Description of manufacturing process
Referrals from licensed physicians and/or EOPYY are essentially official documents that serve as work orders and enable the Orthopedic Center to plan and perform the necessary work, i.e. the relevant preparation in order to determine the requirements of the orthopedic brace to be manufactured.
The instructions and diagnosis of the attending physician are taken into account. In case of ambiguities or if further clarification is required, the Production Manager shall ensure that they are resolved in the most appropriate manner (by telephone, in person, by exchanging letters, etc.) directly with the attending physician. Once the diagnosis requirements have been clarified, the digital scanning system operator is notified so that the process of designing the required body cast can begin.
The Secretariat checks whether all the information that must be included in the referral documents (referrals) is present and, if not, ensures that it is sent immediately by the attending physician. Specifically for EOPYY referrals, the actions provided for by the National Organization and the relevant Agreement are followed, which include entering the information into the coded electronic application/ database that is in operation, while the original referral forms are forwarded to the accounting department for dispatch to the National Organization (sent on a monthly basis).
The procedure followed for taking measurements, designing, and constructing the necessary body mold is described below.
Taking measures
The measures taken include scanning the patient’s body using a white light digitizer and associated software, as well as measurements with a tape measure and caliper.
The patient stands on a rotating base wearing a tight-fitting T-shirt. When digitization begins, the base rotates completely and the patient’s body is scanned circumferentially, while the scan is displayed in real time on the computer screen. Once digitization is complete, a three-dimensional model of the patient’s body appears on the computer screen. The file is saved for subsequent processing.
Additional measurements are taken with a tape measure and caliper, and the Measurement Form EN 8.2-01.1 or EN 8. 2-01.2 form is completed with the patient’s details, measurements, condition, information obtained from the patient’s X-ray, any comments added by the attending physician, and any comments the technician may have.
Design
The same software used to digitize the patient’s body is also used to prepare the basic form of the patient model, using tools provided by the software itself. This preliminary work includes cutting out unnecessary points, smoothing the surface, and removing noise. These procedures are performed so that further work can be done on the digital model in the best possible form.
The digital file of the patient’s body (digital cast) is then processed using Rodin4D’s CAD/CAM design software. The necessary corrections and adjustments are made according to the requirements of the doctor and technician at the time and based on the specifics of each case. The basic tasks performed on the patient’s digital model are as follows:
- Balancing the model in relation to its central axis.
- Modifying the size of the radius or diameter of the model where necessary.
- Elongating, if necessary, the entire model or a zone between two planes.
- Delineation of an area and filling or indenting it.
- Smoothing of these areas.
- Comparison of the dimensions of the model shown by the program with those taken with a tape measure and caliper, and processing them if necessary.
The processed digital model is then stored and transferred to the CNC machine’s computer via a memory stick for cutting.
Cast cutting
To cut the mold, the appropriate size of polyurethane block is selected, placed in the cutting machine, and the computer is instructed to cut the mold.
The mold is then checked by technicians and, if necessary, corrections are made manually. After the mold has been checked, the construction of the retainer begins.
The following points should be noted:
- The company keeps a digital file of the patient’s scan.
- Patient molds are stored for possible future use if they are deemed suitable.
A patient’s mold can be reused to make a brace for another patient if they have the same dimensions, with a permissible deviation of + 2 to 3 cm, and if the type of scoliosis or kyphosis is the same. Manual corrections can also be made to the molds to achieve the appropriate dimensions, such as sanding with a rasp to reduce dimensions or adding foam plastic (plastazot) to increase dimensions.
Construction of initial guardian form
Once the patient’s body cast is ready, the construction of the brace begins. (It is possible to use a ready-made cast of the patient if it fits).
The overall dimensions of the cast are calculated and, after cutting a corresponding sheet of plastic, it is placed in a special oven to heat and soften. The plastic sheet is removed from the oven when it reaches a temperature of approximately 187-192 degrees Celsius, depending on the thickness of the plastic used.
It is then molded with heat-insulating gloves around the patient’s cast, sticking the two ends to the back surface (or the front, depending on the case), where it will later be cut to be removed after it has cooled and stabilized. At this point, we have the retainer in its initial form.
Rehearsal
When the patient comes in for the fitting, the molded and cooled plastic has the ability to stretch so that it can be opened relatively easily from the back surface where it is cut and placed around the patient.
It is applied well to the pelvis and temporarily tied with straps.
The points to be cut at the armpits and above the pubic symphysis are marked and then, with continuous testing, it is cut at the groin, just enough to allow full flexion of the thighs and comfortable seating for the patient.
It is designed and cut at the front so as to leave the chest free and at the back so as to cover the corners of the shoulder blades (the cut is made using a saw).
When the testing process is complete and the brace fits the patient correctly without causing pain or discomfort when sitting or walking, the outline of the brace is smoothed and evened out so that there are no protrusions or rough edges from the cut.
The entire structure is then reinforced with aluminum metal supports in areas subject to strong forces, such as the vertical opening on the back surface and one of the two sides of the front chest wall, while the other side is reinforced with a piece of the same material as the frame itself.
The counterpressure pads (metal pieces made of duralumin, approximately 7 cm high and 15-18 cm wide, depending on the case) are placed in the appropriate locations.
Small holes are made across the entire surface of the brace to allow the body to breathe.
Pieces of foam plastic, plastazot, are attached to the pressure points to exert greater pressure. The same material is also placed in the armpits so that the plastic does not cause discomfort, and on the inner surface of the metal reverse pressure points.
The unique serial identification number (S/N: 6-digit sequential number) is engraved on the brace. . In cases where the same patient returns after a certain period of time for the manufacture of a new brace, the initial serial identification number is retained with the addition of the characteristic – 2, -3, etc. This ensures that each retainer is uniquely identified, unambiguously matched to the patient, and fully traceable.
For front-closing braces (Cheneau), the manufacturing process is the same, with the difference that there are no metal supports and pressure plates at the back, while there are two metal supports at the front.
The metal supports and pressure plates are cut to the appropriate dimensions from rods and aluminum sheets, respectively, filed down so as not to cause injury, and riveted onto the brace.
The straps are sewn on site each time to the required dimensions and are also fastened with rivets.
All of the above work is documented in the Orthopedic Product Production and Control Order Form EN 8.5-01.1. The form allows for the complete interconnection of raw materials, operators, and, more generally, the work performed with the specific orthopedic device, so that full traceability is possible.
Delivery of final product
All of the above tasks are performed by the production laboratory technicians and supervised by the production manager. Before the final delivery of the product, the patient wears the brace for a final check by the production and quality control manager. It is checked that the brace does not cause discomfort or pain to the patient and fits correctly on the patient’s body. Instructions for using the brace are given verbally and in writing, and a demonstration of how to use it is provided.