Traditional vs. 3D printed AFOs: what do patients say?

By
December 22, 2021

As 3D printing is becoming more common, we feel the need to stop and reflect on what this means for our practice, daily work, but also the patients we are working with. 

The field of ankle-foot orthoses (AFOs) is particularly interesting, leading many to predict lighter, stronger, and safer products with endless customisation possibilities. While that sounds exciting, we are also concerned about what technology brings to us right now. At the end of the day, orthopaedic technicians still have their regular duties, practice, planning, administration, and, of course, the patients they serve. Thus, we want to know how 3D technology fits into that, instead of being a distant promise.

We wrote about this in the previous article, where we compared the traditional manual and 3D printed process of making AFOs. Though it still may take up to 24 hours to 3D print orthosis, the process is significantly faster, easier, and more reliable for the technicians. Because there are fewer tools to deal with, and the printing itself is autonomous, technicians have more time to do the meaningful work and focus on the patients.

But one question remains: what do patients say? Are they satisfied with the 3D-printed AFOs? 

Time to tackle this.

Traditional AFO is a long process for patients 

The traditional or manual process of making AFOs is complex and time-consuming. It calls for different materials and a variety of measurement and shaping tools. Multiple steps of making the orthosis require precision and expertise, from taking measures, molding, to polishing and adjusting. That means that the orthotist spends less time with the patient, potentially disconnecting from their needs and individual cases. 

As any technician will confirm, no matter how experienced and skilled they may be, errors happen. For example, the manual and paper-based measuring can be lost, or interpreted differently, influencing the rest of the making process. Some steps, like correcting the positive mold, may further decrease the accuracy or even break the orthosis. All of that means that the chances of the orthosis fitting the first time are low.

That process reflects on the patients and their time as well. Though they might understand the long-term benefits of wearing an AFO, the process of getting the correct one can be frustrating and discouraging. This is only reinforced as their condition or lifestyle changes and a new fitting is needed. It is even harder for the younger patients who are still growing. As their body shape changes, their orthosis-related needs change along. 

Traditional process of making AFOs
Traditional process of making AFOs is long for patients too

Low satisfaction and patient compliance

The traditional AFOs are single-serving, and generally speaking, customisations are hard. When the patient needs an emergent replacement or adjustment for any reason, the orthopaedic technician must return to the molding and fitting stages. Sometimes, the technician will have to start the whole process from the top.

Moreover, the AFOs can be heavy, impractical and may limit movements in an unwanted way. Studies like the one by Vinci and Gargiulo, or a newer one by Başaran, Sibel, et al. show low satisfaction and patient compliance. All due to the physical limitations of AFOs. Besides, skin irritations occur quite often. Modern orthoses are designed and made to fit tightly around a limb, which may cause redness, blisters, or rubbing. Much of that can be prevented with proper care for and wearing of AFO. Yet, the additional pressure on the skin and redness are inevitable parts of the orthosis-wearing experience.

Can 3D-printed orthosis solve these issues?

Some studies tried to answer this by comparing the experience of wearing a traditional AFO with that of wearing a 3D-printed version.

Here is what they say.

Wearing traditional vs. 3D printed AFOs

We will start with the 2017 study done by Cha, Yong Ho, et al., who have done multiple gait tests and surveys. Comparing the two types of orthosis, they conclude that traditional and 3D printed AFOs have similar functionality. However, they also report overall higher satisfaction rates among patients who wore a 3D printed AFO when it comes to weight and ease of use. 

This study included a QUEST (Quebec User Evaluation of Satisfaction with Assistive Technology). Patients were asked to assign a score from 1 (very unsatisfactory) to 5 (extremely satisfactory) to the AFO they were wearing. They had to rate them on the dimension, weight, adjustment ability, safety, durability, ease of use, comfort, and effectiveness. The 3D-printed AFOs scored a 5 on weight compared to the conventional orthoses that scored only 3. 

Wojciechowski’s study from 2020 focused on children using 3D printed orthosis. For young patients, the traditional AFOs are cumbersome and associated with low acceptability, discomfort, and difficult function. The study concluded that 3D printed orthosis can easily replicate the design and gait of a well-functioning orthosis. But more importantly, it can increase the acceptability and satisfaction of those who wear it.

Finally, in this extensive review study, the authors also point to the great satisfaction patients report after wearing 3D printed orthoses. Specifically for lower limb orthosis, they quote a better pressure distribution and comfort. 

Another considerable advantage of the 3D printed orthosis is the possibility to customise it to great extent and make it very personal to the patient. The technology allows different materials, making a waterproof or less sturdy AFO possible. 3D-printed AFO can also come in a wide range of colours and patterns. This may not affect the functionality of the AFO but personalised orthosis can make up for a far more enjoyable experience, especially in young patients. 

The customisation goes beyond the way orthosis looks. The digital storage of the patient’s data and measurements allows the orthopaedic technician to quickly find and modify the information needed to make a new orthosis. This alone reduces the time the patient needs to wait.

 Let us explore this by zooming in one area only: foot drop orthosis.

3D printed orthosis
3D printed AFOs are significantly lighter compared to traditional ones

Treating Foot Drop with AFOs

We are focusing on foot drop because it is a very common condition across age groups. 

Foot drop is an inability to lift the forefoot due to the weakness of the dorsiflexors. Causes can vary but foot drop is often a consequence of squashing (compressing) of the nerve that controls the muscle that lifts the foot. The fibular and peroneal nerves lay superficially underneath the skin near the knee and are therefore prone to pressure palsies resulting in foot drop. Palsy of the peroneal or fibular nerve can be a devastating injury and is the most common mononeuropathy of the lower extremity.

Though there are no good reports on the overall incidence (frequency) of foot drop, studying associated conditions like the peroneal nerve palsy could help. Carolus, Anne Elisabeth, et al. did exactly that and concluded that nerve palsy has a high prevalence of 19 per 100 000 people. Considering that the most common presentation of it is acute, complete, or partial foot drop, we can conclude that foot drop is anything but rare.

Orthoses are not the only way to treat foot drop but they are necessary in most cases. As this article puts it, AFOs are helpful devices that enable people to walk better and more safely, primarily in cases of severe foot drop. Just as we discussed above, the typical way of making AFOs is usually difficult for children and patients with varying conditions due to the time it takes and the lack of customisation options.

3D printing allows exactly that. Producing accurate and customised orthosis makes the patients happier. As a result, they are more likely to wear them regularly and properly. That is crucial in treating conditions like foot drop.

Additionally, such orthosis is far easier to take care of and they are usually more breathable and lighter. It also means that it causes less skin irritation and sores. 

In other words, 3D printed AFOs are more practical and attractive for patients with foot drop. These AFOs could potentially help many more patients who are hesitant or resisting heavy and impractical orthosis. Since the experience of wearing a 3D-printed one proves to be a far more enjoyable experience, patient compliance might increase. 

To sum up, here are the key advantages of 3D printed orthosis for patients.

Advantages of 3D printed AFOs for patients

Lightweight: compared to the manually-made ones, the 3D printed AFOs are significantly lighter and thus less restrictive

Comfort: due to the lightness but also more accurate making process, patients report a greater comfort when wearing a 3D printed AFO. Skin irritations, redness, and blisters occur less than in traditional AFO.

Customisation and personalisation: it is easy to adjust the orthosis to the patient’s needs but also tastes and preferences (colours, patterns, materials, and so on).

Patient compliance: the wearing experience is more enjoyable and the patients are more likely to agree to wear the orthosis

Better hygiene: being breathable and light, 3D printed AFOs are easy to clean and take care of

These are some of the key reasons why we developed the newest Spentys software feature for designing and making AFOs. We invested our time in coming up with a program that helps you make orthosis your patients will enjoy and trust. 

Interested in learning more? 

Book a call with one of our specialists here

References

Vinci P, Gargiulo P. Poor compliance with ankle-foot-orthoses in Charcot-Marie-Tooth disease. European journal of physical and rehabilitation medicine. 2008;44(1):27-31. https://www.semanticscholar.org/paper/Poor-compliance-with-ankle-foot-orthoses-in-Vinci-Gargiulo/8db88a91bf622a909b7e1af6a71a6df776907002

Başaran S. Actual use and satisfaction of lower extremity orthoses in neurological disorders. Türkiye Fiziksel Tıp ve Rehabilitasyon Dergisi. 2016;62(2):143-147. doi:10.5606/tftrd.2016.96236

Cha YH, Lee KH, Ryu HJ, et al. Ankle-Foot Orthosis Made by 3D Printing Technique and Automated Design Software. Applied Bionics and Biomechanics. 2017;2017:1-6. doi:10.1155/2017/9610468

Wojciechowski E. Personalised orthotic therapy using 3D printing in children with Charcot-Marie-Tooth disease. seslibraryusydeduau. Published online 2020. https://ses.library.usyd.edu.au/handle/2123/23718

Choo YJ, Boudier-RevéretM, Chang MC. 3D printing technology applied to orthosis manufacturing: narrative review. Annals of Palliative Medicine. 2020;9(6):4262-4270. doi:10.21037/apm-20-1185

Carolus AE, Becker M, Cuny J, Smektala R, Schmieder K, Brenke C. The interdisciplinary management of foot drop. Deutsches Aerzteblatt Online. 2019;116(20). doi:10.3238/arztebl.2019.0347

Stewart JD. Foot drop: where, why and what to do? Practical Neurology. 2008;8(3):158-169. doi:10.1136/jnnp.2008.149393

Walbran M, Turner K, McDaid AJ. Customized 3D printed ankle-foot orthosis with adaptable carbon fibre composite spring joint. Meng W, ed. Cogent Engineering. 2016;3(1):1227022. doi:10.1080/23311916.2016.1227022

Stay up to date on new content, Spentys news and more