Biomedical subjects

L A Lavery

Publications and source records attributed to L A Lavery.

At least 37 records · Page 2Linked to original sources

PubMed1998

Validation of a diabetic wound classification system. The contribution of depth, infection, and ischemia to risk of amputation.

OBJECTIVE: To validate a wound classification instrument that includes assessment of depth, infection, and ischemia based on the eventual outcome of the wound. RESEARCH DESIGN AND METHODS: We evaluated the medical records of 360 diabetic patients presenting for care of foot wounds at a multidisciplinary tertiary care foot clinic. As per protocol, all patients had a standardized evaluation to assess wound depth, sensory neuropathy, vascular insufficiency, and infection. Patients were assessed at 6 months after their initial evaluation to see whether an amputation had been performed. RESULTS: There was a significant overall trend toward increased prevalence of amputations as wounds increased in both depth (chi 2trend = 143.1, P < 0.001) and stage (chi 2trend = 91.0, P < 0.001). This was true for every subcategory as well with the exception of noninfected, nonischemic ulcers. There were no amputations performed within this stage during the follow-up period. Patients were more than 11 times more likely to receive a midfoot or higher level amputation if their wound probed to bone (18.3 vs. 2.0%, P < 0.001, chi 2 = 31.5, odds ratio (OR) = 11.1, CI = 4.0-30.3). Patients with infection and ischemia were nearly 90 times more likely to receive a midfoot or higher amputation compared with patients in less advanced wound stages (76.5 vs. 3.5%, P < 0.001, chi 2 = 133.5, OR = 89.6, CI = 25-316). CONCLUSIONS: Outcomes deteriorated with increasing grade and stage of wounds when measured using the University of Texas Wound Classification System.

Adult↗

PubMed1998

1998 William J. Stickel Silver Award. Mechanically assisted, delayed primary closure of diabetic foot wounds.

The authors evaluated the time to healing and prevalence of complications in patients undergoing mechanically assisted, delayed primary closure of diabetic foot wounds compared with a similar population who received standard wound care. A total of 55 patients were enrolled for study, with 25 in the experimental group and 30 in the control group. Patients in the experimental (stretch) group underwent mechanically assisted primary closure of their wounds using a skin-stretching device. There was no difference between the stretch and control groups with regard to any descriptive characteristics, including wound chronicity. Although the wounds were over three times as large on average in the stretch group (P < .001), the stretch group reached full epithelialization approximately 40% sooner than the control group (26.4 +/- 16.0 versus 42.5 +/- 19.9 days; P < .002). Eighty-eight percent of patients in the stretch group experienced wound dehiscence, at a mean time of 1.8 +/- 0.6 weeks following mechanically assisted closure. However, patients who experienced dehiscence in the stretch group healed significantly faster than patients in the control group (27.4 +/- 16.7 versus 42.5 +/- 19.9 days; P < .007). The results of this study suggest that mechanically assisted closure of diabetic foot wounds may result in reduced healing time compared with healing by secondary intention.

Adult↗

PubMed1998

Who is at risk for diabetic foot ulceration?

Diabetic foot ulceration is the most common cause of nontraumatic, lower-extremity amputation throughout the developed world. This article reviews recent data that report on various risk factors for ulceration. Subsequently, it discusses appropriate risk stratification for both the neuropathic ulcer specifically and the diabetic foot in general, using The University of Texas Diabetic Foot and Diabetic Wound Classification Systems. We believe that knowledge and communication of the most common risk factors precipitating ulceration and subsequent amputation lead to more consistent treatment of the diabetic foot, and, ultimately, to a reduction of its prevalence.

Diabetic Foot↗

PubMed1998

Evidence-based options for off-loading diabetic wounds.

Whereas the treatment of the diabetic wound has received a great deal of attention in the medical literature, the majority of the focus of recent research has been centered on dressings and advanced wound healing modalities. All these methods, however, are less than effective if the central tenet of treating the diabetic wound, namely reducing plantar pressure through off-loading, is not addressed primarily. This article examines the most commonly used off-loading methods in the medical literature and discusses the attributes and disadvantages of many of these devices.

Casts, Surgical↗

PubMed1998

Reaching closure with skin stretching. Applications in the diabetic foot.

At the present time, there are no evidence-based protocols outlining the use of the Sure-Closure Skin Stretching System on diabetic, neuropathic wounds. Ideally, surgical correction of the precipitating deformity and appropriate shoe gear accommodation should be performed con-comitantly with skin stretching (as indicated) to achieve an optimal long-term result. For several years, we have used the Sure-Closure device as an adjunctive treatment for diabetic-foot wound closure, and believe that, ultimately, this device more likely will be used in a clinical setting. In this manner, a patient with an open wound may, under aseptic conditions, be sequestered for a period of 1 to 2 hours during a clinical visit to allow for skin stretching. This procedure may be carried out two or three times weekly until closure is achieved. Mechanically assisted delayed primary closure is a relatively new category of wound closure; however, this device is by no means a panacea. Appropriate patient selection and intraoperative judgment are of critical preoperative and perioperative importance when employing this technique. Currently, we are completing a clinical trial comparing mechanically assisted delayed primary-wound closure to traditional treatment and off-loading in a population of high-risk diabetic patients. We believe that this project will better elucidate the relative indications and contraindications with what may be a very effective tool for the diabetic foot specialist.

Dermatologic Surgical Procedures↗

PubMed1998

How effective is manual palpation in detecting subtle temperature differences?

In the management of diabetic, neuropathic sequelae, namely ulceration and Charcot's arthropathy, appropriate quantification of inflammation is critically important in predicting future events and charting current progress. This article evaluates the ability of the physician to quantify subtle differences in temperature through manual palpation. The "laying on of hands" in a clinical setting is a necessary, crucial component of the doctor-patient relationship; however, our data suggest that manual palpation, even in a controlled environment, may not be an objective means to assess temperature, a cardinal sign of inflammation.

Adult↗

PubMed1998

Peak foot pressures influence the healing time of diabetic foot ulcers treated with total contact casts.

The purpose of this article is to describe the progression of ulcer healing using total contact casts (TCC) and to examine explanatory variables that may influence ulcer healing. We prospectively studied 25 diabetics with grade I (Meggitt-Wagner) plantar ulcers. All subjects received weekly contact cast changes with wound assessment. Following healing, all subjects were fitted with prescription shoe gear. Mean duration of casting until healing was 38.8 +/- 21.3 days. Individuals with pressures over 99 N/cm2 took longer to heal (33.1 +/- 13.0 vs. 53.4 +/- 31.4 days, P = 0.05) and had longer ulcer duration prior to treatment (52.7 +/- 37.2 vs. 180.7 +/- 145.0 days, P = 0.02). Subjects with wound size greater than 8 cm2 took longer to heal (50.2 +/- 26.2 vs. 29.9 +/- 10.6 days, P = 0.02). We conclude that subjects with high plantar pressures and wounds greater than 8 cm2 took significantly longer to heal when uniformly treated with TCC.

Adult↗

PubMed1998

Is postural instability exacerbated by off-loading devices in high risk diabetics with foot ulcers?

Pressure reduction is of pivotal importance in any treatment plan designed to heal diabetic foot ulcers. However, to our knowledge, no work has evaluated the effect of ambulatory pressure reducing devices on postural stability (PS) in high risk diabetics. Therefore, the purpose of this study was to compare PS associated with 5 off-loading strategies: total contact casts with cast boot, total contact casts with heel, removable cast walker, half-shoes, and canvas shoes using a repeat measure design. Twenty-six diabetic patients with foot ulcers were enrolled in the study. Using a digital pressure platform, the degree of sway was measured as total deviation of center of force. Three 30 second trials were evaluated using Turkey's studentized range test for multiple comparisons (alpha = 0.05). Sway was significantly greater with total contact casts with heel compared to other devices. While total contact casting remains the gold standard with which to treat neuropathic ulcers, care should be taken when placing patients in any devices that may exacerbate postural instability. The results suggest that total contact casts with an incorporated rubber heel may indeed accentuate sway. It is therefore recommended that the rubber heel be eliminated in lieu of a protective cast boot when using this modality.

Adult↗

PubMed1998

Biomechanical topography of human articular cartilage in the first metatarsophalangeal joint.

The objective of this study was to provide a map of cartilage biomechanical properties, thickness, and histomorphometric characteristics in the human, cadaveric first metatarsophangeal joint, to determine if normal articular cartilage was predisposed topographically to biomechanical mismatches in articulating surfaces. Cartilage intrinsic material properties and thickness were obtained from seven pairs of human, freshly frozen, cadaveric, metatarsophalangeal joints using an automated creep indentation apparatus under conditions of biphasic creep. Eight sites were tested: four on the metatarsal head, two on the proximal phalanx base, and one on each sesamoid bone to obtain the aggregate modulus, Poisson's ratio, permeability, shear modulus, and thickness. Cartilage in the lateral phalanx site of the left metatarsal head had the largest aggregate modulus (1.34 MPa), whereas the softest tissue was found in the right medial sesamoid (0.63 MPa). The medial phalanx region of the right joint was the most permeable (4.56 x 10(-15) meter4/Newton-second), whereas the medial sesamoid articulation of the metatarsal head of the left joint was the least permeable (1.26 x 10(-15) meter4/Newton-second). Material properties and thickness are indicative of the tissue's functional environment. The lack of mismatches in cartilage biomechanical properties of the articulating surfaces found in this study may be supportive of clinical observations that early degenerative changes, in the absence of traumatic events, do not occur at the selected test sites in the human first metatarsophalangeal joint.

Adolescent↗

PubMed1998

Plantar pressures are higher in diabetic patients following partial foot amputation.

The purpose of this study was to compare peak plantar pressure in diabetic patients with and without foot-level amputation. This project was conducted as a case-control study. We enrolled 27 cases and 150 controls diagnosed with diabetes mellitus. Cases were defined as patients with a history of forefoot-level amputation (digit or ray amputations distal to the tarsometatarsal joint) secondary to an infected forefoot wound. Controls were defined as subjects that had never had a foot ulceration. We used a pressure platform system to evaluate dynamic barefoot pressure on the sole of the foot. There was no significant difference in vascular perfusion or body mass index between the case and control groups. Patients with a foot-level amputation were nearly ten times more likely to present with limited joint mobility or a rigid foot deformity than those without amputation (92.6% vs. 44.0%, p < 0.0001, X2 = 13.0, Odds Ratio = 9.8 CI = 2.2 to 43.0). Peak plantar pressure was significantly higher for patients with amputations compared to controls (80.0 +/- 31.1 N/cm2, vs, 62.5 +/- 21.0 N/cm2, p < 0.001). Peak pressure and limited joint mobility have long been associated with ulceration. We conclude that increased pressure and contractures associated with biomechanical compensation following a partial foot amputation further increase plantar pressure, placing an already high-risk limb at further risk for tissue breakdown and reamputation.

Adult↗

PubMed1998

Vibration perception threshold: are multiple sites of testing superior to single site testing on diabetic foot examination?

Vibration perception threshold (VPT) values, measured at different anatomic locations on the foot and ankle, and the time to assess VPT and sensory perception using two difference modalities in 102 diabetic patients were compared. VPT was evaluated at the great toe, fifth metatarsal and ankle. Differences in VPT at these three sites, in addition to differences in duration of testing comparing single site (great toe) to multiple sites, and to standard SWMF testing were assessed. No significant difference in VPT between the great toe and fifth metatarsal was found for patients both with and without loss of protective sensation (LOPS). Mean VPT was significantly higher at the ankle compared with both the great toes and fifth metatarsals. However, the difference between ankle and great toe was not significant between patients with and without LOPS [3.9 +/- 11.2 (12%) vs. 3.0 +/- 10.8 (16%) volts, respectively, p > 0.6]. Testing of one site took approximately half the time of Semmes-Weinstein 10-gram monofilament wire SWMF testing (40.5 +/- 16.9 vs. 22.3 +/- 9.1 seconds, p < 0.01) and less than one third the time of three-site VPT testing (10.5 +/- 26.1 vs. 22.3 +/- 9.1 seconds, p < 0.01). There may not be a significant practical benefit in multiple site VPT testing when compared with single site testing on the great toe alone. The value of multiple site testing is further called into question when one notes that the great toe VPT remains the only site tested for sensitivity and specificity for ulceration.

Diabetic Foot↗

PubMed1997

Healing rates of diabetic foot ulcers associated with midfoot fracture due to Charcot's arthropathy.

The aim of this study is to compare the effectiveness of total contact casts based on wound location in groups of patients with diabetes mellitus with neuropathic ulcerations under the forefoot and patients with midfoot ulcerations associated with acute Charcot's arthropathy. Twenty-five consecutive diabetic patients with Meggitt-Wagner grade I neuropathic foot ulceration (NU) and 22 consecutive diabetic patients with neuropathic ulceration and acute Charcot's arthropathy (CU) were selected for study. Larger wounds took longer to heal in both the CU (p < 0.0001) and NU groups (p < 0.0001). Duration of ulcer prior to treatment also was significantly associated with increased healing time in both groups (p = 0.008 NU, p = 0.03 CU). The CU group had larger wounds (10.3 +/- 4.6 vs 7.7 +/- 4.0 cm2, p = 0.04) but took significantly less time to heal (28.4 +/- 13.0 vs 38.8 +/- 21.3 days, p = 0.04) than did subjects with neuropathic ulcerations only. The NU group had their ulcers present for a significantly longer period of time prior to contact casting (88.5 +/- 98.3 vs 17.7 +/- 12.9 days, p = 0.001). In this study, subjects with ulcerations secondary to acute Charcot fractures healed more rapidly than in previous reports with healing times of forefoot neuropathic ulcers similar to previous studies. Every patient's ulcer healed. There were no cast-related ulcerations, infections, or hospitalizations. Concerns regarding the safety of total contact casts to treat well-vascularized superficial forefoot and midfoot plantar wounds appear to be unfounded.

Adult↗

PubMed1997

The natural history of acute Charcot's arthropathy in a diabetic foot specialty clinic.

The aim of this longitudinal study was to report on the clinical characteristics and treatment course of acute Charcot's arthropathy at a tertiary care diabetic foot clinic. Fifty-five diabetic subjects, with a mean age of 58.6 +/- 8.5 years, were studied. All patients were treated with serial total contact casting until quiescence. Following casting and before transfer to prescription footwear, patients were eased into unprotected weightbearing via a removable cast walker. This cohort was followed for their entire treatment course and for a mean 92.6 +/- 33.7 weeks following return to shoes. Pain was the most frequent presenting complaint in these otherwise insensate patients (76%). The mean duration of casting was 18.5 +/- 10.6 weeks. Patients returned to footwear in a mean 28.3 +/- 14.5 weeks. Nine per cent of the population had bilateral arthropathy. These subjects were casted significantly longer than the unilateral group (p < 0.02). Surgery was performed on 25 % of patients, with approximately two-thirds of these procedures involving plantar exostectomies and one-third fusions of affected joints. Patients receiving surgery remained casted significantly longer than non-surgical patients (p < 0.05). Additionally, men were casted longer than women (p < 0.008). Acute Charcot's arthropathy requires prompt, uncompromising reduction in weightbearing stress. Our data show that the ambulatory total contact cast is very effective for this. Regardless of the specific treatment method instituted, it is imperative that appropriate and aggressive treatment be undertaken immediately following diagnosis to help prevent progression to a profoundly debilitating, limb-threatening deformity.

Acute Disease↗

PubMed1997

Institutionalization following diabetes-related lower extremity amputation.

PURPOSE: We are unaware of any report in the medical literature that has discussed risk factors for both mortality and discharge disposition following lower extremity amputation (LEA). Our aim was to report risk factors associated with in-hospital mortality and the need for institutional care in diabetics with LEAs. PATIENTS AND METHODS: We abstracted data for every hospitalization for a LEA from January 1 to December 31, 1993 in six metropolitan statistical areas in South Texas. Amputation level was categorized as foot, leg, or thigh. Discharge status categories were: home, nursing home, rehabilitation facility, and death. We used the Kaplan scale of cogent comorbidities to determine the relationship of 12 disease categories and their association with discharge status. RESULTS: There were 1,043 LEAs in South Texas in 1993. Although only 2.3% of the population was admitted from an institutional care facility, over 25% were discharged to one. Of the total population, 18.5% were discharged to a nursing home and 7.0% to a rehabilitation facility, and 5.1% died within the period of hospitalization. We performed a univariate analysis. Factors with a P <0.25 were included in a stepwise logistic regression analysis with an alpha of 0.05. High level (leg or thigh) amputation, peripheral vascular disease, male gender, and absence of advanced locomotor impairment were associated with discharge to a rehabilitation facility. For discharge to a nursing home, significant associations were found with: female gender, advanced age (>65 years), single marital status, high level amputation, and advanced cerebrovascular disease and locomotor impairment. Death following LEA was strongly associated with female gender, high level amputation, advanced renal disease, anemia, and congestive heart failure. CONCLUSION: A significant number of patients either die or require long-term care following a diabetes-related LEA, thus further adding to the burden of this sequela. Several clinical parameters are significantly associated with discharge status after this procedure. More prospective clinical research is needed to verify the associations and to clarify their application in practice.

Aged↗

PubMed1997

Gait pattern alteration by functional sensory substitution in healthy subjects and in diabetic subjects with peripheral neuropathy.

OBJECTIVE: To evaluate the ability of diabetic and nondiabetic individuals to learn to use a lower extremity sensory substitution device to cue gait pattern changes. DESIGN: Case-control study. SETTING: Gait laboratory. PARTICIPANTS: Thirty diabetic persons and 20 age- and education-matched nondiabetic controls responded to advertisements for study participation. INTERVENTION: Participants walked on a treadmill at three speeds (1, 2, and 2.5mph) with auditory sensory feedback to cue ground contact greater than 80% duration of baseline. MAIN OUTCOME MEASUREMENTS: The variables measured included gait cycle (steps per minute) and number of times per minute that any step during a trial exceeded 80% duration of ground contacted compared with a measured baseline step length for each speed. RESULTS: Persons in both groups were able to rapidly and significantly alter their gait patterns in response to signals from the sensory substitution device, by changing their gait cycles (nondiabetic group, F(17,124) = 5.27, p < .001; diabetic group, F(5,172) = 3.45, p < .001). Post hoc analyses showed early gait cycle modification and error reduction among both groups. The nondiabetic group learned to use the device significantly more quickly than the diabetic group during the slow (1mph, t = 3.57, p < .001) and average (2mph, t = 2.97, p < .05) trials. By the fast (2.5mph) ambulation trial, both groups were performing equally, suggesting a rapid rate of adjustment to the device. No technical failures from gait trainer malfunction occurred during the study. CONCLUSIONS: Diabetic persons with neuropathy effectively used lower extremity sensory substitution, and the technology is now available to manufacture a durable, effective lower extremity sensory substitution system.

Adult↗

PubMed1997

Total contact casts: pressure reduction at ulcer sites and the effect on the contralateral foot.

OBJECTIVE: To compare the effectiveness of total contact casts with a cast boot (TCCB), total contact casts with a cast heel (TCCH), and therapeutic XtraDepth shoes (XDS) to reduce ulcer site pressures and to determine if total contact casts increase contralateral pressures. DESIGN: Repeat measure design with 40 replications nested within each treatment for each patient. METHODS: Peak contralateral foot pressures and ulcer site pressures under the 1st metatarsal (1MET; n = 10), 2nd to 5th metatarsals (2-5MET; n = 10), and great toe (GT; n = 5) were compared using the Novel-Pedar system and three treatments: TCCB, TCCH, and XDS. Baseline pressures were established using canvas oxfords. RESULTS: There was no difference in pressure reduction with TCCH vs. TCCB for 1MET or GT ulcers, but TCCH reduced pressure better for 2-5MET ulcers (p < .001). Contralateral pressures were not elevated in either TCC group. CONCLUSIONS: TCCH were superior to TCCB in reducing 2-5MET ulcer pressures and equivalent to TCCB for 1MET and GT ulcers. Contralateral pressures are not increased by TCC use.

Adult↗

PubMed1997

Mortality following lower extremity amputation in minorities with diabetes mellitus.

The aim of this study was to identify the age adjusted and level specific mortality rate in African-Americans, Hispanics and non-Hispanic whites (NHW) during the perioperative period following a lower extremity amputation. We identified amputation data obtained from the Office of Statewide Planning and Development in California for 1991 from ICD-9-CM codes 84.11-84.18 and diabetes mellitus from any 250 related code. Amputations were categorized as foot (84.11-84.12), leg (84.13-84.16) or thigh (84.17-84.18). Death was coded under discharge status. Age adjusted and level specific mortality rates per 1000 amputees were calculated for each race/ethnic group. The age adjusted mortality was highest for African-Americans (41.39) compared to Hispanics (19.69) and NHW's (34.98). Mortality was consistently more frequent for proximal amputations. We conclude that mortality rates for persons with diabetes hospitalized for an amputation varied by race, gender and level of amputation. Higher prevalence or severity of risk factors may explain the excess mortality observed in African-Americans.

Adult↗

PubMed1997

Methodological issues affect variability in reported incidence of lower extremity amputations due to diabetes.

The aim of this study is to evaluate the influence of different methodological techniques commonly utilized to identify the incidence of diabetes related lower extremity amputations. Medical records for each hospitalization for an amputation in 1993 in six metropolitan statistical areas in South Texas were abstracted. Every hospitalization, amputation and amputee was identified to allow separate analysis. Furthermore, data was categorized by ethnicity, level and age. Diabetes was verified using WHO criteria. Incidence rates were calculated per 10,000 diabetic patients at risk per year, both diagnosed only (DO) and diagnosed and undiagnosed combined (DUC). In total 1922 amputations were carried out during 1228 hospitalizations for 1043 amputees. The incidence rates per 10,000 diabetic patients (DO) were: 157.6 amputations, 101.2 hospitalizations and 87.0 amputees. When calculated using the DUC population at risk the rates were: 92.8 amputations, 59.6 hospitalizations and 51.2 amputees. Trends were found to be similar when analyzed by gender and ethnicity. The variability detected using of different methodological techniques to determine incidence rates is considerable and may have significant consequences when rates from different studies are compared.

Adult↗