Interpositioned metallic prosthesis for hallux rigidus: review of 42 caseswith a metatarsophalangeal prosthesis

Purpose of the study We report outcome at a mean 4.8 years follow-up in 42 patients with hallux rigidus treated by metatarsophalangeal interposition t hin prosthesis flat concave with a lateral capsular fixation. Materials and methods The 42 patients were treated from 1987 to 1997. Sixti ne prostheses were implanted for osteoarthritis was grade (n = 2), grade II (n = 28), and grade III (n 12). Groulier's clinical criteria and Regnauld' s radiologic criteria were used to assess outcome, Results We observed 22 very good, 12 good, 4 fair, and 4 poor results. Ther e was no significant modification in the forefoot morphology. Discussion The Sixtine prosthesis provided a global improvement in pain and motion though there was an important difference between patients with grad e I and grade Il osteoarthritis, who experienced major improvement, and tho se with grade III disease. A good overall result requires proper prosthetic centering. Subluxation or translation does not appear to be compatible wit h good results. Among 3 cases with overt dislocation, 1 recovered an accept able articular space with a good overall result. Two poor results and 3 fai r results were observed in patients with condensation of the phalangeal bas e. These bone condensations appeared in postoperative Egyptian feet. The Si xtine prosthesis may protect the interphalangeal articular space of the gre at toe, avoiding damage and rearward displacement of sesamoid bones. It ens ures primary stability and may be left in place. Conclusion We found that the Sixtine prosthesis is best indicated in hallux rigidus patients with grade II osteoarthritis.