Revision rates after total ankle arthroplasty in sample-based clinical studies and national registries

Techniques and pitfalls with the Salto prosthesis: our experience of the first 15 years

The Salto total ankle replacement system has shown to be a viable alternative in the treatment of symptomatic arthritis. However, although outcomes after total ankle replacement are promising, an exact analysis of surgical technique could help to improve them. Based on a 15 years experience with the Salto Total Ankle replacement system, the uthors discuss the surgical technique and its pitfalls, its inications and limitations in current practice.

Management of specific complications related to total ankle arthroplasty

Total ankle arthroplasty (TAA) has evolved over time and modern 3-component implants offer good and reliable clinical results. Despite recent improvements, TAA is still associated with a relatively high incidence of complications. Surgeon experience seems to play the most important role. This review highlights the most common intraoperative and postoperative complications, such as malleolar fracture, impingement, cyst formation, malalignment, and loosening, and offers a differentiated concept for their management.

RANKL in the osteolysis of AES total ankle replacement implants

Peri-implant tissue reactions in failed total ankle replacement (TAR) are characterized by early developing peri-implant osteolysis. The hypothesis of the study was that this reaction is mediated by receptor activator of nuclear factor kappa B ligand (RANKL). Samples of peri-prosthetic tissues from failed TAR implants were stained for macrophages, RANKL, its receptor RANK and osteoprotegerin (OPG), and compared to control samples. The failed TAR implants were surrounded by implant capsule, synovial lining-like interface membrane or necrotic tissues. Infiltrating scavenger receptor I positive CD163(+) macrophages were frequent, in particular around necrotic soft tissues or bone sequestrate, and possibly in part formed due to ischemia and mechanical factors. In contrast, implant-derived wear debris was scanty. Still many RANK(+) macrophages were often seen in close contact with RANKL(+) mesenchymal cells, whereas OPG was mostly located at a distance in vascular endothelial cells. Foreign body giant cells were frequent. RANKL seems to stimulate locally accumulated CD163(+) RANK-expressing cells to fusion, which leads to the local formation of multinuclear foreign body giant cells (and probably of osteoclasts). Therefore, peri-implant osteolysis in early TAR implant failure seems to be caused by the RANKL-driven chronic foreign body inflammation directed against, not implant-derived particles, but against necrotic autologous tissues.

Application and survival curve of total hip arthroplasties: a systematic comparative analysis using worldwide hip arthroplasty registers

PURPOSE

The aim of the study was to compare primary total hip arthroplasty (THA) implantations between different countries in terms of THA number per inhabitant, age, and procedure type and to compare the survival curve including all THAs using hip arthroplasty registers.

METHODS

THA registers were compared between different countries with respect to the number of primary implantations per inhabitant and age, procedure type and survival curve. We performed a literature search for all national hip arthroplasty registers providing annual reports for 2009 or, if not available, a more recent period. The data from these reports were analysed in terms of number, age distribution and procedure type of primary THAs and survival curves.

RESULTS

We identified nine hip arthroplasty registers, which comprised sufficient data to be included. A large variation was found in the annual number of primary THA implantations per inhabitant. The procedure type varied greatly as well, e.g. in Sweden 67 % are cemented THAs whereas in Emilia-Romagna (Italy) 89 % are cementless THAs.

CONCLUSIONS

This study revealed large differences in terms of the annual number of primary THAs per inhabitant and primary THA procedure type across countries. These data can be used to rank local primary THA implantations within an international context.

Revision rate of Birmingham Hip Resurfacing arthroplasty: comparison of published literature and arthroplasty register data

PURPOSE

Hip resurfacing arthroplasty has gained popularity for treating young and active patients who have arthritis. There are two major data sources for assessing outcome and revision rate after total joint arthroplasty: sample-based clinical trials and national arthroplasty registers. The purpose of this study was to evaluate the outcome of the Birmingham Hip Resurfacing (BHR) arthroplasty in terms of revision rate as reported in clinical studies and recorded by national arthroplasty registers.

METHODS

A comprehensive literature research was performed from English-language, peer-reviewed journals and annual reports from national joint arthroplasty registers worldwide. Only publications from MEDLINE-listed journals were included. The revision rate was used as the primary outcome parameter. In order to allow for direct comparison of different data sets, calculation was based on revisions per 100 observed component years. For statistical analysis, confidence intervals (CI) were calculated.

RESULTS

A total of 18,708 implants, equivalent to 106,565 observed component years, were analysed in the follow-up studies. The register reports contained 9,806 primary cases corresponding to 44,294 observed component years. Statistical analysis revealed a significant difference in revisions per 100 observed component years between the development team (0.27; CI: 0.14-0.40) and register data (0.74; CI: 0.72-0.76).

CONCLUSION

The BHR arthroplasty device shows good results in terms of revision rate in register data as well as in clinical studies. However, the excellent results reported by the development team are not reproducible by other surgeons. Based on the results of our study, we believe that comprehensive national arthroplasty registers are the most suitable tool for assessing hip arthroplasty revision rate.

Incidence of revision after primary implantation of the Agility™ total ankle replacement system: a systematic review

Revision of failed total ankle replacement remains a challenge with limited information available to guide treatment options. I undertook a systematic review of electronic databases and other relevant sources to identify material relating to the incidence of revision after primary implantation of the Agility™ Total Ankle Replacement System. In an effort to procure the highest quality studies available, studies were eligible for inclusion only if they involved patients undergoing primary Agility™ Total Ankle Replacement; had evaluated patients at a mean follow-up of 12 months or longer; included details of the revision performed; and included revision etiologies of aseptic loosening, ballooning osteolysis, cystic changes, malalignment, or instability. A total of 14 studies involving 2312 ankles, with a weighted mean follow-up of 22.8 months, were included. Of the 2312 ankles, 224 (9.7%) underwent revision, of which 182 (81.3%) underwent implant component replacement, 34 (15.2%) underwent arthrodesis, and 8 (3.6%) underwent below-knee amputation. No significant effect from the surgeon's learning curve on the incidence of revision or the type of revision surgery performed was identified. However, excluding the inventor increased the incidence of revision twofold, from 6.6% to 12.2%, and skewed the type of revision away from arthrodesis and toward implant component replacement or below-knee amputation. Regardless, the incidence of revision after primary implantation of the Agility™ Total Ankle Replacement System was less than historically reported and amenable to implant component revision more than 80% of the time. However, methodologically sound cohort studies are needed that include the outcomes after revision surgery, specifically focusing on what implant component replacement techniques are effective in enhancing survivorship of these revised implants and the role of custom-stemmed talar and tibial components have in revision of the Agility™ Total Ankle Replacement System. A direct comparison of the incidence of revision between the various contemporary total ankle replacement systems in common use is also warranted.