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Biomedical subjects

M K Allen

Publications and source records attributed to M K Allen.

At least 19 recordsLinked to original sources
PubMed2001

First ray dorsal mobility in relation to hallux valgus deformity and first intermetatarsal angle.

The hypermobile first ray has been implicated as contributing to the cause and progression of hallux valgus deformity. Deformity of the hallux is often accompanied by an enlarged first intermetatarsal (IM 1-2) angle. It has been hypothesized that subjects having an abnormally large IM 1-2 angle have laxity of the first ray. Objectives of this study were to compare dorsal mobility of the first ray in subjects with hallux valgus to asymptomatic controls, and to investigate the relationship between dorsal mobility and the IM 1-2 angle. Fourteen subjects (age 23-81) with hallux valgus were matched by gender and age to control subjects. The IM 1-2 angle was measured from radiographs. A load-cell device measured dorsal mobility of the first ray under a standard load of 55 N. Pearson's correlation coefficient identified a marginal correlation (r = .51) between IM 1-2 angle and dorsal mobility. An independent t-test showed a statistically (P < 0.01) larger amount of dorsal mobility in the group of subjects having hallux valgus. Mobility of the first ray was increased in subjects with hallux valgus and a large IM 1-2 angle may be an indicator of increased dorsal mobility.

Adult↗
PubMed2000

Comparison of first ray dorsal mobility among different forefoot alignments.

STUDY DESIGN: Experimental design using 1-way analysis of variance and regression analysis to test the influence of 3 forefoot alignments on the dorsal mobility of the first ray. OBJECTIVES: To determine the effect of forefoot alignment on the magnitude of first ray dorsal mobility to an imposed load and to describe any association between forefoot alignment and age on dorsal mobility of the first ray. BACKGROUND: Instability of the first ray has been implicated as a primary mechanical etiology of many foot problems. It has been proposed that a relationship exists between forefoot alignment and mobility of the first ray, with a varus aligned forefoot contributing to the development of an unstable first ray. METHODS AND MEASURES: Sixty female (n = 34) and male (n = 26) subjects aged 18-77 were assigned into valgus, neutral, and varus foot groups (20 per group) based on a clinical measurement of forefoot alignment. A load cell device measured dorsal mobility of the first ray under a standard load of 55 N. Within-day repeat measures were taken from a subsample of subjects. In addition to reliability analysis, analysis of variance and regression analyses tested the relationship between forefoot alignment, age and sex, and mobility of the first ray. RESULTS: The forefoot valgus group demonstrated significantly less dorsal mobility of the first ray than neutral or varus groups. The varus and neutral groups were not significantly different from one another. Forefoot alignment and sex were significant linear predictors (R2 = 0.40) of first ray dorsal mobility. Age had no significant association to dorsal mobility of the first ray. CONCLUSION: Subjects having a valgus aligned forefoot had less dorsal excursion of the first ray than subjects having a neutral aligned forefoot. This investigation provides evidence supporting a relationship between forefoot alignment and mobility of the first ray.

Adolescent↗
PubMed1999

Weight-bearing immobilization and early exercise treatment following a grade II lateral ankle sprain.

STUDY DESIGN: Case study. OBJECTIVES: To describe a protocol used in the rehabilitation of a grade II lateral ankle sprain, emphasizing brief immobilization with a removable boot, weight bearing as tolerated, and progression of early exercise. BACKGROUND: The optimum conservative treatment of severe grade II ankle sprains remains undefined. Short-term benefits of early mobilization have won favor over immobilization by casting; however, pain and ankle joint instability often linger. The timing of weight bearing as a variable that influences recovery has largely been ignored when either treatment is considered. METHODS AND MEASURES: The patient was a 17-year-old girl who had sustained a left ankle inversion sprain while playing high school basketball. The sprained ankle was placed in an immobilizer boot for 1 week, and weight bearing was encouraged. She received instructions for active exercise and for resistive exercise with elastic tubing. Volumetric and active range of motion measurements and gait observation provided indicators of rehabilitation progress. A digital inclinometer was used to measure active range of motion in the sagittal plane. Vertical ground reaction forces recorded with an instrumented treadmill documented gait symmetry. RESULTS: The patient responded well to the course of treatment, returning to full participation in basketball 2 weeks after the injury. The injured ankle had 29% (19 degrees) less active range of motion than the nonimpaired ankle at the beginning of physical therapy. The injured ankle also displaced 50 mL more water compared with the nonimpaired ankle at the start of treatment. Four weeks after beginning treatment, the sprained ankle had 4 degrees less active range of motion and displaced 5 mL more water compared with the nonimpaired ankle. As a college athlete, the patient has remained free of subjective complaints of ankle pain, instability, and swelling. CONCLUSION: Weight-bearing immobilization combined with early exercise provided safe and effective treatment for this patient, who suffered a grade II lateral ankle sprain.

Adolescent↗
PubMed1998

Measurement of dorsal mobility in the first ray: elimination of fat pad compression as a variable.

Previous designs for a device to measure first ray mobility have included compression of the first metatarsal fat pad as part of the measurement of displacement or have failed to standardize the force applied to the head of the first metatarsal. In this investigation, assessment of vertical mobility of the first ray of both feet in 14 volunteers was determined using a device that applied dorsiflexing force to the first metatarsal. First ray displacement was measured initially from the plantar surface and then from the dorsal aspect of the head of the first metatarsal. The difference between plantar- and dorsal-surface-measured vertical displacement was highly significant. This study suggests that mobility of the first ray measured from the dorsal aspect of the first metatarsal head eliminated compression of the plantar fat pad from being interpreted as part of the measurement of displacement.

Adipose Tissue↗
PubMed1995

Double jeopardy: thoracoabdominal injuries requiring surgical intervention in both chest and abdomen.

The critical decisions in patients with thoracoabdominal trauma are establishing the need to explore either or both cavities and determining appropriate sequencing. The causes and patterns of management difficulties were analyzed in 82 consecutive patients with penetrating thoracoabdominal injuries. Nine thoracotomies (11%) and 16 laparotomies (22%) were negative, with the major causes being misleading chest tube outputs, bullet trajectories, and abdominal tenderness. Inappropriate sequencing occurred in 19 patients (23%), and 15% required reoperation within 24 hours. Pitfalls and misjudgements in management of penetrating thoracoabdominal injuries occur in distinct patterns. The unreliability of chest tube output and abdominal examination must be kept in mind, and intraoperative clues of ongoing hemorrhage outside the operative field must be sought.

Abdominal Injuries↗
PubMed1994

Immediate versus delayed fluid resuscitation for hypotensive patients with penetrating torso injuries.

BACKGROUND: Fluid resuscitation may be detrimental when given before bleeding is controlled in patients with trauma. The purpose of this study was to determine the effects of delaying fluid resuscitation until the time of operative intervention in hypotensive patients with penetrating injuries to the torso. METHODS: We conducted a prospective trial comparing immediate and delayed fluid resuscitation in 598 adults with penetrating torso injuries who presented with a pre-hospital systolic blood pressure of < or = 90 mm Hg. The study setting was a city with a single centralized system of pre-hospital emergency care and a single receiving facility for patients with major trauma. Patients assigned to the immediate-resuscitation group received standard fluid resuscitation before they reached the hospital and in the trauma center, and those assigned to the delayed-resuscitation group received intravenous cannulation but no fluid resuscitation until they reached the operating room. RESULTS: Among the 289 patients who received delayed fluid resuscitation, 203 (70 percent) survived and were discharged from the hospital, as compared with 193 of the 309 patients (62 percent) who received immediate fluid resuscitation (P = 0.04). The mean estimated intraoperative blood loss was similar in the two groups. Among the 238 patients in the delayed-resuscitation group who survived to the postoperative period, 55 (23 percent) had one or more complications (adult respiratory distress syndrome, sepsis syndrome, acute renal failure, coagulopathy, wound infection, and pneumonia), as compared with 69 of the 227 patients (30 percent) in the immediate-resuscitation group (P = 0.08). The duration of hospitalization was shorter in the delayed-resuscitation group. CONCLUSIONS: For hypotensive patients with penetrating torso injuries, delay of aggressive fluid resuscitation until operative intervention improves the outcome.

Abdominal Injuries↗
PubMed1994

Causes and patterns of missed injuries in trauma.

Missed injuries have a bad reputation and are sometimes associated with serious morbidity for the patient and personal embarrassment for the surgeon. During a 10-year period, 123 missed injuries in 117 patients requiring re-operation were encountered in one trauma center. A retrospective review of causes and patterns was undertaken. The most common presentation was delayed hemorrhage (64 injuries). The colon, thoracic vasculature, chest wall arteries, and diaphragm were the most frequently involved sites. Forty-six injuries were overlooked during the diagnostic work-up, and 43 were missed during surgery. Technical problems with diagnosis and surgery accounted for 62% of missed injuries, whereas decision and judgment errors accounted for the rest. Further insight was provided by the classification of missed injuries into three types. Type I (20%) occurred outside the body area of clinical focus, whereas type II (69%) occurred within it. Type III (11%) resulted when instability of the patient necessitated interruption of the diagnostic work-up or exploration. Each type represents a different clinical pattern and dictates a specific preventive strategy.

Diagnostic Errors↗
PubMed1994

Ultrasound-guided cholecystocentesis in the owl monkey.

Bile samples were obtained from adult owl monkeys by ultrasound-guided percutaneous cholecystocentesis, using a transhepatic approach. Sampling frequency was once weekly over a 5-week period. Clinical recovery from each procedure was rapid. Animal body weights fluctuated within 22% of baseline over the study period, but maximal weight loss in any animal was less than 3% at the study's end. At necropsy, gross lesions in the liver and gallbladder were minimal. Histologic examination revealed mild focal cholecystitis in the gallbladder of four of six animals, focal pericholecystitis in three of six animals, and foci of gallbladder fibrosis in two animals. Changes were consistent with repeated trauma from the centesis procedure. Gallbladder mucosa was judged normal in all animals. Body weight fluctuations were attributed to a change in diet, part of a concurrent study, rather than to the centesis procedure. Ultrasound-guided cholecystocentesis provides a rapid, minimally traumatic, and safe method for repeated bile sampling in a small nonhuman primate.

Animals↗
PubMed1986

Penetrating wounds of the thorax.

While penetrating wounds of the thorax are rather uncommon in The Netherlands, they are frequently encountered in the emergency centres of the United States. Thoracic wall penetration may occur during times of warfare, during social altercations or as a result of industrial accidents. In civilian practice, such wounds are most often the result of injury with guns, knives or other sharp objects. Patients with penetrating thoracic wounds should be expeditiously transported to a trauma centre. Pre-hospital intravenous fluids, pleural decompression and anti-shock garments are contraindicated. On arrival in the emergency room, establishment of a patent airway, administration of intravenous fluids, pleural decompression and early X-ray examination of the chest are mandatory.

Diagnostic Tests, Routine↗
PubMed1986

Emergency thoracotomy for injury.

Emergency thoracotomy is required in 10-15 per cent of all patients with thoracic injury. Nine specific indications for emergency thoracotomy have been described for injured persons. A variety of incisions is available to the surgeon, and selection of the appropriate incision is based on radiographic and clinical findings. Thoracotomy in the emergency room is occasionally indicated, but it should be performed only by surgically trained individuals. Patients requiring emergency thoracotomy who are not dead on arrival have a greater than 75 per cent chance of survival.

Emergencies↗
PubMed1984

Emergency department treatment of chest injuries.

Injury to the chest accounts directly or indirectly for up to 50 per cent of deaths secondary to trauma. Eighty-five per cent of patients with chest injury may be managed by minor procedures available to the emergency physician. The indications for surgery in the remaining 15 per cent of patients with chest injury must be understood.

Cardiopulmonary Bypass↗
PubMed1979

Laparotomy in the emergency department.

Reports of advancements in emergency department operative resuscitative skills have included craniotomy, thoracotomy, cardiorrhaphy and even cardiopulmonary bypass. The efficacy and advisability of laparotomy in the emergency department remain in question. Between July, 1972, and July, 1977, adhering to an established protocol, resuscitative laparotomy was performed on 51 patients in the emergency department. All 51 patients underwent emergency thoracotomy also. Twenty-four patients were victims of gunshot wounds, 24 had sustained blunt trauma, and three had abdominal stab wounds. Injuries to the liver, major vessels, and spleen were most common. Control of hemorrhage by clamps, packs or pressure was the primary objective of laparotomy. Control of exsanguinating hemorrhage with precise application of vascular clamps was possible in all but 15 patients. Because of extensive multiple injuries and inability to achieve cardiovascular stability, only 11 patients reached the operating room, and none survived to leave the hospital. Although technically possible, laparotomy in the emergency center did not alter the fatal outcome of moribund patients in this series.

Abdominal Injuries↗
PubMed1978

Calcitriol in dialysis patients.

We conducted a 7-month randomized, single, double, single-blind comparison of calcitriol (1,25(OH)2D3) with vitamin D3 in 22 hemodialysis patients to study the effects on the biochemical abnormalities associated with osteodystrophy. Calcitriol was given for 3 mo. All patients had initial prestudy calcium values less than or equal to 9.5 mg/100 ml, and phosphate values less than or equal to 4.5 mg/100 ml. Data were analyzed using the Normalized Trend Index (NTI). Calcitriol induced a rise in calcium (8.7 to 10.25 mg/100 ml) (p less than 0.001) and a fall in alkaline phosphatase (p less than 0.005), while D3 had no appreciable effect. The mean dose of calcitriol during treatment was 0.579 microgram/day while that for D3 was 706 IU/day. The effect on serum phosphate concentration was variable. Hypercalcemia as high as 13.2 mg/100 ml occurred in 2 of 13 patients on 1,25(OH)2D3, but in every instance promptly returned to normal with dose reduction. No other adverse effects were noted with therapy. We conclude that calcitriol reverses the biochemical abnormalities of osteodystrophy. Since its effects are rapidly reversed with discontinuation, the drug is probably safe as well as effective.

Adult↗
PubMed1978

Suspecting thoracic aortic transection.

Deceleration accidents produce a complex of potentially fatal thoracic injuries. Because early detection is the key to successful management of blunt trauma to the great vessels, emergency physicians must be knowledgeable of signs indicative of these complex injuries. Among more than 10,000 patients presenting to the Ben Taub Emergency Center over an 11-year period with thoracic injuries, 100 had clinical or radiographic clues suggestive of blunt trauma decelerative injury to the great vessels. Of these 100 patients, 23 had transection of the descending thoracic aorta and five had avulsion of the innominate artery. One patient had a double transection. Six patients died in the Emergency Center before proximal control could be achieved.

Adolescent↗
PubMed1978

Scientific communications.

Scientific communications have two main forms, oral presentation at scientific meetings, accompanied by audio-visual aids, and manuscripts prepared for publication in scientific journals. In an oral presentation, the author should be prepared to speak for ten minutes, without depending on notes, and have prepared answers to anticipated questions. Slides are standard aids to summarize and reinforce the material. Preparation of manuscripts follows well-established guidelines available from scientific journals. Manuscripts should proceed from introduction to methods, results, discussion, and conclusion. Prior to writing, the author should answer the following: 1) What is the purpose of this communication? 2) How is this communication different from other data already in the literature? What is its unique contribution? 3) Who is the audience? Manuscripts will go through as many as seven drafts.

Communication↗