Assessing Orthotic Quality

Start Page: 46

Case Study: When You Should Reevaluate Orthotic Accuracy

A 34-year-old patient came into my office complaining of a painful neuroma of the left forefoot. This condition was making it difficult to do her regular walking exercise. She noted that another doctor had previously taken X-rays, which were negative. The doctor had given local injections which only provided temporary relief. Although foot taping had given her significant relief, she said the orthotics she had were not successful in relieving her symptoms. She was scheduled for surgery and came to see if there were any other alternatives.

Since the patient noted the taping had given her relief, I decided to evaluate the orthotics for accuracy. First, we checked for strength and found the orthotics to be strong enough for her weight and pronatory forces. When we checked the contour, we noted a 5mm gap in the arch bilaterally, which allowed the patient’s midtarsal joint (oblique axis) to pronate in the sagittal plane to contact the plate. We decided to correct this.

Next, we checked the patient in the prone position and noted that she needed 6 degrees of valgus correction. The orthotics actually had 2 degrees of varus correction. We recasted the patient, followed our measurements and she experienced a similar reduction of symptoms as her previous taping had provided.

Remember, just because a patient says he or she has orthotics, make sure they are made correctly before proceeding to more invasive treatment. It helps to be as objective in your prescribing as possible.

The shape of the orthotic plate should match the shape of the plantar aspect of the foot with the STJ in neutral position and the MTJ(s) pronated and locked.
If the patient responds well to low Dye taping and not so well to the orthotics, check the makeup of the orthotic device.
Make sure the rearfoot post  is properly angled as you requested; is tapered so it doesn’t get malpositioned by the shoe; and has proper height so as to correct for limb length differences when necessary.
51
Author(s): 
By Arnold Ross, DPM

Numerous patients use orthotics and have improved foot function as a result of wearing them. Not only do they experience relief from previous pain and symptoms, but wearing orthotics also helps to prevent recurrence of foot, leg and other skeletal pains and conditions. Unfortunately, there are also numbers of patients who are either unable to tolerate their orthotics or are not getting symptomatic relief. We are often asked to evaluate many of these patients and assist them in getting better results from their orthotics.
People may hear about orthotics in different ways, whether it’s through their doctor, advertising, sports reports of famous orthotic users or word-of-mouth from friends. As the public becomes more aware of orthotic devices for their feet, it is our responsibility as podiatrists to be able to evaluate the quality and accuracy of their fabrication.
However, as we know, the field surrounding orthotics and their application can be highly subjective. In order to keep the evaluation as productive and helpful as possible, I’ve found that a system of criteria to check allows more objectivity and helps ensure more consistency and reproducibility in working with patients who have new or old orthotics.

Often patients come into our practice with a foot complaint that has strong implications of foot or leg biomechanical abnormality. After getting the history, examining the foot, performing gait analysis, etc., we may recommend foot orthotics. Often, the patient will announce, “I already have orthotics.”

Conveying The Importance Of Properly Made Orthotics
At this point, we owe it to the patient to properly evaluate that orthotic. If it is made incorrectly, we need to let the patient know and offer to remake it properly before he or she considers invasive treatment options. Patients may decide to go ahead with the next step in treatment, but at the very least, we can let patients know the status of the orthotic.
If the orthotic is made correctly, then we must evaluate their shoes, activities, etc., even when patients elect more invasive treatment, such as surgery. We should let the patient know how important it is for the orthotics to be made correctly and accurately in order to prevent acceleration of the problem and/or recurrence.

Does The Device Meet Orthotic Goals?
When evaluating orthotics for a specific patient, we are essentially checking multiple processes. We are checking to see if the original cast or image was done accurately. Did the lab do the correct work on the cast or image sent to it prior to fabrication? Was the final orthotic plate or shell or module made properly from that final positive cast?
Our basic premise in fabricating orthotics is trying to position the patient’s foot in or near subtalar neutral position with the midtarsal joints(s) fully pronated. This allows optimal shock absorption at contact phase by allowing subtalar joint pronation (with its associated internal tibial rotation and subsequent knee flexion), which is where the main shock is absorbed. Then in late heel contact and through midstance, the midtarsal joint is pronating and adapting to the terrain. After midstance, the pronation stops and resupination of the subtalar joint begins with external tibial rotation, which is caused by rotation of the axial skeleton and hips. Then there is reduced range of motion of the midtarsal joints, converting to a “rigid lever” that allows patients to push off from a stable support.
If any of the following three criterion for proper orthotic fabrication is violated or inaccurate, you will have compromised the “correction” of the patient’s walking. When evaluating a patient’s orthotic, be sure to evaluate for strength, contour and balance.

image description image description


Post new comment

  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.

More information about formatting options

Image CAPTCHA
Enter the characters shown in the image.