[Comparison of therapeutic effects of arthroscopic popliteal cyst internal drainage and capsular wall resection]

To investigate efficacy between arthroscopic popliteal cyst drainage and arthroscopic popliteal cyst resection.

From January 2013 to June 2021, 54 patients with popliteal cyst (Rausching-Lindgren gradeⅠto Ⅲ) were treated with arthroscopic surgery. There were 24 males and 30 females. The age ranged from 44 to 72 years old, with a mean of (62.67±6.08) years old. The course of the disease ranged from 1 to 72 months, with a mean of(15±14) months. Twenty-four patients (group A) were underwent arthroscopic internal drainage of popliteal cyst. Thirty patients (group B) were underwent arthroscopic resection of popliteal cyst. Preoperative main symptoms included knee pain, swelling, walking pain, popliteal swelling, popliteal mass and so on. After 1, 3, 6 months and 1, 2 years of surgery, routine outpatient follow-up was conducted to observe and compare the surgical time, bleeding volume, preoperative and postoperative visual analog scale (VAS), knee Lysholm score, and complications between two groups.

All incisions healed at one stage after operation. All 54 patients were followed up, and the duration ranged from 6 months to 2 years, with an average of (13.89±4.29) months. There was no intraoperative vascular or nerve injury. Operation time and intraoperative blood loss of the two groups:group A of (62.08±9.55) min and (8.00±1.69) ml, group B of (69.50±6.99) min and (8.70±2.00) ml. Popliteal pain, swelling, limitation of flexion and extension were significantly relieved after operation. VAS before and one month after operation between two groups:group A of 5.38±1.21 and 2.63±0.71, group B of 5.60±1.26 and 2.80±0.81. Lysholm scores of knee joint before and 6 months after operation:group A of 62.59±4.99 and 89.74±2.90, group B of 63.87±3.23 and 89.02±2.35. Knee joint function improved significantly in both groups. In group A, 4 cases had popliteal cyst at 3 months after operation, and 2 cases had small isolated cyst at 1 year after operation. There was no recurrence of cyst in group B.

The results between two arthroscopic treatments of popliteal cyst are satisfactory, and there is no significant difference in the amount of blood loss, safety, postoperative pain VAS score and knee function recovery. It is suggested that arthroscopic resection of the cyst wall should be performed when the technique is mature, especially for large cysts and septal cysts.