The diagnosis and therapy of synovial lipomatosis of the knee joint.

Abstract

Objective To investigate the denomination, diagnosis, and arthroscopic therapy of syn-ovial lipomatosis of knee joint. Methods Nine cases of synovial lipomatosis were retrospectively evaluated.There were 4 males and 5 females, with an average age of 51.1 years (range, 32-71 years). All patients were treated surgically, including 1 case of open surgery and 8 case of arthroscopy, with a mean follow-up of 18.2 months (range, 6-29 months). Under arthroscope, patellar bursa was occupied by light yellow, round and vil- lous processes in 4 cases, medial and lateral compartment were also involved. Synovial membrane manifested finger like clustery hyperplasia in 5 cases. MRI showed effusion of joint and tree like synovial mem-brane. Histology showed outer sphere of villi was formed with two or three layers of synovial cells, and inner part were filled with amount of mature iipocyte. The content of follow-up include: chief complaints, range of motion of knee joint and Lysholm score. Results No swollen nor effusion of the infected knee was found in all patients during the follow-up. Range of motion was 111.67°±11.18° at last follow-up. Lysholm scores was 72.44±13.93. The difference between results was statistically significant (t=3.447, 6.728, P=0.009, 0.001)compared with preoperative data 001.11°±16.54°, 40.56±19.93). Conclusion Synovial lipomatosis was usually misdiagnosed as synovial lipoma, and a thorough understanding of this disease is required. A clini-cal diagnosis comes from significant MRI manifestation, arthroscopic feature and histological finding. With the advantage of mini invasion and early recovery, arthroscopic cleaning is preferred to synovial lipomato-sis. Key words: Lipomatosis; Lipoma; Knee joint; Magnetic resonance imaging; Arthroscopy