Ankle Arthrodesis Using Ring External Fixation - Orthofix.com

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Special Focus: Ankle Arthrodesis Using Ring External Fixation FIGURE 17. Compression is applied through the tibiotalar joint. between the calcaneus and distal tibia is sufficient. However, in patients with intact subtalar joints, compression should only be applied across the tibiotalar arthrodesis site. To accomplish this, a fixed Bdistal ring block^ is applied to isolate the talus from the calcaneus and protect the subtalar joint. Through either extended connectors from the foot frame or an additional intermediate ring, 1 or preferably 2 thin wires are placed in the talus and appropriately tensioned. Care must be taken to ensure that the pins are indeed in the talus and do not engage the malleoli (Figs. 16A, B). 14. Compression may be applied after all components of the external fixator have been tightened, and all thin wires have been tensioned. If the Steinmann pin placed longitudinally for provisional fixation is directly perpendicular to the arthrodesis site, then it can be used as a Brail^ during compression. The provisional fixation is typically removed at the end of the case (Fig. 17). FIGURE 18. Intraoperative fluoroscopy after compression. Note the bending of the tensioned thin wires in the talus. 15. Intraoperative fluoroscopy is used to confirm adequate bony apposition at the arthrodesis site and proper pin position (Fig. 18). 16. If there is concern for inadequate compression or a tendency toward varus malalignment at the tibiotalar joint, consideration should be given to a fibular osteotomy, if it was not already cut or resected during the approach. We favor an oblique osteotomy, proximal lateral to distal medial through a 2- to 3-cm incision. 17. The wires are appropriately cut and bent. Alternatively, the pins can be cut flush with the external fixator. However, if a wire needs to be tensioned later, leaving a carefully bent residual wire allows for this. 18. Sutures are used to close any extension of the stab incisions created for pin placement. FIGURE 19. A and B, Example of Taylor Spatial Frame being used for revision ankle arthrodesis that required posterior translation of the talus in addition to tibiotalar compression. Volume 5, Issue 3 157 Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
FIGURE 20. Patient weight-bearing with external fixator. A foot plate with tread has been applied to the foot frame. 19. Sterile dressings are applied and wrapped relatively tightly over the pins to provide stability at the skin/wire interface to decrease the likelihood of pin tract infections. Traditional Step-by-Step External Fixation Method 1. The proximal ring/ring block is usually attached first (Fig. 6). A reference (thin) wire can be placed perpendicular to the anatomical axis of the tibia. The proximal ring is attached to this reference wire. A second thin wire is placed at a different angle and attached to the proximal ring that is being held in an orthogonal position. Ideally, this second wire should be placed as close to 90 degrees from the first to create FIGURE 22. Radiograph demonstrating loose proximal pins suspicious for pin tract infection/osteomyelitis. the greatest stability. In placing 2 thin wires on the same ring, one should be above and the other below the ring. If the pins are placed on the same side of the ring, they will collide and displace. These thin wires are tensioned. A second ring can be placed and secured in a similar manner. The 2 rings are connected by sockets or short threaded rods. The spacing between these 2 rings is variable and should allow for adequate stability (ie, adequate space should be left to permit half pin placement between the rings. To ensure that the 2 rings are symmetrically oriented, it may be easier to first connect the 2 rings, slide them onto the lower leg, have FIGURE 21. A, Ankle arthrodesis site obscured by external fixator, making assessment of fusion difficult. B, CT scan to facilitate assessment of fusion site. 158 Special Focus: Easley et al Techniques in Foot and Ankle Surgery Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Page 1 and 2: Techniques in Foot and Ankle Surger
Page 3 and 4: FIGURE 3. External fixation alone d
Page 5 and 6: FIGURE 8. One to 2 cm must be maint
Page 7: FIGURE 15. A and B, A supplemental
Page 11 and 12: contaminating the surgical wound. M
Page 13 and 14: performed with Ilizarov external fi

Ankle Arthrodesis Using Ring External Fixation - Orthofix.com

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