Abstract:

Objective To discuss the clinical manifestations and diagnosis and treatment processes of one patient with subintimal hemangioma of the knee joint， and to improve the clinicians’ understandings of the disease. Methods The clinical data， imagological data， arthroscopic manifestations， and pathological results of one patient with subsynovial hemangioma of the knee joint were retrospectively analyzed， and the related literatures were reviewed. Results A 22-year-old female patient presented with intermittent left knee joint pain and swelling for 7 years. The physical examination results showed obvious tenderness in the inner and outer spaces of the left knee joint， and the range of motion of the left knee joint was decreased （0°－90°）.The ultrasound results showed that the hypoechoic light clusters were found between the deep layer of the vastus medialis tendon and the synovial tissue； the magnetic resonance imaging（MRI） results showed that the deep medial retinaculum of the left knee joint was swollen near the parapatellar soft tissue，which showed a slightly low signal on T1-weighted sequences and a patch-like signal with slightly higher intensity on T2 fat-suppressed sequences；the high T2 signal was seen in the synovial tissue， and the boundary was not clear. The preliminary consideration was left knee mass. The arthroscopic left knee joint lesion resection was performed； under the arthroscope， the appearance of the medial parapatellar synovium was basically normal，after removing the intimal layer of the superficial synovial tissue， the mass was located between the subintima of the synovium and the joint capsule， the mass was completely removed for submission， and the pathology results showed it was subsynovial hemangioma of the knee joint； the original pain in the left knee joint of the patient disappeared after operation. Conclusion Lots of patients with subsynovial hemangioma of the knee joint have medical history of trauma， manifesting as unexplained pain， swelling， and limited mobility of the knee joint； the diagnosis of the disease needs to be confirmed through the combination of imagological manifestations， arthroscope， and pathological examination results；the arthroscope surgery can significantly improve the prognosis of the patients， and it has some advantages，such as fewer surgical injuries， fewer postoperative complications， and faster recovery.

Key words: Arthroscopy, Subsynovial, Hemangioma, Knee joint, Case report