What are Activa implants?
They are orthopaedic implants made of bioabsorbable materials. In the early stages of bone healing, bioabsorbable implants preserve fixation. With the passage of time, the implant gradually decomposes and the stresses are gradually transferred to the healing tissue. The implant absorbs in vivo by hydrolysis into biocompatible absorption products, which are metabolized in the body.
Why to use Activa implants?
Bioabsorbable Activa implants offer temporary support for the body to allow healing of damaged tissue and disappear after the fixation task is completed, leaving tissue without any foreign material present. The main benefit is that the tissue has a temporary help but it gets its original task and challenge back and thus the original function and anatomy of human skeleton is respected. Bioretec Activa implants include these traditional advantages, but also offer advantages to surgeons when compared to traditional bioabsorbable and metallic implants.
Do Bioretec's Activa implants offer advantages for the patient?
Yes. In a number of cases, traditional metallic implants have to be removed due to e.g. movement limitation, pain, irritation, palpability, patient sensitivity or imaging interference. Bioabsorbable implants overcome these issues. Stress shielding associated with metallic implants may result in bone atrophy and osteoporosis. As bioabsorbable implants resorb, they gradually transfer loads to the healing bone, assisting in the healing process. Due to the implant absorption, the risks of implant-related long term complications are eliminated. If given a choice, patients often prefer a biodegradable implant to the one that permanently remains in their body or alternatively requires a second surgery, a removal procedure.
Do Bioretec Activa implants offer advantages for the surgeon?
Yes. Due to their mechanical properties and mechanical activity Bioretec Activa implants feature beneficial properties which are not available with metallic implants. The implants show a Self-Locking™, property due to diameter expansion of the implant. The Auto-Compression™ means longitudinal contraction of the implants with a controlled force. This feature helps in maintaining sufficient compression in the healing tissue throughout the healing. The bending modulus of Activa implants is closer to that of bone than bending modulus of metallic implants. Due to this modulus match with bone the fixation does not cause stress shielding, which could have a negative impact to the quality of the bone in the fixation area.
What properties make absorbable implant safe to use?
Material for a particular Activa product is chosen respecting the surgical target (indication), physical forces in the targeted area and the rate of the healing process in the related area. The selection of the material, however, is only one of the several parameters affecting the implant function and safety. The properties like strength, fracture behavior, degradation time and mechanical activity are defined in in-house developed manufacturing processes.
The common demands for a bioabsorbable implant are:
a. High Initial Strength
The implant must resist mechanical stresses during surgical procedures and it must carry external and physiological loads during the early stages of healing when the healing tissue/bone is still weak.
b. Appropriate Initial Modulus
The material must not be too stiff or too flexible for the special purpose it is used for. Modulus of the fixation material should be close to the modulus of the material (bone) under repair for the best biomechanical performance. If the modulus is too low, the implant does not support enough the healing tissue and if it is too high, there’s a high risk of stress shielding (delayed healing and/or bone weakening).
c. High Initial Toughness
The practical value of an implant material is rated during the surgery. Brittle materials are difficult to work with because they crack without a warning. Materials of Activa implants are tough meaning a benefit of feeling the deformation of the material, thus offering safe insertion and good handling properties.
d. Controlled Strength Retention in vivo
Optimally the loss of strength and modulus in vivo is in conformity with the increase of strength and modulus of the healing tissue (bone).
e. Controlled Absorption in vivo
Tailored processing methods and rigorously adjusted processing and material parameters guarantee optimal and controlled bioabsorption of Activa implants. The complete bioabsorption of the Activa implants lasts approximately 2 years.
What happens to the Activa implant as it resorbs?
The implants degrade by hydrolysis forming lactic acid and glycolic acid as intermediate products and finally are metabolized into carbon dioxide and water by human cells, which are then exhaled and excreted.
What materials are Bioretec Activa implants constructed of?
The Bioretec Activa implants are made of poly-L-lactide-co-glycolide polymer. The monomers, the construction units of PLGA are L-lactic acid and glycolic acid, which are part of the normal chemistry of mammalian cells.
Why was this material selected?
From a chemical point of view, the medical grade poly L-lactide-co-glycolide copolymer (PLGA) used in the Bioretec Activa product line does not contain components which could negatively affect the biocompatibility of the product. The monomers of PLGA are l-lactic acid and glycolic acid, which are part of the normal chemistry of mammalian cells. PLGA copolymers overcome historical problems related to too rapid degradation of PGA material and too slow degradation of PLLA material by utilizing a combination of the degradation properties of both polymers.
Is there clinical proof that this material is safe?
Yes. The PLGA material used in the manufacturing of Bioretec Activa implants has a long history of safe clinical use, and has been shown to be biocompatible in both animal and clinical evaluations.
What is the difference between PGA, PLLA and PLGA bioabsorbable implants?
PGA implants are reported to lose mechanical strength in 4 to 6 weeks in vivo, while PLLA implants are reported to lose mechanical strength in 4 to 6 months. Bioabsorption of PGA material takes place within approximately 1 year, whereas crystalline remnants of PLLA have been found in tissue 4 to 5 years after implantation. By copolymerizing the PGA and PLLA the material properties can be tailored to fit the desired indication. Bioretec implants are made of PLGA. They maintain their mechanical strength at least up to 8 weeks and bioabsorb within approximately 2 years. In addition to the material composition, the manufacturing method of bioabsorbable implants has a remarkable effect on the strength, toughness and the hydrolytic degradation of the material. The advanced manufacturing technology employed to create Bioretec Activa implants delivers high strength, toughness and predictable, controlled strength to the bioabsorption properties.
New RemeOs™ Implants
What materials are Bioretec RemeOs™ implants constructed of?
RemeOs™ implants are made of unique bioresorbable metal alloy constructed from Magnesium, Calcium and Zinc, which are all essential elements of new bone formation in human body. Noteworthily RemeOs™ does not contain any materials foreign to human body like Yttrium, Gadolinium, Neodymium nor any other rare-earth elements (REE).
What are the main differences between the Activa implants and the new Bioretec RemeOs™ implants
Bioretec RemeOs™ implants and Activa implants are both biodegradable implants. Since RemeOs™ is a metallic material, it has metallic properties as well i.e. higher strength, rigidity and hardness than Activa implants. Higher mechanical properties allow novel surgical techniques with the RemeOs™ implants and they can be used in indications where higher strength and rigidity is required.
What happens to RemeOs™ implants as they resorb?
RemeOs™ implants resorb through oxidation to Magnesium-, Calcium- and Zinc-minerals, which are all essential elements of new bone formation in human body. Resorption initiates on the surface of the implant and the implant’s dimensions start to decrease gradually. The osteoconductive effect of the resorption minerals induces new bone formation which happens simultaneously with the implant resorption. This ensures firm connection between the implant and the bone during the entire healing period.
What are the advantages of RemeOs™ implants for the patient?
The resorbable metal alloy used in RemeOs™ implants does not contain any rare-earth elements (REE) or rare-earth metals (REM), such as Gadolinium (Gd), Yttrium (Y) or Neodymium (Nd) and others. The patient does not have to worry about the long-term effects of these rare-earth elements and their possible negative reactions in the body. According to our pre-clinical studies, the RemeOs™ material is well suitable for paediatric patients, since it is constructed only from Magnesium, Calcium and Zinc, which are all essential elements of new bone formation in human body.
In many cases, traditional metal implants have to be removed due to e.g. movement limitation, pain, irritation, palpability, patient sensitivity or imaging interference. Removing surgery increases patient’s discomfort and risk of complications. RemeOs™ implants eliminate the need for implant removal. Stress-shielding associated with traditional metallic implants may result in the bone atrophy and the osteolysis. Bioresorbable RemeOs™ implants resorb to bone, assisting in the healing process. Due to the implant resorption, the risks of any implant-related long-term complications are eliminated.
What are the advantages of RemeOs™ implants for the operating surgeon?
Now for first time surgeons have the possibility to use safe bioresorbable materials in high load-bearing indications. Strength of RemeOs™ implants is close to traditional (stainless steel, titanium) metal implants. With the new RemeOs™ implants surgeon can achieve similar fixation as with traditional metal implants. Also operation technique principles with RemeOs™ implants are same as with traditional metal implants. According to our pre-clinical studies, the RemeOs™ material is safe and well suitable also for paediatric patients. The Magnesium alloy used in the material is constructed only from Magnesium, Calcium and Zinc, which are all essential elements of new bone formation in human body.