Cartiva synthetic cartilage implant hemiarthroplasty for treatment of hallux rigidus

B. Brandao, A. Aljawadi, A. Fox, A. Pillai

Objectives: Cartiva synthetic cartilage implant (SCI) is licenced for use in management of symptomatic hallux rigidus in several countries including the UK. As for now, there are no independent comparative series for treatment of hallux rigidus utilising polyvinyl alcohol implants.

Study design and methods: Patients at a single centre with symptomatic hallux rigidus who underwent Cartiva SCI implant procedure were identified. First metatarsophalangeal joint arthritis was radiographically graded according to the Hattrup and Johnson (HJ) classification. Pre-operative and post-operative patient-reported outcomes were evaluated using the Foot and Ankle Ability Measure (FAAM) activities of daily living subscale and the Manchester-Oxford Foot Questionnaire (MOXFQ).

Results: 66 patients (19M, 47F) (43R and 23L) were followed up for an average of 14 months (min=2, max=36). 17 patients suffered from HJ2/moderate arthritis and 49 patients with grade HJ3/severe arthritis. Post-operative mean FAAM scores showed statistically significant improvement (p< 0.0001). Patients reported a 40% increase in functionality during activities of daily living. All 3 MOXFQ Domain scores improved significantly (p< 0.02). The Index score improved by 28 points (p< 0.0001). There was no correlation between length of follow up or age and PROMs (r=0.129). No statistical difference was demonstrated between sexes. However clinically, males and older patients exhibit better outcomes. There was a 89.4% patient satisfaction with the use of Cartiva.

Conclusions: Our study shows excellent results with statistically significant improvements in functional outcomes, and promising short-term follow-up with low early revision rates. Pain in particular was significantly reduced. One third of patients developed post-operative stiffness requiring a manipulation under anaesthesia. Patient selection is key. Additional imaging may be required to assess sesamoid osteoarthritis. At 3 years the implant has demonstrated to be safe and efficacious in the management of hallux rigidus. Durability and survivability of the implant will continue to be studied in this cohort.