The HYALEX SLALOM MTP Hemiarthroplasty System consists of a synthetic implant designed to replace the distal metatarsal surface of the great toe for treatment of arthritis . The system is composed of the HYALEX MTP Implant and instrumentation. The implant consists of the HYALEX Cartilage material bonded to a titanium backing.

Inclusion Criteria:

1. 21-75 years;
2. Body Mass Index (BMI) ≤ 38;
3. Degenerative or post-traumatic arthritis of the first metatarsal joint with ICRS grade 2, 3, or 4;
4. Pre-operative VAS pain score of >40;
5. Presence of good bone stock, without need for bone graft

Exclusion Criteria:

1. Known allergy to polyurethanes, bone cement, acrylic, or titanium;
2. Due to anatomy and/or lesion location, inability to position the implant flush or slightly proud relative to the articular surface precluding proper device placement;
3. Lack of 2mm of vital bone on all sides of implant site;
4. Cartilage lesions on the phalanx of ICRS Grade 3 - 4 opposite the lesion intended for treatment;
5. Additional ipsilateral lower limb (hip, knee, ankle, or foot) pathology that requires active treatment (e.g., surgery, brace);
6. Bilateral degenerative or post-traumatic arthritis of the MTP joints that would require simultaneous treatment of both MTP joints;
7. Previous cheilectomy resulting in inadequate bone stock;
8. Diagnosis of gout;
9. Hallux varus to any degree or hallux valgus >20;
10. Hyper mobility at proximal metatarsal joint;
11. Interphalangeal angle >15