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M L Greenfield

Publications and source records attributed to M L Greenfield.

At least 19 recordsLinked to original sources
PubMed2000

Anterior cruciate ligament injuries in the female athlete. Potential risk factors.

In the general population, an estimated one in 3000 individuals sustains an anterior cruciate ligament injury per year in the United States, corresponding to an overall injury rate of approximately 100,000 injuries annually. This national estimate is low for women because anterior cruciate ligament injury rates are reported to be two to eight times higher in women than in men participating in the same sports, presenting a sizable health problem. With the growing participation of women in athletics and the debilitating nature of anterior cruciate ligament injuries, a better understanding of mechanisms of injury in women sustaining anterior cruciate ligament injuries is essential. Published studies strongly support noncontact mechanisms for anterior cruciate ligament tears in women, which make these injuries even more perplexing. Speculation on the possible etiology of anterior cruciate ligament injuries in women has centered on anatomic differences, joint laxity, hormones, and training techniques. Investigators have not agreed on causal factors for this injury, but they have started to profile the type of athlete who is at risk. In the current study the most recent scientific studies of intrinsic and extrinsic risk factors thought to be contributing to the high rate of female anterior cruciate ligament injuries will be reviewed, important differences will be highlighted, and recommendations proposed to alleviate or minimize these risk factors among female athletes will be reported where appropriate.

Anterior Cruciate Ligament Injuries↗
PubMed1999

Prospective analysis of ice hockey injuries at the Junior A level over the course of one season.

OBJECTIVE: This study was conducted to identify the circumstances, timing, frequency, and types of injuries for a Junior A hockey team in an attempt to develop injury prevention strategies. DESIGN: This study was a prospective review of injuries sustained by a hockey team during one season. SETTING: Players were evaluated in a private practice clinical setting and during practices and games. PARTICIPANTS: Twenty-two hockey players (16-20 years old) were evaluated. An injury was defined as any event requiring the attention of a physician or trainer. The players sustained 83 injuries throughout the course of the season. Seventy-four were considered independent events. MAIN OUTCOME MEASURES: The effects of the following variables on injury rates were analyzed: position, game situation versus practice, and timing of injury during the game. RESULTS: Players were 20 times more likely to injure themselves during a game than practice. Although forwards sustained the highest total percentage of injuries, defensemen had the highest incidence of injury in games. More injuries occurred in the later periods and in the later minutes of each period. Injury incidence decreased for the second half of the season compared with the first half. CONCLUSION: Our data suggest goaltenders are at the lowest risk of sustaining an injury, but forwards appear to be at a higher risk in practice situations and defensemen in games. Game situations place players at a much greater risk of injury than practice sessions, particularly in the later portions of each period and toward the end of the game. Given the propensity for injury in the early season and later in the game, endurance training before and during the season may be important in injury prevention.

Adolescent↗
PubMed1998

Decision-analysis methodology in the work-up of women with suspected silicone breast implant rupture.

Despite numerous studies advocating ultrasonography and magnetic resonance imaging (MRI) in the evaluation of women with possible silicone breast implant rupture, an appropriate algorithm has not been published for the optimal use of these tests. To derive a diagnostic algorithm using ultrasonography and MRI, we applied a decision-analytic model using Bayes' theorem to calculate the probabilities of implant rupture for three representative patient characteristics. A Medline search was conducted to identify literature related to the diagnosis of silicone breast implant rupture using ultrasonography and MRI since 1994. Also examined were case series of implant rupture to obtain rupture prevalence in cases in which rupture was dependent on patient presentation (symptomatic versus asymptomatic) and dependent on implant age. Test characteristics (sensitivity and specificity) and implant rupture prevalence are used to calculate the probability of rupture by using Bayes' theorem. These probabilities are derived for three patient categories: (1) asymptomatic, (2) symptomatic with implant age < or = 10 years, and (3) symptomatic with implant age >10 years. In asymptomatic patients, the pretest rupture prevalence is 6.5 percent. If a screening ultrasonography shows no rupture, the probability of rupture drops to 2.2 percent. If ultrasonography shows rupture, the probability of true rupture increases to 37.8 percent. Removal of implants in this setting will result in a high probability of extracting normal implants. However, if MRI after the ultrasonography shows rupture, the probability of true rupture increases to 86 percent, which gives better assurance of removing true-ruptured implants. In "symptomatic" patients (i.e., breast asymmetry, capsular contracture) with implants < or = 10 years old, the prevalence of rupture is estimated at 31 percent. If ultrasonography shows no rupture, the probability of rupture drops to 16 percent. If ultrasonography shows rupture, the probability of true rupture is 79.7 percent, and this probability increases to 97.5 percent if a follow-up MRI also shows rupture. In symptomatic patients with implants >10 years old, the prevalence of rupture is estimated at 64 percent. If ultrasonography shows rupture, the probability of true rupture increases to 94 percent, and no further diagnostic work-up is necessary. In an asymptomatic patient who is worried about the integrity of her implants, ultrasonography should be used as an initial diagnostic test because of its lower cost. If ultrasonography shows no rupture, no further work-up is necessary. If ultrasonography shows rupture, the low probability (37.8 percent) of true rupture requires a confirmatory test using MRI. In "symptomatic" patients, the high prevalence of rupture markedly raises the posttest probability of rupture for positive ultrasonography findings. Particularly in "symptomatic" patients with implants >10 years old, the high posttest probability of rupture (94 percent) with a positive ultrasonography obviates the need for any further diagnostic testing. This diagnostic algorithm will assist plastic surgeons in counseling women who are worried about the integrity of their silicone breast implants.

Bayes Theorem↗
PubMed1998

Endoscopic versus open carpal tunnel release: a cost-effectiveness analysis.

Endoscopic carpal tunnel release is a controversial procedure used in the treatment of carpal tunnel syndrome. Although endoscopic carpal tunnel release is associated with less incisional pain and faster recovery time than the open carpal tunnel release, opponents of endoscopic carpal tunnel release suggest that its benefits are outweighed by its higher complication rates from median nerve transection and transient numbness of the fingers. Because of the huge economic and social impact of carpal tunnel syndrome in this country, we performed a cost-effectiveness analysis comparing endoscopic carpal tunnel release and open carpal tunnel release using guidelines established by the Panel on Cost-Effectiveness in Health and Medicine of the U.S. Public Health Service. A decision analytic model was used to measure differences in cost and effectiveness--expressed as quality-adjusted life-years (QALYs)--between endoscopic carpal tunnel release and open carpal tunnel release. The societal perspective was chosen, and probabilities for various outcomes for the two procedures were obtained from published randomized-controlled trials. Cost data were derived from the Medicare Resource-Based Relative Value Units published in the Federal Register. QALYs were obtained from two groups of health care providers using a utility-assessment questionnaire. Using probabilities for various outcomes from the two published randomized-controlled trials comparing endoscopic carpal tunnel release and open carpal tunnel release, we constructed a decision tree to derive both the cost and the QALYs for the two procedures. The incremental cost difference between endoscopic carpal tunnel release and open carpal tunnel release was $46, using Medicare cost and probabilities of various outcomes derived from a study by Brown et al. in 1993. We calculated QALYs for five age groups--25, 35, 45, 55, 65--assuming a life expectancy of 75 years. The marginal effectiveness (QALY of endoscopic carpal tunnel release minus QALY of open carpal tunnel release) ranged from 0.235 QALY for the 25-year-old age group to 0.066 QALY for the 65-year-old age group, giving a cost-effectiveness ratio of $195/QALY and $693/QALY, respectively. When compared with other accepted medical interventions such as breast cancer screening ($4836/QALY) and exercise to prevent coronary heart disease ($13,508/QALY), endoscopic carpal tunnel release seems to be cost-effective. However, our sensitivity analysis indicated that the cost-effectiveness ratio was very sensitive to a major complication such as median nerve injury. For endoscopic carpal tunnel release to be a cost-effective procedure, the incidence of median nerve injury must be one percentage point less for endoscopic carpal tunnel release than for open carpal tunnel release. Based on the data from the randomized-controlled trials, endoscopic carpal tunnel release seems to be a cost-effective procedure; however, before it can be recommended, greater emphasis must be given to the training of surgeons in this new technique, so that major complications such as median nerve injuries can be avoided. In addition, future studies must better define the actual incidence of nerve injuries for both endoscopic carpal tunnel release and open carpal tunnel release in the community setting.

Adult↗
PubMed1998

Cervical spine alignment in immobilized hockey players: radiographic analysis with and without helmets and shoulder pads.

OBJECTIVE: To establish the appropriate technique for cervical immobilization of the hockey player with an acute neck injury, we analyzed the alignment of the cervical spine in healthy volunteers with combinations of applied hockey equipment and assessed the amount of cervical spine motion possible in a secured hockey helmet. Our hypothesis was that there is a significant difference among various positions of the cervical spine with and without equipment and with active motion in a secured helmet. DESIGN: We analyzed lateral cervical spine radiographs of eight healthy male volunteers immobilized on a backboard with the following combinations of hockey equipment: shoulder pads and helmet, shoulder pads only, helmet only, no equipment, and neck flexion and extension with helmet and shoulder pads on and helmet secured to the backboard. SETTING: Large university hospital, tertiary care center. RESULTS: Cervical lordosis without equipment (control) was not significantly different than cervical lordosis with shoulder pads and helmet applied (p=0.31). Subjects with shoulder pads averaged 8.9 degrees more lordosis than did controls (p= 0.0002) and 6.6 degrees more lordosis than did subjects with shoulder pads and helmets (p=0.027). Subjects with shoulder pads and a helmet secured to the backboard were able to flex and extend the cervical spine 12.9 degrees compared with the control position (p =0.009). CONCLUSIONS: In an acute cervical spine injury involving an ice hockey player, we recommend immobilization in both the helmet and the shoulder pads, with removal of both pieces of equipment in a controlled hospital setting and only after initial radiographic examination. We also recommend securing the player's chin to prevent as much head and neck motion as possible during transport and transfers.

Adult↗
PubMed1997

Extracorporeal life support for patients with significant orthopaedic trauma.

Extracorporeal life support is a therapeutic modality that can provide cardiorespiratory support for multiply injured patients. Fourteen patients with multiple trauma who sustained pelvic or long bone fractures were referred for treatment with extracorporeal life support at the University of Michigan Medical Center. All patients were considered morlbund secondary to their pulmonary injury. Six of the 14 patients had bilateral pulmonary contusions. The mean Injury Severity Score was 19. Twelve of the 14 patients had femoral or pelvic fractures or both. Eight patients had orthopaedic injuries initially treated with traction. The most common complication during extracorporeal life support management was bleeding, which occurred in eight of 14 patients. Eight of the 14 patients survived. Seven of eight patients with less than 6 days of mechanical ventilation before initiation of extracorporeal life support survived. Only one of six patients with six or more days of mechanical ventilation before initiation of extracorporeal life support survived. Patients with significant orthopaedic trauma and severe pulmonary compromise have an extremely high mortality risk. Appropriate aggressive fracture management remains the most important intervention to decrease the risk of pulmonary compromise. Early initiation of extracorporeal life support can be an additional lifesaving intervention in select patients with orthopaedic trauma who have respiratory failure refractory to conventional mechanical ventilation.

Adolescent↗
PubMed1997

Autogenous iliac crest bone graft. Complications and functional assessment.

Functional outcomes and complications experienced by adult patients who underwent iliac crest bone grafting were evaluated to assess the effect of bone grafts on patient function. In addition to retrospective chart reviews, patients completed the Sickness Impact Profile and a detailed questionnaire on pain. One hundred ninety-two patients met study inclusion criteria. Major complications were recorded in four (2.4%) patients in whom infections developed requiring readmission. Thirty-seven (21.8%) patients had minor complications. One hundred nineteen of 170 patients were available for followup; of these 119 patients, 87 (73.1%) returned completed questionnaires. Thirty-three of 87 (37.9%) patients reported pain 6 months postoperatively. The incidence of pain decreased with time, with 16 of 87 (18.7%) patients continuing to report pain more than 2 years postoperatively. Proportionately more spine patients reported pain at all time points. The mean Sickness Impact Profile score for patients completing questionnaires was nine, suggesting most patients were functioning well 2 years postoperatively. The morbidity of iliac crest grafting remains substantial. Pain symptoms in this study sample seemed to last longer in more patients than earlier series have indicated. Minimizing muscle dissection around donor sites and the advent of bone graft substitutes may help alleviate these problems.

Activities of Daily Living↗
PubMed1996

The role of melatonin in the pathogenesis of adolescent idiopathic scoliosis.

STUDY DESIGN: A matched, case-control study comparing melatonin production in female patients with and without adolescent idiopathic scoliosis. OBJECTIVES: To determine whether melatonin production is decreased in adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: A central etiology for idiopathic scoliosis has never been established. Previous authors have produced experimental scoliosis in chickens after pinealectomy, preventable by administration of melatonin. They suggested that a defect in melatonin synthesis might be involved in the pathogenesis of human idiopathic scoliosis. METHODS: Nine female adolescents with no medical problems, normal neurologic examinations, radiographic idiopathic scoliosis of 15-40 degrees, and Risser Stage I-III were in the patient group. Eighteen healthy adolescent girls with no medical problems, a negative school screening, and no family history of scoliosis were control subjects. Patients and control subjects were matched for age, weight, Tanner stage, sleep duration, and light exposure by multiple linear regression. Nighttime and daytime urine samples were analyzed for melatonin by high-performance liquid chromatography. RESULTS: Although nighttime melatonin levels were significantly higher than daytime levels in all volunteers (P < 0.00002), there were no significant differences in nighttime (P > 0.63) or daytime (P > 0.78) melatonin levels between patients and control subjects, even after matching by multiple linear regression analysis. A statistical analysis demonstrated that if a melatonin deficiency of 25% or more did exist in patients with scoliosis compared with control subjects, the likelihood that it would have been detected in this study was more than 98%. CONCLUSION: Although melatonin deficiency may cause scoliosis in the chicken, this study suggests that it is not a mechanism in the pathogenesis of adolescent idiopathic scoliosis in humans.

Adolescent↗
PubMed1994

Mortality after fracture of the hip in patients who have end-stage renal disease.

Thirteen fractures of the hip in twelve patients who had end-stage renal disease were treated over a ten-year period; these injuries included one intertrochanteric fracture, seven non-displaced fractures of the femoral neck, and five displaced fractures of the femoral neck. Twelve of the thirteen fractures were treated with an operation. Six patients (who had a total of six fractures) died within one year after the fracture. Two patients died as the result of sepsis related to the wound; the other four deaths were not directly related to the operation. Although the mortality rate in this group of patients was higher than that in a group of matched patients who had a fracture of the hip but who did not have end-stage renal disease, we were not able to demonstrate that this difference was significant, perhaps because of the small size of the sample. The mortality rate in these twelve patients was significantly higher, however, than that in matched patients who had end-stage renal disease but who did not have a fracture of the hip (p = 0.01).

Adult↗
PubMed1993

Applicability of the Greulich and Pyle skeletal age standards to black and white children of today.

OBJECTIVE: The Greulich and Pyle skeletal age atlas was derived from white children of upper socioeconomic level during the 1930s. To our knowledge, the Greulich and Pyle standards have not been reassessed for both black and white children; it was the purpose of this study to reassess the applicability of these standards to today's children. DESIGN: A "blinded" review of hand roentgenograms taken for the evaluation of trauma was performed. Age of the subjects was evenly distributed between 0 and 18 years. The roentgenograms were scored for bone age by five individuals from different disciplines and levels of training. The difference between the median bone age and the child's chronologic age was calculated for each roentgenogram and stratified into four age groups: early childhood (0 to 4 years), middle childhood (4 to 8 years), late childhood (8 to 13 years), and adolescence (13 to 18 years). SETTING: The roentgenograms were obtained from four hospital emergency rooms in the Lake Erie basin area, the same geographic area from which the Greulich and Pyle standards originated. PATIENTS: There were 841 children: 452 boys and 389 girls, 461 black and 380 white children. RESULTS: The bone ages and chronologic ages were similar for white girls of all ages. Black girls were skeletally advanced by 0.4 to 0.7 year (P < .001), except during middle childhood. White boys were skeletally delayed during middle childhood by 0.9 year (P < .001) and during late childhood by 0.4 year (P < .01), but they were advanced during the adolescent years by 0.5 year (P < .01). Black boys showed no difference except for the adolescent group, which was skeletally advanced by 0.4 year (P < .02). CONCLUSIONS: The Greulich and Pyle atlas is not applicable to all children today, especially black girls. We should be aware of this information when making clinical decisions requiring accurate bone ages.

Adolescent↗
PubMed1993

The epidemiology of bilateral slipped capital femoral epiphysis. A study of children in Michigan.

The records of 224 children who had a slipped capital femoral epiphysis and who had no underlying metabolic or endocrine disorder were studied retrospectively to investigate the epidemiology of bilateral slipped capital femoral epiphysis. Eighty-two (37 per cent) of the 224 children (fifty-one boys and thirty-one girls) had a bilateral slip. Sixty-four of these children were black and eighteen were white. The age at the time of the diagnosis of the first slip was 13 +/- 1.7 years (mean and standard deviation), the duration of the symptoms was 5 +/- 5.0 months, and the angle of the slip was 26 +/- 16 degrees. Obese children were younger at the time of the diagnosis of the first slip (12 +/- 1.6 compared with 13 +/- 1.6 years for the children who were not obese, p = 0.001). The diagnosis of a slipped capital femoral epiphysis was made simultaneously in both hips in forty-one children and sequentially in forty-one children. Compared with the children in whom both hips were diagnosed simultaneously, the children in whom the hips were diagnosed sequentially had had a shorter duration of the symptoms before the diagnosis of the first slip (3 +/- 2.4 compared with 7 +/- 5.9 months, p = 0.0003), were younger at the time of the diagnosis of the first slip (12 +/- 1.9 compared with 13 +/- 1.2 years, p = 0.001), and tended to be more obese (p = 0.025). In 88 per cent of the patients who had sequential slips, the second slip was diagnosed within eighteen months after the diagnosis of the first slip.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

The low incidence of suprascapular nerve injury after primary repair of massive rotator cuff tears.

We measured the incidence of cuff retear and injury to the suprascapular nerve after mobilization and repair of a massive rotator cuff tear. Of one hundred four rotator cuff repairs performed over a 5-year period, 10 patients (7 men and 3 women, age range 22 to 68 years) had primary repairs of massive rotator cuff tears requiring cuff mobilization and an acromioplasty as their only procedure. These patients were evaluated at a mean of 2.5 years (range 2.0 to 3.0 years) after surgery. At follow-up electromyographic examination confirmed that 1 of the 10 patients had an iatrogenic suprascapular nerve injury, whereas ultrasound evaluation revealed that 2 of 10 repairs failed. Pain relief was achieved in the eight patients with intact repairs and not in the two with recurrent tears. All patients had some limitation of active motion or strength, especially in external rotation. Thus 7 of 10 patients had neither evidence of nerve injury nor recurrent rotator cuff tears yet still showed limited active motion or weakness. It appears that operative injury to the suprascapular nerve during cuff mobilization can occur, but other factors such as inadequate cuff muscle function are more frequently responsible for the poor functional outcomes seen after successful repairs of massive rotator cuff tears.

Adult↗
PubMedDate not supplied

Lower extremity lawn-mower injuries in children.

Lower extremity lawn-mower injuries in children result in significant morbidity with a significant financial burden to the family and society. We reviewed 24 children with lower extremity lawn-mower injuries; all mothers completed standardized psychologic assessments of their children, and 18 children were interviewed. Fifty percent of the mothers had defensive profiles on the standardized psychologic assessment, suggesting the likelihood of denial or underreporting of the child's psychologic difficulties. Therefore, we found the interview with the child to be a more accurate measure of psychologic distress. Prevention measures aimed at parents must emphasize that a child must not be allowed in a yard that is being mowed with a riding mower.

Accident Prevention↗
PubMedDate not supplied

The psychosocial characteristics of children with fractures.

We examined the psychosocial characteristics of 52 children with fractures. The parents completed questionnaires regarding injury circumstances, family functioning, home environment, and child behavior. Established psychosocial questionnaires were used: the McMaster Family Assessment Device (family environment), the Conners Parent Symptom Questionnaire, and Achenback Child Behavior Checklist (child behavior). Parent's perception of family functioning fell within the average range. The children exhibited a significantly high degree of social competence problems as well as behavioral difficulties. These behavioral difficulties included conduct disorder features, psychosomatic complaints, and impulsive/hyperactive behavior. To the extent that these variables constitute risk factors unique to children with fractures, prevention strategies can be designed to decrease the incidence of pediatric fractures.

Child↗