Endoscopic Resection of Lateral Synovial Cyst of the Knee Tun Hing Lui, M.B.B.S.(HK), F.R.C.S.(Edin), F.H.K.A.M., F.H.K.C.O.S.
Abstract: Synovial cysts on the lateral side of the knee can cause pain, limitation of joint mobility, compression of the neighboring neurovascular structures, rupture leading to compartment syndrome, infection, erosion of adjacent bone, and iliotibial band friction syndrome. Open resection is commonly performed for symptomatic cysts. We describe an alternative, endoscopic approach to cyst resection. This has the advantages of minimally invasive surgery of smaller wounds, better cosmesis, and less surgical trauma.
C
ysts around the knee can be divided synovial cysts, bursae, ganglia, and meniscal cysts.1 Synovial cysts contain synovial fluid and are lined by a synovium-like membrane.2 Although the cysts connect to the joint space as a herniation of synovial tissue into the surrounding soft tissues, they can extend for a variable distance outside the joint space.1,2 The communication with the knee joint may not be identifiable.3 The cysts can occur because of traumatic, degenerative, or inflammatory conditions. Giant synovial cysts are typically due to rheumatoid arthritis; other causes include trauma and synovial pseudarthrosis.3 The cysts may cause pain, limitation of joint mobility, compression of the neighboring neurovascular structures, rupture leading to compartment syndrome, infection, erosion of adjacent bone, and iliotibial band friction syndrome.3-9 Open resection is commonly performed for symptomatic synovial cysts.3,5,8-12 Because of the strong association of intra-articular pathologies with these cysts, knee arthroscopy and treatment of the intra-articular pathologies have become trends and there has been an increase in surgeons’ interest in treating these cysts arthroscopically.5,13,14 Arthroscopic treatment is indicated when
From the Department of Orthopaedics and Traumatology, North District Hospital, Sheung Shui, China. The author reports that he has no conflicts of interest in the authorship and publication of this article. Received April 8, 2015; accepted August 4, 2015. Address correspondence to Tun Hing Lui, M.B.B.S.(HK), F.R.C.S.(Edin), F.H.K.A.M., F.H.K.C.O.S., Department of Orthopaedics and Traumatology, North District Hospital, 9 Po Kin Road, Sheung Shui, NT, Hong Kong SAR, China. E-mail: [email protected] Ó 2016 by the Arthroscopy Association of North America 2212-6287/15333/$36.00 http://dx.doi.org/10.1016/j.eats.2015.08.001
there is intra-articular communication and associated joint disorder because these lesions can be treated to obliterate the cysts and prevent their recurrence.3 We describe an endoscopic technique for resection of synovial cysts on the lateral side of the knee. It is indicated for symptomatic cysts without identifiable communication with the knee joint. It is also indicated for cysts associated with the proximal tibiofibular joint because the approach is essentially an endoscopic approach to the joint.14 Preoperative magnetic resonance imaging is an important investigation for preoperative planning because it provides information about the nature, dimension, and location of the cystic lesion and its relation with adjacent neurovascular structures (Fig 1).1,3,5,10,15
Technique
The patient is placed in the floppy lateral position so that the leg can be externally rotated to undergo knee arthroscopy and internally rotated to undergo endoscopic cyst resection. A thigh tourniquet is applied to provide a bloodless operative field. A 4.0-mm 30 arthroscope (Dyonics; Smith & Nephew Endoscopy, Andover, MA) is used. No arthroscopic pump is used. The portals for proximal tibiofibular arthroscopy are used for the endoscopic cyst resection. The proximal anterior portal is located at the intersection of the anterior border of the lateral collateral ligament and the projection line of the posterior border of the fibular head. The proximal posterior portal is located at the intersection of the anterior border of the biceps femoris tendon and the projection line of the anterior border of the fibular head (Fig 2).14 The length of the instrument to be inserted through the proximal anterior portal should be controlled so that it will not go beyond the
Arthroscopy Techniques, Vol 4, No 6 (December), 2015: pp e815-e818
e815
e816
T. H. LUI
Fig 1. Magnetic resonance images of a patient showing the anatomic location and dimensions of the cyst.
anterior border of the biceps femoris tendon. Doing so can avoid iatrogenic peroneal nerve injury. The knee is flexed during the procedure to relax the peroneal nerve and displace it posteriorly away from the operative field.14 The working area is the potential space deep to the lateral collateral ligament and anterior to the biceps femoris tendon. The instruments should be directed medially to reach the working space (Fig 3).14 The location of lateral synovial cysts of the knee can be classified into 3 zones: Zone 1 is posterior to the lateral collateral ligament, zone 2 is at the level of the lateral collateral ligament, and zone 3 is anterior to the lateral collateral ligament. A huge synovial cyst can span all 3 zones. The proximal anterior portal is the viewing portal and the proximal posterior portal is the instrumentation portal during debridement of zones 1 and 2. During endoscopic cyst resection in zone 1, the
popliteus tendon can be identified as it enters the knee joint and inserts into the lateral femoral condyle through an orifice at the posterolateral capsule (Fig 4). The stabilizing structures of the posterolateral complex including the popliteus tendon should be respected. During debridement of the posterolateral corner of the joint, the arthroscopic shaver (Smith & Nephew Endoscopy) opening should be facing anteriorly and debridement should be performed under arthroscopic visualization. Arthroscopic suction should be kept to a minimum to reduce the risk of injury to the peroneal nerve. In zone 2, the lateral collateral ligament and the biceps femoris tendon can be seen and should be respected (Fig 5). If debridement around the fibular head is needed, the anterior and posterior tibiofibular ligament should be preserved. After completion of debridement in zones 1 and 2, debridement of zone 3 is performed with the proximal anterior portal as the instrumentation portal and the proximal posterior portal as the viewing portal. Debridement of zone 3 can be extended to underneath the iliotibial band, and its insertion at the Gerdy tubercle should be respected. The capsular attachments of the lateral meniscus should be preserved during debridement of all 3 zones (Video 1). After resection of the cyst, knee arthroscopy is performed with the hip abducted and flexed. The knee joint is examined, and any concomitant intra-articular pathology is treated accordingly (Table 1).
Discussion Fig 2. Endoscopic resection of lateral synovial cyst in right knee. The patient is in the floppy lateral position with the leg internally rotated. The proximal anterior portal is located at the intersection of the anterior border of the lateral collateral ligament and the projection line of the posterior border of the fibular head. The proximal posterior portal is located at the intersection of the anterior border of the biceps femoris tendon and the projection line of the anterior border of the fibular head.
Arthroscopic treatment of a synovial cyst of the knee essentially entails intra-articular decompression of the cyst.2,6,10,16 It is believed that cyst formation depends on a connection between the joint and bursa, with a valve-like effect allowing the passage of fluid from the joint into the bursa with subsequent distention, producing these cysts.2 Intra-articular cyst decompression relies on resection of the connecting valvular mechanism. The procedure requires a bursal portal together
LATERAL SYNOVIAL CYST OF KNEE
e817
Fig 3. Endoscopic resection of lateral synovial cyst in right knee. The patient is in the floppy lateral position with the leg internally rotated. (A, B) The length of the instrument to be inserted through the proximal anterior portal should be controlled so that it will not go beyond the anterior border of the biceps femoris tendon. Doing so can avoid iatrogenic peroneal nerve injury. The knee is flexed during the procedure to relax the peroneal nerve and displace it posteriorly away from the operative field. The working area is the potential space deep to the lateral collateral ligament and anterior to the biceps femoris tendon. (C) The instruments should be directed medially to reach the working space.
with the knee arthroscopy portal.2,6,10,16 The arthroscopic approach is indicated if there is identifiable communication between the cyst and the knee and if safe establishment of the bursal portal is possible. The reported cases include cysts at the suprapatellar region or posteromedial knee. Establishing a posteromedial or suprapatellar bursal portal is safe because there are no adjacent major neurovascular structures. On the other hand, for posterolateral cysts, the establishment of the posterolateral bursal portal can injure the peroneal
nerve. Moreover, creation of a capsular defect at the posterolateral knee to resect the valvular mechanism will damage the posterolateral complex of the knee and result in knee instability. The reported endoscopic approach relies on the standard portal for endoscopy of the proximal tibiofibular joint. The lateral knee can be approached from zone 1 to zone 3. The communication between the cyst and the knee joint is easier identify endoscopically than arthroscopically because the capsule will not be obscured by
Fig 4. Endoscopic resection of lateral synovial cyst in right knee. The patient is in the floppy lateral position with the leg internally rotated. During arthroscopic debridement of zone 1, the popliteus tendon can be identified and should be respected.
Fig 5. Endoscopic resection of lateral synovial cyst in right knee. The patient is in the floppy lateral position with the leg internally rotated. During zone 2 debridement, the lateral collateral ligament can be seen and should be respected.
e818
T. H. LUI
Table 1. Pearls for Endoscopic Resection of Lateral Synovial Cysts of Knee Preoperative MRI is essential for surgical planning. The length of the instrument inserted through the proximal anterior portal should be controlled to avoid damage to the peroneal nerve. The working area is the potential space superior to the proximal tibiofibular joint and deep to the lateral collateral ligament. During debridement around the posterolateral corner of the knee in zone 1, the shaver opening should be facing anteriorly and suction should be kept to a minimum. Caution should be paid to avoid damage to the lateral knee capsule and the attachment of the lateral meniscus during debridement of the deep layer of the cyst wall. MRI, magnetic resonance imaging.
the lateral meniscus. Moreover, the proximal tibiofibular joint can be accessed, if indicated, through this approach. Any intra-articular pathology can be treated accordingly.14 The potential risks of the procedure include injury to the lateral collateral ligament, popliteal tendon, lateral capsule, and lateral meniscus. This procedure is technically demanding and should be reserved for experienced arthroscopists with a clear understanding of the anatomy of the knee. Because the lateral collateral ligament and the important posterolateral stabilizing structures of the knee can be accessed, the described endoscopic approach may form the basis for further development of arthroscopic reconstruction procedures for these capsuloligamentous structures. In conclusion, endoscopic resection of lateral synovial cysts of the knee is a feasible alternative to the classical open resection.
References 1. Telischak NA, Wu JS, Eisenberg RL. Cysts and cysticappearing lesions of the knee: A pictorial essay. Indian J Radiol Imaging 2014;24:182-191. 2. Shetty GM, Wang JH, Ahn JH, Lee YS, Kim BH, Kim JG. Giant synovial cyst of knee treated arthroscopically through a cystic portal. Knee Surg Sports Traumatol Arthrosc 2008;16:175-178. 3. Sinha K, Maheshwari R, Agrawal A. Giant synovial cyst of thigh: A rare entity. Case Rep Orthop 2013;2013:967215.
4. Al-Khateeb H, Ruiz A. Lateral meniscal cyst producing lesion of the tibial plateau and literature review. Int J Surg 2008;6:412-414. 5. Pecina HI, Boric I, Pecina TC, Smoljanovic T, Pecina M. Double synovial cyst of the proximal tibiofibular joint confirmed by MRI as a cause of the peroneal tunnel syndrome. Acta Chir Orthop Traumatol Cech 2008;75: 301-305. 6. He R, Guo L, Yang L, Chen GX, Duan XJ, Luo CF. Knee arthroscopic resection of articular capsule valvular treat popliteal cysts. Zhonghua Wai Ke Za Zhi 2013;51:417-420 [in Chinese]. 7. Costa ML, Marshall T, Donell ST, Phillips H. Knee synovial cyst presenting as iliotibial band friction syndrome. Knee 2004;11:247-248. 8. Niceforo A, Di Giunta ACC, Caminiti S, Tirrò S. A rare case of a large lateral meniscal cyst of the knee. Arthroscopy 1998;14:759-761. 9. Mortazavi SMJ, Farzan M, Asadollahi S. Proximal tibiofibular joint synovial cystdOne pathology with three different presentations. Knee Surg Sports Traumatol Arthrosc 2006;14:875-879. 10. Crnkovic T, Matijasevic B, Matokovic D. Large suprapatellar synovial cyst in a 12-year-old girl: Arthroscopic decompression. J Pediatr Orthop B 2010;19:114-117. 11. Shaikh N, Abdel-Galil K, Compson J. An unusual complication of knee arthroscopy: Portal site synovial cyst. Knee 2004;11:501-502. 12. Nakamae A, Deie M, Yasumoto M, Kobayashi K, Ochi M. Synovial cyst formation resulting from nonabsorbable meniscal repair devices for meniscal repair. Arthroscopy 2004;20:16-19 (suppl 1). 13. Choi EH, Huang J, Bryk D, Bryk E. Giant medial parameniscal cyst in an osteoarthritic knee. Orthopedics 2009;32. 14. Lui TH. Arthroscopic treatment of pigmented villonodular synovitis of the proximal tibiofibular joint. Knee Surg Sports Traumatol Arthrosc 2015;23:2278-2282. 15. McCarthy CL, McNally EG. The MRI appearance of cystic lesions around the knee. Skeletal Radiol 2004;33: 187-209. 16. Matokovic D, Haspl M, Drkulec V, Gotovac N, Cesarik M. Arthroscopic decompression of suprapatellar cyst: Case report. Knee Surg Sports Traumatol Arthrosc 2012;20:23252328.
Abstract: Synovial cysts on the lateral side of the knee can cause pain, limitation of joint mobility, compression of the neighboring neurovascular structures, rupture leading to compartment syndrome, infection, erosion of adjacent bone, and iliotibial band friction syndrome. Open resection is commonly performed for symptomatic cysts. We describe an alternative, endoscopic approach to cyst resection. This has the advantages of minimally invasive surgery of smaller wounds, better cosmesis, and less surgical trauma.
C
ysts around the knee can be divided synovial cysts, bursae, ganglia, and meniscal cysts.1 Synovial cysts contain synovial fluid and are lined by a synovium-like membrane.2 Although the cysts connect to the joint space as a herniation of synovial tissue into the surrounding soft tissues, they can extend for a variable distance outside the joint space.1,2 The communication with the knee joint may not be identifiable.3 The cysts can occur because of traumatic, degenerative, or inflammatory conditions. Giant synovial cysts are typically due to rheumatoid arthritis; other causes include trauma and synovial pseudarthrosis.3 The cysts may cause pain, limitation of joint mobility, compression of the neighboring neurovascular structures, rupture leading to compartment syndrome, infection, erosion of adjacent bone, and iliotibial band friction syndrome.3-9 Open resection is commonly performed for symptomatic synovial cysts.3,5,8-12 Because of the strong association of intra-articular pathologies with these cysts, knee arthroscopy and treatment of the intra-articular pathologies have become trends and there has been an increase in surgeons’ interest in treating these cysts arthroscopically.5,13,14 Arthroscopic treatment is indicated when
From the Department of Orthopaedics and Traumatology, North District Hospital, Sheung Shui, China. The author reports that he has no conflicts of interest in the authorship and publication of this article. Received April 8, 2015; accepted August 4, 2015. Address correspondence to Tun Hing Lui, M.B.B.S.(HK), F.R.C.S.(Edin), F.H.K.A.M., F.H.K.C.O.S., Department of Orthopaedics and Traumatology, North District Hospital, 9 Po Kin Road, Sheung Shui, NT, Hong Kong SAR, China. E-mail: [email protected] Ó 2016 by the Arthroscopy Association of North America 2212-6287/15333/$36.00 http://dx.doi.org/10.1016/j.eats.2015.08.001
there is intra-articular communication and associated joint disorder because these lesions can be treated to obliterate the cysts and prevent their recurrence.3 We describe an endoscopic technique for resection of synovial cysts on the lateral side of the knee. It is indicated for symptomatic cysts without identifiable communication with the knee joint. It is also indicated for cysts associated with the proximal tibiofibular joint because the approach is essentially an endoscopic approach to the joint.14 Preoperative magnetic resonance imaging is an important investigation for preoperative planning because it provides information about the nature, dimension, and location of the cystic lesion and its relation with adjacent neurovascular structures (Fig 1).1,3,5,10,15
Technique
The patient is placed in the floppy lateral position so that the leg can be externally rotated to undergo knee arthroscopy and internally rotated to undergo endoscopic cyst resection. A thigh tourniquet is applied to provide a bloodless operative field. A 4.0-mm 30 arthroscope (Dyonics; Smith & Nephew Endoscopy, Andover, MA) is used. No arthroscopic pump is used. The portals for proximal tibiofibular arthroscopy are used for the endoscopic cyst resection. The proximal anterior portal is located at the intersection of the anterior border of the lateral collateral ligament and the projection line of the posterior border of the fibular head. The proximal posterior portal is located at the intersection of the anterior border of the biceps femoris tendon and the projection line of the anterior border of the fibular head (Fig 2).14 The length of the instrument to be inserted through the proximal anterior portal should be controlled so that it will not go beyond the
Arthroscopy Techniques, Vol 4, No 6 (December), 2015: pp e815-e818
e815
e816
T. H. LUI
Fig 1. Magnetic resonance images of a patient showing the anatomic location and dimensions of the cyst.
anterior border of the biceps femoris tendon. Doing so can avoid iatrogenic peroneal nerve injury. The knee is flexed during the procedure to relax the peroneal nerve and displace it posteriorly away from the operative field.14 The working area is the potential space deep to the lateral collateral ligament and anterior to the biceps femoris tendon. The instruments should be directed medially to reach the working space (Fig 3).14 The location of lateral synovial cysts of the knee can be classified into 3 zones: Zone 1 is posterior to the lateral collateral ligament, zone 2 is at the level of the lateral collateral ligament, and zone 3 is anterior to the lateral collateral ligament. A huge synovial cyst can span all 3 zones. The proximal anterior portal is the viewing portal and the proximal posterior portal is the instrumentation portal during debridement of zones 1 and 2. During endoscopic cyst resection in zone 1, the
popliteus tendon can be identified as it enters the knee joint and inserts into the lateral femoral condyle through an orifice at the posterolateral capsule (Fig 4). The stabilizing structures of the posterolateral complex including the popliteus tendon should be respected. During debridement of the posterolateral corner of the joint, the arthroscopic shaver (Smith & Nephew Endoscopy) opening should be facing anteriorly and debridement should be performed under arthroscopic visualization. Arthroscopic suction should be kept to a minimum to reduce the risk of injury to the peroneal nerve. In zone 2, the lateral collateral ligament and the biceps femoris tendon can be seen and should be respected (Fig 5). If debridement around the fibular head is needed, the anterior and posterior tibiofibular ligament should be preserved. After completion of debridement in zones 1 and 2, debridement of zone 3 is performed with the proximal anterior portal as the instrumentation portal and the proximal posterior portal as the viewing portal. Debridement of zone 3 can be extended to underneath the iliotibial band, and its insertion at the Gerdy tubercle should be respected. The capsular attachments of the lateral meniscus should be preserved during debridement of all 3 zones (Video 1). After resection of the cyst, knee arthroscopy is performed with the hip abducted and flexed. The knee joint is examined, and any concomitant intra-articular pathology is treated accordingly (Table 1).
Discussion Fig 2. Endoscopic resection of lateral synovial cyst in right knee. The patient is in the floppy lateral position with the leg internally rotated. The proximal anterior portal is located at the intersection of the anterior border of the lateral collateral ligament and the projection line of the posterior border of the fibular head. The proximal posterior portal is located at the intersection of the anterior border of the biceps femoris tendon and the projection line of the anterior border of the fibular head.
Arthroscopic treatment of a synovial cyst of the knee essentially entails intra-articular decompression of the cyst.2,6,10,16 It is believed that cyst formation depends on a connection between the joint and bursa, with a valve-like effect allowing the passage of fluid from the joint into the bursa with subsequent distention, producing these cysts.2 Intra-articular cyst decompression relies on resection of the connecting valvular mechanism. The procedure requires a bursal portal together
LATERAL SYNOVIAL CYST OF KNEE
e817
Fig 3. Endoscopic resection of lateral synovial cyst in right knee. The patient is in the floppy lateral position with the leg internally rotated. (A, B) The length of the instrument to be inserted through the proximal anterior portal should be controlled so that it will not go beyond the anterior border of the biceps femoris tendon. Doing so can avoid iatrogenic peroneal nerve injury. The knee is flexed during the procedure to relax the peroneal nerve and displace it posteriorly away from the operative field. The working area is the potential space deep to the lateral collateral ligament and anterior to the biceps femoris tendon. (C) The instruments should be directed medially to reach the working space.
with the knee arthroscopy portal.2,6,10,16 The arthroscopic approach is indicated if there is identifiable communication between the cyst and the knee and if safe establishment of the bursal portal is possible. The reported cases include cysts at the suprapatellar region or posteromedial knee. Establishing a posteromedial or suprapatellar bursal portal is safe because there are no adjacent major neurovascular structures. On the other hand, for posterolateral cysts, the establishment of the posterolateral bursal portal can injure the peroneal
nerve. Moreover, creation of a capsular defect at the posterolateral knee to resect the valvular mechanism will damage the posterolateral complex of the knee and result in knee instability. The reported endoscopic approach relies on the standard portal for endoscopy of the proximal tibiofibular joint. The lateral knee can be approached from zone 1 to zone 3. The communication between the cyst and the knee joint is easier identify endoscopically than arthroscopically because the capsule will not be obscured by
Fig 4. Endoscopic resection of lateral synovial cyst in right knee. The patient is in the floppy lateral position with the leg internally rotated. During arthroscopic debridement of zone 1, the popliteus tendon can be identified and should be respected.
Fig 5. Endoscopic resection of lateral synovial cyst in right knee. The patient is in the floppy lateral position with the leg internally rotated. During zone 2 debridement, the lateral collateral ligament can be seen and should be respected.
e818
T. H. LUI
Table 1. Pearls for Endoscopic Resection of Lateral Synovial Cysts of Knee Preoperative MRI is essential for surgical planning. The length of the instrument inserted through the proximal anterior portal should be controlled to avoid damage to the peroneal nerve. The working area is the potential space superior to the proximal tibiofibular joint and deep to the lateral collateral ligament. During debridement around the posterolateral corner of the knee in zone 1, the shaver opening should be facing anteriorly and suction should be kept to a minimum. Caution should be paid to avoid damage to the lateral knee capsule and the attachment of the lateral meniscus during debridement of the deep layer of the cyst wall. MRI, magnetic resonance imaging.
the lateral meniscus. Moreover, the proximal tibiofibular joint can be accessed, if indicated, through this approach. Any intra-articular pathology can be treated accordingly.14 The potential risks of the procedure include injury to the lateral collateral ligament, popliteal tendon, lateral capsule, and lateral meniscus. This procedure is technically demanding and should be reserved for experienced arthroscopists with a clear understanding of the anatomy of the knee. Because the lateral collateral ligament and the important posterolateral stabilizing structures of the knee can be accessed, the described endoscopic approach may form the basis for further development of arthroscopic reconstruction procedures for these capsuloligamentous structures. In conclusion, endoscopic resection of lateral synovial cysts of the knee is a feasible alternative to the classical open resection.
References 1. Telischak NA, Wu JS, Eisenberg RL. Cysts and cysticappearing lesions of the knee: A pictorial essay. Indian J Radiol Imaging 2014;24:182-191. 2. Shetty GM, Wang JH, Ahn JH, Lee YS, Kim BH, Kim JG. Giant synovial cyst of knee treated arthroscopically through a cystic portal. Knee Surg Sports Traumatol Arthrosc 2008;16:175-178. 3. Sinha K, Maheshwari R, Agrawal A. Giant synovial cyst of thigh: A rare entity. Case Rep Orthop 2013;2013:967215.
4. Al-Khateeb H, Ruiz A. Lateral meniscal cyst producing lesion of the tibial plateau and literature review. Int J Surg 2008;6:412-414. 5. Pecina HI, Boric I, Pecina TC, Smoljanovic T, Pecina M. Double synovial cyst of the proximal tibiofibular joint confirmed by MRI as a cause of the peroneal tunnel syndrome. Acta Chir Orthop Traumatol Cech 2008;75: 301-305. 6. He R, Guo L, Yang L, Chen GX, Duan XJ, Luo CF. Knee arthroscopic resection of articular capsule valvular treat popliteal cysts. Zhonghua Wai Ke Za Zhi 2013;51:417-420 [in Chinese]. 7. Costa ML, Marshall T, Donell ST, Phillips H. Knee synovial cyst presenting as iliotibial band friction syndrome. Knee 2004;11:247-248. 8. Niceforo A, Di Giunta ACC, Caminiti S, Tirrò S. A rare case of a large lateral meniscal cyst of the knee. Arthroscopy 1998;14:759-761. 9. Mortazavi SMJ, Farzan M, Asadollahi S. Proximal tibiofibular joint synovial cystdOne pathology with three different presentations. Knee Surg Sports Traumatol Arthrosc 2006;14:875-879. 10. Crnkovic T, Matijasevic B, Matokovic D. Large suprapatellar synovial cyst in a 12-year-old girl: Arthroscopic decompression. J Pediatr Orthop B 2010;19:114-117. 11. Shaikh N, Abdel-Galil K, Compson J. An unusual complication of knee arthroscopy: Portal site synovial cyst. Knee 2004;11:501-502. 12. Nakamae A, Deie M, Yasumoto M, Kobayashi K, Ochi M. Synovial cyst formation resulting from nonabsorbable meniscal repair devices for meniscal repair. Arthroscopy 2004;20:16-19 (suppl 1). 13. Choi EH, Huang J, Bryk D, Bryk E. Giant medial parameniscal cyst in an osteoarthritic knee. Orthopedics 2009;32. 14. Lui TH. Arthroscopic treatment of pigmented villonodular synovitis of the proximal tibiofibular joint. Knee Surg Sports Traumatol Arthrosc 2015;23:2278-2282. 15. McCarthy CL, McNally EG. The MRI appearance of cystic lesions around the knee. Skeletal Radiol 2004;33: 187-209. 16. Matokovic D, Haspl M, Drkulec V, Gotovac N, Cesarik M. Arthroscopic decompression of suprapatellar cyst: Case report. Knee Surg Sports Traumatol Arthrosc 2012;20:23252328.
