Popliteal Cyst in Children

Introduction

Common soft tissue mass in children
- most often not associated with meniscal tears
  - unlike in the adult population
Pathoanatomy
- popliteal cysts usually are located
  - between muscles of
    - semimembranosus
    - medial head of gastrocnemius
  - from herniated posterior knee joint capsule synovium

Anatomy

Muscles posterior to medial knee capsule
- semimembranosus
- medial head of gastrocnemius

Presentation

Symptoms
- usually asymptomatic
Physical exam
- located in popliteal fossa
  - usually located medially and distal to knee crease
    - most pronounced with knee extended
- mass will transilluminate

Imaging

Radiographs
- are normal
Ultrasound
- consistent with cystic lesion
MRI
- show fluid filled cyst

Treatment

Nonoperative
- observation
  - indications
    - mainstay of treatment
      - with majority of cases resolving spontaneously
Operative
- excision
  - indications
    - only if cyst causes significant discomfort
    - failure of spontaneous resolution

TAG

(OBQ05.44) A 10-year-old boy presents with a mobile, soft, and painless mass over the posteromedial aspect of his knee. MRI demonstrates a simple cyst. What is the most appropriate next step in treatment? Topic

Review Topic

1. CT with intravenous contrast
2. Bone scan
3. Radical excision
4. Arthroscopic resection
5. Observation

PREFERRED RESPONSE ▶

DISCUSSION: The description of the mass (soft and non-tender, in the posterior knee) in a young patient suggests that this is a popliteal, or Baker’s, cyst. The article by Dinham reviewed the natural history of 120 cases of popliteal cysts in children and reported that, of seventy untreated cysts, fifty-one disappeared spontaneously during a mean period of one year and eight months. The article also noted that those cysts which fail to regress spontaneously may respond to aspiration, but have a high recurrence rate. Given the lack of symptoms and the likelihood of resolution, observation is the first-line treatment for most popliteal cysts.

REFERENCES:

1. Dinham JM. Popliteal cysts in children: The case against surgery. JBJS Br: 1975 (57); pp 69-71. PMID:1117024 (Link to Abstract)

Question Authors:

Greg Galano MD, Patrick McCulloch MD, Eric Shirley MD,

Please Rate Educational Value!

3.0

Average 3.0 of 10 Ratings

Textbooks

Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012
AAOS Comprehensive Orthopaedic Review, Jay R. Leiberman. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2009
Orthopaedic Knowledge Update 10, John M Flyn. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2011
Hoppenfeld SP. Surgical Exposures in Orthopaedics: The Anatomic Approach. Lipponcott, Williams, and Wilkins, Philadelphia, PA, Copyright 2009
Orthopaedic In-training Examination (OITE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012
Self-Assessment Examination (SAE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012

Undefined

Dinham JM. Popliteal cysts in children: The case against surgery. JBJS Br: 1975 (57); pp 69-71. PMID:1117024 (Link to Abstract)

Qbank (1 Questions)

Question Comments

Videos

Groups

Evidence & References Show References

Topic Comments