Endoscopic Fusion of the Accessory Navicular Synchondrosis That Has No Diastasis  Tun Hing Lui, M.B.B.S.(HK), F.R.C.S.(Edin), F.H.K.A.M., F.H.K.C.O.S.  Arthroscopy Techniques  Volume 6, Issue 2, Pages e263-e267 (April 2017) DOI: 10.1016/j.eats.2016.09.029 Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 1 Endoscopic fusion of the left accessory navicular synchondrosis that has no diastasis. The patient is in the supine position with the legs spread. The surface landmarks of tibialis posterior tendon (TPT), navicular bone (N), accessory navicular bone (AN), and the synchondrosis (S) are outlined. The dorsal portal (DP) and plantar portal (PP) are located at the dorsal and plantar ends of the accessory navicular synchondrosis, respectively. (MM, medial malleolus.) Arthroscopy Techniques 2017 6, e263-e267DOI: (10.1016/j.eats.2016.09.029) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 2 Endoscopic fusion of the left accessory navicular synchondrosis that has no diastasis. The patient is in the supine position with the legs spread. (A) The accessory navicular synchondrosis (S) is identified under fluoroscopy, and a needle is inserted into the synchondrosis. (B) This needle (Ne) serves as a landmark of the S during the endoscopy. The plantar portal (PP) is the viewing portal, and the needle is identified. The surface of the synchondrosis around the needle is debrided with an arthroscopic shaver (AS) via the dorsal portal (DP). (AN, accessory navicular bone; MM, medial malleolus; N, navicular bone; TPT, tibialis posterior tendon.) Arthroscopy Techniques 2017 6, e263-e267DOI: (10.1016/j.eats.2016.09.029) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 3 Endoscopic fusion of the left accessory navicular synchondrosis that has no diastasis. The patient is in the supine position with the legs spread. The plantar portal is the viewing portal. The dorsal part of the synchondrosis (S) is cut open by a serrated banana knife (K) via the dorsal portal. (AN, accessory navicular bone; N, navicular bone.) Arthroscopy Techniques 2017 6, e263-e267DOI: (10.1016/j.eats.2016.09.029) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 4 Endoscopic fusion of the left accessory navicular synchondrosis that has no diastasis. The patient is in the supine position with the legs spread. The plantar portal is the viewing portal. The synchondrosis is debrided by an arthroscopic shaver (AS) via the dorsal portal. (AN, accessory navicular bone; N, navicular bone.) Arthroscopy Techniques 2017 6, e263-e267DOI: (10.1016/j.eats.2016.09.029) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 5 Endoscopic fusion of the left accessory navicular synchondrosis that has no diastasis. The patient is in the supine position with the legs spread. The plantar portal is the viewing portal. The fusion surface of the accessory navicular bone (AN) is microfractured by an arthroscopic awl (AA). The fusion surface of the navicular bone (N) has already been drilled with a K wire. Arthroscopy Techniques 2017 6, e263-e267DOI: (10.1016/j.eats.2016.09.029) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 6 Endoscopic fusion of the left accessory navicular synchondrosis that has no diastasis. The patient is in the supine position with the legs spread. (A) The synchondrosis is reduced under fluoroscopy. A guide wire is inserted across the synchondrosis, and a headless screw is inserted along the guide wire. (B) Postoperative radiograph shows that the synchondrosis is well fixed by a headless screw. (AN, accessory navicular bone; N, navicular bone; S, accessory navicular synchondrosis.) Arthroscopy Techniques 2017 6, e263-e267DOI: (10.1016/j.eats.2016.09.029) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions