The modified Schollner costoplasty.

The modified Schollner costoplasty is a cosmetic procedure for the correction of rib prominence deformity in scoliosis. We present the results of the procedure in 21 patients who had previously undergone spinal fusion for scoliosis. We found the procedure to be well tolerated without major complications. Objective cosmetic improvement was achieved in all but one case. All but one patient considered the procedure to have been of cosmetic benefit.

The relationship between periosteal division and compression or distraction of the growth plate. An experimental study in the rabbit.

We subjected the proximal tibial growth plates of six-week-old rabbits to either compression or distraction of 1 kg on both legs. On one side the proximal tibial periosteum was divided circumferentially and stripped for 1 cm. After six weeks, growth was measured at both proximal and distal growth plates. Compression inhibited total tibial growth and distraction enhanced it. The compressed growth plate grew less and the distracted growth plate grew more, but there was a reciprocal change at the other end of the bone. Periosteal division enhanced growth at the adjacent growth plate but inhibited it distally; the effect of distraction was enhanced and that of compression reduced. We found reciprocal growth rates at the proximal and distal growth plates. Relatively small amounts of compression or distraction did affect total bone growth. Periosteal division appeared to induce overgrowth at least partly by a mechanical effect; it may be useful as an adjunct to other methods of leg lengthening, though not to epiphyseolysis.

Thoracic spine translocation without cord injury.

We report three cases of thoracic spine translocation without neurological deficit. In each case bilateral pedicular fractures, demonstrated by computed tomography, produced 'floating arches' which account for the sparing of the cord. If computed tomography demonstrates adequate canal dimensions, these patients may be treated conservatively, but the treatment of choice at specialist spinal centres is operative stabilisation.

The biomechanical effectiveness of the Boston brace in the management of adolescent idiopathic scoliosis.

The present study assesses the biomechanical effectiveness of the Boston brace on a group of 14 patients with adolescent scoliosis. Interface pressure measurements were performed at the appropriate compression pads within the brace when it was first applied and on two further sessions within the 6-month period of brace treatment. A corresponding series of Cobb angle measurements also were performed. Mean values of total force exerted through the brace of 58 +/- 18 N were associated with an initial curve correction of 37 +/- 21%. This mean force level was maintained throughout the study, although the mean curve correction at 6 months had reduced to 15 +/- 14%. In addition to biomechanical parameters, factors relating to the nature of the individual curve were important in determining the overall effectiveness of the Boston brace system.

Surface stereophotogrammetry of thoracic kyphosis.

The thoracic kyphosis angles of 16 normal individuals, 10 patients with Scheuermann's disease and 11 with adolescent idiopathic scoliosis were measured both radiographically and from Integrated Shape Imaging System (ISIS) scans obtained by surface stereophotogrammetry. There was a high correlation between the two measures. The method of kyphosis measurement from ISIS scans was then used for 30 patients with adolescent idiopathic scoliosis who underwent corrective surgery. A significant reduction in thoracic kyphosis was observed postoperatively. In another group of 28 patients managed conservatively by bracing, some hypokyphosis developed after treatment. However, we found no association between hypokyphosis and curve progression.

Back shape in brace treatment of idiopathic scoliosis.

This preliminary study has shown that bracing may improve the cosmetic appearance of a scoliotic back although the underlying curve remains unchanged. Thirty-two patients treated with the Boston brace for adolescent idiopathic scoliosis were assessed both roentgenographically and by integrated shape imaging system scanning before and after treatment. The mean follow-up time was 16 months. Surface shape improved in 41% of the patients, whereas roentgenographic improvement occurred in only 9%. Roentgenographic measurements should, therefore, be considered in conjunction with corresponding surface shape measurements in the assessment of brace treatment of scoliosis.

Allograft versus autograft bone in scoliosis surgery.

The results of a study of the use of autograft versus allograft bone in the surgery of idiopathic adolescent scoliosis are presented. Two groups of patients, matched for age, sex, level and angle of curve, received bone grafts, 20 patients having autogenous bone from the iliac crest and the other 20 having donor bone from a bone bank. Both groups had otherwise identical posterior fusions and Harrington instrumentation. There was no difference between the two groups in a blind, radiographic assessment of bone graft mass at six months, nor in maintenance of the curve correction over the same period. No major operative complications nor failures of instrumentation were encountered. There was, however, a marked reduction in operative time and blood loss in the patients receiving donor bone and also a much lower incidence of late symptoms relating to the operative sites. We conclude that, even in the presence of adequate iliac crest, the use of bank bone is superior for grafting in idiopathic scoliosis surgery.

ISIS scanning: a useful assessment technique in the management of scoliosis.

The value of surface topographical measurements in the assessment of curve progression in adolescent idiopathic scoliosis is demonstrated in a group of 51 patients. Cobb angles at the commencement of the study ranged from 10 degrees -55 degrees (mean 34.5 degrees), and the mean follow-up period was greater than 2 years. The surface shape method correctly identified curve evolution in 84% of the patient group. Of these, the eight patients who underwent spinal instrumentation were correctly predicted as candidates for surgery.

Scoliosis surgery and its effect on back shape.

Thirty-four patients with adolescent idiopathic scoliosis were assessed by radiography and the integrated shape imaging system (ISIS) both before and after spinal surgery. Twenty-seven patients underwent Harrington instrumentation, after which lateral indices of curvature were significantly improved, but changes in the transverse plane were less pronounced. Sublaminar wiring was carried out in two patients whose thoracic lordosis was corrected by the surgery. Five patients whose severe deformity had persisted after previous spinal surgery underwent costoplasty, which resulted in a significant improvement in back shape measurements. We conclude that the cosmetic deformity of the back in scoliosis is only partially corrected by operations on the spine itself, whilst costoplasty addresses the problem directly, and improves the surface shape.

A method for analysis of back shape in scoliosis.

The shape of the back is an important factor in the clinical assessment of various spinal disorders, in particular scoliosis. A method of analysis of back surface shape is described which was designed to present most of the numerical parameters needed to assess the progress of the disease as it affects body shape. Measurements of back surface shape and manually marked anatomical landmarks were taken from a television/computer surface measurement system in which a plane of light was scanned over the back and from moiré topographs. The anatomical landmarks were used to define reference planes from which successive analyses were matched. Asymmetry in the transverse plane was illustrated by horizontal cross-sections and skin surface angles. The lateral deformity was shown by an estimate of the line of the vertebral bodies beneath the skin, derived by adding an extra lateral displacement to the palpated positions of the spinous processes, proportional to the rotation of the skin in the transverse plane. This model was used to estimate vertebral end-plate angles and Cobb angles. Lateral sections showed kyphosis and lordosis. Correlations of Lateral Asymmetry from the surface shape analysis with Cobb angle from X-ray measurements in three groups of patients (totalling 119 subjects) were in the range r = 0.77 to r = 0.94, p less than 0.0001. The analysis has reduced follow-up X-ray examinations at the Nuffield Orthopaedic Centre because it indicates quantitatively and with complete safety both lateral asymmetry and deformity in the transverse plane.

Cadaveric study comparing the stability of upper distraction hooks used in Harrington instrumentation.

Many different designs of upper distraction hooks for use in Harrington instrumentation are available. There is no published evidence to date to support the use of one hook in preference to another. This study compares the distraction force required to dislodge the three most commonly used designs of Harrington upper distraction hook. In cadavers the force required for failure of the plain, ribbed, and bifid hooks was compared as were the modest of vertebral fracture at the time of cut out. The bifid hook required a significantly greater distraction force to fracture the lamina, and the pattern of fracture was more extensive than it was with the plain or ribbed hooks.

Vertebral motion measured using biplanar radiography before and after Harrington rod removal for unstable thoracolumbar fractures of the spine.

The use of Harrington distraction rods for stabilization of fracture dislocation of the thoracolumbar spine is well established. For better initial stabilization and later return of flexibility we routinely use a long rod but fuse over a short segment and then remove the rods at 1 year. A biplanar radiographic technique was used to assess vertebral motion both before and after removal of Harrington rods in five patients. The investigation showed the rod acted to restrict movement and relieved loads on the spine that they spanned. Although all the patients regained considerable spinal flexibility once the rods were removed, none of the intervertebral joints measured could be considered solidly fused. However, the pattern of movement remained abnormal 6 months after rod removal with many intervertebral joints exhibiting lateral flexion and axial rotation during voluntary flexion extension. Despite this, a long rod/short fuse stabilization with routine rod removal after 1 year combines the initial advantage of operative stabilization and is shown to allow a return of spinal flexibility subsequently.

The periosteum in growth plate failure.

To investigate the periosteal contribution to the integrity of the growth plate, the authors subjected the proximal tibias of 110 male and female Sprague-Dawley rats between the ages of 25 and 65 days to axial and perpendicular forces to produce epiphysiolysis by use of a slow-loading technique and a cross-head speed of 10 mm per minute. Paired tibias of each rat were loaded under identical conditions, the only difference being the presence or absence of an intact periosteum. Mean values of body weight, tibial length, and cross-sectional areas of the growth plate after epiphysiolysis showed a linear increase with the age of the rat. No significant differences at the 5% level were observed in the tibial length and cross-sectional areas of the paired tibias. However, a consistently higher force was needed to produce epiphysiolysis with the periosteum intact. This was significant at all ages in both axial and perpendicular loading but was marked for young rats aged 45 days and under that were subjected to axial loading, where the level of significance was less than 1%. Calculated stress values showed a similar significant trend. The periosteum contributes significantly to the stiffness of the system, as shown by typical load deformation curves, and if it is divided, the gradient of the curve is clearly reduced up to epiphysiolysis. All periosteal fibers are not recruited in resisting a perpendicular force. Histologic examination of the specimens showed two patterns of failure corresponding to axial and perpendicular loading and also showed the failure path.

Weight-relieving cast for comminuted os calcis fractures--a preliminary report.

A patellar-tendon-bearing, weight-relieving cast is described. This allows early walking by patients with comminuted fractures of the os calcis and is especially useful for bilateral fractures.

Undergraduate education in the accident unit.

The present system of undergraduate education in trauma has evolved over the past 15 years. As with orthopaedic teaching in Oxford (Dickson, Houghton & Duthie, 1979) an intensive 4-week course is provided for small groups of students. The subject is covered by personal teaching illustrated by practical problems together with a basis of seminars and tutorials.