44: Complex Ankle Fusion and Tibial Lengthening Using the LATN Technique

Fig. 1

AP radiograph shows an attempted tibio-talo-calcaneal (TTC) fusion

Fig. 2

Lateral radiograph shows nonunion at the tibiotalar joint and loose hardware

3 Preoperative Problem List

Nonunion ankle fusion

Retained hardware

Leg length discrepancy

4 Treatment Strategy

Pre-operative labs: CBC, CRP, and ESR

Revision ankle fusion with removal of hardware

Application of Ilizarov-Taylor Spatial Frame for fixation

Intra-operative cultures

Staged lengthening after treatment of potential infection

5 Basic Principles

All nonunions should be assessed for possible infection, and fusion nonunions are no exception. Pre-operative antibiotics were held until after cultures were taken. Medial and lateral incisions were used to access the ankle and remove the medial and lateral malleoli. The tibial and talar surfaces were recut to the level of healthy bleeding bone. The cuts were apposed to maximize surface contact at the fusion site. BMP (Bone morphogenic protein ) was added to assist with fusion. The wounds were closed and the Ilizarov external fixator was applied using two rings. Strong compression was applied across the tibiotalar fusion site. The subtalar joint was previously fused and this was therefore compressed without concern. Weight bearing as tolerated ambulation was encouraged post-operatively. Post-operative leg lengths measured a 6 cm discrepancy, and the patient affirmed that she wanted to undergo distraction osteogenesis of the tibia. Cultures were negative. A staged lengthening was performed through a proximal tibial osteotomy site 4 weeks after the fusion surgery. The distraction proceeded at 1 mm per day for 60 days. To reduce the time in the frame and improve the healing of the new bone, a locked IM nail was inserted into the regenerate bone and the frame removed after only 3 months.