Biomedical subjects

M Letts

Publications and source records attributed to M Letts.

At least 19 recordsLinked to original sources

PubMed2001

Patent foramen ovale and brain microembolization during scoliosis surgery in adolescents.

STUDY DESIGN: A case series is reported. OBJECTIVE: To improve understanding of the potential mechanisms associated with cerebral microemboli during scoliosis surgery in adolescents. SUMMARY OF BACKGROUND DATA: Paradoxical cerebral fat microembolization during scoliosis surgery has been associated with right-to-left shunting through an undetected patent foramen ovale. The prevalence of this cardiac defect in the adult population may be as high as 15% to 25%. Although the clinical relevance of this embolic phenomenon during scoliosis surgery has not been investigated, a few reports have documented its fatal consequences. It has been suspected in some patients with postoperative reduced visual function, particularly after complex instrumented fusions. METHODS: Bilateral transcranial Doppler (2 MHz) was used to monitor cerebral microemboli in the right and left middle cerebral arteries during spinal instrumentation and fusion in four patients. Additionally, transthoracic or transesophageal echocardiography incorporating pulse and color Doppler (3.5-5 MHz) and a contrast test was used in these patients to detect atrial shunts. RESULTS: Intraoperative transcranial Doppler monitoring detected high rates of cerebral microemboli associated with the presence of an atrial communication in two adolescents. In two additional patients with no detected brain microembolization, echocardiographic examination indicated the absence of an atrial shunt. CONCLUSION: The study findings suggest that unrecognized atrial communications in adolescents undergoing scoliosis surgery contribute to higher rates of Doppler-detected cerebral microemboli than those found in adolescents without this congenital defect.

Adolescent↗

PubMed2001

Effects of a tensioned tendon graft in a bone tunnel across the rabbit physis.

Children who sustain anterior cruciate disruption often are denied the standard reconstructive procedures because of the concern that drilling across the physis of the tibia and femur and compression from a tensioned graft will result in growth plate arrest. To test this concept and to assess whether a tendon placed in the tunnel would function in a manner similar to a fat graft after the resection of a physeal bar, tunnels were made across the proximal tibial physis and distal femoral physis in a group of immature rabbits. Four tunnel diameters were used from 1.95 to 3.97 mm, in three rabbits at each diameter, with patellar tendon autografts being used as the reconstruction of the anterior cruciate ligament in two of the animals. The knees were radiographed every 4 weeks, and the animals were euthanized 4 months after surgery. The surgically treated and control knees were salvaged, and each knee was examined grossly, radiographically, and histologically. Eight of the 11 animals had growth arrest of one or both physes. The larger the drill hole diameter the more marked was the deformity. The proximal tibial physis seemed to be the most vulnerable for growth arrest, occurring in eight of the knees. The insertion of a tendon did not seem to offer any protection to physeal arrest. Because of these findings, it is not recommended that tunnels involving 1% or more of the area of the physis be placed across the tibial and femoral physis to reconstruct the anterior cruciate in very skeletally immature children.

Animals↗

PubMed2001

An analysis of burst fractures of the spine in adolescents.

Burst fractures are less common in children than in adults because of the greater mobility and elasticity of the pediatric spine. Because of these spine characteristics, these fractures may behave differently in childhood than in adulthood. To try to address these differences, we reviewed our experience with 11 children (5 boys, 6 girls) treated for burst fractures. Average age at time of injury was 14.4 years. Follow-up averaged 9 years. All fractures were categorized using the Denis classification system for burst fractures. Three children had associated spinal cord injury. Five children were treated with nonoperative bedrest and casting; the other 6 children, who had the most severe burst fractures, were treated with posterior spinal fusion and instrumentation. Satisfactory functional results were found in 90% of the children at follow-up. Radiological evaluation at initial and follow-up examination showed that children treated operatively improved or maintained their fracture kyphosis (range, 12 degrees - 19 degrees). Anterior vertebral compression improved an average of 15% (range, 24%-39%). In the children treated nonoperatively, kyphosis progressed an average of 9 degrees (range, 15 degrees - 24 degrees), and anterior vertebral compression increased a further 8% (range, 36%-44%). Our results showed that (a) the children who sustained burst fractures tended to develop mild progressive angular deformity at the site of the fracture, (b) operative stabilization prevented further kyphotic deformity as well as decreased the length of hospitalization without contributing to further cord compromise, and (c) nonoperative treatment of burst fracture was a viable option in neurologically intact children, but progressive angular deformity occurred during the first year after the fracture.

Accidental Falls↗

PubMed2001

Analysis of the efficacy of pediatric day surgery.

OBJECTIVES: To assess the efficacy and safety of a pediatric day surgery program and its benefits to the child and family. DESIGN: A review and analysis of prospectively gathered data. SETTING: The Children's Hospital of Eastern Ontario (CHEO), a university-affiliated pediatric centre with a referral base of 2.5 million people. PATIENTS: All children undergoing day surgery at CHEO during the 5 years between 1992 and 1997. INTERVENTIONS: All surgical procedures performed on a day surgery basis. MAIN OUTCOME MEASURES: Procedures performed, complications and unexpected admissions. RESULTS: An average of 4,899 children per year underwent surgical procedures in the ambulatory day surgery program. The 4 commonest procedures performed were myringotomy, tonsillectomy and adenoidectomy, dental procedures, and inguinal hernia repair. The majority of children were between 2 and 7 years of age. Complications were few, averaging 1.6% per year, with postoperative bleeding, primarily secondary to tonsillectomy and adenoidectomy, being the most common. None resulted in permanent disability and there were no deaths. CONCLUSIONS: Pediatric day surgery is a safe and cost-effective program that benefits the child, the family and the pediatric surgical program.

Adolescent↗

PubMed2001

Differentiation of psoas muscle abscess from septic arthritis of the hip in children.

A 20-year review was conducted of children presenting with psoas abscess at two major pediatric hospitals. Eleven children with psoas abscesses were identified. The extreme variability in the clinical presentation of this condition is shown. Psoas abscess was most difficult to differentiate from septic arthritis of the hip in pediatric patients. This study also shows the often circuitous investigative route traversed before arriving at the diagnosis of psoas abscess. Atypical features, such as femoral nerve neurapraxia or bladder irritability in association with hip pain, should alert the clinician to consider psoas abscess. Based on this study, a diagnostic algorithm to differentiate between psoas abscess and septic hip was formulated.

Algorithms↗

PubMed2001

Trauma to the thoracic and lumbar spine in the adolescent.

During adolescence the spine undergoes rapid growth and changes in anatomy and biomechanical properties. Fractures of the adolescent spine are relatively uncommon but may give rise to serious problems. This review describes thoracolumbar fractures in adolescents with respect to epidemiology, anatomy, mechanisms of injury, clinical and radiologic assessment, and nonoperative and operative treatment. The treatment of these injuries follows many of the same principles as spinal fractures in adults but nonoperative treatment is used more frequently because there is less spinal instability and better tolerance of bed rest and spinal immobilization in this young population.

Adolescent↗

PubMed2001

Snowboarding injuries in children.

OBJECTIVE: To study injury patterns of snowboarding trauma in children. DESIGN: A retrospective case series. SETTING: A major pediatric trauma centre. PATIENTS: A cohort of 113 children (97 boys, 16 girls), mean age 13.9 years, who sustained 118 injuries secondary to snowboarding. INTERVENTIONS: All fractures were treated by immobilization in a cast; 19 children required a closed reduction. OUTCOME MEASURES: Sex and age of patients, mechanism of injury, injury sustained, treatments and complications. RESULTS: Falls on the outstretched hand from a loss of balance accounted for 66 (57%) of the injuries, uncontrolled falls for 42 (36%) and collisions for 5 (4%). Seventy-nine percent of the injuries were to the upper extremity, whereas 7% were to the lower extremity. CONCLUSIONS: The predominance of snowboarding injuries of the upper extremity seen in children differs significantly from those in adults in whom lower extremity injuries are more common.

Adolescent↗

PubMed2001

Children in crashes: mechanisms of injury and restraint systems.

OBJECTIVES: To explore the levels of protection offered to children involved in motor vehicle collisions. DESIGN: A joint study by the Children's Hospital of Eastern Ontario (CHEO) and Transport Canada, Ottawa, conducted in 2 phases: retrospective from 1990 to 1997 and prospective from 1998 to 2000. SETTING: CHEO, a university affiliated tertiary care centre. PATIENTS: Children admitted to CHEO between 1990 and 2000 with spinal trauma due to motor vehical crashes (MVCs). Phase I of the study involved analysis, in a series of 45 children after MVAs, by location of spinal injury versus belt type. Phase 2 was a prospective study of 22 children injured in 15 MVAs. INTERVENTIONS: A biomechanical assessment of the vehicle and its influence on the injuries sustained. MAIN OUTCOME MEASURES: The nature and extent of the injuries sustained, and the vehicle dynamics and associated occupant kinematics. RESULTS: The odds ratio of sustaining a spinal injury while wearing a 2-point belt versus a 3-point belt was 24 (95% confidence interval 2.0-2.45, p < 0.1), indicating a much higher incidence with a lap belt than a shoulder strap. CONCLUSIONS: Proper seat-belt restraint reduces the morbidity in children involved in MVCs. Children under the age of 12 years should not be front-seat passengers until the sensitivity of air bags has been improved. Three-point pediatric seat belts should be available for family automobiles to reduce childhood trauma in MVCs.

Accidents, Traffic↗

PubMed2000

An analysis of a preoperative pediatric autologous blood donation program.

OBJECTIVE: To determine the efficacy of a pediatric autologous blood donation program. DESIGN: A retrospective study of patient charts and blood-bank records. SETTING: The Children's Hospital of Eastern Ontario, Ottawa, a tertiary care, pediatric centre. PATIENTS: One hundred and seventy-three children who received blood transfusions for a total of 182 procedures between June 1987 and June 1997. INTERVENTIONS: Autologous and homologous blood transfusion required for major surgical intervention, primarily spinal fusion. MAIN OUTCOME MEASURES: Surgeons' accuracy in predicting the number of autologous blood units required for a given procedure, compliance rate (children's ability to donate the requested volume of blood), utilization rate of autologous units and rate of allogeneic transfusion. RESULTS: The surgeons' accuracy in predicting the number of autologous units required for a given procedure was 53.8%. The compliance rate of children to donate the requested amount of blood was 80.3%. In children below the standard age and weight criteria for blood donation the compliance rate was 75.5%. The utilization rate of autologous units obtained was 84.4% and the incidence of allogeneic transfusion was 26.6%. CONCLUSIONS: There was a high rate of compliance and utilization of predonated autologous blood in the children in the study. Preoperative blood donation programs are safe and effective in children, even in those below the standard age and weight criteria of 10 years and 40 kg.

Adolescent↗

PubMed2000

Subcutaneous granuloma annulare of the extremities in children.

OBJECTIVE: To familiarize surgeons to the natural history and treatment of granuloma annulare of the extremities in children. DESIGN: Case review and follow-up by appointment and questionnaire. SETTING: The Children's Hospital of Eastern Ontario, a tertiary referral centre. PATIENTS: Twenty-seven children (23 girls, 4 boys) seen between 1983 and 1998 with subcutaneous granuloma annulare, proven pathologically. The mean age at initial presentation was 8.3 years (range from 1.8 years to 16.7 years). The mean follow-up was 45 weeks (range from 1 week to 5 years). INTERVENTION: Biopsy excision of the lesions. OUTCOME MEASURES: The incidence multiple lesions, the commonest site of occurrence and the incidence of recurrence. RESULTS: Six children presented with multiple lesions for a total of 46 lesions. The anterior pretibial area was the most frequently affected site (16 lesions), followed by the ankle (6 lesions) and the long finger (4 lesions). Five patients suffered recurrence of the lesion, with a total of 7 lesions recurring. CONCLUSIONS: Subcutaneous granuloma annulare is a benign inflammatory skin lesion occurring most frequently in the anterior pretibial area in children, predominantly girls. The incidence of recurrence and of multiple lesions is high. Biopsy is required for definitive diagnosis. The lesion resolves spontaneously without treatment.

Adolescent↗

PubMed1999

The spinal manifestations of Stickler's syndrome.

STUDY DESIGN: A review of current knowledge, clinical publications, and recent concepts of the causes of Stickler's syndrome was correlated with a clinical review of the condition at the Children's Hospital of Eastern Ontario, Canada. OBJECTIVES: To acquaint orthopedic spine surgeons with the natural history, associated anomalies, and high incidence of spinal deformity and scoliosis in children with Stickler's syndrome. SUMMARY OF BACKGROUND DATA: Stickler's syndrome is a hereditary, progressive arthro-ophthalmopathy with an autosomal dominant inheritance pattern. The estimated incidence is 1 in 10,000 people, which is slightly more common than Marfan syndrome. METHODS: The experience with Stickler's syndrome was reviewed in seven children, 2-15 years of age, with particular attention to the spinal abnormalities secondary to the connective tissue dysplasia. RESULTS: Six of the children had kyphosis or scoliosis, and four had wedging or flattening of the vertebrae or platyspondylia. In general, the spinal changes became more prominent in the older children with Stickler's syndrome, with the spinal vertebrae affected by the generalized epiphyseal dysplasia. The treatment of scoliosis and kyphosis is no different in children with Stickler's syndrome. The most difficult aspect is in diagnosing the condition. CONCLUSIONS: The importance of recognizing the syndrome is to allow for the investigation and treatment of the many other associated connective tissue disorders associated with Stickler's syndrome, such as the high incidence of retinal detachment, mitral valve prolapse, and mandibular hypoplasia that may result in problems with anesthesia should the spine require surgical stabilization.

Adolescent↗

PubMed1999

Seat belt fracture with late development of an enterocolic fistula in a child. A case report.

STUDY DESIGN: A case report of a 9-year-old boy treated at a pediatric trauma center for a flexion-extension spiral fracture with late development of an enterocolic fistula subsequent to a high-velocity motor vehicle accident. OBJECTIVES: To increase the awareness of possible delayed bowel complications associated with flexion-distraction injuries of the spine in children. SUMMARY OF BACKGROUND DATA: Flexion-distraction fractures of the spine in children wearing lap seat belts, so-called "Chance" fractures, are an increasingly common result of high-velocity collisions. This type of fracture, referred to as a seat-belt fracture, is often associated with duodenal or jejunal tears. Although such intra-abdominal injuries are common in such fractures secondary to this type of trauma, the occurrence of an enterocolic fistula has never been reported. METHODS: A review of all pediatric Chance fractures managed at the Children's Hospital of Eastern Ontario, as well as a literature review of all reported series of flexion-distraction injuries to the spine in children, were performed. RESULTS: The subtle and prolonged symptomatology of this lesion and its similarity to a cast syndrome is emphasized. CONCLUSION: Because the orthopedic surgeon is usually the primary care-giver for children with this type of seat-belt trauma, an appreciation of the possibility of a delayed onset enterocolic fistula with its symptomatology is essential to avoid prolonged morbidity.

Accidents, Traffic↗

PubMed1999

The role of bilateral talectomy in the management of bilateral rigid clubfeet.

Severe clubfoot is a common sequela of arthrogryposis multiplex congenita and myelomeningocele. Talectomy is a practical surgical procedure to assist in the correction of severe, rigid equinovarus foot deformity. However, the results of talectomy may be less predictable in rigid bilateral equinovarus foot deformity than in the treatment of unilateral clubfoot. To determine the outcome of talectomy in the treatment of bilateral rigid clubfoot, we reviewed the cases of all patients at our center who underwent bilateral talectomy. Seven children were treated for bilateral talipes equinovarus with talectomy. The patient group consisted of 3 children with arthrogryposis, 3 with myelomeningocele, and 1 with Duchenne muscular dystrophy. The age at surgery averaged 6 years and ranged from 1 year and 10 months to 15 years and 7 months. The length of follow-up averaged 5 years and 6 months and ranged from 3 years to 12 years and 6 months. Three feet had a good and 7 feet a satisfactory correction of the deformity. Four feet had poor results. Bilateral talectomy was found overall to be a successful and predictable procedure, with low morbidity for the attainment of functional feet.

Adolescent↗

PubMed1999

Sickle cell disease of the spine in children.

OBJECTIVE: To determine the incidence of back pain in children admitted with sickle cell disease so as to increase awareness of this disease in black children presenting with back pain or discomfort. DESIGN: A retrospective review. SETTING: The Children's Hospital of Eastern Ontario in Ottawa, a tertiary care, university affiliated centre. PATIENTS: Thirty children were treated for active sickle cell disease between 1990 and 1996. Eleven (5 boys, 6 girls) suffered vascular-occlusive phenomena occurring in bone, referred to as "bony crises," requiring a total of 49 admissions. MAIN OUTCOME MEASURES: Clinical manifestations of spinal involvement by sickle cell disease. MAIN RESULTS: The spine represented the second most common area of bone involvement (26%) exceeded only by the knee (35%). The vertebral level affected was lumbosacral in 66% of cases, followed by thoracic in 22% and cervical in only 12%. Eighty-six percent of the children with spinal pain were anemic upon presentation, 71% had an elevated leukocyte count, 15% were hyponatremic and 15% were hyperkalemic. Minimal physical signs in the spine were noted, other than a local tenderness over the spinous process in 71% and a decreased range of back motion in 17%. CONCLUSIONS: Sickle cell disease is becoming more common in Canada as a result of increasing immigration from African countries and should always be considered as a possible cause of back pain in a black child.

Anemia, Sickle Cell↗

PubMed1999

Childhood rhabdomyosarcoma of the trunk and extremities.

Since 1979, 15 children with rhabdomyosarcoma have been treated at our institution. Included in this group are six children who presented with rhabdomyosarcoma of an extremity or trunk, requiring the use of combined multimodality therapy. The patients were clinically grouped and treated in accordance with the Intergroup Rhabdomyosarcoma Study protocol. All patients received combination chemotherapy based on their respective stage of disease at diagnosis. When feasible, the primary tumor was resected en bloc before chemotherapy was begun. After surgery, patients with unclear postoperative surgical margins and an initial good response to chemotherapy received radiotherapy to the primary site and at the regional lymphatics. Three of six patients developed or maintained a complete tumor response to induction chemotherapy. Radiotherapy maintained control of local disease in both groups. Overall, four patients, including one with disseminated disease at diagnosis, are alive, with a median survival time from diagnosis of 39 months. In children, treatment must be individualized, but complete local excision of the tumor with a tumor-free margin should be the goal. Major ablative amputation surgery was not performed.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1999

Symphalangism in children. Case report and review of the literature.

Symphalangism is an uncommon syndrome characterized by fusion of the interphalangeal joints of the hands and feet. The fusion can involve the proximal or the distal joints; however, involvement of the proximal interphalangeal joints is more common. Symphalangism often is associated with several other skeletal and nonskeletal abnormalities. Analysis of the pedigrees of affected families reveals this trait to be autosomal dominant. The authors present the case of a 9-year-old boy with bilateral symphalangism of the proximal interphalangeal joints in the fingers and toes. His father is affected similarly. A comparison of these cases with those published in the literature indicates that although the radiologic appearance of symphalangism appears disabling, the fused phalanges seldom cause disability or loss of function of the hand. Surgical intervention is not required in most patients. The father and son reported also had capitellar hypoplasia and subluxation of the radial head associated with limitation of elbow flexion and extension.

Adult↗

PubMed1998

The influence of desmopressin on blood loss during spinal fusion surgery in neuromuscular patients.

STUDY DESIGN: A double-blind study comparing the effects of desmopressin and a placebo (normal saline) on blood loss during spinal instrumentation for neuromuscular scoliosis. OBJECTIVE: To determine the effectiveness of desmopressin acetate (DDAVP) in reducing operative blood loss in hemostatically normal patients undergoing spinal fusion surgery for neuromuscular scoliosis. SUMMARY OF BACKGROUND DATA: Desmopressin acetate has been shown to improve bleeding times and to provide surgical hemostasis in patients with platelet disorders. Its effect in reducing bleeding times in normal patients has been the subject of debate in several surgical specialties. Recent observations that DDAVP seems to reduce bleeding times and blood loss in patients undergoing spinal surgery for neuromuscular scoliosis warranted a more focused analysis on its role in this surgical procedure. METHODS: Patients undergoing surgery for neuromuscular scoliosis were randomly assigned to receive DDAVP or placebo. Bleeding times and plasma clotting factors were measured before the administration of the DDAVP or placebo and 60 minutes after. Operative blood loss was carefully measured. RESULTS: Although the administration of DDAVP decreased overall blood loss by an average of 19% compared with blood loss in the placebo group and blood loss per vertebra fused by an average of 15%, these results were not statistically significant. CONCLUSIONS: Bleeding time and blood loss seem to respond better to DDAVP in some patients, in whom significant decreases were observed, than they do in others. The problem is in identifying those patients in whom a decrease in bleeding time will be elicited after administration of DDAVP. Preoperative administration of DDAVP to such patients should significantly decrease operative blood loss.

Adolescent↗

PubMed1998

Periosteal augmentation of the acetabulum.

The periosteum in children and especially infants has significant osteogenic potential. To determine the efficacy of periosteal flaps to assist in improving acetabular coverage in children with acetabular dysplasia, a series of experiments were designed using young rabbits. Three groups of five rabbits each had periosteal flaps fashioned and brought down from the anterolateral aspect of the innominate bone superior to the acetabulum and sutured to the capsule of the hip. The study was designed to examine the effects of the periosteal cambium layer in the formation of new bone to augment the acetabulum and to determine the effects of a periosteal flap plus cancellous bone graft. A control group of five rabbits underwent a sham operation of an open arthrotomy of the hip. Radiographic and histologic examination at 12 weeks revealed augmentation of the acetabulum with periosteal flaps that resulted in an average improvement of the acetabular index of 3.5 degrees and 6.6 degrees, without and with bone graft, respectively. New bone formation from the rim of the acetabulum averaged 3.9 mm with periosteal flaps alone and 4.6 mm with bone graft added. Periosteal augmentation of the acetabulum in conjunction with established procedures for augmenting acetabular coverage would appear to be a useful procedure for improving coverage of the femoral head in children with acetabular dysplasia.

Acetabulum↗