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Biomedical subjects

M Myerson

Publications and source records attributed to M Myerson.

At least 19 recordsLinked to original sources

High levels of Lp(a) with a small apo(a) isoform are associated with coronary artery disease in African American and white men.

Elevated levels of lipoprotein(a) [Lp(a)] and the presence of small isoforms of apolipoprotein(a) [apo(a)] have been associated with coronary artery disease (CAD) in whites but not in African Americans. Because of marked race/ethnicity differences in the distribution of Lp(a) levels across apo(a) sizes, we tested the hypothesis that apo(a) isoform size determines the association between Lp(a) and CAD. We related Lp(a) levels, apo(a) isoforms, and the levels of Lp(a) associated with different apo(a) isoforms to the presence of CAD (>/=50% stenosis) in 576 white and African American men and women. Only in white men were Lp(a) levels significantly higher among patients with CAD than in those without CAD (28.4 versus 16.5 mg/dL, respectively; P:=0.004), and only in this group was the presence of small apo(a) isoforms (<22 kringle 4 repeats) associated with CAD (P:=0.043). Elevated Lp(a) levels (>/=30 mg/dL) were found in 26% of whites and 68% of African Americans, and of those, 80% of whites but only 26% of African Americans had a small apo(a) isoform. Elevated Lp(a) levels with small apo(a) isoforms were significantly associated with CAD (P:<0.01) in African American and white men but not in women. This association remained significant after adjusting for age, diabetes mellitus, smoking, hypertension, HDL cholesterol, LDL cholesterol, and triglycerides. We conclude that elevated levels of Lp(a) with small apo(a) isoforms independently predict risk for CAD in African American and white men. Our study, by determining the predictive power of Lp(a) levels combined with apo(a) isoform size, provides an explanation for the apparent lack of association of either measure alone with CAD in African Americans. Furthermore, our results suggest that small apo(a) size confers atherogenicity to Lp(a).

Black or African American↗

Comparison of custom and prefabricated orthoses in the initial treatment of proximal plantar fasciitis.

Fifteen centers for orthopaedic treatment of the foot and ankle participated in a prospective randomized trial to compare several nonoperative treatments for proximal plantar fasciitis (heel pain syndrome). Included were 236 patients (160 women and 76 men) who were 16 years of age or older. Most reported duration of symptoms of 6 months or less. Patients with systemic disease, significant musculoskeletal complaints, sciatica, or local nerve entrapment were excluded. We randomized patients prospectively into five different treatment groups. All groups performed Achilles tendon- and plantar fascia-stretching in a similar manner. One group was treated with stretching only. The other four groups stretched and used one of four different shoe inserts, including a silicone heel pad, a felt pad, a rubber heel cup, or a custom-made polypropylene orthotic device. Patients were reevaluated after 8 weeks of treatment. The percentages improved in each group were: (1) silicone insert, 95%; (2) rubber insert, 88%; (3) felt insert, 81%; (4)stretching only, 72%; and (5) custom orthosis, 68%. Combining all the patients who used a prefabricated insert, we found that their improvement rates were higher than those assigned to stretching only (P = 0.022) and those who stretched and used a custom orthosis (P = 0.0074). We conclude that, when used in conjunction with a stretching program, a prefabricated shoe insert is more likely to produce improvement in symptoms as part of the initial treatment of proximal plantar fasciitis than a custom polypropylene orthotic device.

Adult↗

Arthrodesis of the first metatarsophalangeal joint: a biomechanical study of internal fixation techniques.

This study compares the strength and rigidity of four methods of internal fixation for arthrodesis of the first metatarsophalangeal joint. Ten matched pairs of cadaveric first rays were harvested and arthrodesis performed by one of four techniques: (1) planar excision of joint surfaces and fixation with crossed Kirschner wires, (2) planar excision of joint surfaces and internal fixation with a dorsal plate and screws, (3) planar excision of joint surfaces and internal fixation with an interfragmentary screw, or (4) excision of the joint surfaces using powered conical reamers and fixation with an interfragmentary lag screw. Biomechanical testing with a Bionix 858 materials testing machine was carried out, applying a plantar force utilizing principles of cantilever loading. Force applied and displacement of the arthrodesis were recorded. Of the four methods tested, bony preparation with power conical reamers and supplementary interfragmentary screw fixation was the most stable.

Arthrodesis↗

Late complications of fractures of the calcaneus.

We retrospectively reviewed the results of the operative treatment of forty-three fractures of the calcaneus in forty-two patients (thirty-six men and six women). The operations had been performed a mean of twenty-six months (range, six to seventy-two months) after the injury. An in situ subtalar arthrodesis had been performed in fifteen patients; a subtalar distraction bone-block arthrodesis, in fourteen; a triple arthrodesis, in five; a lateral calcaneal ostectomy, in seven; a transection and proximal transposition of the sural nerve, in seven; and a release of the tibial nerve, in five. The patients were examined at a mean of thirty-two months (range, twenty-six to fifty-two months) after the operation. The difference between the preoperative and postoperative rating scores was used to measure any improvement in function. Pain was partially relieved in thirty-eight (90 per cent) of the patients, function improved in thirty-five (83 per cent), and thirty-two (76 per cent) of the patients returned to work or to a pre-injury level of activity at a mean of eight months (range, four to sixteen months) after the operation. There was a trend (p = 0.07) that the longer the interval between the injury and the operation, the longer the subsequent interval until the patient returned to full activities or work. The most successful results were in the patients who had had a subtalar arthrodesis.

Activities of Daily Living↗

Salvage, with arthrodesis, in intractable diabetic neuropathic arthropathy of the foot and ankle.

Twenty-nine patients who had diabetic neuropathic arthropathy of the foot and ankle were managed with open reduction and arthrodesis of various joints. Rigid internal fixation was used in all but four patients, who had external fixation. All patients had severe instability or a fixed deformity that precluded successful treatment with bracing. The sites of the fracture-dislocations or the neuropathic dislocations were the ankle in twenty-one patients, the subtalar joint in six, and the transverse tarsal joint in two. The ankle-brachial Doppler indices of these patients averaged 0.86 (range, 0.55 to 1.14). The involved extremities were graded at the initial evaluations according to the Wagner classification system for neuropathic ulceration. The grade was 0 in fourteen patients, I in seven, II in two, and III in six. A tibiocalcaneal arthrodesis was performed after a talectomy in eleven patients; a tibiotalar arthrodesis, in eight; a triple arthrodesis, in six; a pantalar arthrodesis, in two; and a tibiotalocalcaneal arthrodesis, in two. Postoperatively, all patients remained non-weight-bearing and wore a below-the-knee plaster cast for two months. Weight-bearing was then begun with the leg in a total-contact plaster cast, and use of the cast was continued for a mean of five months (range, four to fourteen months). Thereafter, a polypropylene ankle-foot orthosis was used permanently. The most recent evaluation of the patients was performed at an average of forty-two months (range, fourteen to sixty-eight months) after the arthrodesis. There were twenty complications in nineteen of the twenty-nine patients, and there were nine pseudarthroses (six tibiocalcaneal, one tibiotalar, and two talonavicular). However, seven of the pseudarthroses were clinically stable. In these patients, the arthrodesis was performed as an alternative to amputation, and salvage was successful in twenty-seven (93 per cent) of the twenty-nine patients.

Adult↗

Compartment syndromes of the foot after calcaneal fractures.

Approximately 10% of calcaneal fractures develop compartment syndromes of the foot, and of these, one half develop clawing of the lesser toes and other foot deformities, including stiffness and neurovascular dysfunction. Tense swelling and severe pain are the hallmarks of an impending compartment syndrome. The diagnosis is confirmed by multistick invasive catheterization, particularly of the calcaneal compartment in the hindfoot. Immediate fasciotomy is recommended to prevent the development of ischemic contracture. It is recommended that open reduction and internal fixation of a calcaneal fracture is performed on a delayed basis, after the fasciotomy wounds are closed.

Calcaneus↗

The total-contact cast for management of neuropathic plantar ulceration of the foot.

Seventy-one neuropathic ulcers of the foot in sixty-six patients were treated with the use of a total-contact cast. The ulcers had been present for an average of five months (range, one to twenty-nine months) and were graded according to the Wagner classification; only patients who had grade-I or grade-II lesions were treated with a total-contact cast. The diameter of the ulcer averaged 3.5 centimeters (range, 1.5 to 15.5 centimeters). Sixty-four (90 per cent) of seventy-one ulcers were healed at a mean of five and one-half weeks (range, one to fourteen weeks). A deep infection developed in two patients during treatment. Twenty-two ulcers (31 per cent) recurred within eighteen months after initial healing; nineteen (86 per cent) of them healed after an average of two weeks in a second cast. Recurrent ulceration was usually associated with an underlying fixed deformity or osseous prominence. The total-contact cast provided safe, reliable, and cost-effective treatment for patients who had neuropathic ulcers of the foot.

Adult↗

Total body bone density in amenorrheic runners.

Many studies have suggested that the positive effect of running on bone mass does not fully compensate for the negative effects of athletic amenorrhea. These studies have made this conclusion based on measurements of bone at a limited number of sites. This study used dual-photon absorptiometry to measure bone mineral content and bone mineral density in the total body as well as in several regions in amenorrheic runners (N = 13), eumenorrheic runners (N = 13), and sedentary controls (N = 12). The subjects were 21-35 years old. Runners had run at least 40 km/week for at least the past 3 years. Controls had body mass indices similar to those of the runners. The amenorrheic women had significantly lower values for total bone mineral content (P = .01), total bone mineral density (P = .04), and total bone mineral content as a percent of normal values (P = .04) than eumenorrheic women, but they were not significantly different from the controls. When total bone mineral content and total bone mineral density were adjusted for body weight, there were no significant differences among the groups. The eumenorrheic subjects had significantly greater bone mineral density in the trunk than the amenorrheic women; eumenorrheics and controls had significantly greater bone mineral density in the spine compared with amenorrheics. Lumbar spine bone mineral density showed a trend toward greatest values for controls and lowest for amenorrheic women (P = .069), although this measurement is relatively imprecise. Arms and legs showed no significant differences among the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

Resting metabolic rate and energy balance in amenorrheic and eumenorrheic runners.

This study investigated metabolic and nutritional factors in association with athletic menstrual dysfunction (AMD). Three groups of women were studied: amenorrheic runners (amenorrheic), eumenorrheic runners (eumenorrheic), and eumenorrheic sedentary controls (sedentary). Amenorrheic and eumenorrheic were similar in age, weight, percent body fat by hydrodensitometry, training pace and mileage, best 10 km race time, years running, and maximal oxygen consumption. When adjusted for body weight or for fat-free mass by analysis of covariance, RMR was significantly lower in amenorrheic than in eumenorrheic and sedentary. The daily caloric intakes of the groups did not differ significantly, but the amenorrheic scored significantly higher than the eumenorrheic and sedentary on a scale of aberrant eating patterns. Amenorrheic high mileage runners seem to have a less adequate diet than eumenorrheic runners but appear to maintain energy balance and stable weight through a reduction in RMR.

Adaptation, Physiological↗

Posterior tibial tendon dysfunction: its association with seronegative inflammatory disease.

Idiopathic inflammation and rupture of the posterior tibial tendon (PTT) has received much attention in the recent literature. In this report of the presentation of PTT dysfunction as a manifestation of seronegative inflammatory disease, we describe the clinical and laboratory features of 76 patients with inflammation and/or rupture of the PTT. Analysis of all patients identified two discrete groups. Group A patients were younger (mean age 39 years) and had multiple manifestations of inflammation at other sites of ligament and tendon attachments (enthesopathy). Other features of a systemic inflammatory disorder such as oral ulcers, conjunctivitis, colitis, and especially psoriasis were common in the latter patients and their families. Group B consisted predominantly of elderly patients (mean age 64 years) with isolated dysfunction of the PTT. These two groups differed widely in the manner of clinical presentation, demographic data, family history, HLA data, and surgical pathology. These distinctions suggest different pathogeneses for posterior tibial tendinitis. Group A demonstrated local manifestations of a systemic inflammatory disease, whereas group B exhibited the effects of mechanical trauma and degeneration.

Adolescent↗

Split-thickness skin excision: its use for immediate wound care in crush injuries of the foot.

Split-thickness skin excision (STSE) was used as an adjunctive modality in the treatment of eight crush injuries of the foot. Compartment syndromes were present in four feet and were treated with fasciotomy. Wound debridement, internal fixation of fractures, and STSE followed. This technique accurately determined the viability of the skin flap, simultaneously providing skin for local wound coverage. All flaps treated in this manner survived and all (100%) of the degloved STSE grafts healed. Additional procedures were performed in four patients (two free flaps and two split-thickness skin grafts) adjacent to the debrided flap for complete coverage. STSE proved to be an effective modality for skin coverage in crush injuries of the foot associated with degloving of skin.

Adult↗

The diagnosis and treatment of injuries to the Lisfranc joint complex.

These injuries are associated with considerable morbidity, and successful results depend on understanding the anatomy, understanding pathogenesis, and precise and careful treatment of this injury. Surgical treatment is discussed as well as arguments against the use of conservative treatment.

Fractures, Bone↗

Acute compartment syndromes of the foot.

The early recognition and treatment of impending compartmental ischemia in the foot in the context of severe injuries will prevent the late sequelae of myoneural necrosis. When suspected, simple tests will confirm the diagnosis. If the clinical findings are equivocal, compartment pressure monitoring is an essential diagnostic tool. Methods of measuring compartment pressures in the foot are outlined. Prompt decompression of the compartment syndrome with appropriate fasciotomies either by medial or dorsal longitudinal incisions is indicated to preserve function and form of the foot.

Acute Disease↗