Effect of capacitive coupled electrical stimulation on regenerate bone.

An in vivo study was carried out to determine if capacitive coupled electrical stimulation increased the rate of recovery of strength of regenerate bone produced as a result of lengthening by the Ilizarov technique. Thirty-four adult male beagles underwent a right tibial mid-diaphyseal corticotomy, followed by a 5-day delay, and then 21 days of lengthening (1 mm/day). At the start of the post-distraction period (day 27), stimulation (3-6.3 V peak to peak, 5-10 mA root-mean-square at 60 kHz) was applied for 28 days to one group. The nonstimulated group (n = 17) underwent a 28-day period with no stimulation. From each group, four tibiae were prepared for histology; both ends of the remaining bones were embedded in polymethylmethacrylate and tested in torsion (internal rotation at 4.7 degrees/sec) until failure. Statistically significant changes included a 37% lower maximum torque capacity and a 40% decrease in strain energy to failure in the stimulated group compared with the nonstimulated group. The findings are supported by measured trends to a lower modulus of rigidity (37% decrease) and a smaller percentage of active osteoid perimeter (20% decrease) for the stimulated group. The experimental data suggest that when this dose of capacitive coupled electrical stimulation is applied to the regenerating bone created during distraction osteogenesis, it delays the recovery of bone strength compared with an untreated control.

Application of thoracoscopy for diseases of the spine.

For anterior approaches to the thoracic spine, a posterolateral thoracotomy has been the standard approach. Recent expanded experience with video-assisted thoracic surgical techniques has allowed us to perform many thoracic spine procedures that previously required open approaches. These procedures include drainage of spinal abscesses, biopsy of vertebral bodies, discectomy for a herniated nucleus pulposus, and anterior releases for kyphoscoliosis. All procedures were successful, but experience is limited and follow-up still short. It is hoped that further experience will prove that this less invasive approach can be widely applied in the practice of thoracic spinal surgery.

Morphologic and histochemical characteristics of skeletal muscle after long-term intramuscular electrical stimulation.

The purpose of this investigation was to examine the morphologic and histochemical characteristics of paraspinal muscles in patients with scoliosis after long-term electrical stimulation. Thirty-six children with idiopathic scoliosis, who had been treated with implantable muscle stimulators, had paraspinal muscle biopsies at the time of implantable muscle stimulator removal. Group A patients whose curve did not progress, had 2.9 years of stimulation stopped at skeletal maturity, with a further 1.5 years of nonstimulation before implant removal and biopsy. In group B patients, who had an average of 2.3 years of stimulation, the curve progressed and stimulation was continued until fusion and biopsy. Neither group showed any increase in the frequency of pathologic changes of paraspinal muscles contrasted with values reported in the literature for scoliotic muscle. In group A patients there was an increased proportion of type 1 fibers on the convex side of the curve compared to the concavity. Despite this finding the curves did not require fusion, suggesting that the increased percentage of type 1 fibers was not the cause of the scoliosis. In group B patients there was an even higher type 1 concentration on the convex side contrasted to the convex side of group A patients.

Scoliosis treatment in children using a programmable, totally implantable muscle stimulator (ESI).

More than ten years ago, we began the night time treatment of early scoliosis in growing children with implanted muscle stimulators [1], [2]. The early devices were radio-frequency (RF) coupled units with an implanted receiver and external transmitter-antenna which the patient used at night to power and activate the implant. Compliance with this treatment was 95 percent. Recent developments have led to the use of a new, totally implantable stimulator for the treatment of single scoliotic curves. The unit has no external components, is programmed and interrogated by telemetry, and is externally switched by the patient using a magnet. Compliance with it continues at a high level, product reliability to date has been perfect, and the clinical results continue good.

Paraspinal muscle stimulation for the treatment of idiopathic scoliosis in children.

More than 12 years ago, we began to investigate the potential use of electrical stimulation of the paraspinal muscles to control scoliosis in children. Animal experimentation showed that unilateral stimulation of these muscles will cause the spine to grow toward the stimulated side. It was also shown that the stimulation need only be carried on for part of the day. We have developed a treatment for scoliosis based on night-time use of stimulation either with an implantable or surface system. Both single and dual channel systems are available for the treatment of single or double scoliotic curves. Treatment is carried on at night while the child is asleep, and there are no exercises or brace programs associated with it. Approximately 75% of the curves are either improved significantly, or maintained at their starting value. Only about 15% of the curves fail to respond and require a spinal fusion to stabilize them. Patient acceptance and compliance has been excellent.

Spine deformity in familial dysautonomia (Riley-Day syndrome).

Familial dysautonomia spanning a 30-year period reviewed retrospectively. The 16 patients identified included nine with spine deformities. Serious general medical problems were common. Spine deformities included kyphosis, scoliosis, or a combination of both. Brace treatment was attempted and was unsuccessful in three patients. Seven underwent surgical stabilization. Although all seven patients tolerated the surgical procedures, at least one postoperative complication was noted in each case. Follow-up ranged from 1 1/2 to 16 1/2 years. We recommend close observation of the deformities, early stabilization when disorders are progressive, and a high level of awareness of potential complications.

Butler arthroplasty for correction of the adducted fifth toe: a retrospective study of 36 operations between 1968 and 1982.

This is a retrospective study of 30 children and adolescents who have undergone Butler arthroplasty for correction of an overriding fifth toe. Bilateral operations were performed on six patients, giving a total of 36 operations. Good to excellent results were obtained in 34 of the 36 operations. With attention to detail, this is a simple and safe operation. Full correction is obtainable without postoperative splintage or cast immobilization. This study represents the only reported experience in North America of this little-known procedure.

Limp affecting the hip and knee in children.

Limp and pain are common findings about the hip and knee in growing children. Epiphyseal growth peculiarities in children account for many of the specific disease entities. Simple but specific physical examination and mandatory simple X-rays will virtually always give or exclude a diagnosis. problems about the hip are usually serious, for example Legg-Perthes, slipped epiphysis and septic arthritis. Most childhood knee problems are annoying but not serious. Chondromalacia patellae and Osgood-Schlatter's disease seldom require treatment-but the knee is the most common site for osteogenic sarcoma.

Incidence, natural history, and treatment of scoliosis in Friedreich's ataxia.

We carried out a retrospective study of 42 patients with documented Friedreich's ataxia to answer four questions: what is the incidence and natural history of scoliosis in Friedreich's ataxia, and what are the results of operative and nonoperative treatment? We concluded that the incidence of scoliosis in true Friedreich's ataxia is extremely high. The curves tend to progress with the severity of the disease and often tend to progress after skeletal maturity. Bracing and electrospinal instrumentation have no role in treatment. Patients with progressive curves should have early surgical stabilization.

The congenital undescended scapula. Surgical correction by the woodward procedure.

At The Hospital for Sick Children in Toronto, 21 undescended scapulae were corrected by the Woodward procedure in 20 patients over the past 18 years. The average age at operation was six years six months. The average follow-up period after operation was 8 years 9 months. Fifteen patients were girls and five were boys. All the patients had other associated abnormalities. Only one patient had a concomitant clavicular osteotomy. The average increase in glenohumeral abduction was 37 degrees. The average scapular lowering was two centimetres. Excellent or good cosmetic results were obtained in 80 per cent of patients. Ninety-three per cent of patients expressed satisfaction with the operative results. Complications were few. The Woodward procedure is a safe and relatively straightforward surgical means to effect a good cosmetic and functional improvement in a patient with a congenital undescended scapula. We do not recommend clavicular osteotomy as a routine, but it may be added to gain more correction with less risk of neurovascular compression.

The response of articular cartilage to the in vivo replacement of synovial fluid with saline.

Experiments on rabbits were performed to determine whether continuous irrigation of a synovial joint produced irreversible degenerative changes in the articular cartilage. Continuous irrigation of a synovial joint permits observations of the effect on articular cartilage of altering the intra-articular environment. The right knee joints were irrigated with normal saline for varying periods, up to 14 days, and the left knees served as nonirrigated controls. One group of animals (short-term) was killed immediately following irrigation, while another group (long-term) was assessed after six months of cage activity following the irrigation period. Within each group, half were skeletally immature and half were mature. No differences in cell density, nuclei-to-lacunae ratio, or the ratio of calcified layer to total cartilage thickness were found in any group. Irrigation did produce a significant reduction in matrix staining with safranin-O. This was first detectable following three days of irrigation and was severe by seven to 14 days. Staining properties returned to normal after six months of cage activity. No obvious difference was found between immature and mature animals.

Electrical stimulation for scoliosis.

Scoliosis is detectable in 6 to 14 percent of school-age children. An estimated 0.1 percent of the curvatures are progressive and require treatment. The usual method of treatment consists of a restrictive brace worn most of the time. A successful and nonrestrictive technique utilizing electrical stimulation of the deep paraspinal muscles has been developed. Therapy involves night-time use of an implanted stimulator system. It places no restrictions on the child's activities, while producing results that are superior to bracing.

Aeromedical transport: its hidden problems.

Air transport can move patients safely and rapidly over long distances. However, changes in altitude can have disastrous effects because diminished ambient air pressure may allow gases in closed spaces and tissues to expand rapidly. Even pressurized commercial aircraft do not maintain sea-level pressure: cabin pressures equal to those at yp to 8000 ft may be experienced, diminishing oxygen tension in proportion. Air transport is absolutely contraindicated for patients with untreated pneumothorax, gas gangrene, or air trapped in the cranium and those who have recently undergone abdominal surgery. Special considerations including a planned low-altitude flight are warrented for patients who are anemic, in respiratory or cardiac distress, or immobilized in casts, or who have been engaged in underwater diving immediately before the flight.

Computerized axial tomography to demonstrate occult fractures of the acetabulum in children.

Following hip trauma in children an intra-articular osteocartilaginous fragment may be retained within the hip joint. This fragment may not be visualized by plain films or arthrography. However, computerized tomography clearly demonstrated such fragments in the two children with post-traumatic painful hips reported in this paper.

Surgical management of thoracic kyphosis in adolescents.

Twenty-seven patients of a group of twenty-nine who underwent posterior spine fusion using Harrington compression instrumentation for Scheuermann's disease or postural roundback deformity were reviewed with a mean follow-up of 27.6 months. The mean curve before operation was 72 degrees and at review, 46.1 degrees. The mean loss of correction in the fusion from initial examination to final follow-up was 5.7 degrees. This procedure can achieve satisfactory correction of deformity as well as pain relief. We think that Harrington compression instrumentation and spine fusion is indicated in selected cases of roundback deformity.