Arthroscopic Procedure for Baker's Cyst Release: Step-by-Step Technique
The arthroscopic procedure for Baker's cyst release involves creating a connection between the joint and cyst followed by removal of the cyst's inner wall through multiple portals, with mandatory treatment of any associated intra-articular pathology.1
Preoperative Assessment
- Baker's cysts are related to increased intra-articular pressure caused by inflammatory, degenerative, or traumatic disorders 1
- Preoperative evaluation should include sonography and X-ray of the knee to differentiate between primary (congenital) and secondary forms (associated with intra-articular lesions) 2
- MRI may be necessary in some cases for better visualization of the cyst and associated pathologies 3
Anesthesia and Setup
- Procedure is performed under general, regional (spinal/epidural), or local anesthesia 4
- Patient is positioned for standard knee arthroscopy with access to the posterior aspect of the knee 1
- Standard arthroscopic equipment including camera, shaver, and specialized instruments are required 4
Surgical Technique
Step 1: Initial Arthroscopy and Portal Placement
- Create standard anterolateral portal for the arthroscope 1
- Perform diagnostic arthroscopy to identify and document any intra-articular pathology 2
- Advance the arthroscope through the intercondylar notch, below the posterior cruciate ligament, to the posteromedial recess 1
Step 2: Posteromedial Portal Creation
- Under direct visualization with the arthroscope, create a posteromedial portal 1
- This portal will be used as a working portal for initial cyst decompression 1
Step 3: Identification and Resection of Capsular Fold
- Identify the capsular fold (valvular mechanism) that separates the cyst from the joint cavity 1
- Using a shaver through the posteromedial portal, resect this fold until a large enough connection exists between the joint and the cyst 1
- This step is critical for cyst decompression and preventing recurrence 1, 5
Step 4: Direct Cyst Visualization
- After decompression, insert the arthroscope from the posteromedial portal directly into the cyst cavity 1
- Create an additional far posterior cystic portal for working instruments 1
Step 5: Cyst Wall Removal
- Through the far posterior cystic portal, use a shaver to remove the inner wall of the cyst 1
- Thorough removal of the cyst lining is essential to prevent recurrence 5
Step 6: Treatment of Associated Intra-articular Pathology
- It is mandatory to treat any associated intra-articular pathological condition 1
- This may include partial meniscectomy, debridement of degenerative changes, or other procedures as indicated 1, 2
- Failure to address the underlying knee pathology significantly increases the risk of cyst recurrence 3
Step 7: Closure and Post-operative Care
- Close portal incisions with standard technique 4
- Apply sterile dressings and compression bandage 4
- Recovery typically takes between 2 to 6 weeks 4
- Patients are usually unable to bear full weight for 2-7 days after surgery 4
Alternative Techniques
- All-inside arthroscopic suture technique: An alternative approach involving suturing the gateway to the gastrocnemius-semimembranosus bursa through anterolateral viewing and posteromedial working portals 5
- This technique has shown 96% clinical improvement with 64% complete cyst disappearance and 27% reduction in cyst size on MRI at 2-year follow-up 5
Potential Complications and Considerations
- Possible complications include hematoma, effusion, infection, and cyst recurrence 2, 3
- Recurrence is more likely in patients with chronic knee joint disease with effusions or recurrent hydrarthrosis 3
- Primary forms of Baker's cyst should always be extirpated based on clinical experience 2