Arthroscopic cystectomy for Baker's cysts with and without one-way valve lesions: incidence of one-way valve lesion, associated pathologies, and clinical outcomes

Systematic review and meta-analysis of studies comparing cyst wall preservation against cyst wall resection during arthroscopic popliteal cyst decompression

INTRODUCTION

The optimal arthroscopic management for popliteal cyst decompression remains uncertain, with ongoing debate between preserving the cyst wall or completely removing it. The purpose of this study is to compare the outcomes and complications of arthroscopic popliteal cyst decompression with cyst wall preservation and cyst wall resection.

METHODS

A systematic review adhering to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines was conducted. It encompassed studies that focused on arthroscopic popliteal cyst decompression, considering both cyst wall preservation and cyst wall resection. The quality assessment of the included studies was carried out using the Methodology Index for Non-Randomized Research criteria. Following this, meta-analyses were conducted, employing odds ratios (ORs) for dichotomous outcomes and calculating mean differences (MDs) for continuous outcomes.

RESULTS

Four articles included a collective of 214 knees. Each of these studies presented level 3 evidence. The comparison between the cyst wall preservation group and the cyst wall resection group revealed similar clinical outcomes based on the Rauschning and Lindgren grade (grade 0 [OR = 0.66, 95% CI: 0.37-1.19, p = 0.17]; grade I [OR = 1.33, 95% CI: 0.66-2.67, p = 0.43]; grade II [OR = 1.39, 95% CI: 0.46-4.14, p = 0.56]; grade III [OR = 3.46, 95% CI: 0.13-89.95, p = 0.46]) and Lysholm score (MD = 0.83, 95% CI: -0.65-2.32, p = 0.27). However, MRI results indicated a significant improvement in the cyst wall resection group (cyst disappearance [OR = 0.50, 95% CI: 0.28-0.90, p = 0.02]; cyst shrinkage or decrease in size [OR = 1.41, 95% CI: 0.78-2.55, p = 0.26]; cyst persistence or recurrence [OR = 7.63, 95% CI: 1.29-45.08, p = 0.02]). Nevertheless, the operative time for cyst resection was significantly longer compared to cyst preservation (MD = -14.90, 95% CI: -21.96 - -7.84, p < 0.0001), and the cyst wall resection group experienced significantly higher complications than the cyst wall preservation group (OR = 0.24, 95% CI: 0.06 to 1.02, p = 0.05).

CONCLUSION

During arthroscopic popliteal cyst decompression, cyst wall resection led to longer operative times and higher complication rates but lower recurrence rates and better MRI outcomes. The functional outcomes after surgery were found to be similar.

Patient factors impacting localization of popliteal artery before total knee arthroplasty

PURPOSE

Intraoperative injury to the popliteal artery (PA) should be avoided during total knee arthroplasty (TKA). This study was performed to clarify the preoperative localization of the PA and the patient factors that impact its localization as a preventive measure.

METHODS

Ninety-seven patients (110 knees; 18 men, 79 women) with osteoarthritis who underwent primary TKA were retrospectively reviewed. Preoperative sagittal magnetic resonance imaging was used to measure the distance between the PA and the closest point at three levels: the femoral epicondyle (DPF), the tibial articular surface (DPAS), and the posterior tibial cortex (DPT). All variables are expressed in millimeters as median (interquartile range).

RESULTS

The median distance was 10.35 (7.90-12.34) mm for DPF, 6.32 (5.12-8.57) mm for DPAS, and 3.76 (2.28-5.26) mm for DPT. Body height and weight showed weak correlations with DPF (r = 0.324, p < 0.001 and r = 0.207, p = 0.03, respectively). DPF was smaller in women [9.82 (7.64-12.23) mm] than in men [11.27 (10.26-12.75) mm] (p = 0.004). A larger flexion angle and range of motion showed a weak negative correlation with DPT (r =  - 0.282, p = 0.003 and r =  - 0.236, p = 0.016, respectively). Multiple regression analysis revealed that DPF was related to body height (β = 0.341, p < 0.001) and that DPT was related to the flexion angle (β =  - 0.264, p = 0.005).

CONCLUSIONS

Special attention should be paid to women with a small physique on the femoral side and/or patients with a large flexion angle on the tibial side as a strategy to prevent PA-related complications.

Direct posterior endoscopic excision of atypical popliteal cyst: A case report

Certain types of popliteal cysts do not possess the common pathophysiology of Baker's cysts, such as location or the presence of a one-way valve lesion. The traditional arthroscopic approach and excision of such atypical popliteal cysts are difficult because they do not communicate with the knee joint, especially when located behind the popliteal neurovascular structure. In this case report, we introduce a direct posterior endoscopic technique for the excision of atypical popliteal cysts when accessing them through the traditional arthroscopic approach is unfeasible. In this case, the popliteal cyst was not located between the gastrocnemius medial head and the semimembranosus muscle and did not communicate with the knee joint. Passage of the popliteal artery was observed running on the anteromedial side of the popliteal cyst. Therefore, a direct posterior endoscopic approach was decided for the surgical treatment of the popliteal cyst, and the atypical popliteal cyst was successfully excised without any complications. We also describe the possible advantages and pitfalls of the direct posterior endoscopic approach.

Clinical relevance

Direct posterior endoscopic excision using an intra-cystic portal in the prone position is considered a safe and effective treatment method for atypical popliteal cysts.