Sclerostin does not play a major role in the pathogenesis of skeletal complications in type 2 diabetes mellitus.

In contrast to previously reported elevations in serum sclerostin levels in diabetic patients, the present study shows that the impaired bone microarchitecture and cellular turnover associated with type 2 diabetes mellitus (T2DM)-like conditions in ZDF rats are not correlated with changes in serum and bone sclerostin expression. INTRODUCTION: T2DM is associated with impaired skeletal structure and a higher prevalence of bone fractures. Sclerostin, a negative regulator of bone formation, is elevated in serum of diabetic patients. We aimed to relate changes in bone architecture and cellular activities to sclerostin production in the Zucker diabetic fatty (ZDF) rat. METHODS: Bone density and architecture were measured by micro-CT and bone remodelling by histomorphometry in tibiae and femurs of 14-week-old male ZDF rats and lean Zucker controls (n = 6/group). RESULTS: ZDF rats showed lower trabecular bone mineral density and bone mass compared to controls, due to decreases in bone volume and thickness, along with impaired bone connectivity and cortical bone geometry. Bone remodelling was impaired in diabetic rats, demonstrated by decreased bone formation rate and increased percentage of tartrate-resistant acid phosphatase-positive osteoclastic surfaces. Serum sclerostin levels (ELISA) were higher in ZDF compared to lean rats at 9 weeks (+40 %, p < 0.01), but this difference disappeared as their glucose control deteriorated and by week 14, ZDF rats had lower sclerostin levels than control rats (-44 %, p < 0.0001). Bone sclerostin mRNA (qPCR) and protein (immunohistochemistry) were similar in ZDF, and lean rats at 14 weeks and genotype did not affect the number of empty osteocytic lacunae in cortical and trabecular bone. CONCLUSION: T2DM results in impaired skeletal architecture through altered remodelling pathways, but despite altered serum levels, it does not appear that sclerostin contributes to the deleterious effect of T2DM in rat bone.

The burden of bone, native joint and soft tissue infections on orthopaedic emergency referrals in a city hospital.

Introduction Bone, native joint and soft tissue infections are frequently referred to orthopaedic units although their volume as a proportion of the total emergency workload has not been reported previously. Geographic and socioeconomic variation may influence their presentation. The aim of this study was to quantify the burden of such infections on the orthopaedic department in an inner city hospital, determine patient demographics and associated risk factors, and review our current utilisation of specialist services. Methods All cases involving bone, native joint and soft tissue infections admitted under or referred to the orthopaedic team throughout 2012 were reviewed retrospectively. Prosthetic joint infections were excluded. Results Almost 15% of emergency admissions and referrals were associated with bone, native joint or soft tissue infection or suspected infection. The cohort consisted of 169 patients with a mean age of 43 years (range: 1-91 years). The most common diagnosis was cellulitis/other soft tissue infection and the mean length of stay was 13 days. Two-thirds of patients (n=112, 66%) underwent an operation. Fifteen per cent of patients were carrying at least one blood borne virus, eleven per cent were alcohol dependent, fifteen per cent were using or had been using intravenous drugs and nine per cent were homeless or vulnerably housed. Conclusions This study has shown that a significant number of patients are admitted for orthopaedic care as a result of infection. These patients are relatively young, with multiple complex medical and social co-morbidities, and a long length of stay.

Presence and characterisation of anaemia in diabetic foot ulceration.

Introduction. Diabetic foot ulceration (DFU) is the commonest cause of severe limb ischaemia in the western world. In diabetes mellitus, anaemia is frequently unrecognized, yet studies have shown that it is twice as common in diabetics compared with nondiabetics. We aimed to assess the incidence of anaemia and further classify the iron deficiency seen in a high-risk DFU patient group. Methods. An observational study was undertaken in a multidisciplinary diabetic foot clinic setting. All patients with DFU attending over a four-month period were included. Anaemia was defined as haemoglobin (Hb) levels <12 g/dL. Iron deficiency was classified according to definitions of AID (absolute iron deficiency) and FID (functional iron deficiency). Results. 27 patients had DFU; 14 (51.9%) were anaemic; two (7.41%) had severe anaemia (Hb < 10 g/dL). No patient had B12 or Folate deficiency. In patients with anaemia, there was significant spread of indices. Only one patient had "textbook" absolute iron deficiency (AID) defined as low Hb, MCV, MCH, and ferritin. Functional iron deficiency (FID) was seen in a further seven patients (25.5%). Conclusion. Anaemia and iron deficiency are a common problem in patients with DFU. With current clinical markers, it is incredibly difficult to determine causal relationships and further in-depth scientific study is required.

Failure in the application of fragility fracture prevention guidelines.

INTRODUCTION: The cost of fragility fractures to the UK economy is predicted to reach £2.2 billion by 2025. We studied our hip fracture population to establish whether national guidelines on fragility fracture prevention were being followed, and whether high risk patients were identified and treated by local care services. METHODS: Data on a consecutive series of trauma hip fracture admissions were collected prospectively over 14 months. National Institute for Health and Care Excellence (NICE) and National Osteoporosis Guideline Group (NOGG) recommendations and FRAX(®) risk calculations were applied to patients prior to their admission with a new hip fracture. RESULTS: Overall, 94 patients were assessed against national guidelines. The mean population age was 77 years. Almost a quarter (22%) of patients had suffered a previous fragility fracture. The mean FRAX(®) ten-year probability of hip fracture was 7%. According to guidelines, 45% of the study population required treatment, 35% fulfilled criteria for investigation and reassessment, and 20% needed no further management. In practice, 27% received treatment, 4% had undergone dual energy x-ray absorptiometry and were untreated, and 69% had not been investigated and were untreated. In patients meeting intervention thresholds, only 33% of those who required treatment were receiving treatment in practice. CONCLUSIONS: In conjunction with NICE and NOGG recommendations, FRAX(®) was able to identify 80% of our fracture population as intermediate or high risk on the day of fracture. Correct management was evident in a third of cases with a pattern of inferior guideline compliance seen in a London population. There remains a lack of clarity over the duty of care in fragility fracture prevention.

Disposable NPWT device to facilitate early patient discharge following complex DFU.

Negative pressure wound therapy (NPWT) is a valuable tool in complex wound management. Despite its popularity, NPWT therapy systems can have drawbacks, including reduced mobility and cost; therefore, NPWT is predominantly hospital based. The advent of a new, lightweight and disposable system may aid early discharge and permit outpatient treatment. This case report describes how one such system facilitated early discharge in a patient with a complex diabetic foot ulcer.

The reliability and variation of measurements of the os calcis angles in children.

The databases of the Picture Archiving and Communication Systems of two hospitals were searched and all children who had a lateral radiograph of the ankle during their attendance at the emergency department were identified. In 227 radiographs, Bohler's and Gissane's angles were measured on two separate occasions and by two separate authors to allow calculation of inter- and intra-observer variation. Intraclass correlation coefficients were used to assess the reliability of the measurements. For Bohler's angle the overall inter-observer reliability, the intraclass correlation coefficient was 0.90 and the intra-observer reliability 0.95, giving excellent agreement. This reliability was maintained across the age groups. For Gissane's angle, inter- and intra-observer reliability was only fair or poor across most age groups. 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. The age-related radiologic changes presented here may help in the interpretation of injuries to the hindfoot in children.

Tendon re-attachment to metal prostheses in an in vivo animal model using demineralised bone matrix.

We used demineralised bone matrix (DBM) to augment re-attachment of tendon to a metal prosthesis in an in vivo ovine model of reconstruction of the extensor mechanism at the knee. We hypothesised that augmentation of the tendon-implant interface with DBM would enhance the functional and histological outcomes as compared with previously reported control reconstructions without DBM. Function was assessed at six and 12 weeks postoperatively, and histological examination was undertaken at 12 weeks. A significant increase of 23.5% was observed in functional weight-bearing at six weeks in the DBM-augmented group compared with non-augmented controls (p = 0.004). By 12 weeks augmentation with DBM resulted in regeneration of a more direct-type enthesis, with regions of fibrocartilage, mineralised fibrocartilage and bone. In the controls the interface was predominantly indirect, with the tendon attached to the bone graft-hydroxyapatite base plate by perforating collagen fibres.

A comparison of augmentation techniques for reconstruction of the extensor mechanism following proximal tibial replacement in an experimental animal model.

We used an in vivo model to assess the use of an autogenous cancellous bone block and marrow graft for augmenting tendon reattachment to metallic implants. We hypothesised that augmentation of the tendon-implant interface with a bone block would enable retention of the graft on the implant surface, enhance biological integration, and result in more consistent functional outcomes compared with previously reported morcellised graft augmentation techniques. A significant improvement in functional weight-bearing was observed between six and 12 weeks. The significant increase in ground reaction force through the operated limb between six and 12 weeks was greater than that reported previously with morcellised graft augmented reconstructions. Histological appearance and collagen fibre orientation with bone block augmentation more closely resembled that of an intact enthesis compared with the morcellised grafting technique. Bone block augmentation of tendon-implant interfaces results in more reliable functional and histological outcomes, with a return to pre-operative levels of weight-bearing by 24 weeks.

The novel use of resorbable Vicryl mesh for in vivo tendon reconstruction to a metal prosthesis.

We examined the mechanical properties of Vicryl (polyglactin 910) mesh in vitro and assessed its use in vivo as a novel biomaterial to attach tendon to a hydroxyapatite-coated metal implant, the interface of which was augmented with autogenous bone and marrow graft. This was compared with tendon re-attachment using a compressive clamp device in an identical animal model. Two- and four-ply sleeves of Vicryl mesh tested to failure under tension reached 5.13% and 28.35% of the normal ovine patellar tendon, respectively. Four-ply sleeves supported gait in an ovine model with 67.05% weight-bearing through the operated limb at 12 weeks, without evidence of mechanical failure. Mesh fibres were visible at six weeks but had been completely resorbed by 12 weeks, with no evidence of chronic inflammation. The tendon-implant neoenthesis was predominantly an indirect type, with tendon attached to the bone-hydroxyapatite surface by perforating collagen fibres.

Ionising radiation exposure to orthopaedic trainees: the effect of sub-specialty training.

INTRODUCTION: We monitored image intensifier use by orthopaedic trainees to assess their exposure to ionising radiation and to investigate the influence of sub-specialty training. MATERIALS AND METHODS: Five different orthopaedic registrars recorded their monthly image intensifier screening times and exposure doses for all cases (trauma and elective), for a combined total of 12 non-consecutive months. Radiation exposure was monitored using shoulder and waist film badges worn both by surgeons and radiographers screening their cases. RESULTS: Registrars in spinal sub-specialties were exposed to significantly higher doses per case and cumulative doses per month than non-spinal trainees (P < 0.05), but significantly lower screening times per case (P < 0.05). There were no significant differences in cumulative screening times per month (P > 0.05). Regression analysis for all surgeons showed a significant relationship between shoulder film badge reading and cumulative dose exposed per month (P < 0.05), but not for cumulative screening time. Shoulder film badge recordings were significantly higher for spinal compared with non-spinal registrars (P < 0.05), although all badges were below the level for radiation reporting. Only one radiographer badge recorded a dose above threshold. CONCLUSIONS: Whilst the long-term effects of sub-reporting doses of radiation are not fully understood, we consider that this study demonstrates that trainees should not be complacent in accepting inadequate radiation protection. The higher doses encountered with spinal imaging means that sub-specialty trainees should be alerted to the risk of their increased exposure. The principle of minimising radiation exposure must be maintained by all trainees at all times.

Assessment of reproducibility and accuracy in templating hybrid total hip arthroplasty using digital radiographs.

In 20 patients undergoing hybrid total hip arthroplasty, the reproducibility and accuracy of templating using digital radiographs were assessed. Digital images were manipulated using either a ten-pence coin as a marker to scale for magnification, or two digital-line methods using computer software. On-screen images were templated with standard acetate templates and compared with templating performed on hard-copy digital prints. The digital-line methods were the least reliable and accuracy of sizing compared with the inserted prostheses varied between -1.6% and +10.2%. The hard-copy radiographs showed better reproducibility than the ten-pence coin method, but were less accurate with 3.7% undersizing. The ten-pence coin method was the most accurate, with no significant differences for offset or acetabulum, and undersizing of only 0.9%. On-screen templating of digital radiographs with standard acetate templates is accurate and reproducible if a radiopaque marker such as a ten-pence coin is included when the original radiograph is taken.

Extensor mechanism reconstruction after proximal tibial replacement.

We developed an in vivo model of the attachment of a patellar tendon to a metal implant to simulate the reconstruction of an extensor mechanism after replacement of the proximal tibia. In 24 ewes, the patellar tendon was attached to a hydroxyapatite (HA)-coated titanium prosthesis. In 12, the interface was augmented with autograft containing cancellous bone and marrow. In the remaining ewes, the interface was not grafted. Kinematic gait analysis showed nearly normal function of the joint by 12 weeks. Force-plate assessment showed a significant increase in functional weight-bearing in the grafted animals (p = 0.043). The tendon-implant interface showed that without graft, encapsulation of fibrous tissue occurred. With autograft, a developing tendon-bone-HA-implant interface was observed at six weeks and by 12 weeks a layered tendon-fibrocartilage-bone interface was seen which was similar to a direct-type enthesis. With stable mechanical fixation, an appropriate bioactive surface and biological augmentation the development of a functional tendon-implant interface can be achieved.

A histomorphological study of tendon reconstruction to a hydroxyapatite-coated implant: regeneration of a neo-enthesis in vivo.

The attachment of tendons and ligaments to massive endoprostheses remains a clinical challenge due to the difficulty in achieving a soft tissue implant interface with a mechanical strength sufficient to transmit the forces necessary for locomotion. We have used an in vivo animal model to study patellar tendon attachment to an implant surface. The interface generated when the patellar tendon was attached to a hydroxyapatite (HA) coated implant was examined using light microscopy and a quantitative histomorphological analysis was performed. In the Autograft Group, the interface was augmented with autogenous cancellous bone and marrow graft, and at six weeks an indirect-like insertion was observed. At twelve weeks, the interface was observed to be a layered neo-enthesis, whose morphology was similar to a normal direct tendon insertion. In the HA Group, the tendon-implant interface was not augmented, and the implant was enveloped by a dense collagenous fibrous tissue. This study shows that a tendon-implant neo-enthesis can develop in situ by employing a suitable implant surface in association with biological augmentation.