Surgical Instrumentation Assembly for Positioning an Ankle Prosthesis

#The present invention relates to a surgical instrumentation assembly for positioning an ankle prosthesis.

#Placement of an articular prosthesis at the ankle of a patient during a surgical operation, typically from an anterior approach path, requires preparation notably by resections, of the lower end of the tibia, as well as often the upper end of the talus of the patient, in order to permanently fix thereon the tibia and talus implants belonging to the ankle prosthesis. In practice, once the bone preparations are carried out, the surgeon frequently resorts to phantoms of prosthetic implants, allowing the surgeon to make sure that these preparations are suitable and that additional bone cutting or additional resurfacings are not necessary. These phantoms are not necessarily of the same shape as the corresponding implant.

#Sometimes, a patient may be fitted with an initial fitted ankle prosthesis, and the initial implantation may be revised subsequently; in the case of a revision, the talar implant is often provided with a talo-calcaneal anchoring keel, which may be sufficiently long for stabilizing the talus implant facing both the talus and the calcaneus of the patient. This being said, this type of ankle prosthesis with a long keel may of course be positioned as a first intention prosthesis, notably if the bones of the foot are highly damaged. It is understood that the positioning instrumentation for an ankle prosthesis with a long keel should allow the surgeon to prepare the talus and the calcaneus accordingly, so that these bones are ready to receive the aforementioned long keel in an ad hoc housing. Further, in spite of all the care which the surgeon may provide in handling such instrumentation, notably with a significant intervention time, the risks are not negligible that the preparation of the aforementioned housing might be not satisfactory, in the sense that the implantation of the talus component resulting from this does not allow good subsequent articular cooperation with the tibial component attached to the tibia.

#FIGS. 1 to 3 illustrate an ankle prosthesis, FIG. 1 being an exploded perspective view and FIGS. 2 and 3 corresponding to elevational views along the arrows II and III of FIG. 1 respectively.

#FIG. 4 is a perspective view of the ankle of a patient illustrating a first step for preparing this ankle with view to positioning of the prosthesis of FIGS. 1 to 3, this first preparation step being carried out by a corresponding portion of an exemplary embodiment of an instrumentation assembly according to embodiments of the present invention.

#FIG. 5 is a view similar to FIG. 4, illustrating a second step for preparing the ankle with a corresponding portion of the instrumentation, according to embodiments of the present invention.

#While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

#In FIGS. 1 to 3, an example of an ankle prosthesis 1 is illustrated. This prosthesis includes three distinct components to be implanted at the joint of an ankle of a human being, in this case, for the example considered in the figures, a right ankle of such a human being. These components are a tibia implant 10, a talus implant 20 and a prosthetic shoe 30.

#For convenience, the following of the description is oriented relatively to the bones of an ankle in their anatomic position, i.e. the term of “posterior” or “rear”, “anterior” or “front”, “right”, “left”, “upper”, “lower”, and the like, are understood with respect to the ankle of a patient standing on his/her feet on a substantially horizontal surface. Also the term of “sagittal” corresponds to a direction in the antero-posterior direction, vertically on the middle line of the ankle, while the “front plane” corresponds to a vertical plane perpendicular to the sagittal plane of the ankle.