation services.