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Biomedical subjects

R M Letts

Publications and source records attributed to R M Letts.

At least 19 recordsLinked to original sources
PubMed1999

Musculoskeletal manifestations of the Antley-Bixler syndrome.

The Antley-Bixler syndrome is a rare disorder with many musculoskeletal anomalies that demand orthopedic assessment. The syndrome includes skeletal, craniofacial, and urogenital anomalies. The most common skeletal deformities are radiohumeral synostosis, craniosynostosis, multiple joint contractures, and arachnodactyly. Other orthopedic manifestations that may occur are femoral bowing, ulnar bowing, camptodactyly, synostoses of carpal and tarsal bones, clubfoot, vertebral body anomalies, perinatal fractures, and advanced skeletal age. The inheritance pattern is thought to be autosomal recessive. A patient with this syndrome is described, which is the 18th of 24 reports published in the world literature. This case is compared with the other reported cases.

Abnormalities, Multiple↗
PubMed1997

The management of spinal metastasis in children.

OBJECTIVE: To seek an optimal treatment plan from the results of treatment for metastatic disease of the spine in children. DESIGN: An 8-year retrospective study of children with metastatic disease of the spine. Imaging studies were reviewed and treatment modalities analysed. SETTING: The divisions of pediatric orthopedics and pediatric neurosurgery at the Children's Hospital of Eastern Ontario, Ottawa. PATIENTS: All children seen between April 1980 and December 1987 who had lesions metastatic to the spine by hematogenous or direct extension. There were 20 children (15 boys, 5 girls) with a mean age at the time of diagnosis of 9.5 years. Follow-up ranged from 2 weeks to 108 months. One child was lost to follow-up. INTERVENTIONS: Eleven children underwent laminectomy and decompression. Of the 14 neurologically compromised children, 5 received chemotherapy and radiotherapy and 9 received chemotherapy, radiotherapy and surgery. MAIN OUTCOME MEASURES: Type of metastatic lesion, vertebrae involved and response to therapy. RESULTS: Vertebrae involved with metastases were as follows: cervical (3), thoracic (5), lumbar (8) and multilevel (2). Meninges were involved in 2 cases. The most common causes of metastatic spinal involvement were neuroblastoma (4 cases) and astrocytoma (6 cases). Pathologic fractures occurred in 4 children and kyphoscoliosis in 4. Spinal cord paresis developed in 14 of the 20 children. Of the 6 children who survived from 48 to 108 months, 5 had tumours of neural origin, 4 being astrocytomas. Children with neuroblastoma or leukemic infiltration had a good initial response to chemotherapy. Five of the 6 surviving children had astrocytomas, and 5 were treated by surgical decompression. CONCLUSIONS: Metastatic disease of the spine in children secondary to astrocytoma should be treated aggressively, but from the experience gained from this study it is impossible to devise a rigid treatment plan for each type of metastatic tumour. The choice of chemotherapy, radiotherapy or surgery depends on the type of tumour, the age of the child and whether or not the spinal cord is compromised.

Adolescent↗
PubMed1990

Pediatric Chance fractures: association with intra-abdominal injuries and seatbelt use.

Seven cases of Chance fractures of the spine in children are presented, with their association to intra-abdominal injuries secondary to seatbelt use. A discussion and review of the literature suggest an increasing frequency of this particular injury with a high association given the clinical sign known as the "seatbelt sign." Also reviewed is the association of intra-abdominal injuries secondary to seatbelt restraints, and particular attention is paid to the concurrence of intra-abdominal injury with Chance fractures of the spine. The unique features of the pediatric anatomy in relation to the design of the adult seat restraint as it relates to the vertebral fracture and intra-abdominal injuries are noted. A review of the literature discusses the development of a classification for this flexion-distraction type of vertebral injury, and supports our experience of the increasing frequency of these particular injuries with increasing seatbelt use.

Abdominal Injuries↗
PubMed1989

Pediatric update #7. The orthopaedic manifestations of head injury in children.

The incidence of significant head injury has been estimated at 220/100,000 children. Over 90% of these will recover with little residual disability. The purpose of this study is to re-examine the small but significant percentage of head injured children with permanent total body involvement to identify patterns of deformity and temporal sequences and to develop preventive treatment regimens. Sixteen head injured children with residual spastic quadriplegia were examined. All exhibited musculoskeletal abnormalities. Hip adduction contractures were most common leading to hip subluxation in eight children, followed by pes equinus, scoliosis, pelvic obliquity, and knee flexion contracture. The average time to onset of permanent foot deformity was 11 months after head injury, for scoliosis an average of 22 months postinjury, and for hip subluxation an average of 31 months postinjury. Hamstring contractures occurred later, at an average of 37 months, but caused the most interference with good seating. The physical problems of the head injured child have some similarities to those of the child with cerebral palsy, but with distinct differences. An aggressive surgical approach to prevention and treatment of fixed deformity in these children is recommended at an early stage with postoperative orthotic management and stable seating in abduction.

Child↗
PubMed1987

1-Desamino-8-D-arginine vasopressin (desmopressin) decreases operative blood loss in patients having Harrington rod spinal fusion surgery. A randomized, double-blinded, controlled trial.

To evaluate the effect of 1-desamino-8-D-arginine vasopressin (desmopressin) on blood loss in surgery, we conducted a randomized, double-blind trial of the drug in 35 patients with normal hemostatic function who were having spinal fusion with Harrington rod instrumentation. Seventeen patients were designated to receive 10 micrograms/m2 of desmopressin, and 18, to receive a placebo. Preoperative testing showed that desmopressin increased factor VIII coagulant activity, von Willebrand antigen concentrations, glass bead platelet retention, and prothrombin consumption and decreased the partial thromboplastin and bleeding times (p less than or equal to 0.0003). During surgery, desmopressin reduced blood loss by 32.5% (547 mL; 95% confidence interval [CI], 19 to 1075; p = 0.015) and reduced the need for concentrated erythrocyte transfusions by 25.6% (0.86 units; 95% CI, 0.08 to 1.65; p = 0.022). After surgery, desmopressin reduced the duration of treatment with analgesic agents by 13.1% (34.0 hours; 95% CI, -5.2 to 72.7; p = 0.105), presumably by decreasing bleeding in the surgical wound. When adjusted for the origin of the scoliosis by two-way analysis of variance, this effect was even more evident (p = 0.014). Multiple regression analysis showed that the best three predictors of blood loss in surgery and transfusion requirements were the bleeding time, glass bead platelet retention, and the use of desmopressin.

Adolescent↗
PubMed1987

Computer corner #16. Computer as an aid in orthopaedic slide production.

The state of the art in the field of graphics presentation is increasing almost monthly. At the present time, however, there is the software capability to allow orthopaedic surgeons to become quite competent in the production of quality graphic material, especially the production of 35-mm slides of a quality that can be presented at any orthopaedic meeting for a modest cost and minimal production time.

Audiovisual Aids↗
PubMed1986

Computer corner #13. Computerized examinations in orthopaedics.

Computerized examinations can play an important role in the evaluation and education of trainees in orthopaedics. Several centers in the United States and Canada are currently using these, thus allowing an exchange of examination questions. Once a system is set up, only minimal involvement on the part of the instructor and office staff is required. All participants--trainees and instructors--can benefit from computerized examinations.

Computer-Assisted Instruction↗
PubMed1986

Computer corner #15. The AAOS: request for computer system proposal.

The Committee on Computer Science and Practice Management of the American Academy of Orthopaedic Surgeons has provided an excellent format to ensure a happy relationship between the vendor and the orthopaedic office using this package. Problems in communication and understanding between the vendor and the orthopaedic surgeon will undoubtedly be significantly reduced. How the system will work is the vendor's problem, but what you want it to do for you is your problem, and both of these issues are addressed in these questionnaires. It is recommended in the computer package that three vendor proposals be invited. Since the most frequent cause of computer problems is improper evaluation of what functions the computer system must perform in order to meet the needs of the orthopaedic office, this series of questionnaires is important. In addition to recommending this computer package, I would also emphasize that if at all possible--in spite of what may appear to be an excellent system on paper--try to visit an office in which the system has been in use over the past six to 12 months.

Humans↗
PubMed1983

Conversation in the operating theater as a cause of airborne bacterial contamination.

Using microspheres of human albumin sprayed on the face and in the nostrils under the facemask, we studied the role of conversation in contaminating the operating-room environment in addition to the microbial contamination of the air in an empty and in an occupied operating room. Conversation consistently increased the number of microspheres found in the simulated wound. The spatial relationship between the mask and the hood was important in reducing contamination. A complete hood overlapping the mask, with no gaps at the sides or bottom of the mask, was most efficient. The air contamination was increased by the presence of operating-room personnel and varied in different parts of the theater according to the density of traffic. We concluded that conversation contributes to airborne contamination in the operating theater but that contamination from this source can be lessened by wearing a face-mask that extends underneath an overlapping hood.

Air Microbiology↗
PubMed1982

The hidden adolescent ankle fracture.

Ankle injuries are common in adolescence, seldom initially seen by orthopaedists, and often treated primarily by emergency department personnel. It is often not appreciated that the distal tibial growth plate fuses in a mediolateral direction, leaving it open and vulnerable to growth plate injuries for a longer period during adolescence. Fractures of the lateral plafond of the tibia are often not appreciated due to overlap of the fibula. A review of the injuries at the Winnipeg Children's Hospital has revealed these are not as uncommon as often supposed. A 3 year experience yielded 26 patients with so-called "Tillaux fractures" of which 9 could be diagnosed only by the oblique view and 5 were initially missed. Knowledge of the anatomical behavior of the fusing tibial growth plate in the ankle-injured adolescent plus mandatory oblique views of the ankle in this age group should enable the casualty officer in a busy emergency department to bring this fracture out of hiding and make the diagnosis in every instance.

Adolescent↗
PubMed1981

Influence of spinal curvature on exercise capacity.

It is well recognized that scoliosis in excess of 65 degrees results in cardiorespiratory impairment. Lesser degrees of spinal curvature have been noted to have near normal respiratory function studies at rest. Because of the great cardiorespiratory reserve, decreases in function secondary to scoliosis may be masked in studies conducted at rest. To study this concept, an investigation of the work capacity of 38 adolescent children with varying degrees of adolescent idiopathic scoliosis was undertaken. The maximal oxygen capacity and endurance time was measured and compared with a group of normal controls. A significant negative correlation between percentile endurance time and degree of spinal curvature was found showing a reduction in endurance time with every 20 degrees increase in spinal curvature (p less than 0.006). The application of "the exercise capacity test" as an investigative tool for scoliosis was found to be practical, since endurance time is a reliable index of the cardio-pulmonary status.

Adolescent↗
PubMed1980

Fractures of the neck of the talus in children.

A review of children with talar injuries treated at the Winnipeg Children's Hospital yielded 12 patients that had been treated for fractures of the neck of the talus between 1960 and 1978, inclusive. Three developed avascular necrosis of the body of the talus; two of these had their fractures recognized only after avascular necrosis had become radiologically evident. The children ranged in age from 1 year 7 months to 13 years 11 months at the time of the injury. Fracture of the neck of the talus does occur in children and may be associated with avascular necrosis of the body. This injury should be considered and the talus should be examined in all children sustaining trauma secondary to falls from a height or motor vehicle trauma.

Adolescent↗
PubMed1978

Auger injuries in children.

A 6-year review of auger injuries in Manitoba children revealed that 23 children sustained major injuries resulting in amputation of 17 limbs. Auger injuries are the main cause of traumatic amputation in children in Manitoba. Improved safety education for the entire farm family as well as better design of safety shields would decrease this carnage.

Agriculture↗
PubMed1978

Skeletal diseases associated with angiomatosis.

Basically, there are two conditions in which angiomatosis is associated with underlying skeletal disease. The first is Maffucci's syndrome in which angiomatosis is associated with multiple enchondromatosis. Two patients with this disease are presented and its clinical and radiologic features are reviewed. The second is "congenital angiectatic hypertrophy" in which angiomatosis is associated with localized hypertrophy of underlying bones, soft tissues and occasionally internal vercera. Four patients with this condition are presented, illustrating the subtypes of closely related diseases within a broad spectrum.

Angiomatosis↗
PubMed1978

The assessment of the internal rotation gait in cerebral palsy: an electromyographic gait analysis.

A study of 12 cerebral palsied children with internal rotation revealed three patterns of electromyographic activity: (1) Diagnostic pattern--where a simple muscle group stood out as the responsible agent--notably the medial hamstrings; (2) Nondiagnostic pattern--nonrecurring pattern; (3) Nondiagnostic pattern--recurring "mass limb reflex" pattern. In all cases, electromyography was useful for: (1) confirmation of clinical impressions. Electromyographic confirmation of phasic hamstring overactivity gives a firm basis for tendon surgery with expectancy of good results. (2) Detection of the responsible muscle group where clinical methods fail to do so. It detects the "at risk" patients, where follow up with tendon surgery at the appropriate time could be performed with predictable results. (3) Selection of patients who are likely to respond to tendon surgery, and those unlikely to benefit from it. The adductors and internal rotators may play only a secondary role in children whose predominant problem is internal rotation during gait. The medial hamstrings stand out as the most important single muscle group causing this problem. Consequently, it is important to analyze gait problems with the patient walking, and examine electromyographs during walking in the overall assessment of a patient with dynamic gait problem.

Adolescent↗
PubMed1978

Epiphysiolysis as a method of limb lengthening.

Epiphysiolysis followed by distraction was performed at the proximal tibial growth plates in 18 young rabbits. Union across the distracted plate occurred in all animals. In 12 rabbits skeletally immature at operation, premature fusion of the separated plate resulted in growth arrest of the operated limb. The contralateral control limb was longer at maturity by an average 1.10 cm. In 6 rabbits near skeletal maturity at epiphysiolysis, the operated limb was the longer at maturity by the amount distracted, an average of 0.62 cm. In all animals a permanent loss of joint motion resulted. Epiphyseal distraction in the very young rabbit does not appear to be practical due to consistent premature fusion of the distracted growth plate. It is possible to lengthen the limbs of rabbits near skeletal maturity with this procedure. An added advantage is that union between the epiphysis and the metaphysis always occurred, eliminated the problem of delayed ana non union found in diaphyseal lengthening. However, at this time, until the effects of distraction and compression on the adjacent joint can be minimized, epiphysiolysis as a method of limb lengthening is not recommended in children.

Age Factors↗