Project I - Background Worksheet Team Members: Kira Brown, Paige Fallu Clinical problem Diabetic Foot Ulcers 1) Strategic Focus based on the Strategic focus powerpoint presentation and readings a. Team name: Trango Tower b. Mission: We are dedicated to improving the lives of diabetic patients with insight, empathy, and passion through our continuing knowledge of needs and engineering. c. Vision: To create a removable off-loading device that is comfortable for the patient to wear, easy for the doctor to use, and heals neuropathic diabetic foot ulcers. d. Team Strengths: Courses taken (Biomechanics, tissue engineering, statics and dynamics), communication, teamwork, research, time management, documentation e. Team Weaknesses: Prototype design, knowledge of materials. f. Acceptance criteria for the team i. Interested in using an offloading device to heal neuropathic diabetic foot ulcer designed in a Class I or Class II setting. ii. Not interested in preventative care, diagnosing ulcer grade, or Class III devices. 2) Needs Exploration a. Contact with Podiatrist Dr. Chris Fallu i. Suggested improving insole off-loading device PegAssist by DARCO b. Healing of diabetic foot ulcers using removable off-loading devices has less pressure relief, leading to longer healing time, compared to non-removable devices. Removable device to heal diabetic foot ulcers Improve quality of foot ulcer insoles Improve the pressure relief/offloading of removable devices Reduce the time to heal diabetic foot ulcers Comfortable off-loading device Create a more prescribable off-loading device for doctors and patients Removable device allows Doctor to check the ulcer
3) Disease State Fundamentals -based on the Disease-State-Fundamentals powerpoint presentation and readings briefly answer the following questions: a. Anatomy and Pathophysiology i. Describe the normal anatomy and physiology: The sole of the foot is the bottom side of the foot, on which one walks. It is anatomically named and referred to as the plantar aspect. The plantar aspect is comprised of some of the thickest layers of skin on the human body due to the continuous loading and off-loading in addition to the friction produced when walking. There are two main nerves that branch from the tibial nerve and make up the sole of the foot from the arch to the toes. The first is the medial plantar nerve that ranges from the arch of the foot to the first three toes. The second is the lateral plantar nerve, which runs from the outer arch of the food to the fourth and fifth toes. These nerves are the main branches responsible for feeling from the arch to the tip of the toes. ii. Describe the disease function, causal factors, and disease progression: Neuropathic plantar ulcers affect patients with both Type I and Type II diabetes who are also diagnosed with neuropathy. The ulcerations usually occur on the aspects under the metatarsal heads, also known as the ball of the foot, or at the aspect of the toe. The most common cause of ulceration is repetitive mechanical forced in the gait that leads to callusing, an early sign of ulceration. The ulcer is formed from the callus pressing against the soft tissues within the foot. The callus is not removed, then the cells within the tissue will lyse and develop hematomas under the callus. This results in a small cavity filled with fluid with the appearance similar to a blister under the callus. The removal of the callus shows the ulcer. There are several different wound classifications with diabetic neuropathic foot ulcers: Wagner-Meggitt, University of Texas system, The S(AD) SAD, International Working Group on the Diabetic Food PEDIS, and the Infectious Diseases Society of America. The Wagner-Meggitt classification is what will be used primarily. It consists of grading the wound and scoring it as a number between 0-6 as described: grade 0 (intact skin), grade 1 (superficial ulcer), grade 2 (deep ulcer to tendon, bone, or joint), grade 3 (deep ulcer with abscess or osteomyelitis), grade 4 (forefoot gangrene), and grade 5 (whole foot gangrene). b. Clinical Presentation, Outcomes and Epidemiology i. Describe a typical clinical presentation associated with this disease/condition Typical clinical presentations are: Symptoms: Hypesthesia: Diminished capacity for physical sensation, especially of the skin Hyperesthesia: Excessive physical sensitivity, especially of the skin Paresthesia: Burning or prickling sensation in the foot,
usually painless. Dysesthesia: Unpleasant or abnormal sense of touch, described as pain. Radicular Pain: pain that radiates (travels) into lower extremity directly along the course of a spinal root nerve. Anhydrosis: failure of the sweat glands. Examination: Weight bearing areas, such as: heel, plantar metatarsal head areas, and tips of toes. Areas subjected to stress, such as: dorsal portion of hammer toes. Other findings: Hypertrophic calluses: enlargement of a tissue (callus) as a result of an increase in size versus the number of constituent cells. Brittle nails Hammer toes: Muscle and ligament imbalance around the toe joint that causes the middle joint to bend and become stuck in that position. Fissures: A breakage made by crackling or splitting that is long and narrow. The foot is warm, good blood supply (well perfused) with pulses felt at artery site (palpable pulses). ii. Profile the patient state associated with a disease: Patient has Diabetes (Type I or Type II) and neuropathy in lower extremities. iii. Assess clinical outcomes and Epidemiology: Clinical outcomes: Management of wound by: Wound control: removal of callus and non-viable tissue Mechanical control: Redistribute plantar pressures. Most effective way is by use of total contact cast technique Use of prefabricated boot. Microbiological control: Deep swab and tissue samples collected. Antibiotics given for possible presence of Gram-negative, Gram-positive, and anaerobic bacteria. Metabolic control:
Glycaemic control is essential to healing since wound healing and neutrophil is impaired by diabetes. Epidemiology: In a study by the American Diabetes Association: In a population of 8,905 patients with either Type I or Type II diabetes: 514 patients developed a foot ulcer over 3 years of observation (5.8%). 77 patients developed bone infection (osteomyelitis) (15%) 80 patients required amputation (15.6%). Survival at 3 years is72%. Survival at 3 years for a diabetic group of the same age and sex is 87%. iv. Estimate the Morbidity, Mortality, and Prevalence of this condition: Morbitiy: In 2016, Diabetes affected 382 million people worldwide. Expected to rise over 552 million by 2030 Neuropathy is estimated to affect 50% of the diabetic population 191 Million people worldwide 85% of lower limb amputations in diabetic patients are preceded by a foot ulcer Mortality: In a study by Brownrigg, crude mortality rates in diabetic groups: With diabetic foot ulceration: 27% Without diabetic foot ulcerations: 6.4% Prevalence: 8.3-9.9% of the adult population worldwide are affected by diabetes. 4.1-5% with neuropathy c. Evaluate the Economic Impact i. Estimate the overall cost of the disease on society/health care-system According to a study by the American Diabetes Association: Cost of males age 40-65: $27,987 for 2 years after diagnosis.
4) Existing Solutions a. Existing Solutions - Non-Removable i. Total contact cast (TCC) the gold standard for healing DFU Healing : Healing rate of 88.9% Takes approximately 5.4 weeks to heal 85% pressure relief Advantages: Healing rate and time Offloading distribution Inexpensive Disadvantages: Joint stiffness and muscle atrophy Possibility of new ulcerations and skin breakdown Labor intensive application and takes time to create and fit Possible laceration of patient during cast removal Cannot inspect ulcer without full removal Non-removable cast can be difficult for the patient to do everyday activities Not beneficial for obese patients Vascularity must be evaluated b. Existing Solutions - Removable i. Charcot Restraint Orthotic Walker (CROW) is made for Charcot disease but can be used for diabetes Healing rate of 50% Takes approximately 7.5 weeks to heal 55% pressure relief Ability to inspect and treat ulcer by removing Minimal joint stiffness and atrophy Patient satisfaction by being able to remove Can utilize growth factors and other topical medications and dressings Because the patient can remove, does not mean they always wear it Skin irritation and breakdown Needs to be worn over a support stocking or knee-high cotton hose Requires frequent adjustments ii. Insole systems like Peg Assist by DARCO, a peg system that are removed where the injury is located
33-60% pressure relief Can be ordered online and patients can do at home Good pressure relief for insoles Easy to use Comfortable Pegs fall out Some cases caused more pressure and lead to injury Some ruined after first use Some did not fit right Can dorsiflex ankle iii. Orthowedge is a half shoe that only has a sole under the toes and sole of the foot. The only part of the shoe that makes contact with the ground is heal and middle of the foot. Healing rate of 58% Takes approximately 7.5 weeks to heal 64-66% of pressure relief Can be combined with insoles to increase pressure relief Removable More comfortable than TCC Pressure is displaced to midfoot and heel, not evenly distributed Can dorsiflex ankle Open toed shoe can lead to more injury to skin iv. Integrated Prosthetic and Orthotic System (IPOS) is a rocker shoe that is lifted at the heel and toes Healing rate of 55% Takes approximately 7.5 weeks to heal 55-65% pressure relief Forefoot does not contact the ground Inexpensive Comfortable, high patient compliance for the ones who can walk in it Removable Patients must have good balance, if not they cannot wear Requires dorsiflexion
v. Healing Sandal is a total contact orthotic that contains a cutout under the ulcer Healing rate of 74% Takes approximately 7.5 weeks to heal Lightweight design More aesthetically pleasing High patient compliance Less environmental protection Open toed shoe can lead to more injury to skin Poor control of foot motion Dorsiflexion is possible b. Gap analysis A removable device that does not allow dorsiflexion, has >75% pressure relief, even offloading distribution, < 6 weeks to heal, aesthetically pleasing and has high patient and doctor compliance. 5) Stakeholder Analysis a. Stakeholders i. Doctors Podiatrist, Primary Care Provider, Family Doctor ii. Patients Diabetic patients with neuropathy iii. Caregivers Family members, spouse, in-home RN, nursing home RN b. Stakeholder conflicts For current solutions, most patients do not want a total contact cast because it is non-removable and can be uncomfortable. Because of this, the other options can lead to safety issues. Rocker bottoms are difficult to walk in for obese and/or elderly patients because they must have good balance. It can also be difficult if there are caregivers to help the patient walk around with a shoe or boot on for the next few months. c. Decision maker The Doctor makes the decision on the care route but ultimately, the patient is since they decide if they want to wear the boot/shoe. d. Continuum of Care 1. Patient goes to Podiatrist/Doctor 2. Both feet to check for ulcers, cuts and abrasions, signs of poor circulation, and areas of numbness. 3. Depending on severity, boot/shoe is prescribed
4. Must wear boot/shoe for 2-4 months 5. Check up on foot ulcer at every appointment, times depend on severity 6) Market Analysis a. Current market landscape: i. Market to podiatrist and physicians ii. Submarket to patients b. Describe market segments: i. Pre-diagnosis: Monitoring for callus or blistering of the plantar aspect Monitoring of danger signs: swelling, pain, color change, breaks in skin. ii. Diagnosis: Removal of callus Expose ulcer iii. Post-diagnosis: Weight distribution (off-loading) of ulcer site. Total contact cast Air boot Cushioning insole Teaching of ulcer care: rest, footwear, regular dressings and changes, frequent observation for signs of infection. iv. After healing: Patient fitted with a cradled insole and shoes to prevent occurrence. c. Define market size, growth, and competitive dynamics of each segment i. Size: In 2016, Diabetes affected 382 million people worldwide. ii. Growth: Diabetes is expected to affect 552 million people by 2030 iii. Competitive dynamics: More competitive during the post-diagnosis segment. d. Describe to what extend stakeholder needs are being met in each segment i. Pre-diagnosis: Affects patients and caregivers ii. Diagnosis: Affects patient and doctor iii. Post-diagnosis: Affects patient, doctor, and caregiver iv. After healing: Affects patient and caregivers e. List key considerations for choosing a target market i. Comfortable and easy to wear/use
ii. Cost effective iii. Removable iv. Customizable Foot size Ulcer size Ulcer site v. Heals ulcer in less than 40 days vi. About 70% pressure relief by off loading vii. Infection prevention