Knee Surgery, Sports Traumatology, Arthroscopy

, Volume 22, Issue 2, pp 247–262 | Cite as

‘The Sneaky Plica’ revisited: morphology, pathophysiology and treatment of synovial plicae of the knee

  • Oliver S. SchindlerEmail author



To comprise current knowledge on morphology, embryology and pathophysiology of synovial plicae as well as on clinical and therapeutic aspects of the plica syndrome.


Review of the literature combined with a meta-analysis of studies assessing the outcome of open or arthroscopic plica excision including the author’s own series.


The term synovial plica has been devised to describe a number of intra-capsular folds thought to represent remnants of a membranous knee joint partition present during foetal development. Although four such folds have been defined, it is mainly the medial patellar plica which is implicated in carrying clinical significance as a potential cause of anteromedial knee pain particularly in adolescents. Blunt trauma, a sudden increase in athletic activity or any form of transient synovitis are associated with plica inflammation leading to tissue fibrosis and subsequent loss of elasticity. A plica affected in this way may impinge against intra-articular structures in its proximity, often creating localised chondromalacia particularly of the patello-femoral joint. The diagnosis is based on history and clinical examination although MRI can be of value. Twenty-three studies assessing the clinical out-come of 969 patients following open or arthroscopic plica excision were identified. The average age was 25 years with equal male-to-female ratio. Trauma was considered the cause in 57 %. At a mean follow-up of 27.5 months, 64 % of patients were symptom free, 26 % improved and 10 % considered failures.


Symptomatic plicae may initially be treated with physiotherapeutic measures and structured exercise regimes but success rates are generally low. Intra-plical or intra-articular corticosteriod injections may be beneficial if administered early in the disease process. Arthroscopic excision of the entire plical fold becomes indicated in recalcitrant cases and once a plica has undergone irrevocable morphological changes. The procedure carries low morbidity, and results are universally good especially if the plica is the sole pathology. Factors associated with a favourable outcome are young patient age, localised symptoms of short duration and absence of plica induced chondromalacia.

Level of evidence

Level IV.


Synovial plica Anterior knee pain Fold Shelf Septum Ligamentum mucosum Knee 



The author conveys his appreciation and gratitude to all patients who participated in the presented study. A special thank you is extended to Lesley Greig and the library staff of the Learning & Teaching Centre at Southmead Hospital in Bristol/UK and to Sylvia Louise Davies.


  1. 1.
    Ackroyd CE (2011) Personal communicationGoogle Scholar
  2. 2.
    Anderson H (1950) Histochemical studies on the histogenesis of the knee and superior tibio fibular joints. Am J Anat 86:235–287CrossRefGoogle Scholar
  3. 3.
    Aprin H, Shapiro J, Gershwind M (1984) Arthrography (plica views): a non-invasive method for diagnosis and prognosis of plica syndrome. Clin Orthop Relat Res 183:90–95PubMedGoogle Scholar
  4. 4.
    Amatuzzi MM, Fazzi A, Varella MH (1990) Pathologic synovial plica of the knee. Results of conservative treatment. Am J Sports Med 18:466–469PubMedCrossRefGoogle Scholar
  5. 5.
    Amatuzzi MM, Albuquerque RF (1994) Pathologic synovial plica of the knee. Results of surgical treatment in 37 knees [In Portugese]. Rev Hosp Clin Fac Med Sao Paulo 49:104–106PubMedGoogle Scholar
  6. 6.
    Baker W (1875) On the ligamentum mucosum. Proc Royal Ir Acad Sci 2:193–201Google Scholar
  7. 7.
    Barber FA (1987) Fenestrated medial patella plica. Arthroscopy 3:253–257PubMedCrossRefGoogle Scholar
  8. 8.
    Bick EM (1930) Surgical pathology of synovial tissue. J Bone Joint Surg 12:33–44Google Scholar
  9. 9.
    Blackburn TA Jr, Eiland WG, Bandy WG (1982) An introduction to the plica. J Orthop Sports Phys Ther 3:171–177PubMedCrossRefGoogle Scholar
  10. 10.
    Bough BW, Regan BF (1985) Medial and lateral synovial plicae of the knee: pathological significance diagnosis and treatment by arthroscopic surgery. Ir Med J 78:279–282PubMedGoogle Scholar
  11. 11.
    Boven F, De Boeck M, Potvliege R (1983) Synovial plicae of the knee on computed tomography. Radiology 147:805–809PubMedGoogle Scholar
  12. 12.
    Brief LP, Laico JP (1987) The superolateral approach: a better view of the medial patellar plica. Arthroscopy 3:170–172PubMedCrossRefGoogle Scholar
  13. 13.
    Broom MJ, Fulkerson JP (1986) The plica syndrome: a new perspective. Orthop Clin North Am 17:279–281PubMedGoogle Scholar
  14. 14.
    Broukhim B, Fox JM, Blazina ME, Del Pizzo W, Hirsh L (1979) The synovial shelf syndrome. Clin Orthop Relat Res 142:135–138PubMedGoogle Scholar
  15. 15.
    Calpur OU, Copuroglu C, Ozcan M (2002) United unresorbed medial and lateral plicae as anterior mesenchymal synovial septal remnant. Knee Surg Sports Traumatol Arthrosc 10:378–380PubMedCrossRefGoogle Scholar
  16. 16.
    Cella JP, Salvati EA, Sculco TP (1988) Indomethacin for the prevention of heterotopic ossification following total hip arthroplasty: effectiveness, contraindications and adverse effects. J Arthroplast 3:229–234CrossRefGoogle Scholar
  17. 17.
    Christoforakis JJ, Sanchez-Ballester J, Hunt N, Thomas R, Strachan RK (2006) Synovial shelves of the knee: association with chondral lesions. Knee Surg Sports Traumatol Arthrosc 14:1292–1298PubMedCrossRefGoogle Scholar
  18. 18.
    Dandy DJ (1986) Arthroscopy in the treatment of young patients with anterior knee pain. Orthop Clin North Am 17:221–229PubMedGoogle Scholar
  19. 19.
    Dandy DJ (1987) Arthroscopic Management of the Knee. Churchill Livingstone, EdinburghGoogle Scholar
  20. 20.
    Dandy DJ (1990) Anatomy of the medial suprapatellar plica and medial synovial shelf. Arthroscopy 6:79–85PubMedCrossRefGoogle Scholar
  21. 21.
    Dandy DJ (2012) Personal communicationGoogle Scholar
  22. 22.
    Demirag B, Ozturk C, Karakayali M (2006) Symptomatic infrapatellar plica. Knee Surg Sports Traumatol Arthrosc 14:156–160PubMedCrossRefGoogle Scholar
  23. 23.
    Derks WH, De Hooge P, Van Linge B (1986) Ultrasonographic detection of the patellar plica in the knee. J Clin Ultrasound 14:355–360PubMedCrossRefGoogle Scholar
  24. 24.
    Deutsch AL, Resnick D, Dalinca MK, Gilula L, Danzig L, Guerra J Jr, Dunn FH (1981) Synovial plicae of the knee. Diagn Radiol 141:627–634Google Scholar
  25. 25.
    DiStefano V, Nixon JE (1972) Steroid-induced skin changes following local injection. Clin Orthop Relat Res 87:254–256PubMedCrossRefGoogle Scholar
  26. 26.
    Dorchak JD, Barrack RL, Kneisl JS, Alexander AH (1991) Arthroscopic treatment of symptomatic synovial plica of the knee: long-term follow-up. Am J Sports Med 19:503–507PubMedCrossRefGoogle Scholar
  27. 27.
    Dye SF, Vaupel GL, Dye CC (1998) Conscious neurosensory mapping of the internal structures of the human knee without intraarticular anaesthesia. Am J Sports Med 26:773–777PubMedGoogle Scholar
  28. 28.
    Ewing JW (1993) Plica: pathologic or not? J Am Acad Orthop Surg 1:117–121PubMedGoogle Scholar
  29. 29.
    Fick R (1911) Handbuch der Anatomie und Mechanik der Gelenke. 3 Teil: Spezielle Gelenk- und Muskelmechanik. Gustav Fischer, JenaGoogle Scholar
  30. 30.
    Flanagan JP, Trakru S, Meyer M, Mullaji AB, Krappel F (1994) Arthroscopic excision of symptomatic medial plica: a study of 118 knees with 1–4 year follow-up. Acta Orthop Scand 65:408–411PubMedCrossRefGoogle Scholar
  31. 31.
    Fulkerson JP, Hungerford DS (1990) Surgical treatment of patellofemoral chondrosis and arthrosis. In: Fulkerson JP, Hungerford DS. Disorders of the patellofemoral joint. 2nd Ed, Williams & Wilkins, Baltimore pp 226–246Google Scholar
  32. 32.
    Fulkerson JP (1991) Discussion. Am J Sports Med 19:507CrossRefGoogle Scholar
  33. 33.
    Gandolfi M, Morselli R, Pegreffi P, Armaroli D (1982) Sindrome della plica sinoviale clinica diagnosi terapia [In Italien]. Chir Organi Mov 68:603–613PubMedGoogle Scholar
  34. 34.
    García-Valtuille R, Abascal F, Cerezal L, García-Valtuille A, Pereda T, Canga A, Cruz A (2002) Anatomy and MR imaging appearances of synovial plicae of the knee. Radiographics 22:775–784PubMedCrossRefGoogle Scholar
  35. 35.
    Gray DJ, Gardner E (1950) Prenatal development of the human knee and superior tibiofibular joints. Am J Anat 86:235–287PubMedCrossRefGoogle Scholar
  36. 36.
    Griffith CJ, LaPrade RF (2008) Medial plica irritation: diagnosis and treatment. Curr Rev Musculoskelet Med 1:53–60PubMedCentralPubMedCrossRefGoogle Scholar
  37. 37.
    Hansen H, Boe S (1989) The pathological plica in the knee: results after arthroscopic resection. Arch Orthop Trauma Surg 108:282–284PubMedCrossRefGoogle Scholar
  38. 38.
    Hardaker WT, Whipple TL, Bassett FH (1980) Diagnosis and treatment of the plica syndrome of the knee. J Bone Joint Surg Am 62-A:221–225Google Scholar
  39. 39.
    Harrewyn JM, Aignan M, Delbarre F (1982) Les brides synovialis du genou [In French]. Rev du Rhumatisme 49:3–9Google Scholar
  40. 40.
    Harty M, Joyce JJ III (1977) Synovial folds in the knee joint. Orthop Rev 7:91–92Google Scholar
  41. 41.
    Henke JW (1863) Handbuch der Anatomie und Mechanik der Gelenke mit Rücksicht auf Luxationen und Contracturen [In German]. CF Winter’sche Verlagshandlung, Leipzig & HeidelbergGoogle Scholar
  42. 42.
    Hohlbaum J (1923) Die Bursa suprapatellaris und Ihre Beziehungen zum Kniegelenk. Ein Beitrag zur Entwicklung der angeborenen Schleimbeutel [In German]. Bruns Beitr Klin Chir 128:481–489Google Scholar
  43. 43.
    Hughston JC, Whatley GS, Dodelin RA, Stone MM (1963) The role of the suprapatellar plica in internal derangement of the knee. Am J Orthop 5:25–27PubMedGoogle Scholar
  44. 44.
    Hughston JC, Stone M, Andrews JR (1973) The suprapatellar plica: its role in internal derangement of the knee. J Bone Joint Surg Am 55-A:1318Google Scholar
  45. 45.
    Insall J (1982) Current concepts review: patellar pain. J Bone Joint Surg Am 64:147–152PubMedGoogle Scholar
  46. 46.
    Jackson RW (1980) The sneaky plicae (editorial). J Rheumatol 7:437PubMedGoogle Scholar
  47. 47.
    Jackson RW, Marshall DJ, Fujisawa Y (1982) The pathological medial shelf. Orthop Clin North Am 13:307–312PubMedGoogle Scholar
  48. 48.
    Johnson DP, Eastwood DM, Witherow PJ (1993) Symptomatic synovial plicae of the knee. J Bone Joint Surg 75-A:1485–1496Google Scholar
  49. 49.
    Joyce JJ, Harty M (1984) Surgery of the synovial fold. In: Cassells W (ed) Arthroscopy diagnosis and surgical practice. Lea & Febinger, Philadelphia pp 201-209Google Scholar
  50. 50.
    Kim S-J, Lee D-H, T-E Kim (2007) The relationship between the MPP test and arthroscopically found medial patellar plica pathology. Arthroscopy 23:1303–1308PubMedCrossRefGoogle Scholar
  51. 51.
    Kinnard P, Levesque RY (1984) The plica syndrome: a syndrome of controversy. Clin Orthop Relat Res 183:141–143PubMedGoogle Scholar
  52. 52.
    Klein W (1983) The medial shelf of the knee: a follow up study. Arch Orthop Trauma Surg 102:67–72PubMedCrossRefGoogle Scholar
  53. 53.
    Koshino T, Okamoto R (1985) Resection of painful shelf under arthroscopy. Arthroscopy 1:136–141PubMedCrossRefGoogle Scholar
  54. 54.
    Kurosaka M, Yoshia S, Yamada M, Hirohata K (1992) Lateral synovial plica syndrome. a case report. Am J Sports Med 20:92–94PubMedCrossRefGoogle Scholar
  55. 55.
    Limbird TJ (1988) Patellar subluxation following plica resection. Orthop Rev 17:282–285PubMedGoogle Scholar
  56. 56.
    Lino S (1939) Normal arthroscopic findings of the knee joint in adult cadavers [In Japanese]. J Jpn Orthop Assoc 14:467–523Google Scholar
  57. 57.
    Lupi L, Bighi S, Cervi PM, Limone GL, Massari L (1990) Arthrography of the plica syndrome and its significance. Eur J Radiol 11:15–18PubMedCrossRefGoogle Scholar
  58. 58.
    Mayeda T (1918) Über das strangartige Gebilde in der Kniegelenkhöhle [In German]. Mitteilungen der Medizinischen Fakultät der Kaiserlichen Universität Tokyo 21:507–553Google Scholar
  59. 59.
    Merchant AC (2001) Patellofemoral joint disorders. In: Chapman MW (ed). Chapman’s Orthopaedic Surgery. Lippincott Williams & Wilkins, Philadelphia pp 2321-2337Google Scholar
  60. 60.
    Mink JH, Reicher MA, Crues III Jr (1987) Magnetic resonance imaging of the knee. Raven Press, New YorkGoogle Scholar
  61. 61.
    Mital MA, Hayden J (1979) Pain in the knee in children: the medial plica shelf syndrome. Orthop Clin North Am 10:713–722PubMedGoogle Scholar
  62. 62.
    Mizumachi S, Kawakashima W, Okamura T (1948) So called synovial shelf in the knee joint [In Japanese]. J Jap Orthop Assoc 22:1–5Google Scholar
  63. 63.
    Møller H (1981) Incarcerating mediopatellar synovial plica syndrome. Acta Orthop Scand 52:357–361PubMedCrossRefGoogle Scholar
  64. 64.
    Munzinger U, Ruckstuhl J, Scherrer H, Gschwend N (1981) Internal derangement of the knee joint due to pathologic synovial folds: the mediopatellar plica syndrome. Clin Orthop Relat Res 155:59–64PubMedGoogle Scholar
  65. 65.
    Muse GL, Grana WA, Hollingsworth S (1985) Arthroscopic treatment of medial shelf syndrome. Arthroscopy 1:63–67PubMedCrossRefGoogle Scholar
  66. 66.
    Nakanishi K, Inoue M, Ishida T, Murakami T, Tsuda K, Ikezoe J, Nakamura H (1996) MR evaluation of mediopatellar plica. Acta Radiol 37:567–571PubMedCrossRefGoogle Scholar
  67. 67.
    Nakayama A, Sugita T, Aizawa T, Takahshi A, Honma T (2011) Incidence of medial plica in 3,889 knee joints in the Japanese population. Arthroscopy 11:1523–1527CrossRefGoogle Scholar
  68. 68.
    Newman RJ (1984) Local skin depigmentation due to corticosteroid injection. BMJ 288:1725–1726PubMedCrossRefGoogle Scholar
  69. 69.
    Nickerson SH (1945) Pathology of anomalies found in knee joints. Am J Radiol 53:213–229Google Scholar
  70. 70.
    Nottage WM, Sprague NF, Auerbach BJ, Shahriaree H (1983) The medial patellar plica syndrome. Am J Sports Med 11:211–214PubMedCrossRefGoogle Scholar
  71. 71.
    O’Dwyer KJ, Peace PK (1988) The plica syndrome. Injury 19:350–352PubMedCrossRefGoogle Scholar
  72. 72.
    Ogata S, Uhthoff HK (1990) The development of synovial plicae in human knee joints: an embryologic study. Arthroscopy 6:315–321PubMedCrossRefGoogle Scholar
  73. 73.
    Patel D (1978) Arthroscopy of the plicae: synovial folds and their significance. Am J Sports Med 6:217–225PubMedCrossRefGoogle Scholar
  74. 74.
    Patel D (1986) Plica as a cause of anterior knee pain. Orthop Clin North Am 17:273–277PubMedGoogle Scholar
  75. 75.
    Patel D, Laurencin CT, Tsuchiya A, Dutka M (1993) Synovial Folds – Plicae. In: Fox JM, DelPizzo W (eds) The Patellofemoral Joint, 1st edn. McGraw Hill, NewYork, pp 193–198Google Scholar
  76. 76.
    Pipkin G (1950) Lesions of the suprapatellar plica. J Bone Joint Surg Am 32-A:363–369Google Scholar
  77. 77.
    Pipkin G (1971) Knee injuries: the role of the suprapatellar plica and suprapatellar bursa in simulating internal derangements. Clin Orthop Relat Res 74:161–176PubMedCrossRefGoogle Scholar
  78. 78.
    Reider B, Marshall JL, Warren RF (1981) Persistent vertical septum in the human knee joint. J Bone Joint Surg Am 63:1185–1187PubMedGoogle Scholar
  79. 79.
    Richmond JC, McGinty JB (1983) Segmental arthroscopic resection of the hypertrophic mediopatellar plica. Clin Orthop Relat Res 178:185–189PubMedGoogle Scholar
  80. 80.
    Rovere GD, Adair DM (1985) Medial synovial shelf plica syndrome: treatment by intraplical steroid injection. Am J Sports Med 13:382–385PubMedCrossRefGoogle Scholar
  81. 81.
    Rue J-PH, Ferry AT, Bach BR (2008) Plica excision: revisited. Tech Knee Surg 7:1–3Google Scholar
  82. 82.
    Sakakibara JO (1976) Arthroscopic study on Iino’s band. J Jpn Orthop Assoc 50:513–522Google Scholar
  83. 83.
    Schindler OS (2004) Synovial plicae of the knee. Curr Orthop 18:210–219CrossRefGoogle Scholar
  84. 84.
    Schonholtz GJ, Magee CM (1986) The synovial plicae of the knee joint. Contemp Orthop 12:31–37Google Scholar
  85. 85.
    Schulitz KP, Hille E, Kochs W (1983) The importance of the mediopatellar synovial plica for chondromalacia patellae. Arch Orthop Trauma Surg 102:37–44PubMedCrossRefGoogle Scholar
  86. 86.
    Shetman D, Hamorick GW Jr, Wilson CE (1963) Cutaneous changes following local injection of triamcinolone. Arch Dermatol 88:820–828CrossRefGoogle Scholar
  87. 87.
    Strover AE, Rouholamin E, Guirgis N, Behdad H (1991) An arthroscopic technique of demonstrating the pathomechanics of the suprapatellar plica. Arthroscopy 7:308–310PubMedCrossRefGoogle Scholar
  88. 88.
    Theut PC, Fulkrson JP (2003) Anterior knee pain and patellar subluxation. In: DeLee JC, Drez D, Miller MD (eds) Orthopaedic Sports Medicine, 2nd edn. Saunders, Philadelphia, pp 1829–1831Google Scholar
  89. 89.
    Tifford CD, Jackson DW (2003) Surgical management of the pathological plica. In: Jackson DW (ed). Master Techniques in Orthopaedic Surgery: Reconstructive Knee Surgery, 2nd ed, Lippincott Williams & Wilkins, Philadelphia pp 441–445Google Scholar
  90. 90.
    Vaubel E (1938) Die Arthroskopie (Endoskopie des Kniegelenks). Steinkopff, Dresden & LeipzigGoogle Scholar
  91. 91.
    Vaughan-Lane T, Dandy DJ (1982) The synovial shelf syndrome. J Bone Joint Surg [Br] 64-B:475–476Google Scholar
  92. 92.
    Verdonk R, Rombouts J, Van Vynckt C, Uyttendaele D, Claessens H (1982) Medial plica synovialis or shelf syndrome of the knee. Acta Orthop Belg 48:463–467PubMedGoogle Scholar
  93. 93.
    Wachtler F (1979) Die plica synovialis infrapatellaris beim Menschen [In German]. Acta Anat 104:451–459PubMedCrossRefGoogle Scholar
  94. 94.
    Weckström M, Niva MH, Lamminen A, Mattila VM, Philajamäki HK (2010) Arthroscopic resection of medial plica of the knee in young adults. Knee 17:103–107PubMedCrossRefGoogle Scholar
  95. 95.
    Yilmaz C, Golpinar A, Vucuru A, Ozturk H, Eskandari MM (2005) Retinacular band excision improves outcome in treatment of plica syndrome. Int Orthop 29:291–295PubMedCentralPubMedCrossRefGoogle Scholar
  96. 96.
    Zanoli S, Piazzai E (1983) The synovial plica syndrome of the knee: pathology, differential diagnosis and treatment. It J Orthop Trauma 9:241–250Google Scholar

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© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Bristol Arthritis and Sports Injury ClinicSt Mary’s HospitalBristolUK

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