JOINT COMPRESSION AND FINAL FRAME ADJUSTMENTS
Once all rings are secured to the bone with half-pins and wires, the previously placed Steinman pins, and K-wires through the heel are removed. Both ankle and subtalar joint alignments are rechecked, and then axial compression is placed through the foot ring with the knee extended and the struts unlocked. Static or telescopic struts are used to achieve 8 to 10 mm of bony compression. X-rays are taken before and after to analyze final joint compression and alignment. Struts should be sequentially tightened (1/2 turn of a static strut) 1 at a time as final tightening of 1 strut alone can bind and interfere with both the compression and tightening of the remaining struts.
Once final compression is achieved, the struts are locked, and the front foot arch is closed anteriorly and connected to the distal tibia ring for increased stability (Figures 6A-6D). Each pin and wire is covered in a sterile dressing followed by gauze to allow for soft tissue padding. The entire frame is then overwrapped in bias stockinette rolls or ace wraps.
Walking attachments can be added immediately to the frame that allows for early weight-bearing. Rocker shoe attachments with a 15° anterior and posterior slope and rubber soles can help offload the ankle and subtalar joints, decrease pressure on heel strike, and reduce ankle motion during ambulation (Hoffmann LRF, Stryker).
POSTOPERATIVE PROTOCOL
Depending on individual characteristics, patients can be immediately weight-bearing in the circular frame. Patients with Charcot neuroarthropathy are recommended to remain non-weight-bearing for the first 2 months to reduce the likelihood of pin, wire, and frame breakage along with nonunion. Pin and wire site care and maintenance are initiated the day after surgery and continue on a daily basis for the duration of frame placement. Sutures are removed 4 to 5 weeks after surgery to ensure adequate wound healing. Serial X-rays are taken monthly to analyze fusion sites.
If pins or wires become infected, patients are placed on oral antibiotics, and both pins and wires can be removed or exchanged in the operating room. Once fusion is achieved in 3 to 8 months (Figures 7A-7C), the frame is removed in the operating room, and fusion sites are examined under dynamic fluoroscopy. If fusion is confirmed, patients are made weight-bearing as tolerated in a short-leg cast or tall CAM boot for 6 to 8 weeks, and then transitioned to an ankle brace in an accommodative shoe.
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