Silastic replacement of the first metatarsophalangeal joint: historical evolution, modern concepts and a systematic review of the literature

Silastic implants for the first metatarsophalangeal joint (MTPJ) have been in use for over 50 years. Initial reports were associated with high failure rates leading to development of new designs that are currently in use. The aim of this article is to review the historical evolution and the outcomes of silastic implants for the treatment of end-stage OA of the first MTPJ. Databases were searched for studies reporting the outcomes of silastic implants for the first MTPJ. Various relevant search terminologies were used. Studies reporting the outcomes of metallic implants or arthrodesis were excluded. The literature search revealed 522 studies, of which 28 were included. Eight studies used single-stemmed implants and 20 used double-stemmed implants for their patients. Twenty-eight studies had a total of 2354 feet with silastic replacements in 1884 patients (1968 to 2003) with an average age of 53 years and the average follow-up was 85.3 months. There were a total of 5.3% (124 feet) failed prostheses. Improvement in pain was reported in 76.6% (1804 feet) with an average patient satisfaction rate of 84%. Radiological changes around the implants were found to be significantly higher with single-stemmed implants (30.3%) compared to the double-stemmed implants (14.7%) (p < 0.05). Significantly more single-stemmed implants failed (11%) than the double-stemmed implants (3.6%) (p < 0.05). Despite the initial reports of failed implants and complications, first- and second-generation silastic implants were associated with high patient satisfaction and pain improvement. Current literature lacks long-term outcomes of implants currently in use. Cite this article: EFORT Open Rev 2019;4:77-84. DOI: 10.1302/2058-5241.4.180055