Ankle joint orthosis of the pelvic limb for the dog

Design Pro Technology Sp. z o.o. offers products and services in the field of orthopaedic supplies for humans and animals. Its main field of activity is prosthetics and limb orthotics. An everyday part of the company's life is the extremely precise fitting of products to the patient's anatomy, hence the need to use 3D printing technology. Since 2020, the company has been using two OMNI3D Factory 2.0 printers. The devices are used for both prototyping and making end products such as cosmetic coverings, active orthoses and dynamic prostheses.

Challenge

The company recognized the growing pet healthcare market and decided to start producing prostheses and orthoses for pets using the latest technology available – including 3D printing. It uses prostheses to replace a missing limb or part of a limb and restore its function. Orthoses, on the other hand, are used to improve the function of a limb by stabilizing it and/or immobilizing isolated movements in a joint. Orthoses also protect the joints from possible injury or overload. Orthoses or prostheses are increasingly becoming an alternative to expensive and dangerous, invasive surgery. The use of a prosthesis or orthosis at the right stage of treatment, under the guidance of a specialist, allows the pet to return to normal locomotion with everyday activities, which undoubtedly brings a lot of joy to dogs, cats, their owners and also to the Design Pro Technology team.

Application

The orthosis on display was created in CAD software – SolidWorks, based on a 3D scan of the hind limb negative. The patient – a female Lisia – came to Design Pro Technology straight from the vet, with a drooping hind foot of her right paw. On the basis of research, an orthosis was created that stiffens the ankle joint in its normal position so that the claws, toes and paw do not rub against the ground when walking, thus preventing wounds. Because the orthosis is dynamic, the ankle joint can have a free-range of movement in the sagittal plane during the gait cycle, while providing rigid support for the paw.

The orthosis was printed on a 3D printer. It consists of rigid, tight-fitting scales made of resilient material and flexible connectors that allow limited, isolated flexion and extension movement in one axis. The orthosis attaches with Velcro straps and is finished inside with seamless soft foam. The four 3D printed components can be divided into two processes due to the material used. 

Figure 1: Finished printout of cosmetic coverage divided into two processes

Table 1. Printing parameters of the canine thoracic limb prosthesis

Solution

Using 3D printing, we effectively reduce the time it takes to produce prostheses, while increasing the precision of their manufacture – the orthosis shell accurately reproduces the anatomy of the limb. There is also no need to process the part after printing, as the surface obtained during the 3D printing process meets customer expectations. With small batch production, thanks to the use of 3D printing, we are able to meet market demands for product personalisation and speed of production – which is particularly important in emergency cases.

Effect

The transition from the traditional vacuum method to 3D printing technology has revolutionized the production of animal prostheses at Our Company. The introduction of the incremental manufacturing method has allowed us to reduce the number of manpower required to work on plaster measures and the creation of stump positives. In addition, we have minimized the chance of human error resulting from the machining and manual fitting of the scales to the anatomical structures by the orthopaedic technician. This process is now done in a CAD computer environment. As a result, production costs have fallen, as savings have been made on materials, tools, employees, and company square footage. The main plus point is the possibilities of individual design and rapid prototyping, which are not possible with other production technologies.