Surgical method and instrumentation assembly for positioning an ankle prosthesis

A surgical ankle repair method comprising the steps of:

• a) providing an instrumentation assembly for positioning an ankle prosthesis, the instrumentation assembly including a talar alignment instrument and a cutting block, the talar alignment instrument comprising a front portion and two fins extending from the ends of the front portion, said fins being adapted to be positioned in gutters extending below a tibia of a patient and around a trochlea of a talus of the patient, each fin including a reference marker, the cutting block comprising a tibial alignment structure and a recess which engages a protrusion provided on the talar alignment instrument,
• b) positioning the talar alignment instrument such that the fins are disposed in the gutters extending below the tibia and around the trochlea of the talus;
• c) aligning the talar alignment instrument so that the fins are parallel to the rotational plane of the talus, perpendicular to the rotational axis of the talus, and so that the reference markers are aligned with a longitudinal axis of the tibia;
• d) confirming alignment of the reference markers via imaging technology;
• e) mechanically attaching the talar alignment instrument to the talus;
• f) fastening the cutting block to the talar alignment instrument such that the recess engages the protrusion locked in a parallel orientation to the rotational plane of the talus;
• g) rotating the talus such that the tibial alignment structure is in a parallel alignment to the longitudinal axis of the tibia, thereby correcting any varus or valgus deformity of the talus;
• h) attaching the tibial alignment structure to the tibia;
• and
• i) performing a first resection of the talus and at least one resection of the tibia using the cutting block.