Use of a Cutting Instrument for Fresh Osteochondral Distal Tibia Allograft Preparation: Treatment of Glenoid Bone Loss  Marcio B. Ferrari, M.D., Anthony Sanchez, B.S., George Sanchez, B.S., Ramesses Akamefula, B.S., Bradley M. Kruckeberg, B.A., Matthew T. Provencher, M.D.  Arthroscopy Techniques  Volume 6, Issue 2, Pages e363-e368 (April 2017) DOI: 10.1016/j.eats.2016.10.010 Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 1 To prepare the distal tibia allograft, an Arthrex workstation (Arthrex, Naples, FL) is used. This device provides a safe and reliable method for firm positioning through the use of a triangular base that is placed inside the bone medullary cavity. (A) Two spiked lateral fixation arms (red arrows) are used to stabilize the graft at the supramalleolar level, adding more stability to the graft. (B) The anterior arm (orange arrow) is added perpendicularly to the 2 spiked lateral fixation arms, as it will serve as the cutting guide holder. Arthroscopy Techniques 2017 6, e363-e368DOI: (10.1016/j.eats.2016.10.010) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 2 The distal tibia allograft must be placed with the cartilaginous surface facing up and the tibial shaft perpendicular to the table to avoid errors while cutting. Once the graft is in the correct position, 2 spiked lateral fixation arms must be adjusted to the metaphysis at the supramalleolar level. Two K-wires (red arrows) are then passed through the tibial shaft to keep the graft firmly in place. Arthroscopy Techniques 2017 6, e363-e368DOI: (10.1016/j.eats.2016.10.010) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 3 (A) The first cutting guide (orange arrow) is positioned parallel to the graft's cartilaginous surface. (B) With the use of an oscillating saw and the first cutting guide, the graft is cut in the 2 available slots (red dotted lines). Of note, it is important that the assistant provide irrigation with saline solution during cutting to keep the bone and cartilage cool, thereby avoiding damage to the graft. These first cuts will establish the length of the graft. Arthroscopy Techniques 2017 6, e363-e368DOI: (10.1016/j.eats.2016.10.010) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 4 The allograft is positioned with the cartilaginous surface facing up. (A) After the first cuts are made, the first cutting guide is released and the second cutting guide (red arrow) is positioned above the cartilaginous surface with the use of the anterior arm. (B) This guide is divided into 2 parts (orange arrows) that remain in a vertical position with the surface of the topmost part at the same level as the cartilaginous surface of the graft. Once this position is confirmed, the cuts can be performed. This cut will define the width of the graft. Arthroscopy Techniques 2017 6, e363-e368DOI: (10.1016/j.eats.2016.10.010) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 5 (A) The edge and the medial aspect of the graft must be marked with a surgical pen to outline the cuts. (B) A guide is then placed in contact with the cartilaginous area to be used to introduce 2 K-wires (red arrows) into the graft. This guide will later be used to transport the graft to provide optimal positioning of the graft onto the glenoid neck. Arthroscopy Techniques 2017 6, e363-e368DOI: (10.1016/j.eats.2016.10.010) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 6 To perform the third cut in the distal tibia allograft, the 2 K-wires are removed and the anterior arm is used to hold the third cutting guide (red arrow). The guide should be in direct contact with the medial malleolus and parallel to the cartilaginous surface. As in all the other cuts, saline solution must be provided to avoid damage to the graft. Arthroscopy Techniques 2017 6, e363-e368DOI: (10.1016/j.eats.2016.10.010) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions

Fig 7 (A) After completion of all cuts, the graft (red arrow) is free and ready to be transported onto the glenoid neck. (B) The same device (red arrow) used to insert the K-wires into the graft is then used to transport the graft onto the glenoid neck. (C) The device extends (red arrow) just above the cartilaginous surface of the graft to ensure optimal positioning and facilitate leveling with the native glenoid. Arthroscopy Techniques 2017 6, e363-e368DOI: (10.1016/j.eats.2016.10.010) Copyright © 2016 Arthroscopy Association of North America Terms and Conditions