Aims

Computer hexapod assisted orthopaedic surgery (CHAOS), is a method to achieve the intra-operative correction of long bone deformities using a hexapod external fixator before definitive internal fixation with minimally invasive stabilisation techniques.

The aims of this study were to determine the reliability of this method in a consecutive case series of patients undergoing femoral deformity correction, with a minimum six-month follow-up, to assess the complications and to define the ideal group of patients for whom this treatment is appropriate.

The aim of this study is to use a defined population of patients with meningococcal septicaemia to calculate the incidence of orthopaedic complications.

Medical records and radiographs were analyzed retrospectively for all patients admitted to the Paediatric Intensive Care Unit (PICU) of the Bristol Royal Hospital for Children from 01/01/2001 to 31/12/2012 with meningococcal septicaemia.

Of the 130 patients with meningococcal septicaemia alive at discharge, 10 developed orthopaedic sequelae, representing an overall incidence in this patient population of 7.7%.

9 patients required an amputation, mostly in the lower limb, 16/22 (72.7%). 48 growth plate abnormalities were identified in 8 patients. 39 (81.3%) The most commonly affected was the distal tibia (38.5%). 10 ankles were identified as having a varus malalignment. 6 patients had documented leg length discrepancy

Using a clearly defined denominator this study has identified an incidence of orthopaedic sequelae following meningococcal septicaemia of 7.7%.

The National Institute for Clinical Excellence (NICE) suggested that the incidence of growth disturbance is approximately 3%.

This study highlights the underestimation of orthopaedic complications following meningococcal septicaemia. Close follow up of at risk patients should be considered to reduce the potential impact of these debilitating injuries.

Predictions of lower limb growth are based upon historical data, collected from patients who had coexistent poliomyelitis. By utilising standardised longitudinal prospective European data, our objective was to generate superior estimates for the age and rate at which lower limb skeletal maturity is reached; thus improving the timing of epiphysiodesis, for the management of leg length discrepancy.

The Avon Longitudinal Study of Parents and Children of the 90s (ALSPAC) is a longitudinal cohort study of children recruited antenatally 2. Using a previously validated Multiplier Method, a sequence of leg length multipliers were calculated for each child.

15,458 individuals were recruited to the ALSPAC study; and of those whose growth was measured, 52% were boys and 48% girls, each with an average of eight recording episodes. 25,828 leg length multiplier (LLM) values were calculated with final recordings taken at a mean age of 15.5 years.

From this data, the age at which girls reach skeletal maturity (LLM=1) is 11 months later than previously calculated and for boys nearly 9 months earlier. With nearly 4000 more children recruited in this cohort than preceding studies, this study brings increased power to future leg length calculations.

Paley et al developed a mathematical model to predict height, using age, sex and current height. His predictions were based on growth charts from epidemiological databases, and then validated using 52 children. We looked at a recent large, local database, to assess whether the height multiplier is a reliable tool that can be used in clinical practice.

The Avon Longitudinal Study of Parents and Children of the 90s (ALSPAC) is a population based cohort study of 14, 000 contemporary British families. 5363 children had final height measured with an average of 10.5 additional height measurements. The height multiplier equation was defined as height at specific age divided by height at skeletal maturity.

No significant difference was observed between the mean results from Paley et al and the ALSPAC data. There was a significant range of results in the ALSPAC data, with a standard deviation of the multiplier of 0.08 for ages 7–15.

This large population study shows no significant difference between the historical databases Paley used and the more current European databases. The large range of results shown by the ALSPAC cast doubt on the clinical usefulness of individual results.

Meningococcal infection is the most common infective cause of death in children and causes significant morbidity in survivors.

Patients admitted to the Paediatric Intensive Care Unit (PICU) of the Bristol Royal Hospital for Children from 01/01/2001 to 31/12/2012 with a primary diagnosis of meningococcal septicaemia were reviewed.

A total of 10 (7.7%) of 130 patients developed orthopaedic complications. Those affected were significantly younger (p < 0.05), remained on PICU for longer (p < 0.001) and boys had a greater risk of developing orthopaedic complications (risk ratio: 3.1; 95% CI: 0.69–14.14). 9 patients required an amputation, 16/22 (72.7%) in the lower limb. Patient requiring amputation had multiple limb involvement. 48 growth plate abnormalities were identified in 8 patients, 39 (81.3%) in the lower limb, most commonly in the distal tibia.

This study has identified a high incidence of musculoskeletal morbidity. Close surveillance of these patients is recommended to identify growth arrest before the onset of clinically significant deformity. It identifies a defined population of patients with meningococcal septicaemia using admission to PICU as an entry criterion allowing accurate determination of the incidence and characteristics of the skeletal consequences of this condition.

Survivors of infantile meningococcal septicaemia often develop progressive skeletal deformity as a consequence of physeal damage at multiple sites, particularly in the lower limb. Distal tibial physeal arrest typically occurs with sparing of the distal fibular physis leading to a rapidly progressive varus deformity. Isolated case reports include this deformity, but to our knowledge there is no previous literature that specifically reports the development of this deformity and potential treatment options.

We report our experience of 6 patients (7ankles) with this deformity, managed with corrective osteotomy using a programmable circular fixator.

We investigated the effect of adjuvant and neoadjuvant chemotherapy regimens on the tibial regenerate after removal of the external fixator in a rabbit model of distraction osteogenesis using New Zealand white rabbits.

Forty rabbits were randomly distributed into two groups. In the neoadjuvant group, half of the rabbits received 1mg/kg cisplatinum & 2mg/kg adriamycin at eight weeks of age followed by 1mg/kg cisplatinum & 4mg/kg adriamycin at ten weeks of age. The remaining ten received an identical volume of normal saline using the same regimen. The adjuvant group differed only in the timing of the chemotherapy infusion. Half received the initial infusion ten days prior to the osteotomy, with the second infusion four days following the osteotomy. Again, the remaining ten rabbits received an identical volume of normal saline using the same regimen. This produced an identical interval between infusions and identical age at osteotomy in both groups. All rabbits underwent a tibial osteotomy at 12 weeks of age. Distraction started 24hours after osteotomy at a rate of 0.75mm a day for 10 days, followed by 18 days without correction to allow for consolidation of the regenerate.

At week 16 there was no difference in Bone Mineral Density (BMD), Bone Mineral Content (BMC) or volumetric Bone Mineral Density (vBMD) in the adjuvant group. Neoadjuvant chemotherapy appears to have a significant detrimental effect on BMD, vBMD and BMC. Despite this there were no significant alterations in the mechanical properties of the regenerate. Histologically there was a trend for increased cortical thickness in the control groups compared to intervention however this did not prove statistically significant.

In conclusion, adjuvant chemotherapy may be more beneficial for cases where distraction osteogenesis is being considered to replace segmental bone loss after tumour excision.

This study addresses the evolution of the orthopaedic management of patients with hypophosphatemic rickets, with the aim of providing skeletal mature aligned lower limbs, with minimal surgical insult.

Lower limb mal-alignment due to deformity is a significant cause of early degenerative change and dysfunction. Standard techniques are available to determine the centre of rotation of angulation (CORA) and extent of the majority of deformities, however distal femoral deformity is difficult to assess because of the difference between anatomic and mechanical axes. We found the described technique involving constructing a line perpendicular to a line from the tip of the greater trochanter to the centre of the femoral head inaccurate, particularly if the trochanter is abnormal. We devised a novel technique which accurately determines the CORA and extent of distal femoral deformity, allowing accurate correction.

Using standard leg alignment views of the normal femur, the distal femoral metaphysis and joint line are stylized as a block. A line bisecting the axis of the proximal femur is then extended distally to intersect the joint. The angle (θ) between the joint and the proximal femoral axis and the position (p) where the extended proximal femoral axis intersects the joint line are calculated. These measurements can then be reproduced on the abnormal distal femur in order to calculate the CORA and extent of the deformity, permitting accurate correction.

We examined the utility and reproducibility of the new method using 100 normal femora. θ = 81 ± sd 2.5°. As expected, θ correlated with femoral length (r=0.74). P (expressed as the percentage of the distance from the lateral edge of the joint block to the intersection) = 61% ± sd 8%. P was not correlated with θ.

Intra-and inter-observer errors for these measurements are within acceptable limits and observations of 30-paired normal femora demonstrate similar values for θ and p on the two sides.

We have found this technique to be universally applicable and reliable in a variety of distal femoral deformities.

Lower limb mal-alignment due to deformity is a significant cause of early degenerative change and dysfunction. Standard techniques are available to determine the centre of rotation of angulation (CORA) and extent of the deformities. However, distal femoral deformity is difficult to assess because of the difference between anatomic and mechanical axes. We describe a novel technique which accurately determines the CORA and extent of distal femoral deformity.

Using standard leg alignment views of the normal femur, the distal femoral metaphysis and joint line are stylised as a block. A line bisecting the anatomical axis of the proximal femur is then extended distally to intersect the joint. The angle (?) between the joint and the proximal femoral axis, and the position (p) where the extended proximal femoral axis intersects the joint line are calculated. These measurements can then be reproduced on the abnormal distal femur in order to calculate the CORA and extent of deformity, permitting accurate correction.

We examined the utility and reproducibility of the new method using 100 normal femora. We found this technique to be universally robust in a variety of distal femoral deformities.