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Fixation of Malleolar Fracture Using ActivaScrew™

Esa Partio M.D., Ph.D.

The Patient was an 18 years old male, with high energy snowboarding injury. Preoperative X-ray revealed dislocated Weber B - type fracture with rotational malposition. Ankle mortise widening was also evident based on the preoperative X-ray showing total deltoid ligament torn. The fracture was fixed with two fully threaded ActivaScrew™ 4.5 x 50 mm bioabsorbable screws. As a postoperative immobilization, a functional brace was applied. Partial weight-bearing was allowed at 3 weeks and full weight-bearing at 6 weeks The functional result of the operation was excellent.

ID: WP01
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Fixation of Malleolar Fracture Using ActivaPin™

Esa Partio M.D., Ph.D.

 

The patient was a 58 years old normal female, with Weber A -type lateral malleolar fracture. Primary treatment conservatively with 6 weeks plaster cast immobilization and nonunion of the fracture. Two ActivaPin™s were used in angle to create rigid stability and compression to the fragment line. The fracture healed well with exact position and pain in the ankle was relieved. A nonunion after failed conventional treatment of a Weber A-type malleolar fracture was successfully treated with two ActivaPin™s.

ID: WP02
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ActivaScrew™ Interference Comparison to PLLA Based Competitors

Bioretec Ltd.

ActivaScrew™ Interference is manufactured from PLGA (85% L-lactide/15% Glycolide). This composition gives ideal absorption properties. ActivaScrew™ Interference`s unique manufacturing technique provides very high initial mechanical properties and produces Self-Locking SL™ feature. Self-Locking SL™ is based on screw diameter change (up to 7%) during first weeks after surgery. In this paper, data is compared with PLLA products used by e.g. Arthrex and Conmed.

ID: WP03
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First Metatarsophalangeal Arthrodesis Using ActivaScrew™ Cannulated LAG

Heikki Mäenpää M.D., Ph.D

67 years old female patient with severe hallux valgus in the right foot causing pain and severe limitation of physical activity. First hallux valgus angle (HVA) of 50? and the age of the patient suggest MTP I arthrodesis. MTP I arthrodesis was carried out using one 3.5 x 40 and one 3.5 x 45 mm ActivaScrew™ Cannulated LAG. The perioperative visual and fluoroscope view of the foot showed good alignment and well compressed joint surfaces. Appropriate position of the first MTP joint was achieved (15 degrees of valgus and 20 degrees of dorsiflexion). A compression dressing was applied to support and protect the foot during the first days after the operation. The patient was instructed to wear a hallux valgus shoe and avoid full load-bearing on the foot for the first 6 postoperative weeks. At 6 weeks X-ray showed bony fusion of the MTP I joint. Full weight-bearing was started gradually and the patient could go back to normal activity level within the next few weeks. The patient was allowed to start bearing exercise three months after surgery.

ID: WP04
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Hallux Valgus Correction Using ActivaPin™ and ActivaNail™

Heikki Mäenpää M.D., Ph.D.

 

The patient was 43 years old female with a medical history of spondyloarthropathy, obesity and fibromyalgia. Preoperative X-ray examination showed mild osteoarthritis of the first MTP joint with hallux valgus angle (HVA) 29 ? and intermetatarsal angle (IMA) 15 ?. Metatarsalgia and osteoarthritis of the second metatarsal head was caused by the osteochondritis as a consequence of the Freiberg’s disease. The left foot had hallux valgus angle (HVA) 18 ? and intermetatarsal angle (IMA) 12 ?. In order to relieve the pain and restore the normal anatomy of the foot, operative treatment was decided with chevron osteotomy using ActivaPin™ for the first metatarsal head and soft tissue reconstruction. In addition, Weil osteotomy was decided to be carried out on the second metatarsal with ActivaNail™ as a decompressive procedure. Postoperatively, stable osteotomies were seen in the fluoroscopy picture as well as hallux valgus correction of the MTP I joint and decompressed MTP II joint. Hallux valgus angle (HVA) was 23 ? and intermetatarsal angle (IMA) 13 ?. ActivaPin™ and ActivaNail™ are well suitable for fixation of chevron, Weil and many other osteotomies in foot surgery.

ID: WP05
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Clinical Application of PLGA Resorbable Screw Fixation in Forefoot Surgery

Charles M Zelen, DPM FACFAS, David L Nielson, DPM

A screw which is a mixture of 85% Poly-Lactic Acid and 15% Poly-Glycolic Acid gives a high mechanical and shear strength, as well as stiffness, while delivering reliable resorption characteristics. A 40-year-old health care worker with a long-standing bunion deformity failing conservative care for many years, elected for a bunionectomy. The patient underwent a long arm chevron bunionectomy with a hallux osteotomy. The patient spent two weeks in a splint and then transitioned to a cam-walker and returned towork at the hospital weightbearing in the cam walker. After six weeks she went into tennisshoes, then returned to full activity shortly after and returned to her exercise regimen by week 12. The patient had no incidence of any type of inflammatory soft tissue reaction, nor wasthere any osteolysis seen on x-ray on long term follow up. Tornier´s RFS screw used in the case was manufactured by Bioretec.

ID: WP06
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Syndesmosis Fixation Using ActivaScrew™ in Three Weber C -Type Ankle Fracture Cases

Tero Järvinen M.D., Ph.D.

 

Three cases: two bimalleolar Weber C-type ankle fractures and one trimalleolar Weber C-type ankle fracture, where surgeon successfully combined the use of conventional metallic AO-plates and -screws with the biodegradable syndesmosis screw (ActivaScrew™ 4.5 x 70 mm) to fix the ruptured syndesmosis. Post-operative protocol and follow-up: Short cast for 6 weeks (skin suture removal on day 14); Weight-bearing protocol: 3 weeks no weight-bearing, + 2 weeks partial (half) weight-bearing + 1 week of full weight-bearing with the cast. At 6 weeks: Cast removal, X-rays and clinical examination.

ID: WP07
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Conclusion Study For Absorbable ActivaPin™ - 50 cases with 2 years of follow-up

Docteur Hubert ROCHE

The study included 50 cases of hallux valgus surgery on 43 women and 7 men. The surgeries consisted of a minimally invasive distal dynamic metatarsal osteotomy in all cases, associated with phalangeal osteotomy. The average age was 56 years and 1 month. Preoperative score (AOFAS Classification) was 48. Postoperatively the average AOFAS score was 92.

ID: WP08
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First Metatarsophalangeal Joint Arthrodesis Using ActivaScrew™ Cannulated

Dr. Nikke Partio, Orthopedic Trauma Surgeon.

 

This case report describes the first metatarsophalangeal joint arthrodesis using bioabsorbable cannulated screws as a viable alternative method. The patient was a 58-year-old woman with a hallux valgus deformity on the right extremity with persistent pain and swelling for years. Non-surgical treatments, such as anti-inflammatory medication, shoe modifications, silicone brace, and physiotherapy, were ineffective. Because these conservative measures failed, operative treatment was chosen. . Dorsiflexion was 15° and plantar flexion was 20°. X-rays revealed MTP-1 arthrosis. The hallux valgus angle was 33° and the intermetatarsal angle was 22° (Figs. 1,2). The preoperative AOFAS - Hallux Metatarsophalangeal Interphalangeal score was 47. Two bioabsorbable cannulated screws (30 mm and 35 mm) were used. A cast boot with an 8° ankle dorsiflexion outsole to transfer walking pressure to the rear foot was used for 6 weeks postoperatively. Full weight-bearing was allowed immediately. The AOFAS score was 76 at the 12-month visit and remained as 76 at the 24-month follow-up.

ID: WP09
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Fixation of Osteochondritis Dissecans (OCD) Lesions Using ActivaPin™s

Tero Järvinen M.D., Ph.D.

The patient was an 18-year-old male and an active football player with osteochondritis dissecans lesion in the medial femoral condyle. There was a loose OCD with fluid between the fragment and the main bone, caused a flexion and extension deficit, ROM 5-135. This difficult OCD was fixed with 8 ActivaPin™s. In the six-month follow-up complete osteointegration of OCD fragments, no fluid between the fragments and active remodelling. ActivaPin™ is very easy and convenient to use in OCD fragment fixation. Self-Locking SL™ feature provides outstanding locking of the material as well as compression at the fracture line that is crucial for small fragment fixation.

ID: WP10
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Fixation of Osteochondritis dissecans (OCD) Using ActivaPin™ and Arthroscopic Pin Applicator

Esa Partio M.D., Ph.D

The patient was a 15 years old sports active male, with diagnosed Osteochondritis dissecans (OCD) in the right knee. In a clinical examination in addition to OCD pain was noted around the popliteal tendon at the posterior side of the knee. Operative treatment of the OCD lesion was decided to fix with two ActivaPin™ 2.0 x 30 mm implants, inserted slightly non-parallel to achieve good stability to the fixation. The X-ray evaluation at 2 months postoperatively revealed a stable OCD fragment. Result of the operation was good and the patient was able to continue his semi-professional sports activities.

ID: WP11
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Fixation of Patella Fracture Using ActivaPin™and ActivaScrew™

Esa Partio M.D., Ph.D.

The patient was an 18 years old sports active male. The fracture of patella occurred while playing badminton due to subluxation of the patella. In the preoperative X-ray and MRI, a dislocated 26 x 15 mm fracture was found at the medial side of the patella. In addition to that main fragment, loose osteochondral fragments were found around the main fracture. The main fragment was fixed using one ActivaScrew™ 4.5 mm fully threaded and a loose osteochondral fragment was fixed using two ActivaPin™ 2.0 mm. The patient was able to return to normal sports activities 6 weeks postoperatively.

ID: WP12
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Fixation of the tibial condyle fracture with ActivaScrews™

Prof. Dr. Alexandr Shuginov and Dr. Aleksandr Nikitin Orthopaedic surgeons

The patient is a man, 47 years old, with a car accident trauma. Preoperative X-ray revealed a fracture of the lateral condyle of the left tibia with a displacement of the fragments and a fracture of the distal metaepiphysis of the left radius with a displacement of the fragments The fracture in the lateral condyle of the left tibia was decided to surgically fix with bioabsorbable ActivaScrew™s. For the postoperative immobilization plaster splints were applied for 6 weeks with no weight-bearing, followed by two weeks partial weight-bearing and after week 8 full weight-bearing.The postoperative period was normal with excellent clinical and radiological results.

ID: WP13
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LCL Reconstruction Using ActivaScrew™ Interference

Tero Järvinen M.D., Ph.D. Professor, Chief Surgeon

 

The patient was 31-year old healthy female, who had injured her left knee in ultimate fighting-training. A total, grade III, isolated rupture of the lateral collateral ligament (LCL) was suspected based on the clinical examination. Open LCL reconstruction using modified LaPrade-technique and bioabsorbable interference screws was carried out. Two ActivaScrew™ Interferences were used for the fixation. The patient had experienced no setbacks in her post-op regimen at the 8 months’ follow-up. She had returned to full ultimate fighting (competitive) training before the 6-month follow-up without any symptoms.

ID: WP14
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Patellar Osteochondral Fragment Fixation Using ActivaPin™ - 11 Year-old Child

Juha-Jaakko Sinikumpu M.D., Ph.D. Pediatric Orthopedic Surgeon

The patient was an 11-year old female who fell while bicycling and injured her right knee. It was a rotational motion injury, resulting in the development of a large oedema and tenderness. Other key clinical finding was a decreased range of motion of the knee: Flexion range was restricted to45-40 degrees. In the primarily radiographs a loose bone fragment was seen in the knee joint. The CT showed that the fragment was originating from a stress-bearing area, the distal apex of the patellae. No other acute musculoskeletal findings were seen in the CT. Arthrotomy was necessary due to the small dimensions of the child patient, instead of arthroscopy guided fixation. The fragment was fixed with three ActivaPin™s. In the follow-up radiographs, the loose bone part was ossifying. The patellar joint surface looked smooth. The knee was symptomless, stable and the range of motion (ROM) was normal.

ID: WP15
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ACL Re-Rupture Fixation Using ActivaScrew™ Interference

Tero Järvinen M.D., Ph.D.

The patient was a 29 years old male, who had a left knee trauma and a total ACL rupture six years earlier. ACL re-rupture diagnosis was confirmed by the MRI. The operative plan was to perform single-bundle ACL revision reconstruction using hamstring-tendons from contralateral leg and ActivaScrew™ Interference screws for the fixation of the graft. Femoral fixation was carried out with ActivaScrew™ Interference screw (8 x 24 mm) and tibial fixation was carried out with ActivaScrew™ Interference screw (9 x 30 mm). The patient was very satisfied with the outcome of the ACL revision surgery and Full ROM was achieved (ROM 0-140).

ID: WP16
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Fixation of Tibial Plateau Fracture Using ActivaScrew™ Cannulated - 11.5-Year-old Child

Dr. Stephane Tercier M.D. Pediatric Trauma Surgeon

The patient was 11.5-year old male, with diagnosed right proximal tibia fracture, type Salter-Harris 3 of the external epiphysis. Proximal tibia external arthrotomy was needed. Hemarthrosis washout, Anteromedial meniscocapsular tear needed outside-in suture. Tibial fracture reduction and stabilization with 2 metallic pins and fixed with, two ActivaScrew™ Cannulated screws (40x40 mm and 40x35 mm). Result of the procedure was excellent, X-ray investigation was carried out to evaluate the stability of the proximal tibia fracture. The X-ray evaluation revealed appropriate bone healing and the patient could totally return to sports in 4 months.

ID: WP17
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Salter Osteotomy Using ActivaScrew™ Cannulated - 3 Year-old Child

Tero Laine M.D., Ph.D

The patient was a 3 years old child with congenital dislocation of the hip. Patient’s left side hip has been operated 4 months ago using K-wires. The right side hip was now operated with Salter osteotomy. The osteotomy and the bone graft wedge were stabilized with two 1.6mm K-wires under fluoroscopy. Two fully threaded 4.5 mm ActivaScrew™ Cannulated were inserted along the K-wire. The K-wire was removed and the screw was cut with the hotcautery along the bone surface. The ActivaScrew™ Cannulated can be used in the Salter Osteotomy to overcome the problems with the use of K-wires. No migration, pin tract infections or removal operation which makes the use of ActivaScrew™ Cannulated more comfortable to the patients.

Read more about the related study: MRI evaluation of resorbable poly lactic-co-glycolic acid (PLGA) screws used in pelvic osteotomies in children - a retrospective case series

ID: WP18
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Humeral Head Reconstruction using ActivaScrew™ and ActivaPin™

Dr. Gábor Skaliczki, M.D. Ph.D, Dr. Kovács, M.D

The patient is a 26-year old male, with a proximal humeral head fracture with a posteriorly dislocated 30 x 35mm fragment in a car accident. On physical examination seriously limited range of motion was observed, the AP radiograph showed incongruent humeral joint surface. Reconstruction of the humeral head was performed with ActicaScrew™ and ActivaPin™ and restoration of the humeral joint surface was established. ActivaScrew™ is a suitable tool for intra-articular fixation of large fracture fragments. Additional ActivaPin™ can be used for enhanced rotational stability.

ID: WP19
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Possibilities of Calcaneus Fracture Osteosynthesis with Cannulated PLGA Screws

Linnik S. A., Shuginov A.A., Nikitin A.V.

39 patients with Calcaneus fractures were treated. 70% of the patients were young and middle (employable) age. 34 patients were operated, 2 patients withdrew from the operation, 3 patients – conservative treatment after closed reposition of fracture.The main indication for treatment is the preservation of the Böhler angle as well as the relocation of posterior facet fragments for less than 2 mm. Presence of such co-existing pathologies as peripheral vascular disease, infectious diseases and diabetes are also taken into consideration. The hospital treatment period was 1-2 days before and 3-6 days after the operation.

Advantages found were: No need for re-operation to remove implants. Gradual resorption offers the possibility to activate bone union process by gradually growing weight-bearing in a fracture zone, thereby creating the best conditions for biomechanical bone remodelling. Self-compression characteristics reduce the risk of unstable fixation. Isoelasticity: flexibility module is closer to bone compared to metal implants. -Absence of stress-shield due to the gradual reduction of tension in the bone. Implants are delivered sterile in an individual package that reduces the risk of cross-infection.

ID: WP20
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Mini-invasive biodegradable PLGA osteosynthesis in the treatment of children’s distal tibial fractures

N.Yu. Serova, S.O. Nikishov, D.Yu.Basargin, A.M.Lushnikov, S.V. Sidorov, M.K.Tishenko, D. A. Vorobyev - Traumatology department, Children’s Clinical and Research Institute of Emergency Surgery and Trauma, Moscow, Russia

36 operations were done on children with fractures in the epiphysis area. All intraoperative X-ray revealed satisfactory standing of the fragments, external immobilization was not needed. Radio-graphic examination showed the satisfactory standing of fracture fragments, revealed stable ostheosynthesis. No complaints, no generalized or local reaction were mentioned the early postoperative stage. The average hospital stay was 10 days; children were discharged from the hospital in satisfactory condition, non weight-bearing with crutches, with full range of motion in related joints. Full weight-bearing was allowed after the X-ray investigation 30-40 days after the surgical treatment. Fracture union took place within the established age time limits. On the follow-up visits after 3 weeks, 6 months and 1-2 years there were no complaints; children were not limping; they had full range of motions in the joints; no local reaction on the clinical examination and ultrasound investigation was mentioned.

There were no complications, such as dislocation of bone fragments, implant migration, fracture union delay, inflammation and stiffness in the damaged joint or local reaction to the implant during the period of study follow-up.

ID: WP22
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Biodegradable Implants in Treatment Of Chronic Posttraumatic Anterior Shoulder Instability With Bone Defect of Scapula Articular Process

Vasily V. Monastyrev, Vyacheslav Y. Vasilyev, Marina E. Puseva, Nikolay S. Ponomarenko, Irkutsk Scientific Centre of Surgery and Traumatology, Irkutsk, Russia

The aim was to assess the effectiveness and safety of biodegradable implants in the treatment of chronic post-traumatic anterior shoulder instability under conditions of glenoid cavity margin bone defect of more than 20 % of scapula articular surface. The study of using modern biodegradable implants in osteoplastic stabilization of shoulder joint with bone defect more than 20 % of scapula articular surface showed its effectiveness and safety.

ID: WP26
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Biomechanical pull-out test between Synthes LAG screws, Bioretec ActivaScrew™ LAG and Bioretec ActivaScrew™ with porcine fibula

Bioretec Ltd.

The purpose of this study was to investigate and compare the biomechanical pull-out force of metallic screw fixation and bioabsorbable screw fixation of acromioclavicular joint. The fixation is necessary for severe separations of fixation of the acromioclavicular joint. The common surgical practice, the Bosworth screw fixation, was selected as a surgical technique. The test demonstrated that the bioabsorbable 4.5 mm ActivaScrew™ give similar pull-out force in a simulated acromioclavicular joint fixation when compared to metallic 6.5 mm LAG screw. The ActivaScrew™ LAG shows the best results of all the screws in the test. 

ID: WP27
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Bioretec ActivaPin™ and ActivaNail™ material compared to CONMED Smartnail®

Bioretec Ltd.

PLGA, the material used in ActivaNail™ and ActivaPin™ has low crystallinity on contrary to 96L/4D, PLA, which has high crystallinity. Other differences in the SmartNail® are the long absorption time, the possibility of implant capsulation leading to possible increased risk of re-injury and the design of the implant. The Self-Locking SL™ property of ActivaNail™ and ActivaPin™ further improves the pull-out performance, by the diameter increasing 1-2% in human bone.

ID: WP28
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Fracture of the Greater Tuberosity of the Humerus, Fixation with ActivaScrew™s Cannulated

M.D. Aleksandr Nikinin, Orthopedic Trauma Surgeon.

The patient was a 54-year-old woman with a displaced fracture of the greater tuberosity of the left humerus. Bone fragments were repositioned through a deltoid split approach to the humerus. The fracture was fixed with two 3.5 mm x 45 mm bioabsorbable ActivaScrew™s Cannulated with partial thread. For postoperative immobilization,a scarf bandage was applied. Passive shoulder joint and elbow joint exercising was approved after 4 weeks for two weeks. In this phase the patient takes off the scarf bandage 5-6 times a day and starts to exercise the elbow joint and bending and abducting the shoulder joint to 90° in a passive mode. After the two week period, at week 6, the patient started more active exercises. The course of the postoperative period was normal with excellent clinical and radiologic results. After 6 years, the patient was called for a follow-up examination. CT scan was performed for an accurate assessment of fracture consolidation and bone canal condition.The patient was pain-free and could do all the activities of daily life. The CT scan shows that screws were completely resorbed, and the canal is filled with bone.

ID: WP29
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Fixation of the Patella Fracture using ActivaScrew™ Cannulated

M.D. Alexandr Nikitin Orthopedic Trauma Surgeon

61-year-old woman, active with sports, got injured with a displaced patellar fracture. The fracture was fixed with 2 biodegradable ActivaScrew™ Cannulated 4.0 x 50 mm fully threaded screws. After week 6, control radiographs showed the correct position of the fragments and consolidation. As an end result the range of motion was as before and the patient can live without any pain.

ID: WP30
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Bioabsorbtion of Bioretec Activa™ implants

Bioretec Ltd.

Oriented PLGA (poly(lactic-co-glycolic acid) polymer is a very strong and tough material. Therefore it is suitable raw material for manufacturing of bioabsorbable implants. Final bioabsorption takes 1 to 2 years in vivo, depending on implant size, geometry and tissue metabolism conditions at the implantation site. After implantation Bioretec Activa -implants increase in diameter and decrease in length 1-2 % during first postoperative weeks as a consequence of water absorption and structural relaxation of the oriented molecular structure. These dimensional changes lock the implants effectively into bone. The contraction of the implant in length applies a predetermined stress to the healing tissue ensuring the firm contact and advantageous compression in the fracture or osteotomy line.

The absorbed water starts the hydrolysis of the implant material. This can be seen as the reduction of molecular weight and strength of the implant as a function of hydrolysis time. In Vitro the visual appearance of the implant turns from transparent to whitish indicating degradation of the material. After 6 months of in vitrohydrolysis the material is still solid, but pieces of the implant can be fractured off the surface by using a substantial force. After 1 year of in vitro hydrolysis the Activa –products are already weak and porous. They can be broken to powder or to small granules when pressing with a finger. After two years of in vitro hydrolysis only small amount of powder or small granule-like material is left of Activa –products. Final bioabsorption takes 1 to 2 years in vivo, depending on implant size, geometry and tissue metabolism conditions at the implantation site.

ID: WP31
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Bioretec Activa™ Biocompatibility Information Package

Bioretec Ltd.

From the chemical point of view medical grade poly L-lactide-co-glycolide copolymer (PLGA) used in Bioretec´s orthopaedics and traumatology products do not contain components, which could negatively affect the biocompatibility of the material. The monomers of PLGA are part of the normal chemistry of mammalian cells.

ID: WP32
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Fixation of physeal fractures with bioabsorbable implants

Bioretec Ltd.

The advantage of the bioabsorbable device fixation in physeal fractures of children is that a second procedure for hardware removal is not required. According to general instruction, crossing the physis with any form of fixation should be avoided, if possible. However, according to literature, if the fixation of physeal fractures by crossing through the growth plate is demanded, fixation with small bioabsorbable pins can be safely done without significant growth disturbance, as the size of the pin remains 3 % or less of the total cross-sectional area of the growth plate. However, the effect of ActivaPin™ or ActivaScrew™ upon the healing of the growth plate has not been tested in clinical studies.

ID: WP35
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Comparison between ActivaScrew™ and titanium compression screws: biomechanical compressional force and force relaxation after implantation

Bioretec Ltd.

The biomechanical compressional force test for 4.5 mm ActivaScrew™LAG demonstrates that it is possible to achieve similar compressional forces with the ActivaScrew™ as with the metal screws. The foam model comparison of 3.5 mm ActivaScrew™ to Synthes 3.5 mm cannulated metal screw or metallic headless compression screws of similar size from Bailey et al. study support this observation. The maximum compression for 3.5 mm ActivaScrew™ was 54 N where it was 20 N –38 N for the metal screws of similar size in the similar test setup; Acutrak 38 N, Asnis 33 N, Little Grafter 32 N, Herbert 22 N and Herbert Whipple 20 N.

The ActivaScrew™ achieves similar compressional forces as the metal screws. ActivaScrew™ holds the compression better than the metal screw after achieving the stabilized compression level.

ID: WP36
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Physeal Fractures and Bioabsorbable Implants - Literature review

Bioretec Ltd.

Literature review on the physeal fractures with classifications and literature findings. Pediatric physeal fractures are traditionally described by the Salter-Harris classification in which displaced fractures of types III and IV often require open reduction and internal fixation in order to integrate intra-articular disruptions.

ID: WP34
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Treatment of medial malleolus fracture in skeletally immature patient with bioabsorbable screws

Dolnák, A., Béder, I., Sýkora, L., Jáger, R., Haas, I. Pediatric Trauma Center, Dpt. of Pediatric Surgery National Institute of Children’s Diseases, Bratislava, Slovakia Pharmacare Slovakia, s.r.o.

Fractures around immature ankle are relative common. In the literature, the incidence is approximately 5% of all skeletal fractures. (58, 68) The physeal growth plate is an important structure and deserves special attention. Complete distal tibia epiphysis closure can be observed between 12-17 year of age. In consideration of this we can find several types of injuries typical for childhood (physeal injuries), adolescent or transition age (Tillaux, Triplane fractures) and subsequently adult-like fractures (bimalleolar, trimalleolar fractures) Keywords bimalleolar fracture, adolescent, surgical treatment, bioabsorbable screw.

ID: WP37
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Bimalleolar ankle fracture fixation of a 13-year-old patient with two ActivaScrew™ LAG bioabsorbable screws.

Pierre Lascombes, Professor, M.D., Ph.D.

13 years old girl presents with a fracture dislocation of the right ankle joint following a gymnastic fall. Lateral malleolus fracture is mainly a Salter-Harris type I, as medial malleolus fracture is mainly a Salter-Harris type IV. Both fractures present with some communitive small fragments, also a persistent talo crural subluxation. She had two ActivaScrew™ LAGs. Imaging control showed that the fracture line completely disappeared, proof of an excellent reduction. An immediate arthrogram of the ankle joint confirmed the excellent reduction of both fractures Three months later, the range of motion of the right ankle was comparable with the left one and the girls was able to practice most of sports activities like before.

ID: WP38
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RemeOs™ material

Bioretec Ltd.

RemeOs™ implants are made of unique and patented 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 norany other rare-earth elements (REE). 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.

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.

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.

Now for first time surgeons have the possibility to use safe bioresorbable materials in 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, there is no need to make threads for the RemeOs™ screw. 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.

ID: WP41
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Activa™ material

Bioretec Ltd.

Activa™ implants 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 absorbs 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. In several 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 osteolysis. As bioabsorbable implants absorb, 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 requires a second surgery, a removal procedure.

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 SL™ 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.

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.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). 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. Optimally the loss of strength and modulus in vivo happens simultaneously with the increase of strength and modulus of the healing tissue (bone). Tailored processing methods and rigorously adjusted processing and material parameters guarantee optimal and controlled absorption of Activa™ implants. The complete absorption of the Activa™ implants lasts approximately 2 years

The implants absorb by hydrolysis forming lactic acid and glycolic acid as intermediate products, which are finally metabolized into carbon dioxide and water by human cells, which are then exhaled and excreted. 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 metabolic chemistry of mammalian cells. 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 and also the absorbtion products 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. 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. The manufacturing method of bioabsorbable implants has a remarkable effect on the strength, toughness and the hydrolytic absorption of the material. The advanced manufacturing technology employed to create Activa™ implants delivers high strength, toughness and predictable, controlled strength to the absorption properties. Bioretec implants are made of PLGA. They maintain their mechanical strength at least up to 8 weeks and absorb within approximately 2 years. On the other hand,  absorption crystalline remnants of weak PLLA have been found in tissue 4 to 7 years after implantation.

ID: WP40
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Comparison between ActivaScrew™ Interference TCP and Milagro® Advance Interference Screw: Fixation Strength In-vitro

Bioretec Ltd.

In this in-vitro study, the fixation strength of the ActivaScrew™ Interference TCP was compared to the Milagro® Advance Interference Screw. In the study pull-out test was performed initially (time zero) and during in-vitro up to 26 weeks. All pull-out tests were carried out in the 37 °C water bath. The initial fixation strength of the 7 mm ActivaScrew™ Interference TCP is about 12% higher than the fixation strength of the 7 mm Milagro® Advance Interference Screw and it stays higher during the in-vitro conditions being about 15% higher after 12 weeks.The first 12 weeks of the interference fixation are the most critical from the safety and effectiveness point of view, therefore the screws were compared during the first 12 weeks. The initial fixation strength of the 11 mm ActivaScrew™ Interference TCP is about 50 % higher than the fixation strength of the 11mm Milagro® Advance Interference Screw. The strength stays higher during the in-vitro conditions being about 14 % higher after 12 weeks. Fixation strength of the 11 mm ActivaScrew™ Interference TCP stays on very high level till weeks 20 in-vitro and starts to decrease slowly only after that time point.

Bioretec’s self-reinforcing technology also generates Self-Locking™ property to theActivaScrew™ Interference TCP, which causes screw diameter to increase about 2%during the first 12 weeks in-vitro. The Self-Locking™ feature of the ActivaScrews™ was originally developed to improve ActivaScrews™ fixation strengths and explains the superior performance of the ActivaScrew™ Interference TCP in this study as well. The ActivaScrew™ Interference TCP is available also in sizes below 7 mm, all the way down to the Ø4 mm, which is the world’s smallest strong biocomposite interference screw available.

ID: WP39
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Articular proximal first metatarsal bone fracture of a 14-year old patient fixed with one ActivaScrew™ LAG bioabsorbable screw.

Pierre Lascombes, Professor, M.D., Ph.D.

A 14 years old boy violently twisted his left foot, as he was doing gymnastics. The pain was intense and immediate weight-bearing was impossible. X-ray and CT revealed a displaced fracture of the proximal first metatarsal bone, with an oblique fracture toward the joint was. The patient was operated on day one through a skin incision centered medially on the cuneo-metatarsal joint. The plantar aspect of the proximal first metatarsal bone was approached as well as the fracture. As the control of the fracture was difficult by the direct view and also impossible with a classic 2D C-arm, we used our 3D C-arm. The images showed a perfect reduction of the fracture and allowed us to put a screw strictly perpendicular to the oblique fracture line. ActivaScrew™ LAG 3.5 was inserted to fix the fracture and absence of weight-bearing was six weeks postoperatively. X-rays at three months follow-ups showed an excellent bone union and a proper alignment. The boy was allowed to return to any sports activities like before.

ID: WP42
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Olecranon articular fracture of a 5-year-old patient, fixation with two ActivaScrew™ LAG screws.

Pierre Lascombes, Professor, M.D., Ph.D.

A roller-skating injury without any protection pads, a direct trauma to the left elbow of a 5-year-old boy. The pain was intense and immediate swelling of the elbow was visible.  X-rays demonstrated a rare type of fracture of the olecranon. A longitudinal line through the joint separated the olecranon in two pieces and ended into the coronoid process. A CT scan was required to understand better the type of the fracture, to confirm the subluxation of the radial head, and to measure the gap of the fracture. After three tries, attempts to reduce the varusdeformity of the ulna and to fix it with a K-wire were considered as not successful enough. So, an open approach and internal fixation were decided. The fixation was done with two partially threaded 3.5 mm ActivaScrew™ LAG bioabsorbable screws.

An immediate immobilization was done with a splint, replaced three days later with aresin above the elbow cast for 4 weeks. No physiotherapy was required, and the boy was allowed to move freely his upper limb. Six weeks later, the range of motion of the left elbow wascomparable with the right one. X-rays at 3 months follow-up showed an excellent boneunion and a good alignment, and boy had already returned to all sports activities likebefore. At 9 months follow-up, the clinical result was excellent with a normal function. The X-rays showed the complete bone-union and the position of both screws with holessurrounded by a bony ossification. The healing went as anticipated, very well. The fractured bone could continue growing normally without any implant removal operations.

ID: WP43
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Tillaux´ tubercle fracture of a 14-year old girl with one ActivaScrew™ Cannulated LAG

Pierre Lascombes, Professor, M.D., Ph.D.

 

A 14 years old girl with a twist of her right ankle following a gymnastic fall. X-rays demonstrated an articular fracture of the right distal tibia: the anterolateral tubercle (Tillaux’) is detached and displaced, as seen on AP and lateral X-rays. On the CT scan, the fragment is displaced of more than 2mm and requires a perfect reduction and internal fixation. In addition, a second fracture located on the posterolateral tibia. Through a percutaneous anterolateral approach, the dissection of tendons allowed to reach the fractured anterior fragment. K-wire was inserted through the reduced fragment till the distal metaphysis of the tibia. Due to the age of the patient (end of growth), it was considered possible to cross the physis which was almost mature. The fixation was done wiht partially threaded ActivaScrew™ Cannulated LAG. Postoperatively an immediate immobilization was done with a splint, replaced three days later with a resin below the knee cast. Six weeks later, the range of motion of the right ankle was comparable with the left one. X-rays at 3 months follow-up showed an excellent bone union and the girl was allowed to return to all sports activities like before.

ID: WP44
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