Deformity surgery is planned using the CORA method. The Taylor Spatial Frame^¯ is a six-axis deformity correction device in which this method can be put to use through the web-based software. Until recently there was no way of planning the correction with a computer. This was done with standard radiographs with the help of pencils, rulers and protractors or a linefinder^¯. Orthocrat^¯ has developed a piece of software that can plan the deformity correction from 2 orthogonal radiographs which can be imported into the computer via a PACS server as a DICOM image or as a JPEG. A Taylor Spatial Frame was programmed with a 5 degree valgus angle, with and without using the web based software in a chronic deformity mode of correction. The deformities were then analysed on paper with a linefinder and with the SpatialCAD^¯ software. The measured deformities were programmed into the web-based software in Total Residual Mode. The final frame configuration was then established based on the initial frame parameters. The programming based on the SpatialCAD^¯ software gave a more accurate result than the linefinder technique.

The SpatialCAD^¯ software is a useful tool for the planning of deformity correction with the Taylor Spatial Frame^¯. It is especially useful when the frame is mounted off the orthogonal axis of the limb or the frame is radiographed out of the plane of the reference ring. Interestingly the results showed that the accuracy of the deformity correction was much better when radiographs were taken in the plane of the reference ring using SpatialCAD, whereas the deformity correction was no more accurate with the linefinder method when comparing planar and non-planar radiographs.

Background

Paediatric pelvic corrective surgery for developmentally dysplastic hips requires that the acetabular roof is angulated to improve stability and reduce morbidity. Accurate bony positioning is vital in a weight-bearing joint as is appropriate placement of metalwork without intrusion into the joint. This can often be difficult to visualise using conventional image intensifier equipment in a 2D plane.

Modern methods of deformity correction such as the Taylor Spatial Frame (TSF) allow correction of deformities to within tolerances of 1° and 0.5mm. Plain X-radiography using orthogonal views is the current standard for the assessment for the evaluation of angular limb deformities. CT has been used for the assessment of torsional and axial deformities but its use has not been described for the measurement of angular deformities. Furthermore, dedicated correction planning software (SpatialCad™) may allow more accurate deformity definition.

This study aims to evaluate the accuracy of CT and SpatialCad™ to measure angular deformities in vitro. A tibia sawbone was coated in radio-opaque paint. A TSF was mounted on it and an osteotomy made in the mid-diaphyseal region. Four deformities were created and imaged with plain radiography and CT. Four observers measured the deformities using paper and pencil, PACS and SpatialCad™ for plain radiographs and Spatial-Cad™ for the CT scout views. The variance of the mean response of observed differences between main treatment factors was measured using analysis of variance.

There was no significant difference in variability (precision) between observers or methods of measurement. However, measurements made with PACS and Spatial-Cad™ on plain radiographs, but not CT scout views, were also accurate.

There does not appear to be any evidence at present that the use of CT for measurement of angular limb deformity is justified over plain radiography. Spatial-Cad™ is designed to optimize deformity correction planning for use with TSF, but PACS appears to be adequate for use with other deformity correction systems.

Universal neonatal screening of developmental dysplasia of the hip (DDH) remains controversial and a few centres have adapted this practice in the United Kingdom. Our institute has established a DDH screening programme over the last 19 years. The following shows our result after a recent change in our screening programme protocol. All infants born in Coventry are screened for DDH by a clinical examination and ultrasound scan (USS). 5,084 babies were born over a 12-months period. Normal examination and USS were detected in over 90% of the cases. Abnormality detected through either clinical examination or USS was referred to a special orthopaedic/USS clinic.

However, in the majority of the cases, subsequent assessments were normal and only 23 babies required treatment. In these cases, the majority had not shown any signs of clinical abnormality. However, serial USS had shown persistent abnormality of at least Graf grade II or higher. The average time from birth to a treatment with a Pavlik Harness was 35 days and the average duration of a treatment was 48 days. Apart from one case, all the babies were treated successfully. The unsuccessful cases had a Graf grade IV at the presentation and had shown no sign of improvement on sequential USS. No complications were noted.

While the sensitivity of detecting DDH through clinical examination remains poor, USS has become an essential tool in our screening programme. Many initial abnormalities are secondary to hip immaturity and they tend to resolve. Those with clinical instability and persistent USS Graf grade II or higher should be treated with early Pavlik Harness. Early detection has led to better results than late diagnosis, and in addition to this, the overall number of operations required could be reduced. Yet, the need for a major surgical intervention has been all but eliminated.

Universal neonatal screening of developmental dysplasia of the hip (DDH) remains controversial and a few centres have adapted this practice in the United Kingdom. Our institute has established a DDH screening programme for many years. The following shows our result after a recent hospital relocation and changes to the screening programme.

All infants born in Coventry are screened for DDH by a clinical examination and ultrasound scan (USS). 5,084 babies were born over a 12-months period. Normal examination and USS were detected in over 90% of the cases. Abnormality detected through either clinical examination or USS was referred to a special orthopaedic/USS clinic. However, in the majority of the cases, subsequent assessments were normal and only 23 babies required treatments. In these cases, the majority had not shown any signs of clinical abnormality. However, serial USS had shown persistent abnormality of at least Graf grade II or higher. The average time from birth to a treatment with a Pavlik Harness was 35 days and the average duration of a treatment was 48 days. Those with Graf III or higher at initial presentation, but spontaneous reduced without treatment were follow-up to one year. The acetabular index in these cases was normal. Apart from one case, all the babies were treated successfully. The unsuccessful cases had a Graf grade IV at the presentation and had shown no sign of improvement on sequential USS.

While the sensitivity of detecting DDH through clinical examination remains poor, USS has become an essential tool in our screening programme. Many initial abnormalities are secondary to hip immaturity and they tend to resolve. Those with clinical instability and persistent USS Graf grade II or higher should be treated with early Pavlik Harness. Early detection has led to better results than late diagnosis, and in addition to this, the overall number of operations required could be reduced.

Pre-operative planning for limb deformity correction involves detailed imaging of the lower limb to define the level, magnitude and direction of deformity. This is then used to plan the correction by defining the centre of rotational alignment (CORA). The method as described by Paley and Hertzenberg involves the use of orthogonal radiographs of the lower limbs using long cassettes (130 cm) taken from a distance of 305 cm to minimize magnification. This method requires special equipment, trained radiographers and multiple doses of radiation even when each radiograph was perfectly positioned first time every time.

We present a work in progress replacing the radiographs with a “virtual 3D” CT dataset of the lower limb which we hope will improve the ability to pre-operatively plan deformity correction, but at a lower cost in terms of skill, equipment and dose. Whole limb CT is too costly in terms of time and radiation dose for this to be suitable. New multislice CT systems allow a single coherent study to include segments of unscanned data. Thus it is possible to run a single series through a lower limb to include the articular surfaces, but excluding the diaphyseal segments (gaps). This reduces the radiation exposure to the patient. Such data when entered into suitable DICOM image manipulation software allows the Radiologist or Surgeon to measure and assess the deformity with great precision. Such software is available on the diagnostic radiology workstations but is also available for personal computers, allowing the Surgeon to perform preoperative planning in a numerical modeling setting. Allowing the elements of length, rotation, translation and angulation of the deformity to be measured and corrective surgery tested on the mathematical model.

We have compared the measurements taken from a deformity model using this new CT approach and compared it to standard radiographs and found that the above method is no less accurate. Rotational deformities are easier to estimate. However the advantage of our method is that the dataset can be manipulated to determine other technical aspects of deformity correction such as calculating the mounting parameters of the Talyor Spatial Frame.

We present worked examples of the methodology showing how this technique improves deformity appraisal.

Introduction: The UMEX system of external skeletal fixation has been widely used on the Indian subcontinent since its development by Dr. B.B. Joshi of Mumbai. The system employs a method of gradual distraction with manual correction of deformity. It has applications to both the upper and lower limbs, both in Orthopaedic and Traumatic conditions.

This paper aims to introduce the system to members of B.S.C.O.S. as an alternative method of correction of the relapsed clubfoot. It has a use in other Paediatric and Adult foot deformities.

The system is light and easy to apply, and unlike some other methods of external fixation is cheap and well tolerated by patients and their parents.

Results: This paper will describe the use of the device in the first 3 patients with club foot and with 2 others, one with deformity secondary to neurological abnormality, one patient with congenital abnormality of the forefoot.

The assessment of deformity in club foot is controversial and difficult to apply to many cases. The goal of treatment is a plantigrade and supple foot, that functions well in locomotion. To date, admittedly in a small number of cases, this has been achieved following relapse from earlier surgery.

Discussion: The management of relapsed club foot and other complex foot deformities is often far from easy, and results in a stiff foot, with some residual deformity evident after repeated surgery. The UMEX system, by combining distraction with gentle manual correction, has, in our hands, been effective in restoring shape and function to the foot without the need for invasive surgery.

Introduction and Aims: To determine the optimum management of growth arrests secondary to meningococcal septicaemia.

Method: A retrospective study of 28 children treated in children’s hospitals in the UK for long bone deformities caused by growth plate arrests secondary to meningococcal septicaemia.

Results: 28 children (age range four to eight years) with growth arrests of the long bones following meningococcal septicaemia were treated for their bony deformities (a limb length discrepancy or a progressive angular deformity of the upper or lower limb) using the Ilizarov technique. Resection of bony blocks was ineffective in preventing progressive deformities. Limb length discrepancies were treated satisfactorily with equalisation of limb lengths. Angular deformities required ablation of the remaining part of the affected growth plate in order to prevent recurrence. Distal tibial deformities were treated satisfactorily with a transepiphyseal osteotomy. In the upper limb lengthening of either the radius or ulna restored alignment to the wrist. One patient with a growth arrest affecting a tibial amputation stump underwent satisfactory stump realignment and lengthening. Limb lengthening will need to be repeated in younger children, as the deformity will recur with growth until skeletal maturity.

Conclusion: The Ilizarov technique enables satisfactory treatment of growth deformities secondary to meningococcal septicaemia. With peripheral growth plate arrests causing an angular deformity the remaining open growth plate needs to be ablated to prevent recurrence of the angular deformity. Any recurrence will then be a shortening only, which can be treated by further lengthening if required.