Low back pain resulting from Interertebral disc (IVD) degeneration is a serious worldwide problem, with poor treatment options available. Notochordal (NC) cells, are a promising therapeutic cell source with anti-catabolic and regenerative effect. However, their behaviour in the harsh degenerate environment is unknown.

Porcine NC cells (pNCs), and Human NP cells from degenerate IVDs were cultured in alginate beads to maintain phenotype. Cells were cultured alone or in combination, or co-stimulated with notochordal cell condition media (NCCM), in media to mimic the healthy and degenerate disc environment, together with controls for up to 1 week. Following culture viability, qPCR and proteomic analysis using Digiwest was performed.

A small increase in pNC cell death was observed in degenerated media compared to standard and healthy media, with a further decrease seen when cultured with IL-1β. Whilst no significant differences were seen in phenotypic marker expression in pNCs cultured in any media at gene level (ACAN, KRT8, KRT18, FOXA2, COL1A1 and Brachyury). Preliminary Digiwest analysis showed increased protein production for Cytokeratin 18, src and phosphorylated PKC but a decrease in fibronectin in degenerated media compared to standard media. Human NP cells cultured with NCCM, showed a decrease in IL-8 production compared to human NP cells alone when cultured in healthy media. However, gene expression analysis (ACAN, VEGF, MMP3 and IL-1β) demonstrated no significant difference between NP only and NP+NCCM groups.

Studying the behaviour of the NCs in in vitro conditions that mimic the in vivo healthy or degenerate niche will help us to better understand their potential for therapeutic approaches. The potential use of NC cell sources for regenerative therapies can then be translated to investigate the potential use of iPSCs differentiated into NC cells as a regenerative cell source.

Low back pain is strongly associated with degeneration of the intervertebral disc (IVD). During degeneration, altered matrix synthesis and increased matrix degradation, together with accompanied cell loss is seen particularly in the nucleus pulposus (NP). It has been proposed that notochordal (NC) cells, embryonic precursors for the cells within the NP, could be utilized for mediating IVD regeneration. However, injectable biomaterials are likely to be required to support their phenotype and viability within the degenerate IVD. Therefore, viability and phenotype of NC cells were analysed and compared within biomaterial carriers subjected to physiological oxygen conditions over a four-week period were investigated.

Porcine NC cells were incorporated into three injectable hydrogels: NPgel (a L-pNIPAM-co-DMAc hydrogel), NPgel with decellularized NC-matrix powder (dNCM) and Albugel (an albumin/ hyaluronan hydrogel). The NCs and biomaterials constructs were cultured for up to four weeks under 5% oxygen (n=3 biological repeats). Histological, immunohistochemical and glycosaminoglycans (GAG) analysis were performed to investigate NC viability, phenotype and extracellular matrix synthesis and deposition.

Histological analysis revealed that NCs survive in the biomaterials after four weeks and maintained cell clustering in NPgel, Albugel and dNCM/NPgel with maintenance of morphology and low caspase 3 staining. NPgel and Albugel maintained NC cell markers (brachyury and cytokeratin 8/18/19) and extracellular matrix (collagen type II and aggrecan). Whilst Brachyury and Cytokeratin were decreased in dNCM/NPgel biomaterials, Aggrecan and Collagen type II was seen in acellular and NC containing dNCM/NPgel materials. NC containing constructs excreted more GAGs over the four weeks than the acellular controls.

NC cells maintain their phenotype and characteristic features in vitro when encapsulated into biomaterials. NC cells and biomaterial construct could potentially become a therapy to treat and regenerate the IVD.

Backgrounds and aim

Low back pain resulting from Intervertebral disc (IVD) degeneration is a serious worldwide problem, with poor treatment options available. Notochordal (NC) cells, are a promising therapeutic cell source with anti-catabolic and regenerative effect, however, their behaviour in the harsh degenerate environment is unknown. Thus, we aimed to investigate and compare their physiological behaviour in in vitro niche that mimics the healthy and degenerated intervertebral disc environment.

Objectives

Low back pain is strongly associated with degeneration of the intervertebral disc (IVD). During degeneration, altered matrix synthesis and increased matrix degradation, together with accompanied cell loss is seen particularly in the nucleus pulposus (NP). It has been proposed that notochordal (NC) cells, embryonic precursors for the cells within the NP, could be utilized for mediating IVD regeneration. However, injectable biomaterials are likely to be required to support their phenotype and viability within the degenerate IVD. Therefore, viability and phenotype of NC cells were analysed and compared within biomaterial carriers subjected to physiological oxygen conditions over a four-week period were investigated.

Introduction and Objective

Intervertebral disc (IVD) degeneration accompanying with low back pain is a serious worldwide problem. Even though, surgical treatments are available for pain relief, there is an urgent need to establish enduring cell-based remedies. Notochordal (NC) cells as the ancestor of nucleus pulposus (NP) cells in human IVD are a promising therapeutic target. It has been reported that the loss of NC cells after childhood could promote the onset of disc degeneration. Thus, we firstly, aimed to optimise the culture of NC cells in vitro without using the FCS in alginate (3D) culture systems, secondly, investigate their behaviour in healthy and degenerate niche and lastly, co-culture these cells with degenerated NP cells to assess their regeneration potentials.

Background

The advent of EOS imaging has offered clinicians the opportunity to image the whole skeleton in the anatomical standing position with a smaller radiation dose than standard spine roentgenograms. It is known as the fifth modality of imaging. Current NICE guidelines do not recommend EOS scans over x-rays citing: “The evidence indicated insufficient patient benefit in terms of radiation dose reduction and increased throughput to justify its cost”.

Heterotopic ossification is the formation of lamellar bone in soft tissues and is a common complication of high-energy combat injury. This disabling condition can cause pain, joint ankylosis, and skin ulceration in the residua of amputees. This project is aimed at developing a novel treatment to dissolve hydroxyapatite in heterotopic ossification and prevent the crystallisation of this this mineral at sites of ectopic bone formation. Previously reported results demonstrated that hexametaphosphate could dissolve hydroxyapatite at physiological pH. Further work has been undertaken to investigate the mechanism of this dissolution and establish a means of temporal control of action. In addition, physicochemical analyses of samples of human heterotopic ossification have yielded important insights into the nature of this pathological tissue. Techniques include mapped micro X-ray fluorescence, mapped Raman spectroscopy, scanning electron microscopy, and micro computed tomography. Formulation engineering work has begun in order to develop an appropriate delivery vehicle for this agent. This includes rheological testing and hexametaphosphate elution profiles. Finally, micro CT analysis has shown that hexametaphosphate is able to dissolve human heterotopic ossification tissue. In summary, this work has moved us closer towards our goal of a novel injectable agent for the treatment and prevention of heterotopic ossification.

Background

Bone is a hierarchically structured hard tissue that consists of approximately 70 wt% low-crystallinity hydroxyapatite. Intricate tubular channels, such as Haversian canals, Volkman's canals, and canaliculi are a preserved feature of bone microstructure. These structures provide pathways for vasculature and facilitate cell-to-cell communication processes, together supporting viability of cellular components and aiding in remodeling processes. Unfortunately, many commercial bone augmentation materials consist of highly crystalline phases that are absent of the structuring present within the native tissue they are replacing. This work reports on a the development of a novel bone augmentation material that is able to generate biologically analogous tubular calcium phosphate mineral structures from hydrogel-based spheres that can be packed into defects similar to those encountered in vivo.

Background

We reproduced a frequently cited study performed at our University Hospital that was published in the British Medical Journal in 1981 assessing the extent of “snow and ice” fractures during the winter period.

Background

Calcium orthophosphates, such as hydroxyapatite (Ca5(PO4)3OH) (HA), have long been employed as bone graft materials. Recent work has suggested that calcium pyrophosphate (Ca2P2O7) (CaPy) may strongly stimulate bone deposition. In this study we compare calcium orthophosphate and pyrophosphate precipitates as suitable bone regeneration materials. As well as HA, two forms of pyrophosphate precipitate were compared in this work: amorphous calcium pyrophosphate (amCaPy) and star particle calcium pyrophosphate (stCaPy).

At first-stage revision surgery for infection of total knee arthroplasties, antibiotic-impregnated cement spacers are frequently implanted. Two types of cement spacers are commonly used, “static” and “articulating” cement spacers. Advocates of cement spacers state that they deliver high doses of antibiotics locally, increase patient comfort, allow mobility and provide joint stability. They also minimize contracture of collateral ligaments, thereby facilitating re-implantation of a definitive prosthesis at a later stage. The use of these cement spacers, however, are not without significant complications, including patella tendon injuries.

We describe a series of three patients who sustained patella tendon injuries in infected total knee arthroplasties following the use of a static cement spacer at first-stage knee revision.

The patella tendon injuries resulted in significant compromise to wound healing and knee stability requiring multiple surgeries. The mid-term function was poor with an Oxford score at 24 months ranging from 12–20

Based on our experience, we advise caution in the use of static cement spacer blocks. If they are to be used, we recommend that they should be keyed in the bone to prevent patella tendon injuries.

Honey has been used as a topical antiseptic for at least 5,000 years. SurgiHoney is a CE licensed sterile product, which has been proven to be non-toxic and effective when used topically in the treatment of chronically infected wounds. The key difference from other medical grade honey is the broad spectrum antimicrobial characteristics with activity against Gram +ve, Gram –ve and multi-resistant organisms. Its novel role against the bacterial bioburden and biofilm associated with periprosthetic infections around total knee arthroplasties (TKA's) is therefore considered.

SurgiHoney was used as an implant coating immediately prior to wound closure after implantation of salvage endoprosthesis for multiply revised, infected TKA's undergoing staged reconstruction.

We report a consecutive series of multi-revised, infected revision TKA's where SurgiHoney was used as an active antimicrobial coating. We discuss its intra-operative application and early clinical outcomes.

The use of Surgihoney as a novel anti-microbial is established in the management of complex wound infections. This is the first reported use of SurgiHoney as a deep, implant coating in the salvage of prosthetic joint infection.

Joint degeneration may make a total knee arthroplasty (TKA) a requirement for pain relief and function. However, the presence of ipsilateral limb osteomyelitis (OM) makes surgical management extremely challenging.

We report the experience of a high volume revision knee surgeon managing ipsilateral limb multi resistant OM and the outcome of subsequent TKA.

Four consecutive patients were identified who had either ipsilateral femoral or tibial chronic osteomyelitis treated prior to undergoing TKA. Surgery to eradicate the osteomyelitis involved a Lautenbach compartmental debridement, and where necessary, healing by secondary intention. The decision to proceed to a TKA was based on history, clinical examination and radiological findings of advanced osteoarthritic change.

The patients had a mean age of 50 years. They had a background of multi-organism OM and underwent single-stage TKAs at an average of 63 months following eradication of the underlying OM.

Three patients did well but had complications associated with poor skin and soft tissues, and abnormal bone anatomy. One patient developed an infection and following a re-revision had an arthrodesis.

The results for the four cases are summarised in Table 1.

We have highlighted that patients with ipsilateral limb multi resistant OM are a difficult cohort to manage.

A common step to revision surgery for infected total knee replacement (TKR) is a thorough debridement. Whilst surgical and mechanical debridement are established as the gold standard, we investigate a novel adjuvant chemical debridement using an Acetic Acid (AA) soak that seeks to create a hostile environment for organisms, further degradation of biofilm and death of the bacteria.

We report the first orthopaedic in vivo series using AA soak as an intra-operative chemical debridement agent for treating infected TKR's. We also investigate the in vitro efficacy of AA against bacteria isolated from infected TKR's.

A prospective single surgeon consecutive series of patients with infected TKR were treated according to a standard debridement protocol. Patients in the series received sequential debridement of surgical, mechanical and finally chemical debridement with a 10 minute 3% AA soak.

In parallel, we isolated, cultured and identified bacteria from infected TKR's and assessed the in vitro efficacy of AA. Susceptibility testing was performed with AA solutions of different concentrations as well as with a control of a gentamicin sulphate disc. The effect of AA on the pH of tryptone soya was also monitored in an attempt to understand its potential mechanism of action.

Physiological responses during the AA soak were unremarkable. Intraoperatively, there were no tachycardic or arrythmic responses, any increase in respiratory rate or changes in blood pressure. This was also the case when the tourniquet was released. In addition, during the post-operative period no increase in analgesic requirements or wound complications was noted. Wound and soft tissue healing was excellent and there have not been any early recurrent infections at mean of 18 months follow up.

In vitro, zones of inhibition were formed on less than 40% of the organisms, demonstrating that AA was not directly bactericidal against the majority of the clinical isolates. However, when cultured in a bacterial suspension, AA completely inhibited the growth of the isolates at concentrations as low as 0.19%v/v.

This study has shown that the use of 3% AA soak, as part of a debridement protocol, is safe. Whilst the exact mechanism of action of acetic acid is yet to be determined, we have demonstrated that concentrations as low as 0.19%v/v in solution in vitro is sufficient to completely inhibit bacterial growth from infected TKR's.

Summary Statement

Calcium phosphate (CaP) particles have attracted great interest as transfection reagents, yet little is known about their mechanism of internalisation. We report live cell time-course tracking of CaP particles during internalisation and the influence of Ca:P ratio on transfection efficiency.

Introduction

Total Knee Arthroplasty (TKA) aims to deliver relief from pain and restore normal function. Unfortunately, a significant cohort of patients report poor outcomes.

Introduction

Osteoarthritis (OA) represents a leading cause of disability and a growing burden on healthcare budgets. OA is particularly vexing for young, active patients who have failed less invasive therapies but are not yet candidates for arthroplasty. Often, patients suffering in this wide therapeutic gap face a debilitating spiral of disease progression, increasing pain, and decreasing activity until they become suitable arthroplasty patients. An implantable load absorber was evaluated for the treatment of medial knee OA in this patient population.

Joint overload has been cited as a contributor to OA onset or progression. In response, the KineSpring® System (Moximed, Inc, USA) has been designed to reduce the load acting on the knee. The absorber is implanted in the subcutaneous tissue without violating the joint capsule, thus preserving the option of future arthroplasty. The implant is particularly useful for young, active patients, given the reversibility of the procedure and the preservation of normal flexibility and range of motion.

BACKGROUND

High tibial Osteotomy (HTO) realigns the forces in the knee to slow the progression of osteoarthritis. This study relates the changes in knee joint biomechanics during level gait to glutamate signalling in the subchondral bone of patients pre and post HTO. Glutamate transmits mechanical signals in bone and activates glutamate receptors to influence inflammation, degeneration and nociception in arthritic joints. Thus glutamate signalling is a mechanism whereby mechanical load can directly modulate joint pathology and pain.

Unique progenitor cells have been identified recently and successfully cultured in vitro from human articular cartilage. These cells are able to maintain chondrogenic potential upon extensive expansion. In this study, we have developed a sheep, ex-vivo model of cartilage damage and repair, using these progenitor cells. This study addresses the question can such a model be used to determine factors required for progenitor cell proliferation, differentiation and integration of matrix onto bone. The hypothesis was that sheep allogenic cartilage derived progenitor cells could regenerate artificially damaged sheep articular cartilage in an osteochondral culture model. Progenitor cells were derived from ovine articular cartilage using a differential adhesion assay to fibronectin and expanded clonally. These clonal cells were marked with lentiviral vectors derived from the Human Immunodeficiency Virus-1. When a self-inactivating lentiviral vector encoding a ubiquitous phosphoglycerate kinase promoter, driving a Green Fluorescent Protein (GFP) reporter gene, was used to transduce these cells, up to 80% of these progenitor cells expressed GFP. Normal sheep medial femoral condyles containing about 2mm thick sub-condral bone were obtained and 4mm circular defects created on the cartilage surface using a biopsy punch. Condyles were cultured for two weeks in vitro with GFP labelled progenitor cells within a fibrin glue scaffold (Tisseel Lyo) and matrix production (collagen) as determined by spatially offset Raman spectroscopy and immunohistochemistry was demonstrated. Progenitor cells were able to proliferate and differentiate into collagen producing cells. Such an ex-vivo model system is an effective tool for the analysis of cartilage repair from various sources of stem cells. These ex-vivo experiments and variations on defect type, size, titration of scaffold and progenitor cell numbers requirements can further be used as a basis for screening prior to in vivo experiments.

Hyaline cartilage defects are a significant clinical problem for which a plethora of cartilage repair techniques are used. One such technique is cartilage replacement therapy using autologous chondrocyte or mesenchymal stem cell (MSC) implantation (ACI). Mesenchymal stem cells are increasingly being used for these types of repair technique because they are relatively easy to obtain and can be expanded to generate millions of cells. However, implanted MSCs can terminally differentiate and produce osteogenic tissue which is highly undesirable, also, MSCs generally only produce fibrocartilage which does not make biomechanically resilient repair tissue, an attribute that is crucial in high weight-bearing areas. Tissue-specific adult stem cells would be ideal candidates to fill the void, and as we have shown previously in animal model systems [Dowthwaite et al, 2004, J Cell Sci 117;889], they can be expanded to generate hundreds of millions of cells, produce hyaline cartilage and they have a restricted differential potential. Articular chondroprogenitors do not readily terminally differentiate down the osteogenic lineage.

At present, research focused on isolating tissue-specific stem cells from articular cartilage has met with modest success. Our results demonstrate that using differential adhesion it is possible to easily isolate articular cartilage progenitor populations from human hyaline cartilage and that these cells can be subsequently expanded in vitro to a high population doubling whilst maintaining a normal karyotype. Articular cartilage progenitors maintain telomerase activity and telomere length that are a characteristic of progenitor/stem cells and differentiate to produce hyaline cartilage.

In conclusion, we propose the identification and characterisation of a novel articular cartilage progenitor population, resident in human cartilage, which will greatly benefit future cell-based cartilage repair therapies.

Statement of Purpose

The UK and Australian clinical experience of an implantable load absorber was reviewed for knee OA patients who have exhausted conservative care, but are not ideal candidates for HTO or arthroplasty due to age, activity level, obesity, or disinclination.

Background

Patellofemoral replacement is an established intervention in selected patients with severe isolated patellofemoral osteoarthritis. FPV (Wright Medical, UK) is a third generation patellofemoral arthroplasty implant and is the second most used after AVON in National Joint Registry for England and Wales. Reports of survivorship and functional of this implant are scarce in literature.

Hyaline cartilage defects are a significant clinical problem for which a plethora of cartilage repair techniques are used. One such technique is cartilage replacement therapy using autologous chondrocyte or mesenchymal stem cell (MSC) implantation (ACI). Mesenchymal stem cells are increasingly being used for these types of repair technique because they are relatively easy to obtain and can be expanded to generate millions of cells. However, implanted MSCs can terminally differentiate and produce osteogenic tissue which is highly undesirable, also, MSCs generally only produce fibrocartilage which does not make biomechanically resilient repair tissue, an attribute that is crucial in high weight-bearing areas. Tissue-specific adult stem cells would be ideal candidates to fill the void, and as we have shown previously in animal model systems [Dowthwaite et al, 2004, J Cell Sci 117;889], they can be expanded to generate hundreds of millions of cells, produce hyaline cartilage and they have a restricted differential potential. Articular chondroprogenitors do not readily terminally differentiate down the osteogenic lineage.

At present, research focused on isolating tissue-specific stem cells from articular cartilage has met with modest success. Our results demonstrate that using differential adhesion it is possible to easily isolate articular cartilage progenitor populations from human hyaline cartilage and that these cells can be subsequently expanded in vitro to a high population doubling whilst maintaining a normal karyotype. Articular cartilage progenitors maintain telomerase activity and telomere length that are a characteristic of progenitor/stem cells and differentiate to produce hyaline cartilage.

In conclusion, we propose the identification and characterisation of a novel articular cartilage progenitor population, resident in human cartilage, which will greatly benefit future cell-based cartilage repair therapies.

In recent years tribological development of knee replacement impants has beeen introduced with several benefits. However, concomitant problems were noticed following widespread use.

High-flexion total knee replacement (PFC RPF DePuy) has been developed with a view to improve flexion and the design is expected to have a better patello-femoral biomechanics. However, high secondary patella resurfacing rate has been noticed in the current series.

We have retrospectively reviewed 119 knees in 96 patients who underwent RPF knee replacement with selective patellar resurfacing from 2006 to 2010 by the senior author. 71 were performed without primary resurfacing while 48 in knees patella was resurfaced primarily due to significant symptomatic arthritic changes. Majority were females (57 versus 39 males). Average follow-up period was 37 (12-62) months.

Twelve (16.9%) knees were subjected to secondary resurfacing due to continuing anterior knee pain. Average time from primary total knee replacement to secondary resurfacing was 18 months (8-35). Most of the patients were satisfied following the secondary resurfacing.

Mean Oxford Knee Score in the group where the patella was resurfaced primarily was 33.1 (9-48), in the group where the patella was not resurfaced 32.8 (11-47), in the secondary resurfacing group 31.8 (14-43) and in the revision group 20.5 (16-25).

RPF knee replacements in our series have a considerably higher rate of secondary patellar resurfacing as compared with published literature. We recommend primary patellar resurfacing of all RPF knee replacements to avoid this problem. Further analysis of the prosthetic design would be beneficial in relation to clinical outcome.

No of patients-96

Total no of knee-118

Av age-66.5

Females-57

Males-39

Patella not resurfaced- 73

Resurfaced-45

Revised-10(13.7%)

Revision to TKR (TC3) for different reason-3(2.54%)

Average time from primary to secondary resurfacing-

Glutamate is a neurotransmitter that transmits mechanical signals in bone (1) and activates glutamate receptors and transporters, in bone, cartilage, meniscus and synovium (2). Glutamate receptor activation influences inflammatory, degenerative and nociceptive pathways in arthritic joints (2). Thus glutamate signalling is a mechanism whereby mechanical load can directly influence joint pathology and pain. We have investigated components of glutamate signalling in the subchondral bone of patients with osteoarthritis to determine which are expressed and whether this varies in anatomical regions subject to different loads. Subchondral bone was sampled from tibial cuts derived from total knee arthroplasty (n=2, TKR, Kellgren Lawrence grade 3) and from tibial drill hole sites from high tibial osteotomy (n=5, HTO, KL grades 2 and 3) for osteoarthritis. RNA was extracted, reverse transcribed and RT-PCR performed for a housekeeping gene GAPDH, a glutamate transporters (EAAT-1, EAAT1ex9skip), glutamate receptors (NR2A and KA1), a bone matrix protein, osteocalcin, and signaling molecules (osteoprotegerin [OPG], RANKL). We found differential mRNA expression in different regions of subchondral bone. In one TKR patient, EAAT-1 expression was significantly reduced in the anterior zone versus the middle or posterior zones of the tibial plateau (ANOVA, p<0.001). HTO bone cores were subdivided medial/lateral and anterior/posterior. Good quality RNA was obtained from bone cores removed from drill holes during HTO surgery, with GAPDH, osteocalcin, EAAT-1, EAAT1ex9skip, NR2A, KA1, OPG and RANKL mRNA expression detected. In one patient, comparison of gene expression in bone cores obtained pre and post HTO revealed that EAAT1ex9skip was rarely detected in post-op bone whereas KA1 was rare in pre-op bone. This differential mRNA expression may be due to the altered loading through the joint caused by the osteotomy, although these on/off differences need to be quantified to confirm this.

We have shown that glutamate transporters and receptors are expressed in human subchondral bone. Activation of these receptors and transporters by the increased synovial fluid concentrations of glutamate released in arthritis will influence pathological changes and nociception. In some patients, glutamate transporter mRNA expression appears to vary with anatomical location in bone, or after HTO surgery, consistent with our original discovery of this transporter as mechanically-regulated in bone (1). If glutamatergic signaling is mechanically regulated in the human knee, this will vary during arthritic disease progression and after joint realignment, providing a direct mechanism linking mechanical loading through the joint to pathology and pain in arthritis.

The simple dictum of the late Prof. Alf Nachemson was that ‘surgery should very rarely, if ever, be performed in adult scoliotic patients for lumbar curves when pain is the most serious problem’. Today, the complexity of intercurrent neural symptoms, the advancing age of the population and the increasing demands and expectations of modern living require a somewhat more flexible approach to this increasingly common problem.

Treatment of adult deformity has improved along with our understanding of the radiological features of the condition most likely to be associated with disabling pain and also with our appreciation of the adverse significance of patient co-morbidity. In those patients where conservative measures have failed and where an acceptable quality of life has been lost, surgical management may be undertaken, but must address all the symptomatic aspects of the deformity in one episode of care.

Primary objectives include the restoration of satisfactory sagittal plane correction using the minimum number of operated levels whilst providing adequate spinal stability. Meticulous preoperative planning from a clinical and radiological perspective maximises the possibility of a satisfactory outcome and in this regard patient expectation is of prime importance. The questions of operative approach and levels of fixation are ever present and recent advances in our understanding of distal end fixation are worthy of consideration.

Finally, exemplary cases and our series of 23 patients undergoing surgical treatment of adult scoliosis will be presented. Mean coronal curve correction by anteroposterior approach was 60.4% and by posterior only approach 40.3%.

Patient satisfaction was 77.8% by combined approach and 58.9% by posterior only approach. The rate of reoperation was 66.7% for posterior surgery alone and 11.1% for combined approach corrections.

Tapping the radial side of the wrist normally elicits a reflex contraction producing elbow flexion, wrist extension and wrist radial deviation. An abnormal response, consisting of finger flexion when performing this manoeuvre is known as the inverted radial (supinator) reflex (IRR). The significance of this reflex in asymptomatic subjects is unknown.

To document the frequency of the IRR in an asymptomatic population and to identify any presymptomatic pathology in those subjects.

The study group consisted of patients and staff at the senior author's institution. Patients were taken from clinics where the complaints were of lower limb symptoms. Subjects were excluded if they had any history of neck pain or stiffness or if they had any subjectively abnormal sensation. The radial reflex was elicited with a tendon hammer. Those subjects with an IRR were asked to attend for a MRI scan of the cervical spine to investigate for any abnormality.

47 subjects were studied. There were 8 subjects who displayed an IRR. In 4 subjects the IRR was unilateral and in 4 bilateral. Seven subjects consented to further investigation by MRI. The average age of these patients was 36 years.

The MRI scans revealed normal appearances in 6 cases. There was no cord signal abnormality in any case.

The IRR occurred with a frequency of 17% in the study group. There was no significant cervical pathology identified in these subjects.

In young asymptomatic patients, the presence of an inverted radial reflex is of no diagnostic relevance.

AO Spine Reference Centre & Institute of Health & Biomedical Innovation, Queensland University of Technology, Brisbane, Australia

Traumatic spinal cord injury (SCI) is a devastating condition with no curative therapy. Pro-inflammatory therapy has been suggested recently to try and reduce the inhibitory glial scar and promote neural regeneration and healing. The aim of this study is to investigate the potential of sustained delivery of angiogenic/pro-inflammatory growth factors to reduce the secondary degeneration after spinal cord injury.

Adult male Wistar Kyoto rats (200-300g; 12-16weeks old) were subjected to cord hemisections via a T10 laminectomy. Animals were randomised to treatment or control groups after the spinal cord injury had been induced. Treatment consisted of implantation of a mini-osmotic pump capable of delivering 5 micrograms vascular endothelial growth factor (VEGF) and 5 micrograms platelet-derived growth factor (PDGF), via a catheter, to the site of the lesion, over 7 days(n=6). Control animals were subjected to either cord lesion only (n=6) or lesion plus mini-pump delivering PBS (phosphate-buffered saline) solution (n=6). Rats were sacrificed at one month and the spinal cords were harvested and examined by immunohistology, using anti-neurofilament-200 and anti-Glial Acidic Fibrillary Acidic Protein (GFAP) antibodies.

RESULTS: Active treatment spinal cords showed a higher level with aboration of the axonal filament through the defect and more dense neurofilament-200 staining at the lesion site compared to both control groups. The treatment also showed the elevated presence of activated microglia in the lesion, whilst distal to the lesion the microglia and astrocytes retained an unreactive phenotype.

Pro-inflammatory therapy in the rat spinal cord-injury model showed favourable histological findings after sustained delivery of PDGF and VEGF

Purpose: We conducted a study of 72 hammer toes treated with proximal interphalangaeal joint (PIPJ) fusions with a Stayfuse implant. The aim of the study was to access the clinical results of PIPJ fusion carried out with Stayfuse implants.

Method: There were 10 males and 62 females. Average age was 52 years. Twelve cases had bilateral and 60 cases had unilateral foot involvement. Fifty-two second and 20 third toes were operated on. Mean follow up was twelve months. The results were assessed clinically, radiologically and with the American orthopaedic foot and ankle surgery society (AOFAS) score.

Results: All the joints fused clinically except two. There were ten PIPJ’s which did not fuse radiologically. The AOFAS score improved from 42 preoperativley to 84 post operatively. There were two cortical breeches of the proximal phalanx, one implant breakage and one case of dissociation of the components of the implant at six weeks after the surgery, with a recurrence of deformity. There were two patients who complained of over-straight toes. Fifty-two patients were very satisfied with the procedure, seventeen satisfied and three patients were unsatisfied.

Conclusion: We conclude that the Stayfuse is safe, reliable method to correct PIPJ deformity, although there is a learning curve. The main advantages of the implant are that there is no postoperative implant exposure, no violation of healthy joints, no risk of pin tract infection, rotational and angular stability, early rehabilitation and a high patient satisfaction. The disadvantages of the implant are dissociation of the components and the difficulty of removal, if this is needed.

We undertook a prospective randomised trial to determine the outcome of locked intramedullary fixation vs. plating of displaced shortened mid-shaft clavicle fractures. The primary outcome measure was the Constant shoulder score, while secondary outcome measures included the Oxford shoulder score, union rate, and complication rates.

Thirty-two patients were recruited to the trial; 17 randomised to locked intramedullary fixation and 15 randomised to plating. Mean age was 29.3years (13 to 53 years). Mean follow-up was 12.4 months (5 to 28 months). There was no significant difference in Constant scores (p = 0.365) and no significant difference in Oxford scores (p = 0.686). There was 100% union in both groups. In the intramedullary group, there was one case of soft tissue irritation that settled after the pin was removed, one pin backed out and had to be revised with another pin. There were three superficial wound infections resulting in plate removal and 8 plates (53%) were removed.

Locked intramedullary fixation and plating are equally effective in the management of shortened displaced mid-shaft clavicle fractures.

Purpose: Since the neurotransmitter glutamate mediates nociceptive and pathological processes in arthritis, we have investigated how glutamate receptor and transporter expression varies with anatomical site or disease severity in subchondral bone of patients with osteoarthritis.

Methods and Results: Subchondral bone was sampled from tibial cuts derived from total knee arthroplasty (n=2, TKR, Kellgren Lawrence[KL] grade 3) and from tibial drill hole sites from high tibial osteotomy (n=2, HTO, KL grades 2 and 3) for osteoarthritis. RNA was extracted, reverse transcribed and RT-PCR performed for the housekeeping gene GAPDH, the glutamate transporter EAAT-1, and glutamate receptors (NR2A and KA1). Quantitative RT-PCR assessed differences in the expression of EAAT-1, a dominant negative splice variant called EAAT-1ex9skip and osteocalcin after normalisation to GAPDH.

Good quality RNA was obtained from bone cores removed from drill holes during HTO surgery, with GAPDH, EAAT-1, NR2A and KA1 expression detected. Osteocalcin expression was high indicating RNA was derived from osteoblasts and osteocytes, but did not vary with anatomical site or disease status. End-stage RT-PCR indicated differential expression of EAAT-1 between medial and lateral bone samples in total knee arthroplasty, however these differences were not significant by quantitative RT-PCR. In one patient, EAAT-1 expression was significantly reduced in the anterior zone versus the middle or posterior zones (ANOVA, p< 0.001). EAAT-1ex9skip represented a significant proportion of the total EAAT-1 mRNA expression in bone from TKR patients, but appeared less abundant in HTO samples.

Conclusion: We have shown for the first time that glutamate transporters and receptors are highly expressed in subchondral bone of patients with osteoarthritis and that EAAT-1 expression may vary with anatomical location and pathology. Activation of these receptors and transporters by the increased synovial fluid concentrations of glutamate that occur in arthritis may contribute to pathological changes and nociception.

Purpose of the study: Since the neurotransmitter glutamate mediates nociceptive and pathological processes in arthritis, we have investigated how glutamate receptor and transporter expression varies with anatomical site or disease severity in subchondral bone of patients with osteoarthritis.

Methods and results: Subchondral bone was sampled from tibial cuts derived from total knee arthroplasty (n=2, TKR, Kellgren Lawrence grade 3) and from tibial drill hole sites from high tibial osteotomy (n=2, HTO, KL grades 2 and 3) for osteoarthritis. RNA was extracted, reverse transcribed and RT-PCR performed for the housekeeping gene GAPDH, the glutamate transporter EAAT-1, and glutamate receptors (NR2A and KA1). Quantitative RT-PCR assessed differences in the expression of EAAT-1, a dominant negative splice variant called EAAT-1ex9skip and osteocalcin after nor-malisation to GAPDH.

Good quality RNA was obtained from bone cores removed from drill holes during HTO surgery, with GAPDH, EAAT-1, NR2A and KA1 expression detected. Osteocalcin expression was high indicating RNA was derived from osteoblasts and osteocytes, but did not vary with anatomical site or disease status. End-stage RT-PCR indicated differential expression of EAAT-1 between medial and lateral bone samples in total knee arthroplasty, however these differences were not significant by quantitative RT-PCR. In one patient, EAAT-1 expression was significantly reduced in the anterior zone versus the middle or posterior zones (ANOVA, p< 0.001). EAAT-1ex9skip represented a significant proportion of the total EAAT-1 mRNA expression in bone from TKR patients, but appeared less abundant in HTO samples.

Conclusion: We have shown for the first time that glutamate transporters and receptors are highly expressed in subchondral bone of patients with osteoarthritis and that EAAT-1 expression may vary with anatomical location and pathology. Activation of these receptors and transporters by the increased synovial fluid concentrations of glutamate that occur in arthritis may contribute to pathological changes and nociception.

Purpose of the study: Since glutamate can activate both nociceptive and pathological processes, we have investigated glutamate signalling in patients with painful and asymptomatic meniscal tears to determine which components are expressed, whether this varies in different anatomical regions of the meniscus and whether it is influenced by pain or degeneration.

Methods and results: Meniscus samples were obtained from two patients undergoing arthroscopic partial meniscal resection for chronic degenerate painful meniscal tears, from one patient with a torn painless meniscus and from the less affected compartment of the knee joint of three patients undergoing total knee arthroplasty. Menisci were dissected into anatomical regions (anterior horn, body, posterior horn, inner vascular, outer avascular), cryosectioned and RNA extracted. RNA was reverse transcribed and PCR performed for the housekeeping gene GAPDH and glutamate receptor subunits (NR2A, AMPA GluR3, KA1). Absolute quantitative RT-PCR assessed mRNA expression of glutamate transporters (EAAT-1, EAAT-1ex9skip) and type I collagen after normalisation to GAPDH or total RNA.

Human meniscus expressed GAPDH, type 1 collagen, EAAT-1, EAAT-1ex9skip, NR2A, AMPA GluR3 and KA1 mRNAs. Levels of EAAT-1 expression, normalised to GAPDH, did not differ between the inner and outer halves, or in the anterior, middle or posterior regions of menisci from the less affected compartments of arthritic knees. EAAT-1 expression appeared greater in the 2 painful, compared with the single non-painful meniscus. Interestingly, EAAT-1ex9skip was significantly more common within the outer zones (ANOVA, P=0.040) and in the posterior horns of the menisci (ANOVA, p=0.038).

Conclusion: We have shown for the first time that glutamate receptors and transporters are expressed in human meniscus providing a potential mechanism underlying the pathophysiology of pain associated with a torn meniscus. Our preliminary data indicate that EAAT-1 and EAAT-1ex9skip expression may vary with extent of damage and anatomical location in the human meniscus.

Traditional management of spinal metastases has been for the most part palliative. In this decade however there has been a gradual shift towards extirpative treatment of spinal secondary malignancy in certain circumstances. The techniques of en bloc vertebral resection have gained more widespread acceptance improving the chances of successful wide or marginal resection of both primary and secondary tumours of the spine. Those metastatic lesions which are solitary and associated with a long period of latency from treatment of the primary lesion have a greater likelihood of improved survival with en bloc resection. Although technically demanding, these same techniques coupled with advances in spinal implantation may allow complete excision of extended primary malignancy of the spine previously considered unresectable. This presentation examines the indications for en bloc resection of secondary and extended primary malignancy of the spine. A case for early referral of solitary metastatic spinal lesions is presented in the hope of adding extirpative surgical techniques to the traditional armamentarium of theoncologist.

Introduction: It is well known that the fate of biomaterials is determined by the distribution of proteins attached to the surface from the initial contact with blood or serum. This profile determines wether a material is inert, creates a foreign body response or is bioactive. Bioinert materials, such as polyethylene completely denature surface proteins, whilst materials inducing inflammatory responses are predisposed to complement protein attachment. Bioactive materials such autologous tissue grafts adsorb, but do not denature serum proteins such as fibronectin and Von Willebrand’s factor. This does not interfere with the healing cascade. This aim of this study is to prepare a synthetic bone graft substitute that activates the body’s autologous healing cascade by activating platelets, without activating a complement response through the controlled adsorption of serum proteins.

Methods: Polymers composed of varied concentration of acrylic acid (AA) and comonomers (methyl, ethyl and butyl methacrylates (MMA, EMA, BMA)) were prepared in glass vials by free radical polymerisation. Fresh blood was collected from a healthy donor and pipetted immediately into each chamber. Glass was used as a control. The chambers were incubated at 37o C for 2 hours. The surface morphology was examined using Scanning Electron Microscopy (SEM). Concentration of complement protein C5a and prothrombin fragments 1 and 2 were determined using commercial ELISA kits. Foreign body reaction (FBR) initiated by the biomaterial was estimated by counting leukocytes on clot sections using immunofluorescence.

Results: Extent of coagulation was correlated with plasma concentrations of Prothrombin fragments 1 and 2. These measurements show blood incubated with various polymers composed of different comonomers all promoted the formation of blood clots. It was found that the leukocyte population towards the interface of clot and polymer (AA:MMA) decreased with increasing surface acid concentration (65%AA:MMA 30 leukocytes/0.25mm2, glass 70 leukocytes/0.25mm2 (p< 0.05)). FBR is induced by the activation of complement system. The percentage of C5a concentration detected in blood incubated with various polymers composed of different comonomers relative to normal serum level of C5a (35ng/mL). No significant elevations of C5a were measured from polymer 65% AA:MMA and 65% AA:EMA. Glass induced vigorous complement response as expected. The synergistic combination of surface acid concentration and comonomers had a significant effect on extent of FBR. Increased acid concentration resulted in decreased C5a level with MMA and ET but increased level with BMA.

Discussion: The functional groups exposed on the surface of a material influence whether leukocyte or platelet activation is responsible for the subsequent physiological response. By modifying the combinations of surface acid concentrations and comonomers, we show that a biomaterial with an appropriate surface chemistry promotes the platelet plug formation and coagulation but down regulated foreign body reaction. This study shows that that a biomaterial with the appropriate surface chemistry to evoke the same coagulation response as damaged tissue, mediated through platelet activation and intrinsic and extrinsic coagulation, initiates the initial pathways of the bone healing cascade. This material is a realistic candidate for biomaterial induced bone regeneration.

Introduction: The biological activity of autologous grafts is due to a number of proteins (growth factors) that control bone cell differentiation, proliferation and expression. Several of these have been isolated including; bone morphogenetic proteins 2 and 7. These are commercially available and regularly used with the intention of accelerating fracture healing, repairing critical sized defects and combating bone mineral loss. Whilst it is commonly recognised that multiple growth factors are present at differing times in the healing cascade, the usual delivery, both in the clinic and the laboratory, is of one growth factor delivered over a very short and early time period. Commonly growth factors are delivered in solution or from a collagen sponge and are quickly metabolised in the proteolytic wound healing environment. The physiological need for BMPs is later than the acute delivery at the time of surgery. The aim of this study is to develop a granular protein delivery system that enables controlled release of multiple proteins at a variety of time points.

Methods: A series of homogenous polymer granules 8mm3 were prepared by photo-polymerising 12uL of mixtures of methacrylated adipic acid anhydride (MAAA) and methyl methacrylate (MMA) or MAAA and butyl methacrylate (BMA) with molar ratios ranging from 100- 55 % (MSAA). Into each granule 5ug of a model drug, carmoisine was loaded and 1%w/w of 2,2-dimethoxy-2-phenyl-acetophenone (DMPA) photoinitiator was added per granule. The granules were exposed to UV light at 390nm for 14 minutes. Multilayered granules were prepared photo-polymerising 4uL layers of different monomer compositions in a similar method to the single layered method above. The composition of the multilayered granules was chosen to optimise the release profile. Carmoisine release profiles were determined by UV-visible spectroscopy.

Results: Homogenous granules composed of 100% MAAA released 90% of their payload by 24hrs, those composed of 90:10 MAAA:MMA released by 48hrs those composed of 70:30 MAAA:MMA released by 80hrs those composed of 60:40 MAAA:MMA released by 170hrs those composed of 70:30 MAAA: BMA released by 288hrs and those composed of 60:40 MAAA:BMA released by 456hrs. The multilayered granule had a sustained release of the model drug over the test period of 19 days.

Discussion: The limitation of most drug delivery systems, such as microspheres or collagen, is poor control over the release profile. The drug is ether released instantly or well after it is required. This multilayered composite drug delivery system enables the controlled release of different bioactive compounds at different time points between 0 and 19 days. By altering the drug loading in each layer we were able to sustain the release of one compound over this time period. This technology enables us to switch compounds at a given time points for example delivery of angiogenic factors for one week, proliferative factors for the second week and differentiation factors for the third week. This technology enables the pre-programmed release of multiple growth factors at times in the healing cascade when they meet the physiological need. A controlled release of growth factors at the appropriate time should improve bone healing rates.

Introduction: Acute neurological damage from spinal cord injuries is believed to be localised, however it initiates a cascade of secondary events which usually leads to extensive and permanent neurological deficit. The secondary damage begins with the disruption of the blood-spinal cord barrier which unleashes a protracted inflammatory response. This prolonged inflammatory response is the catalyst for the secondary neurodegeneration and limited repair response that occurs in the chronic phase of a spinal cord injury. In this study it was proposed that the acute delivery of the angiogenic growth factors vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF) would mediate inflammation and restore the blood spinal cord barrier. This would minimise the formation of glial scar and reduce the extent of secondary degeneration caudal and cranial to the lesion site.

Methods: Adult male Wistar rats (400g) were anesthetised. Complete laminectomies were performed at T10 and the animals were subjected to T10 hemisection. Animals were randomised to a treatment group (Lesion Control (LC), Gel Control (GC) and Angiogenic Gel (AG)) after the spinal cord was cut. Each treatment group had 6 animals sacrificed 3 months post injury. Sections were stained with antibodies to neurofilament 200, glial fibrillary acidic protein, smooth muscle actin (SMA), and fluorescent secondary antibodies and mounted with DAPI. The lesion size was measured from horizontal histological sections of the midline from 5 animals in each group using Axiovision version 4.6.1.0 (Carl Zeiss Imaging Solutions, Germany).

Results: The mean lesion size for the lesion control group was 2.09mm2, 1.97mm2 for the gel control group and 0.45mm2 for the active gel group. A t-test was used to confirm that the differences between the active gel and the two control groups were statistically significant (AG vs LC p= 0.021 AG vs GC p= 0.026). Histology showed a marked improvement of the morphology of the astrocytes in the treatment group over the control groups indicating that the treatment affected the population of reactive astrocytes. SMA staining showed an increased level of revascularisation in the treated lesions.

Discussion: Spinal cords do not heal because of prolonged inflammation which leads to secondary necrotic events, scar formation and the inhibition of regeneration. In this study we present a method for regulating the post lesion inflammatory signals, significantly reducing post-lesion scar formation. We propose the delivery of VEGF/PDGF significantly increases the permeability of the blood spinal cord barrier to neutrophils and macrophages and promotes angiogenesis observed in the lesion site. This may have two major effects on the progression of the spinal cord injury. Firstly, by increasing the initial influx of inflammatory cells it enables the faster removal of damaged tissue and phagocytosis of apoptotic cells thereby restoring the balance in favour of regulated inflammation and results in a finite and reduced inflammation time. Secondly, combination of VEGF and PDGF provides a robust angiogenic response and reduces ischemia, the population of reactive astrocytes and the capacity to form glial scars. These growth factors appear to moderate the secondary degenerative changes that result from the prolonged inflammation and thus promote the inherent capacity for regeneration.

Introduction: It has long been recognised that static plain x-rays are a sub-optimal method for the assessment of lumbar fusion. Blumenthal and Gil showed that radiographic assessment of fusion corresponded with operative findings only 69% of the time. Santos et al suggest that both plain x-rays and flexion/extension x-rays overestimate the fusion rate when compared to helical computed tomography (CT). To date there has been no correlation of CT assessment of fusion with surgical exploration. In this study we present an animal model of lumbar spine pseudarthrosis and compare three imaging modalities with micro-cut CT scanning and cadaveric assessment.

Methods: Approval was gained from the QUT animal ethics committee. Eleven mixed bred ewes were assigned to either a fusion group or an intentional pseudarthrosis (IP) group. A dorsal approach to the facet joints of L2/3 was made. The facet joints were destabilised by resecting the articulating surfaces with a rongeur. In the fusion group, the spinous processes of the destabilised segment were wired tightly together and a bone graft harvested from the iliac crest was placed into the joint space. In the IP group the bone graft bed was prepared similarly except that a small proportion of the articulating surface was left intact and a 1.0 cm2 roll of oxidised cellulose was placed into the facet joint space bilaterally. In the IP group the spinous processes were wired around an interspinous spacer which was later removed to create a similar degree of laxity in the fixation of each of the IP specimens. The animals were sacrificed at 6 months and static and dynamic lateral radiographs obtained. The spine was removed en bloc, and high speed fine cut (2mm) CT Scanning performed. The specimens were individually assessed for fusion by micro-cut CT scanning. Eight independent, blinded orthopaedic surgeons, were asked whether they considered the spine to be fused based on

plain x-ray

These results were correlated with a fusion rate based on the micro CT. The specificity and sensitivity of these radiological measures in diagnosing pseudarthrosis and inter-rater reliability using Fleiss’ Kappa scores for each method were calculated.

Results: For assessing pseudarthrosis identified by microCT the plain film sensitivity was 0.41 and the specificity was 0.47. For assessing pseudarthrosis with plain and flexion extension xrays the sensitivity was 0.55 and the specificity was 0.33. For assessing pseudarthrosis with plain flexion extension xrays and CT the sensitivity was 0.81 and the specificity was 0.88. The Kappa score for plain films was 0.15, for flexion extension was 0.07 and CT was 0.54.

Discussion: This study suggests that plain radiographs and flexion extension radiographs are an unreliable measure of posterior lumbar fusion. The current clinical gold standard for assessment of fusion (CT) was able to correctly identify non-union in 80% of cases. Whilst no alternatives to structural assessment of the fusion mass with CT currently exist it is important to recognise the limitations of this technique.

Purposes of the study: Anterior cruciate ligament (ACL) deficiency is associated with degenerative osteoarthritis especially when it is present with meniscal injury; We assessed the impact of certain aetiological factors in chondral degeneration in the ACL deficient knee.

Methodology and Results: Fifty-eight patients who underwent consecutive primary arthroscopic anterior cruciate ligament reconstruction using the four strand hamstring graft between 10/06/2004 and 29/06/2006 were retrospectively analysed.

Patient’s charts and radiology findings were reviewed with special attention to operative notes and preoperative knee MR imaging. Patients with knee symptoms prior to presenting injury were excluded.

The mechanism of injury, the time elapsed from the original injury to anterior cruciate ligament reconstruction, associated meniscal injury, and quality of cartilage in the knee- at the time of MR imaging and ACL reconstruction were noted. Degenerative cartilage changes were graded upon reconstruction using the Outerbridge classification.

The average time from Injury to MR imaging and MR to ACL reconstruction was 4.85 and 12.65 months respectively.

We found a direct relationship between the time elapsed after the ACL injury and the severity of the chondral lesion (p< 0.05). Furthermore, a significant worsening in chondral degeneration of the involved knee was seen when the MR imaging and ACL reconstruction were more than 12 months apart (p< 0.01).

Conclusion: We conclude that chondral lesions and degeneration are more likely to be caused by an extended period of knee instability following ACL injury as opposed to age related degeneration or direct trauma to the weight bearing area of the knee.

Early reconstruction may protect the knee from chondral wear and subsequent degenerative arthritis.

Introduction- Proximal humeral fractures remain a challenging problem. Most authors agree that anatomical reduction and stable fixation are essential to allow early range of motion. A variety of techniques have been described such as threaded pins, tension band wiring, screws, nails, plates and primary prosthesis. Locking plates score over other implants by the virtue of providing greater angular stability and better biomechanical properties. The Aim of the Study is to evaluate the functional outcome of PHILOS plate Osteosynthesis of displaced proximal humeral fractures.

Materials and Methods- A retrospective study of 50 patients treated with PHILOS plating for the 2 part, 3part and 4 part proximal humeral fractures with a minimum follow up of 1 year. All the patients were assessed in clinic by Constant Murley and ASES scoring systems. X-ray evaluation was done for fracture healing, AVN, mal-union, non-union, collapse of head, screw penetration and impingement of plate.

Results- Total of 50 acute displaced fractures of proximal humerus treated with PHILOS plating between 2003–2005 were assessed. Mean age was 64 years (15–86) Male to female ratio was 12:38, dominant to non-dominant ratio was 32:18. According to Neer’s classification 16 fractures were 2 part, 24 fractures were 3 part and 10fractures were 4 part. The overall mean Constant score was 73.4(range20–100) and ASES score was 71.7(range 25–98). Under 60 years of age the mean Constant and ASES scores were 83.5 and 83, over 60 years of age scores were 63.1 and 60.4 respectively. The complications include two deep infections which needed excision arthroplasty, one malunion, one subacromial impingement which needed plate removal after fracture healing. No mechanical failure, no non-union, no ANV was noted.

Conclusions- PHILOS plate Osteosynthesis is a reliable method of treating complex proximal humeral fractures. It provides good mechanical stability and allows rapid mobilization with out compromising fracture healing.

Introduction: Various techniques are being currently used for the internal fixation of scarf osteotomies. We conducted a prospective study on 23 consecutive cases of hallux valgus treated with scarf osteotomy, which was internally fixed with AO mini fragment screws. The aim of our study was to evaluate the clinical efficacy of the AO mini fragment screws in these cases.

Method: Sixteen women and one man (twenty three feet) were included in our study. Mean age was 46 years at the time of surgery. The mean follow-up time was 18 months. A single surgeon performed surgery. Patients were assessed by clinical and radiological evaluation. Preoperative and postoperative American Orthopaedic Foot and Ankle Society score was obtained.

Results: All the osteotomies united without any failure of fixation or hard ware problems. One patient developed superficial wound infection, which responded to antibiotics. At the time of follow-up all the patients were very satisfied. The mean AOFAS score improved significantly from 55 points pre-operatively to 91.95 at follow-up (p < 0.001). The intermetatarsal and hallux valgus angles improved from the mean pre-operative values of 15.86° and 31.18 degrees to 9.09° and 15.18°, respectively. These improvements were significant (p < 0.0001).

Conclusion: We report no failure of fixation in our series and conclude that this is a safe and simple technique. It is cost effective, provides stable fixation and maintains correction till the union of osteotomy.

Introduction The precise contribution of the posterior longitudinal ligament (PLL) and disc annulus in the burst fracture setting and their potential relative roles during intra operative reduction manoeuvres remains unclear. The anatomical attachments of the posterosuperior fragment most often associated with canal occlusion and potential neurological compromise are not well described in a reproducible model.

Methods Burst fractures were induced using a pendulum impact tester. The jig allowed for accurate positioning in all planes and for precise delivery of both the magnitude and vector of the impact force. This allowed for creation of fracture all three major groups of the AO classification. The A3 (burst fracture) was produced in 10 cadaveric sheep spines by delivering a neutral force vector on a physiologically flexed spine. The morphology of the fracture was confirmed by CT. Subsequent laminectomy was performed and the anatomical attachments of the large fragments were identified.

Results The PLL was identified following laminectomy in each case. In six of the ten spines there had been significant disruption of the longitudinal structure of the PLL .In a further two cases there had been stripping of the PLL from the posterior aspect of the vertebral body in association with the retropulsed canal fragment. Subsequent excision of the PLL from the posterior aspects of vertebral body and discs did not compromise the attachment of the retropulsed fragment to the disc annulus in any case.

Discussion This study confirms the anatomical relationship between disc fragment and disc annulus in the burst fracture setting. The strong attachment between fragment and disc facilitate rotation of the fragment about this hinge and into the canal. Subsequent intraoperative reduction of this fragment by restoration of disc height may require contribution both from this annular attachment and from tension set up in an intact PLL. The relative contributions of each of these structures in the reduction manoeuvre remains unclear.

Introduction A tertiary referral centre for spinal injuries will receive referrals from many different centres. The format and quality of imaging that accompanies these patients varies considerably.

Methods Two cases are reported where initial imaging demonstrated unstable cervical spine injuries that were subsequently found to be normal. The cases and images are presented.

Results A 19-year old female was transferred to our unit having fallen off a wall and sustaining a neck injury. The accompanying CT scan showed a C6 vertebral body fracture with bilateral fracture-subluxations of the facet joints. As there was a discrepancy with the clinical findings, a repeat fine cut CT scan was performed which was completely normal. The previous appearances were entirely due to artifact throughout the scan.

A 46-year old male fell down stairs sustaining a neck injury and loss of consciousness. A CT scan of his cervical spine demonstrated an odontoid peg fracture (type II). Subsequent imaging showed the odontoid peg was completely normal. The initial CT appearances were entirely due to artifact caused by the patients’ tongue piercing!

Discussion CT scans are used with increasing frequency in the assessment of cervical spine injuries. In both these case the abnormalities present on the initial scans were entirely due to artifact that was reciprocated through the entire CT scans. Reporting these cases reinforces the importance of careful clinical examination and correlation with appropriate investigations. If there is a discrepancy between the clinical and radiological findings then it is essential that further imaging is performed.

Introduction Far lateral disc prolapse (also known as foraminal or extreme lateral prolapse) make up 10% of all disc herniations. In addition, far lateral disc prolapses tend to affect more proximal levels more frequently than do prolapses in the posterolateral location and they are often associated with greater radicular symptoms than typical posterolateral herniations, most likely due to involvement of the dorsal root ganglion. Surgery for far lateral disc protrusions has been associated with a less favourable outcome, perhaps due to delays in diagnosis, inadequate preoperative imaging, and postoperative instability as a result of excessive bony and facet resection during the surgical approach

Methods Twelve patients with far lateral disc herniations operated on by the senior author (RPW) fulfilled the criteria of having both pre- and postoperative Oswestry Disability Index (ODI) scores recorded at each clinic visit. Results of these cases and those of a cohort of age and sex matched patients undergoing standard posterolateral discectomy undertaken by the same surgeon were analyzed. The presence of radiculopathy pre- and postoperatively, workers compensation status, return to work, length of stay and complications, as well as any prior intervention in the form of nerve root sleeve blocks or surgery were recorded

Results Both groups were well matched in terms of age and sex. Follow up ranged from 4 to 18 months. Herniations at more proximal levels (L2/3 and L3/4) were seen more frequently in the far lateral group than in the posterolateral group. Six patients in the far lateral group had preoperative nerve root sleeve blocks compared with one in the posterolateral group. Two patients in each group had had previous (different level) surgery. Patients in each group had similar preoperative ODI scores. Both groups demonstrated a reduction in the preoperative ODI compared with the preoperative score. The mean improvement was 24 (range −26 to +62) for the far lateral group and 22 (range −6 to +46). There was no significant difference between the groups

Discussion The results of this study are encouraging with respect to surgical treatment of far lateral discs. Recent literature has questioned the efficacy of surgical intervention for this pathology. These results show that with carefully selected patients results are comparable with standard posterolateral discectomy

Introduction Reported clinical results suggest that vertebroplasty is a safe and effective technique for providing pain relief. However, information about the long-term effect of PMMA on the adjacent intervertebral discs and the augmented bone is lacking. Adjacent intervertebral discs may be at higher risk of degeneration due to nutritional constraints. Bone loss in augmented vertebrae may occur due to mechanical stress-shielding or toxicological effects.

The aim of the present study was therefore to investigate the effect of PMMA augmentation on intervertebral disc and bone tissue after 6 and 12 months, using an animal model.

Methods In 12 skeletally mature sheep, 2.0ml PMMA (Simplex P) was injected into three lumbar vertebrae (approved by Animal Ethics Committee). Two injection holes were drilled into the middle of three vertebrae at a distance of 5.0mm from the cranial and caudal endplate and 1.0ml PMMA was injected into each hole. Four weeks before euthanasia, animals received an injection of tetracycline for bone labeling.

Postmortem, T1- and T2-weighted sagittal and axial MR images were taken prior to fixation in 80% ethanol. Spines were cut into specimens containing one intervertebral disc and half of the two adjacent vertebrae. The discs which were two levels above the first augmented vertebra served as controls. Microsections were stained with H& E, Goldner, Alcian blue-PAS and Safranin O. MRI signal intensity and morphology of discs were evaluated qualitatively. Histomorphological analysis of discs and endplates was conducted using published criteria [1]. Presence of bone remodeling, fibrous tissue and foreign body reaction in the vertebrae was also recorded.

Results There was no distinguishable loss of MRI signal intensity in the discs in between augmented vertebrae. Cement injection resulted in blocking 50–75% of the endplate lengths. Most discs that were in between augmented vertebrae showed signs of degeneration (chondrocyte proliferation, necrosis) after 6 (80%) and 12 months (88%). Inflammatory reaction to PMMA was observed in some specimens (approximately 25%). Cement had been covered with fibrous tissue in all augmented vertebrae, but tetracycline labeling revealed new bone formation in the vicinity of PMMA.

Discussion Augmentation of three adjacent vertebrae initiated degenerative changes of intervertebral discs in between two augmented vertebrae. This is in contrast to previous animal studies [2] where no degenerative changes after cementing endplates were observed. Current investigations were performed with the specific aim to block the endplates. Clinically, endplates may not get blocked as effectively. On the other hand, discs in older patients are nutritionally constrained due to end-plate calcification and even partial blockage may lead to degenerative changes as documented presently.

The risk of degenerative changes of intervertebral discs should be considered in patients undergoing vertebroplasty.

Introduction: Mazabraud syndrome is a rare disorder characterised by fibrous dysplasia and intramuscular myxomas. We present six new cases.

Method: A reterospective review was performed on six patients from our institution. This is a consecutive series over 48 months.

Results: The patient group consisted of three females and three males. The six patients were referred to our bone tumour unit from other hospitals (four by orthopaedic teams and two by general surgeons). The referring hospitals had been unable to exclude a malignant process. Imaging was tailored to each individual case. Three of our six patients demonstrated polyostotic fibrous dysplasia. The commonest site of the osseous leision was the proximal femur (n=4). The majority of the patients had solitary myxomas (n=4) with only two being multiple myxomas. The average size of the myxomas was 3.7 cm. All soft tissue leisions were ipsilateral to the osseous leisions.

Five of the six patients were treated with surgical excision.

Discussion: In contrast to the existing literature the majority(n=4) of the six patients had solitary myxomas and the male to female distribution was equal. One of the cases was also unique to the current literature with the syndrome present in the right elbow.

The number of cases that we have seen in a short time may also be an indication that this syndrome is not as rare as scarcity of the published cases would imply.

We propose a grading system for contrast free MRI images of tennis elbow and evaluate the inter and intra observer variability of their interpretation.

Methods: Three senior orthopaedic surgeons were asked to blindly grade 0.2T dedicated extremity contrast free MRI images of elbows of patients who presented with varying degrees of symptomatic tennis elbow.

Our proposed grading system of 1 to 5 based on the pattern around the common extensor tendon was used.

Images of the symptomatic and contralateral non symptomatic elbows were graded blindly twice with an interval of 1 month by each surgeon.

Each surgeon graded 176 MRI images twice.

The grades were subsequently grouped into (I) grades 1 to 2 and (II) grades 3 to 5

Results: With regards to the intra observer agreement, consultant A showed 90.1% agreement, consultant B showed 90.6% agreement and consultant C 96.0% agreement. The mean intra observer agreement rate was 92.2%.

The inter observer agreement between consultant A and B was 82.46%, between A and C 67.1% and between B and C 80.1%.

It was also noted that there were systematic differences to the inter observer variability. Consultant A graded the images 3 to 5 on both occasions 52.9% of the time, consultant B graded 3 to 5 on both occasions 37.8% of the time and consultant C graded 3 to 5 on both occasions 23.3% of the time.

Conclusion: The intra observer agreement rate is high. There is however a greater inter observer variation but this variation is consistent. We suggest that the inter observer differences can be improved by (1) reducing the grades to positive or negative and (2) by group reeducation of the observers.

Introduction Charcot arthropathy is a well recognised complication in denervated synovial joints. This is a late complication of traumatic spinal cord injury that is rarely reported in the literature. Early recognition is important and can be difficult as the clinical presentation can vary from pain, deformity, autonomic dysreflexia and audible noises with motion.

Methods We present 5 cases of Charcot’s arthropathy of the spine in patients with in patients with traumatic paraplegia. All patients had spinal surgery to stabilise the spine shortly after the acute injury.

Results The average time from initial injury to presentation with Charcot’s arthropathy was 27 years (range 10–41). A combination of localised and neuropathic pain was the dominant symptom (4 patients) causing re-presentation, but other symptoms included deformity (1 patient). The level of the initial spinal cord injury was at the thoracolumbar junction patients. The Charcot joint level was usually 1 to 2 segments caudal to the spinal fusion. The features noted on plain radiology were destructive changes of the endplate in 4 patients and deformity in 1. With one exception, all patients went on to have MRI to exclude infection and subsequently all were surgically stabilised. All patients were treated surgically. One had an anterior approach, one had posterior approach and one had staged anterior and posterior approaches. The remaining two had anterior and posterior stabilisation through a lateral extra-cavitary approach.

At an average follow-up of 36 months all patients reported good relief of their symptoms, and had returned to their best function post-injury.

Discussion Surgical stabilisation in this series yielded very good results. We observed a wide variation in presenting symptoms and therefore would indicate that a high index of suspicion is required. We believe that MRI is mandatory to exclude infection and would advocate early stabilisation. The lateral extra-cavitary approach allows posterior and anterior stabilisation in a single procedure and in now the preferred method in our institution. As patients with spinal cord injuries live increasingly active lives, this problem will be seen more frequently.

Tibiotalocalcaneal (TTC) fusion is indicated in rheumatoid patients with combined ankle and subtalar disease, particularly when severe deformity is present. In theory, if bone stock is good, a staged subtalar/triple arthrodesis followed by total ankle replacement (TAR) can be used. This is so rarely the case that the author has no experience of this. TTC fusion is also useful in rheumatoid patients with previous joint sepsis, to salvage a failed TAR and to salvage a non-united ankle fusion. It allows early weight bearing, which is valuable in those patients who have multiple joint, particularly upper limb, involvement.

In our study, 18 patients underwent 21 TTC fusions from August 1988 to September 2002. The average age was 48 years (range 23–90). Nine patients had undergone previous hindfoot procedures, five were smokers, one was diabetic and one had chronic renal failure. Surgery was performed under GA with tourniquet. Patients were reviewed using a modified American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score and with regard to their personal satisfaction. Follow up was 18–57 months.

Post-operatively, the oldest patient died due to fulminant sepsis. Seven patients had superficial wound infections but none required re-operation. Fusion was achieved in 18 limbs. Average time to radiological union was 36 weeks (range 9–68), two patients required nail dynamisation. In six cases it was necessary to remove irritating locking screws, either the posterior screw for heel rubbing, or the medial tibial screws for stress riser symptoms. One patient required complete nail removal. There were no amputations.

Fourteen patients were very satisfied, two reasonably so and one not. The average AOFAS pain score (max 40) improved from 11 to 32, and the average AOFAS functional score (max 28) from 4 to 21.

We feel that despite the relatively high complication rate, this technically challenging procedure is a very useful salvage option in these very disabled patients.

Introduction Experimental heterotopic bone formation in the canine urinary bladder has been observed for more than seventy years without revealing the origin of the osteoinductive signals. In 1931, Huggins demonstrated bone formation in a fascial transplant to the urinary bladder. Through an elaborate set of experiments, it was found that proliferating canine transitional epithelial cells from the urinary system act as a source of osteoinduction.

Urist performed a similar series of experiments in guinea pigs as Huggins did in his canine model. After two weeks, mesenchymal cells condensed against the columnar epithelium and membranous bone with haversian systems and marrow began to form juxtapose the basement membrane. At no time was cartilage formation noted, only direct membranous bone formation. They also demonstrated the expression of BMP’s in migrating epithelium and suggested that BMP is the osteoinductive factor in heterotopic bone formation.

Method This study was approved by Institutional Animal Ethics Committee. Six dogs underwent a mid-line laparotomy incision followed by mobilisation of a right sided myoperitioneal vascularised flap based on an inferior epigastric artery pedicle. A sagittal cystotomy is made in the dome of the bladder and the vascularised flap was sutured in place with acryl absorbable, continuous suture. The animals were sacrificed at 6 weeks. The bladder samples were removed and assessed by histology and immunohistochemistry. Sections were incubated with optimal dilution of primary antibody for type I collagen, type III collagen, alkaline phosphatase (ALP), bone morphogenetic protein (BMP)-2 and –4, osteocalcin (OCN), osteopontin (OPN), bone sialoprotein (BSP).

Results The mechanism for bone formation induced by the epithelial-mesenchymal cell interactions is not clear. We were able to demonstrate mature lamellar bone formation 6 weeks after transplanting a portion of the abdominal smooth muscle into the bladder wall. The bone formed immediately adjacent to the proliferating transitional uroepithelium, a prerequisite for bone formation in Huggins’ model. Here we report evidence of cartilage formation and therefore endochondral ossification as well as membranous bone formation. This is very similar histologically to the process of endochondral ossification at the growth plate in the growing skeleton. We propose a mechanism for the expression of BMP by epithelial cells.

Discussion This study demonstrates transitional epithelium induced formation of chondrocytes and osteoblasts in muscle tissue. The sequential expression of bone matrix proteins was related to cell proliferation, differentiation and formation of endochondral and membranous bone. Further information regarding the molecular mechanism of bone formation induced by epithelial-mesenchymal cell interactions will improve understanding of cell differentiation during osteogenesis.

Introduction The influence of timing of surgery on functional outcomes following spinal cord injury remains controversial. Animal studies suggest that the rate, degree, and duration of cord compression are the principal determinants of spinal cord injury (SCI) severity and prognosis for recovery. Delamarter et al, (J Bone Joint Surg Am 1995) have shown that when experimental cord compression in dogs is relieved within 1 hour, full motor recovery can be achieved. It is suggested by some clinically based research that definitive surgical treatment for unstable injuries results in fewer sequelae than prolonged immobilization and allows more rapid entry into rehabilitation. It is however the timing of this surgery which remains controversial. It has been suggested that early surgical management promotes neurological recovery by limiting secondary damage caused by inflammation, oedema, ischemia and instability. To date few studies have found a link between neurological recovery and timing of surgery (Fehlings, et al; Spine 2001).

Methods Data was gathered retrospectively by chart review of patients referred to the Princess Alexandra hospital with spinal cord injury. Patients were age matched into high and low velocity groups. This data was studied to assess the effects of energy of injury and timing of surgical intervention on neurological outcome. Patients either had anterior, posterior, or combined surgery, external immobilization or traction depending on the preference of the treating surgeon.

Results A cohort of 43 patients all of whom had spinal cord injury was retrospectively studied. Of these, 21 had a high energy injury (eg. MVA) and 21 had a low energy injury (eg. rugby). 28 had anterior stabilization 7 had traction, 4 had external immobilization 2 had a combined anterior / posterior fixation and 1 had posterior stabilization. The data suggest that the prognosis for recovery following a spinal cord injury is unrelated to the energy involved. The low energy group improved on average 0.6 ASIA grades (SEM 0.16) while the high energy improved 0.7 ASIA grades (SEM 0.17). The timing of definitive intervention for patients with incomplete cord lesions was shown to significantly (p=0.029) effect ultimate functional outcomes. Those with early (within 8hrs) intervention improved an average of 1.4 ASIA grades (SEM 0.21) and those with late intervention improved 0.6 ASIA grades (SEM 0.19). This effect was present in both high and low energy injury groups.

Discussion The timing of definitive intervention for spinal cord injury is still controversial. However there is Class II evidence that early surgery can be done safely in a patient with spinal cord injury (Fehlings, et al; Spine 2001). The findings from this retrospective study suggest that early surgical intervention may improve neurological recovery.

Introduction The purpose of this prospective controlled study was to define indications and analyse the clinical and radiographic results of cages in the surgical treatment of traumatic cervical spine instability.

Methods 53 patients were treated by monosegmental anterior discectomy and interbody fusion using either autologous tricortical iliac crest bone graft and cervical spine locking plate (CSLP) (bone graft group, n= 26) or Syncage-C (Synthes) filled with autologous cancellous bone grafts and CSLP (cage group n=27). Indications for surgery were traumatic cervical spine instability were classified by the cervical fracture classification of Blauth et al¹ as B1, B2, B3, C2 or C3 fractures. Intraoperative parameters (operative time, blood loss radiation time and intra- and perioperative complications) were documented. Prior to surgery and at follow-up (6 and 12 months) evaluation included measurement of neck pain, shoulder/arm pain and Neck Pain Disability Index (NPDI). Neurological function was assessed using the ASIA scale. Radiographic evaluation included plain X-rays, flexion-extension views and CT-scans. Patient satisfaction was measured on a five-point Likert scale.

Results There was no statistically significant difference between the two groups in the demographic data. One patient in the bone graft group was not available for the 1-year follow-up evaluation; however, all patients were available for the 2-year follow-up. Operation time was significantly shorter (p< 0.05) in the cage group (67 +/− 6 min) than in the bone graft group (78 +/− 9 min). After 6 and 12 months there was no difference between both groups in pain or NPDI, neurological and overall outcome. The neurological improvement of the two groups was not statistically different. Although the cage group showed a trend for better maintenance of lordosis after 12 months, there was no statistically significant difference between groups in all radiographic parameters. There were no implant-related complications during the follow-up. General complications included one patient with eczema due to the stiff collar (cage group) and one patient with pneumonia (cage group). Complications associated with the harvesting of iliac crest bone grafts included 14 patients (9 patients in the bone graft group, 5 patients in the cage group) with prolonged pain (> 3 months) at the donor site, one superficial wound healing problem (bone graft group) which healed under conservative treatment and one hematoma (bone graft group) which required additional surgery.

Discussion Cages offer a valid alternative to a tricortical iliac crest bone graft in the surgical treatment of mono-segmental traumatic cervical spine instability. Although there was no significant difference between the cage and the bone graft group in the functional and radiographic outcome, less donor site morbidity and a shorter operation time make cages cost effective in this selected group of patients. Although the cages are expensive, less donor site morbidity, shorter operation time and reduced hospital stay might result in cost-effectiveness of this implant.

Traditionally midshaft clavicle fractures have been treated conservatively. It is recognized that displaced and shortened fractures may be better treated operatively. In particular, patients with greater than 20 mm of shortening and 100 percent displacement have a symptomatic non union rate of 30 percent. The standard technique used previously has been via plate fixation with LC-DCP or DCP. However in the last 5 years intramedullary fixation has been popularized. “Rockwood intramedulary clavicular pin” remedies the past treatment issues including poor blood supply, painful prominent hardware and stress raiser related to removal of metal work.

Aim: The aim of this study was to assess the functional outcome following intramedullary fixation of clavicle using Rockwood pin.

Method: We retrospectively evaluated 17 patients with displaced and shortened mid-shaft clavicular fractures who underwent intramedullary pinning using Rock-wood pins. Each patient was assessed using the ASES, Constant and SF36 scoring system. A physical examination was performed and individual radiographs were assessed to determine union.

Results: The mean age of the patients was 28 (range 15–56). All patients went into union within 2 to 4 months. They had a shorter stay in hospital, earlier mobilization and no scar related paraesthesia. The average ASES score 98.2 (range 92–100) and constant 95.3 (range 89–100).

Summary: Displaced and shortened mid clavicular fractures require operative fixation. Plates and screws on the clavicle requires significant soft tissue stripping leading to compromised blood supply to the bone and multiple bi-cortical screws act as stress raisers. Previous intra-medullary devices presented with the problem of pin migration. Rockwood pins are designed with a differential pitch which leads to compression at the fracture site and prevent pin migration. From this study we now recommend the use of the Rockwood Pin for the management of displaced mid-shaft clavicle fractures.

Aim: To assess the functional outcome following internal fixation with the PHILOS® plating system for displaced proximal humeral fractures by using the ASES and Constant scoring system.

Background: Controversy exists with regards to the management of displaced proximal humeral fractures and many methods of treatment have been proposed over the years. In particular, the role of surgery has not been clearly defined. The current trend is toward limited dissection of the soft tissues with the use of minimal amounts of hardware to gain stability.

Methods: We performed a retrospective analysis of 30 consecutive patients treated surgically with the PHILOS ® plate for a displaced proximal humeral fracture between February 2002 and October 2003. Patients were assessed clinically and radio graphically at an average follow-up time of 9 months. Functional outcome was determined utilising the American Shoulder and Elbow Society score (ASES) and Constant Murley score. The injury was classified using Neer’s 4 part classification.

Results: Average age of the patients was 58 years (19 to 92). There were 6 two part, 14 three part and 10 four part fractures. All the fractures were radio graphically united by 10 weeks. The average overall ASES score is 66.5%. The average overall Constant score is 55%. The average external rotation at 90 of abduction for the ages 15–55 was 55°–64° and the ages 56–95 was 25°–34°. The average forward elevation for the ages 15–55 was 85°–95° and the ages 76–95 was 55°–64°. The most difficult movement for the older subgroup of patients was internal rotation which was up to the sacrum.

Conclusion: Our results show that good fracture stability and functional outcome can be obtained from the use of the PHILOS® plate. Early mobilisation of the shoulder can be achieved without compromising fracture union. We would recommend the use of the PHILOS® plate for the management of displaced fractures of the proximal humerus.

This preliminary report demonstrates the effective use of Apapore in the management of benign cystic bone lesions.

The use and development of bone graft substitutes over the past ten years has increased dramatically to improve their osseo-integration to a level similar to autografting techniques without the drawbacks of comorbidity from the graft site.

Apapore is a synthetic bone graft substitute which consists of a scaffold of synthetic phase-pure hydroxy apatite with micro- and macroporosity and inter-connectivity to favour bone repair.

Nineteen patients (12M:7F) with a mean age of 18.6years (8–33 years) having had procedures for the management of benign cystic lesions of bone with grafting using Apapore were followed up retrospectively for a mean period of 8 months (1–16months). In each case the diagnosis of a benign cystic lesion was made histologically prior to surgery. The subsequent definitive procedure was performed by a consultant on the Bone Tumour Unit at the Royal National Orthopaedic Hospital (Stanmore) in each case involving curettage and impaction of Apapore into the cavity in a standard fashion as a general anaesthetic procedure in the operating theatre.

There have been no complications to date. All patients have made uneventful recoveries. Short-term radiological follow-up demonstrates excellent incorporation of the bone graft substitute and osseo-integration.

When managing malignant bone tumours in the distal femur with limb salvage, resection and reconstruction with a distal femoral replacement (DFR) conventionally entails prosthetic replacement of the knee joint. In younger patients it is desirable to try to preserve the knee joint. We now use a new Joint-Sparing distal femoral prosthesis in those cases where it is possible to resect the tumour and preserve the femoral condyles. Purpose of study: To look at our early results with knee joint preserving DFR’s. Methods: Between June 2001 and March 2004 the prosthesis was implanted in 8 patients (5 males and 3 females) aged between 8 and 24 years at the time of surgery. The diagnosis was osteosarcoma in 6 cases and chondrosarcoma in 2 cases. All patients were followed regularly and knee range of movement was recorded as well as any complications that occurred. Patients were functionally evaluated using the MSTS Scoring System. Results: Six of the patients had a mean follow-up of 20 months (range 8–33) and in this group 4 had good knee flexion with a mean flexion of 122° (110–130), 1 patient had fair flexion of 60° and 1 patient had poor flexion of 20°. The mean fixed flexion deformity in the 3 patients who had such a deformity was 10° (5–15). There were no intraoperative complications but the patient with poor flexion required an arthrolysis and because of the poor result is under consideration for conversion to a conventional DFR. Two patients had follow-up periods of 3 months or less and are still in their early rehabilitation period. One patient in this group developed sepsis that resolved after an open washout. Conclusions: Our early results with this prosthesis, in the patients with adequate follow-up, have been good in the majority but the two cases of fair and poor knee flexion are disappointing. This particular problem may relate to design and technical factors, which will be discussed in detail.

Clear cell sarcoma of soft tissues is a rare, poorly understood tumour with little written about it in peer reviewed literature. The aim of this paper is to present a consecutive series of patients treated at our institution.

All patients were staged using the system of the musculo-skeletal tumour society (MSTS). The aim of surgery was to achieve a wide excision. Adjuvant chemotherapy or radiotherapy was used in some patients depending on the margins, age and general health of the patient. Follow-up comprised clinical examination, magnetic resonance imaging (MRI) of the tumour bed and chest x-rays. Patients were seen 3 monthly for the first 2 years and then 6 monthly.

Between 1997 and 2003 14 patients were included. There were 5 males and 9 females with a mean age of 49 years (21–82). Mean follow-up was 42 months (1–84). Seven tumours occurred in the upper limb and 7 in the lower limb. Four patients were lymph node positive at presentation. The mean maximum diameter of the tumour was 5.6 cm (2–8). Ten patients were referred prior to excision but 4 patients had already undergone inadvertent excision biopsy elsewhere. Four patients developed local recurrence and 3 patients developed metastases. Seven patients remain disease free, 2 have no active disease, 1 is alive with disease and 4 have died of the disease.

The 2 year survival in this series is 71%. Poor prognostic factors include positive lymph nodes at diagnosis, maximum diameter of the tumour greater than 5cm and incomplete initial excision. It is important that these patients are treated early and that wide excision is achieved. We recommend early referral to a recognised musculo-skeletal tumour centre.

Introduction: Spontaneous spinal epidural haematoma is an uncommon clinical problem which may lead to severe and permanent neurological deficit. The treatment options for spinal cord compression by extradural haematoma in the anticoagulated patient are limited. The majority of cases reported have been treated surgically.¹ Operative intervention carries a potential risk of extending the haematoma with further deterioration of the neurological deficit.

Methods: A case of paraplegia following spontaneous epidural haemorrhage is reported with a review of the prognostic factors that determine likely improvement in neurological function post-surgery.

Case report: A 59-year old man was referred to the regional Spinal Trauma Centre with a 34-hour history of severe lower back pain of sudden onset and 14 hour history of neurological deficit in both legs and urinary overflow incontinence. He had undergone aortic valve replacement two years previously, with subsequent anticoagulation with Warfarin. Examination showed complete paraplegia below L3 with grade 1 power on hip flexion only. On catheterisation, the residual volume of urine was 1200mls. The INR was 3.5. An MRI of the spine showed epidural haematoma that extended from the level of T11 to L5.

The patient was treated non-operatively. On discharge at 10 weeks he had normal sensation to L3 and grade 5-power on left knee extension and grade 4-power on the right. There was no motor recovery distal to this. He had a hypotonic neurological bladder with sufficient resting tone in the sphincter to prevent incontinence.

Discussion: Although associated with a definite mortality, surgical decompression of the spinal cord and evacuation of the haematoma improves neurological outcome and is the treatment of choice.¹ The decision to treat non-operatively should be based on the duration and severity of the neurological deficit. A literature review identifies neurological deficit greater than 12 hours and severe neurological deficit on presentation are poor prognostic indicators.² The prognosis for neurological recovery in this case was poor. In a patient with severe coexisting medical problems these factors can assist when making the decision to operate on an individual patient with spinal epidural haematoma.

Introduction: Anterior lumbar interbody fusion (ALIF) with posterior stabilisation is an established treatment for degenerative disc disease.¹ Some previous reports have advocated a goal of 360 degree fusion, and condemned posterior stabilisation as it does not achieve fusion of the posterior facet joints.² Others have claimed that the concept of a ‘locked pseudarthrosis’ gives satisfactory clinical results.³ There is also a contention that private or self-funding patients achieve better results after spinal fusion compared to those treated under compensation or Dept. Veterans Affairs (DVA) schemes.

Methods: Twenty patients who had undergone an ALIF with posterior stabilisation were retrospectively reviewed. All had a follow-up greater than 12 months. 13 patients were private and 7 non-private. The groups were aged and sex matched. Radiological assessment of fusion was made with reconstruction CT scans. Oswestry Disability Index (ODI) scores were recorded preoperatively, 6 months and 12 months post operation.

Results: Patients with locked pseudarthrosis showed no significant difference in outcome compared to those with radiological fusion. Both groups showed signifi cant improvement in ODI scores after ALIF (mean preop. = 52 – range 16-74; mean postop. = 18 – range 0-52; p< 0.01). There was a significantly greater improvement (p< 0.02) in ODI scores in private patients (mean reduction = 41 points) compared to worker’s compensation or DVA patients (mean reduction = 22 points).

Discussion: The results indicate that ALIF with posterior stabilisation can achieve good clinical results even with a ‘locked pseudarthrosis’. While there is no significant difference between outcomes in different health funding groups shown in the study, carefully patient select for this treatment is the key to success.

Introduction: Pelvic fixation is undertaken in order to restore stability to an unstable pelvis or correct severe scoliotic degeneration of the spine. Instability of the pelvic ring can result from resection of tumours, fractures of the pelvis or infection of the pelvic joints and bones. A number of methods for stabilising the pelvis have been described in the literature including the Galveston Reconstruction (GR)¹ and the triangular frame reconstruction (TFR)². These are associated with an improvement in functional ability, however failure of instrumentation or loosening often occurs.³ A recent mechanical analysis of these techniques has found the technique used in this hospital (GR) performed most poorly.²

Methods: A scoring system was developed from a retrospective analysis of 8 patients. The patients were categorised into two groups (high score and low score) based on age, presence of infection and serious non-associated comorbidities. A patient aged 60 years or over scored 5 points. Patients with bony infection scored 10 points. The presence of serious comorbidity including osteoporosis scored 5 points with minor comorbidities scoring 1 point.

Results: Eight patients who underwent pelvic fixation for varied indications (2 after resection of tumours, 1 fracture, 2 scoliotic degeneration, 3 for infection) were analysed. Three patients had a good functional improvement without loosening of screws beyond 1 year after surgery. These patients were otherwise healthy, relatively young and had no disease processes that affected local bone quality at the site of fixation or serious comorbidities. The other 5 patients all showed evidence of early screw loosening within one year. Of these patients, 2 had a number of serious comorbidities well recognised to compromise bone quality (osteoporosis, long term steroid use) and 3 had pre-existing extensive bony infection.

Discussion: Bone quality of the pelvic bones appears to be the primary predictor of long term functional outcome after pelvic fixation. The 5 patients who had a number of comorbidities well recognised to compromise bone quality all saw early screw loosening within 1 year. Since fixation of the pelvis requires extensive surgery necessitating both posterior and anterior approach and has a number of severe complications such as alteration of urinary, sexual and recto-sigmoid functions the benefit of pelvic fixation should be considered in light of these factors which appear to predict long term outcomes. Further prospective studies of patients undergoing pelvic fixation are required to validate our scoring system.

Introduction: Diaphyseal femoral allograft is well suited to anterior column reconstruction of the thoracolumbar spine due to its inherent structural properties and bio-compatibility. The Bridwell system of interbody fusion assessment¹ is based on plain x-rays and therefore lacks sensitivity. A new classification system of bony union is proposed using high-speed spiral CT imaging.

Methods: Twenty-six patients who underwent anterior thoracolumbar reconstruction for burst fracture using femoral allograft were followed for a minimum of 2 years. Each subject underwent high speed spiral CT scanning through the reconstructed region of the thoracolumbar spine and a classification system of graft to endplate union and central cancellous autograft incorporation was established.

The classification system reflects gradually increasing biological stability of the construct. Grade I (complete fusion) implies cortical union of the allograft and central trabecular continuity. Grade II (partial fusion) implies cortical union of the structural allograft with partial trabecular incorporation. Grade III (unipolar pseudarthrosis) denotes superior or inferior cortical non-union of the central allograft with partial trabecular discontinuity centrally and Grade IV (bipolar pseudarthrosis) suggests both superior and inferior cortical non-union with a complete lack of central trabecular continuity. Intra- and inter-observer error studies were carried out involving spinal surgeons, radiologists and trainees to examine reliability of the classification

Results: In this series 84% of cases demonstrated Grade I or Grade II characteristics. 1 case (4%) was identified as Grade IV. The classification showed good reliability with a kappa score of over 0.7

Discussion: Plain radiographs have always proved unsatisfactory for the accurate assessment of incorporation of grafts in the thoracolumbar spine. The use of CT imaging in the assessment of graft union has allowed a more accurate assessment of union. The classifi cation system presented allows a reproducible and relevant categorisation of allograft incorporation.

Introduction: The foot is an unusual site for presentation of Ewings tumour. Haemangioma of the vertebra is a common finding in adults, but is rarely reported in children.¹ Although rarely symptomatic, the lesion may cause diagnostic confusion particularly in the presence of comorbidity. A previous case report details an adult patient with a ‘pseudohaemangioma’ that was subsequently found to be an Ewings tumour.²

Methods: A review of the literature and a case report is presented of a boy with a Ewing’s sarcoma of the foot presenting with an asymptomatic lytic lesion in the spine.

Results: The 12-year-old male initially presented with pain and swelling in the right foot. Subsequent investigation and biopsy confirmed a diagnosis of Ewing’s sarcoma in the second metatarsal. The child received 5 cycles of combined chemotherapy, and the primary tumour was excised from the metatarsal with fibular graft reconstruction.

Part of the clinical work up had included an isotope bone scan, which revealed a focal area of increased uptake in the L1 vertebra. On MRI, the vertebral lesion had a ‘halo’ of high intensity signal with infraction of the upper vertebral endplate. There were no clinical symptoms arising from the vertebral lesion. The differential diagnosis of the L1 lesion suggested was either a meta-static Ewing’s tumour or an aggressive haemangioma. Given the possibility of a multifocal or metastatic lesion, a vertebrectomy and reconstruction with femoral allograft was performed. A second stage posterior stabilisation from T12 to L2 was performed. Histological examination of the resected vertebra revealed a benign capillary haemangioma. On recent review one year after treatment, the patient remains in remission from his tumour and has successful graft incorporation with minimal symptoms from his spine.

Discussion: Haemangioma is a benign tumour commonly found in the vertebral body. Asymptomatic spinal haemangiomas do not require surgical excision. Clinico-pathological distinction between vertebral haemangioma and metastatic disease can be difficult, particularly in children where the haemangiomata may be in a ‘blastic’ phase. The combination of an extremely unusual age of presentation and the presence of a separate malignant primary bone tumour in this patient introduced a significant clinical dilemma in treatment.

Introduction: There is increasing evidence that surgical treatment in tumour surgery can influence survival times. Renal cell carcinoma can lead to single or few sites of metastasis that are amenable to extirpative surgery with reconstruction in the spine¹. Such treatment can also be beneficial to improve quality of surviving years.

Methods: Retrospective cohort study of 10 consecutive patients treated for spinal metastatic renal cell carcinoma. Case note review and patient or general practitioner contact was used to ascertain number of metastases, treatment given, survival time from diagnosis and survival time from surgery. All primary tumours were treated with nephrectomy.

Results: Of the 10 patients, 6 had extirpative treatment, while 4 had palliative surgery including decompression of the neural elements. Patients treated with extirpative surgery to spinal metastases from a renal cell carcinoma primary had a significantly longer survival time from surgery to those treated with palliative decompressions alone. There were no significant differences in age or time from diagnosis to surgical treatment between groups. There were no cases of operative mortality, but significant intraoperative bleeding was encountered in extirpative treatment of the affected vertebra, despite preoperative embolisation.

Discussion: The role of surgical treatment in metastasis to the spine is of current interest. Our results have shown significant survival times are possible with extirpative treatment of renal metastases. Whilst this may not apply directly to metastases from other primary tumours, careful selection of cases and co-operation between spinal surgeons and oncologists is important to ensure maximal quality and length of survival for these patients. These cases are surgically challenging, and care is required to minimise and anticipate blood loss.

Aims: Firm bandaging of the knee following knee replacement may prevent bleeding into the joint by a tamponade effect, but the presence of a tight bandage around the knee may obstruct venous return and lead to thromboembolic complications. We have studied the pressure required, and then compared clinically the use of a compression bandaging with the use of either a drain, or a standard crepe bandage. Method: Transducers were used to measure the pressure achieved on the surface of the knee under different bandages, and within the knee following release of tourniquet. Three series of 50 patients have been compared: with compression bandaging from toes to mid-thigh, with crepe alone, or with suction drain and crepe. Results: The pressure within the joint at which tamponade occurs is 52–57 mm Hg. The pressure on the skin under a properly applied compression bandage is between 28 and 32 mmHg and this controls bleeding within the joint. Patients treated with compression bandaging recovered quicker from the operation had a shorter hospital stay and a greater range of ßexion on discharge. They had no swelling of the limb, rarely suffered a tense haemarthrosis and had fewer complications. Conclusions: The use of compression bandage incorporating the foot and calf following knee replacement surgery confers speciþc advantages over the use of crepe bandage alone.

INTRODUCTION: Regular review [1, 2] of cervical injuries occurring in rugby players is an important step toward maximising the safety of the players. It is hoped that the recognition of recurring patterns of injury would lead to appropriate rule modification by the regulatory bodies of the sport. Serious cervical injuries in rugby have been reported to occur by a range of mechanisms, including those involved with scrummaging, tackling, rucking and mauling.

Spinal flexion is the commonest mechanism of injury and has been associated with scrum engagement, scrum collapse, rucking or mauling, and mistimed tackling. The second most common mechanism of cervical spinal injury is hyper-extension. This commonly occurs during tackling, particularly the ‘gang tackle’ involving several participants simultaneously, where sudden deceleration of a player’s head may lead to cervical hyperextension, focal spinal stenosis and potential damage to the spinal cord by a “pincer” mechanism.

The most commonly reported levels of injury are C5/6 and C4/5 [3].

METHODS: A retrospective review of neck injuries presenting to a major spinal injuries facility and resulting from all codes of football (rugby union, rugby league, soccer, indoor soccer and touch) was conducted and 38 cases identified.

RESULTS: Of the 38 patients, 14 were injured playing rugby union, 15 rugby league, three soccer, one indoor soccer, one touch football and four were playing an unidentified code. Six players were injured while scrummaging, five rugby union and one rugby league. 21 people were injured as tacklees, four as tacklers and two with unspecified involvement in a tackle. One person was injured whilst “heading” the ball, and three people were injured in a non-contact or unspecified action. At final follow-up, four people were found to be quadriplegic (ASIA A), 10 quadriparetic (ASIA B – 0 C –1 and D –9) and 24 recovered completely (ASIA E).

We aim to present an 18 Month Review of one Surgeons Practice Involving 16 Patients with 3 or 4 part Fractures or 3 part Fracture-Dislocations of the Proximal Humerus in patients under 60 years of age.

Management principles include anatomic reduction, internal fixation and early movement.

The implants used in this series include:

The PLANTAN PLATE from ATLANTECH

The STRATEC 4.5 mm ANGLE BLADE PLATE

The POLARUS NAIL and various small cannulated screw systems.

3 patients were treared with minimal fixation, 5 with the AO Bladeplate, 4 with the PLANTAN plate and 4 with the Polarus nail.

Surgical Treatment, Radiographic and Clinical Outcomes will be reviewed. Anatomic considerations, surgical technique and outcomes will be discussed.

Purpose: In this ongoing trial we are analysing the performance of both a fixed bearing total knee replacement and a mobile bearing total knee replacement using gait analysis and a patient-based questionnaire. We aim to find out if there is a difference in the functional performance of the two types of prosthesis.

Method: Patients are taken from the in-patient waiting list of three consultants and introduced to the trial if deemed suitable. Each patient is analysed once pre-operatively and on three occasions post-operatively (6 weeks, 3 months and 1 year) at the university gait analysis laboratory. At each visit various anthropological measurements are recorded and the patient fills in an “Activities of Daily Living” questionnaire. After calibration and measurement of the passive range of motion of both knees each patient has their gait analysed over a series of six walks using a standard 5 camera system with skin marker clusters, the kinematic data from this is supplemented with force-plate recordings and video analysis of each set of walks. Data is recorded for both of the patient’s knees. The staff in the gait analysis laboratory are blinded as to which prosthesis has been used for each patient in an effort to eliminate bias.

We present our methodology and some preliminary results.

Introduction: The natural history of bone bruises of the knee and their clinical significance remains unclear with only a few short term studies in the literature.

Aim: This study was designed to try and elucidate the long term outcome of bone bruises of the knee following trauma.

Materials and Methods: 60 patients with bone bruises identified in their knees by MRI scans following trauma were included in the study. All patients were reviewed in a research clinic with a minimum 5 year follow up. A detailed history including mechanism of injury, persistent symptoms and functional status was obtained. Clinical examination to identify intra-articular pathology was then undertaken. All patients had a repeat MRI scan of the knee. The relationship between the injury and the bone bruise, the effect of treatment if any and the long term outcome of such lesions was studied.

Results: 80% of the patients had a twisting injury with our without a hyperextension of valgus/varus force. 58% of our series had ACL injuries and 68% of the bone bruises were in the medial condyle. 72% of the patients did not return to their pre-accident status and had continuing symptoms although the majority of them did not have signs of clinical instability. There was MRI evidence of lasting sequelae of bone bruises in the majority of patients. Detailed results will be discussed.

Conclusions: bone bruises identified on MRI following trauma to the knee are significant lesions with the potential for long term sequelae.