患者女,61岁。无明确外伤史,因左膝疼痛、肿胀、活动受限1个月入院。体检:左大腿下端、膝部、小腿上端皮肤完好,稍肿胀,以内侧明显,外观无明显畸形,皮温稍高,内侧局部压痛(+)。实验室检查:血常规:红细胞计数2.4×1012/L,血红蛋白89.0 g/L,红细胞压积23.2%。影像学检查:左膝关节X线平片示左膝关节诸骨未见明显骨质破坏,骨皮质无中断,未见明显骨膜反应(图1); Female patient, 61 years old. No clear history of trauma, left knee pain, swelling, limited mobility 1 month admission. Physical examination: the left lower thigh, knee, upper leg skin intact, slightly swollen to the inside obvious, the appearance of no significant deformity, skin temperature slightly higher, medial tenderness (+). Laboratory tests: blood: erythrocyte count 2.4 × 1012 / L, hemoglobin 89.0 g / L, hematocrit 23.2%. Imaging examination: left knee X-ray showed no obvious bone destruction of the left knee joint, cortical bone without interruption, no significant periosteal reaction (Figure 1);