Local design and manufacturing of patient-specific implant using Anatomage Medical Design Studio software: proof of concept - Botswana's 1st case report.

BACKGROUND: Botswana, like most sub-Sahara African nations, uses conventional orthopaedic implants that are sourced from major manufactures in the West. The implants are mass-produced and designed with universal configurations to fit an average patient. During surgery, surgeons thus sometimes bend the implants to match the individual bone anatomy, especially for paediatric patients and those with unique deformities, thus risking implant failure. The purpose of this project was to show the feasibility of developing safe and effective patient-specific orthopaedic implants in a low-resourced market. METHODS: CT Scan slice files of a paediatric patient with Ollier's disease were used to reconstruct the lower limb anatomy. The resultant files were 3D printed into prototypes that showed severe right knee valgus deformity. The surgeon used the prototype to plan for corrective femoral osteotomy and the required implant. The implant design and planned surgery were subsequently simulated on the Medical Design Studio software for proper fitting before final implant printing. Surgery was then performed, followed by 12 weeks of physiotherapy. RESULTS: Post-surgical x-rays demonstrated good implant positioning and knee joint alignment. At 18 months of post-surgical follow-up, the child was pain-free, could perform full squats, and ambulation was near-normal, without the use of an assistive device. CONCLUSIONS: It is feasible to develop effective, patient-specific implants for selected orthopaedic cases in a low-resourced country. This work could improve surgical and rehabilitation outcomes for selected paediatric patients and those with severe bone deformities.

Dual polymer networks: a new strategy in expanding the repertoire of hydrogels for biomedical applications.

Inspired by the double network hydrogel systems we report the formulation of dual networks, which expands the repertoire of this class of materials for potential biomedical applications. The tough dual network hydrogels were designed through sequential interpenetrating polymer formation, applying green chemistry and low-cost methods, devoid of any initiator-activator complexes that may pose risks in biomedical applications. The dual networks were synthesized in two steps, firstly the water soluble poly(vinyl alcohol) was subjected to cryogelation that formed the first network, which was then expanded by intrusion of a dilute solution of sodium alginate and complexed with a solution of calcium chloride under ambient conditions and further freeze-thawed. These hydrogels are flexible, ductile and porous with the ability to absorb and retain fluids as well as possess the versatility to easily incorporate biological molecules/drugs/antibiotics to be applied in tissue matrices or drug delivery systems. The dual network hydrogels can be tailored to have varying mechanical properties, shapes, size, thickness and particularly can be made physically porous if required, to suit the users intended application.

Combinatorial design of calcium meta phosphate poly(vinyl alcohol) bone-like biocomposites.

The incidence of degenerative diseases and the ageing population have added to the growing demand for bone grafts. Although autologous bone continues to be the gold standard, limited yield and potential morbidity of the donor site pose considerable challenges. Currently, clinically used synthetic grafts based on calcium phosphates are mechanically brittle and not compliant hence composite scaffolds are expected to be provide viable solutions. In this study we report composites of calcium meta phosphate-poly (vinyl alcohol) with tunable mechanical properties, low swelling and excellent biocompatibility. The elastomeric nature of the composites resist brittle fracture and the scaffolds can be easily shaped to the bone defect by the surgeon. Testing on bone plug shaped specimens of the scaffolds, exhibited superior mechanical properties compared to currently commercially available bone plugs with additional advantages being the ability to increase porosity without compromising properties in compression and degree of swelling, which make these composites promising synthetic alternatives for bone grafts and bone tissue engineering.