Introduction

Iliac crest bone marrow aspirate (ICBMA) is frequently cited as the ‘gold-standard’ source of MSCs. MSCs have been shown to reside within the intramedullary (IM) cavities of long-bones [Nelea, 2005] however a comparative assessment with ICBMA has not yet been performed and the phenotype of the latter compartment MSCs remains undefined in their native environment.

Introduction/aims

Carpal tunnel decompression is common at the world's largest lamb processing plant. The purpose of this study was to establish whether lamb boning caused carpal tunnel syndrome, whether expeditious rehabilitation was possible and current New Zealand Orthopaedic practice.

Background, Context and Motivation

“Increases in reconstructive orthopaedic surgery, resulting from advances in surgical practice and the ageing population, have lead to a demand for bone graft that far exceeds supply.”…Traditional bone grafting methods have been linked with a number of negative issues including increased morbidity due to secondary operation site and action as a vector for spread of disease. (Hing 2004). A solution to these insufficiencies would be the creation of a synthetic osteoinductive bone graft material. This would vastly improve bone graft surgery success rates and expedite post-op recovery times. The aim of this study was to classify then explore the dissolution rates of three experimental hydroxyapatite/silicate apatite synthetic bonegrafts in physiological solutions, (phosphate buffered saline, (PBS) +/− serum proteins, (PBS +FCS). The overall objective being to identify whether there is an explainable significant difference in ion exchange that could be behind the osteoinductive phenomena.

Introduction

Therapeutic exploitation of MSCs in orthopaedics has been tempered by their scarcity within ‘gold-standard’ iliac crest bone marrow aspirate (ICBMA) and the resulting need to expand cells in vitro. This is time-consuming, expensive and results in cells with a reduced differentiation capacity. [Banfi 2000] The RIA is a device that provides continuous irrigation and suction during reaming of long bones. Aspirated contents pass via a filter, trapping bony-fragments, before moving into a ‘waste’ bag, from which MSCs have been previously isolated. [Porter 2009] We hypothesised that ‘waste’ RIA bag contains more MSCs than a standard aspirated volume of ICBMA (30 ml). We further hypothesised than a fatty solid phase within this ‘waste bag’ contains many MSCs trapped within the adipocyte-rich stromal network and hence requiring an enzymatic digestion for their efficient release [Jones 2006].

Background

The mechanical disadvantage and detrimental effect to articular cartilage following meniscectomy has been well documented in the literature. Meniscal repair in the avascular (white on white zone) is controversial and would be deemed inappropriate by many.

Spinal cord injury following trauma is initially dealt with by acute hospitals. The early management including stabilization is usually performed by these centres. This is followed by onward referral to one of the Regional Spinal Injury Units.

There is concern of both sides of the fence regarding mobilization following spinal cord injury. The acute hospitals want to avoid the problems of prolonged recumbency and the Regional Spinal Injury Units wish to avoid the problems of early aggressive mobilization.

Therefore, we set out to discover if there was a standard approach to mobilising these patients following surgical stabilization, because of the oversubscribed resources of the spinal injury units and the wish to start mobilizing the injured as soon as possible.

A comparative audit of the Regional Spinal Injury Units in the UK and North American Units.

Regional Spinal Injury Units in United Kingdom and North America

Clear Management Plan

Mobilisation Schedule

We had replies from all Regional Spinal Injury Units in the UK and from seven in North America.

The Regional Spinal Injury Units all had differing approaches. Only a few were able to convey a clear management plan and mobilization schedule. Whereas the North American Units provided a ‘mobilize as able’ plan in all cases.

The North American Units had a ‘mobilize as able’ policy, whereas the UK units had a mixed approach. A coherent collaboration between the spinal surgeons stabilizing these injuries and the spinal injury units providing rehabilitation would improve patient management.

To assess adverse events related to XLIF approach in lumbar degenerative disease.

Recently novel minimally disruptive spine procedure eXtreme lateral Interbody Fusion i.e XLIF has been developed. It is 90 (off the midline true lateral approach, which allows large graft placement, excellent disc height restoration and indirect decompression at the stenotic motion segment. We describe our experience in 28 patients.

Retrospective review of records of patients undergoing surgery between July 2008- Jan 2010. Presenting complaints, number of levels performed and complications (medical, approach, or implant related) were audited.

Results: 28 patients (17 female: 11 male) with median age of 47 yrs, range (38-75) formed the study group. Average stay was 4 days. All patients had MRI of lumbar spine. 2/3 rd patients had low back pain as their presenting complaint. All patients had nerve monitoring through out the procedure. There were 12 single, 15 two level and 1 three level cases (total 45 levels). 14/28 patients underwent plating at the same time. EBL was 100ml. There were 11/45 adverse events (24.4%). 6 events were approach, 4 were implant bone interface and 1 medical related. Major complication occurred in 1 patient (3.6%).

2/3 rd of patients, were better after the surgery. Almost negligible blood loss, low infection rate and short average stay seemed to work in favour of this approach. Complications are there as (with any new procedure) our results indicate, but these are manageable and less common with this technique.

This did not require Ethics approval and there was no grant or industry support for the above.

Introduction

We propose that Total Hip Replacement with correction of fixed flexion deformity of the hip and exaggerated lumbar lordosis will result in relief of symptoms from spinal stenosis, possibly avoiding a spinal surgery. A sequence of patients with this dual pathology has been assessed to examine this and suggest a possible management algorithm.

Introduction

Brachial plexus blocks are used widely to provide intra-operative and post-operative analgesia. Their efficacy is well established, but little is known about discharging patients with a numb or weak arm. We need to quantify the risk of complications for improved informed consent.

Hypothesis

Avascular meniscal tears can be repaired with good clinical outcomes.

Aim

To determine the outcome, the need for revision surgery, quality of life (QOL) of patients and the financial implications of instability following successful closed reduction of dislocation after primary total hip arthroplasty (THA).

Introduction

Review the results of modified Lautenbach procedure (new method) to treat chronic osteomyelitis of the long bones.

This is a study of the quality of outcome of the first 100 patients who received the Twin Peg Oxford Partial knee replacement; which has been designed with a 15 degree extra surface for contact in deep flexion, and two pins for more secure fixation. We measured the outcome in patients with anteromedial osteoarthritis at 2 years after implantation using patient perception outcome measures: the OKS (Oxford Knee Score) and a patient satisfaction questionnaire. We also measured range of motion, the AKS (American Knee Society Score-Objective), the AFS (American Knee Society Score-Functional), and carried out a radiological assessment.

The results showed a mean OKS of 41, a mean AKS of 93, a mean AFS of 84, a mean range of motion of 130 degrees and a 97% satisfaction rate. Results were significantly better in male patients. There were no deaths, infections, dislocations, fractures or revisions. There were no radiolucent lines of 2 mms or more at the femoral bone-cement interfaces.

The introduction of this new version of the Oxford knee shows excellent clinical and radiological results which are at least as good as those seen with the Phase 3 Oxford Partial knee replacement. Small adjustments were made to the minimally invasive approach: a reduced invasive incision for ease of implantation. For those surgeons who are concerned over the risks of femoral loosening with the Phase 3 implant, or desire an improved surface area of contact at high angles of flexion, this Twin Peg Oxford Partial knee replacement offers an excellent alternative.

Simultaneous bilateral Total Knee Arthroplasty (TKA) has been reported to bring greater patient satisfaction, reduce in-patient stay and recovery, with similar outcomes to single sided or staged TKA, but higher complication rates. No validated selection criteria exist.

We report the results of a single surgeon's experience of simultaneous bilateral TKA, using set guidelines for patient selection.

A prospectively maintained database of all simultaneous bilateral TKA performed between 2002 and 2008 was retrospectively analysed, supplemented by case-note review. Outcome measures included length of stay, blood loss and transfusion rates, complications and functionality and validated outcome scores.

40 patients were included, 23 male and 17 female, all with osteoarthritis. Mean age was male 64.9 and female 61.3 years. Mean ASA grade was 1.8. All fitted selection criteria. Mean tourniquet time was right 79.1 minutes and left 83.6 minutes. Preoperative mean haemoglobin level was 141.8 g/dl and mean post operative level of 87.3 g/dl. 13 patients received purely autologous blood transfusion, 16 patients purely allogenic and 6 patients received both. There was 1 intraoperative complication (Medial collateral injury), 3 minor post operative complications which recovered prior to discharge. There were no thromboembolic events or deaths. Mean follow-up was 32.7 months (range 3-79 months). Mean in-patient stay was 7.5 days. Mean range of movement at most recent follow up was right 1.0 to 119.1 degrees flexion and left 1.0 to 120.8 degrees flexion. Mean Knee Society Scores pre- versus post-operatively were: 67 knee/62 function versus 90 knee/82 function. Oxford Knee Scores, Pre- versus post-operatively were: 43 versus 35 (Scoring 0-60, lowest best outcome).

We demonstrate that with appropriate selection criteria, simultaneous bilateral TKA is safe and successful, giving excellent functional outcomes.

Bone marrow is an environment rich in its diversity of cell types and niches. Both hematopoietic and osteogenic stromal cells are present and have been studied extensively. Less is known about the function of one of the most abundant cell types in the bone marrow: adipocytes. There are several hypotheses that have been proposed including: passive role as a space filler; active role in the body's general lipid metabolism; role in providing a localized energy reservoir for emergency situations affecting the bone or hematopoiesis; support of differentiation or function of other cell types (such as bone, endothelial, and other stromal cells).

There are several human pathologies associated with increases in adipocyte hypertrophy or proliferation including changes associated with aging, osteoporosis, and osteonecrosis. The reasons for these changes are poorly understood. One etiology associated with both osteoporosis and osteonecrosis, corticosteroid therapy, has been shown to increase the lipid content of osteoblasts and adipocytes.

With osteonecrosis, several pathogenetic mechanisms involving adipocytes have been proposed:

Mechanical - increased size and number cause increased intraosseous pressure and decreased venous outflow

The possibility that adipocytes may actually play an active role in propagating specific pathologic features has only recently been discussed. This is in part due to our increasing understanding that adipocytes have an endocrine role in metabolism.

Only recently have scientists tried to identify specific cellular mechanisms that may be involved in the pathogenesis of osteonecrosis. Results from these studies will not only contribute to our understanding of the disease of osteonecrosis (and other diseases such as osteoporosis) but will also help us to appreciate the multiple functionalities of the heretofore unappreciated adipocyte.

Aims

To assess the accuracy of posterior and anterolateral methods of injection into the subacromial space (SAS) of the shoulder.

Purpose

Metal-on-Metal (MoM) hip bearings are being implanted in ever-increasing numbers and into ever-younger patients. The consequence of chronic exposure to metal ions is a cause for concern. Therefore, using cytogenetic biomarkers, we investigated a group of patients who have had MoM bearings in situ for in excess of 30 years.

We aimed (1) to determine the factors which influence outcome after surgery for CES and (2) to study CES MRI measurements. 56 patients with evidence of a sphincteric disturbance who underwent urgent surgery (1994-2002) were identified and invited to clinic. 31 MRIs were available for analysis and randomised with 19 MRIs of patients undergoing discectomy for persistent radiculopathy. Observers estimated the percentage of spinal canal compromise and indicated whether they thought the scan findings could produce CES and whether the discs looked degenerate. Measurements were repeated after two weeks.

(1) 42 patients attended (mean follow up 60 months; range 25–114). Mean age at onset was 41 years (range 24–67). 26 patients were operated on within 48 hours of onset. Acute onset of sphincteric symptoms and the time to operation did not influence the outcomes. Leg weakness at onset persisted in a significant number at follow-up (p<0.005). Bowel disturbance at presentation was associated with sexual problems (<0.005) at follow-up. Urinary disturbance at presentation did not affect the outcomes. The 13 patients who failed their post-operative trial without catheter had worse outcomes. The SF36 scores at follow-up were reduced compared to age-matched norms in the population. The mean ODI was 29, LBOS 42 and VAS 4.5.

(2) No significant correlations were found between MRI canal compromise and clinical outcome. There was moderate to substantial agreement for intra- and inter-observer reproducibility.

Background

In suspected scaphoid fracture the initial scaphoid series plain radiographs are 84-94% sensitive for scaphoid fractures. Patients are immobilised awaiting diagnosis. Unnecessary lengthy immobilisation leads to lost productivity and may leave the wrist stiff. Early accurate diagnosis would improve patient management. Although Magnetic Resonance Imaging (MRI) has come to be regarded as the gold standard in identifying occult scaphoid injury, recent evidence suggests Computer Tomography (CT) to be more accurate in identifying scaphoid cortical fracture. Additionally CT and USS are frequently a more available resource than MRI.

We hypothesised that 16 slice CT is superior to high spatial resolution Ultrasonography (USS) in the diagnosis of radiograph negative suspected cortical scaphoid fracture and that a 5 point clinical examination will help to identify patients most likely to have sustained a fracture within this group.

Introduction

Pre-operative urine screening is accepted practice during pre-operative assessment in elective orthopaedic practice. There is no evidence surrounding the benefits, effects or clinical outcomes of such a practice.

Introduction

Elective Orthopaedics has been targeted by the UK Department of Health as a maximum six-month waiting time for operations could not be met. The National Orthopaedic Project was initiated as a consequence and Independent Sector Treatment Centres (ISTCs) and well established private hospitals were utilised to treat NHS long wait patients.

Background

Unicompartmental knee replacements (UKR) converted to total knee replacements (TKR) have often been viewed with scepticism because of the perceived difficulty of the revision and because revision procedures generally do less well than primaries.

Introduction

This study was to investigate the association of developmental dysplasia of the hip (DDH) and primary protrusion acetabuli (PPA) with Vitamin D receptor polymorphisms TaqI and FokI and oestrogen receptor polymorphisms Pvu II and XbaI.

Purpose

To report a retrospective study of 103 cases of primary spinal infection, the largest ever such series from the UK, analysing presenting symptoms, investigations, bacteriology and the results of treatment.

Introduction: Metal-on-metal-hip-resurfacing-arthroplasty (MoMHRA) has been associated with the development of inflammatory pseudotumours(IP), especially in females. IPs have been linked to wear debris, which can be related to metal-ion blood levels. Acetabular component position has been shown to influence wear. We have identified an optimum component orientation minimising IP risk around an inclination/anteversion of 40°/20°±10°. Our aim was to see if this optimal position results in lower metal ions and to identify the boundary of an optimal placement zone for low wear.

Methods: A cohort of 104 patients(60M:44F) with unilateral MoMHRA was studied. Blood tests were obtained at a mean follow up of 3.9 years and serum Co/Cr levels were measured(ICPMS). High metal ion concentrations were defined as Co> 4.1ppb and Cr> 5.2ppb. Radiographic cup inclination/anteversion were measured using EBRA. The differences in ion levels between different orientation zones were investigated. Three orientation zones were defined centered on 40°/20°: Z1-within ±5°, Z2-outside ±5°/within ±10° and Z3-within ±10°.

Results: There was a wide range of cup placements. Females had significantly (p< 0.001) smaller components(mean:51, 44–60) than males(mean: 56, 52–64). Cr levels, but not Co, were higher in females(p=0.002) and those with small femoral components(< 50mm, p =0.03). Patients with cups within Z1 (n=13) had significantly lower Co(p=0.005) and Cr(p=0.001). Males with cups within Z3(n=27) had lower ion levels in comparison to those outside, which were significantly lower for Co(p=0.049) but not Cr(p=0.084). Females had similar ion levels within and out of Z3(Cr/Co: p=0.83/0.84). Co levels were significantly lower in Z1(n=13) in comparison to Z2(n=33)(p=0.048) but Cr levels were not different (p=0.06).

Discussion: MoMHRA cups placed within ±5° of the optimum(40°/20°) had significantly lower metal ions indicating lower wear within this narrow zone. This safe zone, could extend to ±10° for males only. The narrower safe zone coupled with smaller components implanted are possible factors contributing to the increased IP incidence seen in females.

Introduction: Since the introduction of payment by results in the NHS in 2004, the accurate recording of services performed has played a crucial role in reimbursement to hospital trusts by primary care trusts (PCT). Failure to accurately charge for these services causes a shortfall in funding received. Under the new reimbursement system, similar treatments are grouped together under the same tariff and referred to as a Healthcare Resource Group (HRG). Coding is the assignment of procedures to HRG’s. We aim to assess the accuracy of coding performed at our institution and link this directly to the funds received from the PCT. Foot and ankle surgery has a particular interest in coding due to the multiple codes that are utilised to code for one procedure.

Method: We looked at 40 consecutive operations performed at our institution. We compared the codes assigned by the surgeon placing the patient on the waiting list, which were the codes seen directly on the operating list with the final codes given to the PCT. We compared the two codes and looked at the difference in final costing.

Results: There were a total of 75 codes from the 40 operations assigned by the surgeon compared with 103 codes assigned by the coding staff. Although most of the codes were different when the final costing data was generated there was little difference in the overall costs.

Discussion: The importance of accurate coding has become paramount in the current national health service funding. We have shown large discrepancies between the codes the surgeon produces and the final code given to the PCT. Although, in our unit, this has not led to differing final reimbursement figures, it does have the potential to create inaccuracies with a failure to pay for work performed. We will present our data and describe the correct coding for common procedures in foot and ankle surgery, to allow accurate reimbursement.

Introduction: Although good mid-term results have been reported with some metal on metal hip replacements, reported complications due to metal on metal (MOM) related reactions are a cause for concern. We have assessed the clinical outcome and MRI metallic artefact reduction sequence (MARS) findings in a consecutive series of patients with a large head metal on metal hip replacement.

Methods: 62 ASR XL Corail THRs and 17 ASR resurfacings were performed at our hospital between 2005 and 2008. All patients were reviewed and assessed with an Oxford hip score (OHS), a plain radiograph and a MRI imaging was obtained on 76 (96%) hips. Implant position was assessed using Wrightington cup orientation software.

Results: At a mean follow up of 32 months, 9 (15%) ASR XL Corail THRs, and 2(12%) ASR resurfacings had been revised. 10 revisions were performed for MRI confirmed MOM related pathology. Histology confirmed a MOM reaction in all 10 cases.

Of the 76 hips that were MRI scanned, 27 (36%) had typical features of a MOM reaction. These were classified as mild in 10 (13%), moderate in 13 (17%) and severe in 4 (5%).

78 patients completed an OHS and the mean score was 21. The mean OHS was 29 pre-operatively in those that had been revised, 25 in patients with abnormal MRI findings and 20 in those with a normal MRI. 10 patients with abnormal MRIs had a near perfect OHS (15 or less)

Conclusions: The ASR XL Corail THR has an unacceptably high early failure rate. MARS MRI is able to detect metal debris related soft tissue pathology around metal on metal THRs. These lesions are sometimes asymptomatic. We suggest that MARS MRI evaluation should form part of the routine evaluation of all metal on metal THRs, and in particular of this implant.

Purpose: Historically, there have been few surgical options for patients with focal full-thickness cartilage lesions in the knee who have failed or are too advanced in age for biologic resurfacing treatments, yet are also relatively too young or unwilling to undergo conventional total or unicompartmental knee arthroplasty. The UniCAp knee resurfacing arthroplasty provides an option for these patients that is minimally invasive, preserves the menisci and cruciate ligaments, and retains the bony architecture of the knee joint, thereby providing the potential for a rapid recovery to more vigorous activities than might be permitted after conventional knee arthroplasty, while preserving range of motion. The objective of this study was to examine the clinical results of a patient cohort undergoing the UniCAP knee resurfacing in the medial compartment of the knee.

Method: Prospective patients were screened with history and clinical examination, weight-bearing radiographs, and MRI. Patients were offered UniCap knee resurfacing arthroplasty if they had symptomatic full-thickness cartilage lesions in the medial and/or patellofemoral compartments. The cohort included 38 cases in 35 patients who underwent the UniCAP knee resurfacing procedure in the knee with focal medial compartment (with or without patellofemoral) osteoarthritis in the knee joint. In addition, patients were assessed with validated and established outcome scales including the International Knee Documentation Committee Subjective Form, the Knee Injury and Osteoarthritis Outcome Scale, which includes the WOMAC Osteoarthritis Index.

Results: The average age of patients undergoing knee resurfacing was 48.25 years (Range: 23 to 80). There were 24 males and 12 females. Thirty-one patients underwent isolated medial compartment resurfacing and 7 patients received both a medial compartment resurfacing and trochlear resurfacing. Three patients underwent a concomitant ACL reconstruction and 1 patient underwent a concomitant high tibial osteotomy. The mean duration of follow up was 18 months (Range: 12 to 26 months). There was an overall mean improvement from the pre-operative to post-operative scores in the IKDS-SF (P < 0.01), KOOS (all domains, P < 0.01) and WOMAC Index (P < 0.01). There were no major complications such as deep infection, DVT, or implant failure. In addition, there was no evidence of mechanical symptoms/signs or radiographic evidence of loosening at any time point post-operatively.

Conclusion: The short-term results demonstrate that the UniCAP resurfacing arthroplasty in the knee is a viable treatment option for focal full thickness cartilage lesions in the medial compartment of the knee in patients who are no longer candidates for biologic resurfacing procedures and who are also relatively too young or unwilling to undergo conventional total or unicompartmental knee arthroplasty.

Introduction: Metal on metal hip resurfacing arthroplasty-induced pseudotumours are a serious complication, which occur in 1.8% of patients who undergo this procedure in our institution. The aim of this study was to measure the 3D in vivo wear on the surface of resurfacing components revised for pseudotumour, compared to a control group.

Method: Thirty-six hip resurfacing implants were divided into two groups; 18 patients with a clinical and histopathological diagnosis of pseudotumour and 18 controls (revised for femoral neck fracture and infection). Three dimensional contactless metrology (Redlux^™ Ltd) was used to scan the surface of the femoral and acetabular components, to a resolution of 20 nanometers. The location, depth and area of the wear scar were determined for each component. A separate blinded analysis to determine the presence of absence of impingement was performed by one of the authors.

Results: The volumetric wear rate for femoral component of the pseudotumour group was 3.29 mm3/yr (SD5.7) and 0.79 mm3/yr (SD1.2) for the control group (p=0.005). In the pseudotumour group, the volumetric wear rate of the acetabular component was 2.5 mm3/yr (SD6.9) compared to 0.36 mm3/yr (SD0.80) for the control group (p=0.008). Edge-wear was detected in 89% of acetabular components in the pseudotumour group and 21% of those in the control group (p=0.01). Anterior or posterior edge-wear, consistent with impingement was present on the femoral components of 73% of patients in the pseudotumour group and 22% in the control group (p=0.01).

Discussion: This work demonstrates that implants revised for pseudotumour have significantly higher volumetric wear rates than controls. They also have a significantly higher incidence of edge-wear than controls. We suggest that a significant proportion of pseudotumours are associated with high concentrations of metal wear debris; however a minority may result from a hypersensitivity reaction to metal ions.

Introduction: The use of highly cross-linked polyethylene (HXLPE) is now commonplace for total hip arthroplasty, however there is no long-term data to support its use. Hip simulator studies suggest that the wear rate of some types of HXLPE is ten times less than conventional polyethylene (UHMWPE). The outcomes of hip simulator studies are not always reproduced in vivo and there is some evidence that HXLPE wear may increase between 5 and 7 years.

Method: A prospective double blind randomised control trial was conducted using Radiostereometric Analysis (RSA). Fifty-four subjects were randomised to receive hip replacements with either UHMWPE liners or HXLPE liners. All subjects received a cemented CPT stem and uncemented Trilogy acetabular component (Zimmer, Warsaw, IN, USA). The 3D penetration of the head into the socket was determined to a minimum of 7 years.

Results: The total liner penetration was significantly different at 7 years (p=0.005) with values of 0.33 mm (SE 0.05 mm) for the HXLPE group and 0.55 mm (SE 0.05 mm) for the UHMWPE group. The steady state wear rate from 1 year onwards was significantly lower for HXLPE (0.005 mm/yr, SE 0.007 mm/yr) than for UHMWPE (0.037 mm/yr, SE 0.009 mm/yr) (p=0.007). The direction of wear was supero-lateral.

Discussion: We have previously demonstrated that the penetration in the first year is creep-dominated, from one year onwards the majority of penetration is probably due to wear. This study confirms the predictions from hip simulator studies which suggest that the wear rate of this HXLPE approaches that of metal-on-metal and ceramic-on-ceramic articulations. HXLPE may have the potential to reduce the need of revision surgery, due to wear debris induced osteolysis. It may also enable surgeons to use larger couples, thus reducing the risk of impingement and dislocation.

Introduction: Metal on metal hip resurfacing arthroplasty(MoMHRA) is an alternative option to THR in the treatment of young adults with OA. A recognised MoMHRA complication is the development of an inflammatory pseudotumour(IP). Diagnosis is made with the aid of US and/or MRI. To-date, no radiographic indication of the presence of IP has been identified. Neck thinning is a recognised phenomenon in MoMHRA hips not associated with any adverse clinical events. Its pathogenesis is considered multi-factorial. Our aim was to establish whether excessive neck narrowing is associated with the presence of a pseudotumour.

Methods: Twenty-seven hips (26 patients) with IP confirmed clinically, radiologically, intra-operatively and histologically were matched for sex, age, pre-operative diagnosis, component size and follow-up with an asymptomatic MoMHRA cohort (Control n=60). For all patients, prosthesis-neck-ratio(PNR) was measured on plain AP pelvic radiographs post-operatively and at follow-up as previously described and validated.

Results: All IP patients (4M:23F) and all (12M:48F) but two controls had a posterior approach at the time of MoMHRA. Post-operatively, there was no difference in the PNR between the two groups (p=0.19). At an average follow up of 3.5 years (range:0.7–8.3), IP patients(mean 1.26, 1.10–1.79) had a significantly higher (p< 0.0001) PNR in comparison to their controls(mean 1.14, 1.03–1.35). Greater neck narrowing occurred in both genders. IP necks had narrowed by an average of 8% (range:3–23). The degree of neck narrowing was correlated with length of survival of implant (p=0.001).

Discussion: This study shows a strong association between IP and neck narrowing. Processes such as impingement and increased wear are considered to be involved in the pathogenesis of both IP and neck narrowing. Furthermore, the presence of an IP, could lead to altered vascularity via a mass effect and further contribute to neck narrowing. Neck narrowing in symptomatic MOMHRA patients should alert surgeons of the possible presence of IP.

Excessive implant migration and micromotion have been related to eventual implant loosening. The aim of this project is to develop a computational tool that will be able to predict the mechanical performance of a cementless implant in the presence of uncertainty, for example through variations in implant alignment or bone quality. To achieve this aim, a computational model has to be developed and implemented. However, to gain confidence in the model, it should be verified experimentally. To this end, the present work investigated the behavior of a cementless implant experimentally, and compared the results with a computational model of the same test setup.

A synthetic bone (item 3406, Sawbones Europe AB, Sweden) was surgically implanted with a Furlong cementless stem (JRI, Sheffield, UK) in a neutral position and subjected to a compression fatigue test of −200 N to −1.6 kN at a frequency of 0.5 Hz for 50000 cycles. Measurements of the micromotion and migration were carried out using two linear variable differential transducers and the strain on the cortex of the femur was measured by a digital image correlation system (Limess Messtechnik & Software Gmbh).

A three-dimensional model was generated from computed tomography scans of the implanted Sawbone and converted to a finite element (FE) model using Simple-ware software (Simpleware Ltd, Exeter, UK). Face-to-face elements were used to generate a contact pair between the Sawbone and the implant. A contact stiffness of 6000 N/m and a friction coefficient of 0.3 were assigned. The analysis simulated a load of −1.6 kN applied to the head of the implant shortly post implantation. The motions and strains recorded in the experiment were compared with the predictions from the computational model. The micromotion (the vertical movement of the implant during a single load cycle), was measured at the proximal shoulder, at the distal tip of the implant and at the bone-implant interface. The maximum value calculated proximally using FE was 61.3 μm compared to the experimental value of 59.6 μm. At the distal end, the maximum micromotion from FE was 168.9 μm compared to 170 μm experimentally. As a point of reference, some authors have suggested that in vivo, fibrous tissue formation may take place at the bone-implant interface when the micromotion is above 150 μm. The maximum micromotion found computationally at this interface was 99 μm which is below the threshold value defined. The longitudinal strain over the surface of the bone was variable and reached values of up to 0.15% computationally and 0.4% experimentally; this may be related to the coordinate systems used. However, it was noted that digital image correlation identified qualitatively similar strain patterns, and has great potential for measuring low level surface strains on bone.

In conclusion, the good correlation between the computational modelling and experimental tests provides confidence in the model for further investigations using probabilistic analyses where more complex configurations (for example change in implant alignment) can be analyzed.

Background: Postural re-training is one element used in the physiotherapeutic management of spinal disorders. Clinicians need outcome measures that are accurate, reliable and easy to use to monitor effects of treatment and to provide justification for the management of these conditions. This study aimed to assess the reliability of digital video analysis of thoracic, neck and head tilt angles using one measurer within one day.

Methods: Twenty healthy subjects were recruited. L4, C7 spinous processes and tragus were marked on the skin and identified with reflective markers. The subject sat in a relaxed comfortable position in a chair and was video recorded from a lateral view for one minute. The markers were removed and the subject rested, in a chair, for a few minutes. Two further recordings were taken in the same day. Still images were taken at 30seconds of the recording and were analysed using a bespoke programme within MATLAB software. Analysis included Intraclass Correlation Coefficients (ICCs) and Bland Altman plots.

Results: Excellent reliability was ascertained for thoracic, neck and head tilt angles identified by ICC of 0.94 (mean difference 0.34° ±4.7°), 0.91 (mean difference 1.1°±3.7°) 0.84 (mean difference 0.9°±4.9) respectively. All points, except one for neck angle and head tilt angle and two for thoracic angles, were within 95% limits of agreement.

Conclusion: Digital video analysis using MATLAB is a reliable way to measure thoracic, neck and head tilt angles. This is an inexpensive method for measuring posture that could be used in the management of people with spinal disorders.

Conflict of Interest: None

Source of Funding: This study has been financially supported by the Physiotherapy Research Foundation, UK and Research Collaboration Building Capacity Wales (rcbc Wales).

Minimally invasive total knee arthroplasty is purported to have a number of patient benefits: reduced post-operative pain, earlier mobilisation, and shorter in-patient stay.

However, previous literature has identified the existence of a learning curve that may render the procedure unsuitable for low-volume arthroplasty surgeons.

Via retrospective analysis, we set out to compare the incidence of major and minor complications during the first eighty-four minimally invasive total-knee replacements (NexGen; Zimmer UK) undertaken by a single high-volume arthroplasty surgeon starting in April 2004.

The eighty-four patients were sub-divided into four chronological groups (twenty one patients each, designated A, B, C & D respectively). Fifty-three patient records were available for analysis. These comprised: Group A (n=17), Group B (n= 13), Group C (n= 10), and Group D (n=13), with a mean follow-up of 21 months.

Three patients had rheumatoid arthritis, whilst the remaining fifty had osteoarthritis.

There were two major and five minor complications in Group A, one major complication in Group B, one major and one minor complication in Group C, and two minor complications in Group D. Employing a Turkey post hoc ANOVA test, no significant differences were found between the groups when comparing overall complications, or when comparing minor and major complications as separate entities (PASW Statistics 17 for Windows, Chicago, Illinois).

To conclude, although a higher complication rate was observed in this group of patients during the first twenty minimally invasive total knee arthroplasties, this difference was not statistically significant. A follow-up study will analyse the postoperative results of a more recent cohort of patients.

Introduction: The assessment of quality in the provision of healthcare is one of the core features of the National Health Service in the 21st Century. From April 2009 Patient Reported Outcome Measure (PROM) data are being collected for the Department of Health for elective hip and knee arthroplasty using generic and disease specific measures of health status. The perceived uses of these data may be for research, assessment of procedural outcome, measures of health inequalities and to aid commissioning groups in selecting their secondary care providers. Foot and ankle surgery covers a wide spectrum of operative procedures with patient responses less predictable than with major joint arthroplasty. We report the use of a sixteen point satisfaction-based questionnaire in order to investigate the nature of patient outcome after the processes of foot and ankle surgery.

Methods: A prospective series of 100 two-part Visual Analogue Scale (VAS) questionnaires was distributed to patients undergoing elective foot and ankle surgery at the Northern General Hospital under the care of four foot and ankle surgeons over a three-month period. The questionnaires were numbered to allow patient anonymity. The first part of nine questions enquired about pre-operative preparation and information and was distributed before surgery. The second part of seven questions, distributed at the first post-operative clinic sought to investigate their hospital and operative experience. Free text comments were requested in addition to the VAS responses, which were expressed as percentages.

Results: 97% of part one and 85% of part two questionnaires were returned completed. 82% had both parts completed and matched. The day case to inpatient ratio was 55: 45. For part one, all clinically related questions scored more than 90% satisfaction, with only two scores for administration-based questions falling below this level. For part two, satisfaction for clinical questions again scored more than 90% and overall, all scored more than 80% satisfaction. Only 23% of pre-operative and 28% of post-operative questionnaires were returned with free-text comments.

Conclusions: A simple patient satisfaction-based questionnaire may be as useful as existing non-validated generic scoring systems used in foot and ankle surgery when assessing quality in the health service, particularly where regional demographics or referral patterns may be important factors influencing patient outcomes. Active dialogue with the surgical colleges and Department of Health should be pursued to avoid inappropriate outcome measures being imposed in foot and ankle surgery.

Purpose: Medial compartment osteoarthritis (OA) is the most common primary osteoarthritis of the knee, but the treatment of this disease in young patients remains controversial. High tibial osteotomy (HTO), medial unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) are all viable options. Gait analysis is one tool available to clinically assess knee kinematics, and may prove to be a good way of predicting functional outcomes of these different surgical procedures. The purpose of this study was to compare the knee kinematics, function, and quality of life of patients that underwent either a medial opening wedge HTO, UKA, or TKA for primary medial compartment OA.

Method: A matched prospective cohort study of patients between the ages of 45 and 65 who had undergone an HTO, UKA, or TKA for primary medial compartment knee OA was undertaken over a 3-year period. Primary outcome measures were gait variables, namely knee adduction moments, as measured through gait analysis. Secondary measures included quality of life (WOMAC), functional performance tests (six minute walk and timed-up-and-go), self-reported functional ability (LEFS), and general health (SF-36). Gait and functional performance tests were evaluated preoperatively and at 6, 12, and 24 months postoperatively. Self-reported quality of life, function and general health were assessed preoperatively and at 3, 6, 12, and 24 months post-operatively.

Results: Twenty HTOs, 19 medial UKAs, and 17 TKAs were matched for Kellgren-Lawrence grade of medial OA, age at surgery, and body mass index. Significant differences were observed between the three groups in step length and peak adduction moments at 24 months. Significant differences were observed in preoperative WOMAC pain and function scores, KOOS pain scores, and LEFS, but no significantly different outcome measures were observed postoperatively. Lateral Black-burne-Peel and modified Insall-Salvati ratios were the only significant radiographic differences observed between groups at 24 months.

Conclusion: To our knowledge, no gait analysis study exists comparing the medial opening wedge HTO to UKA or TKA. The results of this study suggest that most gait variables except step length and knee adduction moments are similar between groups. Moreover, except for patellar height, there were no major functional or radiographic differences between these groups.

Introduction: One of the main factors in the success of impaction bone grafting (IBG) in revision hip surgery is its ability to resist shear and to form a stable construct. Bone marrow contains multipotent skeletal stem cells and we propose that in combination with allograft will produce a living composite with biological and mechanical potential. In this study we looked at whether coating of the allograft with type 1 collagen followed by seeding with human bone marrow stromal cells (hBMSC) would enhance the grafts mechanical and biological properties.

Methods: A control group of plain allograft and three experimental groups where used to determine the effects that collagen and hBMSC have on IBG. The samples where impacted in standardised fashion previously validated to replicate femoral IBG, and cultured in vitro for 2 weeks. The samples then underwent mechanical shear testing and biochemical analysis for DNA content and Osteogenic activity.

Results: Collagen coating of the allograft prior to seeding with hBMSC significantly enhanced the mechanical properties of the construct compared to the ‘gold standard’ of plain allograft with a 22% increase in shear strength (p=0.002). The collagen coated group also showed increased osteogenic differentiation of the stromal cells (Alkaline Phospatase specific activity: 124 +/− 18.6 vs 54.6 +/− 9.6 nM pNPP/Hr/ngDNA p= < 0.01).

Discussion: This study has shown a role in the improvement of the biomechanical properties of IBG by coating with collagen and seeding with hBMSC. Collagen coating of IBG is a simple process and translation of the technique into the theatre setting feasible. The improvement in shear strength and cohesion could lead to earlier weight bearing for the patients and allow quicker recovery. The therapeutic implications of such composites auger well for orthopaedic applications. We are currently strengthening the above findings with an in vivo study.

Purpose: A long spinal fusion across the thoracolumbar region is sometimes applied in scoliosis. Adjacent level degeneration below these constructs has been documented. Treatment with an artificial disc replacement below the fusion has been proposed to prevent degeneration there. There is currently little data detailing the expected biomechanics of this situation. The objective of this study was to evaluate range of motion (ROM) and helical axis of motion (HAM) changes due to one- and two-level Maverick total disc replacement adjacent to a long spinal fusion.

Method: A multidirectional flexibility testing protocol with compressive follower preload was used to test seven human cadaveric spine specimens (T8-S1). A continuous pure moment ±5.0 Nm was applied in flexion-extension (FE), lateral bending (LB) and axial rotation (AR), with a compressive follower preload of 400 N. The motion of each vertebra was monitored with an optoelectronic camera system. The test was completed for the intact condition and after each surgical technique:

T8-L4 fusion and facet capsulotomy at L4–L5 and L5-S1;

Maverick total disc replacement and fusion with the CD Horizon system was performed. Repeated measures ANOVA was used to analyze changes in ROM and HAM of the L4–L5 and L5-S1 segments.

Results: Following L4-L5 Maverick replacement, L4-L5 ROMs tended to decrease slightly (on average from 6.2°±2.8° to 5.1°±3.8° in FE, 1.1°±1.1° to 0.9°±0.5° in LB and 1.3°±0.9° to 1.0°±0.6° in AR). With two-level Maverick implantation, L5-S1 ROMs tended to increase slightly in FE (from 6.6°±2.6° to 7.1°±3.9°), and to decrease slightly in LB (from 1.5°±0.9° to 1.0°±0.3°) and AR (from 1.5°±1.5° to 1.1°±0.6°), compared to the fused condition. As a trend, HAM location shifted posteriorly in FE and AR, and inferiorly in LB following Maverick replacement. However, neither ROM nor HAM at these two segments showed any significant change due to the implantation of one-or two-level Maverick total disc replacement in any of the three directions.

Conclusion: The present results suggested that lower lumbar segments with Maverick disc replacement exhibited intact-like kinematics in both extent and quality of motion.

Purpose: Spontaneous osteonecrosis of the knee is a potentially greatly debilitating condition. While success has been reported with non-operative treatment of this disorder in its earliest stages, knee arthroplasty is the only viable modality if allowed to progress to condylar collapse. The purpose of this report is to review the etiologic and pathophysiologic principles of spontaneous osteonecrosis of the knee, to present our experience with joint-preserving surgical treatment of this condition, and finally to introduce a treatment algorithm developed based on this knowledge.

Method: Seventeen patients with a clinical and/or radiographic a diagnosis of spontaneous osteonecrosis of the knee, and exclusion of secondary osteonecrosis, who failed non-operative modalities were treated with joint-preserving surgery at a single center between January 2000 and December 2006. Treatment modalities included arthroscopy, and either percutaneous core decompression and/or osteochondral autograft transfer. Three knees were lost to follow-up, leaving 14 knees with a mean follow-up of 37 months (range, 11 to 84 months).

Results: Twelve of 14 knees (86%) had knee joint survival with a mean Knee Society Score of 80 points (range, 45 to 100 points) at final follow-up. One patient was treated with serial core decompression followed by osteochondral transfer, and was included in both groups. Six of 7 patients (86%) treated with core decompression alone had a successful clinical outcome, as did 7 of 8 patients (87%) treated with osteochondral autograft transfers. Two patients (14%) progressed to condylar collapse, and were treated with total knee arthroplasty with successful results.

Conclusion: Based on these results, we propose a treatment algorithm that begins with non-operative treatment, followed by joint-preserving surgery consisting of arthroscopy, core decompression, and/or osteochondral autograft transfer. Although our sample size is small, the results suggest that this proposed treatment algorithm can successfully postpone the need for knee arthroplasty in selected patients with pre-collapse spontaneous osteonecrosis of the knee.

Purpose: Females are at greater risk for anterior cruciate ligament (ACL) injury than males. Soccer may be a significant risk factor for ACL injury in adolescent females. ACL injury has significant consequences, including early onset of osteoarthritis. The purpose of the study was to determine

the number of ACL reconstruction surgeries performed on females between the ages of 13–18 inclusive in the Capital Health (CH) region from December 2000 to November 2005, and

Secondly, we describe factors relating to the mechanism of injury.

Method: Utilizing regional administrative data, we performed a standardized chart review and telephone interviews with female adolescents who underwent ACL reconstruction in the aforementioned time period. Information gathered included:

Age at reconstruction procedure.

The Alberta Soccer Association provided the number of registrants in indoor and outdoor seasons over the same time period.

Results: 2,824 ACL reconstruction operations were performed between December 2000 and November 2005. Reconstructions in females took place at an earlier age than in males. There were 266 ACL reconstructions in 256 adolescent females, of which 253 charts were available for review. One hundred and eleven (44%) knees were injured during soccer play. Seven patients with eight ACL reconstructions who injured their ACL playing soccer could not be located. ACL injuries occurred during indoor soccer in 52 (51%) cases despite higher registration in outdoor soccer during the same time-frame. 77 (74%) subjects played competitively and 81 (79%) subjects played two or more times/week.

Conclusion: Approximately 10% of ACL reconstructions were performed on adolescent females. Nearly 50% of ACL injuries occurred during soccer play, with a similar number seen in indoor versus outdoor play. Study limitations include the use of administrative data to assess the number of ACL reconstructions rather than ACL injuries. An awareness of the propensity of knee injuries in female soccer players is important. With the increased participation of young females in soccer and the serious lifelong implications of ACL rupture, prevention and training should be improved to lower the incidence of injury.

Metal on metal hip resurfacing (MMHR) is a popular procedure for the treatment of osteoarthritis in young patients. Several centres have observed masses, arising from around these devices, we call these inflammatory pseudotumours. They are locally invasive and may cause massive soft tissue destruction. The aim of this study was to determine the incidence and risk factors for pseudotumours that are serious enough to require revision surgery.

In out unit, 1,419 MMHRs were performed between June 1999 and November 2008. All revisions were identified, including all cases revised for pseudotumour. Pseudotumour diagnosis was made by histological examination of samples from revision. A Kaplan-Meier survival analysis was performed, Cox regression analysis was used to estimate the independent effects of different factors.

The revision rate for pseudotumour increased with time and was 4% (95% CI: 2.2% to 5.8%) at eight years. Female gender was a strong risk factor: at eight years the revision rate for pseudotumours in men was 0.5% (95% CI 0% to 1.1%), in women over 40 it was 6% (95% CI 2.3% to 10.1%) and in women under 40 it was 25% (95% CI 7.3% to 42.9%) (p< 0.001). Other factors associated with an increase in revision rate were, small components (p=0.003) and dysplasia (p=0.019), whereas implant type was not (p=0.156).

We recommend that resurfacings are undertaken with caution in women, especially those younger than 40 years of age, but they remain a good option in men. Further work is required to understand the patho-aetiology of pseudotumours so that this severe complication can be avoided.

Background: PIP joint surface replacement has been shown to be effective in the treatment of arthritis. We performed a retrospective review to evaluate the clinical results and functional outcome of pyrocarbon proximal interphalangeal joint replacement, motion preserving and function in selected patients.

Method: The patients who underwent pyrocarbon PIP joint arthroplasty by the two senior authors were reviewed. Clinical assessment included range of motion, degree of pain and deformity pre and post operatively. Independent functional scores were collected. Radiographs were reviewed for evidence of loosening, fracture and dislocation. Patient overall satisfaction was assessed.

Results: 25 patients had 27 pyrocarbon PIP joint replacements between 2004 and 2008. Of these patients, there were 21 female (84%) and 4 male (16%) with average age of 62.5 (43–78). Indications for surgery were pain and loss of function. The preoperative diagnosis was post traumatic osteoarthritis in 9 (33.3%) and primary osteoarthritis in 18 (66.7%). The average arc of motion preoperatively was 42.3 (5–60), and the average postoperative one was 74.3 (45–100). Pain was relieved in majority of patients. 23 patients (92%) were satisfied completely with the procedure. Pain was relieved in the majority of cases and we had 2 dislocations requiring revision to silicone joint replacement and 2 adhesions/stiffness requiring tenolysis. There were no infections.

Conclusion: Our experience of pyrocarbon PIP joint replacement over the 4 years showed this implant is useful for relief of pain and function. A technically demanding procedure, it improves arc of motion, corrects deformity and achieves satisfactory function. We had 7 % revision rate and longer term follow-up is required.

Purpose: The functional consequences of femoral nerve resection during soft tissue sarcoma management are not well described. Sciatic nerve resection with a sarcoma, once considered an indication for amputation, is now commonly performed during limb salvage. We compared the functional outcomes of femoral and sciatic nerve resections in patients undergoing wide resection of soft-tissue sarcomas.

Method: The prospectively collected database from a tertiary referral center for sarcomas was retrospectively reviewed to identify patients with resection of the femoral or sciatic nerve performed during wide excision of a soft tissue sarcoma. Patient demographics, treatment, complications and functional outcomes were collected.

Results: Ten patients with femoral nerve resections were identified, all women, aged 47 to 78, with large soft tissue sarcomas of varied subtypes. All patients received adjuvant radiotherapy, most pre-operatively. Six patients developed fractures with long-term follow-up, only two of which were in the prior radiation field. Musculoskeletal Tumor Society (MSTS) 1987 scores demonstrated one excellent, 4 good, and 5 fair results. MSTS 1993 scores averaged 71.4 ± 17.2 percent and Toronto Extremity Salvage Scores (TESS) averaged 61.7 ± 21.8. There were no significant differences between the functional scores for patients with femoral or sciatic nerve resections (P=1.0).

Conclusion: Femoral nerve resection appears more morbid than anticipated. The falls to which patients were prone, even years after surgery, subject them to ongoing long-term risks for fractures and other injuries. Nerve-specific functional outcomes should be considered when counseling patients prior possible resection of the femoral nerve for involvement by a soft tissue sarcoma.

Purpose: We hypothesized that glenohumeral joint stability will decrease with increasingly larger humeral head defects.

Method: Humeral head defects were created in 9 cadaveric shoulders to simulate Hill Sachs defects. Defects represented 1/8, 3/8, 5/8, and 7/8 of the radius of the humeral head. Secondary factors included abduction angles of 45 degrees and 90 degrees, and rotations of 40 degrees internal, neutral, and 40 degrees external. Specimens were tested at each defect size sequentially from smallest to largest and at each of 6 conditions for all abduction and rotation combinations. Using a 6 degree-of-freedom robot, the humeral head was translated at 0.5 mm per second until dislocation in the anteroinferior direction at 45 degrees to the horizontal glenoid axis.

Results: ANOVA demonstrated significant factors of rotation (p< 0.001) and defect size (p< 0.001). In 40 degrees external rotation, there was significant reduction of distance to dislocation compared with neutral and 40 degrees internal rotation (p< 0.001). The 5/8 and 7/8 radius osteotomies demonstrated decreased distance to dislocation compared to the intact state (p< 0.05 and p< 0.001 respectively). There was no difference found between abduction angles. Post hoc analysis determined significant differences for each arm position. There was decreased distance to dislocation at the 5/8 radius osteotomy at 40 degrees external rotation with 90 degrees of abduction (p< 0.05). For the 7/8 radius osteotomy at 90 degrees abduction, there was decrease distance to dislocation for neutral and 40 degrees external rotation (p< 0.001). For the same osteotomy at 45 degrees abduction, there was decreased distance to dislocation at 40 degrees external rotation (p< 0.001). With the humerus internally rotated, there was never a significant change in the distance to dislocation.

Conclusion: Glenohumeral stability decreases at a 5/8 radius defect and was most pronounced in 40 degrees external rotation and at 90 degrees abduction. At a 7/8 radius humeral defect, there was further decrease in stability at both neutral and external rotation. Internal rotation always maintained baseline glenohumeral stability.

Purpose: Few functional outcomes of total femoral endoprosthetic replacement (TFEPR) using contemporary modular systems are available. We compared functional results between TFEPR patients receiving fixed- and rotating-hinge knee componentry following oncologic resections.

Method: Eighteen TFEPR patients were identified from a prospectively gathered sarcoma database. Six were secondary procedures and 12 primary. Four patients had metastatic carcinoma, 8 osteosarcoma, 4 non-osteogenic spindle cell sarcomas of bone, 1 Ewing’s sarcoma, and 1 femur-invading soft-tissue sarcoma. All reconstructions used modular implants from a single company. Proximally, all were bipolar hip hemiarthoplasties, 12 including abductor reattachment. Distally, 8 had fixed- and 10 had rotating-hinge knee componentry. Toronto Extremity Salvage Score (TESS), and both Musculoskeletal Tumor Society Scores (MSTS) were compared between fixed- and rotating-hinge groups using the Mann-Whitney test.

Results: Complications included 1 hip dislocation, 1 femoral malrotation, and wound problems requiring 3 debridements and 1 amputation. One metastatic carcinoma patient developed local relapse. Follow-up averaged 4 years (range 1 month to 14 years). At latest follow-up, 10 patients had died of disease. Eight remained alive, 6 disease-free, 2 with distant disease. Among patients surviving 6 months, 6 used no assistive devices, 5 used a single cane, and 4 were wheelchair bound, each at least partly due to distant disease progression. TESS averaged 74.5±17.4, MSTS1987 25.2±4.4; and MSTS1993 58.6±22.9 among the 12 patients for whom functional results were available from latest follow-up. No statistically significant differences or even trends were detected between fixed-hinge and rotating-hinge patients (lowest p = 0.755), but both instability problems were in the rotating-hinge group.

Conclusion: While both rotating- and fixed-hinge TFEPR reconstructions may function well, consideration should be given to fixed-hinge knee reconstruction when massive myectomies or poorer conditioning make hip and knee stability a primary concern in the short-term.

Objectives: We aimed to assess the incidence of requirement for shoe raises for a leg length discrepancy (LLD) after total hip replacement (THR). We also assessed the patient satisfaction with, and continued use of shoe raises for symptomatic LLD after THR.

Methods: We searched the orthotics records at our institution to identify all patients who had required a shoe raise for symptomatic LLD after primary unilateral total hip replacement between January 2003 and October 2008. 75 patients were identified. 72 were still alive. In the same period 4270 primary hip replacements were carried out at the institution. A questionnaire was sent out to all living patients. Patient details (including satisfaction) and operative details were recorded. Pre-operative and post-operative radiological measurements of leg length discrepancy (LLD) were performed.

Results: The incidence of requirement of a shoe raise for LLD after THR at our institution was 1.8%. 68% were women. 84% of questionnaires were returned. 31% had stopped using their shoe raise completely. Two-thirds of patients found the raise improved their symptoms of a LLD. Symptoms causing dissatisfaction with the shoe raise included new or worsening back pain, limp, uneven walking, self awareness, need to adjust trouser length, pain in other hip, discomfort while walking, and difficulty buying shoes. Patient overall satisfaction with their THR was poor in the patients who were dissatisfied with the shoe raise, but was good in those who found the raise useful.

Conclusion: About 2% of patients may require a shoe raise for symptomatic LLD after THR. Of these 65% will find the shoe raise helpful. Patient with a LLD after a THR that is not helped by a shoe raise are very dissatisfied. It is important that surgeons should take great care to avoid causing a LLD after THR as it can be a cause of very low patient satisfaction.

Introduction: Pseudotumours (soft-tissue masses relating to the hip joint) following metal-on-metal hip resurfacing arthroplasty (MoMHRA) have been associated with elevated serum and hip aspirate metal ion levels, suggesting that pseudotumours occur when there is increased wear. This study aimed to quantify in vivo wear of implants revised for pseudotumours and a control group of implants revised for other reasons of failure.

Methods: A total of 30 contemporary MoMHRA implants in two groups were investigated in this Institutional Review Board approved study:

8 MoMHRA implants revised due to pseudotumour;

The linear wear of retrieved implants was measured using a Taylor-Hobson Roundness machine. The average linear wear rate was defined as the maximum linear wear depth divided by the duration of the implant in vivo.

Results: In comparison with the non-pseudotumour implant group, the pseudotumour implant group was associated with:

significantly higher median linear wear rate of the femoral component: 8.1um/year (range 2.75–25.4um/year) vs. 1.79um/year (range 0.82–4.15um/year), p=0.002; and

Similarly, differences were also measured in absolute wear values. The median absolute linear wear was significantly higher in the pseudotumour implant group:

21.05um (range 2.74–164.80um) vs. 4.44um (range 1.50–8.80um) for the femoral component, p=0.005; and

Wear on the acetabular cup components in the pseudotumour group always involved the edge, indicating edge-loading of the bearing. In contrast, edge-loading was observed in only one acetabular component in the non-pseudotumour group of implants. The deepest wear was observed well within the bearing surface for the rest of the non-pseudotumour group. The difference in the incidence of edge-loading between the two groups was statistically significant (Fisher’s exact test, p=0.03).

Discussion: Significantly greater linear wear rates of the MoMHRA implants revised due to pseudotumour support the in vivo elevated metal ion concentrations in patients with pseudotumours. This study provides the first direct evidence to confirm that pseudotumour is associated with increased wear at the MoM articulation. Furthermore, edge-loading with the loss of fluid film lubrication may be the dominant wear generation mechanism in patients with pseudotumour.

The National Institute for Clinical Excellence, UK published guidelines in 2007 encouraging the use of low molecular weight heparin (LMWH) joint replacement surgery. Subsequently, our hospital adopted these guidelines in the treatment of total hip replacements. This study is based on our prospective database of total hip replacements between 2005 and 2009 and compares the complication and mortality rates pre- and post institution of the NICE guidelines.

We analysed prospectively collected data on 686 patients who underwent a primary total hip replacement done by a single surgeon between January 2005 and April 2009. We compared the incidence of mortality, pulmonary embolism, myocardial infarction and intracranial bleeding between the two groups. Prior to the guidelines, all patients were treated for the duration of their admission with 75mg aspirin followed by 4 weeks after discharge. Subsequent to the guidelines, the treatment changed to 40mg of LMWH (Clexane) while an inpatient with aspirin being prescribed for 4 weeks on discharge. Patients unable to tolerate aspirin were treated with low molecular weight heparin. High risk patients (previous pulmonary embolism, previous deep vein thrombosis, family history) were treated with 6 weeks of warfarin. Each patients was reviewed at 8 weeks and 6 months following surgery, and adverse incidents were documented at each review or incident.

Results: 686 patients were identified from the study – 328 pre and 358 post implementation of the NICE guidelines. In the pre-guideline group the mortality was 0.6%, with the incidence of pulmonary embolism being 0.3%, myocardial infarction 0.9% and intracranial bleed 0.3%. Both complications of myocardial infarction occurred early in the post-operative stage and were fatal. The post-guideline group had a mortality rate of 0.2%, with the incidence of pulmonary embolism being 0.2% and intracranial bleeding 0.2%. No myocardial infarctions were noted in this group. The single death was as a result of an intracranial bleed. The was no significant statistical difference in the incidence of mortality, pulmonary embolism, myocardial infarction or intracranial bleeding between the two groups (p value > 0.05, 95% confidence interval). There were no complications in the warfarinised patients of which there were equal numbers in both groups (16).

Conclusion: This study has shown that the change in thromboprophylaxis has not had a significant effect on complication rates in primary total hip replacements and that our mortality rate (0.4%) compares favourably with recent literature. The lack of complications in the war-farinised group probably reflects that high risk patients were identified in the screening process and commenced on warfarin early in the post operative period. Note must be made of the single death due to an intracranial bleed while on low molecular weight heparin.

Background: Thumb carpalmetacarpal joint (CMCJ) osteoarthritis has been treated using various combinations of resection, interposition and replacement arthroplasties. The procedure of choice for various stages of CMCJ osteoarthritis remains controversial. This study compares the short term outcomes of trapeziectomy alone and trapeziectomy with PI2 implantation.

Methods: A cross-sectional observational study involving 33 patients (36 thumbs). 18 thumbs had trapeziectomy alone and 18 had trapeziectomy and PI2 implantation. Underlying indication was osteoarthritis in 35 thumbs and trauma in one thumb. Preoperative radiological assessment using the Eaton and Glickel grading for CMCJ osteoarthritis and clinical review including DASH and SF-36 score was performed at a mean follow-up of 18 months. Preoperative and postoperative pain level was assessed using Visual Analogue Scale (VAS) and satisfaction of the surgery using the Likert 5-point scale.

Results: There were 30 women and 3 men. The average age at follow up was 61 years (range 45 to 75). There was no significant difference between the two groups regarding age, duration of symptoms, and stage of disease, preoperative pain score and handedness. The mean DASH score at follow up was 26.8 for trapeziectomy alone group and 35.4 for the PI2 arthroplasty group. Preoperative to postoperative VAS for pain showed an improvement from fair to excellent in 60% of patients in trapeziectomy alone group and 30% of the patients in the PI2 arthroplasty group. There was no significant difference in the SF-36 scores between the two groups in all health domains. 6 out of 16(38 %) patients in the PI2 group had multiple surgeries mainly due to dislocation or subluxation of the implant. The overall Likert 5-point scale scores were highest for trapeziectomy alone group with 70% very satisfied compared to 40% in the PI2 arthroplasty group.

Conclusion: The early results of pyrocarbon PI2 arthroplasty show a high complication rate compared to simple trapeziectomy. The high rates of subluxation and dislocation observed in the early cohort resulting in multiple surgeries may be attributed to steep learning curve of the surgical technique and creation of a shallow groove for the implant. This may have contributed to the low satisfaction levels observed in PI2 arthroplasty group. Simple trapeziectomy provides satisfactory outcome in more than 80% of the patients.

Introduction: The use of second generation highly cross-linked polyethylene (HXLPE) is now commonplace for total hip arthroplasty, however there is no long-term data to support its use. Hip simulator studies suggest that the wear rate of HXLPE is ten times less than conventional polyethylene (UHMWPE). The outcomes of hip simulator studies are not always reproducible in vivo. Long term clinical data is required, as there is emerging clinical data, which suggests that some types of second generation HXLPE may have increased wear after 5 years.

Method: A prospective double blind randomised control trial was conducted using Radiostereometric analysis (RSA). Fifty-four subjects were randomised to receive hip replacements with either UHMWPE liners or HXLPE liners. All subjects received a cemented CPT stem and uncemented Trilogy acetabular component (Zimmer, Warsaw, IN, USA). The 3D penetration of the head into the socket was determined to a minimum of 7 years.

Results: The total liner penetration was significantly different at 7 years (p=0.01) with values of 0.33mm (SD 0.17mm) for the HXLPE group and 0.51mm (SD 0.14mm) for the UHMWPE group. The steady state wear rate from 1 year onwards was significantly lower for HXLPE (0.003 mm/yr, SD 0.04 mm/yr) than for UHMWPE (0.03 mm/yr, SD 0.03 mm/yr) (p=0.01). The direction of wear was in the antero-medial direction in both groups.

Conclusion: We have previously demonstrated that the penetration in the first year is creep-dominated, from one year onwards the majority of penetration is due to wear. The wear rate of this second generation HXLPE approaches that of metal on metal bearings. Second-generation HXLPE may have the potential to reduce the risk of revision surgery, due to wear debris induced osteolysis.

Introduction: Metal on metal hip resurfacing arthroplasty-induced pseudotumours are a serious complication, which occur in 4% of patients who undergo this procedure. The aim of this study was to measure the 3D in vivo wear on the surface of resurfacing components revised for pseudotumour, compared to a control group.

Method: Thirty-nine hip resurfacing implants were examined; these were sourced from our institutions prosthesis retrieval bank. They were divided into two groups; 22 patients with a clinical and histopathological diagnosis of pseudotumour and 17 controls. Patient demographics and time to revision were known. Three dimensional contactless metrology (Redlux™ Ltd) was used to scan the surface of the femoral and acetabular components, to a resolution of 20 nanometers. The location, depth and area of the wear scar was determined for each component. Volumetric wear was determined, along with the presence of absence of edge-loading. A separate blinded analysis to determine the presence of absence of impingement was performed by one of the authors. ANOVA was used to test for differences in wear and Fishers Exact test was used to compare the incidence of edge-loading between the groups.

Results: The volumetric wear rate for femoral component of the pseudotumour group was 4.7mm3/yr (SD3.5) and 1.7 mm3/yr (SD1.5) for the control group (p=0.03). In the pseudotumour group, the volumetric wear rate of the acetabular component was 3.5 mm3/yr (SD3.6) compared to 0.02 mm3/yr (SD0.07) for the control group (p=0.01). Edge-loading was detected in 74% of acetabular components in the pseudotumour group and 22% of those in the control group (p=0.01). Anterior or posterior edge-loading, consistent with impingement was present on the femoral components of 73% of patients in the pseudotumour group and 22% in the control group (p=0.01).

Discussion: This work demonstrates that implants revised for pseudotumour have significantly higher volumetric wear rates than controls. They also have a significantly higher incidence of edge-loading and impingement than controls. Edge-loading significantly increases wear. We suggest that pseudotumours are caused by high concentrations of metal wear debris, which have been shown to have a toxic effect on osteocytes and macrophages. This is the one of the first studies to demonstrate a clear link between pseudotumours and increased bearing surface wear. It is also the first to demonstrate that edge-loading, due to impingement, occurs in a significant number of patients who develop this condition. Improved implantation techniques and resurfacing designs may help avoid this serious complication of hip resurfacing.

Introduction: Metal-on-metal hip resurfacing arthroplasty (MoMHRA) has gained popularity as an alternative to THR for younger patients with osteoarthritis. A growing concern has been the association of MoMHRA with the development of inflammatory pseudotumours (IP), especially in women. These have been linked to metal-on-metal wear, which can be related to metal ion concentrations. Elevated metal wear debris levels may result from impingement, rim contact and edge loading. Head-neck ratio (HNR) is a predetermining factor for range of movement and impingement. Neck thinning is a recognised phenomenon post-MoMHRA and we have found an association of IP with increased neck thinning based on a case control study. Our aims were to identify HNR changes a hip undergoes when resurfaced and at follow up; and whether greater neck thinning at follow-up could be associated with the presence of elevated metal ions.

Methods: A cohort of 91 patients (57M:34F) with unilateral MoMHRAs were included in this study. Blood tests were obtained at a mean follow up of 3.9 years (range 1.7–7 years) and serum (Co:Cr) ion levels were measured (ICPMS). High metal ion concentrations were defined as Co> 4.1ppb and Cr> 5.2ppb. For all patients, head-neck ratio (HNR) was measured on plain anterio-posterior pelvic radiographs pre-operatively, immediately post-operatively and at follow-up.

Results: Female patients had significantly bigger HNR pre-op (mean=1.35, range:1.22–1.64) compared to males(mean=1.22, range:1.05–1.38) (p< 0.01). Immediately post-op, female HNRs (mean: 1.26, range: 1.14–1.34) were not different to male patients(mean=1.24, range=1.11–1.38) (p=0.11). At follow-up HNR was once again significantly bigger (p< 0.01) in females (mean=1.35, range: 1.21–1.49), compare to males (mean=1.27, range:1.11–1.38). HNR alterations with operation (p=0.00) and at follow-up (p< 0.01) were significantly bigger in female patients. Furthermore, there was a significant correlation between high ion levels and HNR change at follow-up for both Co (p=0.02) and Cr (p< 0.01).

Conclusion: This study identified gender-specific changes in HNR that resurfaced hips undergo, not previously documented. Female hips have greater HNR pre-operatively, compared to male hips, and appear to be biomechanically disadvantaged when resurfaced. A decrease in HNR with resurfacing could result in impingement and lead to processes, known to be more prevalent in females, such as neck thinning, increased wear and IP development. In addition, we highlight a correlation between high ion levels and greater neck thinning at follow-up. Increased neck thinning in symptomatic MoMHRA hips could be secondary to increased wear and should be investigated further radiologically for the presence of IP.

From 2004–2006, in an attempt to reduce the waiting time for patients listed for total knee and total hip arthroplasty at Cardiff and Vale NHS Trust, 156 total hip replacements (THRs) were performed by Swedish Orthopaedic surgeons at an NHS treatment centre in England.

All patients were contacted and invited to a review appointment with a Consultant specialising in hip and revision hip replacement. Oxford Hip Scores and clinical and radiographic evaluation were performed. Patients who declined an appointment were sent a postal questionnaire. Radiographs were analysed for component position, radiolucent lines, medial floor breach, leg length discrepancy.

One hundred and thirteen hips were reviewed at a mean 23 month follow-up. The mean Oxford score was 26. Mean age at surgery was 69. Cemented THR was performed in 104 hips; hybrid in 7; cementless in 2. The Exeter stem and Cenator cemented cup were used in the majority of cases. 16% had acetabular inclination greater than 55 degrees. Radiolucent lines around the cup were seen in 76/113 hips. Femoral stem position was greater than 4 degrees varus in 47/113. Medial floor breach seen in 13/113. 10/113 had leg length discrepancy > 1cm. There were 3 dislocations, 1 femoral fracture, 1 pulmonary embolus, 3 deep infections, 2 superficial infections.

Revision surgery has been performed in 18/113 – the majority for a painful loose acetabular component. A further 5/113 have been recommended for surgery. The further surgery rate was 12% at 2 year follow-up.

The revision rate far exceeds the 0.5% 5-year failure rate reported in the Swedish Registry for the components used. This initiative has left a legacy of unhappy patients, and increased the workload required in our unit to correct the problems. The lack of long-term ownership of patients may be an important factor.

Thirty-five patients were followed prospectively from their referral to the Problem Fracture Service with chronic osteomyelitis of diaphyseal bone between November 1994 and June 1999.

The patients were treated using a closed double-lumen suction irrigation system following reaming and arthroscopic debridement of the intramedullary canal; this is a modified system based on the work of Charles Lautenbach. Results of these procedures were regularly followed up in clinic, and between June and July 2007 the whole cohort was reviewed via postal questionnaire, telephone and case note review.

At a mean follow up of 101 months, 26 were living with no evidence of recurrence, 4 had died of unrelated causes with no evidence of recurrent infection. Four patients had persisting problems with sinus discharge requiring intermittent antibiotic therapy and 1 patient had his limb amputated for recurrent metaplastic change.

These results gave this cohort an 86% clearance of infection, with recurrence in 12%, which is comparable to the Papineau and Belfast techniques with significantly less surgical insult to the patient.

Introduction: Giant cell tumour of bone (GCTB) is an expansile osteolytic tumour of bone which contains numerous osteoclast-like giant cells. GCTB is a locally aggressive tumour which can cause extensive bone destruction that can be difficult to control surgically, up to 35% of cases recurring after simple curettage. Bisphosphonates are anti-resorptive agents that have proved effective in the treatment of a number of osteolytic conditions.

Methods: This study reports results from four European centres where bisphosphonates are being used to treat problematic GCTBs. Details of treatment with bisphosphonates of 25 cases of primary, recurrent and metastatic GCTBs was assessed clinically and radiologically.

Results: Most primary/recurrent tumours did not exhibit progressive enlargement and, in some cases, both primary and metastatic GCTBs showed a degree of radiological improvement following treatment. Some patients also noted relief of pain following treatment. In a few cases, no apparent treatment effect was noted and there was disease progression. Several inoperable large spinal/pelvic GCTBs remained stable in size following treatment.

Discussion: Our findings provide preliminary evidence for the use of bisphosphonates to inhibit the progressive osteolysis associated with GCTB. These agents had a beneficial clinical and/or radiological effect in most cases. This study reports results from four European centres and highlights the fact that these centres are all employing different clinical indications and different regimes of bisphosphonate treatment. Bisphosphonates have significant side effects and indications for treatment and standardisation of drug type and dosage regimes (and measurement of agreed outcome measures to determine treatment efficacy) should be established for the use of these agents to control GCTB tumour growth and osteolysis.

We aimed to evaluate the effects of implementing blood conservation strategies on transfusion requirements in adult patients undergoing scoliosis correction surgery. We retrospectively studied 50 consecutive adult patients who underwent scoliosis correction surgery (anterior, posterior or combined) between 2003 and 2007. All patients had a standard transfusion protocol. Age, BMI, pre and post operative haemoglobin, levels fused, duration of surgery, hospital stay, anti-fibrinolytics used and blood transfused was noted.

50 patients with mean age 24.6 years and mean BMI 21.9 kg/m2 were studied. 14 patients had anterior surgery, 19 patients had posterior surgery and 17 had combined anterior and posterior procedures. Mean number of levels fused was 9.5 (6–15) and mean duration of surgery was 284.6 minutes (135–550 minutes). Antifibrinolytics were used in 31 patients (62%), Aprotinin in 21(42%) and Tranexamic acid in 10 (20%). Mean blood loss in patients who received anti fibrinolytics was 530mls while mean blood loss in the other patients was 672mls. (p< 0.05). Blood transfusion was not required in any of the patients undergoing anterior correction only while 7 patients (41%) undergoing anterior and posterior correction and 3 patients (15.8%) undergoing posterior correction only required blood transfusion. Mean volume of cell saved blood re-transfused was 693.8 mls and mean hospital stay was 9.2 days. Mean pre-op haemoglobin was 13.2 g/dl (10.4–17.4) and mean post-op haemoglobin was 10.7 g/dl (7.7–15). 4 patients (8%) required intra and post-operative blood transfusion while 6 patients (12%) required blood transfusion postoperatively.

In conclusion, the use of anti-fibrinolytics like Aprotinin and Tranexamic acid reduces blood loss in scoliosis surgery. In the current scenario, with Aprotinin no longer available for use, our study would recommend the use of Tranexamic acid alongwith other blood conservation measures. In our unit we do not have blood cross matched for anterior surgery alone.

Roentgen Stereophotogrammetric Analysis (RSA) can predict long-term outcome of prostheses by measuring migration over time. The Exeter femoral stem is a double-tapered highly polished implant and has been shown to subside within the cement mantle in 2 year RSA studies. It has a proven track record in terms of long-term survivorship and low revision rates. Several studies have demonstrated excellent clinical outcomes following its implantation but this is the first study to assess stem migration at 10 years, using RSA.

This is a single-centre study involving 20 patients (mean age: 63 years, SD=7) undergoing primary total hip replacement for degenerative osteoarthritis using the lateral (Hardinge) approach. RSA radiographs were taken with the patient bearing full weight post-operatively, at 3, 6, 12 months and at 2, 5 and 10 years follow-up. The three-dimensional migration of the Exeter femoral stem was determined.

The mean Oxford Hip Score at 10 years was 43.4 (SD=4.6) and there were no revisions. The stems subsided and rotated internally during a 10-year period. The mean migrations of the head and tip of the femoral stem in all three anatomic directions (antero-posterior, medio-lateral & supero-distal) were 0.69 mm posterior, 0.04 mm lateral and 1.67 mm distal for the head and 0.20 mm anterior, 0.02 mm lateral and 1.23 mm distal for the tip. The total migration at 10 years was 1.81 mm for the head and 1.25 mm for the tip.

The Exeter femoral stem exhibits migration which is a complex combination of translation and rotation in three dimensions. Comparing our 10 year with our previous 2 year migration results, the Exeter stems show continued, but slow distal migration and internal rotation. The subsidence continues to compress the cement and bone-cement interface which maintains secure fixation in the long term.

Introduction: Revision hip surgery is predicted to rise significantly over the coming decades. There is therefore likely to be an increasing need to overcome the large bone loss and cavitatory defects encountered in failed primary hip replacements. Impaction bone grafting (IBG) is a recognised technique for replacing lost bone stock. Achieving optimal graft impaction is a difficult surgical skill with a significant learning curve, balancing the need to achieve sufficient compaction to provide primary stability versus the need to keep impaction forces to a minimum to prevent iatrogenic fracture. In this study we have developed a revision acetabular model to test the hypothesis that the use of vibration and drainage with a new custom made perforated tamp could reduce the peak stresses imparted to the acetabulum during the impaction process and also improve the reliability and reproducibility of the impaction technique

Methods: Composite Sawbone hemi Pelvis models were used, with identical contained cavitatory defects created (Paprosky Type 2a). A strain gauge was attached to the medial wall of each hemi pelvis. A custom set of IBG tamps were made, and coupled a pneumatic hammer used to generate the vibrations. A standard impaction technique was used for the control group and the new vibration impaction for the experimental group. The cavity was progressively filled with morsellised allograft in 6 set steps for both groups with strain gauge readings taken during all impaction to monitor peak stresses. A standard Exeter Contemporary cup was then cemented into the graft bed for both groups. The models were mechanically loaded according to the protocol developed by Westphal et al at the angle of the joint reaction force during heel strike for a total of 50 000 cycles. 3D assessment of any micro motion post mechanical testing and degree of graft compaction was done with high resolution micro CT.

Results: Vibration impaction lead to a significant reduction in the peak stresses during the impaction process throughout the 6 steps (e.g. Step 1: 34.6 vs 110.8 MPa p=0.03). There was also far less variability in the peak stresses in the vibration group compared to standard impaction both in sequential impactions by the same surgeon and between different surgeons. One medial wall fracture occurred in the control group only. There was no difference in the degree of graft compaction or in the subsidence of the implant post cyclical loading.

Conclusion: Impaction bone grafting can be a difficult surgical skill with a significant learning curve. We believe that this new technique of applying vibration coupled with drainage to the IBG process in the acetabulum can reduce the risk of intraoperative fracture whilst achieving good graft compaction and implant stability. This technique therefore has the potential to widen the ‘safety margins’ of IBG and reduce the learning curve allowing more widespread adoption of the technique for replacing lost bone stock.

The CMI pyrocarbon implant is a unipolar arthroplasty for trapeziometacarpal joint arthritis which is implanted in to the thumb metacarpal. Previous case series have shown these implants provide significant pain relief and good patient satisfaction. We report the first cases of pyrocarbon hemiarthroplasty from Peterborough.

Seventeen cases in fifteen patients were retrospectively reviewed. The average patient age was 59.7 years (range 47–72). 7 patients were men and 8 were women. Five were discharged with good outcome at a mean of 11.5 months (range 6–19). One failed to attend follow up.

Most patients in whom the implant survived were afforded good pain relief by the procedure and had a good functional range of thumb movement. Radiologically 8 implants were subluxed by at least 50%. One implant was revised after dislocation and loosening of the prosthesis which was associated with trauma. She made excellent clinical progress after revision of the prosthesis. One of the thirteen cases dislocated and was revised to a trapeziumectomy after 11 months.

Preliminary results suggest that this implant affords good pain relief and functional improvement in managing OA at the TMC joint. Longer term follow up will be required to correlate clinical and radiological outcomes.

Introduction: Impaction bone grafting (IBG) using fresh frozen morsellised allograft is considered by many as the method of choice for replacing lost bone stock encountered during revision hip surgery. Bone marrow contains multipotent skeletal stem cells which have the potential to differentiate down a number of different cell lineages including osteoblasts, chondrocytes and adipocytes. In IBG it is desirable for as many as possible to go on to form bone rather than fibrous tissue to form a solid osseous construct. Whilst it is possible to push cells down the osteogenic lineage in vitro, some of these methods (e.g. the addition of Dexamethasone) are not translatable to clinical practice due to undesirable side effects. In this study we test the hypothesis that by coating the allograft with type 1 Collagen prior to seeding with human bone marrow stromal cells (hBMSC), the cellular adhesion and proliferation down an osteogenic lineage can be increased, leading to improved mechanical and biological properties of the IBG composite.

Methods: A control group of plain allograft and three experimental groups where used to determine the effects that collagen and hBMSC have on IBG (both individually and in combination). The samples where impacted in standardised fashion previously validated to replicate Femoral IBG, and cultured in vitro for 2 weeks. The samples then underwent mechanical shear testing giving a family of stress strain curves for each group, from which a Mohr coulomb failure curve can be plotted. Using the Mohr Coulomb failure equation τ = σ tanΦ + c, the shear strength (τ), Internal friction angle (tanΦ) and inter particulate cohesion (c) can then be calculated. Biochemical analysis was also performed for DNA content and Osteogenic activity.

Results: Mechanical shear testing demonstrated a significant improvement (p=0.002) in the grafts ability to resist shear with the coating of Collagen and seeding with hBMSC (245 vs 299 kPa) as well as improved cohesion between the bone graft particles (46 vs 144 kPa). Regression analysis of the shear strength showed a linear increase with compressive stress (R2 > 0.98) for all groups, indicating that the grafts satisfied the Mohr Coulomb failure law. In the two groups seeded with cells, the collagen coated group also showed increased osteogenic cell activity compared to the plain allograft.

Conclusion: This study has shown a role in the improvement of the mechanical and biological properties of IBG coated with type 1 Collagen and seeded with hBMSC. Collagen coating of IBG is a facile process and translation of the technique into the theatre setting feasible. The improvement in shear strength and cohesion could lead to earlier weight bearing for the patients and allow quicker recovery. The therapeutic implications of such composites auger well for orthopaedic applications. We are currently strengthening the above findings with an in vivo study.

To assess the outcome of knee “arthrodesis” using cemented Endo-Model knee fusion nail in failed Total Knee Replacement (TKR) with significant bone loss due to infection. This is a retrospective case study of seven patients with infected TKR and multiple surgeries with significant bone loss.

All patients had antibiotic loaded cement with a temporary K-nail as a first stage procedure to eradicate infection. All seven patients had “arthrodesis” performed using cemented modular Endo-Model Knee Fusion nail (Waldemar Link, Hamburg) by the senior author. Cement was used to hold the stems in the diaphyses and not used around the coupling mechanism. The “arthrodesis” relied entirely on the coupling mechanism which has been shown to have good axial and torsional rigidity by mechanical testing. Outcome was assessed using pre and post Visual Analogue Score (VAS).

Mean age was 72.3 years(62–86). Mean follow up was 39.6 months (7–68). The VAS pain score improved from pre-operative mean score of 7.9 to a postoperative score of 1.5. One patient suffered fracture of femoral cement mantle at 50 months who underwent a technically easy exchange revision. One patient had recurrent infection with distal femoral fracture at 36 months and was revised to distal femoral replacement.

The Endo-Model knee arthrodesis nail restores limb lengths, has good early results in terms of pain relief and provides a stable knee “arthrodesis” in cases where there is significant bone loss and extensor mechanism insufficiency following an infected TKR.

Introduction: The Ionising Radiations Medical Exposure Regulations Act 2000 has established diagnostic reference levels for radiological examinations, however at present there are no national guidelines available for orthopaedic trauma surgery. There may be a role for the introduction of diagnostic reference levels at a local level therefore we studied patient area dose and screening time for orthopaedic trauma operations performed in the Regional Trauma Centre in Northern Ireland.

Methods: Retrospectively data was retrieved from written radiography records in the Royal Victoria Hospital, during the period of 1st January 2007 to 31st December 2007 for all orthopaedic trauma cases in which an image intensifier was used. The screening time, patient area dose (PAD), details of the operation, patient age, sex, month of the operation and grade of the operating surgeon (trainee or consultant), were recorded.

Results: 1709 cases using image intensifier were reviewed. 137 cases were excluded due to incomplete data. 319 hips were screened for insertion of sliding hip screw, mean screening time was 0.51min with a mean PAD of 145cGycm2. 127 femoral nails were inserted with an average screening time of 1.84min and mean PAD of 310cGycm2. 166 tibias were screened for application of Ilizarov frame or insertion of tibial nail, average screening time was 3.00min with a mean PAD of 48cGycm2. 129 spinal cases were screened with an average screening time of 0.80mins and mean PAD of 37.9cGycm2. Consultants had lower screening times and mean PADs than trainees with 0.63min versus 1.01min and 65.8cGycm2 versus 70.9cGycm2.

Conclusions: The average screening times and mean PADs compared favourably with local reference guides for image intensifier cases and with other published series. Every trauma unit should have local reference ranges for orthopaedic imaging cases and regular audit should be carried out to assess compliance with these ranges.

Background: The simultaneous occurrence of spina bifida occulta (SBO) and spondylolysis has been noted previously. The occurrence of SBO and spondylolysis are approximately 17% and 5% respectively.

Aims: The aim of this study was to determine the incidence of SBO when a symptomatic spondylolysis has been proven.

Method: Analysis of four years of lumbar spine CT scans was performed. Patients with spondylolysis or spondylolisthesis caused by a pars defect were identified. These patients’ CT images were then reviewed to establish the patients who also had SBO.

Results: In this unit 650 CT scans of lumbar spines were performed in the last five years. Of these scans 100 (15%) were found to have a pars defect. The average age was 34.6. On CT 30 (30%) patients were shown to have SBO. Of the total 23 were under 18 years old and 13 (56%) of these patients had SBO associated with the spondylolysis. In the over 18 year olds 21 (27%) patients had SBO associated with spondylolysis.

On review of the 550 other scans the average age was 51.9 years old. The incidence of SBO within this group is 10%. Only 6% of these patients were under 18. Out of these 33 patients 30.3% (10 patients) had SBO. Over 18 the incidence of SBO was only 8.5%.

Conclusions: Our results indicate that the occurrence of SBO within the group with a spondylolysis is much higher than in the group where no spondylolysis is present. There is higher incidence of SBO in the younger patients with spondylolysis. 56% of paediatric patients with symptomatic spondylolysis will have SBO. Clinicians should be aware of this fact preoperatively to decide on the technique of repair of the symptomatic lysis.

Introduction: Measurements taken from digital radiographs and corrected for the labelled scale do not correspond to actual clinical dimensions accurately.

Methods: The routine radiographs taken of 30 hip hemi-arthoplasty patients were used to make measurements in the region of the hip. 15 patients were compared in two hospitals using different digital imaging processing. The images were scaled to 100% (actual size), three blinded measurements were taken of the prosthetic femoral head and the average calculated. These results were compared to the actual size of the implanted prosthesis. Further analysis was carried out to determine true magnification.

Results: A consistent difference was observed between measured dimensions at 100% scale and known actual prosthesis dimensions. It was identified that the magnification factor ranged from 110 to 115% with at average magnification factor of 113%. No significant difference was observed between the two hospital systems.

Discussion: Many factors influence radiographic magnification, including variations in distances from x-ray source to patient and from x-ray source to x-ray plate. Angulation and degree of divergence of the x-ray beam and rotation of a limb also influence the magnification which occurs. Accurate measurements can only be taken from digital x-rays if appropriate calibration is performed.

Giant cell tumour of bone (GCTB) is an expansile osteolytic tumour of bone which contains numerous osteoclast-like giant cells. GCTB is a locally aggressive tumour which can cause extensive bone destruction that can be difficult to control surgically, up to 35% of cases recurring after simple curettage. Bisphosphonates are anti-resorptive agents that have proved effective in the treatment of a number of osteolytic conditions.

In keeping with its known effect on osteoclasts, we found that the aminobisphosphonate zoledronate abolished in vitro lacunar resorption in cultures of osteoclasts isolated from GCTB. The effect of zoledronate and other bisphosphonates on 15 cases of recurrent primary GCTB, four of which had metastasised to the lung, was assessed clinically. Most recurrent tumours did not exhibit progressive enlargement and, in some cases, both primary and metastatic GCTBs showed a degree of radiological improvement following treatment However, tumours did not diminish in size and, in some cases, no apparent treatment effect was noted.

Our findings provide in vitro evidence for the use of bisphosphonates to inhibit the progressive osteolysis associated with GCTB. In vivo, these agents produced a degree of clinical and radiological improvement in some cases. This study reports results from three European centres where bisphosphonates are being used to treat recurrent GCTB and highlights the fact that these centres are all employing different clinical indications and different regimes of bisphosphonate treatment. Bisphosphonates have significant side effects and indications for treatment and standardisation of drug type and dosage regimes (and measurement of agreed outcome measures to determine treatment efficacy) should be established before these agents are included as part of a treatment protocol to control GCTB tumour growth and osteolysis.

Introduction: Percutaneous in situ pinning of severe SUFE can lead to problems. We describe our technique and results for surgical dislocation to reduce severe SUFE.

Method: Ganz’s approach of greater trochanteric flip, safe dissection and surgical dislocation to preserve the femoral head blood supply was followed to anatomically reduce the femoral head. We have treated 16 cases in this way, but describe nine with a minimum follow up of 2 years. Their mean age was 13.6 years (9 to 16 years). All had severe SUFE with four acute on chronic and two unstable slips. Two were previously pinned and another had a partially fused growth plate. The mean follow up was 3.1 years (2.1 to 4.6 years).

Results: All patients had a good to excellent outcome. Their pre-operative deformity was 84 degrees (65 to 110) measured by AP and cross table lateral x-rays, CT or MRI scans. The average hip external rotation deformity was 70 degrees. Post operatively internal and external rotation and all other movements were similar to the contra-lateral uninvolved hip. None developed avascular necrosis (AVN) or chondrolysis

Conclusions: This technique is demanding but can give good results for severe SUFE.

Objectives: To ascertain the frequency and causes of both re-admissions and re-visits (i.e. those not requiring overnight stay) to the hospital following primary and revision TKRs.

Methods: All TKRs performed between April 2007 and March 2008 were included in the study. Mean follow-up period was 9 months (range 3–15 months). Patient data was accessed via computerized patient information systems giving access to the details of inpatient admissions, A& E attendances, laboratory results, radiology reports and clinic letters. Pattern of re-hospitalisation with regards to the cause and time period post-surgery was recorded as well.

Results: Total number of primary TKRs performed in the year was 839 and the re-admission and re-visit rates were 8.22% and 4.17% respectively. The overall re-hospitalisation rate was 12.4%. Most common causes for readmission were pain/stiffness requiring MUA (1.67%) and superficial infections (1.55%). Majority of the revisits were for continuing joint pain (1.67%) and suspected DVT.

Total number of revision TKRs was 136 with a readmission and re-visit rate of 9.7% and 1.49% respectively. The total re-hospitalisation rate was 11.19%. Deep Infections were a prominent cause of readmission (4.4%).

Discussion: Around half (49.5%) of re-hospitalisations were seen in an Orthopaedic setting, the remainder presented to A& E (19.23%), Medical Assessment Units (16.35%) or General Medical Wards (7.7%). Following a primary TKR DVT/PE rates were less than 1% (0.83%). A vast majority (48.6%) of all re-admissions however, occurred within 28 days of discharge. The tradition of seeing patients for the first time in clinic postoperatively after 6–12 weeks may not be appropriate if the majority of re-admissions occur within 28 days.

Conclusion: Idiopathic joint pain and early infections are a major cause of re-hospitalisation. Re-scheduling the first follow-up appointment within the first month after a joint replacement can decrease the overall re-hospitalisation rates and also decrease the impact of these patients on other departments.

Purpose of the study: The purpose of this study is to present our initial experience of single stage revision surgery for infected total knee arthroplasty (TKA).

Methods and results: 12 patients underwent single stage revision for infected TKA. The average patient age was 72.5 years and M: F was 2:1. 5 of the 12 patients had frank infection with presence of discharging sinuses pre-operatively. The procedure involved explantation, debridement, subtotal synovectomy, use of high pressure carbon dioxide (Carbojet) and re-implantation using revision prosthesis and antibiotic laden cement. Utmost care was taken to restore the balance and stability of the revised knee. All the patients were given appropriate intravenous and oral antibiotics in the peri-operative period. Oxford knee scores (OKS) were obtained pre-operatively and at the latest follow-up. Patient satisfaction was also assessed.

At the latest follow-up, none of the patients had recurrence of the infection nor did they need any further surgical procedure. There was no radiographic evidence of loosening of the prosthesis. The OKS had improved from a mean of 17 pre-operative to 41 at the latest follow-up. All the patients were extremely satisfied with the outcome.

Conclusion: Knee function and patient satisfaction improved significantly after single stage revision for infected TKA. None of the patients needed further surgery in the short term. Early results are very encouraging and this change in practice may save on costs and patient morbidity associated with the second stage.

Introduction: Plastic deformation of the regenerate bone is a complication noted soon after limb lengthening. However, less is known about the factors responsible for the development of plastic deformation.

Materials and Methods: Retrospective analysis of 35 X-rays of achondroplast children who had limb lengthening were reviewed. The study compared Monofocal Vs Bifocal and Long lengthenings(> 10 cms) Vs modest lengthenings(≤ 10 cms) of tibial lengthening. Other parameters included in study were Bone healing Index, total length gained and sagittal and coronal axial deformities. There were 20 females and 15 males, 21 long lengthenings and 14 modest lengthenings in the study. The joint orientation and diaphyseal angles(antero-posterior and lateral X-ray views) was used for the measurement of plastic deformation of the regenerate bone.

Results: The mean age at operation was 10 years (range; 6–16 years). There were 29 cases of monolateral fixator and 6 of Ilizarov ring fixator, Of which 26 had monofocal lengthening and 9 had bifocal lengthening (34 callotasis and 1 chondrodiastasis). The total average length gained was 10 cms (range; 23–152). The mean bone healing index and external fixation index/time were 41 days and 352 days respectively. Plastic deformation of the regenerate bone was seen in 26 cases in total. 24 out of 29 cases of monolateral fixator (82%) developed plastic deformation. 44%(4/9) of bifocal group and 84%(22/26) of monofocal group showed evidence of plastic deformation. The long lengthenings showed plastic deformation in 85% (18/21) of the cases, whereas only 57%(8/14) of the cases were positive in modest lengthening group. Most of the axial deviation was in the coronal plane in 92% (24/26) and the sagittal plane accounted to only 23%(6/26) requiring surgical correction.

Conclusions: Long lengthenings and monofocal techniques showed more plastic deformation than bifocal and short lengthenings. However, Ilizarov ring fixator with bifocal corticotomy seemed to be promising with less association with the above entity in our recent experience.

Introduction: As knee arthroplasty is becoming more commonplace in the working population its outcome and probability of return to work is of interest. Despite a wealth of anecdotal evidence about patient return to work post knee arthroplasty there is nothing published in the recent literature. The NHS Direct patient information website quotes patients return to work about 6 to 8 weeks post knee arthroplasty. In order to address this lack of informed information we conducted a retrospective survey.

Methods: 148 consecutive patients of working age, who underwent knee arthroplasty in 2007 were identified by our Electronic Patients Record. (52 male, 96 female, average age 58 years (range 37–65 years)) They were asked to complete a simple questionnaire relating to their occupational history, arthroplasty satisfaction and their current working capacity.

Results: Our survey had a response rate of 67% (99/148 responders, 64 female and 35 male), with a range of follow up from 7 to 19 months. 39% of patients were in employment at the time of their arthroplasty, with 46 % (46/99) returning to some working capacity post surgery. 32% (32/99) patients were able to return to their exact same employment. 88% (28/32) of these patients had worked up to the date of their arthroplasty. There was no correlation between operative indication or type of prosthesis implanted and patients who returned to employment and those who did not.

Conclusion: Despite high expectation in lay literature of ability to work post knee arthroplasty, only 46% of our patients returned to any form of employment. For patients who returned to work, the duration of sick leave prior to their surgery was a strong predictor of whether they returned to any form of employment. Caution must be exercised when informing patients of likelihood of return to work post knee arthroplasty.

Introduction: Impaction bone grafting (IBG) for revision hip surgery can be a difficult surgical skill with a fine line between construct failure from insufficient compaction and intraoperative fracture from high impaction forces. Following on from our experience in the femur, in this study we used an acetabular model to test the hypothesis that the use of vibration for IBG could reduce the peak stresses thus reducing the intraoperative fracture risk and also improve the reliability and reproducibility of the impaction technique.

Methods: Revision hemi pelvis models were made (Pra-prosky Type 2a). A standard impaction technique was used for the control group, and the impactor tamps were coupled with a pneumatic hammer for the vibration group. The cavity was filled in 6 set steps with strain gauge readings taken throughout. The pelvis construct was then mechanically loaded. Graft compaction and micro motion post mechanical testing was assessed with micro CT.

Results: Vibration impaction led to a significant reduction (p=0.03) in the peak stresses during the impaction process. There was also significantly less variability in peak stresses for the vibration group compared to standard, both in sequential impactions by the same surgeon and between different surgeons. One medial wall fracture occurred in the control group only, similar to fractures encountered in the clinical situation. There was no significant difference in the degree of graft compaction or in the subsidence of the cup.

Discussion: We believe that this new technique of applying vibration to the IBG process can reduce the risk of intraoperative fracture whilst achieving good graft compaction and implant stability. This technique therefore has the potential to widen the ‘safety margins’ of IBG and reduce the learning curve allowing more widespread adoption of the technique for replacing lost bone stock.

Aim: To review our experience with epiphysiodesis using three different methods to correct LLD and to establish the efficacy of these procedures.

Method: A retrospective review of 42 patients from 1999 to 2008 with at least one year follow-up recorded type and location of the epiphysiodesis, average operating time and hospital stay, complications, method of prediction, timing and the final LLD. CT scanograms and mechanical axis view with grids were used to assess LLD.

Results: Epiphysiodesis was as per Canale for 26, by Metaizeau screw in 14 and by staples in 2. Average operation time was 42 minutes for Canale type, 45 minutes for the screws and 56 minutes for the staple cases. The pre operative LLD of 3.7 cms In the Canale group, improved to 1.2 cms over an average follow-up of 2.1 yrs. There were 4 minor and 2 major complications with a 92% success rate. For the screw group, the mean change was 1.8 cms over 2.2 yrs with 2 minor and 2 major complications giving a success rate of 85%. With staples the success rate was 100% and the mean change was 1.8 cms at an average of 2.3 yrs. In 14 cases where bone age reports were available, the multiplier method seemed better at predicting estimated LLD at skeletal maturity and timing of epiphysiodesis than the Moseley chart.

Conclusions: Percutaneous epiphysiodesis by any method is reliable, minimally invasive and with acceptable complication rate when compared to a corrective osteotomy or open Phemister-type epiphysiodesis. Our experience suggests that the Canale method has the least complications and best success rate. Paleys multiplier method was better at predicting LLD and timing of epiphysiodesis than the Moseley Chart.

Aim: To review our experience with hemi-epiphysiodesis using different methods for the correction of angular deformity about the knee.

Method: This was a retrospective review of 73 patients (101 knees) who underwent hemi-epiphysiodesis from 1999 to 2008. Assessment looked at the type and degree of deformity, implants used, average operating time and hospital stay, complications, degree of correction and the average time to correction.

Results: There were 50 boys and 23 girls with bilateral deformity in 28 cases. There were 88 valgus and 13 varus knees. Average follow-up was 17 months. Staples were used in 28 cases, “8” Plates in 24, Screws in 16 and Drilling in 5 cases. The distal femoral physis was involved in 46 knees, the proximal tibial physis in 21 and both physes in 34 knees (total 135 physes). Average operation time and hospital stay were similar for all methods. There were 6 minor and 3 major complications with staples with an average correction time of 14 months, 3 minor complications with an average correction time of 11 months with “8” plates, 3 minor and 1 major complication with an average correction time of 14 months with screws and 1 minor complication with drilling with an average correction time of 13 months. The outcome was considered as resolved in 47 and pending in 26 cases, with all showing progressive correction of deformity.

Conclusions: Hemi-epiphysiodesis by any method is an effective way to correct angular deformities about the knee in skeletally immature individuals within a reasonable time limit and with minimal morbidity when compared to a corrective osteotomy. Our experience suggests that “8” plates achieve faster correction with the least complications when compared to other methods. Valgus knee deformities corrected faster than varus ones.

Background: Satisfaction following anterior and/or posterior spinal fusion varies greatly between individuals. The aim of this study was to assess patient satisfaction with the post-operative scars following surgical correction of scoliosis.

Methods: Prospective study; 31 patients (range 10–37 years), minimum of 2 months post-operation, interviewed in clinic or over the telephone using a questionnaire.

Results: Overall, 18 (58%) patients were disappointed with their scar; it was not what they expected, Patients with anterior scars or both anterior and posterior scars were the most disappointed groups.

39% of patients felt they were inadequately informed or not informed of the nature of scar. However, over 50% of those who had a specialist spinal nurse (SSN) consultation reported the scar to be as they expected. Scar length was the main source of disappointment. 55% reported their scars as being raised (keloid), particularly at the ends. Scar colour and shape was an issue for 23%, whilst 39% experienced prolonged healing. 19 patients had a pre-op consultation with the SSN, 11 did not get this opportunity, 1 declined.

Conclusion: Clearly there’s a need for improved education and understanding with regard to the nature of the scoliosis surgical scar(s). Input from a SSN is important and surgeons must clarify exactly what they mean when discussing operations with patients. This could be done with the aid of pictograms or leaflets detailing issues discussed in consultations along with the opportunity to meet patients who have already had surgery. These measures may lead to increased patient satisfaction with surgery.

Ethics approval: Audit

Interest Statement: None

Aim: To review our practice of performing two-stage revision for infected total knee arthroplasty by using articulating interval prosthesis and short course parenteral antibiotic therapy

Patients and Methods: We included 70 patients treated by a single surgeon using a uniform protocol since 2001. All patients were planned to have two- stage revision for infected total knee arthroplasty with an articulating interval prosthesis made up of cruciate retaining femur and all poly tibia at stage one. All patients were given short course parenteral antibiotic therapy (5 days IV) followed by and 6 weeks dual oral therapy.

Results: The average age was 68 yrs at the time of first stage. Five patients required repeat of 1st stage procedure because of persistent infection. Twenty six (40%) patients opted not to have a 2nd stage procedure because of eradication of infection after 1st stage and good functional result with interval prosthesis. We had recurrence of infection in 6 patients after two-stage procedure at a mean follow up of 42 months. Four patients out of these six had multiple surgeries for infection before our two-stage protocol

Conclusion: Articulating interval prosthesis gives excellent function and also makes subsequent revision easier with well preserved soft tissue balance. It also takes pressure off on the time constraint for the 2nd stage and good number of them may not require a 2nd stage at all. Our results of recurrence are comparable with published literature evidence and we don’t think that prolonged parenteral antibiotics therapy is required provided adequate surgical debridement has been performed.

The purpose of this study was to establish the a)feasibility, b) reproducibility of spinal Quantec scans (a non-intrusive surface topography system) and c) the validity of the Quantec Q-angle against Cobb angles from spinal radiographs, in non-ambulant children with cerebral palsy (CP).

Eighteen non-ambulant children (aged 5–11 years) with CP had successful clinical, radiological and Quantec assessment of their spine while seated in a supportive seating system.

Scoliosis incidence was 72%, Cobb angles ranged from 1–73° (mean 18.2°). Quantec scanning was feasible with appropriate postural support. Mean interobserver differences were 0.5 ± 5.8° (median 1.3°, 5 / 95th percentiles lying at −7.3 / 8.5° respectively). Mean differences between Cobb and Q-angle were 0.02 ± 6.2° (median 1.0°, with 5 / 95th percentiles lying at −8.2 / 7.7° respectively).

Surface topography may be used to safely monitor the spine for non-ambulant CP children. Results show similar or improved trends to previous comparisons with idiopathic scoliosis. Ovadia (2007) showed an interobserver mean difference of 6.3 ± 4.9° using an Ortelius800TM system. Thometz (2000) showed mean differences between Cobb and Q-angle ranging from 1.1–12.6 ± 4.9–10.2°. Further research is needed for the user group described in this study with larger spinal curves.

Ethics approval: Ethics approval granted by Leeds (West) Research Ethics Committee

COREC number: 08/H1307/22

Interest Statement: None

The aim of this study was to evaluate the impact of a preoperative education programme on length of hospital stay for primary and revision knee arthroplasty patients.

The programme was introduced at our hospital in October 2006 to encourage patients to play an active role in their postoperative recovery process. It was delivered by a multi-disciplinary team consisting of an arthroplasty nurse, ward physiotherapist, occupational therapist and orthopaedic consultant. Patients were educated about their care pathway, knee surgery, pain management, the expected discharge goal, post operative inpatient and outpatient rehabilitation. Data was prospectively reviewed for 472 patients who underwent (primary or revision) knee arthroplasty for the period between January 2006 and November 2007. There were 150 patients in the Conventional group and 322 patients in the Educational group. The mean length of stay reduced significantly from 7 days in the Conventional group to 5 days in the Education group (P< 0.01). In addition 20 percent more patients were discharged early (within 1 to 4 days) in Education group compared to the Conventional group (P< 0.01). There was no statistically significant difference in the percentage of inpatient complications and readmissions between the two groups.

Our study demonstrates that preoperative education is a safe and effective method of reducing length of stay for knee arthroplasty patients. Significantly more patients achieved discharge within four postoperative days.

Introduction: Leg length discrepancy (LLD) following total hip replacement (THR) is not uncommon. Some patients are symptomatic, with problems such as gait imbalance or back pain. LLD is a potential cause of litigation following THR.

We have observed that some patients perceive their LLD to be much greater than the true LLD. A large LLD is sometimes reported by therapists, despite only a small true LLD.

We have found that abduction tightness is a potent cause of apparent LLD, and report our investigations into this phenomenon.

Method: We have identified a series of patients with abductor tightness and a significant apparent LLD. The LLD becomes apparent when the operated leg is adducted to the midline (or when the patient stands with their ankles together). This causes the contralateral pelvis to elevate and the un-operated leg to “shorten”.

Clinical photographs and videos have been produced to demonstrate this phenomenon.

A 2-dimensional model has been made to demonstrate how the degree of abduction, offset and over-lengthening affect this phenomenon.

A computer model has been used to quantify these effects.

Results: An abduction contracture after THR will cause the un-operated leg to be apparently and functionally short, even in the absence of a true discrepancy.

Even with only minor abductor tightness, increasing the true length will disproportionately increase the apparent LLD.

Conclusion: An abduction contracture is a potent cause of apparent LLD. Even a small degree of true over lengthening will be greatly magnified by this phenomenon. We recommend careful clinical assessment for abductor tightness when examining patients complaining of a LLD after THR.

Introduction: Despite the satisfactory short-term implant survivorship of MoM hip resurfacing arthroplasty, symptomatic abnormal periprosthetic soft-tissue masses relating to the hip joint, ‘pseudotumours’, are being increasingly reported. These were found be locally destructive, requiring revision surgery in 75% of patients. Asymptomatic pseudotumours have not been previously investigated.

Methods: The aims were: (1) to investigate the prevalence of asymptomatic pseudotumours; and (2) to investigate their potential association with the level of metal ions. A total of 160 hips in 123 patients with a mean age 56 years (range 33–73) were evaluated at a mean follow-up of 61 months (range 13–88). Radiographs and OHS were assessed. Patients with a cystic or solid mass detected on the ultrasound/MRI had an aspiration or biopsy performed. Cobalt and chromium levels were analysed using Inductively-Coupled Plasma Spectrometer.

Results: Pseudotumours were found in 6 patients (5F: 1M). In 80% of bilateral cases, it was found in both sides. Histological examination showed extensive necrosis and diffuse lymphocyte infiltration. The presence of pseudotumour was associated with higher serum cobalt (9.2 μg/L vs. 1.9μg/L, p< 0.001) and chromium levels (12.0μg/L vs. 2.1μg/L, p< 0.001); higher hip aspirate cobalt (1182 μg/L vs. 86.2μg/L, p=0.003) and chromium levels (883μg/L vs. 114.8μg/L, p=0.006); and with inferior OHS (23 vs. 14 p=0.08).

Discussion: The prevalence of asymptomatic pseudotumour (5%) was higher than previously reported for the symptomatic pseudotumours (1%). There was a sixfold elevation of serum and a twelve-fold elevation of hip aspirate levels of cobalt and chromium in patients with pseudotumours. This suggests that pseudotumours may be a biological consequence of the large amount of metal debris generated in vivo. The association between pseudotumour and elevated metal ion levels might theoretically be explained by either systemic hypersensitivity responses to metal ions or local cytotoxic effects due to a high level of metal ions.

Introduction: Obligatory external rotation during flexion is well recognised as a cardinal feature of Slipped Upper Femoral Epiphyses (SUFE). We have evaluated the significance of acetabular version in contributing to the external rotational deformity that is seen in otherwise normal hips. We present a small case series focussing on the characteristics of this pathology, highlighting its significance and outlining a treatment strategy.

Method: Five patients (eight hips) presented with disabling hip pain during non-sporting activities. All their hip radiographs had been reported as normal. The rotational profile of both acetabulum and femur in these patients was evaluated by MRI and CT scans.

Results: Clinical examination revealed otherwise normal hips but for an external rotation deformity which got worse on hip flexion. The average external rotation deformity with the hip in extension was 60 degrees, which worsened to 90 degrees during hip flexion. Three of these hips had been previously treated with in situ pinning for SUFE. Other hips were in patients who were either skeletally mature or close to skeletal maturity. We found that all were “profunda hips” with severe acetabular retroversion. The abnormality in acetabular version was best defined on axial imaging.

Conclusions: The femoral head is a spherical conchoid. The concept of version of the hip (both femoral and acetabular) as described by McKibbin, Tonnis and Ganz is reviewed. Femoral retroversion is common in patients with SUFE, but the addition of acetabular retroversion makes these hips disproportionately symptomatic. This deformity causes a combination of pincer and cam impingement, which is responsible for the marked disability. SUFE alone causes cam impingement, whilst a corresponding degree of slip without retroversion and profunda of the acetabulum is not that disabling.

Introduction: Inaccuracies in kinematic data recording due to skin movement artefact are inherent with motion analysis. Image registration techniques have been used extensively to measure joint kinematics more accurately. The aim of this study was to assess the feasibility of using MRI for creating 3D models and to quantify errors in data collection methods by comparing kinematics computed from motion analysis and image registration.

Methodology : 5 healthy and 5 TKR knees were examined for a step up/down task using dynamic fluoroscopy and motion capture. MRI scans of the knee, femur and tibia were performed on the healthy subjects and were subsequently segmented using ScanIP(Simpleware) to produce 3D bone models. Registration of the models produced from fine and coarse scan data was used to produce bony axes for the femoral and tibial models. Tibial and femoral component CAD models were obtained for the TKR patients. The 3D knee solid models and the TKR CAD models were then registered to a series of frames from the 2D fluoroscopic image data (Figure 1) obtained for the 10 subjects, using KneeTrack(S. Banks, Florida) to produce kinematic waveforms. The same subjects were also recorded whilst performing the same action, using a Qualisys (Sweden) motion capture system with a pointer and marker cluster-based technique developed to quantify the knee kinematics.

Results: The motion analysis method measured significantly larger frontal and transverse knee rotations and significantly larger translations than the image registration method.

Conclusion: The study demonstrated that MRI, rather than CT scan, can be used as a non-invasive tool for developing segmented 3D bone models, thus avoiding highly invasive CT scanning on healthy volunteers. It describes an application of combining fine and coarse scan models to establish anatomical or mechanical axes within the bones for use with kinematic modeling software. It also demonstrates a method to investigate errors associated with measuring knee kinematics.

The purpose was to develop an objective measurement system to assist in the prescription of supportive seating for non-ambulant cerebral palsy children with scoliosis.

Currently the prescription of patient’s bespoke seating setup relies on clinical skills and knowledge of trained seating staff (physiotherapists and engineers). Therefore to develop an objective measurement system to supplement this clinical approach, a user centred design approach was used.

Standard design processes presented in Pahl’s ‘Engineering Design’ (2007) were adopted, allowing in depth user involvement. Stakeholders (clinical, seating, and technical staff) were interviewed to develop requirements lists for each group. Following each development stage; task clarification; concepts; embodiment; detailed design; manufacture; and commissioning, these requirements were reviewed with stakeholders.

Requirements lists were collated to form the device specification, involving all stakeholders allowed the discussion of contradicting requirements. The final design incorporated critical aspects of seating while measuring important outcomes such as force distribution and spinal deformities.

A user centred design approach allowed for informative decision making from stakeholders, highlighting the fundamental requirements and facilitated effective solutions to meet these requirements.

The manufactured device complies with the collaborated specification, utilising stakeholder defined spinal and seating parameters. This was commissioned for use in a pilot study involving twenty non-ambulant cerebral palsy children aged 5–11 years, with high risk of scoliosis.

Ethics approval: Ethics approval granted by Leeds (West) Research Ethics Committee

COREC number: 08/H1307/22

Interest Statement: None

This study aims to evaluate the accuracy of sheer off self limiting screw drivers and to assess repeatability with age.

It has been reported that overzealous tightening of halo pins is associated with co-morbidity. Our unit has recently received a tertiary referral where the patient over tightened a pin leading to intracranial haematoma, hence our interest in this subject. The torque produced by six new and nine old screw drivers was tested using an Avery Torque Gauge and a Picotech data recorder. These devices are designed to produce a torque of 0.68 Nm, any greater than this is potentially hazardous. Accepted error for each device was +/− 10%. The average torque produced by the new screw drivers was 0.56 Nm with a range of 0.35–0.64 Nm (SD 0.120). The older screw drivers produced an average torque of 0.67 Nm ranging from 0.52–0.85 Nm (SD 0.123).

In conclusion, sheer off self limiting screw drivers are not accurate devices. The older devices are more likely to produce a torque exceeding a safe range and therefore we would recommend the use of new devices only.

Ethics approval: none audit.

Interest statement: none local grant.

Purpose of the study: We report an unusual complication of patella tendon rupture that occurred secondary to the use of static cement spacer blocks in a series of three patients undergoing staged revision total knee arthroplasty (TKA) for infection.

Methods and results: 3 male patients developed patella tendon injury secondary to anterior subluxation of static cement spacer blocks used at the first of a two-stage revision procedure for infected TKA. Average patient age was 70 years. The interval between the 1st and the 2nd stages varied between 3.5 to 24 months. At the second stage, it was observed that the patella tendon was completely severed and irreparable in one case, whereas it was partially injured and repairable in the other two cases. In the case with irreparable tendon injury, stable joint reconstruction could not be achieved at the second stage and ultimately resulted in knee arthrodesis. In the other two cases, 2nd stage revision was performed using hinged revision knee components and the tendon injury was repaired and protected with a circlage wire. None of the patients were satisfied with their outcome at the final review.

Conclusion: This is the first report in the literature reporting the complication of patella tendon rupture secondary to the use of static cement spacer blocks in staged revision knee arthroplasty. The injury can either be repairable or irreparable. The functional outcome and satisfaction is not good after the salvage procedures. Therefore, we recommend that these spacer blocks should not be used in revision knee arthroplasty.

Background: It remains unclear and controversial whether preoperative magnetic resonance imaging (MRI) in patients with adolescent idiopathic scoliosis (AIS) should be mandatory.

Aim: (1) To review our own practice, (2) conduct a national survey of United Kingdom Consultants, and (3) to perform a literature review.

Methods: Our own practice was established by identifying patients with AIS and examining whether an MRI scan was performed preoperatively. A survey of Consultants practice in the UK (British Scoliosis Members) was conducted by either an e-mail or telephone conversation. Finally, a literature survey was performed to establish current views.

Results: 118 patients with AIS were identified between 2003 and 2007. 78% of these patients underwent pre-operative MRI scans. Neural axis abnormalities were found in 8% of these patients. They included syrinx’s, chiari malformations, tonsillar herniation, cord tethering, central canal dilatation and undiagnosed spina bifida. Only 1 patient required intervention by the neurosurgeons. 92% of respondents to the national survey routinely performed preoperative MRI scans. The literature was not conclusive with regards to mandatory preoperative imaging.

Conclusion: Despite the literature showing little evidence, our survey shows a widespread consensus in clinical practice across the UK that routine preoperative MRI should be performed from a risk management viewpoint. It is mandatory in our unit to perform pre-operative MRI scans on all patients with AIS and would recommend that this becomes standard practice in all other units.

Ethics Approval: None/Audit

Interest Statement: None

Introduction: One of the main factors in the success of impaction bone grafting (IBG) in revision hip surgery is its ability to resist shear and to form a stable construct. Bone marrow contains multipotent skeletal stem cells and we propose that in combination with allograft will produce a living composite with biological and mechanical potential. In this study we looked at whether coating of the allograft with type 1 collagen followed by seeding with human bone marrow stromal cells (hBMSC) would enhance the grafts mechanical and biological properties.

Methods: A control group of plain allograft and three experimental groups where used to determine the effects that collagen and hBMSC have on IBG. The samples where impacted in standardised fashion previously validated to replicate femoral IBG, and cultured in vitro for 2 weeks. The samples then underwent mechanical shear testing and biochemical analysis for DNA content and Osteogenic activity.

Results: In isolation, both Collagen coating and seeding with hBMSC significantly enhanced the mechanical properties of the construct compared to the ‘gold standard’ of plain allograft. This was further enhanced (p=0.002) when the two processes are combined both with shear strength (245 vs. 299 kPa) and cohesion between the graft particles (46 vs. 144 kPa). The collagen coated group also showed increased osteogenic cell proliferation.

Discussion: This study has shown a role in the improvement of the mechanical properties of IBG coated with collagen and seeded with hBMSC. Collagen coating of IBG is a simple process and translation of the technique into the theatre setting feasible. The improvement in shear strength and cohesion could lead to earlier weight bearing for the patients and allow quicker recovery. The therapeutic implications of such composites auger well for orthopaedic applications. We are currently strengthening the above findings with an in vivo study.

Aim: To assess the outcome of knee arthrodesis using cemented Endo-Model knee fusion nail in failed total knee arthroplasty with significant bone loss due to infection.

Methods: A Retrospective case study of seven patients with infected TKR and multiple surgeries and significant bone loss (Type III AORI classification). All patients had antibiotic loaded cement with a temporary K-nail as a first stage procedure to eradicate infection. All seven patients had arthrodesis performed using cemented modular Endo-Model Knee Fusion nail (Waldemar Link, Hamburg) by senior author (RSJ). The arthrodesis relied on the strong coupling mechanism of the nail and not on bony union, providing pain relief while mainting leg length. Outcomes assessed using pre–and post Visual Analogue Score (VAS) and Oxford knee scores.

Results: Mean age 76.8 years (62–85). Mean follow up 23.7 months (3–42). The mean VAS pain score improved from 7.6 (6.5–8.5) pre-operatively to 1.1 (0–3.2) post-operatively. The mean post-operative Oxford score was 30.3 (27–36). One patient required revision for asceptic loosening. All but one of the patients thought that arthrodesis was preferable to amputation post-operatively.

Conclusion: The Endo-Model knee fusion nail has good early results in terms of pain relief and knee arthrodesis where there is significant bone loss and extensor mechanism insufficiency following an infected total knee replacement.

Purpose: Waterproof casts have been shown to be a safe and effective means of immobilization in children with minimally displaced fractures. The purpose of this study was to determine if waterproof Gore-Tex-lined casts are as effective as traditional cotton-lined casts in the immediate postoperative period after closed reduction of displaced distal radius fractures in children.

Method: We performed a retrospective review of distal radius fractures that underwent closed reduction and application of a long-arm cast between June 2004 and December 2006. A total of 124 cases were included (55 Gore-Tex; 69 traditional cotton-lined). The primary outcome measure was redisplacement in the cast. The cast index was also used to assess the quality of cast molding. Data was analyzed using repeated measures ANOVA. Power analyses were also conducted.

Results: There were no significant differences between the two groups with regards to translation of the radius or angulation of the radius on anterior-posterior (AP) and lateral radiographs at the time of injury, postreduction, or cast removal. Redisplacement as measured by the change in translation of the radius and angulation of the radius on AP and lateral radiographs from the time of reduction to cast removal was also not significantly different between the two groups. The mean cast index for the Gore-Tex and traditional cotton-lined groups was 0.882 and 0.873 respectively, which was not a significant difference.

Conclusion: A waterproof Gore-Tex-lined cast will maintain fracture reduction as well as a cotton-lined cast for closed reductions of distal radius fractures in children in the immediate postreduction period. Waterproof casts also provide extensive benefits to the patient with regards to bathing, hygiene, and participation in aquatic activities

Introduction: The Ionising Radiations Medical Exposure Regulations Act 2000 has established diagnostic reference levels for radiological examinations, however at present there are no national guidelines available for orthopaedic trauma surgery. There may be a role for the introduction of diagnostic reference levels at a local level therefore we studied patient area dose and screening time for orthopaedic trauma operations performed in the Regional Trauma Centre in Northern Ireland.

Methods: Retrospectively data was retrieved from written radiography records in the Royal Victoria Hospital, during the period of 1st January 2007 to 31st December 2007 for all orthopaedic trauma cases in which an image intensifier was used. The screening time, patient area dose (PAD), details of the operation, patient age, sex, month of the operation and grade of the operating surgeon (trainee or consultant), were recorded.

Results: 1709 cases using image intensifier were reviewed. 137 cases were excluded due to incomplete data. 319 hips were screened for insertion of sliding hip screw, mean screening time was 0.51min with a mean PAD of 145cGycm2. 127 femoral nails were inserted with an average screening time of 1.84min and mean PAD of 310 cGycm2. 166 tibias were screened for application of Ilizarov frame or insertion of tibial nail, average screening time was 3.00min with a mean PAD of 48cGycm2. 129 spinal cases were screened with an average screening time of 0.80mins and mean PAD of 37.9cGycm2. Consultants had lower screening times and mean PADs than trainees with 0.63min versus 1.01min and 65.8cGycm2 versus 70.9cGycm2.

Conclusions: The average screening times and mean PADs compared favourably with local reference guides for image intensifier cases and with other published series. Every trauma unit should have local reference ranges for orthopaedic imaging cases and regular audit should be carried out to assess compliance with these ranges.

In January 2000 we introduced identical guidelines for the more rapid rehabilitation of Achilles tendon ruptures, whether treated operatively or non-operatively. A relaxed equinus cast was used to four weeks, then a CAM walker to eight weeks with supervised mobilisation. The aims of this study were to compare the outcomes of the operative and non-operative groups treated with the same rehabilitation program and audit the effectiveness of these guidelines.

The audit was retrospective from January 2000 till January 2008. The patients were identified from the Emergency Department admissions database, the hospital clinical coding system, the department’s surgical audit data and the hospital physiotherapy appointment system. The audit system was used to identify patients that had complications of their operative treatment, re-ruptures or readmissions. This study focused on the end points of re-rupture, readmission, complications including wound complications and infection.

Five hundred and eighty seven presentations were recorded as Achilles tendon injuries. One hundred and eighty patients were treated operatively and 407 patients were treated conservatively. Seventy five patients (42%) treated operatively and 126 patients (30%) of the non-operative group were rehabilitated in our hospital physiotherapy department. The remaining 386 patients (65.7% of all patients) received physiotherapy elsewhere or did not attend for further treatment. In the operative group there were two re-ruptures (1.1%) both treated in our hospital physiotherapy department. There were 2 wound complications (1.1%), one requiring re-operation. In the non operative group there were 15 re-ruptures (3.7%). Of these three had attended the hospital physiotherapy department (rerupture rate of 2.4%) In the non-operative group treated elsewhere there were 12 re-ruptures from 281 patients (4.2%).

Comparable results were found between operative and non-operative treatment when combined with close physiotherapy guidance. Non-operatively treated patients treated in the community may have higher re-rupture rates. The results are comparable to those in the literature suggesting that the guidelines are effective.

Purpose: To evaluate the functional outcome of operatively treated Lisfranc injuries.

Method: Over a 7-year interval from 1998 to 2005, 184 skeletally mature patients were identified retrospectively with operatively treated Lisfranc injuries. 85 patients had prospectively measured SMFA functional outcomes and satisfaction surveys. The gender was 37 males and 48 females. Mean age was 39 years (range 17–93).

Results: The mechanism was fall (31), MVA (24), crush (15), equestrian (5), or twisting (10). Patients were operatively treated with open reduction internal fixation (ORIF, 53) or primary arthrodesis (PA, 32). The SMFA reliability for this patient sample was 0.892. The function and bother outcomes were 19.4 and 15.8, respectively. The function (21.5 vs. 16.0, p=.11) and bother (17.5 vs. 13.0, p=.25) outcomes were not significantly different for ORIF vs. PA, respectively. In the ORIF group, HW removal (40 of 53) performed better than HW retention (13 of 53) with outcome bother but not function measures of (14.7 vs. 26.1, p< 0.05).

Conclusion: If performed well, either ORIF or PA technique function well. Patients are more satisfied with the results and appearance of PA over ORIF. HW removal compared to HW retention positively affect bother not function measures. Secondary surgeries negatively affect both bother and function measures. Patients with pain, associated foot or polytrauma injuries function worse.

Purpose: Simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction has been proposed as a treatment for patients with combined medial compartment knee osteoarthritis (OA) and ACL deficiency. Although goals of surgery are to correct malalignment, decrease knee joint load and enable continued participation in sports, few prospective studies evaluating these outcomes exist. Therefore, the objective of this study was to evaluate two-year changes in frontal plane alignment, dynamic knee joint load and self-reported function during sport after simultaneous HTO and ACL reconstruction.

Method: Thirty patients with varus alignment, medial compartment knee OA and ACL deficiency have undergone medial opening wedge HTO and hamstring tendon ACL reconstruction during a single operation. Full-length, standing AP radiographs (mechanical axis angle), dynamic knee joint loads (the peak external adduction moment about the knee during self-paced walking) and the Knee Injury and Osteoarthritis Outcome Scale (KOOS) were completed before and 24 months after surgery.

Results: Based on the 14 patients currently at 24.9 ± 1.67 months postop (12 males; age = 38.5 ± 7.5 yrs.; BMI = 29.5 ± 5.6, median Kellgren and Lawrence grade = 2), mechanical axis angle decreased significantly (p< 0.005) from −6.2 ± 3.63° to 0.29±1.94°. Despite a small (0.06 ± 0.10m/s), but significant (p< 0.05), increase in self-paced walking speed after surgery, the peak knee adduction moment decreased significantly (p < 0.001) from 2.96 ± 0.61 %BW*ht to 1.58 ± 0.48 %BW*ht [mean decrease = 1.38 %BW*ht (95% CI: 0.87 – 1.89)]. Each domain of the KOOS also improved significantly (p< 0.05), with the mean sports and recreation domain increasing (p=0.001) from 26.92 ± 24.29 to 66.54 ± 28.09 [mean increase = 39.62 (95% CI: 20.09 – 51.14)]. Data from 30 patients will be available at time of presentation.

Conclusion: Two-year outcomes after simultaneous medial opening wedge HTO and ACL reconstruction suggest this treatment results in substantial improvements in alignment, knee joint load and self-reported functioning during sport.

Current opinion is divided as to whether carpal tunnel syndrome requiring operative decompression can be caused by an occupation.

The aims of this study were to define the lamb freezing worker population who acquire carpal tunnel syndrome and to confirm or refute lamb boning as an occupational cause for carpal tunnel syndrome.

Roles, gender age and exposure periods of all workers who had carpal tunnel decompressions over the past six seasons at the largest lamb Freezing Works in the world were examined. Kaplan-Meier survival analysis for boners, slaughter men and non-knife labourers was performed and tested for significance. Chi-square analysis and ANOVA were performed for gender and age. Age and gender-adjusted Cox regression analysis was performed to establish relative risks/hazard ratios for each of the three groups developing carpal tunnel syndrome. Incidences for boners and non-knife hands were calculated. Comparison of this population and a standard carpal tunnel population was performed.

Two hundred and eighty five carpal tunnel decompressions were performed in workers who failed conservative management at the largest lamb freezing works in the world by a single surgeon after neurophyiological-test confirmation of the diagnosis. Of those having surgery 79% were men: 21% female and this was significant with Chi square testing (p< 0.01). At decompression boners were significantly younger than non-knife hands (p< 0.01). Adjusting for age and gender boners were 120% more likely to need decompression than non-knife labourers (p< 0.01). The median survival for a lamb boner’s carpal tunnel at five years was 44%. The incidence of carpal tunnel syndrome in lamb boners was 10% (person-seasons). This population is entirely different to the published idiopathic population requiring carpal tunnel decompression which is predominantly female with meanage of 55.

To our knowledge this is the first study to provide sound evidence that carpal tunnel syndrome can be caused by an occupation. We have quantified this and welcome ideas for further work in this fascinating a uniquely New Zealand population.

Calcium and vitamin D are both of key importance for bone health, and their effects on bone appear to begin even in utero and continue throughout life. The dietary requirements for both calcium and vitamin D are different at different stages of the lifespan. Importantly, in Australia the bulk of vitamin D comes from manufacture of vitamin D in the skin from ultraviolet light exposure i.e. from sun exposure, as the amount of vitamin D in foods is low. Vitamin D deficiency is common at all stages of life and some groups are at particularly high risk. Adequate calcium intake and maintaining adequate vitamin D levels are important in childhood for maximising peak bone mass, but the effect of calcium supplementation on bone mineral density is small. The role of vitamin D supplementation in childhood outside of treating rickets is unclear, though there is potential for a clinically significant effect. Calcium and vitamin D supplements have been investigated for the primary prevention of osteoporotic fracture in the elderly. Calcium and vitamin D is effective at reducing non-vertebral and vertebral fractures in the institutionalised elderly but community-based studies show conflicting results. There is no evidence that calcium, vitamin D or the combination of calcium and vitamin D alone prevent fractures in those who have already sustained a low trauma fracture (secondary prevention) but calcium and vitamin D are both important adjunctive treatments in established osteoporosis i.e. in combination with other pharmacotherapies.

Purpose: Pediatric femoral fracture treatment is varied. Each treatment has advantages and disadvantages. The goal of treatment is to avoid complications, reduce costs, and return function. Percutaneous bridge plating has many advantages and little disadvantages. The purpose of this study was to examine the results of percutaneous bridge plating for pediatric femoral diaphyseal fractures.

Method: Over a 4-year time span (2002–2005), all pediatric femoral fractures were diagnosed. A retrospective chart review was completed and only percutaneous bridge plating treatment was analyzed.

Results: 78 fractures were noted in 73 patients. Average age was 9 (range 3–16). Gender was 56 males and 22 females. Most common mechanisms were falls 15 (19%), MVA 12 (15%), and pedestrians 9 (12%). Four fractures (5%) were open. Forty-three fractures (61%) were associated with polytrauma. Time to operation averaged 1 day (0–11 days, 89% 0–1 day). Most plates were 3.5 combi locked plates with a lesser but equal number of 3.5 DCP and 4.5 DCP. Length of stay averaged 5 days (range 0–45 days, 18% 0–1 day, 58% 2–4 days). The majority of patients (58%) began weight bearing at 2–6 weeks. Callus formation began at 2–6 wks (84%). Fracture healing occurred by 6 weeks in 91%. Limp was resolved by 3 months in 54%. Pain was resolved by 3 months in 90%. Patients were back to active daily living without restrictions by 3 months in 96% of the fractures. Complications were noted with 4 superficial wounds, 4 problematic scars, 3 leg overgrowth < 12 mm, and 3 distal prominent plates. No nonunions or refractures were noted. Hardware (HW) was removed on average by 6 months (range 3 mo to never). Outpatient percutaneous HW removal was performed in 100% of the cases.

Conclusion: Percutaneous bridge plating for pediatric femoral fractures is predictable and effective with minimal complications. Asymptomatic femoral overgrowth was minimal.

Purpose: Many lateral malleolar fractures in patients with osteoporotic bone are rotationally unstable, requiring fixation stable in torsion with good fatigue properties, but without bulk due to the soft tissue constraints. The purpose of this study was to evaluate the torsional performance of a thin (1.5mm) plate with locked and non-locked constructs in a simulated osteoporotic lateral malleolus fracture.

Method: A transverse fracture gap to mimic comminution was created in (15 lb/ft3) density foam. 3 bicortical unlocked screws were used proximal to the fracture in a 5 hole thin (1.5mm) plate for both constructs. Distally, two screws that did not breach the far cortex (12mm) were placed as locked in one group and unlocked in the other. The constructs were loaded in torsion at 1 Hz at 7.5/0.75 in-lbf (0.85/0.08 N-m) of torque. A torsional fatigue failure was defined as either a fracture of the plate, screw pull-out, or construct rotation 10 degrees beyond the maximum initial rotational displacement. Testing was conducted until construct failure or run-out of 300,000 cycles.

Results: The thin plate constructs with locked distal screws showed significantly improved fatigue properties (p< 0.00001). None of the locking plate constructs failed prior to the 300,000 cycle end point. In stark contradistinction, all of the non-locked contructs failed at an average cycle count of only 9,541 (range 1,000 – 23,000 cycles). The failure mode for each of the non-locked constructs was pull-out of the distal screws.

Conclusion: These results indicate that the use of a thin plate with locking capability provides a significant advantage over non-locked constructs in fatigue performance in areas of poor bone density subjected to torsional loads, such as the lateral malleolus.

The use of MRI scanning has been described after open reduction of the hip in DDH to check hip position but has not previously been reported after open reduction with femoral osteotomy and the use of metalwork. We performed a prospective study utilising MRI to document the adequacy of reduction.

An MRI scan was performed on the second postoperative day in order to confirm the satisfactory reduction of the hip following surgery. Previously a CT scan was performed.

10 consecutive cases were scanned and all gave diagnostic information of satisfactory reduction. Sedation was not required. The mean scanning time was 3 minute 45 seconds and the total time in the MRI suite ranged from 7 to 10 minutes.

Satisfactory images, the lack of need of sedation, comparable time and cost to CT scanning and most importantly the lack of exposure of the child to ionising radiation make MRI a most appealing method of imaging. We therefore recommend it as the investigation of choice in this patient group.

Demographic data reviewed included gender, MP at time of primary surgery, GMFCS level, age at time of surgery, type of adductor release procedure performed, and experience of surgeon.

Outcome variables assessed were type of subsequent failure, time of failure after primary procedure, and length of follow-up.

Three hundred and thirty children underwent hip adductor surgery. The number of children per GMFCS Level was 33 Level II, 55 level III, 103 level IV, and 139 level V. The average age at time of primary surgery was 4.19 years, mean MP at time of primary surgery 43.16%, and mean length of post-operative follow-up was 7.10 years.

Eighty two children had adductor longus and gracilis lengthening alone, 97 also had an iliopsoas release, 97 had psoas tenotomy and phenolisation of the obturator nerve, and 54 had a psoas tenotomy and neurectomy of the anterior branch of the obturator nerve (in addition to longus & gracilis lengthening).

At time of audit 106 children did not require further surgery (‘surgery success’ of 32%). Thirty one were in children of GMFCS level II (94%), 27 level III (49%), 28 level IV (27%), and 20 level V (14%).

A Cox proportional hazards survivorship analysis was constructed to chart the time course of progression to further surgery over time to reveal statistically significant ‘surgery success’ rates according to GMFCS. Differences in the success rates according to GMFCS become more apparent beyond 3 years post-surgery.

The most important determinant for predicting the success of hip adductor surgery in preventing hip displacement is GMFCS at the time of primary surgery. Current treatment strategies need to be re-evaluated with the context of undertaking long-term post-operative follow up, particularly for children GMFCS levels VI and V.

In a high-risk technically advanced speciality like spine surgery, detailed information about all aspects of possible complications could be frightening for the patients, and thereby increase anxiety and distress. Therefore, aim of this study was to

Analyze written evidence of the consenting procedure pertaining to (a) nature of operation (b) benefits intended as a result of the operation (c) risks specific to the particular type of operation (c) general risks of spine surgery and anaestheia.

Methods: 70 adult elective, consecutive patients who had been listed for Lumbar discectomy /decompression surgery were chosen. The patients were presented with questionnaire of broad-based and open-ended questions designed to elicit theirs views in each of the following areas: expectation, knowledge of risks and alternatives, and personal attitude to information and satisfaction.

The study had a non-randomized design and patients divided into TWO groups Group A and group B.

The patients in the group A received standard information and were consented in a routine way without being given written proforma with all complications. The patients in the group B were given the same information as patients in the control group, with written information about common and rare complications. Patients in both groups were assessed on an ‘impact of events scale’ and hospital anxiety and depression scale immediately before ad after the consent process and again after surgery when they were discharged from the hospital.

For comparison of the proportion of Yes and No answers in 2 groups, Fisher’s exact test was used, and for comparison of more than 2 groups, the Chi-square test was used. For graded answers and other ordinal scales, the Mann–Whitney U-test was used for comparison of 2 groups and the Kruskal–Wallis test for comparison of more than 2 groups. Spearman’s test was used when assessing the correlation between 2 variables measured on an ordinal scale.

Results: Many patients (71%) agreed that the consent form made clear what was going to happen to them, and 77%) reported that it made them aware of the risks of the operation they were to undergo. Over a third (36%) saw it as a safeguard against mixups in the operating theatre. Few patients’ decision to accept surgery appeared to depend on risk information; 8% of patients said that they might have changed their decision, had they been advised of the risks of permanent stroke and myocardial infarction. However, 92% were clear that their decision to accept treatment would not have altered. The women in the group B had symptoms of definite anxiety to a significantly higher degree than the men before the operation. Post-operatively, patients receiving extended information were significantly more satisfied with both the written and oral information about common and rare complications than patients in the control group There were no statistically significant differences between the groups for anxiety or depression, as measured by the HADS, either before or after the operation between Group A and B. Provision of extended information describing most of the possible complications did not have any negative effects on the patients. The patients receiving the extended information were more satisfied and experienced to a higher degree that they could discuss alternative treatment methods with the surgeon. Discussion: Provision of extended information describing most of the possible complications did not have any negative effects on the patients. “Ignorance is bliss” may prove to be an excellent preoperative strategy for patients when outcome is good but detrimental to long term adjustment where significant postoperative complications arise. This raises the possibility that a separate consent could be used where these risks are pre-printed and explained in vocabulary easily understood by patients. The added advantages of this form would be less confusion for the patient and there would be written evidence that patients had understood each of the major risks involved with the proposed procedure. This proposed consent form would also reduce the chance that important risks and complications are omitted when consent is being taken, as well as tackling the issue of variability of experience or lack of knowledge by the person obtaining consent.

Aim: To determine the clinical improvement and the radiological time to fusion as well as correction of the lordosis angle in patients undergoing anterior cervical interbody fusion with the use of a silicate substituted calcium phosphate ceramic (Si-CaP) (Actifuse™ Synthetic Bone Graft, ApaTech, Ltd., Elstree, UK) as the bone graft substitute in the cage.

Design: We conducted a prospective clinical and radiological study to evaluate the use of Si-CaP as bone graft substitute in anterior cervical fusion for degenerative cervical spondylosis.

Materials and methods: Thirty patients were selected prospectively by preoperative and postoperative clinical and radiological assessments. All patients were operated on by a single surgeon (D.A.J.). Neck disability index and visual analogue score were used for the clinical assessment. Radiological assessment included improvement in the lordosis angle and time to fusion. Patients were evaluated at three months, six months and one year post-surgery.

Results: At present 14 patients with a total of 19 levels have completed their one year follow-up. The patients had an average of 50.4 years (range 34–69), with ratio of male to female of 6:7. Lordosis angle improved significantly from a mean lordosis angle of 0.31 preoperatively to 4.75 degree postoperatively (p< 0.05). All the levels had fused at the 1 year follow up and there was no radiological evidence of sinkage of the cage.

Conclusion: Substitution of silicate ions into calcium phosphate ceramics has been shown to impart a negative surface charge, leading to greater protein absorption, increased osteoblast proliferation, and higher production of extracellular matrix. Our results show that Si-CaP has excellent clinical performance as a synthetic bone graft in anterior cervical discectomy and fusion. Postoperatively, patients demonstrate a good fusion with an excellent correction and maintenance of the lordosis angle.

Purpose: Recent animal evidence has suggested that Bupivicaine may be harmful to articular cartilage. The purpose of this study was establish whether, following arthroscopy of the knee, infiltration of Bupivicaine around the portals is as effective as intra-articular infiltration for post-operative analgesia.

Method: Consecutive patients attending for knee arthroscopy were consented and randomised to one of two groups. Following arthroscopy, Group I received 20mls 0.5% Bupivicaine infiltrated into the joint; Group II received 20mls 0.5% Bupivicaine infiltrated around the portals. A Visual Analogue Score (VAS) was collected at one hour post-operatively and rescue analgesia recorded. A power calculation was performed. Ethical approval was granted.

Results: There were 68 patients in Group I (intra-articular) and 69 patients in Group II (portal). There was no significant difference in the age or sex distribution of patients in either group. The mean VAS score was 3.04 in Group I and 3.24 in Group II. There was no significant difference between the two groups (p=0.619). There was also no significant difference in the need for rescue analgesia (p=0.930). The study has demonstrated equivalence between the two groups, within one VAS point (Power = 80%).

Conclusion: We would recommend that following knee arthroscopy, Bupivicaine should be infiltrated around the portals, avoiding intra-articular infiltration.