Purpose

A review of the role of external fixators in paediatric trauma at The Royal London Hospital Trauma and Orthopaedic Department.

Although Bohler’s & Gissane’s angles are measured in adult calcaneal fractures, it is not known if such measurements are reliable in children nor how such measurements vary with the age of the child.

The Picture Archiving and Communications System (PACS) databases of 2 London Teaching Hospitals were searched and all children who had a lateral ankle xray taken as part of their attendance to the A& E department were identified. Films were excluded if there was a fracture of the calcaneus or if the film was oblique or of poor quality. Bohler’s and Gissane’s angles were measured using the image viewer software. All patients’ films were measured on two separate occasions and by two separate authors to allow calculation of inter- and intra-observer variation. Interclass Correlation Coefficients (ICC) were used to assess the reliability of the measurements.

347 children were identified and after exclusions, 218 films were used for the study. The overall ICC for Bohler’s angle inter-obsever error was 0.91 and for intra-observer error was 0.92, giving excellent correlation. This reliability was maintained across the age groups. Gissane’s angle inter-observer error was very poor and the intra-observer error poor across the age groups, although accuracy did improve as the patients approached maturity.

Further analysis of the Bohler’s angle showed a significant variation in the mean angle with age. Contrary to published opinion, the angle is not uniformly lower than that of adults but varies with age, peaking towards the end of the first decade before attaining adult values.

We feel that measurement of Gissane’s angle is unreliable in children but measurement of Bohler’s angle is accurate and reproducible. Bohler’s angle varies with age and knowledge of Bohler’s angle variation is important in the evaluation of os calcis fractures in children.

Introduction. Platelets play a central role in haemostasis and wound healing. We have used autologous Platelet Rich Plasma (PRP) to stimulate healing in a variety of cases. We would like to present our early experience with this technique.

Method. PRP is produced by centrifuging a sample of the patient’s blood. The volume of PRP produced is about 10% of the original volume. Thrombin, derived from the patient’s plasma, is mixed with the PRP to produce a platelet gel. This gel is semi-solid and makes the PRP more manageable intra-operatively. It can be used on its own, mixed with bone graft or de-mineralised bone matrix (DBM.)

Results. We have used platelet gel in 14 cases for a variety of clinical conditions. 57% were males and the mean age was 44.1 (range: 7–77.) Cases included 3 elective joint fusions, 7 non unions, 2 case of chronic osteomyelitis, 1 acute fracture and 1 pathological fracture. The gel was mixed with autologous bone graft in 10 cases, DBM in 1 case and used on its own in 3 cases. The number of cases is too small to make any comment on the rate of bone union. Some practical issues have arisen during the use of platelet gel.

Discussion. Is it better to give a large number of growth factors at slightly above background levels or a single growth factor millions of times above background level? This paper doesn’t answer that question but because wound and bone healing relies upon a cascade of growth factors, it is attractive to be able to provide many of these factors. Further studies are required to answer this fundamental question.

Introduction Biomechanical modelling of the human body requires measurement of the relative positions of skeletal elements. This information provides data on joint kinematics directly affects muscle attachment site locations and hence determines muscle moment calculations. Spinal orientation is particularly difficult to measure due to small joint movements and relative inaccessibility of the bones to direct measurement. This study presents a novel method of accurately determining relative bone position in vivo using magnetic resonance imaging (MRI).

Methods A process incorporating both positional and conventional MRI was used to determine the skeletal positions of the lumbar spine and pelvis. The method uses higher quality conventional MRI to determine bone geometries and then registers these with lower resolution, positional MRI images of various postures.

Using the positional scanner four postures were investigated: Neutral Standing, Neutral Sitting, Flexed Sitting and Extended Sitting. These scans comprised simultaneous sagittal and coronal non-contiguous slices to facilitate three-dimensional registration and reduce acquisition time. Conventional MRI was then used to scan the subject at higher resolution contiguous slices. After segmentation and surface extraction of all bones from all scans, each bone geometry was registered with each of the positional scans to produce high quality in vivo skeletal position data.

For 2 subjects, each of the 5 lumbar vertebrae and the pelvis were registered 5 times in the 4 postures to investigate intra-tester reliability. This resulted in 48 sets of 5 registrations. Each bone surface was represented by surface points and a local coordinate system. Angular and translational differences between coordinate axes were examined for each set of five registrations.

Results The results indicate good intra-measurer reliability with a maximum rotational difference for all vertebral registrations of less than 1 degree and a maximum origin translation of less than 3mm. The pelvic registrations demonstrated larger discrepancies. Flexion/extension, lateral bend and axial twist rotations were measured for each joint. While there did not appear to be patterns between the two subjects, there were obvious trends within each subject and in particular trends of lateral bending throughout sagittal plane motion were identified.

Discussion The results showed that the technique was able to register the surfaces reliably. The intervertebral movements between postures were within normal ranges of motion and demonstrated kinematic trends within an individual. At present, the greatest disadvantage of the method described lies in its large data processing times. The data collected are three dimensional and represent the anatomy and movement of a specific individual. The method can be used to examine joint mechanics and centres of rotation in three dimensions, validate the predictions of finite element models and investigate the effects of medical interventions.

Introduction: A review of the treatment of 33 open fractures in 29 children over the period 1997 to 2002.

Method: Intravenous antibiotics, debridement and wound irrigation was performed prior to skeletal stabilisation incorporating plaster cast immobilisation (4%), K wire fixation (13%), screw fixation (13%), flexible intramedullary nail fixation (13%) and external fixation (57%). Secondary wound closure was undertaken if appropriate at 48 hours. The tibia was involved in 49% of cases with approximately equal distribution of other long bone extremities. Fractures were classified according to Gustilo et al (22% grade I, 26% grade II, 17% grade III and 35% grade IIIb).

Results: The average age was 10 years in 22 boys and 7 girls. Tibial fracture union was an average of 9 weeks in gradeI and II compared with 20 weeks for grade III. The remaining fractures healed at an average of 10 weeks. Non union occurred in one patient (tibia). There was on case of growth arrest of the distal tibia. There were no cases of osteomyelitis.

Discussion: Open fractures in children most often result from high energy trauma. An increase in fracture and soft tissue severity is associated with a delayed union. Physeal injuries require close observation for potential growth arrest.

Lower limb fractures in children are common. These fractures can be managed in a variety of ways, and the method chosen depends on a number of factors including:

Age of the child.

Site of fracture.

Whether the fracture is open or closed.

Associated injuries.

Surgeon’s expertise and experience.

Parental wishes.

Femur: Immediate or early hip spica gives good results withminimal shortening particularly in the younger child. Flexible IM nails have been widely reported and give good results. It is important to appreciate the mechanics of how the nails function to stabilise the bone and to recognise that pre-bending the nails is a vital step in the operation. As surgeons become more confident in using the nails, the range of indications can be extended to include proximal or distal fractures, comminuted, open and pathological fractures.

Tibia: Skeletal stabilisation of open tibial fractures can be provided by application of an external fixator. The use of flexible IM nails in the tibia is more controversial. Introduction of these nails into the proximal tibia can be difficult and even with pre-bending of the wires, additional cast protection may be required.

Aims: To compare the cost of intra-medullary implants used stabilising paediatric diaphyseal fractures with the clinical outcome. Methods: Between March 1994 and August 2001, at two centres, The Womenñs and Childrenñs Hospital, Adelaide, Australia and The Royal London Hospital, London UK 60 children were surgically treated for diaphyseal forearm fractures using Elastic Stable Intramedullary Nails (ESIN) or 2.5mm Kirschner wires. Having established no difference in the clinical outcome or subjective disability of either technique we compared the implant cost directly. Results: The two treatments both resulted in an excellent outcome with all fractures leading to union with no subjective disability. The Kirscner wires cost £3.00 per wire while the ESI Nails cost between £57.50 and £ 113.30 per wire, depending on the dimensions. Conclusions: We were not able to demonstrate any difference in outcome between ESIN and K-Wiring, although the nails do offer theoretical advantages. The cost implications of using the special implant are twenty fold or more, and as the pressures of cost cutting grow, we wonder if theoretical advantage is Òvalue for moneyÒ.

Introduction: The majority of forearm fractures in children can be managed with a plaster cast alone and manipulation under anaesthetic as required. A small number of cases however require surgical intervention. A variety of methods are available but the use of elastic intramedullary nails is becoming the technique of choice.

Method: We present a two-centre study assessing the outcome of either Elastic StabJe Intramedullary Nails (ESIN) or Kirschner wires as the method of fracture stabilisation in diaphyseal forearm fractures of the radius and ulna.

Results: ESIN group: 24 children underwent ESIN fixation. There were 22 boys and 2 girls, mean age 9.4 years (1.4–15.2 years, p=O.ll). Indications for stabilisation included 21 cases for fracture instability (immediate or delayed,) 2 irreducible fractures and 1 open fracture. 14 children underwent surgery on the day they sustained their fracture. The remainder were operated on an average 6.5 days following injury (1–14 days). In the K wire group: 36 children underwent K-wires fixation with 2.5mrn wires. There were 21 boys and 15 girls, mean age 10.6 years (2.2–15.5 years). Indication for stabilisation included 22 cases for fracture instability , 6 irreducible fractures and 8 open fractures. 32 children underwent surgery on the day they sustained their fracture. The remaining 4 patients were operated on the following day.

Conclusions: All fractures united with no resultant subjective disability. The complication rate following K-wires was 16% and that following nail fixation 9%. Loss of forearm rotation was documented in 4 children in the K-wire group and 3 children stabilised with nails. These results confirm an excellent outcome following intramedullary fixation. We have demonstrated no difference in outcome between K-wires and ESIN, although the elastic nails do offer some theoretical advantages.