Georgeanne Botek

Peak Plantar Pressure and Shear Locations: Relevance to diabetic patients

Diabetic foot ulcers burden the U.S. health care system with an annual cost of approximately

Charcot neuroarthropathy: An often overlooked complication of diabetes

6 billion (1). Based on the mechanical etiology of diabetic foot lesions, investigators tried to establish a relationship between ulcer occurrence and plantar pressures. Mostly, peak pressure has been chosen as an ulcer predictor. However, previous studies have yielded only moderate correlations between peak pressure and the occurrence of diabetic foot lesions (2–4). Surprisingly, in one study that examined whether plantar ulcer locations matched peak pressure sites (4), only 38% of the ulcers developed under the peak pressure area. Therefore, foot pressure was labeled as a “poor” predictor of diabetic ulcer occurrences and their location (3). Effectiveness of diabetic ulcer prediction and prevention depends on an understanding of plantar soft tissue mechanics and the complete nature of foot-ground interactions. Further investigation of plantar shear in addition to pressure is essential to minimize the neuropathic ulcer prevalence. The purpose of this study was to find whether the peak pressure and shear under the feet of diabetic patients occur at different locations. If confirmed, shear distribution may explain the deviation between peak pressure and ulcer locations and potentially help researchers design more effective interventions. Thirty volunteers were recruited, among whom 10 had diabetic neuropathy. The remaining nondiabetic subjects served as control subjects. Subjects with gross foot deformities (except minor toe clawing), prior foot surgeries, and …

Forefoot plantar shear stress distribution in hallux valgus patients.

In patients with long-standing, poorly controlled diabetes and peripheral neuropathy, a red, hot, swollen foot without open ulceration should raise the suspicion of Charcot neuroarthropathy, an often-overlooked diabetic foot complication. The authors discuss key diagnostic features and how to differentiate this condition from cellulitis, osteomyelitis, and other conditions. They review key elements of the workup and emphasize the importance of early diagnosis and prompt treatment to preserve a functioning foot. Suspect this condition if a patient with long-standing, poorly controlled diabetes and peripheral neuropathy develops a red, hot, swollen foot without ulceration.

Lower extremity amputation risk factors associated with elevated ankle brachial indices and radiographic arterial calcification.

BACKGROUND Hallux valgus is a common foot disorder often experienced with secondary callosities and metatarsalgia. Many factors including improper shoes might be responsible in the pathophysiology of the problem. Hallux valgus deformity has been shown to alter the biomechanics of the whole foot rather than affecting only the great toe. Due to changes in the biomechanical functioning of the first ray, other regions of the forefoot area have been shown to bear abnormal loads with increased vertical loading on medial, central and lateral forefoot regions. The purpose of this study was to investigate the pattern of forefoot plantar shear loading in hallux valgus patients and compare these results with those of control subjects. METHODS A total of 28 subjects were recruited for the study of which 14 were clinically diagnosed with hallux valgus. A custom built platform was used to collect peak pressure and shear data. A repeated measures analysis of variance was used to analyze the recorded data. FINDINGS Antero-posterior shear was significantly lower in the deformity group (p<0.05). The lateral forefeet of the patients, however, experienced slightly higher shear loads (p>0.05). INTERPRETATION Propulsive shear force generation mechanism under the medial forefoot was impaired in the disorder group. In general, shear loading of the plantar feet shifted laterally. Previously hypothesized higher medio-lateral shear magnitudes under the hallux were not confirmed.

Syndrome of painful legs and moving toes: a case study.

An elevated ankle brachial index (ABI) resulting from medial artery calcification, or Mönckebergs arteriosclerosis, is commonly seen in patients with diabetes mellitus or end-stage renal disease. Recent data have found an association between elevated ABIs and cardiovascular morbidity and mortality. The purpose of the present study was to evaluate the prognostic significance of high ABIs, poorly compressible arteries, and radiographic artery calcification compared with low ABIs in predicting lower extremity amputation and morbidity. A retrospective review was conducted of patients who had undergone a lower extremity amputation from July 1, 2011 to August 31, 2012. A total of 129 patients (140 lower extremity amputations) were categorized into 3 groups: a low ABI (<0.9), a normal ABI (0.9 to 1.3), and a high ABI (>1.3) or poorly compressible arteries. Of the 129 patients, 31 (22.14%), 36 (25.71%), and 73 (52.14%) were in group 1, 2, and 3, respectively. The prevalence of diabetes was greatest in group 2 (p = .016). A high percentage of radiographic arterial calcification was found in all 3 groups (p = .003). Statistically significant differences were also found in groups 1 and 3 for peripheral arterial disease (p < .001), chronic kidney disease (p < .001), coronary artery disease (p = .021), revascularization history (p < .001), and tobacco use (p = .012). A U-shaped relationship between the ABI and comorbidity was found, suggesting an elevated ABI is as equally prognostic as a low index in predicting the need for amputation.

Etiology, pathophysiology, and staging of hallux rigidus.

Painful legs and moving toes syndrome is characterized by spontaneous causalgic pain in the lower extremities associated with peculiar involuntary movements of the lower extremities, especially the toes and feet. The pain is diffuse, intractable, aching, and deep. The movements consist of persistent writhing movements in the digits that cannot be limited voluntarily. The syndrome has been observed after a variety of abnormalities affecting the posterior nerve roots, the spinal ganglia, and the peripheral nerves. This article reviews commonly reported findings and current concepts in the etiology and management of this condition.

Plantar Shear Stress Distribution in Patients with Rheumatoid Arthritis Relevance to Foot Pain

The condition of hallux limitus is well understood and agreed on as visualized histologically and radiographically. But the historically described pathophysiology and anatomy that predisposes to hallux limitus has been challenged. Numerous investigators have proposed anatomic abnormalities of the foot as a primary cause of this condition, but perhaps trauma is the only unanimously agreed on cause. However, this accounts for only a small percentage of cases. To strive for better treatment outcomes, understanding the pathophysiology, assessing patient risk factors, and recognizing causative agents can better equip the foot and ankle surgeon in managing this condition.

Biomechanical factors in diabetic foot disease

BACKGROUND Rheumatoid arthritis is an autoimmune disease that causes chronic, progressive joint inflammation; it commonly affects the joints of the feet. Biomechanical alterations and daily pain in the foot are the common outcomes of the disease. Earlier studies focusing on plantar pressure in such patients reported increased vertical loading along with peak pressure-pain associations. However, footwear designed according to the pressure profiles did not relieve symptoms effectively. We examined plantar shear and pressure distribution in patients with rheumatoid arthritis and compared the findings with those of controls, and we investigated a potential relationship between foot pain and local shear stresses. METHODS A custom-built platform was used to collect plantar pressure and shear stress data from nine patients with rheumatoid arthritis and 14 control participants. Seven patients reported the presence of pain under their feet. Pressure-time and shear-time integral values were also calculated. RESULTS Peak pressure, pressure-time integral, resultant shear-time integral, and mediolateral shear stress magnitudes were higher in the complication group (P < .05). An association between peak shear-time integral and maximum pain locations was observed. CONCLUSIONS Increased mediolateral shear stresses under the rheumatoid foot might be attributable to gait instability in such patients. A correlation between the locations of maximum shear-time integral and pain indicate the clinical significance of plantar shear in patients with rheumatoid arthritis.

Evaluating Iatrogenic Complications of the Total-Contact Cast: An 8-Year Retrospective Review at Cleveland Clinic.

Although the risk of vascular disease is markedly increasedin diabetes [1], it is the combination of altered vascularstatus and nerve damage that often leads to ulceration andamputation [2]. Important early studies by Brand and col-leagues [3] focused on elevated stress in a deformed, neu-ropathic limb as a causative factor in tissue breakdownand this has been a constant theme of experimental andanalytical studies to the present day.The stress component normal to the foot (usually calledplantar pressure) has typically been available for study [4]and this quantity is associated with the risk of future ulcer-ation [5]. We have shown it to be useful, together withfoot shape, in the design of pressure relieving footwear [6]and others have derived quantities such as pressure gradi-ent to indicate risk [7]. Recent studies of plantar shearstress [8] have reported higher neuropathic/control ratiosthan for plantar pressure, suggesting that shear stress mayhave an important role in tissue damage.The measurement of pressure between the foot and thefootwear is potentially very useful clinically [9]. If thepatient is compliant with footwear use, the stresses meas-ured using in-shoe techniques reflect the influence of ana-tomical structure, lower extremity function, lifestyle, andfootwear construction.Finite element modelling of the foot, and in some casesfootwear, has been explored by a number of groups [10-12] to provide estimates of quantities that cannot bedirectly measured or to perform simulations that wouldbe onerous or dangerous for human subjects. Our ownrecent work has been directed towards the development ofmore realistic soft tissue models utilizing detailed defor-mation measurements of foot structures [13] and anattempt to reduce the burden of mesh development by theuse of morphing techniques to modify stock meshes.

Charcot Pathogenesis: A Study of In Vivo Gene Expression

BACKGROUND Total-contact casting is an effective method to treat various pathologic abnormalities in patients with diabetic neuropathy, but its use is frequently associated with iatrogenic complications. METHODS The largest retrospective review to date of iatrogenic complications of total-contact casts was conducted over an 8-year period at Cleveland Clinic. RESULTS In the past 8 years, 23% of patients developed complications, and the most common complication was a new heel ulcer formation. Of these complications, 92.1% resolved, 6.4% were lost to follow-up, and 1.4% resulted in a partial foot amputation. Mean cast duration was 10.3 days for patients who developed a total-contact cast iatrogenic complication. The most common indication for the use of a total-contact cast was a neuropathic foot ulceration. CONCLUSIONS The results of this study support the use of total-contact casting in the insensate patient with diabetes. However, adequate staff training in total-contact cast application is recommended to reduce complications.