Summary

Compared to traditional open operation and traditional approach arthroscopic surgery resect the popliteal fossa cyst，double posteromedial approach has these advantages：Less trauma, excision completely, faster recovery, less complication, lower recurrence。

Abstract

Methods
• All the patients can be performed under lumbar anesthesia，and used
methylene blue(MB) to dye the cyst under the b-ultrasonic localization system。
• First，a routine anterolateral and anteromedial approach to establish before,
detect and process the articular cavity lesions. Then through the femoral condyle,
between the medial of PCL and the medial femoral condyle，arrive medial
compartment，to establish the first high-position medial approach under the
surveillance, and we can shave the joint capsule reflex .Expanding cyst opening。
• The valvular opening of the posterior capsule was enlarged with a shaver and
basket forceps to resect the capsular fold completely. When the cyst at the
posteromedial part of the skin was compressed by hand, a blue fluid was
observed gushing into the posteromedial compartment through the opening, and
we can see the whole cyst.
• Perfusion fluid filling, we can establish the second posterior medial approach; A
complete arthroscopic cystectomy was performed by shaving the inner wall of
the popliteal cyst.

Results

• Postoperative MRI showed that the cyst had disappeared, and No
complications such as the injury of blood vessel and nerve, or incision
infection occurred in all patients. All the patients were followed up,
No cyst reoccurred and the knee joint pain was relieved. According to
the criteria of Rauschning and Lindgren, there were 16 cases of grade
0, and 4 cases of grade I after operation, which was improved
obviously compared with that pre-operation.
Conclution:
• The described arthroscopic technique with additional posteromedial
cystic portal is effective for treating popliteal cysts, the advantage is
minimally invasive, quicker recovery, less influence to the function of
joint. We can effectively to remove the cyst sac and treat intraarticular
diseases simultaneously, shaving the cyst completely.