1. The document describes a technique for using the reamer irrigator aspirator (RIA) to harvest autogenous bone graft from the tibia for use in tibiotalocalcaneal (TTC) arthrodesis performed with a retrograde intramedullary nail. 2. The RIA technique reams the tibial medullary canal while continuously irrigating and aspirating marrow and bone into a collection canister, providing a large amount of autogenous graft without requiring an additional incision or donor site. 3. Potential advantages of this technique include obtaining significant bone graft without an extra incision, but concerns include the risk of tibial stress fractures from reaming and increased knee

1. AUTOGENOUS BONE GRAFT HARVEST USING REAMER IRRIGATOR ASPIRATOR (RIA) TECHNIQUE FOR TIBIOTALOCALCANEAL ARTHRODESIS Daniel J. Cuttica, DO, J. George DeVries, DPM, Christopher F. Hyer, DPM, FACFAS ORTHOPEDIC FOOT & ANKLE CENTER | Columbus, OH | 614-895-8747 | www.orthofootankle.com REFERENCES: 1. Kile TA, Donnelly RE, et al. Tibiotalocalcaneal arthrodesis with an intramedullary device. Foot Ankle Int 1994; 15:669-673. 2. Quill GE. Tibiotalocalcaneal Arthrodesis With Medullary Rod Fixation. Tech Foot Ankle Surg 2003;2:135-143. 3. Mendicino RW, Catanzariti AR, Saltrick KR, et al. Tibiotalocalcaneal arthrodesis with retrograde intramedullary nailing. J Foot Ankle Surg 43; 2004:82-86. 4. Hammett R, Hepple S, et al. Tibiotalocalcaneal (hindfoot) arthrodesis by retrograde intramedullary nailing usinf a curved locking nail. The results of 52 procedures. Foot Ankle Int 2005; 26:810-815. 5. Younger EM, Chapman MW. Morbidity at Bone Graft Donor Sites. J Orthop Trauma . 1989; 3:192-195. DISCUSSION: TTC arthrodesis is a demanding procedure, with a significant reported rate of nonunion 1-4 . The RIA technique has been shown to be a tool to obtain autogenous bone graft with some advantages over other methods, including less donor site morbidity than that reported for ICBG 7-9 . Obtaining bone graft from the tibia during a TTC fusion treated via an IM nail may represent an ideal situation, as no further incisions are required, it provides a method to achieve significant amounts of bone graft without the need for an additional donor site, and it involves a bone that necessitates reaming for the index procedure. However, there are concerns and questions regarding this technique. There have been reports of stress fractures with standard hindfoot arthrodesis nails 4 , but what effect the reaming of the entire canal will have on the incidence of stress fractures remains to be seen. Another concern is that of donor site morbidity. The incidence of knee pain after this technique has not been elucidated, and its increase over standard TTC arthrodeses with a retrograde IM nail is something that must be addressed and explored. Finally, concern has been raised over the necessity of bone graft elsewhere as many surgeons advocate resection and milling of the fibula to act as autogenous bone graft. However, IM bone graft from the RIA reamer has several advantages over the fibula resection. The fibula is largely cortical bone at the ankle, and this is not as rich in osteoinductive and osteoconductive cells as compared to intramedullary and metaphyseal bone 6 . Also, it may be more cosmetically preferable to preserve the fibula if possible. CONCLUSION: The RIA technique as a method to achieve autogenous bone graft for TTC arthrodesis via a retrograde IM nail is a novel technique described here. With no additional incisions or violation of additional bones, intramedullary bone can be harvested as bone graft to augment fusion. However, there are concerns over possible complications related to this technique. Further studies are needed to quantify the specific clinical augmentation rates, and to explore possible future indications and usage. INTRODUCTION: Use of an intramedullary (IM) nail for tibiotalocalcaneal (TTC) arthrodesis has the advantages of providing rigid fixation, compression, and load-sharing capability 1,2 . Despite these advantages, complications such as nonunion and delayed union still exist 1-4 . Bone grafting is commonly employed in arthrodesis procedures to decrease the risk of nonunion. Autogenous iliac crest has long been the gold standard. However, concerns over donor site morbidity continue to exist 5 . A more recent technique of obtaining autogenous bone graft is the use of the reamer-irrigator-aspirator (RIA) technique. This method was designed to irrigate and aspirate the contents of the medullary canal as a single-pass reamer. Continuous irrigation allows for cooling of the reamer to prevent heat necrosis of the bone, while the aspiration and removal of marrow and bone decreases the intramedullary pressures. A large amount of autogenous bone graft can be obtained with this technique, without the donor site morbidity typically seen from iliac crest harvesting. Here, we describe a new technique to obtain autogenous bone graft for use in TTC arthrodesis treated via a retrograde intramedullary nail using the RIA technique. SURGICAL TECHNIQUE: The patient is placed in the supine position with a bolster under the hip of the affected extremity for improved lateral exposure. An extensile lateral incision is made, beginning proximal to the distal tip of the fibula and extending to the base of the fourth metatarsal. The fibula is exposed, osteotomized, and retracted or resected. Next, the ankle and subtalar joints are exposed, the joint surfaces are prepared for arthrodesis, and the foot and ankle are reduced to a position of neutral dorsiflexion, 5 degrees of valgus, and rotation with the 2nd toe in line with the tibial crest. Preparation for IM nail insertion is then performed, by drilling the guidewire, overdrilling, and sequentially reaming in 0.5-1 mm increments in a retrograde manner. The smallest sized reamer in the RIA system is 12 mm, so reaming up to 11 mm or 11.5 mm prior to use of the RIA reamer is typically performed. Next, with an assistant maintaining the foot in proper position, the guidewire for the nail is removed and a new ball-tipped guidewire from the RIA system is placed. The RIA reamer is placed over the guidewire and the irrigation clamp is opened to ensure adequate flow of irrigation fluid. The reamer is advanced over the guidewire, into the calcaneus and reaming is begun. A flow of blood and bone marrow should then become visible in the tubes into the suction canister. Reaming is performed gradually, slowly advancing the reamer 20-30mm and retracting 50-80mm. This allows the irrigation fluid to flow in front of the reamer for cooling. It is important to visualize the reamer under fluoroscopy to ensure reaming remains within the IM canal, as the reamer’s sharp edges can penetrate the cortex without attention to detail during this step. It is also important to periodically check that the reaming aspirate is flowing through the tube into the suction canister. Reaming up to the proximal tibial metaphysis is recommended, as there is greater concentration of osteoinductive and osteoconductive cells in metaphyseal bone 6 . After it reaches its desired depth, the reamer is removed. The irrigation and suction are turned off and the suction canister containing the bone graft is removed. The bone graft is compressed using the plunger in the canister. After it is compressed, it is removed and placed on the back table for later use. The RIA guidewire is removed and the previous guidewire for the IM nail is again placed. The rod is inserted and the bone graft is packed into the arthrodesis sites. The specific nail utilized will dictate the order of locking screw insertion and the specific compression that can be attained. Finally, the previously harvested bone graft is additionally placed at the sites of intended arthrodesis. The wounds are closed in a routine manner. The patient is placed in a bulky Jones compression dressing with a posterior splint. Sutures are removed at approximately 10-14 days. Patients are maintained in a nonweightbearing cast for 8 weeks and the gradually progressed to weightbearing depending on healing. REFERENCES: 6. Finkemeier CG. Bone-grafting and Bone-graft Substitutes . J Bone Joint Surg Am 2002; 84:454-464. 7. Nichols TA, Sagi HC, et al. An Aalternative Source of Autograft Bone for Spinal Fusion: Technical Case Report. Neurosurgery 2008;62:E179. 8. Kobbe P, Tarkin IS, et al. Voluminous Bone Graft Harvesting of the Femoral Marrow Cavity for Autologous Transplantation. An Indication for the “Reamer-Irrigator-Aspirator” Technique. Unfallchirurg 2008;111:469-72. 9. Stafford PR, Norris B. Reamer-Irrigator-Aspirator as a Bone Graft Harvester. Tech Foot Ankle Surg 2007;6:100-107. Figure 1: A) Assembled RIA. There is 1 tube with irrigation fluid fed into the drive shaft and a 2nd tube for aspiration of contents into the cannister. B) Reamer head-note the sharp edges and deep flutes of the reamer. C) Bone graft harvested via RIA technique. D) Immediate post-operative image with RIA bone graft placed at arthrodesis site. A B B C D