What is the recommended operating room (OR) technique for excision of a symptomatic Baker's cyst in a patient who has not responded to conservative management?

Operating Room Technique for Excision of Baker's Cyst

For symptomatic Baker's cysts that have failed conservative management, surgical excision should be performed via a posterior approach with the patient in prone position, utilizing direct visualization to completely excise the cyst at its neck where it communicates with the knee joint, followed by closure of the joint capsule defect.

Patient Selection for Surgical Excision

Surgical excision is reserved as a last-resort intervention after failure of conservative management, which should include NSAIDs, compression, and appropriate exercises 1, 2. The decision to proceed with surgery should be made when:

• Persistent mechanical symptoms continue despite 3-6 months of conservative therapy 1
• The cyst causes significant functional impairment or vascular compromise 3
• Recurrent symptomatic cysts occur after aspiration attempts 2

Arthroscopic evaluation of the knee joint must be performed prior to or concurrent with cyst excision to identify and treat any underlying intra-articular pathology, as associated intra-articular lesions are very common with popliteal cysts and failure to address these leads to recurrence 1, 4.

Surgical Technique

Patient Positioning and Approach

• Position the patient prone on the operating table to provide optimal access to the popliteal fossa 4
• Make a transverse or S-shaped incision over the popliteal fossa, centered over the palpable cyst 4
• Carefully dissect through subcutaneous tissue, identifying and protecting the medial sural cutaneous nerve and small saphenous vein 4

Cyst Dissection and Excision

• Identify the cyst between the medial head of gastrocnemius and semimembranosus tendon, which is the typical anatomic location 1, 4
• Dissect the cyst completely down to its neck where it communicates with the posterior joint capsule - this is the critical step to prevent recurrence 4
• Excise the cyst at its base, ensuring complete removal of the cyst wall 4
• Close the defect in the joint capsule with interrupted absorbable sutures to prevent reformation of the cyst 4

Concurrent Arthroscopic Management

• Perform arthroscopy through standard anterior portals either before or after cyst excision 1, 4
• Address any intra-articular pathology identified (meniscal tears, cartilage lesions, synovitis) as these are present in the majority of cases and contribute to cyst formation 1, 4
• Failure to treat underlying intra-articular disease is associated with higher recurrence rates 4

Critical Technical Pitfalls to Avoid

• Incomplete excision of the cyst neck is the most common cause of recurrence - the communication with the joint capsule must be identified and closed 4
• Simple aspiration or incision without complete excision leads to high recurrence rates and should be avoided 2
• Failure to perform arthroscopy and address intra-articular pathology in secondary cysts (61% of cases) results in persistent symptoms 4
• Injury to neurovascular structures in the popliteal fossa, particularly the tibial nerve and popliteal vessels, requires meticulous dissection technique 4

Postoperative Management

• Early range of motion exercises should begin within 48-72 hours to prevent stiffness 2
• Weight-bearing as tolerated with crutches for comfort during the first 1-2 weeks 2
• Monitor for complications including hematoma formation (which may require drainage) and wound effusion 4

Expected Outcomes

Surgical excision with proper technique achieves excellent results in 61% and good results in 39% of patients, with full range of motion restoration and recurrence rates of only 5% when the cyst neck is properly addressed and intra-articular pathology is treated 4.