A Closer Look At Total Ankle Replacement Revision
Given the challenges of total ankle replacement, these authors provide a historical overview of one of the early implants, review common complications and offer salient insights on revisional treatment.
It is generally accepted that the early history of total ankle replacement arthroplasty consisted of uninterrupted failure and accordingly was rendered nearly extinct.1-7 Dissatisfaction with ankle joint arthrodesis, the success of total hip and knee implant arthroplasties, and the efforts of surgeons and industry to address the problems associated with prior implant designs have resulted in renewed interest in total ankle replacement.8-12
One total ankle replacement available for use in the U.S. is the Agility® Total Ankle Replacement System (DePuy Orthopaedics). Frank G. Alvine, MD, who invented the device, states that the prosthesis was designed around three specific areas of study: (1) CAD-CAM computer analysis of 100 normal ankle radiographs; (2) modes of failure (specifically subsidence, impingement and malalignment) of previous generations of total ankle replacements; and (3) surgical approach including accuracy of insertion and instrumentation including an external fixation device to tension the ligaments.13,14
The design process started in 1978 and the first patient received the implant in 1985. It was subsequently marketed in 1992 as the “DePuy Alvine Total Ankle Prosthesis.”15 Between 1985 and 2007, the implant went through a total of four generations and seven phases of implant improvement.13,14,16 Of note, the ankle implant is FDA approved only for use with polymethylmethacrylate (PMMA) cement fixation as demonstrated in the technique guides.17,18
Between 1985 and 1998, there were several early phases of improvement with the implant. These improvements included thickening of the tibial titanium component; augmenting the posterior dimensions of the tibial component; changing the metallurgy of the talus from titanium to cobalt-chrome; increasing the sizes from three to six; developing a rectangular “revision” talar component; and adding revision ultra-high molecular weight polyethylene (UHMWPE) with an additional 2 mm thickness as well as a half-column design for the 0-mm UHMWPE insert to make revision insertion of the bottom-loaded insert easier.14 These changes were based on the continued effort of the inventor to refine the implant and improve his patient’s outcomes as well as the release of the implant to a select group of orthopaedic surgeons across the U.S. in 1993 and their ongoing feedback.