Mid-term Outcomes of First MTP Arthroplasty With Primus™ FGT Implant.

Study Overview
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Brief Summary
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Foot silicone implants suffer from bad reputation on the market, due to poor results obtained with the first generations of implants. Allergies to silicone, infections due to silicone and implants breakage used to be common with previous generations of silicone implants. Publications relative to those implants showed that the survival rates after 5 years of follow-up were unsatisfactory. Since 1998, Tornier has been selling a new generation of silicone implants made of Ultrasil™. The use of this new material in its manufacturing process together with its innovative geometry, make the Primus™ FGT a much more resistant, anatomic and long lasting implant. The main objective of this study is to evaluate the clinical outcomes of the implantation of Primus™ FGT implant in great toe arthroplasty. The study will capture long term outcomes in terms of functional metrics from documented clinical data. Other objectives are to evaluate the outcomes in terms of radiological evaluation and of safety during all the follow-up.

Detailed Description
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This is an observational post-marketing surveillance study, performed by 1 (one) investigator in 1 (one) Italian site. Preoperative and peroperative data were collected retrospectively. Postoperative data (minimum 5 years follow-up or until implant revision) were collected prospectively.

Official Title
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A Post-Market Observational Study to Evaluate Safety and Performance of Primus™ FGT Implant at a Minimum of 5 Years Follow-up

Conditions
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Osteoarthritis, Hallux Limitus of Left Great Toe, Rheumatoid Arthritis, Arthritis of 1st Metatarsophalangeal Joint, Bunion, Hallux Limitus of Right Great Toe

Intervention / Treatment
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* Device: Primus FGTI (Flexible Great toe Implant)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patient has had a Primus™ FGT implantation for one of the following indications: hallux limitus, hallux rigidus, hallux abducto valgus associated with severe arthritis, unstable or painful joint from previous surgery on the great toe, patient having all necessary clinical and radiographical data available., patient has been informed about this scientific study and has provided their Consent to participate. Exclusion Criteria: patient does not have clinical and radiographic follow-up data available.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: Primus FGTI (Flexible Great toe Implant)|Great toe arthroplasty consists of replacing the first Meta-Tarso-Phalangeal (MTP1) joint by a two hinged prosthesis made of silicone : the Primus FGT implant (FGTI). The Primus is designed with an axially offset hinge to align with the anatomy of the MTP joint. This results in less implant stresses and improved toe function.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| AOFAS Hallux-MTP-IP Score - Overall | AOFAS (American Orthopedic Foot and Ankle Society) Hallux-MTP-IP (Hallux-Meta-Tarso-Phalangeal-Inter-Phalangeal) score is composed of 3 sub-scores : (i) Pain score is ranging from 0 to 40 points ; Function score is ranging from 0 to 45 points ; Alignment is ranging from 0 to 15 points. The AOFAS total score is then ranging from 0 to 100 points. A result over 80 points is considered good, below 20 points as bad. | mean 6.9 years follow-up (range 5.2 - 9.5) | 
| AOFAS Hallux-MTP-IP - PAIN Score | Pain is a sub-score of the AOFAS Hallux-MTP-IP score and is measured on a scale of 40 points - the higher value represents a minimal pain. | mean follow-up of 6.9 years (range, 5.2 - 9.5) | 
| Pain at Passive Motion of MTP1 | Number of patients reporting pain at passive motion of MTP1 at preoperative and postoperative visits. | mean follow-up of 6.9 years (range, 5.2 - 9.5) | 
| Pain at Pressure of MTP1 | Number of patients reporting pain at pressure of MTP1 at preoperative and postoperative visits. | mean follow-up of 6.9 years (range, 5.2 - 9.5) | 
| Walking Perimeter | Subjective evaluation by the patients of their walking perimeter, postoperatively versus preoperatively. Patient had to choose among 3 variables : improved, same, worsened. | mean follow-up of 6.9 years (range, 5.2 - 9.5) | 
| Pain During Walking | Subjective evaluation by patients about pain during walking, postoperatively versus preoperatively. Patients had to choose among 4 variables : disappeared, less, same, greater. | mean follow-up of 6.9 years (range, 5.2 - 9.5) | 
| Pain at Rest | Subjective evaluation of patients about ther pain at rest, postoperatively versus preoperatively. Patients had to choose among 4 variables : disappeared, less, same, greater. | mean follow-up of 6.9 years (range, 5.2 - 9.5) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Osteolysis | Osteolysis evaluation was described as : absent or present. Radiological evaluations were done from available frontal and lateral view X-rays. | mean 6.9 years (range, 5.5 - 9.5) | 
| Bone Resorption | Bone resorption evaluation was described as : absent or present. Radiological evaluations were performed from available frontal and lateral view X-rays. | mean 6.9 years (range, 5.5 - 9.5) | 
| Survival of the Implant. | The survival of the implant is evaluated according to the number of implant revisions or of reoperations, whatever the reason. | mean follow-up of 6.9 years (range, 5.2 - 9.5) |