Non-invasive sampling of tumor-derived genetic material in circulation through liquid biopsy may be very beneficial for an accurate diagnosis and evaluation of response to treatment in patients with malignant and benign soft tissue tumors. We previously showed that tumor-derived genomic aberrations can be detected in plasma of patients with leiomyosarcoma (LMS) and leiomyoma (LM). In LMS patients, we also showed that the levels of circulating tumor DNA (ctDNA) correspond with response to treatment. We developed an approach tailored to genomic profile of LMS (characterized by intermediate levels of point mutations and copy number alterations, CNAs). Based on TCGA data, we designed a panel of 89 most frequently mutated genes in LMS, which we profiled in plasma DNA by deep sequencing. In parallel, plasma samples were analyzed by shallow whole genome sequencing for detection of CNAs. With this approach, we detected ctDNA in 71% (20/28) of samples from 6/7 patients with advanced disease with >98% specificity. The combination approach for orthogonal profiling of point mutations and CNAs proved to increase the sensitivity of ctDNA detection. Currently, we seek to further improve the sensitivity of ctDNA detection by refining our capture panel and tracking LMS-specific DNA methylation markers in circulation, in addition to point mutations and CNAs. The ultimate goals of our ctDNA studies are 1) to develop a highly sensitive assay for evaluation of response to therapy and long-term surveillance for patients with LMS, and 2) to develop a blood-based test for accurate pre-operative distinction between LMS and LM.

To identify LMS-specific DNA methylation markers, we analyzed a test cohort of 76 LM, 35 uterine LMS and 31 extra-uterine LMS by Illumina Infinium EPIC arrays. We identified differentially methylated CpGs between LM and uterine LMS, and between LM and all LMS using a newly developed custom pipeline in R. The results of this analysis are currently being validated in a new dataset of 41 LM and 153 LMS generated by our group. Recently published (PMID: 34301934) genomic data from new 53 LMS samples are used to refine the panel of the most frequently mutated genes that we identified previously in the LMS TCGA data.

Our preliminary analysis of test cohort revealed >270 differentially methylated CpGs between LM and uterine LMS, and >1000 differentially methylated CpGs between LM and all LMS. The preliminary analysis of genomic data shows that the initial panel of 89 frequently mutated genes could be substantially narrowed down to cover only selected tumor suppressor genes. Once validated, these results will be used to refine the ctDNA assay for LMS and LM.

Our results point to multiple epigenetic markers that could be used for ctDNA profiling, in addition to point mutations or CNAs. Further validation will allow us to select the most reliable LMS- and LM-specific DNA methylation markers and the most frequently mutated regions across independent datasets, and these markers will be incorporated into our new ctDNA test for a concurrent detection of point mutations, CNAs and DNA methylation markers in circulation.

Abstract

Abstract

Aims

The aim of this meta-analysis is to assess the association between exchange of modular parts in debridement, antibiotics, and implant retention (DAIR) procedure and outcomes for hip and knee periprosthetic joint infection (PJI).

Infections are among the main complications connected to implantation of biomedical devices, having high incidence rate and severe outcome. Since their treatment is challenging, prevention must be preferred. For this reason, solutions capable of exerting suitable efficacy while not causing toxicity and/or development of resistant bacterial strains are needed. To address infection, inorganic antibacterial coatings, and in particular silver coatings, have been extensively studied and used in the clinical practice, but some drawbacks have been evidenced, such as scarce adhesion to the substrate, delamination, or scarce control over silver release.

Here, antibacterial nanostructured silver-based thin films are proposed, obtained by a novel plasma-assisted technique, Ionized Jet Deposition (IJD). Coatings are obtained by deposition of metallic silver targets. Films thickness is selected based on previous results aimed at measuring extent and duration of silver release and at evaluating toxicity to host cells (fibroblasts). Here, composition (grazing incidence XRD) and morphology (SEM) of the obtained coatings are characterized for deposition onto different substrates, both metallic and polymeric. For heat sensitive substrates, possible alterations caused by coatings deposition in terms of morphology (SEM) and composition (FT-IR) is assessed. Then, a proof-of-concept study of the capability of these films to inhibit microbial biofilm formation is performed by using two different supports i.e., the Calgary Biofilm Device and the microplates. To the best of the Authors knowledge, this is the first study describing the application of specific anti-biofilm analyses to nanostructured coatings. In particular, anti-biofilm activities are tested against the following pathogenic strains: Escherichia (E.) coli NCTC12923, Staphylococcus (S.) aureus ATCC29213 and S. aureus 86. Among these, the strain 86 is not only pathogen but it also possesses several antibiotic resistance genes, allowing the evaluation of the utilization of nanostructured coatings as an alternative anti-microbial system to face the global threat of antibiotic resistance.

Results indicate that films deposited from silver targets are composed of nanosized aggregates of metallic silver, indicating a perfect transfer of composition from the deposition target to the coatings.

Results obtained here indicate that the films have significant antibacterial and antibiofilm activity. In addition, they prove that the system can be successfully applied for evaluation of coatings antibacterial efficacy for biomedical applications.

Patients with cancer and bone metastases can have an increased risk of fracturing their femur. Treatment is based on the impending fracture risk: patients with a high fracture risk are considered for prophylactic surgery, whereas low fracture risk patients are treated conservatively with radiotherapy to decrease pain. Current clinical guidelines suggest to determine fracture risk based on axial cortical involvement of the lesion on conventional radiographs, but that appears to be difficult. Therefore, we developed a patient-specific finite element (FE) computer model that has shown to be able to predict fracture risk in an experimental setting and in patients. The goal of this study was to determine whether patient-specific finite element (FE) computer models are better at predicting fracture risk for femoral bone metastases compared to clinical assessments based on axial cortical involvement on conventional radiographs, as described in current clinical guidelines.

45 patients (50 affected femurs) affected with predominantly lytic bone metastases who were treated with palliative radiotherapy for pain were included. CT scans were made and patients were followed for six months to determine whether or not they fractured their femur. Non-linear isotropic FE models were created with the patient-specific geometry and bone density obtained from the CT scans. Subsequently, an axial load was simulated on the models mimicking stance. Failure loads normalized for bodyweight (BW) were calculated for each femur. High and low fracture risks were determined using a failure load of 7.5 × BW as a threshold. Experienced assessors measured axial cortical involvement on conventional radiographs. Following clinical guidelines, patients with lesions larger than 30 mm were identified as having a high fracture risk. FE predictions were compared to clinical assessments by means of diagnostic accuracy values (sensitivity, specificity and positive (PPV) and negative predictive values (NPV)).

Seven femurs (14%) fractured during follow-up. Median time to fracture was 8 weeks. FE models were better at predicting fracture risk in comparison to clinical assessments based on axial cortical involvement (sensitivity 100% vs. 86%, specificity 74% vs. 42%, PPV 39% vs. 19%, and NPV 100% vs. 95%, for the FE computer model vs. axial cortical involvement, respectively). We concluded that patient-specific FE computer models improve fracture risk predictions of femoral bone metastases in advanced cancer patients compared to clinical assessments based on axial cortical involvement, which is currently used in clinical guidelines. Therefore, we are initiating a pilot for clinical implementation of the FE model.

Calcium phosphates-based coatings have been widely studied to favour a firm bonding between orthopaedic implants and the host bone. To this aim, thin films (thickness below 1 μm) having high adhesion to the substrate and a nanostructured surface texture are desired, capable of boosting platelet, proteins and cells adhesion. In addition, a tunable composition is required to resemble as closely as possible the composition of mineralized tissues and/or to intentionally substitute ions having possible therapeutic functions. The authors demonstrated nanostructured films having high surface roughness and a composition perfectly resembling the deposition target one can be achieved by Ionized Jet Deposition (IJD). Highly adhesive nanostructured coatings were obtained by depositing bone-apatite like thin films by ablation of deproteinized bovine bone, capable of promoting host cells attachment, proliferation and differentiation. Here, biomimetic films are deposited by IJD, using biogenic and synthetic apatite targets. Since IJD deposition can be carried out without heating the substrate, application on heat sensitive polymeric substrate, i.e. 3D printed porous scaffolds, is investigated.

Biogenic apatite coatings are obtained by deposition of deproteinized bone (bovine, ovine, equine, porcine) and compared to ones of stoichiometry hydroxyapatite (HAp). Coatings composition (FT-IR-ATR, FT-IR microscopy, XRD, EDS) and morphology (SEM, AFM) are tested for deposition onto metallic and 3D-printed polymeric substrates (polyurethane (PU)). Different post-treatment annealing procedures for metallic substrates are compared (350–425°C), to optimize crystallinity. Then, uniformity of substrate coverage and possible damage caused to the polymeric substrate are studied by SEM, DSC and FT-IR microscopy.

Biogenic coatings are composed by carbonated HAp (XRD, FT-IR). Trace ions Na⁺ and Mg²⁺ are transferred from deposition target to coating. All coatings are nanostructured, composed by nano-sized globular aggregates, of which morphology and dimensions depend on the target characteristics. As-deposited coatings are amorphous, but crystallinity can be tuned by post-treatment annealing. A bone-like crystallinity can be achieved for heating at ≥400°C, also depending on duration. When deposited on 3D-printed PU scaffolds, coatings, owing to sub-micrometric thickness, coat them entirely, without altering their fibre shape and porosity.

Obtained biomimetic bone apatite coatings can be deposited onto a variety of metallic and polymeric biomedical devices, thus finding several perspective applications in biomedical field.

Abstract

Introduction

In the United States, cementless femoral fixation remains the dominant mode of fixation for femoral neck fractures, despite strong worldwide registry data that supports cemented fixation. The reason for this discrepancy remains unknown, controversial and often difficult to compare due to multiple variables. The purpose of this study was to evaluate a matched cohort of patients undergoing arthroplasty for femoral neck fractures and assess outcomes of revisions, periprosthetic fractures and mortality.

Introduction

Reverse total shoulder arthroplasty (RTSA) is rapidly being adopted as the standard procedure for a growing number of shoulder arthropathies. Though short-term outcomes are promising, mid- and long-term follow-ups present a number of complications – among them, humeral stem and glenosphere component loosening. Though not the primary complication, previously reported aseptic loosening required revision in 100% of cases. As the number of patients undergoing RTSA increases, especially in the younger population, it is important for surgeons to identify and utilize prostheses with stable long-term fixation. It has previously been shown in the hip and knee literature that implant migration in the first two years following surgery is predictive of later failure due to loosening in the 5=10-year postoperative window. The purpose of this study is to, for the first time, evaluate the pattern and total magnitude of implant migration in reverse shoulder arthroplasty using the gold standard imaging technique radiostereometric analysis (RSA).

Introduction

Reverse total shoulder arthroplasty (RTSA) is a semi-constrained joint replacement with an articulating cobalt-chromium glenosphere and ultra-high molecular weight polyethylene (PE). Because of its limited load bearing, surgeons and implant manufacturers have not elicited the use of highly cross-linked PE in the shoulder, and to date have not considered excessive PE wear in the reverse shoulder a primary concern. As the number of shoulder procedures is expected to grow exponentially in the next decade, however, it is important to evaluate how new designs and bearing materials interact and to have an understanding of what is normal in well-functioning joint replacements. Currently, no in vivo investigation into RTSA PE wear has been conducted, with limited retrieval and simulation studies. In vitro and in silico studies demonstrate a large range in expected wear rates, from 14.3 mm³/million cycles (MC) to 126 mm³/MC, with no obvious relationship between wear rate and polyethylene diameter. The purpose of this study is to evaluate, for the first time, both volumetric and linear wear rates in reverse shoulder patients, with a minimum six-year follow-up using stereo radiographic techniques.

Purpose of the study and background

A 2011 Cochrane review concluded that spinal manipulative therapy (SMT) is no better than other interventions for reducing pain and improving function in chronic low back pain (CLBP). Using individual participant data (IPD) from trials has advantages, among others: a more precise estimate of the effect and the potential to identify moderators. Our objective was to assess the effect of SMT in adults with CLBP and to identify relevant moderators.

Introduction

Total shoulder arthroplasty is the fastest growing joint replacement in recent years, with projected compound annual growth rates of 10% for 2016 through 2021 – higher than those of both the hip and knee combined. Reverse total shoulder arthroplasty (RTSA) has gained particular interest as a solution for patients with irreparable massive rotator cuff tears and failed conventional shoulder replacement, for whom no satisfactory intervention previously existed. As the number of indications for RTSA continues to grow, so do implant designs, configurations, and fixation techniques. It has previously been shown that continuous implant migration within the first two years postoperatively is predictive of later loosening and failure in the hip and knee, with aseptic loosening of implant components a guaranteed cause for revision in the reverse shoulder. By identifying implants with a tendency to migrate, they can be eliminated from clinical practice prior to widespread use. The purpose of this study is to, for the first time, evaluate the pattern and magnitude of implant component migration in RTSA using the gold standard imaging technique radiostereometric analysis (RSA).

Aim

There is a theoretical advantage for immediate postoperative start of rifampicin after debridement, antibiotics and implant retention (DAIR). Anti-biofilm treatment may be mostly needed during the first postoperative days in order to prevent new biofilm formation. However, there are concerns with regard to development of rifampicin resistance if rifampicin is started too early. Rifampicin monotherapy will rapidly result in rifampicin resistance, but this may not occur when prescribed as part of combination antimicrobial therapy and after thorough surgical debridement. We hypothesized that in this setting the probability of development of rifampicin resistance is very low. We evaluated the frequency of development of rifampicin resistance in patients with acute staphylococcal PJI who were treated with DAIR followed by immediate postoperative start of rifampicin in combination with a betalactam or glycopeptide.

Aim

Early discharge of patients after joint arthroplasty leaves patients responsible for monitoring their postoperative wound by themselves. This might result in a delayed presentation of postoperative complications. The use of a mobile woundcare app by patients after arthroplasty might result in (1) earlier report of complications, (2) an increase in patient satisfaction and (3) insight in the incidence and duration of postoperative wound leakage. Therefore, the ease of use and perceived usefulness of using a postoperative mobile woundcare app in patients after joint arthroplasty was investigated.

Osteoarthritis (OA) is a leading cause of joint deformity and functional limitation. An imbalance of anabolic and catabolic activity results in destruction of the extracellular matrix of articular cartilage. There is evidence to support the role of DNA methylation in the pathogenesis of OA, but the effect of other epigenetic modifiers is yet to be described. This study looks at the effect of novel epigenetic modulators, PFI-1, a bromodomain inhibitor, and SGC707, a histone methytransferase inhibitor, and their effects on gene expression in the pathogenesis of OA. Chondrocytes were extracted from OA femoral heads (n=6), cultured and incubated. Samples were treated with media alone (control), interleukin 1-beta (IL-1β) plus oncostatin M (OSM) alone, or in combination with increasing concentrations of PFI-1 or SGC707. Levels of expression of iNOS, COX2, IL8, IL1B, matrix metalloproteinase-13 (MMP13), RUNX2 and COL9A1 were measured using qRT-PCR, and expressed relative to GAPDH. PFI-1 (0.5 and 5µM) suppressed expression of catabolic genes in OA chondrocytes, at basal levels and when co-stimulated with IL-1β+OSM. Catabolic gene expression decreased (iNOS, COX2, IL-8, IL-1β and MMP), and RUNX2 expression was also supressed. There was no effect on expression of the anabolic gene COL9A1. SGC707 (0.1 and 1µM) did not induce a reduction in expression of all the catabolic genes. This study has demonstrated that PFI-1 has a potent protective effect against cartilage degradation, by modulating the expression of catabolic genes in OA chondrocytes. This further validates the role of epigenetics in OA, with implications for therapeutic interventions in the future.

INTRODUCTION

The goal of the study was to perform quality control with a commercially available navigation system when introducing PST technique at our academic department. The learning curve was assessed by the Cumulative Sum (CUSUM) test. We hypothesized that the PST process for TKA was immediately under control after its introduction when analyzed with the CUSUM technique.

INTRODUCTION

The patient-specific templates (PST) for total knee arthroplasty (TKA) have been developed to improve accuracy of implantation, decrease operating time and decrease costs. There remains controversy about the accuracy of PST in comparison with either navigated or conventional instruments. Furthermore, the learning curve after introducing PST has not been well defined. The goal of the present study was to perform quality control with a commercially available navigation system and the CUCUM test when introducing PST technique at our academic department.

Introduction

An appropriate positioning of a total knee replacement (TKR) is a prerequisite for a good functional outcome and a prolonged survival. Navigation systems may facilitate this proper positioning. Patient specific templates have been developed to achieve at least the same accuracy than conventional instruments at a lower cost. We hypothesised that there was no learning curve at our academic department when using patient specific templates for TKR instead of the routinely used navigation system.

High-dose antibiotic-loaded acrylic cement (ALAC) is used for managing periprosthetic joint infections (PJIs). The marked increase in resistant high-virulence bacteria is drawing the attention of physicians towards alternative antimicrobial formulations to the routinely used antibiotics. To date, few studies simultaneously investigated the elution properties of a broad range of antibiotics. The aim of thepresent in-vitrostudy was to determine the elution kinetics of 14 different high-dose ALACs.

All the ALAC samples showed a burst release of antibiotics in the first hour, progressively decreasing overtime, and elution curves strictly adhered to a non-linear regression analysis formula. Among aminoglycosides, commonly addressed as the most appropriate antibiotics to be loaded into the bone cement, the highest elution rate was that of tobramycin. Among the glycopeptides, commonly used to treat PJIs because of the prevalence of aminoglycoside resistance, vancomycin showed better elution in comparison with teicoplanin. Clindamycin, that can be associated with aminoglycosides to prepare ALACsshowed the highest absolute and relative elutions among all the tested formulations. A noticeable elution was also detected for colistin, an antibiotic of last resort for treating multi-drug resistant bacteria.

The current study demonstrates theoretical advantages in the preparation of ALAC for some antibiotics notroutinely used in the clinical setting for PJIs. The use of these antibiotics based on the infecting bacteria sensitivity may represent an useful option for physicians to eradicate PJIs. In vivo testing should be considered in the future to confirm the results of this study.

Background:

With the increase in the average age of the population, the incidence of symptomatic rotator cuff tears will also increase. Combined with more access to information via the internet etc., the patient population is more informed of the treatment modalities available and is expecting good reproducible results of their surgeries.

Background

Combined physical and psychological (CPP) programmes are widely recommended for Chronic Low Back Pain (CLBP) patients, but not often implemented. Patients with longstanding CLBP participating in a two-week CPP programme improve in functional status and quality of life and this is maintained at two-year follow up. One-year follow-up data is available of 955 participants.

Purpose:

The objective of this study was to determine the tensile strength of the different components of the rotator cuff tendons and their relationship to rotator cuff tears.

Purpose:

To determine the insertion of the different layers of the rotator cuff and apply it to rotator cuff tears. Anatomical insertion of the rotator cuff holds the key to a proper anatomical repair.

Segmental excision of long-bone sarcomas can require complex reconstruction, often resulting in the use of prosthetic replacements at a young age.

The use of vascularised free fibula grafting (VFFG) is well established as a reconstruction modality in sarcoma surgery.

Background

Giant cell tumours of bone (GCT) are benign bone tumours with a locally aggressive character. Local recurrence is considered the main complication of surgical treatment and is described in up to 50% of patients. Intralesional curettage with the use of adjuvants like phenol or polymethylmetacrylate (PMMA) is recommended as initial treatment, significantly decreasing the risk of recurrence. However, risk factors for local recurrence in skeletal GCT have not yet been firmly established and a golden standard for local therapy remains controversial.

INTRODUCTION

Many studies have looked at the effects of titanium tibial baseplates compared to cobalt chrome baseplates on backside wear. However, the surface finish of the materials is usually different (polished/unpolished) [1,2]. Backside wear may be a function not only of tray material but also of the locking mechanism. The purpose of this study was to evaluate the wear performance of conventional polyethylene inserts when mated with titanium tibial trays or cobalt chrome tibial trays that both have non-polished topside surfaces.

Introduction

Local recurrence of Giant cell tumours of bone (GCT) is considered the main complication of surgical treatment (50%). Intra-lesional curettage with adjuvants like phenol or polymethylmethacrylate (PMMA) is recommended as initial treatment, decreasing the risk of recurrence. However, risk factors for local recurrence in skeletal GCT have not yet been firmly established and a golden standard for treatment remains controversial.

Aim of this study is identification of risk factors for recurrence in GCT, specifically after intra-lesional curettage with or without adjuvants.

Purpose

The treatment of C2 fractures with collar, halo or surgery can all be justified depending on the patient. In our unit, primary treatment is with a halo: in a previous study presented at BASS we found an 85% fusion rate. In a follow on study, we wished to assess the outcome in those patients who underwent surgical treatment.

BACKGROUND

Although osteoarthritis (OA) is not an inflammatory arthritis, a characteristic feature of OA is increased production of pro-inflammatory cytokines, such as interleukin 1beta (IL-1b), by articular chondrocytes. In fact, the degree of articular inflammation is often associated with disease progression; indicating that this process probably contributes to articular damage. Suppressor of cytokine signalling (SOCS) proteins are, as the name suggests, inhibitors of cytokine signalling that function via the JAK/STAT pathway (Janus kinase/signal transducers and activators of transcription). Eight SOCS proteins, SOCS1-SOCS7 and CIS-1 (cytokine-inducible SH2-domain-1 with similar structure to the other SOCS proteins) have been identified, of which, SOCS1-3 and CIS-1 are the best characterised. Reduced expression of SOCS proteins would be predicted to result in increased cytokine responsiveness and thereby could contribute to OA pathology.

The purpose of this study was to compare the outcome, complications and survival of the three most commonly used surgical reconstructions of the proximal humerus in adult patients after trans-articular tumour resection.

To review the accuracy of our systematic process in preventing wrong level lumbar microdiscectomy.

X-ray is used to identify the correct level for the skin incision to be made, x-ray is again used if the surgeon is in doubt prior performing the flavotomy. Following a lumbar microdiscectomy a Watson Chane is inserted into the empty disc space and an intra-operative x-ray is taken to confirm the level the discectomy has occurred. Observers A and B independently reviewed intra-operative x-ray in patients undergoing lumbar microdiscectomies and correlated the accuracy of the x-ray in determining correct level surgery against the pre-operative MRI scan and the preposed level of surgery.

123 patients, 66 males and 57 females underwent 127 lumbar microdiscectomy procedures between 2007 and 2009. The levels where surgery occurred are;- L2/3 -1 patient, L3/4–8 patients, L4/5–53 patients and L5/S1-65 patients.

Kappa coefficient was used to determine inter-observer and Pearson Correlation coefficient was used to determine the X-ray and MRI relationship

Percentage of patients who required a pre-flavotomy x-ray level check are:- L2/3–100%, L3/4-63%, L4/5–45%, and L5/S1–40%. Pearson's correlation in confirming the level lumbar microdiscectomy was performed using final x-ray and the pre-operative MRI scan was 1. Kappa coefficient between observer A and B was 1.

This process of using intra-operative x-ray in determining the exact level where lumbar microdiscectomy was performed is 100% accurate. This is our standard process in preventing wrong level surgery for lumbar microdiscectomy.

The Royal Liverpool and Broadgreen University Hospital, Liverpool, UK

Plasmacytoma is the localised form of multiple myeloma, which can affect any part of the body including the axial skeleton (Kelly et al, 2006; Ampil et al, 1995). These myelomas/plasmacytomas arise from one malignant clone of cells, which secrete the same type of immunoglobulin. Where the clone of cells remains localised, it is known as plasmacytoma, but when there is spread of the malignancy to multiple bones and marrow, it is known as multiple myeloma (Boccadoro and Pileri, 1995).

We present a case of solitary sacral bone plasmacytoma (SBP), in a seventy year old man which presented as low back pain, following a fall. He was neurologically intact, and had no sphincteric incontinence, but MRI revealed a large expansile lesion in S1, which caused severe spinal stenosis, involving the left L5 exiting foramen, with an irregular area of low signal posteriorly. Bone scan showed increased tracer uptake in L5 and a mixed hot/photopaenic appearance in the mid-sacral region indicating tumor involvement. Myeloma screen confirmed that the serum IgA was high, with positive kappa monoclonal band, positive Bence Jones Protein (BJP), normal IgM and IgG, and normal calcium profile. CT-guided biopsy revealed sheets of mature plasma cells, consistent with the diagnosis. Fine needle aspiration biopsy of an enlarged groin lymph node revealed neoplastic infiltration, consistent with myeloma. Skeletal survey and CT chest/abdomen/pelvis (CAP) were not contributory. The patient had six courses of radiotherapy and improved remarkably, and is being considered for chemotherapy as well as follow up in the out-patients' department.

Purpose of the study: Dementia in the elderly subject aged over 75 years is currently an important public health problem. An important part of the activity in orthopaedic surgery involves this age group. In 2007, 16,812 elderly persons aged over 75 years were hospitalised in our University Hospital (769 in orthopaedic surgery): 1380 patients were considered demented (40 in orthopaedic surgery). The purpose of this work was to evaluate the cognitive function of this population in a teaching hospital unit of orthopaedic and traumatology surgery where the prevalence of dementia appears to be underestimated.

Material and methods: Data were collected over a period of four years. This study concerned 113 patient, including 83 women, mean age 81.8 years (range 75–92). The reason for hospitalisation was predominantly fracture of the proximal femur (73%); thirty patients had hip, knee or shoulder arthroplasty and 24 other situations. The Mini Mental State Examination (MMSE) was performed.

Results: The MMSE could be interpreted for 100 patients: < 24 for 33, 24 to 26 for 29 and > 27 for 38. Among the 24 patients with no cognitive disorder known before hospitalization (nine patients known to be demented were removed from the analysis) and for whom the MMSE was completed entirely, the most frequent alterations were noted for attention, calculation, and recall-memory items.

Discussion: Finally, one-third of the subjects aged over 75 years and hospitalized in our unit presented signs of altered cognitive function according to the MMSE(< 24). This score is one of the criteria for frailness of the elderly subject. This population has an unstable precarious medicosocial status with defective adaptation to stress and change in environment. These persons are exposed to a high risk of morbidity, mortality, dependence, longer hospital stay and institutionalization. The purpose of this screening is to improve management for these patients by proposing more specifically adapted care.

Conclusion: It is thus indispensable to screen for cognitive disorders systematically in patients aged over 75 years hospitalized in a surgery unit. The MMSE score can be used for this purpose. This work is in favour of a physician or better a geriatrician within the unit who could be financed directly by his-her own sector of activity.

Purpose of the study: Conventional techniques for implantation of a TKA allow a neutral mechanical axis (HKA 180±3) in 70 to 86% of patients. The purpose of this work was to evaluate the contribution of intraoperative radiologic assistance for this objective.

Material and methods: We conducted a prospective randomised study in a single-operator consecutive series of cemented TKA, model TC-SB, excluding revisions and frontal deviations > 25. The series included 65 women and 39 men, mean age 73 years. All operations were performed on a radiolucent table. An extramedullary guide was used for the tibial cut and an intramedullary guide for the femoral cup. Patient randomisation was done after the cuts. According to the randomisation, the orientation of the cuts in the frontal plane was measured radiographically using a fluoroscope and an aiming plate situated on the hip, then the ankle. Secondary cuts were made if the angular deviation was greater than 1°. The position of the TKA assisted by the fluoroscope (group R+, n=52) and that of the non-assisted TKA (group R-, n=52) was assessed on the digitalised goniometry.

Results: Mean operative time was 70 minutes in group R+ and 59 minutes in group R-. In group R+, the mean mechanical alignment was 3.9 varus preoperatively and 0.13 valgus postoperatively (5 valgus to 3 varus) with 91% in the ±3 range. In group R-, the mean mechanical alignment was 6.7 varus preoperatively and 0.06 varus postoperatively (6 varus to 5 valgus) with 80% of the cases in the ±3 range. The standard deviation was 2 in group R+ and 2.7 in group R-, with no significant difference.

Discussion: The accuracy of the implantation obtained with the conventional instrumentation for the TC-SB prosthesis is among the best reported in the literature. Intraoperative radiological assistance enabled a tighter spread of the results around the mechanical alignment. The technique was simple to use and precise. The mean duration of exposure to the fluoroscope was 3 s (PDS 3 – 35 gray cm²).

Conclusion: We reserve this assistance in priority for patients with major bone deformities or medullary obstacles.

Purpose of the study: Restrained implants with intrinsic stability guaranteed by a large central stem have been developed for revision knee arthroplasty, irrespective of the underlying cause. Successful restraint implies excellent fixation of the prosthetic implants which can be obtained using press-fit centromedullary stems. The purpose of this work was to assess the long-term results of this mode of fixation in this indication and to search for clinical correlations with potential radiological images around the stems.

Material and methods: We report 46 cases of Sigma^®PFC TC3 revision total knee prostheses reviewed retrospectively at two years with a mean follow-up of eight years. Mean age at surgery was 68 years. Revision was indicated for aseptic loosening (n=24) and septic loosening (n=22). The knee society criteria were used for the clinical evaluation. Radiographic measurements were made semiautomatically with the Imagika^® software.

Results: The mean clinical score improved from 42 points preoperatively to 84.7 at two years and 83.7 at last follow-up. Outcome was excellent (n=30), good (n=7), fair (n=1) and poor (n=1). The mean function score improved from 34.3 preoperatively to 69.1 at two years and 64.2 at last follow-up. Radiographic alignment was correct in all cases. The press-fit effect was observed for 63% of the femoral implants and 76% for the tibial implants. Around the stems, 57% of the implants exhibited condensation lines and 23% lucent lines measuring less than 2 mm. There was no relation between radiological findings and the clinical or functional scores. There were two failures, one for frontal instability at six years and the other for aseptic loosening at eight years. Excepting these two cases, there was one case of femoral implant migration with no clinical expression. For all other patients, the radiographic image remained unchanged between the two year check-up and the final follow-up.

Discussion: Thee presence of lucent lines or condensation lines is well known for this type of implant with long centromedullary stems. Nevertheless, this is the first clinical series evaluating the clinical impact of these radiographic images. In our opinion, these images are related to the relative mobility of these implants which should be checked regularly, although no long-term clinical expression occurs. For us, this type of implant enables good function and long-term stability.

Purpose: Recognition of the glenoid version is important for evaluation of different pathologies. There is no consensus on method to use to evaluate version. The purpose of this study was to compare different measurement strategies in one hundred-sixteen (116) patients with shoulder CT-scans.

Method: Scapula CT-scan axial images were revised and the cut below the base of the coracoid was selected. The glenoid version was measured according to the Friedman method (FM) and the “scapula body” methods (BM). In case of B2 glenoid three different reference lines have been measure: the neo-glenoid NG (posterior erosion surface), paleo-glenoid PG (original glenoid surface) and the intermediate-glenoid IG (line from anterior and posterior edge). Three orthopaedic surgeons independently examined the images two times and intra/inter-observer reliability was calculated using Intra-Class Correlation (ICC). The objective of this paper is to define which method shows best reliability.

Results: Group 1 (B2 excluded n=53): The average glenoid version was significantly different between two measurement techniques for all three observers, with an average of – 7.29° for BM technique and – 10.43° for FM. Intra-observer reliability was excellent for both methods (ICC: 0.958–0.979 for FM; 0.940–0.970 for BM). Inter-observer reliability was excellent for both methods (FM: ICC= 0.977; BM: ICC= 0.962). The light superiority of the first method was not significant. For group 2 – B2 glenoid (n=63): six different measures of version were taken resulting by two scapula reference line (FM and BM) and three glenoid reference line (PG, IG, NG). The average glenoid versions were significantly different (p0.82). The inter-observer reliability were also very-good or excellent for all methods (ICC > 0.79). The most reliable method for measurement of B2 glenoid version was the association of the Friedman line for the scapula axis and the intermediate glenoid line with excellent intra observer reliability (ICC > 0.957) and inter-observer reliability (ICC=0.954).

Conclusion: Measurement of glenoid version on axial cut of a Ct-scan is highly reliable. Significant differences exist between measures depending which method is used, underlying the importance of a consensus for research and clinical purpose. Despite very good performance of all methods, authors recommend the use of the Friedman method for the scapula axis reference and an intermediate glenoid line in case of B2 glenoid.

Purpose: The long term effects of treatment in a cohort of patients with chronic low back pain (CLBP) participating in an intensive pain management program.

Background: Cognitive behavioral treatments produce clinically relevant benefits for patients with CLBP.

Methods: The program provided by RealHealth-Netherlands is based on cognitive behavioral principles and executed in collaboration with orthopedic surgeons. Primary outcomes were daily functioning and self-efficacy. Measurements were at baseline, last day of residential program and at 1 and 12 months follow-up. A GLM procedure with repeated measures was applied to examine changes over time and to explore possible unwanted side effects. Effect sizes are analyzed using cohen’s d. Clinical relevance was examined using minimal clinical important differences (MCID) estimates for primary outcomes and quality of life. To compare results with literature Standardized Morbidity Ratios (SMR) were determined.

Results: 107 patients with CLBP participated. Mean scores on primary and secondary outcomes showed a similar pattern: improvement immediately after following the program and maintenance of results over time. Effect sizes were 0.9 for functioning and 0.8 for self-efficacy. Clinical relevancy: 79% reached MCID on functioning, 53% on self-efficacy and 80% on quality of life. Found study results were 36% better and 2% worse when related to previous research on respectively rehabilitation programs and spinal surgery for similar conditions (SMR 136% and 98%respectively).

Conclusion: The participants of this evidence based program learned to manage CLBP, improved in daily functioning and quality of life. The study results are comparable with results of spinal surgery and even better than results from less intensive rehabilitation programs.

Conflict of Interest: None

Sources of Funding: None

Purpose: The glenoid status is a crucial aspect of planning for shoulder replacements. This study revisits the classification proposed by Walch et al and discusses its value to orthopedic surgeons in terms of reproducibility and reliability.

Method: Three evaluators viewed one hundred-sixteen (116) shoulder CT-scans with primary glenohumeral arthritis and classified glenoid wear according to Walch classification two times. The validation study was done for three sets of data: Set I: the complete classification: A1, A2, B1, B2, C. Set II: regrouping with main categories: A,B,C. Set III: regrouping categories according to glenoid facet morphology; Normal concavity: A1, A2, B1; Biconcave glenoid: B2; Retroverted glenoid: C.

Results: Intra-observer Kappa values for Observer 1, 2, and 3 averaged 0.866 (0.899, 0.927, 0.773) for Set I; for Set II, the values averaged 0.915 (0.955, 0.975, 0.814); and for Set III, the values averaged 0.874 (0.897, 0.948, 0.777), all excellent values. Inter-observer reliability values for Set I averaged 0.621 (0.776, 0.512, 0.574), indicating good agreement; for Set II, the values averaged 0.759 (0.880, 0.713, 0.685), indicating excellent inter-observer agreement; and for Set III, the average was 0.642 (0.825, 0.519, 0.581), indicating good inter-observer agreement.

Conclusion: A clarification of the Walch et al classification of the osteoarthritic glenoid was necessary, especially with regards to the wordings of categories B2 and C. When used properly, it is a reliable and valuable tool for orthopedic surgeons of all levels of experience in the evaluation of the osteoarthritic glenohumeral joint.

Purpose of the study: The risk of homologous blood transfusion for primary total knee arthroplasty (TKA) varies between centres from 4 to 72%. Measurement of mean blood loss for patients undergoing primary total hip or knee arthroplasty led us to adopt a global blood-sparing protocol.

Material and methods: This was a prospective observational study involving 90 TKA (TC-SB) implanted by one surgeon in 56 women and 33 men, mean age 74 years, ASA 3 for 29%, mean BMI=31. Programmed autologous transfusion and blood recovery were not applied. Alpha epoeitine (EPO was administered in the preoperative period in accordance with the predicted serum haemoglobin at discharge. Tranexamic acid (TA) was injected intravenously during the operation.

Results: The mean operative time was 63 minutes, mean tourniquet time 51 minutes. During the perioperatively period, the mean 7-day blood loss was 566±254 ml red cells and 1560±643 total blood. Mean serum haemoglobin at discharge was 1.0 g/dl. Fourteen percent of patients had a postoperative serum haemoglobin less than 10 g/dl (lowest level 8.4 g/dl). One patient had a transfusion; this was a man in his nineties who was operated on without a tourniquet and without TA because of a poor arterial system. Nearly 86% of patients received TA with a significant (p< 0.05) decrease in bleeding compared with those who did not receive TA (365 ml total blood). EPO was delivered for 22% of patients (2.8 injections on average) to reached 14.2 g/dl the day before the operation.

Discussion: This overall strategy for blood sparing enabled us to reduce the risk of transfusion and limit costs. In this series, the prescription of EPO was not targeted to reach a set level preoperatively but was based on the predicted serum haemoglobin level at discharge. Thus seven patients with a preoperative haematocrit below 39 did not receive EPO. None of these patients were transfused. Their discharge haemoglobin was between 10.7 and 12.4g/dl. Use of TA should be included in the calculation of the predicted discharge haemoglobin level in order to better determine candidates for EPO injections.

Introduction: Primary bones sarcomas account for 5% of childhood cancers; however the introduction of neo-adjuvant chemotherapy and the development of surgical techniques have resulted in reduced mortality and a longer length of survival. Consequently improving post operative functional outcomes has become an important focus of research. The aim of this study was to investigate and compare differences in the complications and functional outcomes of EPR and rotationplasty in skeletally immature patients.

Methods: This is a retrospective case control study of twenty-four patients, of whom twelve received rotation-plasty and twelve received EPR. Patients were selected at random and matched according to age at diagnosis, sex, site of disease and date of surgery. The Musculoskeletal Tumour Society (MSTS) score was used to evaluate functional outcome, and surgical complications were assessed qualitatively.

Results: Five patients (42%) treated with endoprosthe-ses experienced some form of post-operative surgical complication compared to three patients (25%) treated with rotationplasty. However this difference was not found to be statistically significant. The average MSTS score in the EPR cohort was 22.7 and 18.9 in rotation-plasty patients. Mann Whitney U testing confirmed this difference to be statistically significant (p=0.05).

Discussion: The study showed that patients who received EPR suffered more surgical complications than rotationplasty patients. However the results demonstrated superior functional outcomes in patients who received EPR.

The theoretical benefit historically attributed to rota-tionplasty lies in the provision of a functional and durable hinge joint, however these results suggest that this advantage has been negated by modern endoprostheses, probably due to improvements in surgical experience and prosthesis technology.

Conclusion: Our experience shows that patients with EPR are more likely to suffer more surgical complications but have similar, if not better functional outcomes compared to rotationplasty.

Introduction: Since January 2008 a large set of parameters of each hip fracture patient admitted to the RdGG hospital, were documented prospectively. This documentation was repeated by a written survey 3 months and 1 year after the fracture.

Our research goal was to determine the percentage of patients returning to their living situation prior to their fracture.

Methods: From 1-1-2008 to 1-3-2009, 339 hip fracture patients were treated, 244 female, 95 male. Average age was 78.1 (21–101). ASA distribution showed 240 ASA I/ II patients and 99 ASA III/IV patients. Conservative treatment was chosen in 7 patients, 213 were treated with an osteosynthesis and 117 with a (hemi)-arthroplasty. All patients received a survey regarding their living situation 3 and 12 months after their hip fracture.

Results: 327 patients could be analyzed as the pre fracture living situation of 12 patients was unknown; 71% lived independently, 21% in a care home and 9% in a nursing home. The follow-up (FU) of the living situation of the first two groups was analyzed.

Patients living independently: 45% was discharged directly to their own home, 24% to a nursing home and 3% to a care home. A special rehabilitation unit within our hospital, the “Herstel Unit”, received 28% of patients for further recovery. Patients could rehabilitate here for a maximum of 4 weeks before going home. After 3 months 84% of the patients had returned to their independent living situation, 11% lived in a nursing home and 5% in a care home. This analysis is done in 184 patients as 12 had died and 35 were lost to FU. After 12 months 38 (84%) of 45 still lived independently, 4 went to a nursing home, 3 to a care home, 21 died and 4 were lost to FU.

Care home patients: 47% was discharged directly to their care home, 15% to the “Herstel Unit” and 37% to a nursing home. At 3 months 69% of the patients had returned to their care home, 31% lived in a nursing home. Analysis is done in 45 patients as 15 had died and 8 were lost to FU. 12 months FU is accomplished in 27 patients of whom 19 died, none lost to FU; 88% lived in a care home, 12% in a nursing home.

Conclusions: More than 80% of the pre operative independently living patients have returned to their own independent living situation within 3 months. At 1 year FU this percentage is steady. 52% of this population stayed briefly on an alternative location for further recovery. The patients living in a care home have stayed longer on an alternative location, but more than 90% of them have returned to their pre fracture living situation at 12 months FU.

Our results challenge the prejudice that hip fracture patients live or end up living in a nursing home. These data can be used to calculate the amount of specific discharge locations needed in the near future.

Press-fit cups have given excellent clinico-radiographical results. This is a retrospective clinico-radiographical study about the long term performance of pure Titanium cementless modular press-fit cups (FitekTM) having, on the outer surface, an oriented multilayer titanium mesh (SulmeshTM) with 65% porosity (average pore size=400–640 micron). The cup was implanted after underreaming the acetabulum by 2 mm. In the cup’s equatorial area there are two “fins” originary designed to improve rotational stability but actually representing two excellent primary mechanical stabilizers.

We have evaluated the first 100 consecutive cups implanted in 92 patients with an average FU of 9,7 years (range 9–11 years). All operations have ben performed by the two Senior Authors (PGM and RB). Regarding etiology, we had 43 Primary Arthritis, 37 Dysplastic Arthritis, 12 Osteonecrosis and 8 Post-traumatic Arthritis. results were evaluated with the Harris score. Radiographic evaluation was performed using AP and lateral x-rays pre-op. post-op and at the last follow-up.

We had 86 Excellent, 10 Good, 2 Fair and 2 Poor. The 2 Poor results were 2 aseptic loosenings of the stem

The Mann-Whitney nonparametric U test and the Kruskal-Wallis test showed that the survival rate of the 100 analyzed cups, after a mean follow-up of 9.7 years, was 100% (end point: revision for any cause)

Etiology was not statistically correlated with post-op score.

Nevertheless, dysplastic patients showed inferior results compared to arthritic patients in different parameters, as pain, limp, Range Of Motion (p < 0.05), putting socks and shoes (p < 0.05).

Our cups were intentionally implanted and radiographically appear in a fairly horizontal position (36.5° on average).

In 6 cases we could calculate an eccentricity of the metal heads proving bidimensional linear wear of the liner (average 0.265 mm / year). At the last follow-up we had 3 femoral osteolysis, while in the acetabular side radiolucent lines were present in 14 % of the cases, never progressive.

In no case we found a change of position of the cup.

FitekTM cementless cups gave excellent results at 10 years with complete stability and osteo-integration. Excellent primary mechanical stability was given by the rough surface (SulmeshTM) and by the two “fins” in the equatorial area.

Reconstruction following internal hemipelvectomy for bone tumors remains a major surgical challenge. Most of the cases are considered not suitable for reconstruction because of high complication occurrence. Allografts coupled with standard prosthesis is a reliable method of reconstruction.

26 patients received a McMinn stemmed cup (Link, Germany) after periacetabular tumor resection from February 1999 to 2006. In 18 patients the reconstruction followed resection of the acetabular area while in other 8 an extrarticular resection of the proximal femur was performed. In 21 cases a stemmed acetabular cup were associated with massive bone allograft. There were 13 female and 13 male with a mean age of 41 years (13 to 70). Average follow-up was 45 months (7 to 105).

Six patients were affected by local recurrence of the tumour and five underwent hindquarter amputation. In 4 of them the index surgery followed a previous recurrence of the tumour. Finally 6 patients died for related causes within 2 years. All the other 20 have been followed clinically and radiographically for a minimum of 24 months.

Deep infection occurred in one case, there were no cases of dislocation. Radiolucency at the prosthesis-bone interface was observed in 3 cases, 2 patients had proximal migration < of 20 mm. Only one patient was treated for aseptic loosening because of incorrect initial position of the implant. The iliac osteotomy was consolidated in all cases, while a delayed union was frequently observed in the pubic osteotomy, however without compromise the stability of implant. Functional result were evaluated according to the MSTS system and this showed 65% of excellent or good clinical results.

The procedure requires appropriate patient selection, accurate preoperative planning, meticulous selection and preparation of allograft. Usually artificial ligaments are applied to reduce hip instability, however, this type of reconstruction do not require complex fixation, thus reducing surgical time and early complications.

Synovial sarcoma (SS) is rare but increasingly diagnosed and associated with poor prognosis. Primary surgical resection with wide margins and adjuvant radiation-therapy is considered gold standard in treatment of primary SS. Although (Neo)adjuvant chemo- and radiationtherapy are used in the primary treatment of SS, they are not advocated outside a clinical trial setting. In patients with primary SS and pulmonary metastases, (neo)adjuvant chemotherapy is often added to the treatment protocol but it’s effect on overall survival seems limited.

Between 1985 and 2004 33 patients with primary SS were treated in our clinic. Seventeen patients were diagnosed with pulmonary metastases at presentation (9) or during postoperative follow-up (8). Wide resection or focally marginal resection followed by radiotherapy was used as primary treatment for all patients. All primary metastasized patients were treated with adjuvant multi-agent chemotherapy including Isofosfamide. Average survival in this group was 32 months (5 year OS 50%), compared to 60 months in the late metastasized patient-group (2 and 5 year OS 50 and 11%). Wide resection was not related to improved overall survival when compared to marginal margins and additional radiation therapy. In the early metastasized group combined chemo-radiaton therapy provided no significant improvement in overall survival over adjuvant chemotherapy or radiation therapy alone. However additional chemotherapy in the late metastasized group was slightly associated with increased overall survival (5 year OS 0% vs 66%).

Treatment of early pulmonary metastasized SS remains highly dependent of the individual preference of patient and physician. In contrast to the reported prolonged disease free/overall survival of Enneking stage IIA and IIB SS patients, aggressive surgical and chemo-radiation therapy has not yet been associated with improvement of disease free/overall survival in stage III disease. Patients presenting with late pulmonary metastasis might benefit from adjuvant multi-agent chemotherapy treatment.

Introduction: The management atlanto-axial fractures, particularly those of the odontoid peg, remains controversial. We managed patients with C1/C2 fractures non-operatively in rigid immobilization until CT-scanning confirmed bony union, rather than for the standard 3-month period. We examined whether this improved outcomes and reduced the need for surgery.

Method: All patients admitted to our unit with atlanto-axial fractures between 2001–2007 were retrospectively analyzed. All fractures had the ‘intention-to-treat’ conservatively in either halothoracic vest (85%) or Aspen collar (15%). Rigid immobilization was maintained until CT-scanning demonstrated bony fusion. Functional stability was subsequently assessed with flexion-extension radiographs after removal of rigid immobilization.

Results: Twenty-seven patients were studied. Nineteen had odontoid peg fractures (10 type II; 9 type III). The remainder consisted of 3 Hangman’s, 3 lateral mass and 2 atlas ring fractures. 83% of patients progressed to union at an average of 13.2 weeks (range 5–22). Six complications related to halo immobilization were observed (three skull perforations/pin-site infections). All of these patients progressed to union non-operatively.

Failure of non-operative management was deemed as non-union or poor patient tolerance of halo, and occurred in 4 patients (17%). All four had type II odontoid peg fractures, and had transarticular screw fixation. One postoperative complication of screw fracture was recorded.

Conclusion: Non-union rates of conservatively managed atlanto-axial fractures with standard 3-month rigid immobilization have been reported as high as 35%. In our series, CT-imaging to confirm bony union prior to removal of the rigid immobilization (prolonging immobilization where necessary) significantly lowered the rate of non-union and therefore the need for subsequent surgery.

Ethics approval: None Audit

Interest Statement: None

Detection of local recurrence after sarcoma resection can be impaired by metal implants locally, or by the patient ‘s general condition. Metal implants cause severe distortion and scattering of either MRI or CT data acquisition. Therefore the detection of local recurrences in proximity of heavy metal implants such as prostheses or osteosynthesis material can be difficult. Patient related conditions, e.g. renal insufficiency, allergy, claustrophobia, may completely prohibit the use of contrast media or even a scan itself.

Ultrasound provides several advantages, and can be used for different indications in sarcoma patients. Patient related conditions prove no obstacle for this technique. Currently our indications are local follow-up after soft-tissue sarcoma resection and evaluation of regional lymph nodes, detection of local recurrence of bone sarcoma in proximity of metal implants, and amputation stump evaluation.

We describe a patient study population of 103 patients. Seventeen had only diagnostic and staging ultrasound, four had an evaluation of their amputation stump, 24 were followed after resection of a soft-tissue sarcoma, and 58 were followed by this method after sarcoma resection and implantation of metallic implants. Evaluation modalities are described according to the indications.

Results: We have detected nine local recurrences, and four patients with suspect lymph nodes had a biopsy of which half showed malignant tumour cells. Infection and inflammation around metallic implants can be evaluated, the technique also allowing placement of drains in infected seromas in irradiated regions. It should be emphasised that reliable results can only be achieved if a baseline ultrasound is performed, followed by subsequent studies at regular intervals.

Little is published about the use of cementless conical stems in primary hip arthroplasty for congenital hip disease. A conical stem was designed in the 80’s by Prof. Wagner. The stem is made of a rough blasted titanium alloy with a cone angle of 5° and 8 sharp longitudinal “ribs” that cut into the inner cortex, designed to achieve rotational stability: The ribs depth of penetration ranges between 0.1 and 0.5 mm and is also very important to achieve osteo-integration. The CCD angle is 135°. The stem is straight and can be implanted in any degree of version thus being very useful for dysplastic arthritis with significant femoral neck anteversion.

Between 1993 and 1998 the senior author (RB) implanted 92 conical stems in 88 consecutive patients with dysplastic arthritis. The acetabular component was cementless and titanium with tridimensional porosity. The articulating surface was a second generation Metal-on-Metal.with a femoral head of 28 mm. According to the Hartofilakidis classification 63 patients had type A, 18 type B and 11 type C.

The average follow-up was 11.2 years (range 10.1–14.8)

Using the Harris Hip Scoring system we had 82 (89%) satisfactory results, with excellent correction of pre-op pain (42/44 Harris) and no case of anterior thigh pain; 88% of patients had no or slight limp at follow-up. No patient required revision of the stem, but one cup required revision for loosening (Type C class). We had one dislocation (1%) that was treated conservatively

Radiographically, all stems were osteo-integrated, 17% showed some resorption in femoral zone 1 and 7. In the same zones we observed 4 cases of real osteolysis without loosening. No radiolucent line was observed in other femoral zones. In the acetabular side we had 13 cases (14%) of radiolucency, but in only 1 case (1%) was it progressive.

A straight conical titanium femoral stem gave very satisfactory clinico-radiographical results in dysplastic arthritis at a mean of 11.2 years of follow-up.

Multi-ligament knee injuries require complex surgery. Hinged external fixators propose to control the tibio-femoral relationship, protect reconstructions and allow early mobilisation. However, a uniaxial hinge may be too simplistic for such a complex joint. We investigated the influence of an external fixation device on ligament strains and joint contact forces.

Six fresh frozen cadaveric lower limbs (41–56 years old) were obtained. Displacement transducers (Microstrain, USA) were attached to mid-substance lateral (LCL) and medial collateral (MCL) ligaments, and the anterior and posterior cruciate (PCL) ligaments through minimal soft tissue incisions. Joint pressures were measured by transducers (Tekscan) introduced in the medial and lateral compartments through small sub-meniscal arthrotomies. Flouroscopic imaging was used to construct the hinged fixator centred over the epicondylar axis. Ligament tensile strains and joint contact forces were determined through a passive arc of 20 to 110 degrees of flexion and extension, with and without the external fixator (ExFix^™, EBI Biomet Australia).

The application of the external fixation device resulted in minimal change in the mean peak percentage strain of the PCL, MCL and ACL ligaments, while the LCL peak percentage strain decreased. Generally the peak percentage strain for each ligament occurred at or near the same flexion angle in both the un-instrumented and instrumented case within each limb, but the peak percentage strain flexion angles varied significantly across limbs. Peak joint contact forces increased significantly (p < 0.05) in the lateral compartment after attachment of the external fixation device. There was no difference seen in the medial compartment joint contact forces.

This study shows that a uniaxial hinged external fixator can be used in a multi-ligament reconstructed knee to maintain joint congruence and allow early postoperative rang of motion without compromising the results of reconstructions or repairs.

Introduction: Both enchondromas and chondrosarcomas are mesenchymal neoplasms which originate from cartilage cells, and they occur mainly in the extremities. Both these tumours are resistant to chemotherapy and radiotherapy, and surgery is the only treatment option. In the last few years limb saving procedures have become the treatment of choice. Intra-operative cryosurgery has been introduced as a local adjuvant therapy for skeletal benign and low-grade malignant tumours. It is applied after curettage of the lesion to destroy any remaining tumour cells, and to enlarge the oncological margin of resection. Since the introduction of cryosurgery as an adjuvans, oncological and functional results of this extremity sparing surgery are significantly enhanced.

Patients and Methods: A retrospective study was conducted to evaluate the oncological and functional results, and the complications of cryosurgical treatment.

Data were prospectively collected from the tumour register and patient records. Functional scores of the affected limbs were assessed according to the Musculo-Skeletal Tumour Society scoring system.

Results: Between 1994 and 2003 123 patients (47 men, 76 women, average age 49 years; range 13–83 yrs) were treated with curettage and cryosurgery for an Enneking stage 3 enchondroma (75 patients) or a low-grade chondrosarcoma (55 patients).

The minimal follow up was two years, and the average follow up 50 months (range 24–119 months).

At follow up three recurrences had occurred in patients treated for enchondroma. One residual tumour was diagnosed in a patient with chondrosarcoma grade Ib. All patients were treated again with curettage and cryosurgery and disease free at the latest follow-up.

Of the 37 complications the most common were a fracture at the surgical site (18), fracture of osteosynthesis (6), 3 wound infection (3), delayed soft tissue healing (3), and transient nerve palsy (3).

Functional MSTS scores increased in time to an average of 28 points (94%) at two year follow up. No significant difference in scores were found regarding to localisation of the lesion, age or gender. A significant discrepancy in functional scores was observed between patients who did suffer from one or more complications and patients who did not.

Conclusion: We believe that the use of cryosurgery is an excellent adjuvant therapy after curettage to achieve local control of aggressive enchondromas and low grade chondrosarcomas. It avoids the need for segmental resection, making reconstruction of the bony defect easier and therefore results in excellent functional outcome. Due to the initial high fracture rate osteosynthesis at the surgical site is used more often, and weight baring mobilisation is postponed until full consolidation is reached.