The increased incidence of type 2 Diabetes Mellitus is associated with an impaired skeletal structure and a higher prevalence of bone fractures. Sclerostin is a negative regulator of bone formation produced by osteocytes and there is recent evidence that its expression in serum is elevated in diabetic patients compared to control subjects. In this study, we test whether hyperglycemia affects serum and bone sclerostin levels in a rat model of type 2 Diabetes as well as sclerostin production by osteoblasts in culture.

We used Zucker diabetic fatty (ZDF) male rats (n=6) that spontaneously develop obesity and frank diabetes around 8–9 weeks of age and Zucker lean rats as controls (n=6) to examine sclerostin expression in serum at 9, 11 and 13 weeks using a specific ELISA. Sclerostin expression in bone tibiae was examined at 12 weeks using immunocytochemistry. Rat osteoblast-like cells UMR-106 were cultured in the presence of increasing concentrations of glucose (5, 11, 22 and 44 mM) during 48 hours and sclerostin mRNA expression and release in the supernatant determined by quantitative PCR and ELISA, respectively.

Our results show that serum sclerostin levels are higher in the diabetic rats compared to lean rats at 9 weeks (+ 140%, p<0.01). Our preliminary results using immunocytochemistry for sclerostin did not show any major difference in sclerostin expression in tibiae of diabetic rats compared to lean ones, although we observed many osteocytic empty lacunae in cortical bone from diabetic rats. Glucose dose-dependent stimulated sclerostin mRNA and protein production in mature UMR106 cells while it had no effect on osteocalcin expression.

Altogether, our data suggest that sclerostin production by mature osteoblasts is increased by hyperglycemia in vitro and enhanced in serum of diabetic rats. Furthers studies are required to determine whether sclerostin could contribute to the deleterious effect of Diabetes on bone.

Introduction

Medial calcaneal displacement osteotomy with an FDL tendon transfer is a common method of correcting pes planus deformity secondary to grade II tibialis posterior dysfunction. There is currently no evidence that calcaneal displacement alters the centre of pressure in the foot from a medial to a more central position as the normal shape is reconstituted.

Medial Displacement Osteotomy (MDO) of the os calcis is used to correct the hind foot valgus in a flat foot deformity. Screw fixation is commonly used although contemporary locking plate systems are now available. This study tested the hypothesis that a 10mm MDO would support a higher load to failure with a locked step plate than with a single cannulated screw.

Background: A novel method for harvesting the flexor digitorum longus (FDL) tendon has previously been described via a plantar approach based on a surface coordinate. The aim of this investigation is to provide a comparison with the traditional medial midfoot dissection for tendon harvest.

Methods: The FDL tendon was exposed in 10 cadaveric feet via a limited plantar approach and also medially as far as could be accessed via the knot of Henry. The FDL was marked with a metal clip in each approach. The lengths of the skin incisions were recorded and the distance between the two markers was measured. The morphology of the FDL tendon was observed including interconnections with the flexor hallucis longus (FHL) tendon.

Results: The mean additional length of tendon accessed via the plantar approach was 22.9 mm with a mean reduction in skin incision length of 15.6 mm. The FDL tendon showed some division at the site of the plantar exposure and there were FDL - FHL interconnections in nine of the feet with three distinct patterns observed.

Conclusion: Using the plantar exposure, a longer length of tendon can be obtained through a smaller skin incision, which has been quantified here. Observations on FDL tendon morphology and interconnections may have clinical significance.

Introduction: The assessment of quality in the provision of healthcare is one of the core features of the National Health Service in the 21st Century. From April 2009 Patient Reported Outcome Measure (PROM) data are being collected for the Department of Health for elective hip and knee arthroplasty using generic and disease specific measures of health status. The perceived uses of these data may be for research, assessment of procedural outcome, measures of health inequalities and to aid commissioning groups in selecting their secondary care providers. Foot and ankle surgery covers a wide spectrum of operative procedures with patient responses less predictable than with major joint arthroplasty. We report the use of a sixteen point satisfaction-based questionnaire in order to investigate the nature of patient outcome after the processes of foot and ankle surgery.

Methods: A prospective series of 100 two-part Visual Analogue Scale (VAS) questionnaires was distributed to patients undergoing elective foot and ankle surgery at the Northern General Hospital under the care of four foot and ankle surgeons over a three-month period. The questionnaires were numbered to allow patient anonymity. The first part of nine questions enquired about pre-operative preparation and information and was distributed before surgery. The second part of seven questions, distributed at the first post-operative clinic sought to investigate their hospital and operative experience. Free text comments were requested in addition to the VAS responses, which were expressed as percentages.

Results: 97% of part one and 85% of part two questionnaires were returned completed. 82% had both parts completed and matched. The day case to inpatient ratio was 55: 45. For part one, all clinically related questions scored more than 90% satisfaction, with only two scores for administration-based questions falling below this level. For part two, satisfaction for clinical questions again scored more than 90% and overall, all scored more than 80% satisfaction. Only 23% of pre-operative and 28% of post-operative questionnaires were returned with free-text comments.

Conclusions: A simple patient satisfaction-based questionnaire may be as useful as existing non-validated generic scoring systems used in foot and ankle surgery when assessing quality in the health service, particularly where regional demographics or referral patterns may be important factors influencing patient outcomes. Active dialogue with the surgical colleges and Department of Health should be pursued to avoid inappropriate outcome measures being imposed in foot and ankle surgery.

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: Templating of radiographs is part of pre-operative planning in Total Hip Replacement (THR). Digital radiograph technology allows the manipulation of images, altering magnification and therefore affecting accuracy and reproducibility in templating. We have performed a study to investigate templating for hybrid total hip arthroplasty comparing digital hard copies with three computer methods to scale for magnification, in order to assess whether on-screen images can be templated directly with existing acetate templates.

Methods: 20 patients undergoing hybrid THR had pre-operative radiographs taken with a 10 pence coin attached to the skin overlying their greater trochanter. On-screen computer images were manipulated using either the 10p coin as a marker to scale for magnification, or two digital line methods using computer software against external ruler scales. Templating were performed for acetabular size, femoral offset, stem offset and stem size by three grades of observer, and the on-screen images were compared with hard copy digital prints. Intraclass Correlation (ICC) analyses were performed to assess intra-observer and inter-observer variability for the four methods. Comparisons were also made between templated results and the sizes of the inserted prostheses.

Results: All methods showed good reproducibility with all ICC values for intra-observer variability greater than 0.7. Inter-observer variability was less consistent, and the two digital line methods were the least reliable, with accuracy of sizing compared with the inserted prostheses varying between −1.6% to +10.2%. The hard copy radiographs showed better reproducibility than the 10p method, but less accuracy with 3.7% under-sizing. The 10p method was most accurate, with no significant differences for offset or acetabulum compared with the inserted prostheses, and templated under-sizing of only 0.9%.

Discussion: On-screen templating of digital radiographs with standard acetate templates is accurate and reproducible if a radio-opaque marker such as a 10p coin is included when taking the original radiograph.

Introduction: Functional outcome following proximal tibial replacement can be impaired by extensor mechanism inefficiency. Current methods used to re-attach the patellar tendon result in varied levels of extensor function. Successful attachment of the patellar tendon requires initial mechanical stability and long-term biological fixation. We have employed a prosthesis, to model patellar tendon re-attachment, to test the hypothesis that biological augmentation of an implant which can provide sufficient mechanical integrity will allow a tendon-implant interface to develop that is similar in function and morphology to a normal tendon-bone interface.

Methods: The right patellar tendon in 24 Skeletally mature Friesland ewes was transfixed between the interlocking spikes of a hydroxyapatite-coated, customized tendon clamp to simulate patellar tendon re-attachment to a proximal tibial replacement. In 12 animals (Autograft group) the clamp attachment was augmented with autologous cancellous bone and marrow graft harvested from the ipsilateral iliac crest at the time of surgery, whilst the remaining animals (HA group) served as un-supplemented controls. Functional outcome was assessed using force plate measurements and two-dimensional optical kinematic gait analysis. Animals were euthanised at 6 and 12 weeks. The specimens were harvested, processed for histology and examined using light microscopy.

Results: The clamp device provided sufficient mechanical fixation of the patellar tendon to allow immediate weight bearing. Gait analysis showed that the range of movement of the stifle (knee) joint was not compromised by the surgical intervention at 6 or 12 weeks post-operation. An extensor lag observed at 6 weeks in both the Autograft and HA group was seen to fully recover by 12 weeks post-operation. There was a significant increase in functional weight bearing through the operated limb of the Autograft group animals between 6 and 12 weeks, which was not observed in the HA group. The tendon-implant interface in the HA group animals showed a fibrous tissue encapsulation of the HA coated surface, with collagen fibrils running parallel to the implant surface. In the Autograft group at 6 weeks post-operation a soft tissue – bone – HA interface had developed, similar in morphology to that of an indirect-type enthesis. Perpendicular orientated Sharpey’s-like fibres were observed spanning the region between the tendon and the HA coated implant and the bone graft material was seen to be undergoing active remodelling. By 12 weeks post-operation the interface was layered with regions of fibrocartilage clearly visible, more closely resembling the morphology of a direct-type enthesis.

Discussion: The clamp device provided sufficient mechanical fixation of the patellar tendon to allow immediate use the operated limb. The incorporation of a bio-active implant coating and biological augmentation encouraged a neo-enthesis to develop with near normal functional properties, and morphology similar to that of a normal patellar tendon-bone direct-type enthesis.