EARLY OUTCOMES AND SURGICAL LEARNING CURVE OF THE MOBILITY TOTAL ANKLE REPLACEMENT COMPARED TO THE STAR ANKLE REPLACEMENT

Abstract

In 2004, our centre has changed from the “STAR” to the “Mobility” Total Ankle Replacement device and a study was undertaken in order to ascertain if there was a learning curve to useage of this new device and perform a comparison in terms of survival, function, additional procedures and complications.

The indications were 55% osteoarthritis, 30% Rheumatoid and 8% JIA with the remainder being haemophiliac, haemochromatosis and ankylosing spondylitis.

One third of TARs in this unit are combined with additional procedures such as subtalar fusion. Only isolated TARs were considered in this study and the tourniquet time, wound problems, length of stay and known complications for the last 20 STAR TARs was compared to the first 20 Mobility TARs.

68 Mobility TARs have been implanted since Oct 2004 and survival data was collected for this entire cohort and compared to a similar number of STARs.

Results: There was no significant difference in operative time (63 vs 65 mins) between the prostheses, no difference in intra-operative complications (0), no difference in deep infections (0% ) and a minimal difference in hospital stay (4.3 vs 5.1 days) due to non-surgeon factors.

The survival curve of the mobility and STAR shows no loss of the Mobility due to revision at up to 3 years.

Clinical outcome scores will be presented.

Summary: There is no learning curve for an experienced Foot and Ankle Surgeon in changing prosthesis and no apparent effect on morbidity for the patient. All 40 TARs are in situ and functioning acceptably at up to 3 years.

The early results for this new prosthesis show no cause for concern and surveillance is ongoing.