Experimental testing of a prototype cantilevered liquid-nitrogen-cooled silicon mirror.

This report presents testing of a prototype cantilevered liquid-nitrogen-cooled silicon mirror. This mirror was designed to be the first mirror for the new soft X-ray beamlines to be built as part of the Advanced Light Source Upgrade. Test activities focused on fracture, heat transfer, modal response and distortion, and indicated that the mirror functions as intended.

A role for TNF in bone resorption of deciduous molars in human beings.

In this study, tumor necrosis-alpha was sampled from the gingival crevice of human deciduous molars; this was compared with values measured from the crevice of those deciduous molars missing a permanent successor, and from the crevice of deciduous ankylosed molars. Tumor necrosis-alpha was harvested from the gingival crevice with magnetic microspheres coated with tumor necrosis-alpha antibodies. The amount of bead-bound tumor necrosis-alpha was quantified with the use of an enzyme-linked immunosorbent assay. One hundred seven sites (from 41 patients) were sampled; for each patient, the normal value was compared with either the molars missing a permanent successor or ankylosed value. The tumor necrosis-alpha levels were 1.6 times higher from the crevice of ankylosed deciduous molars when compared with normal deciduous molars and 2.6 times higher from the crevice of sites with a molar missing a permanent successor. The mean and standard error mean distribution of tumor necrosis-alpha expressed as picograms was: normal molars 91 pg (standard error mean +/- 20), ankylosed molars 150 pg (standard error mean +/- 31), and missing permanent successor 236 pg (standard error mean +/- 67). Analysis of variance showed the difference among the 3 means was close to attaining significant difference (F [2.104] = 2.7905, P =.066). Multiple comparison procedures indicated that the mean for molars missing a permanent successor and the normal groups were significantly different, P =.05. The results of this study suggest tumor necrosis-alpha values are elevated in the gingival crevice of deciduous molars with ankylosis and where the permanent tooth bud is congenitally missing.

Evaluation of a collagen-alginate wound dressing in the management of diabetic foot ulcers.

Efficacy and safety of a collagen-alginate topical wound dressing (FIBRACOL Collagen-Alginate Wound Dressing) in the treatment of diabetic foot ulcers was compared with that of regular gauze moistened with normal saline. Seventy-five patients with foot ulcers were assigned randomly in a 2:1 ratio to the collagen-alginate test dressing or the gauze dressing. At the end of the study, the mean percent reduction of the wound area was 80.6% +/- 6% in the collagen-alginate dressing group and 61.1% +/- 26% in the gauze dressing group (p = .4692). Thirty-nine (78%) patients treated with the collagen-alginate dressing achieved > or = 75% wound area reduction, compared with 15 (60%) of gauze-treated patients. Complete healing was achieved in 24 (48%) of the collagen-alginate dressing group and 9 (36%) of the gauze dressing group. Wound size, when averaged over the 8-week period and with the duration of the ulcer taken into account, was reduced significantly in the collagen-alginate dressing group, as compared with the gauze dressing group (df = 1, p = .0049). It is concluded that the collagen-alginate test dressing is as or more effective and safe as the currently used treatment.

Endothelial dysfunction and the expression of endothelial nitric oxide synthetase in diabetic neuropathy, vascular disease, and foot ulceration.

We studied endothelial-mediated microvascular blood flow in neuropathic diabetic patients to determine the association between endothelial regulation of the microcirculation and the expression of endothelial constitutive nitric oxide synthetase (ecNOS) in the skin. Vasodilation on the dorsal foot in response to heating and iontophoresis of acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) were measured using single-point laser Doppler and laser Doppler imaging in diabetic patients with neuropathy (DN), with neuropathy and vascular disease (DI), with Charcot arthropathy (DA), and without complications (D), and in healthy control subjects (C). The response to heat was reduced in the DN (321 [21-629] percentage of increase over the baseline, median [interquartile range]) and DI (225 [122-470]) groups but was preserved in the DA (895 [359-1,229]), D (699 [466-1,029]), and C (810 [440-1,064], P < 0.0001) groups. The endothelial-mediated response to acetylcholine was reduced in the DN (17 [11-25]), DA (22 [2-34]), and DI (13 [2-30]) groups compared with the D (47 [24-58]) and C (44 [31-70], P < 0.001) groups. The non-endothelial-mediated response to sodium nitroprusside was also reduced in the DI (4 [0-18]), DN (17 [9-26]), and DA (21 [11-31]) groups compared with the D (37 [19-41]) and C (44 [26-67], P < 0.0001) groups. There was a significant reduction in vasodilation in the DI group compared with all other groups (P < 0.0001). Full thickness skin biopsies from the dorsum of the foot of 15 DN, 10 DI, and 11 C study subjects were immunostained with antiserum to human ecNOS, the functional endothelial marker GLUT1, and the anatomical endothelial marker von Willebrand factor. The staining intensity of ecNOS was reduced in both diabetic groups. No differences were found among the three groups in the staining intensity of von Willebrand factor and GLUT1. We conclude that the endothelium-dependent and endothelium-independent vasodilations are impaired in diabetic patients predisposed to foot ulceration and that neuropathy is the main factor associated with this abnormality. Reduced expression of ecNOS may be a major contributing factor for endothelial dysfunction. These data provide support for a close association of neuropathy and microcirculation in the pathogenesis of foot ulceration.

Neuropathic ulcerations plantar to the lateral column in patients with Charcot foot deformity: a flexible approach to limb salvage.

Neuroarthropathy of the midfoot may lead to a structural deformity that predisposes the diabetic patient to skin breakdown and ulceration. In some cases, conservative management is not adequate, making surgical intervention necessary. The authors performed a retrospective study to look at those patients who required surgical intervention for a specific pattern of neuroarthropathy. Over a 2 1/2-year period, 32 feet (31 patients) underwent surgical procedures for treatment of nonhealing neuropathic ulcerations beneath the lateral column of Charcot feet. All feet underwent exostectomy with 17 undergoing excision of the ulcer with primary closure, 8 closure via rotational fasciocutaneous flap with transpositional intrinsic muscle flap, and 6 through an incision placed adjacent to the ulcer. One patient whose ulcer was healed at the time of surgery had the incision placed directly over the prominence. Overall, 29 of 32 feet maintained functional limb salvage. This included eight patients who required revisional surgery, either by resection of more bone or creation of a local flap for coverage. Life-table analysis resulted in an 89% overall success rate. The results show that a flexible approach to skin and soft tissue coverage is necessary to heal these patients, provided attention is directed to the underlying bony prominence.

Longitudinal in-shoe foot pressure relief achieved by specially designed footwear in high risk diabetic patients.

Specially designed Thor-Lo footwear has been shown to reduce the in-shoe foot pressures in diabetic patients at risk of foot ulceration when compared to their own footwear. Fifty at high risk patients 32 (64%) males, 17 (34%) type 1 diabetes) have been provided with this foot wear and have been followed up for 6 months. Mean age was 57.6 (range, 34-78) years, duration of diabetes 22.4 (range, 4-50) years, Neuropathy Symptom Score 3.36 +/- 2.96 (mean +/- S.D.), Neuropathy Disability Score 16.8 +/- 6.83, VPT 43.4 +/- 11.8 Volts while 43 (86%) could not feel a 5.07 or smaller Semmes-Weinstein monofilament. Forty-two (84%) patients were re-examined at an interim visit 3 months after baseline, while 37 (74%) completed the study. In-shoe peak forces and pressures were measured using the F-Scan system. No difference was found among the peak force among baseline (95.5 +/- 26 kg), interim (96.5 +/- 33) and final visit (97.7 +/- 25.2, P + NS). There was no difference in peak pressures at the baseline (3.98 +/- 1.42 kg.cm-2), second visit (4.13 +/- 2.30) and the final visit (4.25 +/- 1.51). Nine (18%) patients developed foot problems and one died during the study. We conclude that no changes in foot pressures were found over a period of 6 months of continuous usage of the specially designed footwear in a group of diabetic patients at risk of foot ulceration. Further prospective studies are required to evaluate the impact of specially designed footwear in reducing the rate of foot ulceration.

Differences in joint mobility and foot pressures between black and white diabetic patients.

Limited joint mobility is common in diabetes and is related to high foot pressures and foot ulceration. We have examined the differences in joint mobility and foot pressures in four groups matched for age, sex, and duration of diabetes: 31 white diabetic, 33 white non-diabetic, 24 black diabetic, and 22 non-diabetic black subjects. Joint mobility was assessed using a goniometer at the fifth metacarpal, first metatarsal, and subtalar joints. In-shoe and without shoes foot pressures were measured using an F-Scan system. Neuropathy was evaluated using clinical symptoms (Neuropathy Symptom Score), signs (Neuropathy Disability Score), and Vibration Perception Threshold. There was no difference between white and black diabetic patients in Neuropathy Symptom Score, Neuropathy Disability Score, and Vibration Perception Threshold. Subtalar joint mobility was significantly reduced in white diabetic patients (22 +/- 7 degrees) compared to white controls (26 +/- 4 degrees, black diabetic patients (25 +/- 5 degrees), and black controls (29 +/- 7 degrees), and increased in black controls compared to white controls and black diabetic patients (level of statistical significance p < 0.05). Without shoes foot pressures were higher in white diabetic patients (8.31 +/- 400 kg cm-2) compared to white controls (6.81 +/- 2.31 kg cma2), black diabetic patients (6.2 +/- 2.53 kg cm-2) and black controls (5.00 +/- 1.24 kg cm-2) and lower in black controls compared to white and black diabetic patients (p < 0.05 in all cases). We conclude that racial differences exist in joint mobility and foot pressures between black and white subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Preventing loss of the great toe with the hallux interphalangeal joint arthroplasty.

Chronic ulcerations of the hallux may result in amputation if infection becomes uncontrolled. Salvage of the hallux often requires surgical intervention when conservative measures fail. Many authors have described various procedures to prevent recurrent ulceration and the potential for loss of the great toe. The authors have reviewed their experience with the hallux interphalangeal joint arthroplasty for chronic neuropathic ulcers of the great toe. Between August 1988 and July 1991, the authors performed 46 hallux interphalangeal joint arthroplasties on 40 patients (22 males, 18 females). Of the 40 original patients, one patient was lost to follow-up in the immediate postoperative period, leaving 45 procedures on 39 patients. Thirty-six feet were noted to heal both the procedure and ulceration uneventfully (80%). There were five minor complications (11%). Four cases were deemed failures (9%). Overall, 41 feet (91%) healed and had no evidence of recurrence in the follow-up period. Follow-up was an average of 23.6 months (range 4-44 months). The hallux interphalangeal joint arthroplasty has been a valuable procedure for chronic ulcerations of the hallux. By allowing these ulcers to heal, loss of the great toe has been avoided. Function and structure of the foot has been maintained.

In-shoe foot pressure measurements in diabetic patients with at-risk feet and in healthy subjects.

OBJECTIVE: To measure in-shoe foot pressures in diabetic patients and healthy subjects and compare them with the foot pressures when they walked without their shoes. RESEARCH DESIGN AND METHODS: Forty-four diabetic patients at risk of foot ulceration and 65 healthy subjects were matched for age, sex, race, and weight. Neuropathy was evaluated clinically, and the F-Scan program was used to measure the foot pressures. Foot pressures were measured with the sensors placed in the shoes (S measurements), between the foot and the sock with shoes (H measurements) or with their socks alone (B measurements). RESULTS: In the control group, significant differences were found between S (4.77 +/- 1.87 kg/cm2) and H measurements (5.12 +/- 1.87 kg/cm2, P < 0.001), between S and B (7.23 +/- 2.95 kg/cm2, P < 0.0001), and between H and B (P < 0.0001). In the diabetic group, no difference was found between S and H measurements (5.28 +/- 2.22 vs. 5.27 +/- 2.39 kg/cm2, NS). In contrast, the B pressure was significantly higher when compared with both (8.77 +/- 4.67 kg/cm2, P < 0.02). When compared with the control group, the S and H pressures did not differ significantly, but the B pressure in the diabetic group was significantly higher (P < 0.02). The peak S pressure was above the normal limit in 24 (27%) diabetic and 21 (16%) control feet (P < 0.05), the H pressure in 17 (19%) diabetic feet and 22 (17%) control feet (NS), and the B pressure in 24 (27%) diabetic and 21 (16%) control feet (P < 0.05). CONCLUSIONS: In-shoe foot pressure measurements are significantly lower than the ones measured when walking with the socks only in both diabetic patients and healthy subjects. The shoes of diabetic patients provided a higher pressure reduction than did those of the control group, but the number of feet with abnormally high pressures did not change. The F-Scan system may be particularly helpful in designing footwear suitable for diabetic patients with at-risk feet.

Maximizing foot salvage by a combined approach to foot ischemia and neuropathic ulceration in patients with diabetes. A 5-year experience.

OBJECTIVE: The combination of peripheral neuropathy and arterial insufficiency in patients with diabetes frequently results in chronic non-healing foot ulcers. These patients often have a protracted course that commonly ends in limb amputation. RESEARCH DESIGN AND METHODS: Since 1987, 39 diabetic patients presented with 42 neuropathic ulcerations beneath the lesser metatarsal heads, complicated by severe arterial insufficiency. A variety of vascular reconstructions were performed to improve circulation to the foot. After successful vascular reconstruction, 14 patients with deep ulcers underwent resection of the involved bone or joint through a plantar elliptical incision with excision of the ulcer and primary closure (33%). Five patients required a simultaneous panmetatarsal head resection (12%). For fifteen superficial ulcers, metatarsal osteotomy through a dorsal approach was performed (36%). Eight patients underwent a fifth metatarsal head resection through a dorsal approach (19%). RESULTS: In follow-up of 2-64 months (mean 21.2 months), 35 extremities with patent bypass grafts achieved and maintained primary healing of their local foot procedure (83%). Two feet required subsequent revision but ultimately healed (5%). Three feet (7%) developed a new plantar ulceration adjacent to the original one. In two extremities, the foot remained healed in spite of thrombosis of their grafts (5%). One patient with a thrombosed graft required a below-knee amputation. One patient died before the foot healed with a patent bypass graft. Overall, 40 of 42 extremities (95%) ultimately healed over the course of the follow-up period. CONCLUSIONS: We conclude that complex neuropathic ulcers in diabetic patients can be successfully treated by an aggressive surgical approach that removes infected bone and ulcers and corrects underlying structural abnormalities provided arterial insufficiency is corrected first.

Panmetatarsal head resection. A viable alternative to the transmetatarsal amputation.

While the transmetatarsal amputation has resulted in the salvage of numerous diabetic limbs, it remains an ablative procedure with both short- and long-term complications. The authors reviewed their experience with the panmetatarsal head resection as an alternative to the transmetatarsal amputation. A retrospective review was performed of all patients having undergone this procedure between May 1986 and November 1991. Thirty-seven procedures were performed; of these, 34 were evaluated. The average follow-up period was 20.9 months. Thirty-two feet showed primary healing while one showed delayed healing. One patient had local recurrence of the original ulceration. Primary healing was 94% while overall success was 97%. No patient required amputation of any kind. The authors conclude that the panmetatarsal head resection is a viable alternative to the transmetatarsal amputation in properly selected patients because it avoids many of the structural and biomechanical pitfalls of the transmetatarsal amputation.

A biomechanical model for the transmetatarsal amputation.

The transmetatarsal amputation has been performed for over 40 years as a limb salvage procedure, in diabetic patients with nonhealing ulcerations or nonreconstructible ischemia. It is generally believed that the transmetatarsal amputation provides a better walking extremity than a more proximal amputation and is more energy efficient. A review of the literature reveals little regarding the biomechanics of the "short foot." The authors will review the functions of the myofascial structures in both the normal foot and the transmetatarsal amputation and discuss the influence of mechanics on transmetatarsal amputation lesions.

Tendo Achillis procedures for chronic ulcerations in diabetic patients with transmetatarsal amputations.

Recurrent ulceration following transmetatarsal amputation commonly results from hypertrophic bone formation or equinus deformity. In the current study, 31 diabetic patients underwent 33 Achilles tendon procedures for recurrent ulcerations at the distal stump of their transmetatarsal amputation. Primary healing was achieved in 21 procedures (64%) and secondary healing in 9 procedures (27%) for an overall healing rate of 91%. Two procedures failed to resolve the original ulceration (6%). The average follow-up examination was 27 months. The authors conclude that Achilles tendon procedures are an effective means of managing ulcerations in transmetatarsal amputation feet exhibiting an equinus deformity.

Sesamoidectomy for the treatment of chronic neuropathic ulcerations.

Neuropathic ulcerations in diabetic patients are frequent causes of hospitalizations and morbidity. The plantar aspect of the first metatarsophalangeal joint is a common location for these ulcerations, because of the significant weightbearing forces generated through this joint and the presence of sensory and motor neuropathy. The authors describe 24 cases in which excision of the tibial sesamoid, fibular sesamoid, or both, was performed to resolve these lesions.

Charcot's disease in diabetic patients. Correct diagnosis can prevent progressive deformity.

Although Charcot's disease and its association with diabetes have been described many times in the literature, it is still often misdiagnosed and incorrectly treated as osteomyelitis, arthritis, or gout. The best safeguard is a high index of suspicion. A warm, swollen foot in a diabetic patient with long-standing neuropathy without local or systemic signs of infection must be considered Charcot's disease until proven otherwise. The principal treatment is total abstinence from putting weight on the foot until warmth, swelling, and redness subside. Protective weight-bearing methods may then be slowly instituted.

Review of metatarsal osteotomies for the treatment of neuropathic ulcerations.

The records of 52 patients who underwent metatarsal osteotomies for the treatment of chronic neuropathic ulcerations between the years 1983 and 1985 were analyzed in a retrospective study. Long-term follow-up information was available for all but three patients. All patients were conservatively managed preoperatively and postoperatively with shoes, accommodative orthoses, and local care. A limb salvage rate of 94%, 46 of 49 patients, was achieved in this study. Although 13 patients developed transfer ulcerations, all but one were managed either with conservative care or a lesser podiatric procedure, and all remain healed to date.

Panmetatarsal head resection in chronic neuropathic ulceration.

Jacobs (1) reported use of the Clayton modification of the Hoffman procedure on 12 patients as the procedure of choice in select diabetics with abscess and ulceration. He described a dorsal transverse incision, amputation of all metatarsal heads, through-and-through drainage from a dorsal to plantar direction at the site of abscess formation, and use of a Jackson-Pratt drain dorso-laterally. The authors describe a modification of this procedure that has been performed for 6 years.