Introduction

The management of open or unstable ankle and distal tibial fractures pose many challenges. In certain situations, hindfoot nailing (HFN) is indicated, however this depends on surgeon preference and regional variations exist. This study sought to establish the current management and outcomes of complex ankle fractures in the UK.

Introduction

Charcot neuroarthropathy (CN) of foot and ankle presents significant challenges to the orthopaedic foot and ankle surgeon. Current treatment focuses on conservative management during the acute CN phase with offloading followed by deformity correction during the chronic phase. However, the deformity can progress in some feet despite optimal offloading resulting ulceration, infection, and limb loss. Our aim was to assess outcomes of primary surgical management with early reconstruction.

Background

Corrective fusion of a deformed / unstable Charcot neuroarthropathy (CN)of the midfoot and hindfoot is performed with the aim to prevent ulcers and maintain patient mobility.

Aims

Impaired fracture repair in patients with type 2 diabetes mellitus (T2DM) is not fully understood. In this study, we aimed to characterize the local changes in gene expression (GE) associated with diabetic fracture. We used an unbiased approach to compare GE in the fracture callus of Zucker diabetic fatty (ZDF) rats relative to wild-type (WT) littermates at three weeks following femoral osteotomy.

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.

Lunate or perilunate dislocations are common carpal injuries. Current treatment of these injuries by repair or reconstruction of intra-carpal ligaments is largely based on Mayfield's description of sequential failure of these ligaments.

We do treat significant number of these injuries. We have observed that dorsal wrist capsule is attached to dorsal aspect of proximal carpal row and its interosseous ligaments by vertically oriented identifiable fibres. This can be seen as carpal bones suspended from dorsal capsule, akin to cloths suspended from a washing line. We have also observed that in lunate or perilunate dislocations, dorsal capsule is peeled off from the dorsal aspect of lunate and distal radius, similar to a Bankart lesion in the shoulder. We believe that dorsal capsule plays a bigger role in the stabilising mechanism of carpal bone than the intercarpal ligaments. It has not been described before.

We dissected three cadaveric wrists and found vertical fibres running from dorsal wrist capsule/ligaments to the dorsal components of the scapholunate and lunotriquetralinterosseous ligaments. We have modified the Mayo approach to dorsal wrist capsule and use suture anchors to attach dorsal capsule/ligaments to scaphoid, lunate and triquetrum rather than repairing intra-carpal ligament. We have used this technique in 26 patients so far. Follow up for more than 4 years have shown satisfactory results and no significant recurrence of instability.

We present a novel, so far unreported, method of repairing the intracarpal injuries, using the dorsal capsule/ligaments, based on anatomic and intra-operative observations.

We present a novel approach to the management of patients with longstanding heel ulcers complicated by open calcaneal fractures. The principles of management of diabetic foot ulcers were combined with applied physiology of fracture healing.

Case notes of 6 consecutive patients who presented to our diabetic foot clinic between January 2009 and December 2009 were reviewed. Type of diabetes, duration of heel ulcer, type of fracture and treatment given were recorded. Initial treatment consisted of regular local debridement and application of dressing. Vacuum Assisted Continuous (VAC) pump application was deferred until 6 weeks to preserve fracture hematoma and thereby initiate fracture healing. In all patients, VAC pump was started at 6 weeks and continued till healing of ulcer to adequate depth. Infection was treated aggressively with appropriate antibiotics according to the microbiology results.

The average age was 53 (40-60) and the mean duration of follow up was 6 months. All wound healed completely, fractures united and patients returned to previous function.

An open calcaneal fracture presents a severe injury likely to be complicated by infection and consequent osteomyelitis leading to amputations. In our group of patients, a novel treatment approach consisting of multidisciplinary model resulted in successful limb preservation and return to function.

Background: Conventional magnetic resonance pulse sequence echo times (TEs) produces no signal of cortical bone. In this pilot study we wished to explore the value of a novel pulse sequence with an ultrashort echo time (UTE), which is able to detect signal from cortical bone and periosteum (Ref.). The signal obtained using an UTE sequence from cortical bone reflects the soft tissue component of cortical bone including its vasculature. We hypothesized that conditions, which alter the soft tissue component and vascularity of bone, show a change in signal. We have examined the lower limb in patients and volunteers of different age and at different time points following fracture of the tibia.

Subjects and Methods: Seven volunteers (aged 29 – 85 years) and eight patients with acute fractures of the tibia (aged 18 – 56 years) were examined at different time points (2 days – 16 weeks) following fracture, in three of the patients serial scans were obtained. Three patients were examined years following bone injury: one patient with a hypertrophic mal-union at 5 years, one patient with polio 14 years following a tibial osteotomy and one patient 28 years following a tibial fracture. Ultra-short echo time pulse sequences (TE = 0.07 or 0.08 ms) were used with and without preceding fat suppression and / or long T2 component suppression pulses. Intravenous gadolinium (0.3 mmol/kg) was administered to one volunteer and three of the patients. Mean signal intensity (AU) was plotted against time following contrast enhancement. T1 and T2* values for cortical bone were determined and T1 was plotted against age.

Results A signal was obtained of cortical bone, periosteum and callus in all subjects. The injection of contrast enhanced the signal in all of these tissues. Distribution curves of gadolinium in cortical bone showed enhanced signal intensity following fracture. The signal was dependent on the type and severity of fracture and the time following fracture. There was a marked increase in signal in a hypertrophic mal-union 5 years following fracture and a moderate increase in signal was still detectable 28 years following fracture. Osteoporosis associated with polio reduced volume and signal of bone. T1 echo times ranged from 140 – 260 ms and increased significantly with age (P < 0.01). T2* ranged from 0.42 – 0.50 ms. Fat suppression and long T2 suppression increased the conspicuity of the periosteum.

Conclusion: Magnetic resonance imaging using UTE sequences is able to detect a signal from cortical bone for the first time. Cortical bone, callus and adult periosteum show a distinct signal following fracture with a characteristic time course. Measurements reflect the organic matrix rather than the inorganic crystals of bone. The T1 of cortical bone is very short and changes with age. The distribution curve of gadolinium can be established in cortical bone and is understood to reflect changes in blood flow. We present a pilot study to introduce a new MRI sequence, which at present a research tool, has potential for selected clinical application.

Introduction: Normal adult periosteum and cortical and produces no signal with typical bone has a short T₂ Magnetic Resonance pulse sequence echo times available in clinical practice. We wished to assess the value of using pulse sequences with a very short echo time to detect signal from periosteum and cortical bone.

Materials and Methods: Ultrashort echo time (UTE) pulse sequences (TE = 0.08 msec) were used with and without preceding fat suppression and/or long T₂ component suppression pulses. Later echo images and difference images produced by subtracting these from the first echo image were also obtained. Two volunteers and ten patients were examined, four of whom had contrast enhancement with intravenous Gadodiamide. Two sheep tibiae were also examined before and after stripping of the periosteum. The separated periosteum was also examined.

Results: The periosteum was seen on the sheep tibiae before stripping but there was only a faint signal adjacent to cortical bone afterwards and the removed tissue produced a high signal when examined separately. High signal regions were observed adjacent to cortical bone in the femur, tibia, spine, calcaneus, radius, ulna and carpal bones. Fat suppression and long T₂ suppression generally increased the conspicuity of these regions. The high signal regions were more obvious with contrast enhancement. Periosteum could generally be distinguished from susceptibility artifacts on difference images by its high signal on the initial image and its failure to increase in extent with images with increased TE’s. Signal in cortical bone was detected with UTE sequences in normal adults and patients. This signal was usually made more obvious by subtracting a later echo image from the first provided that the SNR was sufficiently high. Normal mean adult T₁’s ranged from 140 msec to 260 msec, and mean T₂’s ranged from 0.42 to 0.50 msec. Increased signal was observed after contrast enhancement in a normal volunteer and in all three patients in whom it was administered. Changes in signal in short T₂ components were seen in acute fractures in cortical bone and after fracture malunion. In a case of osteoporosis, bone volume and signal were reduced. Furthermore, in fractures increased signal was seen in the periosteum and this showed marked enhancement. Three weeks after fracture, tissue with properties consistent with periosteum was seen displaced from the bone by callus.

Discussion: The normal adult periosteum and cortex can be visualized with ultrashort TE sequences. Conspicuity is usually improved by fat suppression and the use of difference images. Use of subtraction images was useful for selectively demonstrating periosteal and cortical contrast enhancement and separating this from enhancement of surrounding blood. Obvious periosteal and cortical enhancement was seen after fractures. This novel MRI sequence images for the first time the soft tissue component of cortical bone and enables visualization of different haemodynamic situations.

Vascular Endothelial Growth Factor (VEGF) has been shown to stimulate angiogenesis in a number of tissues and, in addition, to possess direct vasoactive properties. Stimulation of blood flow and angiogenesis are important features of the fracture healing process, particular in the early phases of healing. Inadequate vascularity has been associated with delayed union after fracture. The periosteum, and in particular its osteogenic cambial layer, has been shown to be very reactive to fracture and to contribute substantially to fracture healing. Fracture haematoma contains a considerable concentration of VEGF and enhanced plasma levels are observed in patients with multiple trauma. VEGF has been suggested to play a role during new bone formation possibly providing an important link between hypertrophic cartilage, angiogenesis and consequent ossification. However, the expression of VEGF in normal periosteum and in periosteum close to a fracture has not been previously reported. We hypothesise that the expression of VEGF in long bone periosteum will show a distinct response to fracture.

We investigated the expression of VEGF in vivo in human periosteum, using immunocytochemistry to detect the expression of Factor VIII and VEGF protein respectively. Under prior approval from the local Ethics Committee, biopsies of periosteal tissues were collected from two distinct groups (1) control and (2) following long bone fracture. Patient age range was 16 – 45 years for both groups. Group 1 consisted of patients (n = 5) who underwent an elective orthopaedic procedure during which periosteum was disrupted. Group 2 patients (n = 8) had long bone fractures from which periosteal tissue was harvested close to the fracture site during internal fixation at various time points following fracture (24 hours to nine days).

In Group 1 the periosteum showed abundant but delicate blood vessels staining throughout for VEGF but there was no other visible staining of other structures or cells. In Group 2 the vasculature in the periosteum close to the fracture site demonstrated a characteristic, time-dependent course of expression of VEGF. At 24 and 48h following fracture the vasculature showed a heterogenous picture. The vessels in periosteum showed signs of activation: thickened endothelia and dilated lumina, but did not express VEGF. At 60h the vessels began to show signs of the presence of VEGF protein and by 4 days most periosteal vessels expressed VEGF. Also at this time, VEGF staining was visible in some of the stromal cells of the periosteum that was not seen in any of the earlier times. At 9 days VEGF was visible not only in the omnipresent vasculature, but now consistently in spindle shaped cells of fibroblastic appearance and chondrocytes throughout the early callus.

This study, though limited by the number of patients, shows for the first time the expression of VEGF in normal periosteum as well as in periosteum during fracture healing. Interestingly, activated vessels in the early healing phase show little expression of VEGF; however it is known that the fracture haematoma contains VEGF in abundance. It is possible that the vasoactive role of VEGF prevails in these early days. There may be a critical time point at around 48h post fracture following which angiogenesis begins and VEGF is expressed in the endothelium throughout the vessel wall. The study suggests an important role for VEGF in the regulation of fracture healing. VEGF is not only expressed in endothelial cells within the periosteum but also in fibroblast-like stem cells and chondrocytes throughout the early callus suggesting it may play an important role in both osteo- and angiogenesis

The tibial nutrient artery supplies 62% of cortical blood flow in the diaphysis and normal blood flow is centrifugal (Willans 1987). Intramedullary reaming destroys the nutrient artery and injures the endosteal surface of the cortex. Trueta (1974) suggested that the direction of blood flow can reverse from centrifugal to centripetal after loss of the endosteal supply. We examined this hypothesis by measuring cortical and periosteal blood flow after intramedullary reaming of the tibia in eight sheep, using 57Co radiolabelled microspheres. The unreamed contralateral tibiae served as a control group. Thirty minutes after reaming there was no significant change in cortical blood flow, but a sixfold increase in the periosteal flow. Our study confirms Trueta's hypothesis; after trauma or in other pathological states, flow can become centripetal.