Arthroscopic all-inside suture of symptomatic Baker's cysts: a technical option for surgical treatment in adults

Synovial fluid caused by repeated effusions may replete the gastrocnemius-semimembranosus bursa (GSB) communicating with the knee joint. Fluid trapped inside the GSB through an alleged unidirectional valve-like mechanism forms a so-called Baker's cyst. Since a significant association of Baker's cysts with knee joint disorders has been reported, treatment should primarily address articular lesions causing recurrent effusions. Arthroscopic surgery provides an effective treatment in that both the cyst and associated joint disorders can be optimally visualized and accordingly treated. In the present paper an all-inside arthroscopic technique for suturing the gateway to the GSB through an anterolateral viewing portal and a posteromedial working portal is proposed. The rationale underlying this technique is that no conclusive evidences exist that the one-way valve-like mechanism is purely anatomical. A retrospective study was conducted on 22 patients (9 males and 13 females, mean age 56 +/- 10 SD years) affected by a symptomatic Baker's cyst associated to knee joint disorders. Pre- and post-operative evaluation at 2 year follow-up consisted of clinical assessment by Rauschning and Lindgren criteria and magnetic resonance imaging (MRI). The results showed that 96% of patients showed clinical improvement. Baker's cyst disappeared in 64% of patients, reduced in 27% and persisted in 9% on MRI. All patients with cyst reduction exhibited clinical amelioration. Our results suggest the all-inside arthroscopic suture technique would improve Baker's cyst-related symptoms by either disappearance or reduction of the cyst. We believe the availability of multiple arthroscopic techniques to treat symptomatic Baker's cysts could broaden the therapeutic armamentarium of knee arthroscopists.