Locked knee is an orthopaedic condition requiring urgent treatment. Although the condition can be diagnosed via history, physical examination and imaging studies, the cause of the mechanical obstruction may only be apparent during arthroscopic examination of the knee joint. It is known that imaging plays a role in evaluating the integrity of intra-articular structures, however in some atypical cases, imaging cannot identify the definitive cause of locked knee. Here we report on two cases of locked knee, due to uncommon conditions which were unobservable via normal imaging studies.

Osteomyelitis accounts for the majority of bone infections with open fractures have higher rates of osteomyelitis in contrast to closed fractures. It is usually seen in open fractures with substantial contamination and soft tissue damage, as well as after internal fixation. Chronic osteomyelitis is recognised by continuance presence of microorganisms, sequestrum, low-level of inflammation and fistulae. The infection can be contained to the bone or spread to the soft tissues, periosteum, and bone marrow. The predominant aetiological agents are Staphylococcus aureus, Streptococcus species, Enterococcus species, Pseudomonas aeruginosa and Enterobacteriaceae, but rarely due to Bukholderia pseudomallei. We report a case of post-traumatic chronic osteomyelitis of tibia due to Bukholderia pseudomallei. This case emphasises the significance of considering melioidosis in patients with uncontrolled diabetes mellitus who have undergone surgical intervention and reside in a region where infectious diseases are prevalent.