Abstract
Category:
Midfoot/Forefoot; Other
Introduction/Purpose:
Arthritis of the 1st metatarsophalangeal (MTP) joint is a common condition. Traditionally, advanced disease has been treated with arthrodesis. In 2016, Cartiva, a cylindrical polyvinyl 1st MTP implant, was approved for use in this condition by the FDA upon the basis of a company-sponsored, nonblinded, randomized controlled trial (MOTION) that reported noninferiority to arthrodesis at a -15% difference of proportions margin using a multipart ad hoc definition of surgical success. A subsequent independent level IV case series reported poor PROMIS score outcomes for the procedure but lacked any preoperative data. We report the short-term reoperation rate and pre- and postoperative VAS pain score outcomes for Cartiva in an independent multicenter series.
Methods:
A retrospective, multicenter review was performed of patients who had a Cartiva hemiarthroplasty placed from 2016- 18 and who had at least 6 months of follow-up. Demographic information, surgical data, and prospectively collected VAS pain scores on a 0-100 point scale on were reviewed. The primary endpoint was reoperation of the implant, defined as removal or revision during the follow-up period. Implant subsidence was measured by comparing early postoperative radiographs with final radiographs. Subgroup analysis was performed comparing Cartiva failures to the remainder of the group.
Results:
Fifty-three patients with 56 operated toes were included. Forty-seven (88.7%) females and 6 (11.3%) males had a mean age of 57.7 +- 7.14 years (range 43-73). At an average follow-up of 11.1 +- 4.24 months, there were 6 (10.7%) reoperations. Younger age was the only factor found to be associated with failure of the implant (p=.043). Radiographic subsidence >1 mm was identified in 26.6% of patients but did not correlate with failure. VAS pain scores improved from a preoperative average of 49.7 +/- 24.8 to a postoperative average of 33.1 +- 23.3 at final follow-up. Despite this improvement, 40.4% of patients failed to show a 30% improvement, the MCID, in their VAS pain score, and 42.6% of patients had residual pain scores above 30.
Conclusion:
Our cohort had a 10.7% reoperation rate for the Cartiva implant which is comparable to the results of the MOTION trial. Although aggregate results demonstrated a statistically significant improvement in VAS pain scores, many patients failed to have a satisfactory outcome as demonstrated by the large standard deviation and low achievement of the MCID. Compared to the 1-year results of the MOTION study, our final VAS pain scores were slightly worse, but the very high variance mirrored that reported in the company-sponsored trail (17.8 +- 23.0). This suggests that use of Cartiva does not reliably produce satisfactory pain outcomes.