Compartment syndrome, a devastating consequence of limb trauma, is characterised by severe tissue injury and microvascular perfusion deficits. We hypothesised that leucopenia might provide significant protection against microvascular dysfunction and preserve tissue viability. Using our clinically relevant rat model of compartment syndrome, microvascular perfusion and tissue injury were directly visualised by intravital video microscopy in leucopenic animals. We found that while the tissue perfusion was similar in both groups (38.8% (standard error of the mean (. sem). 7.1). , 36.4. % (. sem. 5.7), 32.0% (. sem. 1.7), and 30.5% (. sem. 5.35) continuously-perfused capillaries at 45, 90, 120 and 180 minutes compartment syndrome, respectively versus 39.2% (. sem. 8.6), 43.5% (. sem. 8.5). , . 36.6% (. sem. 1.4) and 50.8% (. sem. 4.8) at 45, 90, 120 and 180 minutes compartment syndrome, respectively in leucopenia), compartment syndrome-associated muscle injury was significantly decreased in leucopenic animals (7.0% (. sem. 2.0), 7.0%, (. sem. 1.0), 9.0% (. sem. 1.0) and 5.0% (. sem. 2.0) at 45, 90, 120 and 180 minutes of compartment syndrome, respectively in leucopenia group versus 18.0% (. sem. 4.0), 23.0% (. sem. 4.0), 32.0% (. sem. 7.0), and 20.0% (. sem. 5.0) at 45, 90, 120 and 180 minutes of compartment syndrome in control, p = 0.0005). This study demonstrates that the inflammatory process should be considered central to the understanding of the pathogenesis of cellular injury in compartment syndrome. Cite this article: Bone Joint J 2015;97-B:539–43

Aims. Compartment syndrome results from increased intra-compartmental pressure (ICP) causing local tissue ischaemia and cell death, but the systemic effects are not well described. We hypothesised that compartment syndrome would have a profound effect not only on the affected limb, but also on remote organs. Methods. Using a rat model of compartment syndrome, its systemic effects on the viability of hepatocytes and on inflammation and circulation were directly visualised using intravital video microscopy. Results. We found that hepatocellular injury was significantly higher in the compartment syndrome group (192 PI-labelled cells/10. -1 . mm. 3. , standard error of the mean (. sem. ) 51) compared with controls (30 PI-labelled cells/10. -1 . mm. 3. , . sem . 12, p < 0.01). The number of adherent venular white blood cells was significantly higher for the compartment syndrome group (5 leukocytes/30s/10 000 μm. 2. , . sem 1. ) than controls (0.2 leukocytes/30 s/10 000 μm. 2. , . sem . 0.2, p < 0.01). Volumetric blood flow was not significantly different between the two groups, although there was an increase in the heterogeneity of perfusion. Conclusions. Compartment syndrome can be accompanied by severe systemic inflammation and end organ damage. This study provides evidence of the relationship between compartment syndrome in a limb and systemic inflammation and dysfunction in a remote organ. Cite this article: Bone Joint J 2016; 98-B:1132–7

The patella is a complex sesamoid bone within the quadriceps enhancing mechanical advantage of the extensor mechanism. Depending on activity, the patella magnifies either force or displacement; behaving as a lever, by redirecting quadriceps force it also acts as a pulley. Aim. We describe and validate a device for obtaining consistent dynamic weight bearing views of the patellofemoral joint (PFJ). Materials and Methods. Weight bearing (WB) axial views of 48 knees (24 patients) were performed using the device. The sulcus angle (SA), congruence angle (CA), lateral patellofemoral angle (LPFA), facet angle (FA) and patellofemoral displacement (PD) were measured. These were compared with similar measurements made on prone (PR) and axial (AX) radiographs of same knees. Results. Variance (V=SD2) and Standard error of mean (SEM/95% CI) for all measurements in each of the three views were analysed. For the Sulcus Angle, Congruence angle and LPFA, the WB view had the lowest SEM and the least variance in comparison to PR and AX views (SEM 1.05/V 30.14, SEM 2.52/V 172.39 and SEM 1.34/V 47.61 respectively for the SA, SEM 3.09/V 256, SEM 2.79/V 210.25 and SEM 3.37/V 306.25 respectively for the CA, SEM 0.67/V 11.9, SEM 1.20/V39.06 and SEM 1.03/V 28.83 respectively for the LPFA). SEM and Variance for FA measurements were similar for WB and AX views but superior to PR views (SEM 1.62/V 70.56, SEM 1.6/V 68.9 and SEM 2.3/V 148.84 respectively). Mean PFD was maximum on the WB view compared to the PR and AX views (36.0, −45.62 and 22.23 respectively) with lowest SEM and V (SEM 8.73/V 2052.0, SEM 18.65/V 92959.67 and SEM 9.70/V 2540.16 respectively). Conclusion. The WB view as introduced and reported here has consistently lower Variance, SEM and SD in comparison to Axial and Prone views for all measurements of the PFJ. WB view also gives a more accurate dynamic measure of Patello Femoral displacement. The view is easily obtained and readily reproduced

Limb-injury severity scores are designed to assess orthopaedic and vascular injuries. In Gustilo type-IIIA and type-IIIB injuries they have poor sensitivity and specificity to predict salvage or outcome. We have designed a trauma score to grade the severity of injury to the covering tissues, the bones and the functional tissues, grading the three components from one to five. Seven comorbid conditions known to influence the management and prognosis have been given a score of two each. The score was validated in 109 consecutive open injuries of the tibia, 42 type-IIIA and 67 type-IIIB. The total score was used to assess the possibilities of salvage and the outcome was measured by dividing the injuries into four groups according to their scores as follows: group I scored less than 5, group II 6 to 10, group III 11 to 15 and group IV 16 or more. A score of 14 to indicate amputation had the highest sensitivity and specificity. Our trauma score compared favourably with the Mangled Extremity Severity score in sensitivity (98% and 99%), specificity (100% and 17%), positive predictive value (100% and 97.5%) and negative predictive value (70% and 50%), respectively. A receiver-operating characteristic curve constructed for 67 type-IIIB injuries to assess the efficiency of the scores to predict salvage, showed that the area under the curve for this score was better (0.988 (± 0.013 . sem. )) than the Mangled Extremity Severity score (0.938 (± 0.039 . sem. )). All limbs in group IV and one in group III underwent amputation. Of the salvaged limbs, there was a significant difference in the three groups for the requirement of a flap for wound cover, the time to union, the number of surgical procedures required, the total days as an in-patient and the incidence of deep infection (p < 0.001 for all). The individual scores for covering and functional tissues were also found to offer specific guidelines in the management of these complex injuries. The scoring system was found to be simple in application and reliable in prognosis for both limb-salvage and outcome measures in type-IIIA and type-IIIB open injuries of the tibia

Due to increased life expectancy of human population, the amount of total knee replacements (TKR) is expected to increase. TKR reached a high grade of quality and safety, but most often it fail because of aseptic implant loosening caused by polyethylene (PE) wear debris. Wear is generated at the articulating surfaces, e.g. caused by three body particles, like bone fragments or bone cement particles. The aim of this experimental study was to compare the wear of tibial PE inserts combined with metallic and ceramic femoral components at three body wear situation induced by polymethylmethacrylate (PMMA) and zirconia (ZrO2) particles from the bone cement. Wear testing was performed for 5 Mio load cycles, using tibial standard PE inserts combined with the same CR femoral component, in two different materials, Cobalt Chromium (CoCrMo) and Biolox delta ® ceramic (Multigen Plus Knee System, Lima Corporate, Italy). A knee wear simulator, according to ISO 14243 (EndoLab GmbH, Rosenheim, Germany), was used to carry out the tests. The tests were performed in temperature-controlled test chambers at 37 °C, containing calf serum with a protein content of 30 g/l. Polymethylmethacrylate (PMMA) and zirconia (ZrO2) bone cement particles (Palacos R ®) were manufactured to a size of 30 μm. The three body particles were added at all stations onto the articulating surface of the tibial PE insert (7mg per condyle) at every 500,000 cycles. Wear was determined gravimetrically and the surfaces of tibial inserts were analysed by scanning electron microscope (SEM) after finishing the 5 million cycles. Furthermore, roughness of the PE insert surfaces and the articulating surfaces of the different femoral components were detected and the PE wear particles were analysed by SEM. The average gravimetrical wear rates of the tibial PE inserts in combination with CoCr and Biolox delta ® ceramic femoral components amounted to 6.4 ± 0.9 mg and 2.6 ± 0.4 mg per million cycles, respectively. Beside bone cement particles on the articulating surface of the PE inserts, polished surfaces and scratches were detected by SEM. In comparison to the untreated surfaces of the PE inserts at both material pairings the surface roughness at the articulating areas showed deep scratches and polished regions. Analyses of the metallic femoral components showed scratches at the articulating surfaces, none on ceramics. The present study pointed out the effect of femoral component material in an abrasive three body wear situation on the wear properties of TKR. The wear simulator tests showed that wear of PE inserts under three body wear conditions, in combination with ceramic femoral components, was significantly lower than with metallic femoral components. With regard to anti-allergic properties, ceramic femoral components are promising products for TKR

A 7-day randomised controlled pre-clinical trial utilising an existing extremity war wound model compared the efficacy of saline soaked gauze to commercially available dressings. The Flexor Carpi Ulnaris of anaesthetised rabbits was exposed to high-energy trauma using a computer-controlled jig and inoculated with 10. 6. Staphylococcus aureus 3 hours prior to application of dressing. Quantitative microbiological assessment demonstrated reduced bacterial counts in INADINE (Iodine) and ACTICOAT (Nanocrystalline Silver) groups and an increase in ACTIVON TULLE (Manuka Honey) group (2-way ANOVA p<0.05). Clinical observations were made throughout the study. Haematology and plasma cytokines were analysed at intervals. Post-mortem histopathology included subjective semi-quantitative assessment of pathology severity using light microscopy to grade muscle injury and lymph node activation. Tissue samples were also examined using scanning electron microscopy (SEM). There were no bacteraemias, abscesses, purulent discharge or evidence of contralateral axillary lymph node activation. There were no significant differences in animal behaviour, weight change, maximum body temperature or white blood cell count elevation nor in pathology severity in muscle or lymph nodes (Kruskal-Wallis). There was no evidence of bacterial penetration or biofilm formation on SEM. Interleukin-4 and Tumour Necrosis Factor α levels were significantly higher in the ACTIVON TULLE group (1-way ANOVA p<0.05). This time-limited study demonstrated a statistically significant reduction in Staphylococcus aureus counts in wounds dressed with INADINE and ACTICOAT and an increase in wounds dressed with ACTIVON TULLE. There was no evidence that any of these dressings cause harm but nor have we established any definite clinical advantage associated with the use of the dressings tested in this study

Staphylococcus aureus is a highly virulent pathogen and is implicated in approximately 50% of cases of septic arthritis. Studies investigating other S. aureus-related infections have suggested that alpha (Hla), beta (Hlb) and gamma (Hlg) toxins are key virulence factors. In particular, the ‘pore-forming’ alpha toxin is believed to be most potent. In this study, we have assessed the influence of alpha toxin on in situ chondrocyte viability. Osteochondral explants were harvested from the metacarpophalangeal joints of 3-year-old cows and placed into flasks containing Dulbecco's Modified Eagle's Medium. The flasks were then inoculated with the following isogenic ‘knockout’ strains of S. aureus: DU5946 (Hla+Hlb-Hlg-) or DU1090 (Hla-Hlb+Hlg+). The explants were incubated (37°C) and stained after 18, 24 and 40hrs with chloromethylfluorescein di-acetate and propidium iodide, labelling living chondrocytes green and dead cells red, respectively. Axial sections were imaged by confocal microscopy and the percentage cell death obtained using Volocity 4 software. The alpha toxin-producing S. aureus caused rapid cell death, with 24.8+/−3.7% at 18hrs and 44.6+/−7.2% at 24hrs. At 40hrs, there was significantly more chondrocyte death (87.4+/−3.6%; p<0.001) compared to the alpha toxin knockout strain (4.1+/−1.7%; means +/− SEM; n=4). In situ chondrocyte viability was significantly compromised by alpha toxin, with beta and gamma toxins having minimal effect. Further work will clarify the exact mechanism through which this important toxin induces chondrocyte death. Thereafter, it is hoped that targeted treatments can be developed to reduce the extent of cartilage destruction during, and after, an episode of septic arthritis

Engineered bone tissue to recreate the continuity of damaged skeletal segments is one of the field of interest of tissue engineering. Trabecular titanium has very good mechanical properties and high in vitro and in vivo biocompatibility: it can be used in biomedical applications to promote osteointegration demonstrating that it can be successfully used for regenerative medicine in orthopaedic surgery (1). Purpose of this investigation was to evaluate the behavior of adipose tissue derived stem cells (hASCs) cultured on scaffolds of Trabecular TitaniumTM (Lima-Lto) (TT). hASCs are considered to be multipotent mesenchymal stem cells that are easily induced to differentiate into functional osteoblasts both in vitro and in vivo (2). The hASCs were obtained from the subcutaneous adipose tissue of healthy donors during total hip replacement procedures after digestion with collagenase. They were seeded on monolayer and on the TT scaffolds, and incubated at 37 degrees C in 5% CO2 with osteogenic medium or control medium. The expression of bone-related genes using RT-PCR, time course of alkaline phosphatase activity and morphological investigation with Scanning Electron Microscopy (SEM) were performed to evaluate the osteogenic differentiation of hASCs. Alkaline phosphatase activity, marker of the differentiation toward the osteogenic pattern, was significantly higher in hASCs grown with osteogenic medium than in cells grown with control medium, both in monolayer and TT scaffolds; moreover, also alkaline phosphatase of hASCs grown on TT scaffolds in the presence of control medium increased with time, differently from that of cells grown on monolayer. The osteogenic differentiated hASCs expressed the bone-related genes type I collagen, osteocalcin, Runx-2 and alkaline phosphatase. SEM observations showed that hASCs differentiated toward osteoblast-like cells: they produced a big amount of extracellular matrix that covered the surface of the porous scaffolds with bridges between the pore walls. These data suggest that hASCs are able to adhere to TT scaffolds, to acquire an osteoblastic phenotype and to produce abundant extracellular matrix, with but also without osteogenic medium. We can therefore conclude that this material carries osteinductive properties being responsible of ostegenic differentiation; consequently, this scaffold/cells construct is effective to regenerate damaged tissue and to restore the function of bone tissue

Background. Wear particles are considered to be the major culprit for the aseptic loosening. Their characterization is thus crucial for the understanding of their bioreactivity and contribution to the development of aseptic loosening. Methods. Metal wear debris particles were analyzed directly in periprosthetic tissue resins by scanning electron microscopy (SEM) combined with back-scattered electron imaging (BSE) and energy dispersive X-ray spectroscopy (EDS). Four groups of tissue samples retrieved at revision operations of loosened hip implants with different bearing surfaces (metal-on-metal, ceramic-on-polyethylene and metal-on-polyethylene), and different material of the femoral stem (Ti alloy, CoCrMo and polymer combined with stainless steel) were investigated. Tissue samples were first analyzed histologicaly. Sections from the same paraffin blocks were then carbon coated and analyzed using SEM/BSE/EDS method. Results. Metal particles were detected in all samples. Their composition corresponded to the composition of the implant components. The gradation of metal particles ranged from +1 to +3. A considerable number of big metal particles were actually agglomerates of submicron particles visible only at higher magnification. The clustering of particles was observed primarily for CoCrMo and, to a lesser extent, for stainless steels particles. The median sizes of CoCrMo clusters in two groups of samples were 2.9 1.8 m (range, 0.5 to 7.6 m) and 3.2 1.0 m (range, 1.9 to 5.4 m). The effect of clustering was not observed for Ti particles. The median sizes of individual Ti particles determined in two groups of samples were 2.5 3.6 m (range, 0.4 to 17.3 m) and 4.3 2.8 m (range, 0.8 to 11.0 m). Conclusion. Scanning electron microscopy combined with back-scattered electron imaging is an appropriate and selective method to recognize metal particles in tissue sections, without being destructive to specimens. When the size of the particles is considered, however, it should be differed between the size of individual particles and size of clusters of particles. Besides its benefits, this study has some limitations: the detection of particles smaller than 0.4 m is difficult, and this method cannot be used to identify polyethylene particles

The osteointegration of a new three-dimensional reticular titanium material, Trabecular Titanium™, was assessed using a bilateral cancellous (distal femur, proximal tibia) and cortical (tibia diaphysis) bone drill hole model in 18 sheep. TT is a novel Ti6Al4V material characterized by a high open porosity and composed of multi-planar regular hexagonal cells. Two 5.0 mm diameter, 12 mm long cylinders (TT1 & TT2) of two different porosities (TT1:650 μm, TT2:1250 μm) were tested and compared to two solid predicate 5.0 mm diameter, 12 mm long Ti cylinders (PT1 & PT2) coated with porous Ti (PT1: vacuum-plasma spray coating; PT2: inert-gas shielding arc spray coating). Each implant type was surgically implanted at 4 separate locations in each sheep (16 implants per sheep). Three timepoints of 4, 16 and 52 weeks (n=6 sheep per timepoint) were used. Bone-implant interface was analyzed ex vivo by the determination of: 1) the shear strength (SS) measured during a push out test, 2) the percentage of bone in-growth (%B) using histomorphometry, 3) the bone apposition rate using fluorochrome labelling analysis and 4) the bone-implant contact using backscattered scanning electron microscopy (SEM). An ANOVA with a Bonferroni Post hoc test were used to detect differences between tested and predicate implants. P values 0.05 were considered significant. At 4 weeks, 5 out of the 6 TT1 could be pushed out of the cortical bone (COB) samples. The remaining TT1 collapsed during testing. All TT1 could be pushed of the cancellous bone (CAB) samples. Four out of the 6 TT2 could be pushed out of CAB and of the COB samples. At 16 and 52 weeks, only one TT1 and one TT2 could be pushed out of the bone samples, the remaining implants collapsed during testing. All the PTs were successfully pushed out at all timepoints. The mean %B of PT1 and PT2 did not significantly increase over time. For both materials, the mean %B ranged between 1.7% and 4.4% at 4 weeks and between 5.7% and 6.5% at 52 weeks. The mean %B of TT1 significantly increased over time in both COB (10.2% at 4 weeks, 46.2% at 16 weeks, 50.5% at 52 weeks) and CAB (5.8%, 23.9%, 24.3%). Similarly, the mean %B of TT2 significantly increased over time in both COB (7.8%, 48.6%, 65%) and CAB (4.5%, 24.1%, 38.6%). Bone apposition rates for the TT implants remained superior to 2 μm/day for the entire duration of the study. SEM showed an intimate bone-implant contact for all implant types at all timepoints. At 16 and 52 weeks, histomorphometry revealed an extensive osteointegration of the TT specimens. Bone-implant interface strength was so high for the TT implants that they could not be pushed out of the bone samples. The results of this study would indicate that the TT implants provide a good scaffold for bone in-growth

Osteolysis induced by UHMWPE debris has historically been one of the major causes of long term failure of TJR. An increase in concentration of polyethylene particles in the peri-prostheic tissue has been linked to an increased incidence of osteolysis. The dual mobility hip bearing concept mates a femoral head into a polyethylene liner which has an unconstrained articulation into a metal shell. The wear mechanism of the dual mobility hip bearing is distinct from a constrained single articulation design, which may result in a difference in wear debris particles. The aim of this study is to evaluate wear debris generated from a dual mobility hip and compare it to a conventional single articulation design when both are manufactured from sequentially crosslinked and annealed polyethylene. The dual mobility hip (Restoration ADM) incorporated a 28mm CoCr femoral head into a polyethylene liner that articulates against a metal shell (48mm ID). The conventional hip (Trident®) mated a 28mm CoCr femoral head against a polyethylene liner. The polyethylene for all liners was sequentially crosslinked and annealed (X3). A hip joint simulator was used for testing at a rate of 1 Hz with cyclic Paul curve physiologic loading. A serum sample from each testing group was collected. Serum samples were protein digested following the published process by Scott et al. The digested serum was then filtered through a series of polycarbonate filter papers of decreasing size and sputter coated with gold for analysis using SEM. Image fields were randomized and wear debris was compared in terms of its length, width, aspect ration, and equivalent circular diameter (ECD). A total of 149 conventional hip particles and 114 dual mobility hip particles were imaged. Results show a majority of particles are of spherical nature and images do not indicate the presence of fibrillar or larger elongated polyethylene debris. Particle length between designs is not statistically different, while all other comparisons show statistical significance (p<0.05). It is hypothesized that the dual mobility hip system reduces the total amount of cross-shear motion on any one articulation, which aids in the reduction in wear. This design feature may be responsible for the slight difference in morphology of dual mobility wear debris when compared to the constrained hip design. The length of the particles was similar, simply indicating a different shape rather than a marked reduction in overall size. The debris generated is this study was from highly crosslinked polyethylene in two different designs, which produced a very significant decrease in quantity of particles when compared to the quantity of debris from conventional polyethylene. The wear debris was of similar length in both designs and so we do not expect any difference in biological response to debris from either device. The dual mobility design has also shown no effect of cup abduction angle on wear demonstrating forgiveness to implant positioning. This advantage, combined with the low wear rate and similar length wear particles, should lead to good clinical performance of dual mobility cups with sequentially irradiated and annealed polyethylene

Aims

Outcome measures quantifying aspects of health in a precise, efficient, and user-friendly manner are in demand. Computer adaptive tests (CATs) may overcome the limitations of established fixed scales and be more adept at measuring outcomes in trauma. The primary objective of this review was to gain a comprehensive understanding of the psychometric properties of CATs compared with fixed-length scales in the assessment of outcome in patients who have suffered trauma of the upper limb. Study designs, outcome measures and methodological quality are defined, along with trends in investigation.

Objectives

The purpose of this study was to refine an accepted contaminated rat femur defect model to result in an infection rate of approximately 50%. This threshold will allow examination of treatments aimed at reducing infection in open fractures with less risk of type II error.

Aims

The Intraosseous Transcutaneous Amputation Prosthesis (ITAP) may improve quality of life for amputees by avoiding soft-tissue complications associated with socket prostheses and by improving sensory feedback and function. It relies on the formation of a seal between the soft tissues and the implant and currently has a flange with drilled holes to promote dermal attachment. Despite this, infection remains a significant risk. This study explored alternative strategies to enhance soft-tissue integration.

We evaluated the effect of low-intensity pulsed ultrasound stimulation (LIPUS) on the remodelling of callus in a rabbit gap-healing model by bone morphometric analyses using three-dimensional quantitative micro-CT. A tibial osteotomy with a 2 mm gap was immobilised by rigid external fixation and LIPUS was applied using active translucent devices. A control group had sham inactive transducers applied. A region of interest of micro-CT was set at the centre of the osteotomy gap with a width of 1 mm. The morphometric parameters used for evaluation were the volume of mineralised callus (BV) and the volumetric bone mineral density of mineralised tissue (mBMD). The whole region of interest was measured and subdivided into three zones as follows: the periosteal callus zone (external), the medullary callus zone (endosteal) and the cortical gap zone (intercortical). The BV and mBMD were measured for each zone.

In the endosteal area, there was a significant increase in the density of newly formed callus which was subsequently diminished by bone resorption that overwhelmed bone formation in this area as the intramedullary canal was restored. In the intercortical area, LIPUS was considered to enhance bone formation throughout the period of observation. These findings indicate that LIPUS could shorten the time required for remodelling and enhance the mineralisation of callus.

Aims

The PROximal Fracture of the Humerus Evaluation by Randomisation (PROFHER) randomised clinical trial compared the operative and non-operative treatment of adults with a displaced fracture of the proximal humerus involving the surgical neck. The aim of this study was to determine the long-term treatment effects beyond the two-year follow-up.

Systemic antibiotics reduce infection in open fractures. Local delivery of antibiotics can provide higher doses to wounds without toxic systemic effects. This study investigated the effect on infection of combining systemic with local antibiotics via polymethylmethacrylate (PMMA) beads or gel delivery.

An established Staphylococcus aureus contaminated fracture model in rats was used. Wounds were debrided and irrigated six hours after contamination and animals assigned to one of three groups, all of which received systemic antibiotics. One group had local delivery via antibiotic gel, another PMMA beads and the control group received no local antibiotics. After two weeks, bacterial levels were quantified.

Combined local and systemic antibiotics were superior to systemic antibiotics alone at reducing the quantity of bacteria recoverable from each group (p = 0.002 for gel; p = 0.032 for beads). There was no difference in the bacterial counts between bead and gel delivery (p = 0.62).

These results suggest that local antibiotics augment the antimicrobial effect of systemic antibiotics. Although no significant difference was found between vehicles, gel delivery offers technical advantages with its biodegradable nature, ability to conform to wound shape and to deliver increased doses. Further study is required to see if the gel delivery system has a clinical role.

Cite this article: Bone Joint J 2015;97-B:1423–7.

Our aim was to assess the reproducibility and the reliability of the Weber classification system for fractures of the ankle based on anteroposterior and lateral radiographs. Five observers with varying clinical experience reviewed 50 sets of blinded radiographs. The same observers reviewed the same radiographs again after an interval of four weeks. Inter- and intra-observer agreement was assessed based on the proportion of agreement and the values of the kappa coefficient.

For inter-observer agreement, the mean kappa value was 0.61 (0.59 to 0.63) and the proportion of agreement was 78% (76% to 79%) and for intra-observer agreement the mean kappa value was 0.74 (0.39 to 0.86) with an 85% (60% to 93%) observed agreement. These results show that the Weber classification of fractures of the ankle based on two radiological views has substantial inter-observer reliability and intra-observer reproducibility.

Most animal studies indicate that early irrigation and debridement reduce infection after an open fracture. Unfortunately, these studies often do not involve antibiotics. Clinical studies indicate that the timing of initial debridement does not affect the rate of infection but these studies are observational and fraught with confounding variables. The purpose of this study was to control these variables using an animal model incorporating systemic antibiotics and surgical treatment.

We used a rat femur model with a defect which was contaminated with Staphylococcus aureus and treated with a three-day course of systemic cefazolin (5 mg/kg 12-hourly) and debridement and irrigation, both of which were initiated independently at two, six and 24 hour time points. After 14 days the bone and hardware were harvested for separate microbiological analysis.

No animal that received antibiotics and surgery two hours after injury had detectable bacteria. When antibiotics were started at two hours, a delay in surgical treatment from two to six hours significantly increased the development of infection (p = 0.047). However, delaying surgery to 24 hours increase the rate of infection, but not significantly (p = 0.054). The timing of antibiotics had a more significant effect on the proportion of positive samples than earlier surgery. Delaying antibiotics to six or 24 hours had a profoundly detrimental effect on the infection rate regardless of the timing of surgery. These findings are consistent with the concept that bacteria progress from a vulnerable planktonic form to a treatment-resistant biofilm.

We have carried out a retrospective review of 20 patients with segmental fractures of the tibia who had been treated by circular external fixation. We describe the heterogeneity of these fractures, their association with multiple injuries and the need for multilevel stability with the least compromise of the biology of the fracture segments. The assessment of outcome included union, complications, the measurement of the functional IOWA knee and ankle scores and the general health status (Short-form 36).

The mean time to union was 21.7 weeks (12.8 to 31), with no difference being observed between proximal and distal levels of fracture. Complications were encountered in four patients. Two had nonunion at the distal level, one a wire-related infection which required further surgery and another shortening of 15 mm with 8° of valgus which was clinically insignificant. The functional scores for the knee and ankle were good to excellent, but the physical component score of the short-form 36 was lower than the population norm. This may be explained by the presence of multiple injuries affecting the overall score.