Infinity ankle arthroplasty with traditional instrumentation and PSI prophecy system: preliminary results
Piero Giardini,corresponding author1 Paolo Di Benedetto,2 Domenico Mercurio,3 Renato Gisonni,2 Marco Molinari,1 Araldo Causero,2 and Fabrizio Cortese3Ankle
Background and aim:
Ankle arthrodesis has been considered for many years the surgical Gold Standard for the treatment of advanced ankle arthritis; prosthetic replacement of the tibio-talar joint played a secondary role in the treatment of the degenerative pathology of the ankle in relation to the higher rate of failures and complications compared to ankle fusion. The introduction of last generation ankle prostheses lead to better outcome, a lower rate of complication and a longer survival of the implants. Patient Specific Instrumentation (PSI) represents one of the most recent innovations introduced on the market of ankle arthroplasty: PSI is proposed as a surgical technique capable of making ankle arthroplasty more accurate and more reproducible compared to ankle replacements performed with standard referencing guides.
Methods:
Aim of the study is to report early clinical (AOFAS score) and radiographic outcomes (alignement of tibial component) obtained from a single surgeon experience (FC) by implanting the same ankle prosthesis (Infinity, Wright Medical Technologies) using a standard (STD) or a PSI instrumentation.
Results:
Unlike no difference in the average increment of normalized sub score related to function in each group (PSI vs STD), the analysis of normalized pain sub score pointed out a greater average improvement in the PSI group (+75%) compared to the STD group (+62%); this result has been adovacated to the absence of post operative gutter impingement syndrome in the PSI group compared to the STD referencing group. The analysis of post operative radiographic angles revealed a more accurate and reproducible positioning of the components in the PSI group compared to the STD group. Furthermore, ankle arthroplasty performed with PSI instrumentation reported a reduction of both surgical times and the need of intraoperative fluoroscopy compared with a standard instrumentation.
Conclusions:
With limitations related to the short follow up and the low number of patients, PSI ankle arthroplasty achived more accurate and reproducible clinical and radiographic results compared to standard referencing instrumentation; long-term follow-up are needed to demonstrate whether a better positioning of the implant is associated with an increased survival of the prosthesis and therefore justifies the additional costs associated with this technology. (www.actabiomedica.it)
Link to article