Metabolic effects of sleep disruption, links to obesity and diabetes.

PURPOSE OF REVIEW: To highlight the adverse metabolic effects of sleep disruption and to open ground for research aimed at preventive measures. This area of research is especially relevant given the increasing prevalence of voluntary sleep curtailment, sleep disorders, diabetes, and obesity. RECENT FINDINGS: Epidemiological studies have established an association between decreased self-reported sleep duration and an increased incidence of type 2 diabetes (T2D), obesity, and cardiovascular disease. Experimental laboratory studies have demonstrated that decreasing either the amount or quality of sleep decreases insulin sensitivity and decreases glucose tolerance. Experimental sleep restriction also causes physiological and behavioral changes that promote a positive energy balance. Although sleep restriction increases energy expenditure because of increased wakefulness, it can lead to a disproportionate increase in food intake, decrease in physical activity, and weight gain. SUMMARY: Sleep disruption has detrimental effects on metabolic health. These insights may help in the development of new preventive and therapeutic approaches against obesity and T2D based on increasing the quality and/or quantity of sleep.

Junctional spinal disorders in operated adult spinal deformities: present understanding and future perspectives.

INTRODUCTION: Junctional spinal disorders have become one of the greatest challenges in spinal deformity surgery. They can occur at any age but are mostly seen in adult deformity surgery and are most often observed as the patient gets older. DEFINITIONS: Different forms can be individualized according to their types and location: one can observe simple segmental degeneration above or below instrumentation with or without spinal stenosis. Or the situation may be more complex with proximal junctional kyphosis, distal junctional kyphosis and intercalary junctional kyphosis where the junctional kyphosis occurs between two instrumented segments of the spine. Junctional scoliosis may also be observed as a new curve that did not exist after the index surgery. PATHOPHYSIOLOGY: Many different factors have been described being associated or the cause of junctional problems: old age, increased BMI, osteoporosis, etc. The role of pre-existing and postoperative sagittal imbalance plays a definitive role in their pathogenesis. As well the weakened posterior elements and or fatty degeneration of the posterior muscles are key factors in the occurrence of these problems. Multiple different radiologic parameters to describe and achieve perfect sagittal balance have been described knowing that the pelvic incidence of the patients is the key element that governs lumbar lordosis of the patient and hence the sagittal balance. Away from the spine one has to integrate the issues of the knees and the hips in the presentation of these junctional problems whether they are the cause or one of the consequences of the sagittal malalignment. Likewise the non-instrumented part of the spine (thoracic and or cervical spine) will also play a role in the pathogenesis or prevention of these junctional problems if they are stiff and or autofused along with their respective deformity. TREATMENT: To prevent the occurrence of such junctional problems some basic surgical rules must be observed, but still lots remain unknown such as how much restoration of lordosis is really necessary, how to create a smoother transition between the instrumented and non-instrumented spine, which metal and where to use it, which implants to use as our widely used pedicle screw system may be one of the causes of these problems. Clinically these junctional problems can be asymptomatic and require only observation, or require revision surgery. Revision will require in most cases decompression of the neural elements, extension of the instrumentation and spinal osteotomies. CONCLUSION: Definitively the issue of junctional spinal disorder after deformity surgery will require further extensive research to minimize this problem especially in our aging population.

Effects of sleep restriction on glucose control and insulin secretion during diet-induced weight loss.

Insufficient sleep is associated with changes in glucose tolerance, insulin secretion, and insulin action. Despite widespread use of weight-loss diets for metabolic risk reduction, the effects of insufficient sleep on glucose regulation in overweight dieters are not known. To examine the consequences of recurrent sleep restriction on 24-h blood glucose control during diet-induced weight loss, 10 overweight and obese adults (3F/7M; mean (s.d.) age 41 (5) years; BMI 27.4 (2.0) kg/m(2)) completed two 14-day treatments with hypocaloric diet and 8.5- or 5.5-h nighttime sleep opportunity in random order 7 (3) months apart. Oral and intravenous glucose tolerance test (IVGTT) data, fasting lipids and free fatty acids (FFA), 24-h blood glucose, insulin, C-peptide, and counter-regulatory hormone measurements were collected after each treatment. Participants had comparable weight loss (1.0 (0.3) BMI units) during each treatment. Bedtime restriction reduced sleep by 131 (30) min/day. Recurrent sleep curtailment decreased 24-h serum insulin concentrations (i.e., enhanced 24-h insulin economy) without changes in oral glucose tolerance and 24-h glucose control. This was accompanied by a decline in fasting blood glucose, increased fasting FFA, which suppressed normally following glucose ingestion, and lower total and low-density lipoprotein cholesterol concentrations. Sleep-loss-related changes in counter-regulatory hormone secretion during the IVGTT limited the utility of the test in this study. In conclusion, sleep restriction enhanced 24-h insulin economy without compromising glucose homeostasis in overweight individuals placed on a balanced hypocaloric diet. The changes in fasting blood glucose, insulin, lipid and FFA concentrations in sleep-restricted dieters resembled the pattern of human metabolic adaptation to reduced carbohydrate availability.

Insufficient sleep undermines dietary efforts to reduce adiposity.

BACKGROUND: Sleep loss can modify energy intake and expenditure. OBJECTIVE: To determine whether sleep restriction attenuates the effect of a reduced-calorie diet on excess adiposity. DESIGN: Randomized, 2-period, 2-condition crossover study. SETTING: University clinical research center and sleep laboratory. PATIENTS: 10 overweight nonsmoking adults (3 women and 7 men) with a mean age of 41 years (SD, 5) and a mean body mass index of 27.4 kg/m² (SD, 2.0). INTERVENTION: 14 days of moderate caloric restriction with 8.5 or 5.5 hours of nighttime sleep opportunity. MEASUREMENTS: The primary measure was loss of fat and fat-free body mass. Secondary measures were changes in substrate utilization, energy expenditure, hunger, and 24-hour metabolic hormone concentrations. RESULTS: Sleep curtailment decreased the proportion of weight lost as fat by 55% (1.4 vs. 0.6 kg with 8.5 vs. 5.5 hours of sleep opportunity, respectively; P = 0.043) and increased the loss of fat-free body mass by 60% (1.5 vs. 2.4 kg; P = 0.002). This was accompanied by markers of enhanced neuroendocrine adaptation to caloric restriction, increased hunger, and a shift in relative substrate utilization toward oxidation of less fat. LIMITATION: The nature of the study limited its duration and sample size. CONCLUSION: The amount of human sleep contributes to the maintenance of fat-free body mass at times of decreased energy intake. Lack of sufficient sleep may compromise the efficacy of typical dietary interventions for weight loss and related metabolic risk reduction. PRIMARY FUNDING SOURCE: National Institutes of Health.

Exposure to recurrent sleep restriction in the setting of high caloric intake and physical inactivity results in increased insulin resistance and reduced glucose tolerance.

CONTEXT: Epidemiological data indicate that reduced sleep duration is associated with increased incidence of type-2 diabetes. OBJECTIVE: The aim of the study was to test the hypothesis that, when part of a Western-like lifestyle, recurrent bedtime restriction may result in decreased glucose tolerance and reduced insulin secretion and action. DESIGN AND SETTING: We conducted a randomized crossover study at a university clinical research center and sleep research laboratory. PARTICIPANTS: Eleven healthy volunteers (five females and six males) with a mean (+/-sd) age of 39 +/- 5 yr and body mass index of 26.5 +/- 1.5 kg/m(2) participated in the study. INTERVENTION: The study included two 14-d periods of controlled exposure to sedentary living with ad libitum food intake and 5.5- or 8.5-h bedtimes. MAIN OUTCOME MEASURES: Oral and iv glucose challenges were used to obtain measures of glucose tolerance, glucose effectiveness, insulin secretion, and insulin sensitivity at the end of each intervention. Secondary measures included circulating concentrations of the glucose counter-regulatory hormones, cortisol, GH, epinephrine, and norepinephrine. RESULTS: Bedtime restriction reduced daily sleep by 122 +/- 25 min. Both study periods were associated with comparable weight gain; however, recurrent sleep restriction resulted in reduced oral glucose tolerance (2-h glucose value, 144 +/- 25 vs. 132 +/- 36 mg/dl; P < 0.01) and insulin sensitivity [3.3 +/- 1.1 vs. 4.0 +/- 1.6 (mU/liter)(-1) x min(-1); P < 0.03], and increased glucose effectiveness (0.023 +/- 0.005 vs. 0.020 +/- 0.005 min(-1); P < 0.04). Although 24-h cortisol and GH concentrations did not change, there was a modest increase in 24-h epinephrine and nighttime norepinephrine levels during the 5.5-h bedtime condition. CONCLUSIONS: Experimental bedtime restriction, designed to approximate the short sleep times experienced by many individuals in Westernized societies, may facilitate the development of insulin resistance and reduced glucose tolerance.

Sleep curtailment is accompanied by increased intake of calories from snacks.

BACKGROUND: Short sleep is associated with obesity and may alter the endocrine regulation of hunger and appetite. OBJECTIVE: We tested the hypothesis that the curtailment of human sleep could promote excessive energy intake. DESIGN: Eleven healthy volunteers [5 women, 6 men; mean +/- SD age: 39 +/- 5 y; mean +/- SD body mass index (in kg/m(2)): 26.5 +/- 1.5] completed in random order two 14-d stays in a sleep laboratory with ad libitum access to palatable food and 5.5-h or 8.5-h bedtimes. The primary endpoints were calories from meals and snacks consumed during each bedtime condition. Additional measures included total energy expenditure and 24-h profiles of serum leptin and ghrelin. RESULTS: Sleep was reduced by 122 +/- 25 min per night during the 5.5-h bedtime condition. Although meal intake remained similar (P = 0.51), sleep restriction was accompanied by increased consumption of calories from snacks (1087 +/- 541 compared with 866 +/- 365 kcal/d; P = 0.026), with higher carbohydrate content (65% compared with 61%; P = 0.04), particularly during the period from 1900 to 0700. These changes were not associated with a significant increase in energy expenditure (2526 +/- 537 and 2390 +/- 369 kcal/d during the 5.5-h and 8.5-h bedtime periods, respectively; P = 0.58), and we found no significant differences in serum leptin and ghrelin between the 2 sleep conditions. CONCLUSIONS: Recurrent bedtime restriction can modify the amount, composition, and distribution of human food intake, and sleeping short hours in an obesity-promoting environment may facilitate the excessive consumption of energy from snacks but not meals.

Congenital scoliosis.

Congenital scoliosis is the most frequent congenital deformity of the spine. Congenital curvatures are due to anomalous development of the vertebrae (failure of formation and/or segmentation). Congenital scoliosis is believed to be related to an insult to the fetus during spine embryological development, and associated malformations (heart, spinal cord, kidney.) are frequently observed. A perfect understanding of the natural history of the deformity and the treatment principles will allow best management of these complex spine deformities. New imaging techniques like three-dimensional computed tomography (CT) and magnetic resonance imaging (MRI) are important tools for analyzing the underlying deformity and understanding the evolution of the complex deformities. The mainstay of treatment is either observation or, in case of curve progression (>10 degrees /year), surgery. Different surgeries are described with two main principles: (1) prophylactic surgeries like hemiepiphysiodesis or in situ fusions that will prevent worsening or allow progressive correction over time, and (2) corrective surgeries, with spinal fusion with or without spinal resection. Exceptional procedures (e.g. spinal column resection or halo distraction) can be attempted in cases of very severe deformity. Congenital curves must be carefully observed to choose the least invasive procedure at the right time and to minimize spinal cord risks.

Elevated synthetic activity in the convex side of scoliotic intervertebral discs and endplates compared with normal tissues.

STUDY DESIGN: We measured concentrations of specific molecules reflecting matrix synthesis and degradation in normal and scoliotic intervertebral discs and endplates. OBJECTIVES: The aim of this work was to quantitate markers of matrix turnover in normal versus adolescent idiopathic scoliotic intervertebral discs and cartilaginous endplates. SUMMARY OF BACKGROUND DATA: Changes in the intervertebral disc and endplate composition have been implicated as possible etiologic factors in the pathogenesis of adolescent idiopathic scoliosis. To better understand this process, it is important to compare the turnover of matrix components in scoliotic and normal intervertebral disc and endplate tissues. This comparison may help to improve our understanding of the role that disc and endplate tissues may play in the induction and/or progression of idiopathic scoliosis. METHODS: Fifteen scoliotic and 17 normal intervertebral discs and endplates were analyzed for their water, collagen, proteoglycan, and protein content. In addition, newly synthesized aggrecan and collagen Types I and II were measured. Percent total denatured collagen was also determined. RESULTS: The total collagen content was significantly lower in the scoliotic anulus and endplate regions, whereas glycosaminoglycan (GAG) content was significantly lower in the scoliotic endplates and nucleus regions. Conversely, total protein content was significantly higher in scoliotic endplates and elevated in scoliotic nucleus regions. Water content was significantly lower in the scoliotic anulus and endplate regions. When comparing the concave and convex regions of scoliotic endplates, there was no significant difference in concentration of any matrix component. The major difference in the synthetic marker levels relates to the synthesis of Type II collagen, which was higher in the nucleus, anulus, and endplate regions of scoliotic discs than in the corresponding regions of normal tissues. By contrast, the percent total denatured collagen was significantly elevated in the nucleus of normal tissues compared with the scoliotic ones. CONCLUSIONS: The higher collagen Type II synthetic levels and increased total protein content with no matrix turnover suggest that scoliotic changes are due to an altered and ineffective synthetic response to a pathologic mechanical environment.

Decompensation following scoliosis surgery: treatment by decreasing the correction of the main thoracic curve or "letting the spine go".

Coronal decompensation following correction of adolescent idiopathic scoliosis (AIS) has been reported to be due to the Cotrel-Dubousset rod derotation maneuver, or to a hypercorrection of the main thoracic curve. The treatment of such decompensation consists classically in observation, bracing, or extension of the instrumentation in the lumbar spine for a King 2 curve, or in the upper thoracic spine for a King 5 curve. As the postoperative decompensation is related to a hypercorrection of the main thoracic curve (relative to the compensatory curve), we hypothesized that if we were to "let the spine go" to some of its initial deformity, the balance of the patient would be improved. The purpose of the study was therefore to report on two cases where a postoperative imbalance following scoliosis surgery was successfully treated by decreasing the correction of the main thoracic curve. Two patients with AIS were found to have significant imbalance after scoliosis surgery. Both patients had been treated for a right thoracic curve (82 degrees and 85 degrees respectively) with an anterior release and posterior instrumentation. The revision surgery consisted for both patients in removing all the hooks between the end vertebrae of the main thoracic curve. This was done before the 3rd postoperative month for both patients. After revision surgery, the balance of both patients improved dramatically within a few weeks. The shoulders became almost level, and the trunk shift improved concomitantly. The Cobb angle increased by 8 degrees and 10 degrees, and the apical vertebra shifted to the right by 15 and 10 mm for the respective patients. These results were stable at 1-year follow-up. In the event of a persisting imbalance, we recommend, in selected cases, letting the spine go by removing all the implants located between the end vertebrae of the main thoracic curve. This adjustment or fine-tuning of the instrumentation should be done before the fusion takes place, and is best achieved with an instrumentation in which the hooks can be easily removed from the rod.

Transient exotropia after posterior spinal fusion in a child: a new case.

Ocular complications after spinal surgery are rare, although ischemic optic neuropathy, occipital lobe infarcts, and central retinal vein thrombosis have been reported. Our purpose is to report a case of an acute, comitant, postoperative exotropia that rapidly and spontaneously resolved. This case is particularly interesting in that it may indirectly shed some light on mechanisms of vergence control.

Anterior thoracoscopic spine release in deformity surgery: a meta-analysis and review.

Videoassisted thoracoscopic surgery (VATS) allows the surgeon to perform an anterior thoracoscopic spine release for spinal deformities. It is an alternative to open thoracotomy. Several years after its introduction the present author gives an update on the indications, surgical techniques, results, and complications of this new technology. A meta-analysis of previously published papers is organized in tables in an attempt to answer all the questions and controversies that this technique has aroused. A series of ten selected articles were available for review, comprising a total of 151 procedures. No study had any long-term follow-up. Most series were pediatric and involved a variety of etiologies (mostly neuromuscular, adolescent idiopathic scoliosis, and Scheuermann's kyphosis). The surgical technique was for most authors a convex side approach in the lateral decubitus through four or more ports in the anterior or midaxillary line. Single lung ventilation was used in most cases. Posterior surgery was carried out the same day in most cases. The total number of discs excised varied between 4 and 7, but the quality of disc excision was rarely reported. Most authors carried out a spine fusion at the time of the disc release. The total VATS procedure lasted between 2 h 30 min and 4 h, depending on the series and the surgeon's previous experience. In most series curves were in the range of 55 degrees-80 degrees, with an average of 65 . The percentage of Cobb angle correction was 55%-63% after VATS and posterior spine fusion. For kyphotic deformities only one series had significant numbers to allow conclusions to be drawn. The mean preoperative Cobb angle was 78 degrees and postoperatively the kyphosis was corrected to 44 degrees. Length of hospital stay was quite similar in most series and was around 9 days. The cost of the VATS procedure was studied in one series and was found to be 28% more expensive than thoracotomy. The total complications reported were 18%; most were pulmonary complications with prolonged ventilatory support in patients with neuromuscular pathologies. The VATS procedure has been used with success in most series for pediatric curves (average Cobb angle of 65 degrees or kyphosis of 75 degrees). No report of the surgical outcome (balance, rate of fusion, rib hump correction, cosmetic correction, pain, and patient satisfaction) was available for any series. Further prospective study including these parameters will be required to determine the real benefit of such procedures to the patient, bearing in mind that the correction of spinal deformities is the result of the surgeon's experience, skill, and the available technology.

Adolescent idiopathic thoracic scoliosis: apical correction with specialized pedicle hooks.

Forty-one patients with thoracic adolescent idiopathic scoliosis (AIS) treated with only a posterior spine fusion using specialized pedicle hooks (SPH) (hooks augmented with 3.2-mm screws) at the apex of the curve were reviewed in order to assess the effectiveness of this correction method. Inclusion in the study group required a minimum of 2 years' follow-up and the same strategy of correction where the apical vertebrae (3 or 4 vertebrae on the concave side) were instrumented with SPH. The mean preoperative Cobb angle was corrected from 55 degrees (42 degrees -80 degrees) to 18 degrees (67%) postoperatively and to 23 degrees (58%) at the last follow-up (28-50 months) for a flexibility index of 46%. Apical vertebral translation was corrected to 70% at the last follow-up. Thoracic kyphosis remained unchanged, from 23 degrees to 26 degrees, and the lumbar lordosis went from -53 degrees to -59 degrees. The lumbar curve was corrected from 38 degrees to 18 degrees. Coronal balance improved from 10 to 1 mm; shoulder balance was improved from 15 to 5 mm. The rib hump was improved from an average of 30 mm preoperatively to 15 mm postoperatively, but only to 25 mm at the last follow-up (17% of correction). One case of a spastic bladder was observed postoperatively, which resolved completely after 8 months. Three patients had to have their instrumentation removed because of pain. There was no complication related to the use of the SPH. The authors conclude that apical correction with SPH allows effective scoliosis correction without spinal distraction and does not require supra- or infralaminar hook in the spinal canal.

Halo femoral traction and sliding rods in the treatment of a neurologically compromised congenital scoliosis: technique.

In severe congenital scoliosis, traction (whether with a halo or instrumental) is known to expose patients to neurologic complications. However, patients with restrictive lung disease may benefit from halo traction during the course of the surgical treatment. The goal of treatment of such deformities is, therefore, twofold: improvement of the respiratory function and avoidance of any neurologic complications. We report our technique to treat a 17-year-old girl with a multi-operated congenital scoliosis of 145 degrees and cor pulmonale. Pre-operative halo gravity traction improved her vital capacity from 560 c.c. to 700 c.c., but led to mild neurologic symptoms (clonus in the legs). To avoid further neurologic compromise, her first surgery consisted of posterior osteotomies and the implantation of two sliding rods connected to loose dominoes without any attempt at correction. Correction was then achieved over a 3-week period with a halofemoral traction. This allowed the two rods to slide while the neurologic status of the patient was monitored. Her definitive surgery consisted of locking the dominoes and the application of a contralateral rod. Satisfactory outcome was achieved for both correction of the deformity (without neurologic sequels) and improvement of her pulmonary function (1200 c.c. at 2 years). This technique using sliding rods in combination with halofemoral traction can be useful in high-risk, very severe congenital scoliosis.

The 'MW' sacropelvic construct: an enhanced fixation of the lumbosacral junction in neuromuscular pelvic obliquity.

Fixation to the lumbosacral spine to correct pelvic obliquity in neuromuscular scoliosis has always remained a surgical challenge. The strongest fixation of the lumbosacral junction has been achieved with either a Galveston technique with rods or screws or with iliosacral screws. We have devised a new fixation system, in which iliosacral screws are combined with iliac screws. This is made possible by using the AO Universal Spine System with side opening hooks above and below the iliosacral screws and iliac screws below it. The whole sacropelvis is thus encompassed by a maximum width (MW) fixation, which gives an 'M' appearance on the pelvic radiographs and a 'W' appearance in the axial plane. We report on our surgical technique and the early results where such a technique was used. We feel that this new means of fixation (by combining the strongest fixation systems) is extremely solid and should be included in the wide armamentarium of sacropelvic fixation.

Unusual presentation of spinal cord compression related to misplaced pedicle screws in thoracic scoliosis.

Utilization of thoracic pedicle screws is controversial, especially in the treatment of scoliosis. We present a case of a 15-year-old girl seen 6 months after her initial surgery for scoliosis done elsewhere. She complained of persistent epigastric pain, tremor of the right foot at rest, and abnormal feelings in her legs. Clinical examination revealed mild weakness in the right lower extremity, a loss of thermoalgic discrimination, and a forward imbalance. A CT scan revealed at T8 and T10 that the right pedicle screws were misplaced by 4 mm in the spinal canal. At the time of the revision surgery the somatosensory evoked potentials (SSEP) returned to normal after screw removal. The clinical symptoms resolved 1 month after the revision. The authors conclude that after pedicle instrumentation at the thoracic level a spinal cord compression should be looked for in case of subtle neurologic findings such as persistent abdominal pain, mild lower extremity weakness, tremor at rest, thermoalgic discrimination loss, or unexplained imbalance.

Correction of adolescent idiopathic thoracic scoliosis with a new type of offset apical instrumentation: preliminary results.

Twenty patients were operated on with the same method using the AO Universal Spine System. The entire apex of the curvature was instrumented on the concave side with a newly designed pedicle hook augmented by 3.2-mm endplate screw. An offset configuration of apical and end vertebrae implants was done to maximize translation. The concave rod was derotated to 120 degrees without any distraction. The convex side was instrumented in the usual fashion. Prospective analysis showed a mean Cobb angle correction of 63% for a mean preoperative angle of 54 degrees. The apical vertebral translation was corrected to 72%. There was no major complication at the last follow-up (18-30 months). This technique compares favorably with the ones using CD principles, but needs no distraction and no instrumentation in the canal (supra or infralaminar hook).

[Treatment of scoliosis in the adolescent by anterior release and vertebral arthrodesis under thoracoscopy. Preliminary results]. / Traitement de la scoliose de l'adolescent par libération antérieure et arthrodèse vertébrale sous thoracoscopie. Résultats préliminaires.

PURPOSE OF THIS STUDY: The purpose was to evaluate short term results of thoracoscopic anterior release and fusion in adolescent scoliosis. MATERIAL AND METHODS: An independent observer reviewed retrospectively hospital files and X-rays of 8 consecutive patients. The average follow-up was 14 months. The mean age at the time of surgery was 12 years old, all patients were skeletally immature. The surgical technique consisted in a thoracoscopic release and fusion of the discs space followed in the same time by a posterior instrumentation and fusion. Six cases were done in the prone position, two in the lateral decubitus. RESULTS: The release could be done in 7 cases. In one case a severe bronchospasm prevented from doing discectomy. Four levels in average could be released and fused. The thoracoscopic time was 240 mn in average and the total surgical time 430 mn. The bleeding of the thoracoscopic procedure was minimal (less than 200 cc) in all but one case (2000 cc). The duration of the chest tube was 4.4 days. At last follow up the cosmetic advantage was obvious. The angular correction of the Cobb angle was 63 per cent (similar to our isolated posterior instrumentation). The radiologic aspect of the anterior fusion seemed to be less satisfactory than the ones of classic thoracotomies (although we did not observe any non union). DISCUSSION: Our experience and these results moderate the initial enthusiasm of these new techniques reported in literature. Our current indications are therefore patients at risk of crankshaft, and complementary anterior fusion of dysplasic spines. As to the major curves we still recommend the anterior release through a formal thoracotomy which allows a more complete disc excision on more levels and a more abundant graft, with a shorter surgical time, with an associated morbidity which does not seem superior.

King syndrome: further clinical variability and review of the literature.

The King syndrome is characterized by a Noonan-like phenotype, the presence of a nonspecific myopathy and a predisposition to malignant hyperthermia. In some families, mild physical manifestations of the phenotype and/or elevated serum creatine phosphokinase (CPK) in relatives suggest the presence of an autosomal dominant myopathy with variable expressivity. We summarize the cases of 14 previously reported patients and describe a new patient, a 7-year-old girl, with the King syndrome and the unique findings of diaphragmatic eventration, tethered spinal cord, and severe paucity of type 2 skeletal muscle fibers. It has been proposed that the King syndrome represents a common phenotype that may result from several different slowly progressive congenital myopathies. This hypothesis, and the phenotypic overlap between the King and Noonan syndromes are discussed in light of the findings in this new patient.

SRS travelling fellowship.

A 3-week tour of the Far East was coordinated by Dr. Ronald DeWald, senior travelling fellow appointed by the Scoliosis Research Society. Three junior fellows appointed by the Education Committee of the Scoliosis Research Society accompanied him. The purpose of this fellowship was to develop a comaraderie and exchange ideas, thoughts, and experiences in the field of spinal deformity.

Modification of the original Luque technique in the treatment of Duchenne's neuromuscular scoliosis.

Luque segmental instrumentation with Galveston technique for pelvic fixation is generally used in the correction of Duchenne's neuromuscular spinal deformities with pelvic obliquity. Particularly difficult is the control of the lumbopelvic junction. Instrumentation failures and only mediocre correction of pelvic obliquity are reported. To obtain better sacropelvic anchorage and to improve pelvic correction, this technique was modified with the introduction of sacral screws in each S-1 pedicle and a device for transverse traction between the caudal right-angle bends of the L-rods. From 1988 and 1993, 25 consecutive patients (mean age, 14 years) were operated on using this technique. Before surgery, mean spinal deformity measured 68 degrees (range, 46-90 degrees), and pelvic obliquity, 21 degrees (range, 7-45 degrees). At the last examination (mean follow-up, 36 months), mean spinal curvature was 18 degrees (range, 3-37 degrees), and pelvic obliquity was always <15 degrees (range, 0-15 degrees) with mean correction of 75%. No instrumentation failure or loss of correction >3 degrees could be observed in the entire series. In every patient, a good sitting balance could be restored after surgery.