Age-related osteoporosis in Chinese: an evaluation of the response of intestinal calcium absorption and calcitropic hormones to dietary calcium deprivation

BACKGROUND

Age-related osteoporosis may be associated with inefficient intestinal calcium absorption and bone remodeling.

OBJECTIVE

We investigated the pathogenesis of age-related osteoporosis in Chinese women with habitual low calcium intakes.

DESIGN

We studied the response of intestinal calcium absorption, calcitropic hormones, and biochemical bone markers to graded dietary calcium deprivation.

RESULTS

The osteoporotic subjects (n = 25) had higher urinary calcium excretion (P < 0.05) and lower plasma 1,25-dihydroxyvitamin D concentrations (P < 0.02) than did age-matched control women (n = 25). Parathyroid hormone was not significantly different from that in age-matched control women but was significantly higher than in young women (n = 15, P < 0.05). Fractional 45Ca absorption was approximately 61% in all 3 groups when the diet was unmodified and increased to 71%, 69%, and 68% in the osteoporotic subjects, age-matched control women, and young women, respectively, when dietary calcium was reduced to 300 mg/d. When the osteoporotic women were calcium deprived, serum 1,25-dihydroxyvitamin D failed to increase but urinary calcium excretion persisted. In contrast, supplementation with 1200 mg Ca resulted in a lowering of parathyroid hormone (P < 0.005 compared with the unmodified diet) and 1,25-dihydroxyvitamin D (P < 0.01) and decreased fractional 45Ca absorption (P < 0.01), suggesting that the increased calcium intake was associated with a potent compensatory ability of the intestine and calcitropic hormones to adapt. Calcium supplementation lowered osteocalcin (P < 0.05) but not alkaline phosphatase, which remained elevated in the osteoporotic subjects at all stages.

CONCLUSIONS

Elderly osteoporotic women had reduced 1,25-dihydroxyvitamin D production, excessive urinary calcium loss, and high bone turnover. The Chinese women had exceptionally potent intestinal calcium absorption.

Assessment of scoliosis correction in relation to flexibility using the fulcrum bending correction index

STUDY DESIGN

A prospective study on adolescent idiopathic scoliosis to assess a new method of describing frontal plane correction.

OBJECTIVE

To assess the difference between using the correction rate and using the new fulcrum bending correction index when describing scoliosis correction.

SUMMARY OF BACKGROUND DATA

A description of the outcome of scoliosis surgery based on the correction rate does not take into account the curve's flexibility.

METHODS

The fulcrum bending correction index is calculated by dividing the correction rate by the fulcrum flexibility (based on the fulcrum bending radiograph) and is expressed as a percentage. The fulcrum bending correction index was compared with the correction rate in 35 patients with adolescent idiopathic scoliosis undergoing surgical correction. These patients were divided into a stiff and a flexible group based on a fulcrum flexibility of 50% to show the advantage of the fulcrum bending correction index over the correction rate.

RESULTS

The difference in correction rate between the flexible (66%) and the stiff group (45%) was significant (P < 0.05). The difference in the fulcrum bending correction index between the flexible (96%) and the stiff group (107%) was not significant (P = 0.2).

CONCLUSIONS

The fulcrum bending correction index takes into account the curve flexibility and is therefore better than the correction rate for comparing curve correction and use of instrumentation systems between different series of patients. A fulcrum bending correction index of close to 100% suggests that the instrumentation has taken up all the flexibility revealed by the fulcrum bending radiograph. It is recommended that the fulcrum bending correction index be used in the future as part of the postoperative assessment of frontal plane correction in cases of thoracic scoliosis.

Costal osteochondroma. A rare cause of spinal cord compression

STUDY DESIGN

Report of a rare cause of spinal cord compression: costal osteochondroma.

OBJECTIVE

To describe a very rare cause of spinal cord compression, costal osteochondroma, which was present in a 16-year-old girl with a history of hereditary multiple exostoses.

SUMMARY OF BACKGROUND DATA

Only four cases of expansion of costal osteochondroma into the spinal canal through an intervertebral foramen have been reported previously.

METHODS AND RESULTS

The origin of the osteochondroma at the head of the right 12th rib, the invasion of the spinal canal through the right T12-L1 intervertebral foramen, and the compression of the spinal cord were shown on computed tomography and magnetic resonance imaging. The exact extent of the osteochondroma, particularly the cartilage cap, was delineated accurately by magnetic resonance imaging. Complete excision followed by full recovery occurred 19 months after surgery.

CONCLUSION

Magnetic resonance imaging is the preferred method of investigation in cases of osteochondroma related to spine, because it allows for better pre-operative planning and helps to prevent incomplete excision of the tumor.

Radiographic assessment of pedicle hook placement

STUDY DESIGN

A cadaveric study of the changes in the radiographic morphology of the thoracic pedicle with vertebral rotation.

OBJECTIVE

To study the effect of vertebral rotation on the assessment of pedicle hook placement by determining the radiographic anatomy of the pedicle and its relation to the pedicle hook.

SUMMARY OF BACKGROUND DATA

It is commonly assumed that the oval pedicle shadow seen on spine radiographs is formed by the waist of the pedicle. The postoperative assessment of pedicle hook position is based on this assumption.

METHODS

Thoracic cadaveric vertebrae between T5 and T8 were studied, with wire markers placed at the waist, the pedicle-facet junction, and the pedicle-body junction. Thoracic pedicle hooks were placed in the correct position and offset to one side. Radiographs of the vertebral body were taken from 0 degree to 30 degrees of rotation with reference to the sagittal plane.

RESULTS

The radiographic morphology of the pedicle changes with vertebral rotation; it also differs between the concave and the convex side of a scoliotic spine. With rotation of less than 20 degrees, the pedicle shadow is formed by the waist on both sides. With 30 degrees of rotation, the concave pedicle shadow is formed by the pedicle-facet junction, whereas on the convex side, it is over-lapped by the transverse process shadow. A laterally misplaced hook on the convex side and a medially misplaced hook on the concave side can appear correctly located with vertebral rotation.

CONCLUSION

The oval pedicle shadow is not simply represented by the waist of the pedicle. An understanding of the changes in radiographic morphology with rotation is necessary for the assessment of thoracic pedicle hook location after surgery.

Prediction of correction of scoliosis with use of the fulcrum bending radiograph

We used a new method to assess spinal flexibility in thirty patients who were to be managed operatively for adolescent idiopathic scoliosis. The method involves placing the patient in the lateral decubitus position and bent over a fulcrum (a radiolucent padded cylinder) so that the spine is passively hinged open. For thoracic curves the fulcrum is centered under the rib corresponding to the apex of the curve, and for lumbar curves the fulcrum is placed directly under the apex. The preoperative workup for the thirty patients included an anteroposterior radiograph made with the patient standing, a lateral-bending radiograph made with the patient supine, and the new fulcrum bending radiograph. All patients were treated with posterior spinal arthrodesis with segmental spinal instrumentation. The degree of flexibility obtained with the traditional and new methods was compared with the degree of correction observed on the radiograph made, with the patient standing, one week after the operation. Preoperatively, the mean Cobb angle was 58 degrees on the anteroposterior radiograph made with the patient standing, 31 degrees on the lateral-bending radiograph made with the patient supine, and 24 degrees on the fulcrum bending radiograph. The mean angle was 25 degrees on the anteroposterior radiograph made one week postoperatively, so the mean correction was 57 per cent. The difference between the mean angle on the lateral-bending radiograph and that on the postoperative radiograph was significant (p < 0.001); however, the mean angle measured on the preoperative fulcrum bending radiograph and the postoperative angle were almost identical. We found the fulcrum bending radiograph to be more predictive of the degree of flexibility and correctability than the lateral-bending radiograph in this group of patients who had segmental spinal instrumentation for correction of idiopathic scoliosis.

Intervertebral disc autografting in a bipedal animal model

Fusion of the spine while restoring stability of the spinal segment, fails to preserve spinal mobility. Long term complications of accelerated degeneration in the neighboring segments have been reported. The present study explores the possibility of intervertebral disc autografting in a bipedal animal model by isolating a lumbar disc together with the adjacent end plates and repositioning it with minimal internal fixation. Fourteen Rhesus monkeys were sacrificed at 2, 4, 6, and 12 months after surgery and the grafted discs were examined radiologically, biochemically, pathologically, and biomechanically. Healing of the bony end plate was seen between 2 to 4 months postoperatively. There was early loss of disc height at 2 and 4 months but there was a suggestion of some reconstitution up to 12 months. There was minimal evidence of gross degeneration at all stages. Gradual loss of water content was found in the annulus and the nucleus. The nucleus pulposus seemed to be able to reaccumulate proteoglycan after an initial drop in the first 4 months. There was significant increase in hydroxyproline content in the annulus fibrosus and the nucleus pulposus. Biomechanically, the grafted disc showed hypermobility in the first 4 months but gradually became stabilized with time. Results from this study suggested that a fresh intervertebral disc autograft could survive a period of ischemia. Although the physiology of the disc was deranged, it was able to preserve a certain degree of segmental mobility without sacrificing stability. Further studies are required to validate these results and the field of disc allografting should be explored.

Applications of bone scintigraphy in ankylosing spondylitis

Eighteen bone scintisans performed in 14 patients with ankylosing spondylitis were reviewed. In young patients with low back pain, positive serology, and indeterminate radiographs, quantitative sacroiliac joint assessment and the presence of typical uptake patterns, particularly costovertebral, were useful in suggesting the diagnosis. Scintigraphy was helpful in the early detection of pseudoarthrosis complicating long-standing disease, especially in patients presenting with recurrent back pain. Selective application of bone scintigraphy aids the diagnosis of ankylosing spondylitis and its potential complications.

Spinal stenosis above a healed tuberculous kyphosis. A case report

STUDY DESIGN

This case report illustrates two patients with paraplegia of late onset resulting from cord compression in the hyperlordotic thoracic or thoracolumbar spine proximal to a healed tuberculous kyphosis.

OBJECTIVES

The objective of this paper is to highlight that degenerative stenosis of the thoracic spine proximal to a healed stable kyphosis can be a cause of paraplegia of healed disease.

SUMMARY OF BACKGROUND DATA

Paraplegia resulting from tuberculosis of the spine can be of early or late onset. Early onset paraplegia is usually a result of cord compression by active disease. Late onset paraplegia can be due to disease reactivation, bony ridge compression, or unstable kyphosis. To our knowledge, compression of the cord proximal to a healed, stable kyphosis giving rise to paraplegia has never been reported.

METHODS

Patient 1 presented with symptoms of spinal claudication and progressive paraparesis. He was found to have spinal stenosis in the hyperlordotic thoracolumbar spine proximal to a healed lumbosacral tuberculous kyphosis. Patient 2 presented with a 2-year history of progressive paraplegia. Imaging revealed cord compression at the hyperlordotic T10-11 segment by disc protrusion, and facet hypertrophy.

RESULTS

Laminectomy successfully relieved the first patient of all symptoms but the second patient had significant deterioration of the neurologic status after surgery.

CONCLUSION

Compensatory hyperlordosis of the thoracic or thoracolumbar spine commonly occurs in patients with severe tuberculous thoracolumbar or lumbosacral kyphosis. Degenerative spinal stenosis and cord compression at such hyperlordotic segment can cause late onset paraplegia. The blood supply of these chronically compressed cords is precarious and the risk of surgery is high.

Effects of short anterior lumbar interbody fusion on biomechanics of neighboring unfused segments

STUDY DESIGN

Segmental mobility and intradiscal pressure were measured and the data compared in six cadaveric lumbar spine specimens before and after in vitro simulated single level L4-5 and double level L4-5-S1 anterior interbody fusions.

OBJECTIVE

The experimental objective was to study the biomechanical effects of single level L4-5 and double level L4-5-S1 anterior interbody fusions on the neighboring unfused segments.

SUMMARY OF BACKGROUND DATA

The relationship between the local rigidity created by fusion mass and accelerated degeneration reported at the neighboring unfused intervertebral discs is not clear.

METHODS

Six cadaveric lumbar spine specimens were biomechanically tested in flexion and extension. Segmental mobility and intradiscal pressure of the specimens were measured before and after in vitro simulation of single level L4-5 and double level L4-5-S1 anterior interbody fusions.

RESULTS

The mobility of the motion segments immediately above and below an L4-5 fusion was increased in flexion. When the L5-S1 segment was also fused, the loss of segmental motion in both flexion and extension at the L4-5 and L5-S1 were compensated for by increased motion in all levels above the fusion. In both flexion and extension, the intradiscal pressures of all unfused intervertebral discs were increased after a single level L4-5 fusion and this increase was even more marked after a double level L4-5-S1 fusion.

CONCLUSIONS

There is no evidence that the neighboring unfused segments are loaded beyond their physiological limits due to the fusion. However, the neighboring unfused segments have to work more frequently toward the extremes of their functional ranges of motion after fusion and these effects will be more marked after a double level L4-5-S1 fusion.

A 68-year-old man with gradual onset of low-back pain

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to orthopedic surgeons. The initial history, physical findings, and roentgenographic examinations are noted on this page. The clinical and roentgenographic diagnoses are presented on the following pages.

Relation of spinal and thoracic cage deformities and their flexibilities with altered pulmonary functions in adolescent idiopathic scoliosis

STUDY DESIGN

Seventy patients (average age, 13.8 years) with adolescent idiopathic right thoracic scoliosis had full assessment of pulmonary functions and radiographic evaluation of spinal and thoracic cage deformities and their flexibilities.

OBJECTIVES

To determine how measurements of spinal and thoracic cage deformities related to pulmonary function.

SUMMARY OF BACKGROUND DATA

Pulmonary functions have been evaluated in relation to lateral curvature of the spine in most of the published studies. Scoliosis is a three-dimensional deformity. There is a need to evaluate these changes in pulmonary functions, reflecting not only spinal curvature but also rotational deformity, thoracic cage deformity, and their flexibilities.

METHODS

Radiographic measurements obtained from anteroposterior and lateral standing and anteroposterior supine bending radiographs included lateral curvature, vertebral rotation, kyphosis, maximum sternovertebral distance, and apical rib-vertebral angles. Using previous measurements, the flexibility of the curve, vertebral rotation, and rib-vertebral angle were calculated. A pulmonary function assessment was performed using a computerized pulmonary function system (5000V; Gould, Dayton, Ohio). We analyzed pulmonary functions in relation to deformity.

RESULTS

Measurements reflecting spinal deformities obtained from anteroposterior radiographs, such as Cobb angle, vertebral rotation, and vertebral rotation flexibility, were significantly correlated with the percent of predicted values of vital capacity and forced vital capacity, whereas kyphosis measured from lateral radiographs was significantly correlated with absolute values of residual volume, total lung capacity, functional residual capacity, and forced expiratory flow from 25-75% of the forced vital capacity (FEF25-75). Of the measurements reflecting thoracic cage deformity obtained from anteroposterior radiographs, rib-vertebral angle asymmetry (measured from supine bending radiographs) showed significant correlation with the percent of predicted values of vital capacity, forced vital capacity, and functional residual capacity, whereas the sternovertebral distance that was measured from lateral radiographs correlated significantly with absolute values of vital capacity, total lung capacity, forced vital capacity, and FEF25-75.

CONCLUSIONS

Deformities in coronal and transverse plane influence changes in pulmonary functions expressed as the percent of predicted values, whereas sagittal plane deformities influence mainly those absolute volumes in which residual volume is a component. It is suggested that rotational flexibility combined with other deformities could be evaluated in future studies on prediction of pulmonary function from the measurements of the deformity.

Evaluation of deformities and pulmonary function in adolescent idiopathic right thoracic scoliosis

Seventy patients with adolescent idiopathic right thoracic scoliosis had full assessment of their pulmonary function using a computerised pulmonary function system. Their mean age at evaluation was 13.8 years. The following measurements were obtained from anteroposterior and lateral standing and antero-posterior supine bending radiographs: lateral curvature, vertebral rotation, kyphosis, maximum sterno-vertebral distance and apical rib-vertebral angles. Using the above measurements, the flexibility of curve, vertebral rotation and rib-vertebral angle asymmetry were calculated. Patients were classified into three groups on the basis of their predicted vital capacity, to determine whether radiological features of deformity can help identify patients with compromised pulmonary function. The mean Cobb angle and vertebral rotation for the 70 patients were 50 degrees (range 35-100 degrees) and 22 degrees (range 1-44 degrees) respectively. The mean flexibility of curve and vertebral rotation were 52% and 49% respectively. Mean thoracic kyphosis was 25 degrees, ranging from -7 to 55 degrees. Of the patients with Cobb angle less than 90 degrees, 71% had vital capacity less than 80% of predicted values, and of these, 18% had marked compromise of vital capacity (less than 60% of predicted values). Mean values of Cobb angle, vertebral rotational flexibility, kyphosis, rib-vertebral angle asymmetry (in standing as well as supine bending radiographs) differed significantly between patients with more than 80% of predicted vital capacity and those with 60% or less of predicted values. Radiological features indicative of better pulmonary function were: rotational flexibility exceeding 55%, rib-vertebral angle asymmetry (standing) less than 25 degrees and kyphosis greater than 15 degrees. Two deformity parameters--that give a better prediction of pulmonary function than the widely used Cobb angle, vertebral rotational flexibility and rib-vertebral angle asymmetry--were identified in this study.

Cord compression caused by multiple disc herniations and intraspinal cyst in Scheuermann's disease

STUDY DESIGN

The design for this article is a case report.

OBJECTIVES

Reported is the case of a patient with Scheuermann's disease who experienced spastic paraparesis caused by multilevel disc herniations and intraspinal meningeal cyst occurring together.

SUMMARY OF BACKGROUND DATA

Although Scheuermann's disease is associated with disc degeneration and calcification, multilevel disc herniations causing neurologic deficit is exceedingly rare.

METHODS

A patient diagnosed with Scheuermann's disease was evaluated by laboratory tests and radiographs because of paresthesin in bilateral lower extremities.

RESULTS

Evaluation revealed a "cyst" that was separated from the proper subarachnoid space and a disc herniation.

CONCLUSIONS

Intraspinal cyst and multilevel disc herniations could coexist in Scheuermann's disease. Both could contribute to cord compression. Drainage of the cyst, anterior decompression of the disc herniations, and interbody fusion to stabilize the diseased segments produced good results after 2 years.

Sacral insufficiency fractures. Spectrum of radiological features

Clinical and radiological features of 22 Chinese patients with sacral insufficiency fractures were reviewed. Twenty-one were postmenopausal women. Other risk factors were external pelvic radiotherapy (eight) and total hip replacement (two). Severe low back pain was the most common presenting complaint. Fractures initially were demonstrated by bone scintigraphy in 21 and computed tomography (CT) in seven patients. Concomitant parasymphyseal and pubic rami fractures were detected in 17 and 10 patients, respectively. Follow-up assessment by CT and bone scintigraphy in five patients showed various stages of fracture healing. Recognition of the radiological patterns of this entity is emphasized.

Lumbar spinal mobility after short anterior interbody fusion

STUDY DESIGN

Segmental deformations of the lumbar spine in asymptomatic volunteers measured radiologically were compared with those in patients who underwent anterior interbody fusion.

OBJECTIVE

To determine the effects of anterior lumbar interbody fusion on the juxta-fused segments.

SUMMARY OF BACKGROUND DATA

Stiffness of a spinal segment after fusion was thought to be the cause of the degeneration process at the juxta-fused segments.

METHODS

Segmental deformations of the lumbar spine, from maximum extension to maximum flexion, in 30 asymptomatic volunteers and 52 pain-free patients who had single-level L4-L5 or double-level L4-S1 fusion were measured and compared.

RESULTS

The total flexibility of the lumbar spine was decreased after a single-level fusion and further decreased after double-level fusions. The segmental deformations of the juxta-fused segments also were decreased after either a single- or double-level fusion.

CONCLUSIONS

During normal flexion and extension of the lumbar spine, the juxta-fused segments were not deformed beyond their physiological limits after fusion. Thus, accelerated degeneration observed at a juxta-fused segment is unlikely to be attributable to hypermobility.

Radiologic case. Clinics in diagnostic imaging (1). Ankylosing spondylitis with complication of pseudoarthrosis

A 41-year-old Chinese woman with quiescent ankylosing spondylitis presented with increasingly severe, recurrent back pain. The thoracolumbar junction was focally tender on palpation. Radiographs and computerised tomography demonstrated T12/L1 pseudoarthrosis. Excision of pseudoarthrosis, followed by anterior and posterior spinal fusion were performed with good results. The clinical features, pathogenesis, and management of this complication are discussed. Imaging of pseudoarthrosis in ankylosing spondylitis is emphasized.

Vertebral growth after posterior spinal fusion for idiopathic scoliosis in skeletally immature adolescents. The effect of growth on spinal deformity

We studied 29 girls and one boy with adolescent idiopathic scoliosis who were at Risser grade 0 at the time of posterior spinal fusion and were followed until maturity (mean 7.8 years). We used serial radiographs to measure the ratio of disc to vertebral height in the fused segments and to detect differential anterior spinal growth and assess its effect on scoliosis, vertebral rotation, kyphosis, and rib-vertebral-angle difference (RVAD). From one year after surgery to the latest review, the percentage anterior disc height decreased by nearly one-half and the percentage posterior disc height by nearly one-third in the fused segments (p < 0.001). There was a 4 degree increase in mean Cobb angle (p < 0.001), 11 patients (37%) having an increase of between 6 degrees and 10 degrees. There was a significant increase in mean apical rotation by 2 degrees (p = 0.003), and four patients (13%) had an increase of between 6 degrees and 16 degrees. There was little change in kyphosis. There was an increase in mean RVAD by 4 degrees (p = 0.003), seven patients (23%) showing a reduction by 1 degree to 7 degrees, and 11 (37%) increases of between 6 degrees and 16 degrees. Spinal growth occurs after posterior fusion in adolescents who are skeletally immature, as a result of continued anterior vertebral growth. There is some progression of scoliosis, vertebral rotation, and RVAD, but little change in kyphosis. The increase in deformity is not enough to warrant the use of combined anterior and posterior fusion. The findings are relevant to the management of progressive curves, the timing and extent of surgery, and the prognosis for progression of deformity in this group of patients.

Vertebral growth after posterior spinal fusion for idiopathic scoliosis in skeletally immature adolescents. The effect of growth on spinal deformity

We studied 29 girls and one boy with adolescent idiopathic scoliosis who were at Risser grade 0 at the time of posterior spinal fusion and were followed until maturity (mean 7.8 years). We used serial radiographs to measure the ratio of disc to vertebral height in the fused segments and to detect differential anterior spinal growth and assess its effect on scoliosis, vertebral rotation, kyphosis, and rib-vertebral-angle difference (RVAD). From one year after surgery to the latest review, the percentage anterior disc height decreased by nearly one-half and the percentage posterior disc height by nearly one-third in the fused segments (p < 0.001). There was a 4 degree increase in mean Cobb angle (p < 0.001), 11 patients (37%) having an increase of between 6 degrees and 10 degrees. There was a significant increase in mean apical rotation by 2 degrees (p = 0.003), and four patients (13%) had an increase of between 6 degrees and 16 degrees. There was little change in kyphosis. There was an increase in mean RVAD by 4 degrees (p = 0.003), seven patients (23%) showing a reduction by 1 degree to 7 degrees, and 11 (37%) increases of between 6 degrees and 16 degrees. Spinal growth occurs after posterior fusion in adolescents who are skeletally immature, as a result of continued anterior vertebral growth. There is some progression of scoliosis, vertebral rotation, and RVAD, but little change in kyphosis. The increase in deformity is not enough to warrant the use of combined anterior and posterior fusion. The findings are relevant to the management of progressive curves, the timing and extent of surgery, and the prognosis for progression of deformity in this group of patients.

Cancellous screw fixation for subcapital femoral neck fractures

Experience in treating 80 subcapital femoral neck fractures by AO/ASIF cancellous screws is reported. Immediate full-weight bearing was allowed routinely. The mean follow-up was 28 months. Non-union occurred in 2% and late segmental collapse in 12% of patients with undisplaced fractures. Non-union occurred in 16.7% and late segmental collapse in 30% of patients for displaced fractures. Regression of screws occurred in 30% of patients, all of which were detected within the first month after the operation. It was associated with a significantly higher risk of non-union and late segmental collapse for both undisplaced (P < 0.01) and displaced (P < 0.001) fractures.

Pseudoarthrosis in ankylosing spondylitis

Images

Nine-year mean follow-up of one-stage anteroposterior excision of hemivertebrae in the lumbosacral spine

Six patients with lumbosacral hemivertebrae were treated by one-stage anterior and posterior excision of the hemivertebrae. Long-term follow-up is reported. Overall, correction of the lumbosacral curve was 46%, including one case of pseudarthrosis and subsequent loss of correction. More importantly, truncal imbalance was restored unless other congenital thoracic anomalies were present. New methods of calculating rib cage shift on the pelvis as well as vertebral column displacement from the sagittal plane are presented.

Sequential fractures of both hips in elderly patients--a prospective study

Thirty-five patients with sequential fractures of both hips were studied prospectively. The second hip fractures occurred more commonly if the patients were institutionalized, if they suffered from concomitant neurologic diseases such as previous stroke or Parkinsonism, or if there was biochemical evidence of osteomalacia. Twelve patients sustained the contralateral hip fracture within 12 months of the first one. There was a significant correlation between biochemical evidence of osteomalacia and early occurrence of the second hip fracture. Although rehabilitation was difficult for such patients, it was possible with a longer period of intensive physiotherapy; only three patients were not able to walk upon discharge from the hospital after the second hip fracture.

Effect of treated infection on microvascular anastomosis

The effect of established infection with penicillin-resistant Staphylococcus aureus on microarterial and microvenous anastomosis was studied in a rat experimental model. The infection was treated with wound debridement and systemic antibiotics at the time of the surgical procedure. It was found that the patency rate of microarterial repairs at 10-14 days was 95.1%. Veins were less resistant to infection than arteries. Two types of vein involvement were found. These were classified according to the degree of thrombosis resulting from endophlebitis. The patency rate of anastomoses performed on the more mildly infected veins was 56.5% and that on the more severely infected veins was 0%.

A prospective study on hip fractures in patients with previous cerebrovascular accidents

Of 1430 patients with proximal femoral fractures admitted into Queen Mary Hospital, Hong Kong from 1985 to 1990, 146 patients (10.2 per cent) had a history of previous cerebrovascular accidents. The fracture was on the hemiplegic side in 82 percent of patients. Most patients were treated by operation. Intensive physiotherapy was given to these patients for an average of 6 weeks. The prefracture walking ability was regained or even improved upon discharge in 60.9 per cent of patients. After an average follow-up of 21 months, 31 per cent had satisfactory walking and active daily activities. There was significant correlation of the performance upon discharge from the hospital with the walking ability at the final follow-up.