HYALEX MTP hemiarthroplasty for great-toe arthritis

The Hyalex First-in-Human Study - A Prospective, Single-Arm, Feasibility Study of the HYALEX SLALOM MTP Hemiarthroplasty Implant

This will try a synthetic HYALEX implant to replace the end of the big toe bone to reduce pain and improve motion in adults with first metatarsophalangeal (MTP) joint arthritis.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 20 (estimated)
• Ages: 21 Years to 75 Years
• Sex: All
• Sponsor: Hyalex Orthopaedics, Inc. (Industry-sponsored)
• Locations: 1 site (Lodz)
• Trial ID: NCT07538141 on ClinicalTrials.gov

What this trial studies

The HYALEX SLALOM MTP Hemiarthroplasty System is a synthetic implant made of HYALEX cartilage material bonded to a titanium backing that replaces the distal metatarsal surface of the great toe. Eligible adults (21–75 years) with degenerative or post‑traumatic first MTP arthritis (ICRS grade 2–4), BMI ≤ 38, and preoperative VAS pain >40 may undergo the surgical implant procedure. The protocol requires adequate bone stock and excludes patients with certain allergies, opposing high‑grade phalangeal cartilage damage, bilateral disease requiring simultaneous treatment, or other ipsilateral lower‑limb pathology that needs active treatment. Outcomes focus on postoperative pain and joint function compared with baseline.

Who should consider this trial

Good fit: Adults aged 21–75 with symptomatic first MTP degenerative or post‑traumatic arthritis (ICRS 2–4), preoperative VAS pain >40, BMI ≤38, and sufficient bone stock without contraindicated allergies are ideal candidates.

Not a fit: Patients with known allergies to polyurethane, acrylic, bone cement, or titanium; inadequate bone (less than 2 mm of vital bone around the implant site); opposing phalangeal cartilage lesions of ICRS grade 3–4; bilateral MTP disease needing simultaneous treatment; active ipsilateral lower‑limb pathology requiring treatment; or prior cheilectomy complications are unlikely to benefit.

Why it matters

Potential benefit: If successful, the implant could reduce pain and preserve motion in the big toe, offering an alternative to fusion or more invasive joint replacements.

How similar studies have performed: Similar synthetic cartilage hemiarthroplasty approaches (for example, polyvinyl alcohol hydrogel implants) have shown positive results in some published studies, but long‑term, device‑specific evidence for the HYALEX system is limited.

Eligibility criteria

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

Where this trial is running

Lodz

• Sporto — Lodz, Poland (Recruiting)

Study contacts

• Principal investigator: Marcin Domzalski, MD — SPORTO, Łódź, Poland
• Study coordinator: Chris Cain

Conditions Hallux Valgus; Hallux Limitus; Hallux Rigidus; Arthritis