PubMed Health⌕ Search

Biomedical subjects

R C Henderson

Publications and source records attributed to R C Henderson.

47 records · Page 3Linked to original sources
PubMedDate not supplied

Longitudinal evaluation of bone mineral density in children receiving chemotherapy.

PURPOSE: Some children who survive a childhood malignancy have diminished bone mineral density (BMD). The purpose of this study is to assess when, and perhaps why, this problem develops. PATIENTS AND METHODS: BMD was longitudinally monitored in 37 children for a minimum of 1 year (mean, 23.4 months; range, 12 to 41 months) during and, in some cases, after chemotherapy. Evaluations included serum analyses (vitamin D, calcium, and alkaline phosphatase), assessment of calcium intake, and measures of growth and nutrition (height, weight, and skinfolds). RESULTS: BMD was already diminished at the start of treatment in some patients; 6 of 13 patients (46%) had a BMD z score in the hip or spine of < -1.0. However, only 1 patient (8%) was < -2.0. Most patients did not have a significant drop in BMD z scores during chemotherapy, but one in four did decrease at least 0.5 standard deviations. Age greater than 10 years, a drop in height z score, and treatment with cranial irradiation correlated with a drop in BMD z scores during treatment. In the year immediately after completion of chemotherapy, no consistent "catch-up" was observed in BMD z scores. CONCLUSIONS: In some patients, BMD z scores are diminished at the time of diagnosis and a drop may occur during treatment in others. Multiple factors related to the disease process and treatment likely contribute to these observations. Cranial irradiation, perhaps by impacting on growth hormone homeostasis, is one such factor. Fortunately, most survivors of a childhood malignancy will not have large deficits in BMD later in life.

Adolescent↗
PubMedDate not supplied

Evaluation of magnetic resonance imaging in Legg-Perthes disease: a prospective, blinded study.

Twenty-two patients (24 hips) with Legg-Perthes disease received 49 magnetic resonance (MRI) scans. The scans and corresponding radiographs were independently evaluated in a blinded fashion to assess the capabilities of, and indications for, MRI in Legg-Perthes disease. Early in the disease process, MRI often more clearly delineated the extent and location of areas of involvement than did plain radiographs. In one patient, MRI failed to indicate necrosis early in the course of the disease, but it was detected on plain radiographs. MRI can also be used to give a rough estimate of sphericity, which in some phases of the disease process is better than plain radiographs. For serially following the disease process through the natural healing course, plain radiographs were as good or better than MRI and considerably less costly.

Adolescent↗
PubMedDate not supplied

Etiology of late-onset tibia vara: is varus alignment a prerequisite?

One widely held theory on the pathogenesis of adolescent late-onset tibia vara is that obesity coupled with mild preexisting varus alignment produces forces sufficient to retard growth in the medial portion of the proximal tibial physis and initiates the development of the condition. Two cases are presented in which neutral mechanical alignment was clearly documented in an extremity that subsequently developed adolescent late-onset tibia vara within 19 months. We conclude that in at least some cases, preexisting varus alignment is not a prerequisite for the development of adolescent late-onset tibia vara.

Adolescent↗
PubMedDate not supplied

Postarthroscopy analgesia with bupivacaine. A prospective, randomized, blinded evaluation.

The analgesic effect of intraarticular bupivacaine injected at the conclusion of knee arthroscopy done under general anesthesia was investigated in a prospective, randomized, and blinded fashion. Pain scores, the use of analgesic medications, crutch use, weight-bearing, activity level, and difficulty sleeping the night after surgery were all unaffected by the use of bupivacaine. The apparent lack of effect is most likely due to rapid clearance from the knee, leaving only a transient, 1 to 2 hours of potential benefit. In this study, the patients were already quite comfortable during this time period due to the routine use of intraoperative narcotics. The preoperative level of knee discomfort was found to be a major determinant of postoperative discomfort. Other much less important factors were synovial and chondral shaving, sex of the patient, and experience of the surgeon.

Adult↗
PubMedDate not supplied

An evaluation of pre- and postoperative nonsteroidal antiinflammatory drugs in patients undergoing knee arthroscopy. A prospective, randomized, double-blinded study.

The potential benefits of a nonsteroidal antiinflammatory drug to 67 patients undergoing knee arthroscopy were evaluated in a prospective, randomized, placebo-controlled, double-blinded study. Group A received the drug (diclofenac, 75 mg twice daily) for 3 to 5 days before and for 7 days after surgery. Group B received a placebo preoperatively and the drug postoperatively. Group C received a placebo at both times. Codeine was available postoperatively for all patients if needed. Outcomes reported by the subjects included pain, crutch use, and return to activities. Outcomes assessed by physicians included knee effusion, range of motion, and gait. Knee flexion and extension strengths were measured isokinetically pre- and postoperatively. Pain scores on the 1st postoperative day were higher in Group C than in Group A. Pain scores at all other time points were not significantly different in the three treatment groups. Groups A and B required less codeine during the first 72 hours after surgery than Group C (mean, 2.9 +/- 1.0 versus 6.8 +/- 1.0 pills). Recovery of function, recovery of strength, and physical examination parameters were not significantly different in the three treatment groups. Diclofenac was an effective analgesic in the immediate postoperative period. Recovery from arthroscopy, however, was not enhanced by taking the drug.

Adolescent↗
PubMedDate not supplied

Bone mineral density and fractures in boys with Duchenne muscular dystrophy.

The relationships between bone density, mobility, and fractures were assessed in 41 boys with Duchenne muscular dystrophy. Bone density in the lumbar spine was only slightly decreased while the boys were ambulatory (mean z-score, -0.8), but significantly decreased with loss of ambulation (mean z-score, -1.7). In contrast, bone density in the proximal femur was profoundly diminished even when gait was minimally affected (mean z-score, -1.6), and then progressively decreased to nearly 4 standard deviations below age-matched normals (mean z-score, -3.9). These are consistent with the findings that 18 (44%) of the boys sustained a fracture, 66% of these fractures involved the lower extremities, and there were no spinal compression fractures. Furthermore, four (44%) of nine boys who were walking with aids or support at the time of fracture never resumed walking after the fracture. Osteoporosis is most profound in the lower extremities of boys with Duchenne muscular dystrophy, and begins to develop early while still ambulating. Frequent fractures that may result in loss of ambulation are the clinical consequences.

Adolescent↗
PubMedDate not supplied

Assessment of bone mineral content in children.

Quantitative digital radiography (QDR) is a new technique for measuring bone mineral content that offers improved precision, shorter study times, and less radiation exposure than single-photon absorptiometry (SPA), dual-photon absorptiometry (DPA), and quantitative computed tomography (CT) scanning. To evaluate application of QDR to a pediatric population, the bone mineral density (BMD) of both proximal femurs and lumbar spine was determined in 20 normal children aged 4-15 years. Duplicate measures indicated a precision less than 2%. A small left side/right side difference was sometimes found in the BMD of the proximal femurs. This difference was not related to age, sex, or handedness, and there was no history of significant injury to, or problems with, either lower extremity. QDR will greatly enhance early evaluation and treatment of many conditions that adversely affect the immature skeleton.

Adolescent↗
PubMedDate not supplied

Variability in radiographic measurement of bowleg deformity in children.

The tibial metaphyseal-diaphyseal (MD) and tibial-femoral (TF) angles were measured on the radiographs of 33 knees in young children (aged 12-36 months) with bowleg deformity. Four observers of differing experience measured the films in a blinded fashion to determine the intraobserver and interobserver variability of these measurements. The clinical implications of these variabilities are described. Very little instruction and experience is necessary to make these measurements correctly and precisely. Measurement of the MD angle was superior to measurement of the TF angle. Contrary to published opinion, rotation can have a small but potentially significant effect on the measured MD angle.

Anthropometry↗
PubMedDate not supplied

Magnetic resonance evaluation of "metaphyseal" changes in Legg-Calvé-Perthes disease.

Twenty involved hips in 16 patients with Legg-Calvé-Perthes disease (LCP) were studied with both plain radiographs and magnetic resonance imaging (MRI) scans to better evaluate the existence of "metaphyseal" changes. Thirty-four sets of radiographs and MRI scans were reviewed in a blinded fashion and compared for the presence and location of these changes. Of 23 hips with plain radiographic metaphyseal changes, 11 showed no such changes on MRI scans (48%). Twelve hips did show MRI changes located in the anterior metaphysis. One hip studied three times had a discrete cystic change located in the central metaphysis. Of 11 hips with no plain radiographic changes in the metaphysis, five showed metaphyseal changes on MRI. Metaphyseal changes in LCP remain poorly understood. Even with use of MRI, fine distinction between physis and metaphysis still proved difficult. It appears that most metaphyseal changes are physeal and epiphyseal irregularities. A few hips have truly metaphyseal lesions. The significance of these "cysts" is unclear.

Child↗
PubMedDate not supplied

Prevalence of late-onset tibia vara.

We wished to determine the prevalence of late-onset tibia vara in an at-risk population. From a group of 1,117 boys aged 13-19 years, we selected all those who weighed at least 210 pounds. The 140 boys (80 black, 60 white) who met this inclusion criterion were examined for varus alignment. Radiographs of the seven boys who screened positive showed that two boys had late-onset tibia vara. Both boys were black and weighed > 280 pounds. The prevalence of late-onset tibia vara in this obese adolescent black male population was 2.5% (two of 80 boys). Recently, the number of reported cases of late-onset tibia vara has increased dramatically probably owing to an increase in the prevalence of morbid obesity.

Adolescent↗