Background:

The aim of this study was to review the surgical complications and clinical outcomes of patients with Pilon fractures treated with Ilizarov frames.

Interbody fusion aims to treat painful disc disease by demobilising the spinal segment through the use of an interbody fusion device (IFD). Diminished contact area at the endplate interface raises the risk of device subsidence, particularly in osteoporosis patients. The aim of the study was to ascertain whether vertebral body (VB) cement augmentation would reduce IFD subsidence following dynamic loading. Twenty-four human two-vertebra motion segments (T6–T11) were implanted with an IFD and distributed into three groups; a control with no cement augmentation; a second with PMMA augmentation; and a third group with calcium phosphate (CP) cement augmentation. Dynamic cyclic compression was applied at 1Hz for 24 hours in a specimen specific manner. Subsidence magnitude was calculated from pre and post-test micro-CT scans. The inferior VB analysis showed significantly increased subsidence in the control group (5.0±3.7mm) over both PMMA (1.6±1.5mm, p=.034) and CP (1.0±1.1mm, p=.010) cohorts. Subsidence in the superior VB to the index level showed no significant differences (control 1.6±3.0mm, PMMA 2.1±1.5mm, CP 2.2±1.2mm, p=.811). In the control group, the majority of subsidence occurred in the lower VB with the upper VB displaying little or no subsidence, which reflects the weaker nature of the superior endplate. Subsidence was significantly reduced in the lower VB when both levels were reinforced regardless of cement type. Both PMMA and CP cement augmentation significantly affected IFD subsidence by increasing VB strength within the motion segment, indicating that this may be a useful method for widening indications for surgical interventions in osteoporotic patients.

Metatarsal fractures are extremely common injuries accounting for 10% of all fractures seen in our accident and emergency departments (3). The vast majority can be treated conservatively. There is no standardised treatment, but it is commahplace to immobilise the foot and ankle joint in a below-knee back-slab, full cast or functional brace for a period of up to 6 weeks, weight-bearing the patient as pain allows. This practice is time-consuming and expensive, not to mention debilitating, and carries a morbidity risk to the patient.

We describe a simple, effective and cheap treatment method for metatarsal fracture management using the functional forefoot-offloading shoe (FOS). This is clinically proven to offload pressure on the metatarsals and is commonly used in both elective forefoot surgery and in diabetic patients.

Between January and September 2009, we identified 57 patients attending our fracture clinic with new metatarsal fractures. 28 met our inclusion criteria.

All patients reported a significant improvement in their pain

At Injury – mean 8.21 out of 10 (range 4-10)

After FOS fitting - mean 2.92 out of 10 (range 0-6)

The forefoot-offloading shoe is an excellent alternative to plaster casting or functional boot immobilisation, offering high patient satisfaction, an excellent outcome and a considerable cost-saving to the hospital trust.

Background: Knee prosthesis design is being constantly altered in a bid to imitate kinematics of the normal knee. It is hoped that this will improve the wear characteristics and performance of the implant. The ‘Medial Pivot’ knee has a characteristic geometry and is expected to lower contact stresses on the tibial surface and ease rehabilitation while providing greater stability.

We conducted a study comparing the midterm outcome of the Medial Pivot knee (MP) to the Posterior Stabilised (PS) knee.

Materials and Methods: Over a 3 year period, 312 knee replacements were carried out of which 124 were MP and 188 were PS. 100 patients from each of the 2 groups were called for review. Demographic data, age at operation, time since surgery and ASA grading were noted. Postoperative knee function was assessed using the American Knee Society (AKS) and Oxford Knee (OK) scores and the scores were compared between the 2 groups. Individual functional parameters were also compared.

Results: 38 patients with 42 replaced knees in the MP group and 43 patients with 52 replaced knees in the PS group were reviewed. The 2 groups were comparable in terms of gender of patients and age at operation and were followed up to a mean 31 months. For the MP group the mean AKS knee assessment score was 77/100, AKS function score was 75/100 and OK Score was 23/60. For the PS group the corresponding values were 81/100, 77/100 and 22/60. The differences in scores between the groups were not statistically significant. Only active and passive knee extension was better following MP Arthroplasty than PS arthroplasty (p< 0.05). Although the mean flexion was better following the PS arthroplasty, this was not statistically significant.

Conclusion: Our study has shown that the midterm outcome for the Medial Pivot knee system did not show any distinct advantage over the Posterior Stabilised knee system in terms of knee pain & function.

Introduction: Cell adhesion to titanium alloy implants is important in osseointegration [1,2] and attachment of the soft tissues to skin penetrating implants e.g. external fixator pins and Intraosseous Transcutaneous Amputation Prostheses [3,4]. Cell adhesion can be assessed using cell area data and immunolocalisation of focal contact proteins e.g. vinculin; however no method of assessing biophysical attachment is performed routinely. Cell adhesion can be enhanced with adhesion proteins including fibronectin (Fn)[5]. We have previously shown that covalently binding Fn to titanium also increases cell adhesion, and produces a more robust protein coating [6]. However the strength of adhesion of cells to this coating has not been measured. Our hypothesis was that biophysical cell adhesion measured using novel radial flow apparatus would correlate with cell area and focal contact data and that covalently bound fibronectin substrates would increase cell adhesion compared with adsorbed and uncoated controls.

Method: Dermal fibroblasts were cultured for 1, 4, and 24 hours on 30mm and 10mm diameter polished titanium alloy discs (n = 6). Cells on 30mm discs were calcein stained and subjected to shear stress in a submerged, media filled, custom-made radial flow apparatus at 37¬C at 1.66ml/s for 15s. Cells were fixed in 10% formal saline and photographs were taken using a tangential light source. Fluorescent microscopy was performed at 2mm intervals along two perpendicular diameters. Using image analysis, the central cell free zone was measured and radial distance and shear stress calculated. Cells on 10mm discs were fixed, permeablised and vinculin stained (mouse vinculin antibody (1:200) 2hrs; FITC mouse antibody (1:100)1hr). Images were analyzed with a Zeiss microscope linked to image analysis software and the number of focal contacts were counted per cell area. The medians of the radial flow data were compared with data for cell area and focal contact production at the same time points using Spearman¡s regression correlation. This method was subsequently used to compare cell adhesion at one hour with adsorbed and covalently bound Fn substrates (10¥ìg/disc).

Results/Discussion: The shear strength of cells increased between 4 and 24hrs (p=0.002) on polished untreated control substrates. Attachment values (dynes/cm2) were 84.90 (73.98–97.19), 96.30 (91.66–100.89), and 136.69 (134.68–140.30) for 1, 4 and 24 hours respectively. At 1hr, covalently bound Fn (509.90 dynes/cm2 (490.55–528.49) significantly increased cell adhesion compared with adsorbed Fn(434.45 dynes/cm2(385.25–465.62)) and control substrates(p=0.002). There was significant correlation between shear stress and focal contacts/cell (1.00(p< 0.01)) and focal contacts/cell area (0.900(p=0.037)), but not cell area (0.600(p=0.285)).

Conclusion: Radial flow measurement is a useful direct method to quantify cell adhesion to orthopaedic implants and correlates well with other methods of measurement. Covalently bound Fn significantly increases biophysical cell attachment compared with adsorbed and uncoated controls.