With the rising rates, and associated costs, of total knee arthroplasty (TKA), enhanced clarity regarding patient appropriateness for TKA is warranted. Towards addressing this gap, we elucidated in qualitative research that surgeons and osteoarthritis (OA) patients considered TKA need, readiness/willingness, health status, and expectations of TKA most important in determining patient appropriateness for TKA. The current study evaluated the predictive validity of pre-TKA measures of these appropriateness domains for attainment of a good TKA outcome.

This prospective cohort study recruited knee OA patients aged 30+ years referred for TKA at two hip/knee surgery centers in Alberta, Canada. Those receiving primary, unilateral TKA completed questionnaires pre-TKA assessing TKA need (WOMAC-pain, ICOAP-pain, NRS-pain, KOOS-physical function, Perceived Arthritis Coping Efficacy, prior OA treatment), TKA readiness/willingness (Patient Acceptable Symptom State (PASS), willingness to undergo TKA), health status (PHQ-8, BMI, MSK and non-MSK comorbidities), TKA expectations (HSS KR Expectations survey items) and contextual factors (e.g., age, gender, employment status). One-year post-TKA, we assessed for a ‘good outcome’ (yes/no), defined as improved knee symptoms (OARSI-OMERACT responder criteria) AND overall satisfaction with TKA results. Multiple logistic regression, stepwise variable selection, and best possible subsets regression was used to identify the model with the smallest number of independent variables and greatest discriminant validity for our outcome. Receiver Operating Characteristic (ROC) curves were generated to compare the discriminative ability of each appropriateness domain based on the ‘area under the ROC curve’ (AUC). Multivariable robust Poisson regression was used to assess the relationship of the variables to achievement of a good outcome.

f 1,275 TKA recipients, 1,053 (82.6%) had complete data for analyses (mean age 66.9 years [SD 8.8]; 58.6% female). Mean WOMAC pain and KOOS-PS scores were 11.5/20 (SD 3.5) and 52.8/100 (SD 17.1), respectively. 78.1% (95% CI 75.4–80.5%) achieved a good outcome. Stepwise variable selection identified optimal discrimination was achieved with 13 variables. The three best 13-variable models included measures of TKA need (WOMAC pain, KOOS-PS), readiness/willingness (PASS, TKA willingness), health status (PHQ-8, troublesome hips, contralateral knee, low back), TKA expectations (the importance of improved psychological well-being, ability to go up stairs, kneel, and participate in recreational activities as TKA outcomes), and patient age. Model discrimination was fair for TKA need (AUC 0.68, 95% CI 0.63-0.72), TKA readiness/willingness (AUC 0.61, 95% CI 0.57-0.65), health status (AUC 0.59, 95% CI 0.54-0.63) and TKA expectations (AUC 0.58, 95% CI 0.54-0.62), but the model with all appropriateness variables had good discrimination (AUC 0.72, 95% CI 0.685-0.76). The likelihood of achieving a good outcome was significantly higher for those with greater knee pain, disability, unacceptable knee symptoms, definite willingness to undergo TKA, less depression who considered improved ability to perform recreational activities or climb stairs ‘very important’ TKA outcomes, and lower in those who considered it important that TKA improve psychological wellbeing or ability to kneel.

Beyond surgical need (OA symptoms) and health status, assessment of patients’ readiness and willingness to undergo, and their expectations for, TKA, should be incorporated into assessment of patient appropriateness for surgery.

The aim of this study was to determine the incidence, annual trend, perioperative outcomes, and identify risk factors of early-onset (≤ 90 days) deep surgical site infection (SSI) following primary total knee arthroplasty (TKA) for osteoarthritis. Risk factors for early-onset deep SSI were assessed.

We performed a retrospective population-based cohort study using prospectively collected patient-level data from several provincial administrative data repositories between January 2013, and March 2020. The diagnosis of early-onset deep SSI was based on published Centre for Disease Control/National Healthcare Safety Network (CDC/NHSN) definitions. The Mann-Kendall Trend Test was used to detect monotonic trends in early-onset deep SSI rates over time. The effects of various patient and surgical risk factors for early-onset deep SSI were analyzed using multiple logistic regression. Secondary outcomes were 90-day mortality and 90-day readmission.

A total of 20,580 patients underwent primary TKA for osteoarthritis. Forty patients had a confirmed deep SSI within 90-days of surgery representing a cumulative incidence of 0.19%. The annual infection rate did not change over the 7-year study period (p = 0.879). Risk factors associated with early-onset deep SSI included blood transfusions (OR, 3.93 [95% CI 1.34-9.20]; p=0.004), drug or alcohol abuse (OR, 4.91 [95% CI 1.85-10.93]; p<0.001), and surgeon volume less than 30 TKA per year (OR, 4.45 [1.07-12.43]; p=0.013). Early-onset deep SSI was not associated with 90-days mortality (OR, 11.68 [0.09-90-58]; p=0.217), but was associated with an increased chance of 90-day readmission (OR, 50.78 [26.47-102.02]; p<0.001).

This study establishes a reliable baseline infection rate for early-onset deep SSI after TKA for osteoarthritis through the use of a robust methodological process. Several risk factors for early-onset deep SSI are potentially modifiable or can be optimized prior to surgery and be effective in reducing the incidence of early-onset SSI. This could guide the formulation of provincial screening programs and identify patients at high risk for SSI.

There has been growing interest in the literature regarding evaluation of functional outcomes in patients undergoing total knee arthroplasty (TKA) and total hip arthroplasty (THA) while suffering from depression and using selective serotonin reuptake inhibitors (SSRI). Previous literature has shown that these patients have lower post-operative functional scores compared to those without SSRI use and with multiple musculoskeletal co-morbidities. This might be the result of potentially suboptimal motivation and participation in the post-operative rehabilitation programs. One recent study from a single center has suggested a reduction in adverse events in patients undergoing arthroplasty while on SSRI. The purpose of this study is to evaluate the post operative functional scores of patients on SSRI and compare them with the patients not prescribed SSRIs.

A retrospective data analysis was performed on patients who had primary TKA and primary THA between 1st June 2014 and 31st May 2017. The patients into two groups. In the first, patients received SSRI for at least one year before the surgery while in group two, patients did not receive SSRI. Outcome measures included Western Ontario and McMaster university osteoarthritis index (WOMAC) and EQ5D5L scores at pre surgery, three months and 12 months post surgery.

Chi-square and t test was used to compare categorical variables and continuous variables respectively. Multivariate linear regression was conducted to compare the change of scores between the two groups and was adjusted for age, gender, and comorbidities. These outcome scores were analyzed separately for TKA and THA.

In the TKA group, there were 1,452 patients using SSRI and 15,981 not using SSR. In the THA group there were 851 patients using SSRIs and 10,102 patients without SSRIs. The baseline WOMAC for TKA patients was 45.6 for the controls and 41.8 for those patients on SSRIs (p < 0 .001). The baseline EQ5DL was 0.53 and 0.46 in the same groups (p < 0 .001). The baseline WOMAC for THA patients was 39.1 for the controls and 36.2 for patients using SSRIs (p < 0 .001). The baseline EQ5DL scores were 0.43 and 0.37respectively, again indicating patients on SSRI therapy had lower baseline scores (p < 0 .001).

There was improvement in WOMAC and EQ5DL scores in all patient groups at 3 months and 12 months. After adjusting for gender, age, comorbidities and baseline score, THA patients not using SSRI showed a greater improvement in their WOMAC and EQ5DL scores than those prescribed SSRIs, WOMAC (p=0.008), EQ5DL (p=0.001). TKA patients showed a similar outcome but only the EQ5DL was statistically significant, WOMAC (p=0.12), EQ5DL (p=0.036).

Our results show that patients on SSRI have lower preoperative WOMAC and EQ5DL scores at baseline when compared to patients not undergoing treatment for depression or anxiety with SSRIs. After arthroplasty, patients using SSRIs show significant improvement at 12 months but the improvement is smaller than the group not using SSRIs.

Osteoarthritis (OA) is the fastest growing global health problem, with a total joint replacement being the only effective treatment for patients with end stage OA. Many groups are examining the use of bone marrow or adipose derived mesenchymal stem cells (MSCs) to repair cartilage, or modulate inflammation to promote healing, however, little efficacy in promoting cartilage repair, or reducing patient symptoms over temporary treatments such as micro-fracture has been observed. There is a growing body of literature demonstrating that MSCs derived from the synovial lining of the joint are superior in terms of chondrogenic differentiation and while improvements in clinical outcome measures have been observed with synovial MSCs, results from clinical studies are still highly variable.

Based on our results, we believe this variability in clinical studies with MSCs results in part from the isolation, expansion and re-injection of distinct MSCs subtypes in normal vs. OA tissues, each with differing regenerating potential. However, it remains unknown if this heterogeneity is natural (e.g. multiple MSC subtypes present) or if MSCs are influenced by factors in vivo (disease state/stage). Therefore, in this study, we undertook an ‘omics’ screening approach on MSCs from normal and OA knee synovial tissue. Specifically, we characterized their global proteome and genomic expression patterns to determine if multiple MSC from normal and OA joints are distinct at the protein/gene expression level and/if so, what proteins/genes are differentially expressed between MSCs derived from normal and OA synovial tissue.

Synovium tissue was collected from OA patients undergoing joint replacement and normal cadaveric knees. The in vitro adipogenic, chondrogenic and osteogenic differentiation potential of the MSCs was analyzed via qPCR and histology. Fully characterized MSC populations where then analyzed through an unbiased shotgun proteomics, and microarray analysis.

Synovial MSCs isolated from both OA and normal knees demonstrated similar multipotent differentiation capacity. Likewise, both OA and normal MSCs display the typical MSCs cell surface marker profile in vitro (CD90+, CD44+, CD73+, CD105+).

Using shotgun proteomics, 7720 unique peptides corresponding to 2183 proteins were identified and quantified between normal and OA MSCs. Of these 2183 proteins, 994 were equally expressed in normal and OA, MSCs, 324 were upregulated in OA MSCs (with 50 proteins exclusively expressed in OA MSCs), 630 proteins were upregulated in normal MSCs (with 16 proteins exclusively expressed in normal MSCs). Microarray analysis of normal and OA MSCs demonstrated a similar result in where, 967 genes were differentially expressed between normal and OA MSCs, with 423 genes upregulated in OA, and 544 genes upregulated in normal MSCs.

In this project, we have demonstrated that although normal and OA synovial derived MSCs demonstrate similar multipotent differentiation potential and cell surface markers expression, these cells demonstrated significant differences at the molecular level (protein and gene expression). Further research is required to determine if these differences influence functional differences in vitro and/or in vivo and what drives this dramatic change in the regulatory pathways within normal vs. OA synovial MSCs.

Background

One of the potential complications of polyethylene liner (PL) is its dissociation from the metal shell. This is a rare but catastrophic complication of total hip replacement (THR).

Despite recent advances in the management of slipped capital femoral epiphysis (SCFE), controversy remains about the treatment of choice for unstable slips. Surgical dislocation and open reduction has the advantage of identifying and preserving the blood supply of femoral head thereby potentially reducing the risk of avascular necrosis, (AVN). There is large variation in the literature from several small series about reported AVN rates ranging from two to 66% for unstable SCFE treated with surgical dislocation. The aim of our study was to analyze our experience with acute open reduction and internal fixation of unstable acute and unstable acute on chronic slips using the technique of surgical dislocation described by Professor Reinhold Ganz.

A retrospective review of 11 patients (12 hips) treated by surgical dislocation, reduction and pinning as the primary procedure for unstable acute and unstable acute on chronic SCFE in a tertiary referral children's hospital was undertaken. This represents the entire series treated in this manner from September 2007 to January 2018. These procedures were performed by a team of Orthopaedic surgeons with significant experience performing surgical dislocation of the hip including patients with chronic SCFE, Perthes' disease, impingement and acetabular fractures. Demographic data, intraoperative records, postoperative notes and radiographs including details of subsequent surgery were reviewed.

There were seven boys and four girls with mean age of 13.4 years, range 11 to 15 years at the time of surgical dislocation. Out of 12 hips, two had acute unstable slip while the remaining 10 had acute on chronic unstable slip. Six patients had good or excellent results. The remaining six patients developed AVN of which three patients had total hip replacement at six months, 17 months and 18 months following primary procedure. Seven patients required more than one operation. Three patients lost their correction and required re fixation despite surgical dislocation, reduction and fixation being their primary procedure.

This series demonstrates a high percentage of AVN (50%) in severe unstable SCFE treated with surgical dislocation despite careful attention to retinacular flap development and intra operative doppler studies. This is in direct contrast to our experience with subcapital reorientation with surgical dislocation in stable slips where excellent results were achieved with a low rate of AVN. Pre-operative imaging with MRI and perfusion studies may identify where ischemia has occurred and might influence operative treatment. Based on our results, we do not recommend routine use of surgical dislocation in unstable SCFE. This technique requires further scrutiny to define the operative indications in unstable SCFE.

Aims

Dislocation is the most common indication for further surgery following total hip arthroplasty (THA) when undertaken in patients with a femoral neck fracture. This study aimed to assess the complication rates of THA with dual mobility components (THA-DMC) following a femoral neck fracture and to compare outcomes between THA-DMC, conventional THA, and hemiarthroplasty (HA).

Aim

This study aimed to evaluate the impact on length of hospital stay from dedicated infectious diseases input for orthopaedic infection patients compared to sporadic infection specialist input.

There is currently no cure for osteoarthritis (OA), although there are ways to manage it, but most require quite invasive surgeries. There is a resident mesenchymal progenitor cell (MPC) population within the synovial membrane of the joint that have the ability to differentiate into bone, fat, and cartilage. We hypothesise that in vivo and in vitro cell surface marker expression comparisons of the MPCs can determine which population has the highest chondrogenic capacity and is best suited for future clinical trials.

Method optimisation protocol: Synovial biopsies (2 or 5mm) were obtained from patients undergoing surgery. The biopsies were digested in either collagenase type I, IA, IV or II at a concentration of 0.5 or 1.0 mg/mL. Digestion was conducted at 37°C for 30, 60, 90 or 120min. To assay for the number of MPCs obtained, the cell suspension was stained with CD90 (a synovial MPC marker) and magnetically purified. The purified cells were then assayed by flow cytometry (Co-stained with a live/dead cell marker, BV510) or bright-field microscopy. Study protocol: Synovial tissues were digested in type IV collagenase for two hours to obtain a single cell suspension. The cells were subsequently stained with mesenchymal stem cell markers, including CD 90, CD 271, CD 44, CD73, and CD105, a macrophage marker, CD68. The macrophages were excluded and the remaining cells were index sorted into 96-well plates. The cells were expanded, and underwent 21-day chondrogenic, adipogenic, and osteogenic differentiation. Differentiation was assayed using RT-qPCR and histological methods. Additionally, the cells were re-analysed for marker expression after culturing.

Optimisation: Synovial biopsies of 5mm produced a greater number of live CD90+ cells than 2mm biopsies. It was observed that type IV collagenase at 1mg/ML treatment for 120 min (hip) and 90 min (knee) obtained the greatest number of CD90+ MPCs from the synovium. Results: A single cell was isolated from an OA hip biopsy and was positive for the markers CD90, CD44, CD73, and negative for the markers CD68, CD271, CD105. Following differentiation, PCR analysis suggested that the cell line was able to differentiate into chondrocytes and adipocytes, but not osteoblasts. Histology data agreed with the PCR data with the adipocytes and chondrocytes having positive staining, whereas the osteoblasts were negative. FACS analysis following proliferation showed that the expression in vivo versus in vitro was the same except CD105 that became positive after proliferation in vitro.

MPCs express cell surface markers that provide information as to populations have the best cartilage regeneration abilities. By determining the properties of the MPCs in OA hips that allow for better chondrogenic differentiation abilities in vitro, selecting the optimal cells for regenerating cartilage can be done more efficiently for novel cell therapies for OA.

To identify the differences in inflammatory profiles between hip OA, knee OA and non-OA control cohorts and investigate the association between cytokine expression and clinical outcome measurements, specifically pain.

A total of 250 individuals were recruited in three cohorts (100 knee OA, 50 hip OA, 100 control). Serum was collected and inflammatory profiles analysed using the Multiplex Human Cytokine Panel (Millipore) on the Luminex 100 platform (Luminex Corp., Austin, TX). The pain, physical function and activity limitations of hip OA cohort were scored using the WOMAC, SF-36, HHS and UCLA scores. All cytokine levels were compared between cohorts individually using Mann–Whitney–Wilcoxon (MWW) test with Bonferroni multiple comparison correction. Within hip OA cohorts, the effect of hip alignment (impingement and dysplasia) and radiographic grade (Kellgren and Lawrence grade, K/L grade) on cytokine levels were accessed by MWW test. Spearman's rank correlation test used to assess the association between cytokines and pain levels.

The three cohorts showed distinct inflammatory profiles. Specifically, EGF, FGF-2, MCP-3, MIP-1a, IL-8 were significant different between knee and hip OA; FGF-2, GRO, IL-8, MCP-1, VEGF were significant different between hip OA and control; Eotaxin, GRO, MCP-1, MIP-1b, VEGF were significant different between knee OA and control (p-value < 0.0012). For hip OA cohorts, cytokines do not differ between K/L grade three and K/L grade four or between patients that displayed either impingement or dysplasia. Three cytokines were significant associated with pain: IL-6 (p-value = 0.045), MDC (p-value = 0.032) and IP-10 (p-value = 0.038).

We have demonstrated that differences in serum inflammatory profiles exist between hip and knee OA patients. These differences suggest that OA may include different inflammatory subtypes according to affected joints. We also identified that the cytokine IL-6, MDC and IP-10 are associated with pain level in hip OA patients. These cytokines might help explain the inconsistent of presentation of pain with radiographical severity of OA joints. Future studies are needed to validate our findings and then to understand the following questions: (1) how differently affected joints are reflected in systematic biomarkers; (2) how these cytokines are biologically involved in the OA pain pathway.

Patients undergoing Joint Arthroplasty received a significant proportion of blood transfusions. In this study, we compared the risk of Deep Infection, and Superficial Infection post operation following Primary Total Hip or Knee replacement in blood-transfused and non-blood-transfused patients.

Cohort of patients who underwent primary total Hip or Knee Arthroplasty from April 2012 to March 2015 in Alberta. Patient characteristics, comorbidity, received blood transfusion were collected from electronic medical records, operating room information systems, discharge abstract database, provincial clinical risk grouper data. Deep Infection and Superficial Infection were captured from Provincial Surgical Site Infection Surveillance data. Deep Infection include deep incisional and organ/space infections. Logistic regression analysis were used to compare Deep Infection and Superficial Infection in blood-transfused and non-blood-transfused cohorts, and risk-adjusted for age, gender, procedure type, and co-morbidities.

Our study cohort contains 27891 patients, with mean of age at admission was 66.3±10.4, 57.5% female, 49.3% had 1 or more comorbidities. 58.8% underwent Knee Replacement. 11.1% received blood transfusion during hospital stay (Total Hip Replacement (THR) =13.1% and Total Knee Replacement (TKR) =9.7%,). 1.1% had Deep Infection (THR=1.4% and TKR=0.9%) and 0.5% had Superficial Infection (THR=0.5% and TKR=0.5%). Blood-transfused patients got 1.7% Deep Infection and 1.0% Superficial infection. Non-blood-transfused patients got 1.0% Deep Infection and 0.5% Superficial infection. Controlling for age, gender, procedure type, and co-morbidities, the odds of Deep Infection were 1.6 times higher for blood-transfused patients than for non-blood-transfused patients (adjusted odds ratio [OR]=1.6, 95% confidence interval [CI] [1.2–2.2], p=0.004). The odds of Superficial Infection were 2.0 times higher for transfused patients (adjusted OR=2.0, 95% CI [1.3–3.0], p=0.002).

Blood transfusion increases Deep Infection and Superficial Infection post-surgery following Primary Total Knee or Hip Replacement. This finding suggests to reduce the unnecessary blood transfusion for patients considering Joint Arthroplasty. Reducing the blood transfusion will save the inpatient cost and decrease the infective complications post-surgery in Hip or Knee Arthroplasty patients.

Aims

We aimed to assess the comparability of data in joint replacement registries and identify ways of improving the comparisons between registries and the overall monitoring of joint replacement surgery.

In a cross sectional cohort study three different metal on metal total hip systems were assessed. Two monoblock acetabular designs; the Durom socket (Zimmer, Warsaw, In) and the Birmingham socket (Smith and Nephew, Memphis, TN), and one modular metal on metal total hip system (Pinnacle, Depuy Orthopaedics, Warsaw, In) in patients who have received these implants in the our region. 56 patients were recruited in total. All patients were assessed clinically, radiologically and biochemically. Whole blood Cobalt, Chromium and titanium levels were tested.

The median head size used in the Birmingham group was 52mm (Range 44mm to 56mm), and in the Durom group, 48mm (Range 42 to 54mm). The median head size used in the modular Pinnacle group was 40mm (Range 36–44mm).

The blood metal ions levels in the larger non modular acetabular sockets were significantly raised compared to the Pinnacle group. For Co 1.95 µg/l and 2.70 µg/l in the Durom and Birmingham groups respectively compared to only 0.52 µg/l in the Pinnacle group (P< 0.001). Mean Cr levels were the same for the two monoblock systems, 1.9 µg/l compared to the Pinnacle sockets 1.2 µg/l (P< 0.001).

Our study clearly demonstrates that there is a significant difference in metal ion levels in patients following a monobloc large head arthroplasty system compared to a smaller modular metal on metal hip arthroplasty. The smaller head size appears to produce less metal ions whilst at the same time a 36mm–44mm head size is large enough to increase hip stability and range of movement as well as decreasing the risk of impingement. In our practice we are no longer using this design and the safest strategy, when considering metal on metal bearings, is to use a modular, smaller head system such as the Pinnacle.

Purpose

To determine whether there is a difference in the metal ion levels among three different metal-on-metal total hip systems: two monoblock large heads and one modular metal-on-metal total hip replacement system in patients who received these implants in our region.

Purpose

Elevated blood metal ions are associated with the early failure of the Hip Resurfacing Arthroplasty. The aim of this study was to analyse our prospective database of Hip Resurfacing Arthroplasty patients, to independently review the outliers with elevated blood metal ions and to determine whether a screening program would be of value at our institution.

Purpose

There are concerns with regard to the physiological effects of reamed intramedullary femoral fracture stabilisation in patients who have received a pulmonary injury. This large animal study used invasive monitoring techniques to obtain sensitive cardiopulmonary measurements and compared the responses to Early Total Care (reamed intramedullary femoral fracture fixation) to Damage Control Orthopaedics (external fixation), after the induction of acute lung injury. We hypothesised a greater cardiopulmonary response to intramedullary fracture fixation.

Summary

We report the first use of synchrotron xray spectroscopy to characterize and compare the chemical form and distribution of metals found in tissues surrounding patients with metal-on-metal hip replacements that failed with (Ultima hips) or without (current generation, large diameter hips) corrosion.

Purpose of the study

To take a snapshot opinion of General Practitioner understanding of the prevalence, diagnosis and management of coccydynia.

To assess the effectiveness of dynamic stabilisation as a treatment for discogenic pain compared to standard treatment of interbody fusion.

All patients were referred for a 2 year back-pain management programme. Patients with continued pain following conservative treatment underwent discography & MRI. Patients with painful degenerate discs on the above investigations were selected.

Patients underwent interbody fusion (PLIF/TLIF) or dynamic stabilisation.

Mean follow-up was 24 months with a minimum follow-up of 12 months.

All patients had pre-operative ODI and VAS scores. Patients were then sent further questionnaires at 6 month intervals.

The mean improvement in ODI following dynamic stabilisation was 20% (-20% → 56%), the mean improvement in the pain score was 2.4 (0→8).

The mean improvement in ODI following interbody fusion was 11% (-14%→48%), the mean improvement in the pain score was 2.6 (-4→9).

10 patients in the dynamic stabilisation group had a greater than 20% improvement in ODI, 7 patients in the interbody fusion group had similar results.

The above results demonstrate that dynamic stabilisation is at least as effective at treating discogenic pain as interbody fusion. The results however do question the validity of either interbody fusion (PLIF/TLIF) or dynamic stabilisation in the management of discogenic pain.

Previous studies have shown improved outcome following surgery for spinal cord compression due to metastatic disease. Further papers have shown that many patients with metastatic disease are not referred for orthopaedic opinion. The aims of this paper are to study the survival and morbidity of patients with spinal metastatic disease who receive radiotherapy. Do patients develop instability and progressive neurological compromise? Can we predict which patients will benefit from surgery?

Retrospective review of patients receiving radiotherapy for pain relief or cord compression as a result of metastatic disease. Patients were scored with regards to Tomita and Tokuhashi, survival and for deterioration in neurology or spinal instability.

94 patients reviewed. All patients were followed up for a minimum of 1 year or until deceased. Majority of patients had a primary diagnosis of lung, prostate or breast carcinoma.

Mean Tomita score of 6, Tokuhashi score 7, and mean survival following radiotherapy of 8 months. 11:94 patients referred for surgical opinion. Poor correlation with Tomita scores (-0.25) & Tokuhashi scores (0.24) to predict survival. Four patients developed progressive neurology on follow-up. One patient developed spinal instability. The remainder of the patients did not deteriorate in neurology and did not develop spinal instability. All patients with normal neurology at time of radiotherapy did not develop spinal cord compression or cauda equina at a later date.

This study suggests that the vast majority of patients with spinal metastatic disease do not progress to spinal instability or cord compression, and that prophylactic surgery would not be of benefit. The predictive scoring systems remain unreliable making it difficult to select those patients who would benefit. The referral rate to spinal surgeons remains low as few patients under the care of the oncologists develop spinal complications.

Introduction

Following the publication of our original survey in 2000 (Eur. Sp. J. 11(6):515-8 2002) we have sought to re-evaluate the perceptions and attitudes towards spinal surgery of the current UK orthopaedic Specialist Registrars (SpRs), and to identify factors influencing an interest in spinal surgery. At that time 175 orthopaedic spinal surgeons in the UK needed to increase by 25% to satisfy parity with other European countries.

Introduction

This study investigates the effect of somatisation on results of lumbar surgery.

It is thought that metal ions from metal on metal bearing hip replacements cause DNA damage and immune dysfunction in the form of T cell mediated hypersensitivity. To explore the hypothesis that there is a relationship between metal ion levels and DNA damage and immune dysfunction in matched patient groups of hip resurfacings and standard hip replacements reflected in the levels of lymphocyte subtypes (CD3+ T cells, CD4+ T helper cells, CD8 +T cytotoxic/suppressor cells, CD16 +Natural Killer and CD19+ B cells) in peripheral blood samples, we analysed peripheral blood samples from 68 patients: 34 in the hip resurfacing group and 34 in the standard hip arthroplasty group. Samples were analysed for counts of each sub-group of lymphocyte and cytokine production. Whole blood cobalt and chromium ion levels were measured using inductively-coupled mass spectrometry. All hip components were well fixed.

Cobalt and chromium levels were significantly elevated in the resurfacing group compared to the hybrid group (p<0.001). There was a statistically significant decrease in the resurfacing group's level of CD8+ cells (T cytotoxic/suppressor) (p=0.010). No other subgroup of lymphocytes was significantly affected. Gamma interferon levels post antigen challenge were severely depressed in the hip resurfacing group.

A threshold level of blood cobalt and chromium ions for depression of CD8+ T cells was observed. Hip resurfacing patients have levels above this threshold whilst standard hip replacements fall below it. The patients all had normal levels of CD16 +Natural Killer and CD19+ B cells suggesting that this is not a bone marrow toxic effect. Cytokine analysis confirmed that some aspects of T cell function in hip resurfacing patients are severely depressed.

Objective

To assess the effectiveness of dynamic stabilisation as a treatment for discogenic pain compared to standard treatment of interbody fusion.

Study Design & Subjects

All patients were referred for a 2 year back-pain management programme. Patients with continued pain following conservative treatment underwent discography & MRI. Patients with painful degenerate discs on the above investigations were selected.

Patients underwent interbody fusion (PLIF/TLIF) or dynamic stabilisation.

Mean follow-up was 24 months with a minimum follow-up of 12 months.

Introduction: Surgical fixation of intra-articular distal femoral fractures has been associated with nonunion & varus collapse. The soft tissuestripping associated with this fracture andthe surgical exposure have been factors associated with delayed union & infection. The limited soft tissue exposure has been lauded the as a solution to this fracture. However, it has occurred with the new fixation as well.(Locked Plate)

Aims: This study is an attempt to look at the fixation. Does the LISS system improve the results of this difficult fracture? Is there truly a difference in the outcome of this fracture utilizing the Locked plate system or is the percieved difference due to the surgical mini invasive approach.

Patients & Methods: One hunderd & forty patients were screened, only 53 were randomized and fixed in six academic centers over 5 years. All C3 fractures were excluded as they were felt not to be treatable by the DCS device, but they were treated appropiately. 35 females and 18 males were included in the study and randomized appropiatley.

Results: Fifty-three patients were randomized, 28 had the LISS implant and 25 had the DCS utilized. There were 3 nonunions in the LISS group plus two patients with early loss of reduction that required reoperation in the early post operative period. One patient developed arthrofibrosis requiring arthroscopic release and subsequently the implant failed necessitating refixation. In the DCS group, only one nonunion reported & required second surgery. This translated to a reoperation rate of 21% in the LISS group compared to 4% with DCS.

Conclusion: This prospective randomized multicentre trial showed a difference when comparing the LISS to the DCS in the supracondylar distal femur fractures.

The recent NICE guidelines on management of osteoarthritis outline weight loss as first line treatment in degenerative joint disease in the obese. There is little data surrounding the effects of obesity on the outcomes in spinal surgical interventions. Intervertebral discectomy is one treatment for prolapse of a lumbar vertebral disc. We aim to investigate the effect of obesity on outcomes for discectomy.

Demographic details including age, sex, weight and BMI were recording with a pre-operative Oswestry Disability Index (ODI). The fat thickness was measured at L5/S1 using calibrated MRI scans. Outcome measures included complications, length of surgery and change in ODI at 1 year following surgery. Obesity was defined as a body mass index of over 30. The units Serial patients undergoing discectomy were recruited into the study. Patients with bony decompression, instrumentation, revision surgery or multilevel disease were excluded.

Fifty patients with a single level uncomplicated disc prolapse were entered into the study. Sixteen patients had a BMI over 30 and so were obese, whilst 34 had a BMI of less than 30. The mean pre-operative ODI was 46.5 in the obese group and 52 in the normal group this difference was not significant (p> 0.05). The mean post operative ODI was statistically improved in the high BMI group at 28 (18.5 point improvement) and 25.2 (29.1 point improvement) in the normal group. The ODI improvement was significantly better in the low BMI group (p=0.036). There was no significant difference in operative time (p=0.24). Only a single patient had a complication (dural leak), so no valid comparison could be made.

The outcomes of spinal surgery in the obese are mixed.

We found no increase in the complication rate or intra-operative time associated with an increased BMI. However, the improvement in ODI was significantly better in the normal BMI group.

Aims: There are concerns over the physiological effects of intramedullary femoral fracture stabilisation in patients with pulmonary injury. This large animal study used invasive monitoring to obtain sensitive cardiopulmonary measurements and compared the responses of ‘Early Total Care’ (intramedullary fracture fixation) and ‘Damage Control’ (external fixation), after the induction of lung injury.

Methods: Acute lung injury (PaO2/FiO2 < 200 mmHg) was induced in 12 invasively monitored and terminally anaesthetised sheep via oleic acid infusion into the right atrium. Each animal underwent surgical femoral osteotomy and fixation with either reamed intramedullary (n=6) or external fixation (n=6). Haemodynamic and arterial blood-gas measurements were recorded at baseline, 5, 30 and 60 minutes after fracture stabilisation.

Results: The mean (+/− S.E.) PaO2/FiO2 fell significantly (p< 0.05) from 401 (+/− 39) to 103 (+/− 35) and 425 (+/− 27) to 122 (+/− 21) in the externally fixated and intramedullary nailed groups respectively after acute lung injury. The further combined effect of surgical osteotomy and fracture fixation produced a mean (+/− S.E.) PaO2/FiO2 of 98 (+/− 21) and 114 (+/− 18), in the externally fixated and intramedullary nailed groups immediately after surgery. This was not significantly different within or between groups. Similarly the pulmonary vascular resistance (PVR) measured at 5.8 (+/− 0.8) and 4.8 (+/− 0.7) after lung injury in the externally fixated and intramedullary nailed groups changed to 5.7 (+/− 0.5) and 4.0 (+/− 0.7) after surgical osteotomy and fracture fixation (no significant difference within or between groups). The PaO2/FiO2 or PVR was not significantly different at the monitored 5, 30 and 60 minute intervals after fracture stabilisation.

Conclusion: Against a background of standardised acute lung injury, there was no further deterioration produced by the method of isolated femoral fracture fixation in sensitive physiological parameters commonly used during intensive care monitoring.

Introduction: There is little evidence for the long term efficacy of selective nerve root injections (SNRI) in the control of lumbar radiculopathy. We report the 5 year results of a prospective study of SNRI in the lumbar spine.

Methods: All patients considered to be operative candidates by two treating surgeons (JMP and DJS) with unilateral/bilateral radicular leg pain were included. Patients had a mean history of radicular symptoms of 12.8 months (4 months–3 years). All had an SNRI under image intensifier control with local anaesthetic and steroid. Each patient was evaluated pre-operatively, 2 months, 6 months, 1 year, 2 year and 5 years with VAS and ODI scores.

Results: Sixty-two consecutive patients were reviewed. The mean age of patients was 54.5 years (36–80 years). 92 injections were performed. Symptoms were caused by degenerative disease (n=32), disc herniation (n=25), and previous surgery (n=3).

The ‘disc’ group was significantly younger than ‘degenerative’ group (49.4 yrs vs. 58.4 yrs; p=0.004). There were significant improvements in low back pain (LBP), leg pain (LP), and ODI at 2 months in all patients. At 5 years the disc group did better with both leg and back pain; whilst there was only a significant reduction in leg pain in the degenerative group. Over 90% (n=56) of patients had no operative intervention; a subgroup of 8 had further injections. Within the degenerative group, ODI and VAS deteriorate early on indicating that a second injection option in this group may be worthwhile.

Conclusion: At five-years, most patients avoid operative treatment because of improved symptom control with SNRI. Regression analysis showed “duration of symptoms” and “age” is predictive of good outcome at one year post SNRI, but gender and, diagnosis are not.

Previous studies have shown improved outcome following surgery for spinal cord compression due to metastatic disease. Further papers have shown that many patients with metastatic disease are not referred for orthopaedic opinion. The aims of this paper are to study the survival and morbidity of patients with spinal metastatic disease who receive radiotherapy.

Do patients develop instability and progressive neurological compromise?

Do patients require surgery or are the majority adequately treated by oncologists?

Review of patients receiving radiotherapy for pain relief or cord compression as a result of metastatic disease. Patients were scored with regards to Tomita and Tokuhashi, survival and for deterioration in neurology or spinal instability.

94 patients reviewed. All patients were followed up for a minimum of 1 year or until deceased.

Majority of patients had a primary diagnosis of lung, prostate or breast carcinoma.

Mean Tomita score of 6, Tokuhashi score 7, and mean survival following radiotherapy of 8 months.

11:94 patients referred for surgical opinion.

Four patients developed progressive neurology on follow-up.

One patient developed spinal instability. The remainder of the patients did not deteriorate in neurology and did not develop spinal instability.

All patients with normal neurology at time of radiotherapy did not develop spinal cord compression or cauda equina at a later date.

This study suggests that the vast majority of patients with spinal metastatic disease do not progress to spinal instability or cord compression, and that prophylactic surgery would not be of benefit.

The referral rate to spinal surgeons remains low as few patients under the care of the oncologists develop spinal complications.

Introduction and aim: We have previously shown an association between whole blood metal ions and reduced CD8+ T cells in patients with unilateral metal on metal (MOM) hip resurfacings. Our aim was to substantiate this controversial finding with a follow up cohort of larger numbers of patients before further immunological investigation.

Method: We measured lymphocyte subset counts and whole blood Cobalt and Chromium in 2 groups of patients: a Birmingham hip resurfacing group (n=100); and a metal on polyethylene MOP hip arthroplasty group (n=34). Metal ions were measured using inductively-coupled mass spectrometry (ICP-MS) with a Dynamic Reaction Cell (DRC). The detection limit was 10 parts per trillion. All hip components were well fixed, clinically and radiologically.

Results: Cobalt and chromium levels were significantly elevated in the MOM resurfacing group compared to the MOP group (p< 0.0001). There was a statistically significant decrease in the MOM resurfacing groups’ level of CD8+cells (T cytotoxic) (p=0.005) when analysed by a Mann-Whitney U test. There was no significant difference between levels of CD4+ (T helper cells), CD19+ (B cells) and CD16/56+ (Natural Killer cells). A threshold level of blood cobalt and chromium ions for depression of total numbers CD8+ T cells was observed.

Conclusions: This follow up cohort of 100 MOM hip resurfacing patients has replicated the association of reduced CD8+ T cells and raised metal ion levels observed in our founder cohort. This was specific to CD8+ T cells. We are now more certain that this association needs further detailed immunological investigation.

Introduction and aim: We have previously shown suppressed levels of CD8+ T lymphocytes in patients with metal-on-metal (MOM) hip resurfacing compared to patients with metal on polyethylene hip replacements. Functional assessment of T lymphocytes may help to determine the importance of this CD8+ reduction following hip resurfacing.

Method: We isolated peripheral blood mononuclear cells (PBMC) from patients with unilateral MOM hip resurfacing (n=7) and healthy controls without hip replacement (n=8). Patients with hip resurfacing had excellent Harris Hip scores (mean 90) and well fixed components on radiographs. Whole blood and serum levels of Cobalt (Co) and Chromium (Cr) ions were measured with Inductively-Coupled Mass Spectrometry. T cell function was assessed by

cell proliferation assays (3H-thymidine incorporation) and

Results: Co and Cr ion levels were significantly elevated in the MOM hip resurfacing group compared to the control group (p< 0.001). Proliferation rates of T cells were comparable between the two groups over one week, but interferon-gamma (IFN-γ) production in the MOM hip resurfacing group was significantly decreased (p < 0.05), when compared to the control group.

Conclusion: IFN-γ is normally produced by CD8+ (T cytotoxic cells) and CD4+ (T helper 1 cells) in response to viral infection and high levels of IFN-γ is associated with autoimmune disease. Raised levels of metal ions from hip resurfacing reduces the production of IFN-γ following stimulation with PHA. This finding has been patented for potential therapeutic use through MRC technology.

Introduction: This study investigates the effect of somatisation on results of lumbar surgery.

Methods: Pre- and postoperative data of all primary discectomies and posterior lumbar decompressions was prospectively collected. Pain using the Visual Analogue Score (VAS) and disability using the Oswestry Disability Index (ODI) were measured. Psychological assessment used the Distress Risk Assessment Method (DRAM). Follow-up was at 1 year.

Results: There were a total of 320 patients (average age 49.7 years). Preoperatively there were 61 Somatising and 75 psychologically Normal patients. 47 of the pre-operative Somatisers were available for follow-up.

All pre-operative parameters were significantly higher compared with the Normal group (back pain VAS 6.3 and 3.8; leg pain VAS 7 and 4.7; ODI 61 and 34.4 respectively).

At 1 year follow-up, 23% of the somatising patients became psychologically Normal; 36% became At Risk; 11% became Distressed Depressed; and 30% remained Distressed Somatisers.

The postoperative VAS for back and leg pain of the 11 patients who had become psychologically Normal was 3.4 (pre-op 6.8) and 3.2 (pre-op 6.6) respectively. In the 14 patients who remained Distressed Somatisers the corresponding figures were 5.6 (pre-op 7.8) and 6.7 (pre-op 7.0).

The postoperative ODI of the 11 patients who had become psychologically Normal was 26.4 (pre-op 55.5). In the 14 patients who remained Distressed Somatisers the corresponding figures were 56.7 (pre-op 61.7).

These differences are statistically significant.

Discussion: Patients with features of somatisation are severely functionally impaired preoperatively. One year following lumbar spine surgery, 60%(28) had improved psychologically, 23%(11) were defined as psychologically normal. This was associated with a significant improvement in function and back and leg pain. The 14(30%) patients who did not improve psychologically and remained somatisers had a poor functional outcome. Our results demonstrate that psychological distress is not an absolute contraindication to lumbar spinal decompressive surgery.

Introduction: This study investigates the effect of soma-tisation on results of lumbar surgery.

Methods: Pre- and postoperative data of all primary discectomies and posterior lumbar decompressions was prospectively collected. Pain using the Visual Analogue Score (VAS) and disability using the Oswestry Disability Index (ODI) were measured. Psychological assessment used the Distress Risk Assessment Method (DRAM). Follow-up was at 1 year.

Results: There were a total of 320 patients (average age 49.7 years). Preoperatively there were 61 Somatising and 75 psychologically Normal patients. 47 of the pre-operative Somatisers were available for follow-up.

All pre-operative parameters were significantly higher compared with the Normal group (back pain VAS 6.3 and 3.8; leg pain VAS 7 and 4.7; ODI 61 and 34.4 respectively).

At 1 year follow-up, 23% of the somatising patients became psychologically Normal; 36% became At Risk; 11% became Distressed Depressed; and 30% remained Distressed Somatisers.

The postoperative VAS for back and leg pain of the 11 patients who had become psychologically Normal was 3.4 (pre-op 6.8) and 3.2 (pre-op 6.6) respectively. In the 14 patients who remained Distressed Somatisers the corresponding figures were 5.6 (pre-op 7.8) and 6.7 (pre-op 7.0).

The postoperative ODI of the 11 patients who had become psychologically Normal was 26.4 (pre-op 55.5).

In the 14 patients who remained Distressed Somatisers the corresponding figures were 56.7 (pre-op 61.7).

These differences are statistically significant.

Discussion: Patients with features of somatisation are severely functionally impaired preoperatively. One year following lumbar spine surgery, 60%(28) had improved psychologically, 23%(11) were defined as psychologically normal. This was associated with a significant improvement in function and back and leg pain. The 14(30%) patients who did not improve psychologically and remained somatisers had a poor functional outcome. Our results demonstrate that psychological distress is not an absolute contraindication to lumbar spinal decompressive surgery.

Introduction: Following the publication of our original survey in 2000 (Eur. Sp. J.11(6):515–8 2002) we have sought to re-evaluate the perceptions and attitudes towards spinal surgery of the current UK orthopaedic Specialist Registrars (SpR’s), and to identify factors influencing an interest in spinal surgery. At that time 175 orthopaedic spinal surgeons in the UK needed to increase by 25% to satisfy parity with other European countries.

Methods: A postal questionnaire was sent to all 950 SpR’s. The questionnaire sought to identify perceptions in spinal surgery, levels of current training and practice, and intentions to pursue a career in spinal surgery.

Results: As before, a 70% response rate has confirmed that 74% of trainees intend to avoid spinal surgery (69% in 2000). However 10% are committed to become a Specialist Spinal Surgeon (9% in 2000). Their perceptions were wide ranging but most concluded that the intellectual challenge and opportunities for research are widely recognised. However enthusiasm is dampened by poor perceptions of outcomes from surgery, negative somatization and depression associations, complications and the fear of litigation. In some areas there is inadequate exposure to spinal surgery during the first 4 years of training.

Conclusions: Spinal surgery remains a career choice for 10% of surgical trainees (up 1% since 2000). With a large SpR expansion (578 to 950 SpRs in the last 5 years) an average of 16 new spinal surgeons annually will be produced over the next six years. This has improved on the figure of 8.6 per year from 2000 and represents a 200% increase in numbers per year. These figures suggest that by 2011 and allowing for retirement, there should be enough spinal surgeons to meet the desired UK/Europe ratio.

Introduction: There have been 70,000 hip resurfacings implanted, predictions are for it to become 12% of the US hip replacement market by 2010 (Goldmann Sachs report Oct 2005). There is concern that the cobalt and chromium ions released from metal on polyethylene hip replacements cause immune dysfunction in the form of T cell mediated hypersensitivity (indicated by increased numbers and stimulation of T cells). If metal ions cause significant effects on white blood cells we might reasonably expect to detect this by simply measuring numbers of white blood cells.

Aim : To examine the possibility that raised metal ions may cause an abnormal number of white blood cells, termed a blood dyscrasia.

Method : Peripheral blood samples were analysed from 68 patients: 34 in the hip resurfacing group and 34 in the standard hip arthroplasty group. Samples were analysed for counts of each sub-group of lymphocyte. Functional assessment was also performed using a activation panel of white cell CD markers. Whole blood cobalt and chromium ion levels were measured using inductively-coupled mass spectrometry. All hip components were well fixed.

Results : Cobalt and chromium levels were significantly elevated in the resurfacing group compared to the hybrid group (p< 0.001). There was a statistically significant decrease in the resurfacing groups’ level of CD8⁺ cells (T cytotoxic/suppressor) (p=0.010). There was a characteristic pattern of immune modulation seen on the activation panel.

Conclusions : We found an immune modulation in patients with metal on metal hip resurfacing. This was not a hypersensitivity reaction. This change in T cell function may be detrimental or beneficial to patients.

The British Orthopaedic Association has endorsed a website, www.orthoconsent.com, allowing surgeons free access to a bank of pre-written consent forms. These are designed to improve the level of information received by the patient and lessen the risk of successful litigation against surgeons and Health Trusts.

Purpose: The purpose of this study is to evaluate the hemodynamic and pulmonary effects of intramedullary nailing with a removable filter placed into the common iliac vein.

Methods: Under general anaesthesia, a collapsible filter was inserted into the left common iliac vein in eight dogs and compared to a control group from a previous study. The left femora and tibiae were then pressurized by injection of bone cement and the insertion of intramedullary rods. Echocardiographic images and hemodynamic measurements including arterial blood gas, cardiac output, left atrial, right atrial, pulmonary arterial, and aortic pressure were recorded as baseline measurements and at 1, 5 and 15 minutes after medullary-canal pressurization. After fifteen minutes of pressurization the filter debris was evacuated, the samples sent for analysis and the filter was collapsed and removed. The dog’s hemodynamics were then monitored for a further fifteen minutes. The animals were killed and the lungs were harvested for histomorphometric analysis.

Results: Full hemodynamic and histomorphometric results of the lung tissue and debris collected from the evacuated filters are still pending at the time of this submission however initial findings indicate that the filter prevented an immediate increase in mean pulmonary artery pressure after canal pressurization. No large embolic event was visualized in any of the filtered dogs. In contrast, all animals in the control group demonstrated moderate-to-severe echogenic response with intense showering of echogenic material, including large embolic masses. Removal of the filter was safe and repeatable.

Conclusions: This experiment has shown that proximal venous blockade by means of a removable filter was able to reduce the size and the quantity of the embolic load on the lungs and the filter could be safely collapsed and removed after suctioning of the debris. High rates of embolization causing increased morbidity and mortality after intramedullary stabilization of pathological fractures and of traumatic fractures with concomitant lung injury have been reported. Prophylactic insertion of a removable temporary filter in this high-risk group prior to reamed intramedullary nailing may be beneficial.

Funding : Other Education Grant

Funding Parties : Synthes Canada

Using an established canine model of fat embolization, the effect of temporary mechanical blockade of embolic load during medullary canal pressurization was studied. Haemodynamic measurements, echocardiography and postmortem histomorphometry were used as outcome measures. There was statistically significant difference between the filter and the control groups, when the pulmonary vascular resistance, the percentage area of lungs occupied by fat and the percentage of pulmonary vasculature occupied by fat were compared. We have shown that mechanical blockade by a filter does stop the adverse effect on the lungs during canal pressurization.

Acute intramedullary stabilization of femoral fractures in multiply injured patients still remains controversial. Intravasation of medullary fat has been suspected to trigger ARDS. This study investigates the effect of a filter placed into the ipsilateral common iliac vein during medullary canal pressurization.

Using an established canine model, twelve mongrel dogs were randomized into two groups. A special filter was inserted percutaneously into the left common iliac vein in half the dogs where as the other half served as controls. In all dogs, the left femora and tibiae were pressurized by injection of bone cement and insertion of intramedullary rods. Hemodynamic measurements and echocardiography images were recorded continuously. After sacrifice, the lungs were harvested for analysis.

The mean pulmonary artery pressure at three minutes of pressurization was 12 mm of Hg in the filter group and 28mm of Hg in the control group. The pulmonary vascular resistance in the control group was increased from the 3^rd minute of pressurization throughout the experiment. This was statistically significant when compared with the baseline. There was no such change seen in the filter group. Transesophageal echocardiography showed less embolic shower in the filter group and histomorphometry demonstrated statistically signifant difference, when the percentage area of lungs and the percentage of pulmonary vasculature occupied by fat in the filter group as compared to the control group.

This canine study has demonstrated that mechanical blockade by a venous filters can significantly reduce the embolic load on the lungs during canal pressurization.

Introduction: Early stabilization of the skeleton in multiply injured patients has shown to reduce mortality and chest morbidity. Reamed intramedullary nailing is the current method of choice for stablizing femoral and tibial shaft fracture. However several investigators have highlighted the adverse effect of early reamed nailing in polytrauma patients. Intravasation of medullary fat during canal pressurizaton has been suspected to produce a ‘second hit’ and trigger pneumonia and ARDS. The objective of this study is to investigate the effect of a filter placed into the ipsilateral common iliac vein during medullary canal pressurization.

Methods: Using an established model of fat embolization, twelve mongrel dogs were randomized into two groups. Under general anaesthesia, cannulations of carotids and jugular veins and transesophageal echo-cardiography were performed in all animals. Under fluoroscopy control, a special filter was inserted percutaneously into the left common iliac vein in half the animals, where as the other half served as controls. In all dogs, the left knee was exposed; the femor and tiiba were sequentially reamed and then pressurized by injection of bone cement and insertion of intramedullary rods. Hemodynamic measurements and trans-esophageal echocardiography images were recorded continuously during the surgical procedure. After 45 minutes from pressurization, the dogs were sacrificed and the lungs and kidneys were harvested and fixed for histological analysis.

Results: There was significant difference noticed in the right-sided pressures and oxygen tension between the filter and the control groups. The mean pulmonary artery pressure at 3 minutes of pressurization was 12mm of Hg in the filter group and 28mm of Hg in the control group. Transesophageal echocardiography showed less embolic shower in the filter group and also lesser dilatation of right ventricles. Histomorphometry with special staining demonstrated much less proportion of lungs to be occupied by fat in the filter group as compared to the control group.

Discussion and Conclusion: This canine study has demonstrated that mechanical blockade by a venous filter can significantly reduce the emobilic load on the lungs in an established model of fat embolization. A suitable filter with suction system is being designed for possible use in high-risk patients.

Introduction: With the rising popularity of biological fixation, “Less invasive skeletal stabilisation system” (L.I.S.S.) has emerged as a valid option to treat complex fractures around the knee. Published reports have shown good results with shorter healing time and lesser re-operation rates. However as with any close procedure, restoring correct alignment of the limb could be difficult with this system and has not been reported previously. We report the results of CT alignment study in 20 cases of LISS fixation.

Methods: In a combined retrospective-prospective study, 20 patients, who were treated with LISS system for stabilizing either femoral or tibial fractures were enrolled. Patents with only unilateral fractures with a normal contra-lateral lower limb were included. All patients had CT scannograms and limited axial CT cuts of both lower limbs. Axial and rotational alignments were measured and assessed by one consultant radiologist.

Result: There were 9 cases of femoral and 11 cases of tibial LISS . The mean total malrotation was found to be 11.97 degrees (2.0–34.5). All femora were found to be malrotated externally with a mean of 11.71 degrees where as for the tibiae the mean internal and external malrotaions were found to be12.53 and 11.74 respectively. Mean coronal malalignment was found to be 3.76 degrees. If acceptable alignment was taken as 5 degrees in any plane, then the degree of malrotation in our study was found to be statistically significant.

Discussion and conclusion: Malalignment, mainly in the rotational plane has been reported in other closed techniques such as femoral and tibial nailing. As LISS is also minimally invasive and done through indirect reduction techniques, restoration of correct alignment could be difficult to achieve. This study is reassuring as we have found that generally, alignment of limb in our study was satisfactory and no corrective surgery was needed.

Introduction and Aims: Acute intramedullary stabilisation of femoral shaft fractures in multiply injured patients remains controversial. Intravasation of medullary fat during nailing has been suspected to trigger ARDS. This study investigates the effect of a filter placed into the ipsilateral common iliac vein during medullary canal pressurisation in a canine experiment.

Method: Using an established model, 12 mongrel dogs were randomised into two groups. Under general anesthesia, cannulations were performed to measure left and right-sided pressures. Transoesophageal echocardiography was performed in all dogs. A special ‘TRAP ‘filter was inserted percutaneously into the left common iliac vein in six dogs, whereas the other six served as controls. In all dogs, the left femora and tibiae were then pressurised by injection of bone cement and insertion of intramedullary rods. Hemodynamic measurements and echocardiography images were recorded continuously. After one hour, the animals were sacrificed and the lungs were harvested for histomorphommetric analysis.

Results: The mean pulmonary artery pressure at three minutes of pressurisation was 12mm of Hg in the filter group and 28mm of Hg in the control group. There was increase in the peak systolic pulmonary artery pressure and the right ventricular pressure after canal pressurisation in the control group, whereas no such changes were observed in the filter groups. The pulmonary vascular resistance as denoted by the difference between the mean pulmonary artery pressure and the end diastolic left ventricular pressure increased significantly (p< 0.05) at three, five, 10,15 and 30 minutes after pressurisation in the control group when compared to the baseline value. In the filter group, the pulmonary vascular resistance increased only slightly after pressurisation. Transesophageal echocardiography images were analysed by a blinded echocardiologist. There was evidence of moderate to severe embolisation in the control group with detection of large echogenic particles. In comparison, there was mild grade of embolisation in the filter group. Histological analysis showed statistically significant difference between the two groups, when comparison of the percentage of area of lung tissue occupied by fat, the percentage of pulmonary vasculature occupied by fat and the maximum size of the embolus were made (p< 0.05).

Conclusion: This study has conclusively demonstrated that mechanical blockade by venous filters prior to medullary canal pressurisation, significantly reduces the embolic load and its effect on the lungs. A retrievable filter with a system to remove the accumulated marrow content is being developed for use in high-risk patients.

Study Design: Prospective cohort study.

Objectives: To evaluate outcomes for back pain following primary single level spinal decompression for nerve root pain.

Subjects: All patients were managed in a single spinal unit with two spinal surgeons following the same management protocol. Any patient undergoing spinal fusion was excluded. Over a five-year period there were 217 patients, with a mean age of 39 years (15 to 78 years). The male to female ratio was 1:1. All had specific single level nerve root pain and definite nerve root compromise confirmed on MRI.

Outcome Measures: All patients were assessed preoperatively and followed at 3, 6, 12 and 24 months using a standard back pain questionnaire including visual analogue scores for leg and back pain, a pain diagram, Oswestry disability index (ODI), Zung depression index and somatisation scores.

Results: We report a statistically significant improvement in back pain post-operatively with 68.6% of patients improving their score (p < 0.001 sign test) with 19.5% reporting complete relief. This improvement was sustained over the follow-up period. Post-operative improvements in back pain correlated well with post surgical reduction in leg pain score, and ODI. Patients with increased back pain scores (> 5) at presentation, were more likely to report an improvement. In this group 80.5% reported a significant reduction in their back pain following surgery. No correlation could be identified between back pain scores and somatisation and Zung depression indices, age, gender or employment status.

Conclusions: These results are contrary to other reported series and suggest the prognosis for back pain following primary single level spinal decompression may be better than anticipated.

Study Design: A retrospective cross sectional cohort study of degeneration of the lumbar spine, using pre- and post-discography MRI scans of 28 patients, as compared to two consecutive MRI scans of an age and sex matched control group of 32 patients.

Objective: To determine whether injection of steroid into a lumbar intervertebral disc causes degeneration, as assessed by magnetic resonance imaging (MRI).

Methods: Twenty-eight patients with chronic discogenic low back pain were selected. Each had been investigated with an MRI, discography (with intradiscal injection of methylprednisolone), and a post-discography MRI scan. A randomly selected control group of thirty-two age and sex matched patients, having been examined on two occasions with MRI, was established. Two interpreters blinded to the patient groups assessed the degree of lumbar disc degeneration on the MRI scans on two separate occasions, using the Pfirrmann grading system.

Results: Kappa values proved interpretation consistency as compared with the published Pfirrmann paper. Variables of age and sex in the two groups showed no true variation in whether the discs improved, stayed the same or degenerated. The difference in the proportions for those with and without the injection gave a test statistic of 11.92 (p-value=0.002), indicating a discrepancy in the degeneration between those discs with and without an injection.

Conclusion: Previous studies on intradiscal steroid injections have shown variable results. Animal studies have shown that steroid administered intradiscally causes degeneration and primary calcification in discs. Two prospective double blind clinical trials using intradiscal steroids identified no significant benefit or improvement in the clinical outcome. This study indicates that intradiscal steroid injections cause MRI visible disc degeneration. In association with the results of the clinical trials, this study questions the indications for the use of intradiscal steroids in the management of discogenic low back pain.

Study Design: A retrospective study of the clinical outcome of patients with lumbar discogenic pain with Modic changes on MRI prior to intradiscal steroid injection.

Objectives: To determine whether the clinical outcome of patients with discogenic back pain who underwent intradiscal steroid injection could be predicted from MRI Modic changes.

Methods: The pre-operative scans were studied by two senior spinal surgeons. The lumbar vertebral end-plate changes were then classified according to the method described by Modic. The intra- and inter-observer ratings were satisfactory.

Subjects: 40 patients with discogenic back pain were recruited in this study. The mean age was 43.6 years (23 to 72 years). The male to female ratio was 1 to 1.

Outcome Measures: The clinical outcomes at six months post-intradiscal steroid injection were correlated with the Modic changes. The clinical outcomes were assessed using visual analogue scores for back pain as well as Oswestry disability index (ODI). At least a 2-point improvement in visual analogue score and a 20-point improvement in ODI were required to indicate significant symptomatic relief.

Results: We found that in those patients without Modic changes there was improvement of the low back pain in 9% (1/11). In those with Modic I changes there were significant relief in 64% (9/14), moderate relief in 29% (4/14) and no relief in 7% (1/14). In those with Modic II changes there were significant relief in 27% (4/15), moderate relief in 27% (4/15) and no relief in 47% (7/15). There were no cases with Modic III changes.

Conclusions: Previous studies on intradiscal steroid injections have shown variable results. Two prospective double-blind clinical trials, using intradiscal steroids, identified no significant benefit or improvement in the clinical outcome. Our results however suggest that patients with Modic I changes on MRI are most likely to benefit from intradiscal steroid injection in the short term.

We randomised prospectively 44 patients with fractures of the shaft of the humerus to open reduction and internal fixation by either an intramedullary nail (IMN) or a dynamic compression plate (DCP). Patients were followed up for a minimum of six months. There were no significant differences in the function of the shoulder and elbow, as determined by the American Shoulder and Elbow Surgeons’ score, the visual analogue pain score, range of movement, or the time taken to return to normal activity. There was a single case of shoulder impingement in the DCP group and six in the IMN group. Of these six, five occurred after antegrade insertion of an IMN. In the DCP group three patients developed complications, compared with 13 in the IMN group. We had to perform secondary surgery on seven patients in the IMN group, but on only one in the DCP group (p = 0.016).

Our findings suggest that open reduction and internal fixation with a DCP remains the best treatment for unstable fractures of the shaft of the humerus. Fixation by IMN may be indicated for specific situations, but is technically more demanding and has a higher rate of complications.