After the evaluation of 200 conventional inserted ankle prosthesis and an additional 100 endoprosthesis with minimized approach. This resulted in the development of the new surgical technique.
In 2007 and 2008, approximately 200 ankle prostheses were inserted. 18% of these operations were selected for the keyhole technique and they were all successfully implemented.
With the Minimal-Invasive Surgery (MIS-TAA) the incision is approximately 5-6cm. This is a 2/3 reduction of the conventional incision. During the soft-tissue preparation, the following criteria are taking into consideration:
The extensor tendon was left in their tendon sheaths. Exploration of the ankle situs was performed in “moving windows technique“, which means without continuous soft tissue distraction or use of a spreader. With the assistance of special adapted tools and adequate skill, no additional incisions were needed to be made.
The TAA could be inserted through that small incision in press-fit technique. Once the implantation has been inserted, a four-layer wound closure and appropriate post-operative treatment was implemented.
All MIS-TAR-Implantation were performed successfully. A change to conventional surgical technique was not necessary. The number of additional procedures remained the same as in the conventional open technique and total operation time was not extended.
No patient experienced wound complications or infections (Purulent Inflammation) and there were significantly fewer problems than with the conventional technique. Therefore patients could start with mobilization and physical therapy much earlier. Patients were discharged from the 5th day in hospital.
The MIS-TAA in follow-up examination showed a correct prosthetic position of the Ankle mortise. Patients were extremely satisfied with the cosmetic result and achieved a good ankle movement of an average of 47°.