Highlights & Basics
- Popliteal cyst, an accumulation of synovial fluid, is common. It is usually the result of a knee joint abnormality such as arthritis or a cartilage tear.
- May present with swelling or pain behind the knee, but most cases are asymptomatic.
- May rupture, leading to severe pain and calf swelling.
- Usually only conservative treatment is required.
- Large symptomatic cysts that do not resolve may require drainage or surgical excision.
Quick Reference
History & Exam
Key Factors
Other Factors
Diagnostics Tests
Treatment Options
Definition
Epidemiology
Etiology
Pathophysiology
Images
Popliteal cyst
Anatomical dissection of the posteromedial knee capsule. The weak area (A) is identified between the 2 expansions of the semimembranosus muscle (B), the oblique popliteal ligament (C), and the expansion over the sheath of the popliteus muscle (D). The semitendinosus muscle (E) and popliteus muscle (F) are also indicated
A ruptured hemorrhagic popliteal cyst extending in the calf
Synovitis within cyst
MRI depicting cyst in interval of medial gastrocnemius and semimembranosus
Interval of medial gastrocnemius and semimembranosus viewed with arthroscope
Preoperative T2-weighted MRI showing posterior fluid collection communicating with posterior medial joint in a patient with a popliteal cyst secondary to pigmented villonodular synovitis
Muscles surrounding the popliteal fossa (view of posterior aspect of right knee)
Popliteal cyst lying in its most common location in the posteromedial popliteal fossa (A), dissecting through the deep fascia (B) and the medial head of the gastrocnemius muscle (C)
Deep dissection of the posteromedial capsule. The 2 expansions of the semimembranosus muscle have been elevated, exposing the weak area of the capsule between the posterior cruciate ligament (A) and the posterior horn of the medial meniscus (B) that gives entry to the knee joint. The medial femoral condyle is also visible (C)
Arthroscopic resection of a popliteal cyst
Arthroscopic resection of a popliteal cyst
Septae within a popliteal cyst
Ruptured popliteal cyst dissection into gastrocnemius
Citations
Labropoulos N, Shifrin DA, Paxinos O. New insights into the development of popliteal cysts. Br J Surg. 2004;91:1313-1318.[Abstract]
Chatzopoulos D, Moralidis E, Markou P, et al. Baker's cysts in knees with chronic osteoarthritic pain: a clinical, ultrasonographic, radiographic and scintigraphic evaluation. Rheumatol Int. 2008 Dec;29(2):141-6.[Abstract]
American College of Radiology. ACR appropriateness criteria: chronic knee pain. 2018 [internet publication].[Full Text]
1. Labropoulos N, Shifrin DA, Paxinos O. New insights into the development of popliteal cysts. Br J Surg. 2004;91:1313-1318.[Abstract]
2. Miller TT, Staron RB, Koenigsberg T, et al. MR imaging of Baker cysts: association with internal derangement, effusion, and degenerative arthropathy. Radiology. 1996 Oct;201(1):247-50.[Abstract]
3. Volteas SK, Labropoulos N, Leon M, et al. Incidence of ruptured Baker's cyst among patients with symptoms of deep vein thrombosis. Br J Surg. 1997 Mar;84(3):342.[Abstract]
4. Langsfeld M, Matteson B, Johnson W, et al. Baker's cysts mimicking the symptoms of deep vein thrombosis: diagnosis with venous duplex scanning. J Vasc Surg. 1997 Apr;25(4):658-62.[Abstract]
5. Sansone V, De Ponti A. Arthroscopic treatment of popliteal cyst and associated intra-articular knee disorders in adults. Arthroscopy. 1999 May;15(4):368-72.[Abstract]
6. Andonopoulos AP, Yarmenitis S, Sfountouris H, et al. Baker's cyst in rheumatoid arthritis: an ultrasonographic study with a high resolution technique. Clin Exp Rheumatol. 1995 Sep-Oct;13(5):633-6.[Abstract]
7. Chatzopoulos D, Moralidis E, Markou P, et al. Baker's cysts in knees with chronic osteoarthritic pain: a clinical, ultrasonographic, radiographic and scintigraphic evaluation. Rheumatol Int. 2008 Dec;29(2):141-6.[Abstract]
8. Picerno V, Filippou G, Bertoldi I, et al. Prevalence of Baker's cyst in patients with knee pain: an ultrasonographic study. Reumatismo. 2014 Mar 14;65(6):264-70.[Abstract][Full Text]
9. Handy JR. Popliteal cysts in adults: a review. Semin Arthritis Rheum. 2001 Oct;31(2):108-18.[Abstract]
10. Stone KR, Stoller D, De Carli A, et al. The frequency of Baker's cysts associated with meniscal tears. Am J Sports Med. 1996 Sep-Oct;24(5):670-1.[Abstract]
11. Rupp S, Seil R, Jochum P, et al. Popliteal cysts in adults. Prevalence, associated intraarticular lesions, and results after arthroscopic treatment. Am J Sports Med. 2002 Jan-Feb;30(1):112-5.[Abstract]
12. Kulshrestha A, Misra RN, Agarwal P, et al. Magnetic resonance appearance of tuberculosis of the knee joint with ruptured Baker's cyst. Australas Radiol. 1995 Feb;39(1):80-3.[Abstract]
13. Wascher DC, Hartman GP, Salka C, et al. Coccidiomycosis presenting as a popliteal cyst. Arthroscopy. 1998 Jan-Feb;14(1):99-102.[Abstract]
14. Cuende E, Barbadillo C, E-Mazzucchelli R, et al. Candida arthritis in adult patients who are not intravenous drug addicts: report of three cases and review of the literature. Semin Arthritis Rheum. 1993 Feb;22(4):224-41.[Abstract]
15. Blanco R, Gonzalez-Gay MA, Varela J, et al. Baker's cyst as a clinical presentation of brucellosis. Clin Infect Dis. 1996 May;22(5):872-3.[Abstract]
16. Tosti R, Kelly JD 4th. Pigmented villonodular synovitis presenting as a baker cyst. Am J Orthop (Belle Mead NJ). 2011 Oct;40(10):528-31.[Abstract]
17. Simkin PA. Physiology of normal and abnormal synovium. Semin Arthritis Rheum. 1991;21:179-83.[Abstract]
18. Ahlqvist J. Rheumatoid factors and physiology of synovial joints. Scand J Rheumatol Suppl. 1988;75:278-283.[Abstract]
19. American College of Radiology. ACR appropriateness criteria: chronic knee pain. 2018 [internet publication].[Full Text]
20. Liu K, Li X, Weng Q, et al. Diagnostic accuracy of ultrasound for the assessment of Baker's cysts: a meta-analysis. J Orthop Surg Res. 2022 Dec 12;17(1):535.[Abstract][Full Text]
21. Frush TJ, Noyes FR. Baker's cyst: diagnostic and surgical considerations. Sports Health. 2015 Jul;7(4):359-65.[Abstract]
22. Raghupathi AK, Shetty A. Unusual presentation of popliteal soft tissue sarcoma: not every swelling in the knee is a Baker's cyst. J Surg Case Rep. 2013 Oct 4;2013(10):rjt074.[Abstract][Full Text]
23. Smith MK, Lesniak B, Baraga MG, et al. Treatment of popliteal (Baker) cysts with ultrasound-guided aspiration, fenestration, and injection: long-term follow-up. Sports Health. 2015;7:409-414.[Abstract]
24. Zhou XN, Li B, Wang JS, et al. Surgical treatment of popliteal cyst: a systematic review and meta-analysis. J Orthop Surg Res. 2016;11:22.[Abstract][Full Text]
25. Ahn JH, Lee SH, Yoo JC, et al. Arthroscopic treatment of popliteal cysts: clinical and magnetic resonance imaging results. Arthroscopy. 2010;26:1340-1347.[Abstract]
26. Yang B, Wang F, Lou Y, et al. A comparison of clinical efficacy between different surgical approaches for popliteal cyst. J Orthop Surg Res. 2017 Oct 25;12(1):158.[Abstract][Full Text]
27. Fukumoto K, Kojima T, Tomonari H, et al. Ethanol injection sclerotherapy for Baker's cyst, thyroglossal duct cyst, and branchial cleft cyst. Ann Plast Surg. 1994;33:615-9.[Abstract]
28. Centeno CJ, Schultz J, Freeman M. Sclerotherapy of Baker's cyst with imaging confirmation of resolution. Pain Physician. 2008;11:257-61.[Abstract][Full Text]
29. Dinham JM. Popliteal cysts in children. The case against surgery. J Bone Joint Surg Br. 1975;57-B:69-71.[Abstract][Full Text]
30. Burt TB, MacCarter DK, Gelman MI, et al. Clinical manifestations of synovial cysts. West J Med. 1980 Aug;133(2):99-104.[Abstract][Full Text]
31. Petros DP, Hanley JF, Gilbreath P, et al. Posterior compartment syndrome following ruptured Baker's cyst. Ann Rheum Dis. 1990 Nov;49(11):944-5.[Abstract][Full Text]
32. Schimizzi AL, Jamali AA, Herbst KD, et al. Acute compartment syndrome due to ruptured Baker cyst after nonsurgical management of an anterior cruciate ligament tear: a case report. Am J Sports Med. 2006 Apr;34(4):657-60.[Abstract]
33. Papadopoulos A, Karachalios TS, Malizos CN, et al. Complicated septic arthritis after knee arthroscopy in a 75-year-old man with osteoarthritis and a popliteal cyst. BMJ Case Rep. 2015 Apr 9;2015.[Abstract][Full Text]
