Double posteromedial portal arthroscopy vs. other arthroscopic techniques for Baker's cyst: a systematic review and meta-analysis

Background Double posteromedial portal (DPP) arthroscopy has been proposed to improve cyst management in patients with Baker's cysts compared with other arthroscopic techniques. However, comparative evidence remains limited. Methods A systematic review and meta-analysis was conducted according to PRISMA guidelines. Comparative clinical studies assessing DPP vs. non-DPP arthroscopic techniques for Baker's cysts were identified from PubMed, Embase, Scopus, Web of Science Core Collection and the Cochrane Library. The primary outcome was cyst recurrence or residual cyst at final follow-up. Secondary outcomes included Lysholm score, operative time, and overall complications. Pooled risk ratios (RRs) or mean differences (MDs) were calculated using fixed- or random-effects models depending on heterogeneity (I²). Sensitivity analyses were performed to assess result robustness. Results Four comparative studies (all from China; total n = 232) were included. DPP arthroscopy showed a lower risk of cyst recurrence/residual cyst (RR = 0.17, 95% CI 0.04–0.74; RD = −0.08, 95% CI −0.14 to −0.02). Lysholm scores at final follow-up were similar between groups (MD = −0.65, 95% CI −2.14 to 0.84). Operative time was longer with DPP (MD = 13.20 min, 95% CI 6.16–20.24; I² = 91%), but remained longer after sensitivity analysis (MD = 10.02 min, 95% CI 7.09–12.96). Overall complications were higher with DPP (RR = 3.90, 95% CI 1.26–12.05; I² = 0%). Conclusion DPP arthroscopy may reduce cysts recurrence compared with other arthroscopic approaches, but at the cost of longer operative time and higher complication rates. Evidence is limited to small, single-country studies with sparse recurrence events; further multicentre trials are needed.