Case Studies: The F-Scan^® System

1. The Diabetic Foot

2. Identifying High-Risk Areas in the Neuropathic Foot before Orthotic Construction

3. The Challenge of Redistributing Pressure using an Orthotic Device in Patients with Peripheral Neuropathy

4. Utilizing Dynamic Analysis to Identify Multiple High-Risk Areas and Prevent Transfer Lesions in the Neuropathic Foot

5. Optimizing the Protective Function of Footwear during Post-Surgical Wound Healing using the F-Scan

This case study focuses on the evaluation of the biomechanical function of a patient with an insensate foot and plantar ulceration.

Today, 5.9% of the American population suffers from diabetes, and an estimated 5.4 million people have not yet been diagnosed. Since approximately 2 million Americans with diabetes suffer with foot ulcers, proper patient screening and examination are crucial in preventing further complications, including nerve damage or even amputation.

The F-Scan system by Tekscan enhances your ability to obtain information concerning the diabetic foot, as well as other pathologies associated with a neuropathic foot. In this case study, the F-Scan system qualitatively and quantitatively displays the effects of the orthotic device in relieving and redistributing pressures along the plantar surface. The F-Scan system provides both the practitioner and the patient with easy to interpret data that shows the dynamic weight transfer with and without the orthotic.

The pressure profile generated by the neuropathic patient can be seen in the screen captures below. The patient is instrumented with the F-Scan insole and asked to walk in his normal footwear. The highest pressures are indicated by the color red. Figure 1 summarizes the peak pressures generated during a representative foot strike. Note the excessive pressures generated at the metatarsal heads. In Figure 2, we see the same foot responding to an orthotic device. The orthosis has redistributed pressure into the arch and has relieved the pressure in the 2nd MTJ area. The F-Scan clearly shows the intended effect of the orthotic in relieving pressures at the second MTJ. It also shows the unintended effects of excessively loading the base of the 5th metatarsal.

The F-Scan enables the practitioner to improve his orthotic solution by minimizing the impact on alternative areas before further damage occurs. Beyond the physical representation of the pressure points on the foot, the F-Scan software can also represent an analysis of time/pressure relationship, as seen in the graph in Figure 3. The graph quantifies the visual information, as the line in the graph indicates. The graph confirms the higher pressures of Figure 1, in which the patient was without the orthotic.

The F-Scan system presents dynamic information frame-by-frame or in a variety of summary screens; each gives you new insights into the functional characteristics of your patient's foot. The F-Scan system naturally serves as an excellent patient education device and as a permanent medical record, while enhancing your ability to anticipate and alleviate high risk areas.

This case study focuses on the F-Scan's ability to provide important considerations for proper orthotic construction by identifying prominent high-pressure areas.

A 62 year old arborist presents with a two week history of an ulcer under the right 5th metatarsal head. He has had Insulin-dependent Diabetes Mellitus for many years. He has had known Diabetic Neuropathy in both feet for 10 plus years. He had an amputation of the right hallux five years ago, the right 2nd toe two years ago, and has had various ulcers under the 2nd MPJ, right foot. Examination revealed a partial thickness ulcer under the right 5th metatarsal head. The foot was edematous, hot and ruboric. Pedal pulses were in order. Culture revealed abundant Staph. Aureus. Initial treatment was debridement of ulcer, bed rest, local dressings of gantricin cream and one gram of Ciptro. Healing took three weeks and finally new orthotics, consisting of direct mold, full-length, cross-linked closed-cell polyethylene Ipos Form, were dispensed. An F-Scan examination was conducted pre-orthotic to determine all elevated pressure areas. The F-Scan evaluation revealed an extraordinary amount of pressure under the 1st and 2nd MTJs, with high and persistent pressure beneath the 5th MTJ on the right foot. An orthotic device was fabricated to alleviate all prominent pressure areas.

Reduced pressures at all sites indicated by F-Scan pre- and post-orthotic test comparison.

Post-orthotic F-Scan evaluation showed that all the inordinate forces and pressures were diminished to a great degree. Local pressures, as well as the duration of those pressures, were significantly reduced in the area of the 5th MTJ. Beyond the visual representation of the pressure points on the foot, the F-Scan software provides a graphical analysis of time/pressure relationships. The graph assists the clinician in quantifying both the values of the highest pressure and the time spent in any given area.

Peak pressure and duration of pressure significantly reduced on 5th MTJ.

This case study focuses on the F-Scan's ability to identify the unintended effect of pressure redistribution to a secondary high-risk area.

5.9% of the American population suffers from diabetes today, and an estimated 5.4 million people have not yet been diagnosed. Since approximately 2 million Americans with diabetes suffer from foot ulcers, proper patient screening and examination are crucial in preventing further complications, including nerve damage or even amputation.

The F-Scan system enhances your ability to obtain information concerning the diabetic foot, as well as other pathologies associated with the neuropathic foot. In this case study, the F-Scan system qualitatively and quantitatively displays the effect of the orthotic device in relieving and redistributing pressures to secondary sites along the plantar surface. The F-Scan system provides both the practitioner and the patient with easy-to-interpret data that shows the dynamic weight transfer with and without the orthotic.

The pressure profile generated by the neuropathic patient can be seen in the screen captures below. The patient is instrumented with the F-Scan insole and asked to walk in his normal footwear (far left). The highest pressures are indicated by the color red. Note the excessive pressures generated at the 1st and 2nd metatarsal heads. Subsequently, we see the same foot tested with an orthotic device (right). The orthotic has redistributed pressure into the arch and has relieved the pressure in the 2nd MTJ area. The F-Scan clearly shows the intended effect of the orthotic in relieving pressures at the second MTJ. It also shows clearly the unintended effects of significantly loading the base of the 5th metatarsal. The F-Scan enables the practitioner to improve his orthotic solution by minimizing the impact on alternative areas before further damage can occur. The F-Scan system presents dynamic information frame-by-frame or in a variety of summary screens - each gives you new insights into the functional characteristics of your patient's foot. The F-Scan system naturally serves as an excellent patient education device and as a permanent medical record, while enhancing your ability to anticipate and treat high-risk areas.

This case study focuses on the F-Scan's ability to provide important dynamic information for proper orthotic construction by identifying additional prominent high-pressure areas.

The patient is an Insulin-dependent diabetic with peripheral neuropathy. The right foot has had numerous procedures, including complete amputation of all toes in prior years, and 5th MTJ resection 4 weeks prior to the F-Scan test. The initial orthotic was designed to minimize pressures in the area of the 5th MTJ.

The initial F-Scan test was conducted inside the patient's custom-molded shoe without an orthotic. The test provided information for a baseline comparison. The figure below represents a single frame of a gait cycle, showing the peak pressure that was attained and its location. Test results indicate moderate pressures on the 5th MTJ. The test also showed elevated pressures on the 4th MTJ.

Prior to the initial F-Scan test, an orthotic was fabricated using a cut out sub-5th MTJ to further alleviate pressures. The device did not take into account the information provided by the F-Scan test when initially fabricated. A second F-Scan test was conducted with this custom orthotic placed in the molded shoe.

The results indicate further reduction in pressures sub-5th MTJ as expected. More problematic, however, were the elevated pressures under the 4th MTJ and the distal bony prominence due to the prior amputation. The elevated pressures on the 4th MTJ, combined with a high vertical impulse load on the bony prominence, would have introduced further complications. The F-Scan information significantly changed the approach utilized by this clinician.

This case study focuses on achieving an optimal combination of post-operative footwear and orthotics for protecting a wound.

The patient presents as an Insulin-dependent diabetic with neuropathy. An ulcer was present sub-2nd MTJ. The patient was tested in a soft athletic shoe (Figure 1), a post-operative shoe (Figure 2), and a combination post-operative shoe and a rocker bottom orthotic. For this patient, optimal results were achieved through the combination of post-operative shoe and rocker bottom orthotic. Adjustments were made to the rocker to optimize its position. A 68% reduction in pressure at the wound site was realized.