Ochronotic black meniscus during knee arthroscopy
A 30-year-old woman presented with complaints of pain in the left knee along with occasional episodes of locking for 1 year. Her physical examination revealed tenderness on the medial joint line and positive McMurray's test. Ordinary x-ray images of the knees were found to be normal. Magnetic resonance imaging (MRI) of the left knee revealed bucket handle tear of medial meniscus along with partial tear of anterior cruciate ligament. She was planned for arthroscopic partial meniscectomy in view of her complaints and MRI findings. During the arthroscopic examination of her left knee joint there was mild synovial hypertrophy and a bucket handle tear was found in the medial meniscus that appeared to be brownish black in color [Figures , ]. Anterior cruciate ligament was also found to be partially torn. Lateral meniscus and articular cartilage overlying medial femoral condyle also showed brownish black discoloration. Meniscectomy for bucket handle tear of medial meniscus was done and specimen was sent for histopathological examination.\nFurther investigations were planned for the diagnosis of ochronosis considering discoloration of the joint cartilage and menisci. The patient's freshly passed urine turned dark brown after addition of sodium hydroxide to the sample to facilitate oxidation. Ferric chloride test was also found to be positive. Histopathological examination of the excised tissue showed pigmentation and degenerative changes []. No pathological findings were detected with the detailed examination of the ear, sclera, skin, and cardiovascular system. Further treatment was done in the form of physiotherapy and by administering vitamin C and analgesics. After the medical and surgical treatment, the patient's complaints were alleviated and no complaints were registered, during the next follow-up.