The effect of diabetes mellitus on the material properties of the distal tibia.
Finalist Journal of Foot and Ankles Surgery's "Awards of Excellence 2002"
Journal of Foot and Ankle Surgery: 2003

The alterations of bone and mineral metabolism created by diabetes may lead to weakening of bone, thereby rendering the diabetic patient more susceptible impaired fracture healing. Previous studies have demonstrated alterations of bone and cartilage in diabetic patients, which may adversely affect their strength and integrity. This investigation evaluates the effects of diabetes on the mechanical properties of human bone, specifically the tibia. Seven diabetic and seven non-diabetic human (male) cadaveric distal tibiae were used in this study. The average age of diabetic cadaveric samples was 51 years, while the average age of non-diabetic samples was 75 years. Three-point bending tests for the strength and stiffness were performed. Each specimen was loaded at a constant rate of 10mm/min until failure. From the recorded curve of load versus displacement, the ultimate and yield strength and bending modulus of bone were calculated. Overall, the values for non-diabetic bone samples were greater than those of diabetic samples, however no significant differences were found in the elastic modulus, yield and ultimate strength, and fracture toughness between the samples tested. The current investigation demonstrates that diabetic tibial bones have strength and stiffness similar to non-diabetic from a patient population much older. Specifically, the bones of the tibia behave similar to those of a patient population 24 years older, leading to the speculation that diabetes has an effect similar to that of aging on the musculoskeletal system.

Reproducibility of gait analysis variables: one-step versus three-step method of data acquisition.
Journal of Foot and Ankle Surgery: July/Aug 2002

The purpose of the study was to evaluate the preciseness and repeatability of EMED-SF platform data collection using two different protocols. Gait variables of five healthy women and five men, with an average age of 27.3 +/- 3.2 years, weighing 67.5 +/- 13.3 kg, were evaluated. With a one-step and a three-step approach of data collection, peak pressure, pressure-time integral, and contact time were measured. Peak pressures were not significantly different between both methods. Significant differences were found between both methods in total contact time and pressure-time integral. Both methods were comparable in peak pressures (error between methods = 7.0), while the one-step protocol was more repeatable (intraclass correlation coefficient = 0.59) than the three-step protocol (intraclass correlation coefficient = 0.36). The error between methods for total contact time and pressure-time integral were 143.3 and 50.1, respectively, suggesting that the two protocols lead to different results. The one-step protocol (intraclass correlation coefficient = 0.40) had a higher repeatability than the three-step protocol (intraclass correlation coefficient = 0.31). The one-step protocol has some advantages over the three-step protocol as far as repeatability, simplicity, convenience, and time conservation are concerned. For measuring total contact time and pressure-time integrals, both methods have comparable repeatability, although the protocols lead to different outcomes.

The diagnosis of osteomyelitis in diabetes using erythrocyte sedimentation rate: a pilot study.
Gold Award, William J. Stickel Awards for Research and Papers in Podiatric Medicine 1997
Journal American Podiatric Medical Association: October 2001

Osteomyelitis secondary to diabetic foot infections can lead to proximal amputation if not diagnosed in a timely and accurate manner. The authors have found no studies to date that correlate a specific erythrocyte sedimentation rate with osteomyelitis. A retrospective chart review of 29 diabetic patients admitted to the hospital with diagnoses of osteomyelitis or cellulitis of the foot during a 1-year period was performed. Of the various lab values and demographic factors compared, erythrocyte sedimentation rate was the only measure that differed significantly between the two groups. A receiver operating characteristic curve was used to obtain the optimal cutoff value of 70 mm/h, a level above which osteomyelitis was present with the highest sensitivity (89.5%) and highest specificity (100%), along with a positive predictive value of 100% and a negative predictive value of 83%. This study shows that in combination with clinical suspicion in diabetic foot infections, the erythrocyte sedimentation rate is highly predictive of osteomyelitis, and that the value of 70 mm/h is the optimal cutoff to predict accurately the presence or absence of bone infection.

Electric stimulation as an adjunct to heal diabetic foot ulcers: a randomized clinical trial.
Archives of Physical Medicine and Rehabilitation: June, 2001

OBJECTIVE: To evaluate high-voltage, pulse-galvanic electric stimulation as an adjunct to healing diabetic foot ulcers. DESIGN: Randomized, double-blind, placebo-controlled pilot trial. SETTING: University medical center. PATIENTS: Forty patients with diabetic foot ulcers, consecutively sampled. Twenty patients each assigned to treatment and placebo groups. Five patients (2 treated, 3 placebo) withdrew because of severe infection. INTERVENTIONS: Electric stimulation through a microcomputer every night for 8 hours. The placebo group used identical functioning units that delivered no current. Additional wound care consisted of weekly debridements, topical hydrogel, and off-loading with removable cast walkers. Patients were followed for 12 weeks or until healing, whichever occurred first. MAIN OUTCOME MEASURES: Proportion of wounds that healed during the study period. Compliance with use of device (in hr/wk), rate of wound healing, and time until healing. RESULTS: Sixty-five percent of the patients healed in the group treated with stimulation, whereas 35% healed with placebo (p = .058). After stratification by compliance, a significant difference was identified among compliant patients in the treatment group (71% healed), noncompliant patients in the treatment group (50% healed), compliant patients in the placebo group (39% healed), and noncompliant patients in the placebo group (29% healed, linear-by-linear association = 4.32, p = .038). There was no significant difference in compliance between the 2 groups. CONCLUSION: Electric simulation enhances wound healing when used in conjunction with appropriate off-loading and local wound care.

The effects of diabetes on the mechanical properties of human cartilage.
Clinical Orthopaedics and Related Research: November 1999

Metabolic changes due to diabetes mellitus have their effect on nearly every organ system in the body. This includes the articular cartilage in the tibiotalar joint. A number of degenerative changes have been associated with diabetes mellitus, such as osteoporosis, osteoarthritis, and limited joint mobility. Much of the existing work that describes the effect of diabetes on cartilage is based on animal models. This study was performed in human cadaveric ankle joints. Articular cartilage in fifteen diabetic and non-diabetic fresh-frozen human ankle joints was tested for its biomechanical properties, which are the aggregate modulus, Poisson's ratio, the shear modulus and the permeability. Significant differences were found between diabetic and non-diabetic specimen. This study demonstrated that, overall, non-diabetic cartilage had a larger aggregate modulus and a larger shear modulus. Overall, permeability and Poisson's ratio showed to be higher in diabetic cartilage. These results indicate that significant differences exist in biomechanical properties between diabetic and non-diabetic ankle cartilage, and may suggest that clinically observed pathologies in some patients may be associated with the presence of diabetes mellitus.

Medial column tendon procedures for the treatment of posterior tibial tendon dysfunction.
Clinics in Podiatric Medicine and Surgery: July 1999.

The treatment of patients with posterior tibial tendon dysfunction remains driven by preference of the surgeon with little science to guide the surgeon. The use of tendon procedures, such as tendon decompression, tenodesis and tendon transfers of the posterior muscle group either alone or in combination with other procedures are popular treatment options. Controversy remains in procedure selection, and in the specific techniques of each procedure. A great deal of study is needed to identify the best technique for each stage of the deformity. The authors review the tendinous procedures currently used for the treatment of posterior tibial tendon dysfunction.

Use of postoperative steroids to reduce pain and inflammation.
Journal of Foot and Ankle Surgery: May/June 1999

Postoperative injection of a steroid is used by many podiatric surgeons to reduce pain and inflammation after foot surgery. The authors present a review of the literature on postoperative steroid use from many medical specialties as well as a review of wound and bone healing. The literature indicates that using a steroid is a safe and effective means to reduce postoperative pain and edema. Studies have shown steroids to delay healing, inhibit collagen synthesis, and increase the risk of postoperative infection. No author reported a delay in wound or bone healing or increased infection rate in patients in which a steroid was used. Although there is literature to support this practice, many questions remain and further investigation is needed.

The effects of diabetes mellitus on the material properties of human metatarsal bones.
Journal of Foot and Ankle Surgery: May/June 1998.

While some investigations have focused on the effect of diabetes on the material properties of connective tissue in both the human and animal model, no study to date has investigated the effects of the disease process on human metatarsal bones. This investigation compared the material properties of human metatarsal bones from young diabetic donors (51.3 +/- 8 years) and older nondiabetic donors (72.3 +/- 10 years). Our results demonstrated no significant differences between the two groups. This would seem to suggest that the effects of aging are comparable to the effects of diabetes on the structural integrity of human metatarsal bones.

Choosing a practical screening instrument to identify patients at risk for diabetic ulceration.
Archives of Internal Medicine: February 9, 1998.

OBJECTIVE: To evaluate the sensitivity and specificity of 3 sensory perception testing instruments to screen for risk of diabetic foot ulceration. METHODS: This case-control study prospectively measured the degree of peripheral sensory neuropathy in diabetic patients with and without foot ulcers. We enrolled 115 age-matched diabetic patients (40% male) with a case-control ratio of approximately 1:3 (30 cases and 85 controls) from a tertiary care diabetic foot specialty clinic. Cases were defined as individuals who had an existing foot ulceration or a history of a recently (< 4 weeks) healed foot ulceration. Controls were defined as subjects with no foot ulceration history. Using receiver operating characteristic analysis, we evaluated the sensitivity and specificity of 2 commonly used nephropathy assessment tools (vibration perception threshold testing and the Semmes-Weinstein 10-g monofilament wire system) and a 4-question verbal neuropathy score to evaluate for presence of foot ulceration. RESULTS: A vibration perception threshold testing using 25 V and lack of perception at 4 or more sites using the Semmes-Weinstein 10-g monofilament wire system had a significantly higher specificity than neuropathy score used. The neuropathy score was most sensitive when 1 or more answers were affirmative. When modalities were combined, particularly the monofilament wire system plus vibration perception threshold testing and the neuropathy score plus the monofilament wire system, there was a substantial increase in specificity with little or no diminution in sensitivity. CONCLUSIONS: The early detection of peripheral neuropathy or loss of "protective sensation" is paramount to instituting a structured treatment plan to prevent lower extremity amputation. The results of our study suggest that all 3 sensory perception testing instruments are sensitive in identifying patients at risk for ulceration. Combining modalities appears to increase specificity with very little or no diminution in sensitivity.

Practical criteria for screening patients at high risk for diabetic foot ulceration.
Archives of Internal Medicine: January 26, 1998.

BACKGROUND: A comprehensive understanding of clinical risk factors for developing foot ulcerations would help clinicians to categorize patients by their risk status and schedule intervention resources accordingly to prevent amputation.
OBJECTIVE: To evaluate risk factors for foot ulcerations among persons with diabetes mellitus.
METHOD: We enrolled 225 age-matched patients, 46.7% male, with a ratio of approximately 1:2 cases: controls (76 case-patients and 149 control subjects). Case-patients were defined as subjects who met the enrollment criteria and who had an existing foot ulceration or a recent history of a foot ulceration. Control subjects were defined as subjects with no history of foot ulceration. A stepwise logistic regression model was used for analysis.
RESULTS: An elevated plantar pressure (> 65 N/cm2), history of amputation, lengthy duration of diabetes (> 10 years), foot deformities (hallux rigidus or hammer toes), male sex, poor diabetes control (glycosylated hemoglobin > 9%), 1 or more subjective symptoms of neuropathy, and an elevated vibration perception threshold (> 25 V) were significantly associated with foot ulceration. In addition, 59 patients (78%) with ulceration had a rigid deformity directly associated with the site of ulceration. No significant associations were noted between vascular disease, level of formal education, nephropathy, retinopathy, impaired vision, or obesity and foot ulceration on multivariate analysis.
CONCLUSIONS: Neuropathy, foot deformity, high plantar pressures, and a history of amputation are significantly associated with the presence of foot ulceration. Although vascular and renal disease may result in delayed wound healing and subsequent amputation, they are not significant risk factors for the development of diabetic foot ulceration.

Is postural instability exacerbated by off-loading devices in high risk diabetics with foot ulcers?
Ostomy Wound Management: January 1998.

Background and Purpose: Pressure reduction is pivotal to heal diabetic ulcers. No work has evaluated the effect off-loading devices on postural stability (PS) in high risk diabetics.
Subjects: Our aim was to compare PS associated with 5 off-loading strategies: total contact casts with cast boot (TCB), total contact casts with heel (TCH), removable walking casts (EZ), half-shoes, and canvas shoes (CVO) using a repeat measure design.
Methods: We studied 24 diabetics with foot ulcers using the F-Scanä pressure platform. PS was measured as total deviation of center of force. We evaluated three 30 second trials using Tukey's Studentized range test for multiple comparison (a = 0.05).
Results: PS was significantly greater with TCH compared to EZ and CVOs.
Conclusion and Discussion: While total contact casts remains the gold standard to treat neuropathic ulcers, care should be used when placing diabetic patients in any device which might lead to further instability.

Electrical Stimulation and Wound Healing: A Review of the Current Literature.
Journal of Foot and Ankle Surgery: November/December 1997.

The authors present a review of the current literature regarding electrical stimulation with special focus on the merits of its uses in wound healing. Literature from a basic science, animal studies and clinical investigations are reviewed. The literature seems to suggest that electrical stimulation can effect wound healing, but the method of delivery remains uncertain.

Off-loading strategies of the neuropathic ulceration.
Bronze Award, William J. Stickel Awards for Research and Papers in Podiatric Medicine 1997;
Journal of the American Podiatric Medical Association: October, 1997.

High pressure on the sole of the foot has been identified as an important causative factor in the development of neuropathic ulcers in persons with diabetes mellitus. There is little scientific data to compare the effectiveness of commonly used modalities to reduce these areas of high pressure. Our aim was to compare the effectiveness of total contact casts (TCC), half-shoes (HS), rigid soled post-operative shoes (RSS), accommodative felt and polyethylene foam padding (AD), and removable walking casts (RWC) to reduce peak plantar foot pressures at the site of neuropathic ulcerations in diabetics. We compared the reduction in peak pressures at ulcer sites under the great toe (n=7) and ball of the foot (n=19) using the 5 treatments described above. A rubber soled canvas oxford shoe was used to establish baseline pressure values. With the Novel Pedar in-shoe pressure measurement system, data from 32 mid-gait steps was collected for each treatment. Evaluation of mean peak pressure and percent change from baseline was carried out for analysis. We used Tukey's Studentized Range Test for simultaneous multiple comparisons between treatments with an a =0.05. RWCs reduced plantar pressures significantly better than other treatments for ulcers under the ball of the foot. For great toe ulcers, TCCs and RWCs reduced pressure better than the other treatments. There was a consistent pattern in the ability of the devices evaluated to effectively reduce foot pressures at ulcer sites. Removable cast walkers were as effective or more effective than TCCs. Half-shoes were consistently the third most effective modality followed by accommodative dressings and post-operative shoes. Clinical studies are needed to fully evaluate healing times, complications and patient satisfaction.

Is Electrical Stimulation Effective in Reducing Neuropathic Pain in Patients with Diabetes?
Journal of Foot and Ankle Surgery: July/August 1997.

Pulsed-dose electrical stimulation is evaluated as an analgesic modality in patients-with painful diabetic neuropathy. Using a knitted silver-plated nylon/dacron stocking electrode, patients were given electrical stimulation over the course of 1 month. Pain was measured weekly, using a 10-cm. visual analog scale. Pain measurements at the end of the 4-week therapy and at 1 month after complete discontinuation of therapy were significantly lower than at the initiation of therapy. The results of this pilot study suggest that nocturnal doses of pulsed-electrical stimulation may be effective in alleviating subjective, burning, diabetic neuropathic pain in a population consisting of patients with grossly intact protective sensation, relatively good distal vascular perfusion and less than ideal glucose control. To the authors' knowledge, this is the first analytic report of pulsed-dose electrical nerve stimulation delivered through a stocking electrode for treatment of symptomatic diabetic neuropathy in medical literature.

The natural history of great toe amputations.
Journal of Foot & Ankle Surgery: May/June, 1997.

The purpose of this study is to report the prevalence of reamputation following resection of the great toe and first ray in adults with diabetes. We abstracted the medical records of 90 diabetic great-toe and first-ray amputees admitted between 1981 and 1991. The most common etiologies of initial amputations were ulcer with soft tissue infection (39%), ulcer with osteomyelitis (32%), and puncture wounds (12%). Sixty percent of all patients had a second amputation, 21% had a third, and 7% had a fourth. Fifteen percent of the patients who had a second amputation had it contralaterally. Seventeen percent subsequently underwent a below-knee amputation and 11% had a Transmetatarsal amputation on the same extremity, 3% had a below-knee amputation, and 2% a transmetatarsal amputation contralaterally. The mean time from the first to the second amputation was approximately 10 months. The results of this study suggest that a large proportion of patients undergoing an amputation at the level of the great toe or first ray have subsequent amputations in the first year following the initial procedure. Additionally, it appears that the contralateral foot may be at significant risk for distal amputation following resection of the hallux or first ray.

Puncture wounds: soft tissue and bone infections in children.
Western Journal of Medicine: February, 1997.

We report on the prevalence of osteomyelitis, the prevalence of soft tissue infections, and the type and number of pathogens encountered in bone and soft tissue infections caused by puncture wounds in children. In addition, we seek to establish whether shoe gear plays a role in the flora in infected puncture wounds and if laboratory indices are indicative of the presence of infection. The group consisted of 44 nondiabetic children admitted to hospital for puncture wounds of the foot. Cultures were positive for osteomyelitis in 7 patients (16%), all involving the forefoot (P < .04). The most common pathogen in soft tissue infections was Staphylococcus aureus. The most common pathogen in osteomyelitis was Pseudomonas aeruginosa. There was no significant difference in the prevalence of osteomyelitis and soft tissue infection based on footwear. There were no cases of osteomyelitis encountered among barefoot children (P < .04). In 10 cases (83%), P aeruginosa infection (both soft tissue and bone) occurred while the patients were wearing tennis shoes (P < .04). In this study, the leukocyte count (normal in 29 patients [66%]), erythrocyte sedimentation rate (normal in 28 patients [64%]), and temperature (normal in 44 patients [95%]) did not have any predictive value in differentiating soft tissue infection from osteomyelitis in children.

Psoriasis and Elective Foot Surgery.
Honorable Mention, American Society of Podiatric Dermatology Resident Writing Competition;
Journal of Foot and Ankle Surgery: July/August 1996.

The authors present a brief overview of the dermatologic condition, psoriasis. Special attention is given to a review of the literature as it addresses surgery and the psoriatic patient. The authors conclude that psoriatic patients are somewhat more susceptible to postoperative infection, but with proper precautions, complications can be avoided. Therefore, the condition of psoriasis is not an absolute contraindication to elective foot surgery.

Complications of distal first metatarsal osteotomies.
Journal of Foot & Ankle Surgery: November/December, 1995.

University of Texas Health Science Center at San Antonio, USA. Many surgical procedures have been described for the correction of hallux valgus and hallux limitus deformities. Distal first metatarsal osteotomies have been advocated since the turn of the century, and have been modified and improved since that time. Various complications have been associated with distal osteotomies, but there is infrequent reference to the normal changes in joint function, foot biomechanics, and forefoot pressures after surgery. The following literature review addresses the postoperative effects of decreased first metatarsophalangeal joint motion, shortening of the first metatarsal, dorsal displacement of the capital fragment, and transfer metatarsalgia on foot function.

Avascular Necrosis of the Hallucal Sesamoids: A Review of Literature.
Second Place in the Dr. Howard Reinherz Excellence in Medical Writing competition, 1995;
Journal of Foot and Ankle Surgery: July/August, 1995.

The authors present a literature review and systematic approach to the diagnosis and treatment of avascular necrosis of the sesamoids of the flexor hallucis brevis tendon. Renander, in 1924, was one of the earliest authors to call attention to this condition. Since that time, many other authors have written about this entity, some even questioning its existence. Many different treatment regimes have been postulated, encompassing both the conservative and surgical modalities. Most literature advocates attempted conservative treatment followed by surgical excision, only if conservative methods fail.

Lower extremity manifestations of vibrio vulnificus infection.
Journal of Foot & Ankle Surgery: July/August, 1995.

Vibrio vulnificus is a potentially lethal marine bacterium that has not been previously described in podiatric literature. A review of the microorganism's characteristics, susceptible patient population, and lower extremity manifestations of infection is presented. V. vulnificus is found as part of the normal flora of the Gulf of Mexico, Atlantic, and Pacific coastal waters and is often isolated from the filter feeding shellfish of these regions. Its pathogenicity is generally reserved for the immunocompromised host, and is specifically related to disease states which exhibit high serum iron levels. V. vulnificus infections present in two distinct clinical syndromes: primary sepsis secondary to raw oyster ingestion, or localized infection from wound exposure to V. vulnificus-inhabited salt water. Both syndromes demonstrate characteristic skin lesions of the trunk and extremities that present as hemorrhagic bullae and progress to necrotic ulcerations. Although V. vulnificus infection is rare, its extreme virulence in patients suffering from a chronic disease process and its manifestation of characteristic lower-extremity lesions require the podiatric physician to be able to recognize and treat such a condition.

Identification and Treatment of the Diabetic Neuropathic Foot.
Journal of Foot and Ankle Surgery: January/February 1995.

The authors discuss neuropathic osteoarthropathy in the diabetic foot, often associated with Charcot joints. Identification of this malady as well as indications for treatment are reviewed. Representative cases are illustrated