How does Cartiva interpositional arthroplasty compare to arthrodesis in the treatment of hallux rigidus? A retrospective comparative study with 12 month follow up

S. Trowbridge, T. Lewis, R. Shehata, B. Lau, S. Lyle, R. Ray

Background: Hallux rigidus is a common condition characterised by first metatarsophalangeal joint (MTPJ) degeneration, pain and limited range of motion (ROM). The gold standard surgical treatment is arthrodesis, providing good pain relief but sacrifices ROM. Recently the Cartiva synthetic cartilage implant (SCI) has been utilised as an interpositional arthroplasty, aiming to reduce pain whilst preserving range of motion. Current evidence for Cartiva SCI is largely based on a single cohort with mixed outcomes. We sought to evaluate the clinical outcomes of Cartiva SCI compared to arthrodesis undertaken in our centre.

Methods: Retrospective review of patients undergoing Cartiva SCI or arthrodesis for treating hallux rigidus was conducted. Preoperative arthritis was radiographically graded using the Vanore classification. Patient reported outcomes (PROMs) were assessed using EuroQol 5-dimension score (EQ-5D-5L) and Manchester-Oxford Foot Questionnaire (MOXFQ).

Results: Between 2017 and 2020 there were 33 cases (17 Cartiva, 16 arthrodesis, mean age 59.0±9.9 years) with a mean follow up of 2.3 years. For the first MTPJ arthrodesis cohort, the MOXFQ domain scores were: Index 3.9±5.8, Walking/Standing 5.1±7.6, Pain 3.2±5.0, and Social Interaction 2.6±4.0. EQ-5D-5L Index score was 0.828±0.270 and the EQ-VAS was 72.5±23.3. For the Cartiva cohort, the MOXFQ domain scores were: Index 7.7±6.0, Walking/Standing 8.9±7.9, Pain 7.1±5.0, and Social Interaction 6.4±5.4. EQ-5D-5L Index score was 0.631±0.234 and the EQ-VAS was 74.8±20.8. There was no statistically significant difference between any MOXFQ domain or EQ-5D-5L scores. However, a negative trend in MOXFQ domains was identified for the Cartiva group, as well as a reoperation rate of 23.5%.

Conclusions: The Cartiva SCI demonstrated no advantage over arthrodesis in PROMs, despite the presumed benefit of preserved ROM. A significant reoperation rate was also observed. Surgeons should be cautious in the use of this novel implant.