What is the procedure for excising a Baker's (popliteal) cyst in a patient who has failed conservative management?

Surgical Excision of Baker's Cyst

Surgical excision of a Baker's cyst should be reserved only for cases that have failed conservative management, including NSAIDs, intra-articular corticosteroid injection, and treatment of underlying intra-articular pathology—with arthroscopic evaluation and treatment of the underlying knee pathology being the preferred approach before considering cyst excision. 1, 2

When to Consider Surgical Excision

Surgical excision is indicated when:

• Conservative management (NSAIDs, physical therapy, activity modification) has been unsuccessful 1, 2
• Aspiration with or without corticosteroid injection has failed 1, 3
• Arthroscopic treatment of underlying intra-articular lesions (which are present in 61% of secondary Baker's cysts) has not resolved the cyst 4, 2
• The cyst causes arterial compression leading to lower limb ischemia or severe neurovascular compromise 5
• Mechanical symptoms persist despite appropriate treatment 2

Important caveat: Primary (congenital) Baker's cysts in children are self-limited and should be treated conservatively, not surgically 2. In adults, primary cysts may require excision, but secondary cysts (associated with intra-articular pathology) require addressing the underlying knee pathology first 4.

Surgical Technique

The procedure involves:

• Open surgical approach to the popliteal fossa with complete excision of the cyst 4
• The cyst is typically located between the medial head of gastrocnemius and semimembranosus tendon 6, 1
• Arthroscopic evaluation and treatment of any intra-articular lesions should be performed in conjunction with or prior to cyst excision 4, 2
• The communication between the cyst and joint space must be addressed 2

Surgical Outcomes

• Recurrence rates after surgical excision are low (2.5-5%) when performed appropriately 7
• Patient satisfaction is high: 61% rate results as "excellent" and 39% as "good" 4
• Full range of motion is typically restored 4
• Postoperative complications are uncommon but may include hematoma or effusion requiring reintervention 4

Critical Algorithm Before Surgery

Before proceeding to surgical excision, this stepwise approach must be followed:

1. Address underlying osteoarthritis with oral or topical NSAIDs (lowest effective dose) 1
2. Intra-articular corticosteroid injection into the knee joint to reduce inflammation and cyst size 1
3. Arthroscopic evaluation to identify and treat intra-articular lesions (meniscal tears, cartilage damage) 4, 2
4. Aspiration with corticosteroid injection of the cyst itself if symptoms persist 1, 3
5. Only after these measures fail should surgical excision be considered 2

Common pitfall: Performing cyst excision without addressing underlying intra-articular pathology leads to recurrence, as the cyst is typically secondary to knee joint disease 4, 2. Simple aspiration alone without sclerotherapy or corticosteroid injection invariably results in refilling and is not definitive therapy 1.