Since its launch in 2014, a low-profile fixed-bearing prosthesis that is implanted under fluoroscopic guidance has produced positive outcome data. According to results of a recent clinical study of the implant led by Ian Sharpe, FRCS (Tr&Orth), in Exeter, United Kingdom, patients who underwent the procedure have required no revision procedures to date.
Furthermore, none of the 25 patients who underwent total ankle replacement with the Infinity Total Ankle Replacement System (Wright Medical Technology Inc.) prosthesis experienced radiographic loosening during a mean follow-up of 12 months postoperatively, according to Andrew King, MBChB, MRCS.
“The guide that the prosthesis uses allows you to make your bone cuts accurately with a minimally invasive dissection. The wounds seem to heal fast, and we have not had any wound breakdowns. That allows us to get the ankle moving quickly, allows weight-bearing faster and the alignment is so good that the anatomical axis helps patients get back to decent levels of activity quickly,” King, an orthopaedic trainee at the Royal Devon and Exeter Hospital, in Exeter, told Orthopaedics Today Europe.
Positive patient reported outcomes
The results of this study are scheduled to be presented in an ankle joint/osteoarthritis session at the 17th EFORT Annual Congress in Geneva.
According to King and colleagues, the indication for total ankle replacement in these patients was either osteoarthritis or inflammatory arthritis. The patients were prospectively followed for a mean of 12 months postoperatively.
Based on direct patient questioning and patient assessments done using the Manchester-Oxford Foot Questionnaire, the investigators reported all the patients had excellent outcomes.
According to King, the Infinity prosthesis allowed patients to regain mobility more rapidly than what has been reported with earlier designs of total ankle prostheses.
“The radiological guide for the Infinity leads to accurate clinical alignment and patients can get moving faster,” he said.
Low learning curve
King noted the fluoroscopic navigation used to implant the prosthesis allowed for excellent alignment of all prostheses during implantation. It also helped surgeons restore anatomical alignment by using a reproducible and quickly assimilated technique.
He said the radiation exposure is minimal during the procedure, despite it being fluoroscopically-guided. In addition, the learning curve for prosthesis implantation is fairly short, King said.
“The time required to perform the operation accurately falls quickly, and the fluoroscopic guidance use reduces resulting in low levels of radiation exposure required for the procedure,” he said.
The results of the study are early, but highly encouraging, according to King and colleagues. They noted the long-term results will be followed up easily because patients in this study are being monitored via the United Kingdom National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. – by Robert Linnehan
- King A, et al. Paper #1862. Scheduled to be presented 1 June 2016 at 15:30 to 16:30 in the Geneva Room at: 17th EFORT Annual Congress – A combined programme in partnership with swiss orthopaedics; 1-3 June 2016; Geneva.
- For more information:
- Andrew King, MBChB, MRCS, can be reached at Royal Devon and Exeter Hospital, Barrack Rd., Exeter, Devon EX2 5DW, United Kingdom; email: firstname.lastname@example.org.
Disclosure: King reports no relevant financial disclosures.