Arthroscopic Treatment of Popliteal Cyst: A Direct Posterior Portal by Inside-Out Technique for Intracystic Debridement  Pinkawas Kongmalai, M.D., Bancha Chernchujit, M.D.  Arthroscopy Techniques  Volume 4, Issue 2, Pages e143-e148 (April 2015) DOI: 10.1016/j.eats.2014.12.002 Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 1 Aspiration of popliteal cyst fluid from left knee with 18-gauge needle. Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 2 The dye (methylene blue) is injected through the skin into the cyst. Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 3 Arthroscopic findings from the anterolateral portal in the left knee show the entry point for the arthroscope to the posteromedial compartment between the medial femoral condyle and posterior cruciate ligament. Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 4 Arthroscopic findings from the anterolateral portal in the left knee show the capsular fold located on the posteromedial side of the medial head of the gastrocnemius tendon. (The dotted lines represent the border of the capsular fold.) Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 5 Arthroscopic findings from the anterolateral portal in the left knee show partial resection of the posteromedial fold with a basket forceps through the posteromedial portal. Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 6 Arthroscopic findings from the anterolateral portal in the left knee show the fibrous membrane, nodules, and septa within the popliteal cyst, which may be factors associated with a postoperative recurrence after arthroscopic cystectomy. Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 7 Transillumination technique to avoid injury to popliteal vessels. The arrow indicates that the arthroscopic camera is within the cyst and close to the skin. Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 8 Inside-out technique to create direct posterior portal. One should note that the position of the direct posterior portal (white arrow) is separated from the posteromedial portal (black arrow). Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 9 Introduction of motorized shaver through direct posterior portal (arrow). The inset shows the motorized shaver through this portal, which facilitates intracystic debridement. Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 10 Flowchart for arthroscopic treatment of popliteal cyst. Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions

Fig 11 An axial-view magnetic resonance imaging scan of the left knee shows that the neurovascular structures are being pushed laterally by the popliteal cyst. The gray tube and blue arrow show the direction of the arthroscopic sheath and the Wissinger rod, which are distant from the neurovascular structures (red area). Arthroscopy Techniques 2015 4, e143-e148DOI: (10.1016/j.eats.2014.12.002) Copyright © 2015 Arthroscopy Association of North America Terms and Conditions