Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Hand”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,405 records · Page 78Linked to original sources
PubMed2003

The effect of hand hygiene on illness rate among students in university residence halls.

BACKGROUND: Several studies have indicated a connection between hand sanitization and infection control in numerous settings such as extended care facilities, schools, and hospitals. The purpose of this study was to assess the effectiveness of both a hand-hygiene message campaign and the use of an alcohol gel hand sanitizer in decreasing the incidence of upper-respiratory illness among students living in university residence halls. METHOD: This study involved a total of 430 students recruited from 4 residence halls during the fall semester at the University of Colorado at the Boulder campus. Dormitories were paired into control and product groups. In the product groups, alcohol gel hand-sanitizer dispensers were installed in every room, bathroom, and dining hall. The data were statistically analyzed for the differences between product and control groups in reported symptoms, illness rates, and absenteeism from classes. RESULTS: The overall increase in hand-hygiene behavior and reduction in symptoms, illness rates, and absenteeism between the product group and control group was statistically significant. Reductions in upper respiratory-illness symptoms ranged from 14.8% to 39.9%. Total improvement in illness rate was 20%. The product group had 43% less missed school/work days. CONCLUSION: Hand-hygiene practices were improved with increased frequency of handwashing through increasing awareness of the importance of hand hygiene, and the use of alcohol gel hand sanitizer in university dormitories. This resulted in fewer upper respiratory-illness symptoms, lower illness rates, and lower absenteeism.

Adolescent↗
PubMed1983

[The prefiguration of a museum of the Hand of Man].

The author has created a foundation, acknowledged as being of public benefit, whose purpose is to set up a "Museum of the Hand of Man", conceived as a coordination and research center on the hand. An attempt at systematizing a prefiguration of this institution is proposed, with five subsectors: the original of this institution is proposed, with five subsectors: the original hand, the experienced hand, the hand and culture, the hand and society, and the hand as a symbol. In addition, a collection of publications on these various aspects of the hand is projected.

Art↗
PubMedDate not supplied

Practice analysis of hand therapy.

In 1994, a practice analysis (role delineation study) was conducted on the profession of hand therapy. This study was conducted as a follow-up to the original study conducted by the American Society of Hand Therapists (ASHT) in 1985. A representative group of content experts developed a description of hand-therapy practice, and this description was validated using a questionnaire. The questionnaire was distributed to a random sample of 400 certified hand therapists (CHTs), of whom 50% responded. The respondents provided confirmation of the accuracy of the description of hand therapy. The survey results were used to update the test specifications for the Hand Therapy Certification Examination. The results enabled the Hand Therapy Certification Commission to improve upon its certification program by clarifying and expanding the definition of hand therapy. The 1994 findings were also compared with the results of the 1985 study.

Certification↗
PubMed1998

A neuromagnetic normative data set for hemispheric sensory hand cortical representations and their interhemispheric differences.

Somatotopy of human hand primary sensory cortex has been studied neuromagnetically [C. Baumgartner, A. Doppelbauer, L. Deecke, D.S. Barth, J. Zeitlhofer, G. Lindinger, W.W. Sutherling, Neuromagnetic investigation of somatotopy of human hand somatosensory cortex, Exp. Brain Res. 87 (1991) 641-648.] [1]. Investigation of sensory cortex devoted to the hand will be of major importance in relation to clinical recovery after sensorimotor deficits as well as an index of plasticity phenomena following alterations of peripheral nerves inputs. Here a normative data set has been constructed, on the basis of the neuromagnetic investigation of the primary sensory hand cortical representation in the two hemispheres of 20 healthy volunteers. This can be used to evaluate interhemispheric differences of the 'sensory' hand areas during experimental paradigms in the healthy as well as following patients with monohemispheric lesions. The localizations in each hemisphere of the cortical Equivalent Current Dipoles (ECDs) activated with the shortest latencies (N20m and P30m components) by separate stimulation of left and right median nerve, thumb and little finger were analysed. By considering the ECDs to thumb and little finger stimulation the boundaries of the hand cortical representation in primary sensory cortex, the 'hand extension' was measured as the distance between the two. For all the considered parameters (related to N20m and P30m ECDs: latency, strength, spatial position in the individual head, 'hand extension', interhemispheric differences) the appropriate variable distribution was considered and by including the 98% of the healthy population normative limits were calculated.

Adult↗
PubMed2001

Effects of alkalinity of household dishwashing liquids on hand skin.

The objective of this research was to investigate the effects of alkaline pH conditions of dishwashing liquids on hand skin of Korean panelists after repeated exposure. A group of 30 persons with normal hands immersed their hands, for a total of 15 min a day for 4 days, into household cleansing solutions adjusted to pH 7.4, 10.0 and 10.8, respectively. The effects of alkalinity of household cleansing solutions on hand skin were evaluated by measuring overall and dry hand-skin grades, as well as the degrees of hand-skin hydration estimated before and after the repeated immersion exposures to the 3 test products. No statistically-significant difference (p>0.05) was found among the parameters from the repeated immersion exposures to the test products. These findings indicate that increases of pH up to 10.8 of household cleansing solutions did not worsen either overall, dry hand-skin conditions or the level of hand-skin hydration.

Dermatitis, Allergic Contact↗
PubMed2003

A randomized comparison of an emollient containing skin-related lipids with a petrolatum-based emollient as adjunct in the treatment of chronic hand dermatitis.

Hand dermatitis is a multifactorial skin disorder in which skin barrier impairment is involved in the pathogenesis. The development of topical agents that improve skin barrier function is therefore a promising approach for the management of hand dermatitis. Topically applied lipids may interfere with skin barrier function, and emollients containing skin-related lipids have been suggested to facilitate repair of the skin barrier. However, evidence for the superiority of emollients containing skin-related lipids over the more traditional emollients is still lacking. The aim of this study was to compare an emollient containing skin-related lipids (Locobase Repair) with a traditional petrolatum-based emollient for the management of hand dermatitis. Adult males and females (n = 30) with mild to moderate chronic hand dermatitis were treated twice daily for 2 months either with an emollient containing skin-related lipids or with a pet.-based emollient. In the case of exacerbation, the patients of both treatment groups were allowed to use a mild corticosteroid according to instructions. Both treatment regimes significantly improved clinical signs of hand dermatitis as assessed by the investigator global assessment, hand eczema area and severity score. We did not observe significant differences in the improvement of clinical signs, itching, patients' assessment of efficacy, cosmetic acceptability or usage of topical corticosteroids between both treatment groups. In conclusion, this study confirms that the frequent use of emollients may be useful in the therapy of hand dermatitis. However, we could not demonstrate the superiority of this particular emollient containing skin-related lipids in patients with chronic hand dermatitis.

Administration, Topical↗
PubMed2006

Young children's hand contact activities: an observational study via videotaping in primarily outdoor residential settings.

Microlevel activity time series (MLATS) data were gathered on hand contact activities of 38 children (1-6 years old) by videotaping in primarily outdoor residential environments. The videotape recordings were then translated into text files using a specialized software called VirtualTimingDevicetrade mark. Contact frequency (contacts/h), duration per contact (s/contact), and hourly contact duration (min/h) were summarized for outdoor hand contacts with 15 distinct object/surface categories ("Animal", "Body", "Clothes/Towels", "Fabric", "Floor", "Food", "Footwear", "Metal", "Non-dietary Water", "Paper/Wrapper", "Plastic", "Rock/Brick", "Toys", "Vegetation/Grass", and "Wood") and two aggregate object/surface categories ("Non-dietary objects/surfaces" and "Total objects/surfaces"). For outdoor both hand contacts with "Total objects/surfaces", contact frequencies ranged from 229.9 to 1517.7 contacts/h, median durations/contact ranged from < 1 to 5 s, and hourly contact durations ranged from 42.6 to 102.2 m/h. The data were analyzed for significant differences in hand contact activities as a function of (1) age, (2) location, (3) gender, and (4) hand. Significant differences (P < or = 0.05) were found for all four factors analyzed. Hourly contact durations with "Non-dietary objects/surfaces" and "Total objects/surfaces" increased with age (P = 0.01, rs = 0.42 and P = 0.005, rs = 0.46, respectively), while contact frequencies and hourly contact durations with "Wood" decreased with age (P = 0.02, rs = -0.38 and P = 0.05, rs = -0.32, respectively). Location was found to affect contact frequencies and hourly contact durations with certain objects/surfaces. For example, contact frequencies and hourly contact durations with "Fabric" were higher indoors (P = 0.02 for both), while contact frequencies and hourly contact durations with "Vegetation/Grass" were higher outdoors (P = 0.02 and P = 0.04, respectively). Girls had longer hourly contact durations with "Footwear" (P = 0.02), "Non-dietary objects/surfaces" (P = 0.03), and "Total objects/surfaces" (P = 0.01) than boys. The right hand had longer hourly contact durations with objects that are often manipulated with the hand (e.g., "Toys" (P = 0.0002)), while the left hand had longer hourly contact durations with passively touched objects/surfaces (e.g., "Clothes/Towels" (P = 0.003) and "Floor" (P = 0.04)).

Behavior↗
PubMed1998

Functional hand development in tetraplegia.

The development of the 'functional hand' in tetraplegics has been historically facilitated through specialized hand positioning schemes. However, clinical experience at the University Hospital Heidelberg demonstrates no direct relationship between various hand positioning techniques and the probability of functional hand development. The aim of this study was to document the various methods of hand positioning and the resulting functional outcome. In a multi-center study, the paralysed thumb and finger positioning of 64 tetraplegics and the resultant functional outcome was evaluated with a specially developed survey form. Results indicated that the functional outcome of the tetraplegic hand was highly dependent on the level of the spinal cord injury and only to a minor degree dependent upon the different methods of hand positioning employed. The conclusion drawn is that remaining neurologic function after injury determines the final functional outcome of the tetraplegic hand.

Adolescent↗
PubMed1990

Cutaneous vascular responses evoked in the hand by the cold pressor test and by mental arithmetic.

1. Laser Doppler flowmetry has been used to study changes in cutaneous erythrocyte flux produced in the hand (i) on successive immersion of the contralateral hand in water at 20 degrees C (cold test) and then in water at 0-4 degrees C (cold pressor test), and (ii) by mental arithmetic. 2. In 11 subjects, placing the right hand in water at 20 degrees C for 2 min induced a significant decrease in cutaneous erythrocyte flux in the contralateral hand and a significant fall in mean arterial pressure. Cutaneous vascular resistance, calculated as arterial pressure/cutaneous erythrocyte flux, showed no significant change. Thus, the decrease in erythrocyte flux was apparently due to a fall in perfusion pressure. 3. Subsequent immersion of the right hand in water at 0-4 degrees C for 2 min caused a significant decrease in erythrocyte flux in the contralateral hand and a significant rise in mean arterial pressure. It is concluded that the cold pressor response evoked from one hand elicited a substantial reflex vasoconstriction in the skin of the other hand; accordingly, calculated cutaneous vascular resistance increased significantly. 4. Eight subjects performed mental arithmetic for two periods of 2 min separated by a rest period of 2 min. By the end of the second minute of each period of mental arithmetic there was a significant decrease in erythrocyte flux. Mean arterial pressure increased significantly in the first period only, but calculated cutaneous vascular resistance increased in both periods, consistent with cutaneous vasoconstriction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2001

Prevalence of atopic dermatitis, asthma, allergic rhinitis, and hand and contact dermatitis in adolescents. The Odense Adolescence Cohort Study on Atopic Diseases and Dermatitis.

BACKGROUND: Atopic diseases are common in children and adolescents. However, epidemiological knowledge is sparse for hand eczema and allergic contact dermatitis in this age group. Furthermore, no population-based studies have evaluated the prevalence of atopic diseases and hand and contact dermatitis in the same group of adolescents. OBJECTIVES: To assess prevalence measures of atopic dermatitis (AD), asthma, allergic rhinitis and hand and contact dermatitis in adolescents in Odense municipality, Denmark. METHODS: The study was carried out as a cross-sectional study among 1501 eighth grade school children (age 12-16 years) and included questionnaire, interview, clinical examination and patch testing. RESULTS: The lifetime prevalence of AD was 21.3% (girls 25.7% vs. boys 17.0%, P < 0.001) using predefined questionnaire criteria. The 1-year period prevalence of AD was 6.7% and the point prevalence 3.6% (Hanifin and Rajka criteria). In the interview the lifetime prevalence of inhalant allergy was estimated as 17.7% (6.9% allergic asthma, 15.7% allergic rhinitis). The lifetime prevalence of hand eczema based on the questionnaire was 9.2%, the 1-year period prevalence was 7.3% and the point prevalence 3.2%, with a significant predominance in girls. A significant association was found both between AD and inhalant allergy, and between AD and hand eczema using lifetime prevalence measures. The point prevalence of contact allergy was 15.2% (girls 19.4% vs. boys 10.3%, P < 0.001), and present or past allergic contact dermatitis was found in 7.2% (girls 11.3% vs. boys 2.5%). Contact allergy was most common to nickel (8.6%) and fragrance mix (1.8%). CONCLUSIONS: High prevalence figures were found for atopic diseases, hand eczema and allergic contact dermatitis, and the diseases were closely associated. A considerable number of adolescents still suffers from AD, and a considerable sex difference was noted for hand eczema and allergic contact dermatitis. Nickel allergy and perfume allergy were the major contact allergies. In the future this cohort of eighth grade school children will be followed up with regard to the course and development of atopic diseases, hand eczema and contact dermatitis.

Adolescent↗
PubMed2002

Hand eczema in Swedish adults - changes in prevalence between 1983 and 1996.

Hand eczema is the most frequent occupational skin disease. Our aim was to study changes in its prevalence in Swedish adults. Cross-sectional studies were performed in 1983 and 1996. Random samples from the population of Gothenburg, Sweden, aged 20-65 y, were drawn from the population register. Data were collected with a postal questionnaire, which was identical in the two studies. The response rate was 83.5% (16,708 out of 20,000) in 1983 and 73.9% (2218 out of 3000) in 1996. The reported 1 y prevalence of hand eczema decreased from 11.8% in 1983 to 9.7% in 1996 (p < 0.01), a large difference being found in the youngest age group. Reported childhood eczema increased from 10.4% to 12.4%, however (p < 0.01). Of those with childhood eczema 27.9% and 25.2% reported hand eczema, compared to 10.0% and 7.5% among those without childhood eczema. In total 76.8% were gainfully employed in 1983 and 68.3% in 1996 (p < 0.001). In 1983 23.0% were employed in "high-risk" occupations for hand eczema compared to 19.4% in 1996 (p < 0.001). Even though the increase in childhood eczema was largest in the youngest group, there was a large decrease in the prevalence of hand eczema in that age group among both sexes. The study indicates that the prevalence of hand eczema in Swedish adults had decreased between 1983 and 1996 despite an increasing prevalence of childhood eczema. Secular changes in reporting hand eczema and childhood eczema may explain some of the changes, but a decreased occupational exposure to skin irritants is a probable cause, implying that occupational factors may be important predictors of hand eczema.

Adult↗
PubMed1999

Erbium:YAG laser resurfacing of the hands, arms, and neck.

BACKGROUND: Resurfacing procedures to improve photodamage, rhytides, and scars have been developed and refined over the last century. Laser resurfacing is a relatively new procedure in the resurfacing spectrum. It has been appreciated that resurfacing of nonfacial skin by dermabrasion, chemical peels, or carbon dioxide (CO2) laser carries an unacceptably high risk of scarring. More recently, the erbium:YAG (Er:YAG) laser has been developed and marketed for facial and nonfacial resurfacing. Specifically, manufacturers have promoted Er:YAG lasers as safe for resurfacing photodamaged skin on the hands, forearms, and neck. Surprisingly, there is little evidence to support these claims. OBJECTIVE: To evaluate the safety and efficacy of resurfacing photodamaged skin on the dorsum of the hands, forearms, and neck with an Er:YAG laser. METHODS: Twelve patients with photodamage of the neck or of the hands and forearms participated in this study. Seven patients received laser resurfacing of the hands and forearms utilizing the Er:YAG laser with a 5 mm spot size at an energy of 1 J (5 J/cm2). These patients received 2 to 3 passes. Five patients received resurfacing of photodamaged neck skin with a 5 mm spot size at 1 J (5 J/cm2). These patients received one to 2 passes. Patients were evaluated for time to healing, cosmetic improvement, and satisfaction with the procedure. RESULTS: Several observations of note are reported in patients receiving nonfacial resurfacing. Despite previous reports of patients receiving Er:YAG laser treatment with topical anesthesia alone, all patients required some intralesional anesthesia during the procedure for some areas. All patients required significantly longer to heal as compared to the face. Both the hands and forearms and the neck require 2-3 weeks to heal. Two of 7 hand and forearm patients developed bacterial infections during healing. One of 5 neck resurfacing patients developed transitory hyperpigmentation. Cosmetic improvement was mild, with 6 of 7 hand and forearm patients showing poor (0-25%) cosmetic improvement and one of 7 showing fair (25-50%) improvement. In the neck resurfacing group, 3 of 5 had poor (0-25%) improvement, one of 5 had fair (25-50%) improvement, and one of 5 had good (50-75%) results. CONCLUSION: Er:YAG laser resurfacing of the hands, forearms, and neck may be safely performed. Topical anesthesia alone is inadequate, healing takes up to 3 weeks, and cosmetic improvement is minimal with the parameters used in this study.

Adult↗
PubMed2000

The fate of the dorsal metacarpal arterial system following thermal injury to the dorsal hand: A Doppler sonographic study.

Hands are involved in over 70% of all serious burns. This study comprised 80 hands in 41 patients with burns of the dorsum of the hand. Eighty percent of the hands in our study had deep partial-thickness and full-thickness burns that had to be grafted. This study was performed to evaluate the patency of the dorsal metacarpal artery (DMCA) system in burn-injured hands. Sixteen hands healed spontaneously; 62 had to be excised and grafted. Doppler mapping of the dorsum of the hand was completed using an 8-MHz probe. Patent vessels were found in a pattern similar to that of a normal population in spontaneously healed and grafted partial-thickness burns. The incidence of dorsal arteries decreased from 100% for the first DMCA to 80% for the DMCA in the fourth web space. In full-thickness burns the correlation of burned hands to normal volunteers was only 80%. It can be concluded from the data that the DMCA system is not damaged by deep partial-thickness burns that are excised and grafted. The DMCA system is still intact in 80% of patients with full-thickness burns. The potential for elevating a DMCA flap is therefore preserved after burn excision and grafting. Preoperative Doppler examinations are recommended before planning the flaps.

Adolescent↗
PubMed1999

A comparison of dominant and non-dominant hand strengths.

This study compares dominant and non-dominant hand strength in both right- and left-handed participants. Maximum voluntary contraction (MVC) of the first dorsal interosseous (FDI) muscle, power grip strength and pulp-to-pulp pinch strength were assessed under carefully controlled conditions. No significant differences were observed between dominant and non-dominant hands in left-handed participants for all tests. Small but significant differences (0.1-3%) were observed between dominant and non-dominant hands in right-handed participants for all three tests. These differences were much smaller than those reported in other studies. Furthermore, considerable variability was observed in the relative strengths of the two hands for each participant. We conclude that clinicians must be cautious when using the '10% rule' to make comparisons between injured and uninjured hands.

Adult↗
PubMed2001

[Defect coverage of the hand and forearm with a free scapula-parascapula flap].

BACKGROUND: Complex defects of the forearm and hand are associated with the loss of important structures. Single-stage reconstruction of these defects requires composite tissue transplantations. The subscapular region offers various components for the coverage of complex defects. The scapular and the parascapular flaps can be used each as cutaneous, fasciocutaneous and osteocutaneous or as a combined flap as well. The purpose of this study was to present our experience with the combined scapular-parascapular free flap for defect coverage of the forearm and hand in 13 patients. PATIENTS AND METHOD: Evaluation of 12 patients who underwent coverage of forearm and hand defects with the combined scapular-parascapular free flap during a five-year period. Other treatment options are discussed. RESULTS: Average age of the patients was 39 years, there were ten male and two female patients. Average follow-up was 20 months. Eleven patients suffered from massive trauma, one patient from severe infection of the forearm and hand. The defect size varied from 12 x 8 cm to 45 x 20 cm. In nine cases, a cutaneous and/or fasciocutaneous scapular-parascapular flap was used, two patients underwent defect coverage with an osteocutaneous scapular-parascapular flap, and in one patient, a "four-flap-mega-flap" was transplanted. One flap developed a partial necrosis. Eight patients developed a good or very good functional outcome with their hand and forearm, two patients have a moderate degree of disability. Two patients can use their hand as a supporting hand. CONCLUSION: This study demonstrates that the combined scapular-parascapular free flap is a reliable treatment choice for early coverage of defects of the forearm and hand. The advantages are the long, large and consistent vascular pedicle, the possibility of combination with other flaps and "custom-tailoring", including whatever component is necessary to close the particular defect.

Adult↗
PubMed2001

[Compliance with hand hygiene in intensive care units].

INTRODUCTION: Nosocomial infections are an important problem in modern hospitals. The prevalence in German intensive care units is 15.3%. Hand washing or hand disinfection is believed to be the most important means of preventing nosocomial infections. We wished to answer the following questions: 1. How good is the compliance of hand hygiene on intensive care units? 2. Is compliance associated with the patient/nurse-ratio? METHOD: In a study of 8 intensive care units the compliance of hand hygiene was observed on two occasions, once in May 1996 and again in November 1997. The prime necessity for hand disinfection occurred when handling ventilation devices, intravascular catheters, urinary catheters and dressings. In addition the patient/nurse-ratio was calculated. RESULTS: A total of 1,879 infection-relevant handlings were observed. The compliance of hand hygiene ranged from 25.7 to 83.2% (mean 55.2%). The most commonly observed handlings were the manipulation of venous catheters (52.7%), the highest compliance was observed with the manipulation of ventilation equipment (91.8%). With a better patient nurse ratio the compliance did not improve but remained the same or was even reduced. DISCUSSION: The compliance of hand disinfection is similar to other study results, but on some intensive care units there was considerable room for improvement. In this study the compliance of hand hygiene is more of a constant factor in individual intensive care units than associated with the patient/nurse-ratio.

Attitude of Health Personnel↗
PubMed2002

[Dystrophic epidermolysis bullosa: surgical treatment of advanced hand deformities].

Dystrophic epidermolysis bullosa (Hallopeau-Siemens, recessive dystrophic epidermolysis bullosa) is a rare inherited disorder of the skin and mucosa, characterized by blistering in response to the slightest mechanical trauma. Healing is associated with scarring and the formation of contractures and milia. Following repetitive trauma (friction), this process leads to severe hand deformities with digits contracted in flexion, the thumb contracted in adduction and pseudo-syndactyly. In advanced cases (as described here), the hands show a mitten-like deformity and digits are encased in an epidermal "cocoon". This results in complete loss of function with major consequences for both the patient's (children's) daily life and their psychosocial development. We demonstrate the advantages of the (simplified) surgical procedure including "de-cocooning"/degloving, syndactyly-release, release of the thumb and the digital joint contractures and Kirschner-wire stabilization. Spontaneous epithelialisation of skin defects proved to be unproblematic and advantageous compared to skin transplantations, flaps, keratinocyte transplantations and other more ambitious procedures. Reviewing the published long-term results of other methods, we favour the procedure described because it simplifies and accelerates the overall treatment. From 1998 to 2001, we treated three children with recessive dystrophic epidermolysis bullosa and five hands were operated. A total number of 23 interventions was necessary (21 x using face masks, 2 x oral intubation). Pseudo-syndactyly (digits II - V, partially or totally) occurred in four hands after six to ten months. Flexion contractures of the digits occurred in two hands after eight to ten months. Limitating adduction contracture of the thumb occurred in two hands after eight to twelve months. Digital function (pinch and grasp) was actually preserved in two hands for 15 to 30 months. An active surgical approach is justified by the gain in functional improvement of the hand - even if only temporary - and, consecutively, by the positive effect on the child's development.

Bone Wires↗
PubMedDate not supplied

Teratogenic mechanisms of longitudinal deficiency and cleft hand.

In order to better understand the teratogenic mechanisms of congenital defects of the digits, we analyzed clinical cases and induced similar types of congenital hand anomalies in rat fetuses by oral administration of busulfan. In clinical cases, radial and ulnar deficiencies had common characteristic features. We induced radial and ulnar deficiencies in rat fetuses with the same drug. Radial and ulnar deficiencies induced in rats have similar clinical manifestations and these anomalies might be caused by the same teratogenic mechanism. Then, the formation of the digital rays was examined histologically. The results of histological examination suggested that these deficiencies were not caused by localized damage of the limb bud. They also suggested that the cause of missing digits in longitudinal deficiency is closely related to a deficit of mesenchymal cells in the limb bud. Cleft hand is considered to be one of the types of longitudinal deficiency. However, several investigators have suggested that the abnormal induction of finger rays in the process of formation of fingers induced central polydactyly, osseous syndactyly and also cleft hand. X-rays of the clinical cases and skeletal changes of the anomalies induced in rats appear to demonstrate that cleft hand formation proceeds from osseous syndactyly and central polydactyly. The results of our experimental study show that the critical periods of central polydactyly, osseous syndactyly and cleft hand are the same. They also suggest that central polydactyly, syndactyly and cleft hand might be induced when the same teratogenic factor acts on embryos at the same developmental stage in the human being. Because they have a similar causation, cleft hand, syndactyly and central polydactyly should be classified into the same entity, that is, abnormal induction of digital rays. Based on these clinical and experimental studies, we modified the Swanson classification. In our modified classification, typical cleft hand, syndactyly and polydactyly are included in the same category of abnormal induction of digital rays as the fourth new category.

Animals↗