1. Congenital vertical talus is described and the criteria for diagnosis are emphasised. The need for its distinction from other forms of convex pes valgus is stressed. 2. The operative technique of Stone for Lloyd-Roberts (1963) is detailed and the results of seven such operations are examined. 3. Departure from the technique in any respect has resulted in an unsatisfactory outcome, whereas stringent observation of the operative details has resulted in uniformly good results in four patients. 4. Certain aspects of diagnosis, differential diagnosis, etiology, pathology and surgical management are discussed, together with a review of some of the relevant literature

In a consecutive series of 124 children with spina bifida we found that 220 (89%) of the 248 feet were deformed: 70 had a calcaneus deformity; 126 were in equinus; 16 were in valgus; 3 were in varus; and 5 had convex pes valgus. Operations were performed on 171 (78%) of the deformed feet. Spasticity of the muscles controlling the foot was detected in 36 (51%) of the 70 calcaneus feet and in 22 (17%) of the 126 equinus feet. The deformities were symmetrical in 94 children. There is a high incidence of foot deformity in patients with spina bifida who have no voluntary activity in the motors of the feet

1. The prognosis of paralytic scoliosis has been studied by defining curve patterns and establishing the natural development as seen in fully grown patients who have not had surgical correction. 2. The prognosis, unlike that in idiopathic scoliosis, is related to the age of onset of the curvature and the degree of muscle imbalance rather than the site of the primary curve. 3. Paralysis of limb muscles is shown to be unrelated to the development of scoliosis. The intercostal muscles and the lateral abdominal flexors produce scoliosis when weaker on the convex side of the curve. Gravity and the other trunk muscles certainly play a part in the development of lumbar curves but their importance is difficult to assess

A series of 98 patients with juvenile idiopathic scoliosis have been analysed. This showed that between the ages of four and six there was a higher incidence in boys whereas between seven and nine years of age, the proportion of girls was higher. Regardless of sex and age the majority of the curves were convex to the right and the single thoracic curve was the commonest pattern. Spontaneous resolution occurred in seven patients: in four the curves resolved within two years; in the three others the curves resolved in three, four and five years respectively. Forty-four per cent of all patients were managed conservatively and in 56 per cent spinal fusion was carried out

Aims

In our unit, we adopt a two-stage surgical reconstruction approach using internal fixation for the management of infected Charcot foot deformity. We evaluate our experience with this functional limb salvage method.

Experimental evidence has accumulated in recent years to suggest that scoliosis can be caused by asymmetrical spinal muscle weakness due to sensorineural loss, though this suggestion has not achieved universal acceptance. The evidence is supported by histopathological observations on cases of clinical idiopathic scoliosis. A study is presented in which cynomolgus monkeys had one, two or three dorsal spinal nerve roots cut. Scoliosis developed, convex to the damaged side; its severity was dependent on the number of nerve roots cut. Section of the first lumbar dorsal spinal nerve root had a marked tendency to cause scoliosis. The study supports the view that scoliosis may be caused by asymmetrical paraspinal muscle weakness acting through loss of proprioception

A review is presented of 13 young patients with congenital scoliosis who were treated by epiphysiodesis of part of the vertebral bodies combined with posterior fusion, both on the convex side; the plan was to arrest growth on the convexity which, combined with growth of the concave side, would result in progressive correction of the curve. The first patient was operated on at the age of four years and has now reached skeletal maturity with complete correction of her curve. Several others, still growing, are showing progressive correction. Only three curves, in which kyphosis was more severe than scoliosis, have deteriorated since operation. Although full assessment must await skeletal maturity of all the patients, this approach appears to have sufficient potential to justify an early report

Rosette strain gauges were attached to the cranial and caudal aspects of the proximal half of the radius in eight skeletally mature female sheep; The sheep's radius has a slight cranially convex curvature. During walking it was deformed so that the cranial surface was subjected to tension aligned along the bone's lon axis, and the caudal surface to compression similarly aligned. The compressive strain on the caudal aspect of the bone was consistently larger (X 1-9) than the tensile strain on the cranial aspect. The thickness of the cortex did not reflect this difference but in younger animals the process of osteonal remodelling seemed further advanced in the cortex which was customarily subject to the larger deformation. The relevance of these findings is discussed in relation to the technique of internal fixation and to our understanding of the basis of the mechanical adaptability of bone

We performed a prospective study using MRI in 16 consecutive infants with a mean age of 5.2 months (2.7 to 8.7) who had shown inadequate recovery from an obstetric lesion of the brachial plexus in the first three months of life, in order to identify early secondary deformities of the shoulder. Shoulders were analysed according to a standardised MRI protocol. Measurements were made of the appearance of the glenoid, glenoid version and the position of the humeral head. The appearance of the glenoid on the affected side was normal in only seven shoulders. In the remainder it was convex in seven and bioconcave in three. The degree of subluxation of the humeral head was significantly greater (p = 0.01) in the affected shoulders than in normal shoulders (157° v 170°). The presence of an abnormal appearance of the glenoid, retroversion of the glenoid and subluxation of the humeral head increased with age. There was a statistical difference (p = 0.05) between infants younger than five months and those who were older

Although a variety of techniques have been used with varying success to induce scoliosis in animals, primates have rarely been used. A series of monkeys is presented where scoliosis developed incidentally during the routine virulence testing of live, attenuated, oral poliomyelitis vaccines by intraspinal injection. The site and extent of histological damage in the different anatomical areas of the spinal cord were examined in 25 scoliotic monkeys and 25 matched controls. Analysis of the data demonstrated that there was significantly greater damage on the convex side of the spinal cords of the scoliotic animals, particularly in the sensory areas-the posterior horn and Clarke's column. Scoliosis was not thought to be caused by clinical poliomyelitis as the involvement of the anterior horn was not significantly greater than in the scoliotic animals than in the controls. These observations are taken to support the view that scoliosis may develop as a result of asymmetrical weakness of the paraspinal muscles due to the loss of proprioceptive innervation

1. The results of 243 thoracoplasty operations are discussed. It was found that scoliosis developed in over 99 per cent of cases and that the curve was convex towards the side of operation. The angle of curvature correlated closely with the number of ribs removed. 2. If the head, neck and tubercle of the rib and the transverse process of the corresponding vertebra were all removed the degree of scoliosis was increased, whereas if a thoracoplasty was performed with apicolysis and embedding of the scapula the spinal deformity was less. Possible explanations for these phenomena are discussed. 3. No evidence was found to support the theory of causation by imbalance between the paired "pneumatic cylinders" (lungs and thoracic cage) supporting the thoracic spine. 4. The scoliosis was found to progress for many years; some factors influencing this course are discussed. 5. No correlation was found between the age of the patient at the time of thoracoplasty and the degree of subsequent scoliosis, but severe spinal deformity can arise even in older adults

A radiological study of 50 patients with thoracic Scheuermann's disease revealed two types of lateral spinal curvature. A total of 43 lateral curves was present in 35 of the patients. Thirteen were apical at the same level as the Scheuermann's kyphosis and were due to vertebral-body wedging in the coronal plane; these curves had a mean Cobb angle of 15 degrees, occurred with equal prevalence in boys and girls and were directed equally to right and left. Thirty curves occurred in regions of compensatory lordosis (mean 5.6 degrees) situated above or, more commonly, below the Scheuermann's kyphosis. These scolioses had a mean Cobb angle of 16 degrees, were more often convex to the right than to the left and were significantly more prevalent in girls than in boys. The presence of these kyphoses and scolioses in the same spine, separated by only a few vertebrae, emphasises the importance of the sagittal plane in idiopathic spinal deformities and strongly suggests that idiopathic scoliosis and Scheuermann's disease share a common pathological process

We used a rabbit model to investigate the mechanism by which the angulation of fractures is corrected in children. We produced a transverse proximal tibial fracture in one leg of 12 eight-week-old New Zealand white rabbits and measured bone alignment and length and the patterns of bone growth and remodelling. The angle between the joint surfaces changed rapidly to correct the alignment of the limb as a result of asymmetrical growth of epiphyseal plates. In an adult with closed plates, the angle between the joint surfaces cannot therefore improve. The angle at the fracture itself showed slow improvement because of bone drift and the asymmetrical growth of the epiphyseal plates. Remodelling corrected the shape of the bone in the region of the fracture. Periosteal division on the convex side increased the growth of the epiphyseal plate on that side, thus slowing the correction. The effect was relatively small, providing an indication that factors other than the periosteum are important in inducing correction. External torsional deformities developed because of helical growth at the plate. This was probably caused by abnormal posture which induced a torque at the growth plate. Helical growth is the mechanism by which rotational deformities can occur and correct

Aims

To report mid- to long-term results of Oxford mobile bearing domed lateral unicompartmental knee arthroplasty (UKA), and determine the effect of potential contraindications on outcome.

Recent surveys have shown that idiopathic structural scoliosis of mild degree is generally not progressive. We will propose a mechanism which may be responsible for deterioration in the few. It has been observed that the spinal cord, although displaced towards the concavity, does not rotate in company with the vertebrae, thus exposing the emerging nerve roots to the effects of traction and possibly of entrapment. We suggest that progression occurs when the neuraxis is unable to adjust to the change in the anatomy of vertebral column. Our proposition is based upon our findings in a complete spinal column obtained from a baby with structural scoliosis. Support is provided by intercostal angiography, and by observations upon normal anatomy, the pathological anatomy of mature scoliotic spines and the anatomy of contrived scoliosis in normal spines. Although our histological and electrophysiological investigations are incomplete we can demonstrate a significant increase in degenerate cells in the dorsal root ganglia at the apex on the convex side. Lack of suitable necropsy material prevents us from confirming our observations so that our report is inevitably preliminary. We enter a plea that careful examination of the neuraxis be undertaken whenever a specimen of a scoliotic spine becomes available

We have used an experimental model employing the bent tail of rats to investigate the effects of mechanical forces on bones and joints. Mechanical strain could be applied to the bones and joints of the tail without direct surgical exposure or the application of pins and wires. The intervertebral disc showed stretched annular lamellae on the convex side, while the annulus fibrosus on the concave side was pinched between the inner corners of the vertebral epiphysis. In young rats with an active growth plate, a transverse fissure appeared at the level of the hypertrophic cell layer or the primary metaphyseal trabecular zone. Metaphyseal and epiphyseal trabeculae on the compressed side were thicker and more dense than those of the distracted part of the vertebra. In growing animals, morphometric analysis of hemiepiphyseal and hemimetaphyseal areas, and the corresponding trabecular bone density, showed significant differences between the compressed and distracted sides. No differences were observed in adult rats. We found no significant differences in osteoclast number between compressed and distracted sides in either age group. Our results provide quantitative evidence of the working of ‘Wolff’s law’. The differences in trabecular density are examples of remodelling by osteoclasts and osteoblasts; our finding of no significant difference in osteoclast numbers between the hemiepiphyses in the experimental and control groups suggests that the response of living bone to altered strain is mediated by osteoblasts

We report a study of the shapes of the tibial and femoral articular surfaces in sagittal, frontal and coronal planes which was performed on cadaver knees using two techniques, MRI and computer interpolation of sections of the articular surfaces acquired by a three-dimensional digitiser. The findings using MRI, confirmed in a previous study by dissection, were the same as those using the digitiser. Thus both methods appear to be valid anatomical tools. The tibial and femoral articular surfaces can be divided into anterior segments, contacting from 0° to 20 ± 10° of flexion, and posterior segments, contacting from 20 ± 10° to 120° of flexion. The medial and lateral compartments are asymmetrical, particularly anteriorly. Posteromedially, the femur is spherical and is located in a conforming, but partly deficient, tibial socket. Posterolaterally, it is circular only in the sagittal section and the tibia is flat centrally, sloping downwards both anteriorly and posteriorly to receive the meniscal horns. Anteromedially, the femur is convex with a sagittal radius larger than that posteriorly, while the tibia is flat sloping upwards and forwards. Anterolaterally, both the femoral and tibial surfaces are largely deficient. These shapes suggest that medially the femur can rotate on the tibia through three axes intersecting in the middle of the femoral sphere, but that the sphere can only translate anteroposteriorly and even then to a limited extent. Laterally, the femur can freely translate anteroposteriorly, but can only rotate around a transverse axis for that part of the arc, i.e., near extension, during which it comes into contact with the tibia through its flattened distal/medial surface as against its spherical posterior surface

Aims

This study aims to investigate the effects of posterior tibial slope (PTS) on knee kinematics involved in the post-cam mechanism in bi-cruciate stabilized (BCS) total knee arthroplasty (TKA) using computer simulation.

Aims

The Oswestry-Bristol Classification (OBC) was recently described as an MRI-based classification tool for the femoral trochlear. The authors demonstrated better inter- and intraobserver agreement compared to the Dejour classification. As the OBC could potentially provide a very useful MRI-based grading system for trochlear dysplasia, it was the aim to determine the inter- and intraobserver reliability of the classification system from the perspective of the non-founder.

1. Compression forces are mainly absorbed by the vertebral body. The nucleus pulposus, being liquid, is incompressible. The tense annulus bulges very little. On compression the vertebral end-plate bulges and blood is forced out of the cancellous bone of the vertebral body into the perivertebral sinuses. This appears to be the normal energy-dissipating mechanism on compression. 2. The normal disc is very resistant to compression. The nucleus pulposus does not alter in shape or position on compression or flexion. It plays no active part in producing a disc prolapse. On compression the vertebral body always breaks before the normal disc gives way. The vertebral end-plate bulges and then breaks, leading to a vertical fracture. If the nucleus pulposus has lost its turgor there is abnormal mobility between the vertebral bodies. On very gentle compression or flexion movement the annulus protrudes on the concave aspect–not on the convex side as has been supposed. 3. Disc prolapse consists primarily of annulus; it occurs only if the nucleus pulposus has lost its turgor. It then occurs very easily as the annulus now bulges like a flat tyre. 4. I have never succeeded in producing rupture of normal spinal ligaments by hyperextension or hyperflexion. Before rupture occurs the bone sustains a compression fracture. On the other hand horizontal shear, and particularly rotation forces, can easily cause ligamentous rupture and dislocation. 5. A combination of rotation and compression can produce almost every variety of spinal injury. In the cervical region subluxation with spontaneous reduction can be easily produced by rotation. If disc turgor is impaired this may occur with an intact anterior longitudinal ligament and explains those cases of tetraplegia without radiological changes or a torn anterior longitudinal ligament. The anterior longitudinal ligament can easily be ruptured by a rotation force and in my experience the so-called hyperextension and hyperflexion injuries are really rotation injuries. 6. Hyperflexion of the cervical spine or upper thoracic spine is an anatomical impossibility. In all spinal dislocations a body fracture may or may not occur with the dislocation, depending upon the degree of associated compression. In general, rotation forces produce dislocations, whereas compression forces produce fractures