James Hunter

EARLY FEMORAL LOOSENING IN ONE DESIGN OF CEMENTED HIP REPLACEMENT

We have studied aseptic loosening of the femoral component in 76 patients with primary total hip replacement using the Capital prosthesis. The mean follow-up was 26 months (10 to 37). Twelve femoral components (16%) were definitely and eight (10%) were possibly loose. They were characterised by a thin cement mantle (p < 0.001) and excessive residual cancellous bone in the proximomedial region (p < 0.01). We recommend that the cement mantle around the prosthesis should be 2 to 3 mm and that further long-term studies are needed to evaluate the wear properties of titanium-nitride-coated titanium femoral heads.

Development and validation of the AO pediatric comprehensive classification of long-bone fractures by the Pediatric Expert Group of the AO Foundation in collaboration with AO Clinical Investigation and Documentation and the International Association for Pediatric Traumatology

A series of four agreement studies (classification sessions) were conducted to support the development and validation of a comprehensive pediatric long bone fracture classification system. This system follows the principle of the Müller-AO classification for long bones in adults and integrates most relevant existing pediatric classification systems. The diagnosis includes the distinction between epiphyseal (E), metaphyseal (M), or diaphyseal (D) fractures, as well as identification of child-specific features. This article describes the proposed system in some detail. Digital standard preoperative anteroposterior and lateral radiographs from 267 consecutive pediatric patients (<16 years old and open physis) with single fractures of the distal humerus, radius, or tibia were collected at a single university childrens hospital. Fractures were classified independently by five experienced pediatric surgeons. The classification process was assessed for reliability using the kappa coefficient and accuracy using latent class modeling separately for each bone for bone type, and separately for each bone type for child codes. At the last classification session, kappa values for E-M-D and child code classifications were mostly above 0.90, and accuracy estimates were between 75% and 100% for different surgeons, types, and bones. Disagreement and misclassification of fractures were overall very low; hence, experienced and trained surgeons can classify pediatric long bone fractures using the proposed system with high accuracy based on standard radiographic views. The authors encourage wide consultation and further evaluation of this proposed pediatric long bone classification system with a larger number of future users with different training before being used for documentation and clinical studies.

Interventions for treating wrist fractures in children

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects (benefits and harms) of interventions for common distal radius fractures in children, including skeletally immature adolescents.

The posterolateral approach to the distal humerus for open reduction and internal fixation of fractures of the lateral condyle in children

Our study describes a posterolateral approach to the distal humerus for open reduction and internal fixation of displaced fractures of the lateral condyle. A total of 20 patients had open reduction and internal fixation over a four-year period using this approach, and at a mean follow-up of 12 months had full union, range of movement and no complications, either clinical or radiological. This approach is well suited to the exact visualisation and accurate reduction of this difficult fracture with minimal dissection of tissues.

Development and Evaluation Process of a Pediatric Long-Bone Fracture Classification Proposal

Background and Purpose:A pediatric long-bone fracture classification proposal was developed following the principle of the Müller AO classification long bones for adults and assessed for reliability and accuracy in a series of four pilot agreement studies (classification sessions).Material and Methods:Six surgeons independently classified 136 radius fractures using digitalized radiographs. Reliability and accuracy were quantified using Kappa and Latent Class Modeling, respectively.Results:Results from the last two sessions are presented whereby fractures were classified as epiphyseal, metaphyseal or diaphyseal. In session 3, the overall Kappa was 0.78 and pairwise Kappa ranged between 0.74 and 0.95. Surgeons were overall 85.7–99.5% accurate. In session 4, the overall Kappa was 0.98 and pairwise Kappa ranged between 0.95 and 0.99. Surgeons were overall 98.8–99.5% accurate.Conclusion:The systematic implementation of pilot agreement studies and use of Latent Class Modeling methodology for the development and evaluation of fracture classification systems in orthopedics are encouraged.

End caps prevent nail migration in elastic stable intramedullary nailing in paediatric femoral fractures: a biomechanical study using synthetic and cadaveric bones

End caps are intended to prevent nail migration (push-out) in elastic stable intramedullary nailing. The aim of this study was to investigate the force at failure with and without end caps, and whether different insertion angles of nails and end caps would alter that force at failure. Simulated oblique fractures of the diaphysis were created in 15 artificial paediatric femurs. Titanium Elastic Nails with end caps were inserted at angles of 45°, 55° and 65° in five specimens for each angle to create three study groups. Biomechanical testing was performed with axial compression until failure. An identical fracture was created in four small adult cadaveric femurs harvested from two donors (both female, aged 81 and 85 years, height 149 cm and 156 cm, respectively). All femurs were tested without and subsequently with end caps inserted at 45°. In the artificial femurs, maximum force was not significantly different between the three groups (p = 0.613). Push-out force was significantly higher in the cadaveric specimens with the use of end caps by an up to sixfold load increase (830 N, standard deviation (SD) 280 vs 150 N, SD 120, respectively; p = 0.007). These results indicate that the nail and end cap insertion angle can be varied within 20° without altering construct stability and that the risk of elastic stable intramedullary nailing push-out can be effectively reduced by the use of end caps.

An Isolated Articular Surface Fracture of the Distal Patella: An Unusual and Previously Unreported Paediatric Injury

Paediatric patella fractures are uncommon, accounting for less than 1% of all paediatric fractures. This case report describes a previously undocumented patella fracture in a child, with a clear mechanism of injury. We present a case of a previously healthy 14-year-old boy who fell directly onto his right knee after coming off his pushbike. He sustained an isolated fracture involving the articular surface of the distal part of the patella with minimal displacement. The patient was managed conservatively in a Richard splint for three weeks, followed by a knee brace with gradually increasing degrees of flexion. He was instructed to be nonweight bearing for two weeks and then partial weight bearing for six weeks. At the final followup, after 9 weeks, the patient had full return of function and standard radiographs show the fracture to be healed. This case report has demonstrated how direct compression to the paediatric patella can cause a fracture isolated to its articular surface. It has detailed the natural progression of this injury to radiographic union, using a conservative management strategy. The authors believe that this case report provides an interesting insight into the variation of paediatric patella fractures and their contrasting management strategies.

Recognising contributions to work in research collaboratives: Guidelines for standardising reporting of authorship in collaborative research

BACKGROUND Trainee research collaboratives (TRCs) have been revolutionary changes to the delivery of high-quality, multicentre research. The aim of this study was to define common roles in the conduct of collaborative research, and map these to academic competencies as set out by General Medical Council (GMC) in the United Kingdom. This will support trainers and assessors when judging academic achievements of those involved in TRC projects, and supports trainees by providing guidance on how to fulfil their role in these studies. METHODS A modified Delphi process was followed. Electronic discussion with key stakeholders was undertaken to identify and describe common roles. These were refined and mapped to GMC educational domains and International Committee of Medical Journal Editors authorship (ICJME) guidelines. The resulting roles and descriptions were presented to a face-to-face consensus meeting for voting. The agreed roles were then presented back to the electronic discussion group for approval. RESULTS Electronic discussion generated six common roles. All of these were agreed in face-to-face meetings, where two further roles identified and described. All eight roles required skills that map to part of the academic requirements for surgical training in the UK. DISCUSSION This paper presents a standardised framework for reporting authorship in collaborative group authored research publications. Linkage of collaborator roles to the ICMJE guidelines and GMC academic competency guidelines will facilitate incorporation into relevant training curricular and journal publication policies.

Biomechanical investigation of two long bone growth modulation techniques by finite element simulations

Implants used to correct pathological varus–valgus deformities (VVD) and leg length discrepancies (LLD) may not be optimized for the specific treatment, as suggested by their off‐label use. Detailed analysis of this issue has been limited by the poorly understood mechanical behavior of the growing physis and ignorance of the loads acting on the implants. The aim of this study was to predict and compare the loading conditions of a growth modulation implant in VVD and LLD treatments. Idealized finite element (FE) models of the juvenile distal femur treated with the Eight‐Plate implant were developed for VVD and LLD. Bone growth was simulated using thermal strains. The axial force in the plate was compared between the two treatments. Case‐specific plate forces were predicted by virtually reproducing the screw deformation visible on radiographs of LLD (N = 4) and VVD (N = 4) clinical cases. The simple FE models reproduced the clinical implant deformations well. The resulting forces ranged from 129 to 580 N for the VVD patients. For LLD, this range was from 295 to 1002 N per plate, that is, 590–2004 N for the entire physis. The higher forces in LLD could be explained by restricted screw divergence in the double‐sided implant application. For the first time, the loading conditions of a growth modulation implant were investigated and compared between two treatments by FE analyses, and the range of case‐specific loads was predicted. These simulation tools may be utilized for guiding appropriate usage and for efficient development of implants.

Implementing an electronic patient handover system.

BACKGROUND Clear communication among health-care teams is paramount for safe patient care and effective handover. Advances in information technology have led to an increased use of electronic systems within modern health care. This quality improvement project introduced an electronic patient handover system that was intended to improve the accuracy of patient handover lists and be readily available to all members of the health-care team. METHODS A quality improvement project was undertaken to assess the effect of introducing an electronic patient handover system on maintenance workload and list accuracy. RESULTS List errors were common before the introduction of the electronic patient handover system, commonly patient location or a patient being incorrectly omitted from the list. These errors decreased significantly after the introduction of the electronic system (P<0.005 and 0.04 respectively). The workload associated with its maintenance also decreased (P<0.005) because many data fields were pre-populated by the software. This resulted in fewer instances of patients being missed on ward rounds (P<0.04). CONCLUSIONS Through modifying existing information technology infrastructure, a centrally maintained, widely accessible electronic handover system was introduced. This reduced the workload associated with maintaining handover lists and the rate of errors.