Tibial tunnel and pretibial cysts following ACL graft reconstruction: MR imaging diagnosis.
Tunnel cyst formation is a rare complication after anterior cruciate ligament reconstruction, usually occurring 1-5 years post-operatively, which may occasionally be symptomatic. There are multiple proposed theories regarding the etiology of tunnel cysts. Theories include necrosis, foreign-body reaction, lack of complete graft osteo-integration, and intravasation of articular fluid. It is important to know if the tunnel cysts are communicating or not communicating with the joint, as surgical management may be different. Imaging characteristics on magnetic resonance images (MRI) include tibial tunnel widening, multilocular or unilocular cyst formation in the graft or tibial tunnel, with possible extension into the pretibial space, intercondylar notch, and/or popliteal fossa. The MR imaging differential diagnosis of tibial tunnel cysts includes infection, foreign-body granuloma, or tibial screw extrusion. Importantly, to the best of our knowledge, graft failure or instability has not been reported in association with tibial tunnel cysts.
Musculoskeletal Imaging and Intervention, Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA. varandg@gmail.com
Varand
V
Ghazikhanian
Javier
J
Beltran
Violeta
V
Nikac
Marina
M
Feldman
Jenny T
JT
Bencardino
D059549:Anterior Cruciate Ligament Reconstruction; D001845:Bone Cysts / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011183:Postoperative Complications / Q000175:diagnosis*; D013977:Tibia