Tuberculosis (TB), once a disease confined to undeveloped or developing nations is currently in resurgence due to pandemic human immunodeficiency virus infection and immigration from endemic areas. TB is also known as the ‘great mimicker’. Extra-pulmonary tuberculosis affecting the knee is rare in all forms of TB (0.1-0.3%). Here, we report a case of isolated highly erosive TB knee in a previously fit Burmese migrant worker. He presented with after a history of fall into a drain. The patient also reported pain and swelling over his left knee for the previous three years. He had been treated for a bacterial infection of the knee in another hospital but defaulted due to financial constraints. Arthrotomy of the knee was performed including washout. Diagnosis of TB of the knee was made based on the synovial fluid and tissue culture. Treatment with antituberculosis drugs was then initiated.

Heterotopic ossification (HO) is the growth of bone in soft tissue, and can be broadly classified into neurogenic, genetic and traumatic causes. The pathophysiology of HO remains unknown. This disorder is extremely rare in infants and can mimic or coexist with thrombophlebitis, cellulitis or osteomyelitis. Most importantly, HO has to be differentiated from bone-forming tumours such as osteosarcoma and osteochondroma. We report a case of traumatic HO in a fiveday- old newborn following intravenous cannulation of the right wrist and left ankle, with the latter complicated with osteomyelitis. We highlight the clinical and radiological features of HO and differential diagnoses of soft tissue ossification in early childhood.