The Direct Socket: The Science Behind This Innovative New Technology, How It Compares To Traditional Prosthetic Casting, And If It Is Right For You

Infinite Technologies Orthotics and Prosthetics has geographically partnered with Össur, the inventors of the Direct Socket, as the premier facility in the Capital Region to offer this exciting new prosthetic socket technology. With the Direct Socket system, a definitive prosthetic socket can be made right on an amputee’s leg in only a few hours instead of over several weeks. This blog will outline the benefits of direct socket vs traditional socket fabrication methods, science behind the direct socket, who is a good candidate for the direct socket, and how patients are doing in the direct socket.

Benefits of direct socket vs traditional socket fabrication methods

The traditional method of making prosthetic sockets typically consists of several steps spanning over an average of 16 weeks from initial evaluation to final delivery1. First, a cast or scan is taken of an amputee’s leg. Then, plaster is poured into a mold and modifications to the mold are made by a prosthetist. After the mold is ready, a plastic “check socket” is made then worn by the patient for several weeks. Issues with the fit of the check socket are then reviewed, and then a new check socket is made for and worn by an amputee for several more weeks. After an average of 2-3 check sockets, a definitive socket made of carbon fiber and resin is laminated on a mold of the inside of the patient’s most recent check socket. With the Direct Socket system, a definitive socket is laminated directly on a patient’s leg in only 4 hours, with no molds, no check sockets, and less visits into the office.

There are several advantages with being able to craft a definitive socket in one appointment. These include:

  • Less trips and time spent in the office – Traditional socket fabrication takes an average of about 4 one-hour visits over a 16-week time span, with additional follow up appointments necessary1. The direct socket requires on average 2 appointments (measure for liners and then fabrication), with an average of only 1/3 of patients needing to follow up following delivery1.
  • Ability to fabricate in clinical or rehab settings – Due to the direct socket being made directly on a patient’s limb in one appointment, a prosthetist is more portable than in the past.
  • Optimized suspension and limb control – Traditional socket fabrication techniques require a clinician to perform modifications to a mold of an amputee’s leg. This leaves room for possible error. The direct socket is formed on a patient’s leg in real time, resulting in better socket fit, and reducing the chances of a socket not fitting correctly.
  • Overall cost of rehabilitation and time from amputation to definitive leg is drastically reduced – It is estimated that a prosthesis accounts for only about 10% of total rehabilitation costs following amputation1. The bulk of rehab expenses come from the amount of time spent in rehabilitation. Reducing the amount of time between amputation and leg delivery can reduce rehabilitation costs by upwards of 25%, and research shows that shorter time to prosthetic fitting led to improved functional outcomes 6 months following amputation1.

Benefits of direct socket vs traditional socket fabrication methods

The technology for the direct socket originated in Scandinavia in the 1990s, but has only recently undergone rigorous testing and approval in the United States1. The direct socket laminates a final socket directly on a patient’s leg instead of on a mold.


First, a special casting liner is worn by the amputee, as well as a silicone protective sheath.



The materials for the socket are then applied to the limb, and a resin is added to harden the socket.

After the socket has hardened, a prosthetist draws on trimlines, and you get to walk out with a new definitive socket the same day.

Who is a good candidate for the direct socket?

  • Transtibial and transfemoral amputees The direct socket is available for transtibial, or below knee, and transfemoral, or above knee, amputees. If you have a bulbous end to your residual limb, or are a knee disarticulation patient, talk to your prosthetist and see if a direct socket could be right for you.
  • All K Levels Research has proven that amputees of all K levels, spanning from K1-K4 can benefit from the direct socket1,2.
  • New and experienced prosthesis users – Research demonstrates the direct socket benefits new1 and experienced prosthesis users2 alike, with both groups significantly improving their Timed-Up-and-Go (TUG) Test and AMPPRO (the test which determines K level) scores when using a direct socket interface instead of a traditionally made socket, regardless of suspension style2. In the same study, even amputees who did not necessarily need a new socket due to improper fit or function scored better on their clinical outcome tests and overall comfort scores when wearing their direct socket at their 6 month follow up appointments2.

Who is a good candidate for the direct socket?


Research shows promising data on how patients are doing in the direct socket compared to traditional sockets.

Recent research demonstrates that amputees reported the direct socket significantly improved their stability, suspension, comfort, and they preferred the socket appearance compared to a socket made with traditional methods2. Not only are patients saying their direct sockets fit and feel better, but they are performing better on outcome measure tests in the direct socket. Direct socket users improved their Timed-Up-and-Go (TUG) Test by an average of 2-3 seconds compared to their baseline scores2. Multiple studies have shown that AMPRO scores, the test which determines K Level, have improved by an average of 2 points when using the direct socket system over a traditionally-made socket1-3.


If you have any questions about the direct socket system, please feel free to reach out to Infinite Technologies Orthotics and Prosthetics via email Contactus@infinitetech.org. Talk with your prosthetist and see if the direct socket is a good option for you, or call (703) 807-5899 to schedule your free consultation today!

References:


  1. Marable W.R, et al. Transfemoral socket fabrication method using direct casting: outcomes regarding patient satisfaction with device and services. Canadian Prosthetics and Orthotics Journal. 2020; Volume 3, Issue 2, No. 6. https://doi.org/10.33137/cpoj.v3i2.34672
  2. Walker J, et al. Clinical outcome of transfemoral direct socket interface (part 2). Canadian Prosthetics and Orthotics Journal. 2021; Volume 4, Issue 1, No.6. https://doi.org/10.33137/cpoj.36065
  3. Ennion, L et al. The use of a direct manufacturing prosthetic socket system in a rural community in South Africa: A pilot study and lessons for future research. Prosthetics and Orthotics International. 2017; Volume 4, Issue 5, pp 455-462. Https://doi.org/10.1177/03093646166839982
07 Jun, 2022
Infinite Technologies Orthotics and Prosthetics has geographically partnered with Össur, the inventors of the Direct Socket, as the premier facility in the Capital Region to offer this exciting new prosthetic socket technology.
SDO Vs SPIO
21 Feb, 2022
The sensory dynamic orthotics (SDO) are a custom made to measure product, designed to provide compression to increase sensory and proprioceptive feedback as well as support to the musculoskeletal system [1]. The compressive garment comes in a wide range of designs and style options, from a glove to a full body suit.
31 Oct, 2021
Osseointegration is a surgery that inserts a metal implant into a bone. Osseointegration was first introduced in the 1950s and today is commonplace in dental implants, hip and knee replacements, and newly with prosthetic limbs.
12 Nov, 2020
Signs of damage such as cracks, warping and compressed padding are the first indicators there may be an issue. Check the arch of the orthotic. When the arch is compressed it should retain a sturdy shape. Arches that collapse too easily do not provide the support you need.
03 Oct, 2020
No matter what your activity level is, it is important to stretch your ankles and calves every single day. Whether you are an active person or someone who is required to be seated majority of the day, stretching consistently will allow an increase in flexibility, decrease pain, and reduce your risk of injury such as Achilles tendinitis.
13 Feb, 2020
Adolescent Idiopathic Scoliosis is an abnormal curvature of the spine that appears in late childhood and into a patient’s teenage years. It is diagnosed through physical exam and x-rays. The spine develops a curvature, usually presenting as an S or C shape and can also have slightly twisted or rotated presentation.
13 Jan, 2020
The world of Orthotics/Prosthetics and the world of Physical Therapy. Two worlds that at times have collided, but when collaborative they can have a profound impact on the outcome of a patient’s care.
By Scott 13 Jul, 2019
Have you been in an accident and injured your cervical spine? Have you had corrective surgery in cervical or upper thoracic spine? Here is some information that will help you during your healing process and how to properly wear your doctor prescribed cervical collar or cervical-thoracic orthosis (CTO).
By Scott 04 Jul, 2019
One of the important features of a prosthesis for lower limb amputees is the prosthetic foot. There are many different models of feet by several companies, such as Otto Bock, Ossur, Endolite, Freedom Innovation and College Park. As the prosthetist knows, choosing the right prosthetic foot is very important for the patient. The foot can help the patient perform specific tasks, such as running, or just help with every day walking. As the field of Prosthetics has evolved, so has the feet.
By Scott 05 Jun, 2019
A detailed written order is a document used to authorize what was ordered by a patient’s treating/prescribing physician. Detailed written orders must include all billable items, accessories or supplies related to the base item that is ordered. Some DME suppliers use prepopulated forms for their detailed written orders. If the supplier provides their own form, on these forms, the final document that is signed by the physician must clearly state what item(s) is being ordered for the patient. This may be done in two ways: • The DME supplier may indicate the items that are being provided before sending the form to the physician. The physician can then review the form and accept the items marked by the supplier or, make any necessary changes. The physician must then initial and date the revised entries. • The DME supplier may send the form to the physician without any items selected and ask the physician to indicate which items are being ordered. The physician must make their choice very clear. In each case, the physician must sign and date the form before returning it to the supplier. A DWO is required prior to billing. All DWO’s must include: Patient/Beneficiary’s name, date of the order, detailed description of all items, prescribing physician’s signature and date. Friendly Reminders • Medicare requires an order for every item of durable medical equipment. • Signature and date stamps are not allowed. Signatures must comply with the CMS signature requirements outlined in PIM 3.3.2.4. • If a DME supplier does not have a faxed, photocopied, electronic or pen and ink detailed written order signed and dated by the prescribing physician in their records before they submit a claim to Medicare, the claim will be denied. • If the claim is for an item for which an order is required by statute (e.g., therapeutic shoes for diabetics), the claim will be denied as not meeting the benefit category and is therefore not appealable by the supplier (see CMS Manual System, Pub. 100-04, Medicare Claims Processing Manual, Chapter 29). • For all other items, if the DME supplier does not have an order that has been both signed and dated by the treating physician before billing, the item will be denied as not reasonable and necessary, except for items requiring a written order prior to delivery. If an order is taken verbally and sent to the physician for a signature and date, there are two documents: the verbal order and the written order with the physician’s signature and date. If a beneficiary comes in with a prescription containing all the elements of a detailed written order, then one document is on file. It is important to remember that if an item is dispensed based on a verbal order and a written order is provided afterwards, both orders must be retained. It is not adequate to only have a written order after dispensing an item. There must be documentation to show the verbal order was received prior to dispensing the item. Resources: https://med.noridianmedicare.com/web/jddme/topics/documentation/detailed-written-orders https://cgsmedicare.com/jc/pubs/news/2010/0410/cope12010.html
More Posts
Share by: