Introduction

Medial calcaneal displacement osteotomy with an FDL tendon transfer is a common method of correcting pes planus deformity secondary to grade II tibialis posterior dysfunction. There is currently no evidence that calcaneal displacement alters the centre of pressure in the foot from a medial to a more central position as the normal shape is reconstituted.

Background

Despite interest, the current rate of day-case anterior cruciate ligament reconstruction (ACLR) in the UK remains low. Although specialised care pathways with standard operating procedures (SOPs) have been effective in reducing length of stay following some surgical procedures, this has not been previously reported for ACLR. We evaluate the effectiveness of SOPs for establishing day-case ACLR in a specialist unit.

Introduction

Total knee arthroplasty is an established and successful operation. In up to 10% of patients who undergo total knee arthroplasty continue to complain of pain [1]. Recently computerised tomography (CT) has been used to assess the rotational profile of both the tibial and femoral components in painful total knee arthroplasty.

Introduction

In Europe, injectable collagenase clostridium histolyticum (CCH) is a novel, minimally invasive, non-surgical therapy with efficacy in correcting Dupuytren's contracture (DC). We evaluated the efficacy and tolerability of 5 CCH injections using a protocol designed to follow clinical practice.

Introduction

Since the introduction of 3rd generation Metal-on-Metal-Hip-Resurfacing-Arthroplasty (MoMHRA), thousands of such prostheses have been implanted worldwide in younger patients with end-stage hip osteoarthritis. However, no independent centre has reported their medium-to-long term outcome. The aim of this study is to report the ten year survival and outcome of the Birmingham Hip Resurfacing (BHR), the most commonly used MoMHRA worldwide.

ARMD (Adverse Reaction to Metal Debris) is an increasingly recognised complication of metal on metal hip replacements. The MHRA (Medical and Healthcare Related Devices Agency) have advised a blood cobalt or chromium level above 7 mg/L is a threshold for further investigation, stating that “low levels are reassuring and strongly predict not having an adverse outcome”. Cross-sectional imaging should be performed when levels are above 7 mg/L. We have performed a study investigating the specificity and sensitivity of chromium and cobalt metal ion levels as a screening measure for ARMD.

79 ASR hip replacements were performed at our hospital and 75 (95%) of these underwent a Metal Artefact Reduction Sequence (MARS) MRI scan. All patients (64 hips) who had not undergone revision were invited to take part in this study. 57 patients with 62 hip replacements completed hip and activity scores, had blood cobalt and chromium ion level measurements and 3D-CT to measure acetabular component position.

Acetabular component inclination (>50 degrees), small head size (< 51mm) and female gender were significantly correlated with raised chromium (Cr) and cobalt (Co) ion levels. An ARMD was detected using MRI in 18 (29%) of the hips in this study. The incidence of ARMD was significantly higher when chromium concentration was above 7 mg/l (p = 0.02). Chromium ion levels >7 mg/L had a sensitivity of 56% and specificity of 83% for ARMD, and cobalt ion levels >7 mg/L 56% and 76% respectively. 40 patients had cobalt levels <7 mg/L and 33 had chromium levels <7 mg/L, but 8 of these had an ARMD on MRI. All 8 patients had minimal symptoms (Oxford Hip Score ≥ 44 out of 48).

The Medicines and Healthcare Products Regulatory Agency (MHRA) has recommended that cobalt and chromium levels be measured in patients with a metal-on-metal hip replacement and cross-sectional imaging performed when these levels are above 7 μg/L. This study has shown that by using this threshold, in patients with this implant combination, the sensitivity and specificity for the detection of ARMD is low and patients with soft tissue disease may be missed. Furthermore the presence of MRI detected ARMD, in the absence of significant clinical symptoms and with metal ion levels <7 μg/L is of concern.

MoM implants at risk of failure are associated with raised cobalt and chromium levels. However metal ion analysis alone is not reliable as a screening tool for ARMD, which is often clinically “silent”. We recommend the routine use of MARS MRI as the safest method of ARMD diagnosis in patients with MoM implants.

We describe the results for the management of chronic osteomyelitis in long bones using a new single stage procedure, the Cardiff technique. Fourteen consecutive patients were treated prospectively. The patients had a mean age of 52; all patients had a mean stay in hospital of 5 days with outpatient dressings. All patients had tibial fractures, 2 were infected non unions. The origin of infection was traumatic in 13 cases and haematogenous in 1 case. This one stage procedure or The Cardiff technique, uses techniques described by both Papineau's 3 stage method and Lautenbach's procedure. It involves removal of all avascular and infected tissue via marginal debridement, opening of the medullary cavity proximally and distally, compartmental debridement and copious saline irrigation. The wound is then packed with Jelonet and kaltostat and fresh dressings applied weekly. The wound is left to heal via secondary intention. There is no routine use of antibiotics. Antibiotics were only used when required, i.e. Clinical evidence of cellulitis or infection. 11 patients healed with no further surgery, no skin grafting, no bone grafting and no flap coverage. Mean time to healing was 5 months; both non unions united giving results similar to other accepted techniques. There were 3 residual infections, 2 due to inadequate debridement which required a single further compartmental debridement (Lautenbach method), 1 had an avascular bone edge requiring further local debridement. We feel this procedure confers the following advantages; minimal surgical insult, early discharge, out patient management, good outcomes and most importantly, high patient satisfaction. It also serves as a reminder that simple wounds do well with simple solutions.

Introduction

The superficial anterior vasculature of the knee is variably described; most of our information comes from anatomical literature. Descriptions commonly emphasise medial-dominant genicular branches of the popliteal artery. Quantifying the relative contribution of medial and lateral vessels to the anastomotic network of the anterior knee may help provide grounds for selecting one of a number of popular incisions for arthrotomy.

Data was collected on 139 eligible patients a minimum of 18 months post surgery who had had 2 or more ligaments reconstructed. 63 patients were available for clinical follow up. It is the largest single surgeon series studied.

27% of injuries were high energy traffic accidents. 73% were low energy, mainly sports related. 63% of patients were delayed referrals to our unit. Of these nearly 48% had already undergone knee surgery, often more than 6 months post injury. 17% of all cases presented with failed ligament reconstructions. Of those patients followed up 19% were operated upon within 3 weeks of injury, 56% were delayed reconstructions with a mean time to surgery of 21 months and 25% were revision reconstructions. Time to follow up ranged from 18 months to 10 years.

The median KOS ADL, KOS Sports Activity and Lysholm scores for uni-cruciate surgery were all better than those for bi-cruciate surgery. All results were better for acute rather than chronic cases, which in turn were better than those for revision cases. The Tegner score showed that only acute uni-cruciate reconstructions returned to their pre-injury level.

TELOS stress radiographs demonstrated a mean post drawer of 5.9 mm side-to-side difference after reconstructions involving the PCL. IKDC grades showed 6% of knees were normal and 57% were nearly normal.

37% required further surgery, mainly to increase movement or for hardware removal. There was 1 deep infection and 2 cases of thrombosis. There were no vascular complications but 2 had transient nerve injuries.

Multi-ligament surgery can produce good functional outcomes but the knee is never normal. There is an increased risk of PCL laxity post op. Early referral to a specialist unit is suggested as delayed referral to a specialist unit potentially subjects the patient to unnecessary surgery and may affect outcome.

Although chondrocytes have been used for autologous implantation in defects of articular cartilage, limited availability and donor-site morbidity have led to the search for alternative cell sources. Mesenchymal stem cells from various sources represent one option. The infrapatellar fat-pad is a promising source. Advantages include low morbidity, ease of harvest and ex-vivo evidence of chondrogenesis. Expansion of MSCs from human fat-pad in FGF-2 has been shown to enhance chondrogenesis. To further elucidate this process, we assessed the role of TGF-?3, FGF-2 and oxygen tension on growth kinetics of these cells during expansion.

Introduction

Malalignment of some designs of stem is associated with an increased risk of aseptic loosening and revision. We investigated whether the alignment of the cemented polished, double-taper design adversely affected outcome, in a multicentre prospective study.

Purpose

The presence of a Hill-Sachs lesion is a major contributor to failure of surgical intervention following anterior shoulder dislocation. The relationship between lesion size, measured on pre-operative MRI, and risk of recurrent instability after surgery has not previously been defined.

Hypothesis: We hypothesized that the size of Hill-Sachs lesions on pre-op MRI would be greater among patients who failed soft tissue stabilization when compared to patients who did not fail. We also hypothesized that the existence of a glenoid lesion would lead to failure with smaller Hill-Sachs lesions.

INTRODUCTION

Symptomatic hip disorders associated with cam deformities are routinely treated with surgery, during which the deformity is resected in an effort to restore joint range of motion, reduce pain, and protect the joint from further degeneration. This is a technically demanding procedure and the amount of correction is potentially critical to the success of the procedure: under-resection could lead to continued progression of the OA disease process in the joint, while over-resection puts the joint at risk for fracture. This study compares the accuracy of a new robotically assisted technique to a standard open technique.

Introduction

Despite the lack of robust evidence, numerous different track and trigger warning systems have been implemented. The MEWS (Modified Early Warning Score system) is one such example, and has not been validated in an emergency traumasetting. A considerable proportion of trauma admissions are elderly patients with co-morbidities. Early recognition of physiological deterioration and prompt action could therefore be lifesaving.

Electromagnetic navigation versus conventional Total Knee Arthroplasty: Clinical improvements Optical and electromagnetic (EM) tracking systems are widely used commercially. However in orthopaedic applications optical systems dominate the market. Optical systems suffer from deficiencies due to line of sight. EM trackers are smaller but are affected by metal. The accuracy of the two tracker systems has been seen to be comparable1. Recent advancements in optical navigated TKA have shown improved overall limb alignment, implant placement and reduce outliers when compared to conventional TKA2-4.

This study is the first RCT to compare EM and conventional TKA. Two groups of 100 patients underwent TKA using either the EM navigation system or the conventional method. Frontal, sagittal and rotational alignment was analysed from a CT scan. Clinical scores including Oxford Knee Score (OKS) and Knee/Function American Knee Society Score (AKSS) were recorded pre-op, and at 3 and 12 months post-op. 3 month data presented includes 180 patients (n = 90). The 12 months data presented includes 140 (n = 70).

The two groups had similar mean mechanical axis alignments (EM 0.31o valgus, conventional 0.15o valgus). The mechanical axis alignment was improved in the EM group with 92% within +/-3o of neutral compared to 84% of the conventional group (p = 0.90). The alignment of the EM group was improved in terms of frontal femoral, frontal tibial, sagittal femoral, sagittal tibial and tibial rotation alignment. However, only the sagittal femoral alignment was significantly improved in the EM group (p = 0.04). Clinically, both TKA groups showed significant improvements in OKS and AKSS scores between both pre-op to 3 month post-op and 3 months to 12 months post-op (p<0.001). The OKS and the AKSS knee score for the EM group was significantly better at 3 months post-op (OXS p = 0.02, AKSS knee p = 0.04). However there was no difference between the groups at 12 months. The mean pre-op range of motion (ROM) for both groups was 105o. This decreased to 102o in the EM group and 99o in the conventional group at 3 months. There was a significant improvement at 12 months post-op, EM = 113o (p = 0.012) and conventional = 112o (p = 0.026). There was no significant difference in ROM between the two groups at 3 or 12 months post-op.

Therefore the alignment outcome of the EM TKA group was improved compared to the conventional group. The EM group also showed clinical improvements at 3 months post-op however these were not seen again at 12 months post-op. ROM was seen to decrease at 3 months post-op but then significantly improve by 12 month post-op.

Introduction

Iliac crest bone marrow aspirate (ICBMA) is frequently cited as the ‘gold-standard’ source of MSCs. Mesenchymal stem cells have been shown to reside within the intramedullary (IM) cavities of long-bones and a comparative assessment with ICBMA has not yet been performed.

INTRODUCTION

Studies have suggested that there is a reduction in head-neck-ratio (HNR) associated with MoMHRA. A reduction in HNR at operation would decrease range of movement and increase impingement risk. Impingement could lead to 20 edge loading, increasing wear. Serum ion levels of Chromium (Cr) and Cobalt (Co) are surrogate markers of wear. Although acetabular component orientation has been shown to contribute to wear and PT development, the role of a decrease in HNR has only been highlighted in PT development. This study aimed to measure changes in HNR that occur at resurfacing and determine any gender- and component size-specific differences. In addition it aimed to determine whether changes in HNR could be associated with increased wear.

INTRODUCTION

Although simulation studies have shown superior wear properties of metal-on-metal articulations, increased concern exists regarding the excess in-vivo wear of a small number of Metal-on-Metal-Hip-Resurfacing (MoMHRA) implants. Serum ion levels of Chromium (Cr) and Cobalt (Co) are surrogate markers of wear. Risk factors associated with increased wear include female gender, small components, dysplasia, cup orientation outside safe zone and femoral head downsize during surgery with an associated decrease in Head-Neck-Ratio (HNR). However, these factors are interlinked. This study aims to identify the factors that are most important for subsequent wear of MoMHRA, by performing a multivariate analysis.

INTRODUCTION

The introduction of hard-on-hard bearings and the consequences of increased wear due to edge-loading have renewed interest in the importance of acetabular component orientation for implant survival and functional outcome following hip arthroplasty. Some studies have shown increased dislocation risk when the cup is mal-oriented which has led to the identification of a safe-zone1. The aims of this prospective, multi-centered study of primary total hip arthroplasty (THA) were to: 1. Identify factors that influence cup orientation and 2. Describe the effect of cup orientation on clinical outcome.

Tibial eminence fractures were historically thought of as a condition of skeletal immaturity. Increasingly this injury has been recognized in adults.

The aim was to report on the demographics, mechanism, treatment and outcomes of this injury in adult and paediatric patients.

A retrospective review of all patients presenting to Dunedin Hospital, for management of a displaced tibial eminence fracture, between 1989 and 2009.

19 cases were identified, 10 skeletally mature and 9 skeletally immature. Alpine skiing with a forced flexion and rotation injury accounted for 7 cases, primarily adult females (5 cases). A hyper-extension and rotation injury accounted for 7 cases, primarily in skeletally immature males (4 cases), while direct trauma accounted for 5 cases, primarily males (4 cases).

Associated injuries were more commonly seen in adults and those with high energy trauma. Stiffness was the most common complication (10 cases). Tibial spine fractures are more common in adults than previously thought. Female skiers appear to be a group at particular risk. Our most common complication was stiffness. Early range of motion is essential to reduce the problem of stiffness and extension impingement. Laxity is an infrequent problem in adults and children.

Open cheilectomy is an established surgical treatment for hallux rigidus. Cheilectomy is now being performed using minimally invasive(MIS) techniques. In this prospective study we report the outcome of minimally invasive cheilectomy comparing the results with a matched group who had cheilectomy using standard open procedure.

Prospective study of 47 patients. 22 patients had MIS cheilectomy between March 2009 and September 2010. We compared the outcome with a matched group (25 patients) who had open cheilectomy. Functional outcome was assessed using the Manchester Oxford Foot and ankle questionnaire (MOXFQ). The MOXFQ is a validated 16-item, patient-generated questionnaire designed to be self-completed and used as an outcome measure for foot surgery. It comprises three domains foot pain, walking and standing problems and social interaction. Total score ranges from 0 (best score) to 64 (worst score). Patients completed preoperative and postoperative questionnaires. Patients’ satisfaction and complications were recorded.

In the MIS group, the median follow up was 11 months (4–23. The median preoperative MOXFQ score was 34/64(23) and the median postoperative score was 19/64 (p value <0.02) In the open group the median follow up was 17 months (9–27). The median preoperative MOXFQ score was 35/64 and the median postoperative score was 7.5/64 and this difference was statistically significant (<0.0001). There were three failures in the open group (Fusion) compared to none in the MIS.

MIS cheilectomy is an effective alternative procedure with satisfactory functional outcome and high patient satisfaction. Results are comparable to the standard open cheilectomy with a lower apparent failure rate. The results of our randomised controlled trial comparing MIS cheilectomy to open cheilectomy are awaited.

We present the results of a bi-centre, retrospective study examining the clinical, functional and radiological outcomes of distal radius fracture fixation with the Aptus locking plates and Tri-Lock® variable angle locking screws. We assessed 61 patients with distal radius fractures with a minimum of six months follow-up. Functional assessment was made using the DASH score. We measured wrist range of movement and grip strength, and reviewed radiographs to assess restoration of anatomy, fracture union and complications. All fractures united within six weeks. Mean ranges of movement and grip strength were only mildly restricted compared to the normal wrist. The mean DASH score was 18.2. Seven patients had screws misplaced outside the distal radius although 3 of these remained asymptomatic. Five other patients developed minor complications. Variable angle locking systems benefit from flexibility of implant positioning and may allow enhanced inter-fragmentary reduction for accurate fixation of intra-articular fractures. However, variable-angle systems may lead to increased rates of screw misplacement.

The aim of this study was to determine whether the clinical outcome of autologous chondrocyte transplantation was dependent on the timing of a high tibial osteotomy in tibio-femoral mal-aligned knees. Between 2000 and 2005, forty-eight patients underwent autologous chondrocyte implantation with HTO performed at varying times relative to the second stage autologous chondrocyte implantation procedure. 24 patients had HTO performed simultaneously with their second stage cartilage transplantation, (the HTO Simultaneous Group). 5 patients had HTO prior to their cartilage procedure, (the HTO pre-ACI Group) and 19 had HTO performed between 1 to 4 years after their second stage cartilage implantation, (the HTO post-ACI Group). There were 29 men and 19 women with a mean age of 37 years (Range 28 to 50) at the time of their second stage procedure.

With average follow-up of 72 months we have demonstrated a significant functional benefit in performing the HTO either prior to or simultaneously with the ACI procedure in the mal-aligned knee. The failure rate in the Post-ACI group was 45% compared to the Pre-ACI and Simultaneous group, with failure rates of 20% and 25%, respectively.

An HTO performed prior to or simultaneously with an autologous chondrocyte implantation procedure in the mal-aligned knee, provides a significant protective effect by reducing the failure rate by approximately 50%.

Recent approaches have sought to harness the potential of stem cells to regenerate bone lost as a consequence of trauma or disease. Bone marrow aspirate (BMA) provides an autologous source of skeletal stem cells (SSCs) for such applications, however previous studies have demonstrated that the concentration of SSCs present in iliac crest BMA is below that required for robust bone regeneration. Here we present a novel acoustic-facilitated filtration strategy to concentrate BMA for SSCs, clinically applicable for intra-operative orthopaedic use.

The aim of this study was to demonstrate the efficacy of this strategy in concentrating SSCs from iliac crest bone marrow, as well as femoral canal BMA from older patients.

Iliac crest BMA (Lonza, Rockville, MD, USA) and femoral canal BMA was obtained with informed consent from older patients during total hip replacement. 5 to 40ml of BMA was processed via the acoustically-aided exclusion filtration process to obtain 2-8 fold volume reductions. SSC concentration and function was assessed by flow-cytometry, assays for fibroblastic colony-forming units (CFU-F) and multi-lineage differentiation along chondrogenic, osteogenic and adipogenic pathways examined. Seeding efficiency of enriched and unprocessed BMA (normalised to cell number) onto allograft was assessed.

Iliac crest BMA from 15 patients was enriched for SSCs in a processing time of only 15 minutes. Femoral BMA from 15 patients in the elderly cohort was concentrated up to 5-fold with a corresponding enrichment of viable and functional SSCs, confirmed by flow cytometry and assays for CFU-F. Enhanced osteogenic (P<0.05) and chondrogenic (P<0.001) differentiation was observed using concentrated aspirate, as evidenced by biochemical assay and semi-quantitative histological analysis. Furthermore, enhanced cell seeding efficiency onto allograft was seen as an effect of SSC concentration per ml of aspirate (P<0.001), confirming the utility of this approach for application to bone regeneration.

The ability to rapidly enrich BMA demonstrates potential for intra-operative application to enhance bone healing and offers immediate capacity for clinical application to treat many scenarios associated with local bone stock loss. Further in vivo analysis is ongoing prior to clinical tests.

Background

Skeletal stem cells can be combined with human allograft, and impacted to produce a mechanically stable living bone composite. This strategy has been used for the treatment of femoral head avascular necrosis, and has been translated to four patients, of which three remain asymptomatic at up to three year follow-up. In one patient collapse occurred in both hips due to widely distributed and advanced AVN disease, necessitating bilateral hip arthroplasty. However this has provided the opportunity to retrieve the femoral heads and analyse human tissue engineered bone.

Plasma levels of cobalt and chromium ions and Metal Artefact Reduction Sequence (MARS)-MRI scans were performed on patients with 209 consecutive, unilateral, symptomatic metal-on-metal (MoM) hip arthroplasties. There was wide variation in plasma cobalt and chromium levels, and MARS-MRI scans were positive for adverse reaction to metal debris (ARMD) in 84 hips (40%). There was a significant difference in the median plasma cobalt and chromium levels between those with positive and negative MARS-MRI scans (p < 0.001). Compared with MARS-MRI as the potential reference standard for the diagnosis of ARMD, the sensitivity of metal ion analysis for cobalt or chromium with a cut-off of > 7 µg/l was 57%. The specificity was 65%, positive predictive value was 52% and the negative predictive value was 69% in symptomatic patients. A lowered threshold of > 3.5 µg/l for cobalt and chromium ion levels improved the sensitivity and negative predictive value to 86% and 74% but at the expense of specificity (27%) and positive predictive value (44%).

Metal ion analysis is not recommended as a sole indirect screening test in the surveillance of symptomatic patients with a MoM arthroplasty. The investigating clinicians should have a low threshold for obtaining cross-sectional imaging in these patients, even in the presence of low plasma metal ion levels.

Background and objectives

Fracture healing represents a physiological process regulated by a variety of signalling molecules, growth factors and osteogenic progenitor cells. Bone healing following trauma is associated with increased serum concentrations of several pro-inflammatory and angiogenic growth factors1. Platelet-derived growth factor (PDGF) has been shown to stimulate mesenchymal stem cell (MSC) proliferation in vitro. However, the in vivo relationship between the levels of PDGF and the numbers of MSCs in humans has not yet been explored. The aim of this study was to investigate PDGF release in the peripheral circulation following trauma and to correlate it with the numbers of MSCs in iliac crest bone marrow (BM) aspirate and in peripheral blood.

Periprosthetic femoral fractures can occur as a complication of total hip arthroplasty and are often challenging to treat as the mechanical scenario is influenced by the presence of the metal prosthesis within the bone. This research focuses on finding the optimum fixation for transverse, Vancouver type B1 periprosthetic fractures, stabilised using locking plates and secured using screws. The aim of this study was to experimentally validate a computer model of a human femur, develop that model to represent a periprosthetic femoral fracture fixation and show how the model could be used to indicate differences between plating techniques.

In the first development stage, both a laboratory model and a finite element model were developed to evaluate the mechanical behaviour of an intact composite femur under axial loading. Axial strains were recorded along the medial length of the femur in both cases and compared to provide validation for the computational model predications. The computational intact femur model was then modified to include a cemented total hip replacement, and further adapted to include a periprosthetic fracture stabilised using a locking plate, with unicortical screws above, and bicortical screws below the transverse fracture.

For the intact femur case, the experimental and computational strain patterns correlated well with an average difference of 16%. Following the inclusion of the stem, there was a reduction in the strain in the region of the prosthesis reducing by an average of 45%. There was also a large increase in bulk stiffness with the introduction of the prosthesis. When the fracture and plate fixation were included, there was little difference in the proximal strain where the stem dominated, and the strains in the distal region were found to be highly sensitive to the distribution of the screws.

The results of this study indicate that screw configuration is an important factor in periprosthetic fracture fixation. A laboratory model of the periprosthetic facture case is now under development to further validate the computational models and the two approaches will then be used to determine optimum fixation methods for a range of clinical scenarios.

Long bone fractures are a commonly presented paediatric injury. Whilst the possibility of either accidental or non-accidental aetiology ensures significant forensic relevance, there remain few clinical approaches that assist with this differential diagnosis. The aim of this current study was to generate a reproducible model of spiral fracture in immature bone, allowing investigation of the potential relationship between the rotational speed and the angle of the subsequent spiral fracture.

Seventy bovine metacarpal bones were harvested from 7 day old calves. Sharp dissection ensured removal of the soft tissue, whilst preserving the periosteum. The bones were then distributed evenly before eleven groups, before being aligned along their central axis within a torsional testing machine. Each group of bones were then tested to failure at a different rotational speed (0.5, 1, 15, 20, 30, 40, 45, 60, 75, 80 and 90 degrees s-1). The angle of spiral fracture, relative to the long axis, was then measured, whilst the fracture location, the extent of comminution and periosteal disruption, were all recorded.

Sixty-two out of 70 specimens failed in spiral fracture, with the remaining tests failing at the anchorage site. All bone fractures centred on the narrowest waist diameter, with 5 specimens (all tested at 90 degrees s-1) demonstrating comminution and periosteal disruption. The recorded spiral fracture angles ranged from 30 - 45 degrees, and were dependant on the rotational speed.

This study has established a relationship between the speed of rotation and the angle of spiral fracture in immature bovine bone. It is anticipated that further study will enable investigation of this trend in paediatric bone, ultimately providing an additional diagnostic tool for clinicians trying to verify the proposed mechanism of injury.

Purpose

Retrospective review of fusion rates using Grafton DBM/allografts only in AIS.

Purpose

Retrospective review of growth sparing spinal instrumentation.

Patients with hip fracture are at high risk of venous thromboembolism (VTE). Chemical thromboprophylaxis with low molecular weight heparin (LMWH) is associated with a risk of major bleeding in certain patient groups, such as those with renal failure. In these patients, unfractionated heparin should be used. Our aim was to determine the practice of VTE risk assessment in patients admitted with hip fracture against the national guidance, which states that all should have VTE risk assessment on admission. We also assessed the impact of introducing the VTE risk assessment form on prescribing practice of chemical thromboprophylaxis in patients with renal failure.

Prospective audit of patients of 50 patients admitted with hip fracture from 4/8/10 with re-audit of 50 patients admitted from 17/2/2011 after introducing the VTE risk assessment form into the hip fracture admissions proforma. Retrospective analysis was undertaken to determine chemical thromboprophylaxis prescribing in patients with eGFR <30ml/min/1.73m².

Patient demographics were comparable in both audit loops, with the mean age being equal (84 years) and an equal majority of female patients (76%). There were similar numbers of patients with eGFR <30ml/min/1.73m² in both audit loops with 8% (n=4) in the initial audit, and 10% (n=5) in the re-audit. Frequency of VTE risk assessment significantly increased from 16% to 86% after including the VTE risk assessment form in the hip fracture proforma (p<0.0001). Despite this, there was no significant reduction in prescribing of LMWH in patients with renal failure with eGFR <30ml/min/1.73m², (P=0.52).

Documentation of VTE risk assessment in patients admitted with hip fracture can be improved by simple measures such as inclusion of the VTE risk assessment form in the admissions proforma. However, this did not result in a reduction of LMWH prescribed in patients with significant renal failure and risk of major bleeding.

The purpose of this study was to determine the accuracy of MRI scan for the detection of meniscal pathology in our unit. There are published data which show that both sensitivity and specificity can approach 90% when compared to arthroscopic findings.

We retrospectively analysed a single surgeon series of 240 scopes for all indications The arthroscopic reports included an outline diagram of the meniscus upon which the surgeon recorded operative findings. 112 of these patients had also had recent MRI.

We looked at whether the MRI report showed a tear, and this was graded Y/N. The arthroscopic report was graded for tear: Y/N. 66 patients had a positive scan. 64 of these were found to have a tear at surgery. 37 scans were reported as “no tear”, of which 4 were found to have a tear at surgery. Nine scans were not easy to classify as they were descriptive.

In our series of 112 knees, MRI was 90.5% sensitive, 89.5% specific and 90.1% accurate.

When a definite diagnosis of “tear”, or “no tear” was made at scan, there were two false positives and four false negatives. False positives may be unnecessarily exposed to the risks of surgery. Patients with negative scans had a mean delay to surgery of 33 weeks compared to 18 weeks for patients with positive scans. False negatives may wait longer for their surgery. Two of the false negative scans clearly showed meniscus tears which were missed by the reporting radiographer. In our series the scan itself was more accurate than the reporting. It is important to have an experienced musculoskeletal radiologist to minimise the number of missed tears. It is also important for surgeon to check the scan as well as the report.

Recent advancements in optical navigated TKA have shown improved overall limb alignment, implant placement and reduced outliers compared to conventional TKA. This study represents the first RCT comparing EM navigation and conventional TKA. 3D alignment was analysed from CT scans. Clinical scores (Oxford Knee Score (OKS) and American Knee Society Score (AKSS)) were recorded at pre-op, 3 and 12 months post-op. Data presented includes 180 patients (n=90 per group) at 3 months and 140 (n=70 per group) at 12 months.

The groups had similar mean mechanical axis alignments (EM 0.31° valgus; conventional 0.15° valgus). Mechanical axis alignment however was improved in the EM group with 92% within +/−3° of neutral compared to 84% of the conventional group (p=0.90). The EM group showed improved coronal and sagittal femoral alignment and improved coronal, sagittal and rotational tibial alignment, which was significant for sagittal femoral alignment (p=0.04). The OKS and AKSS scores were significantly better for the EM group at 3 months post-op (OKS p=0.02, AKSS p=0.04), but there was no difference between groups at 12 months. The mean pre-op range of motion (ROM) for both groups was 105°. This decreased at 3 months to 102° in the EM group and 99° in the conventional group, but there was a significant improvement by 12 months: EM=113° (p=0.012) and conventional=112° (p=0.026). ROM was statistically similar between groups at all assessment phases.

Knee alignment was better restored following EM navigated TKA relative to conventional TKA, but the difference was not significant. The EM group showed greater clinical improvements at early follow-up; however this difference was not sustained at 12 months. ROM was seen to decrease at 3 months but then significantly improve by 12 month post-op. Proving cost-effectiveness for navigation systems in TKA remains a challenge.

Purpose

To establish the reliability of reporting and recording revision hip and knee arthroplasties by comparing data in the National Joint Registry (NJR), Hospital Episode Statistics (HES) and our local theatre records.

Total knee arthroplasty (TKA) is an established and successful operation. However patient satisfaction rates vary from 81 to 89% 1,2,3. Pain following TKA is a significant factor in patient dissatisfaction 1. Many causes for pain following total knee arthroplasty have been identified 4 but rates of unexplained pain vary from 4 to 13.1% 5,6. Recently computerised tomography (CT) has been used to assess the rotational profile of both the tibial and femoral components in painful TKA

We reviewed 57 patients with an unexplained painful following TKA and compared these to a matched control group of 60 patients with TKA. Datum gathered from case notes and radiographs using a prospective database to identify patients. The CT information recorded was limb alignment, tibial component rotation, and femoral component rotation and combined rotation.

The two matched cohorts of patients had similar demographics. A significant difference in tibial, femoral and combined component rotation was identified between the groups. The following mean rotations were identified for the painful and control groups respectively. Tibial rotation was 3.46 degrees internal rotation (IR) compared to 2.50 degrees external rotation (ER)(p=0.001). Femoral rotation was 2.30 IR compared to 0.36 ER(p=0.02). Combined rotation was 7.08 IR compared to 2.85 ER(p=0.001).

This is the largest study presently in the literature. We have identified significant internal rotation in a patient cohort with unexplained painful TKA when compared to a matched control group. Internal rotation of the tibial component, femoral component and combined rotation was identified as a factor in unexplained pain following TKA.

Aim

To determine the tensile forces across the knee extensor mechanism during walking, in simulated conditions of treatment.

Purpose of the study

This study was undertaken to evaluate the early results of a new implant system - the metaphyseal sleeve - in revision total knee replacement. The femoral and tibial metaphyseal sleeves are a modular option designed to deal with metaphyseal bone loss and achieve cementless fixation over a relatively wide area in the metaphysis.

This review summarises the opinions and conclusions reached from a symposium on infected total knee replacement (TKR) held at the British Association of Surgery of the Knee (BASK) annual meeting in 2011. The National Joint Registry for England and Wales reported 5082 revision TKRs in 2010, of which 1157 (23%) were caused by infection. The diagnosis of infection beyond the acute post-operative stage relies on the identification of the causative organism by aspiration and analysis of material obtained at arthroscopy. Ideal treatment then involves a two-stage surgical procedure with extensive debridement and washout, followed by antibiotics. An articulating or non-articulating drug-eluting cement spacer is used prior to implantation of the revision prosthesis, guided by the serum level of inflammatory markers. The use of a single-stage revision is gaining popularity and we would advocate its use in certain patients where the causative organism is known, no sinuses are present, the patient is not immunocompromised, and there is no radiological evidence of component loosening or osteitis.

It is our opinion that single-stage revision produces high-quality reproducible results and will soon achieve the same widespread acceptance as it does in infected hip arthroplasty.

The superficial anterior vasculature of the knee is variably described; most of our information comes from anatomical literature. Descriptions commonly emphasise medial-dominant genicular branches of the popliteal artery. Describing the relative contribution of medial and lateral vessels to the anastomotic network of the anterior knee may help provide grounds for selecting one of a number of popular incisions for arthrotomy.

The aim of this study is to describe the relative contribution of vessels to anastomoses supplying the anterior knee.

Cadaveric knees (n = 16) were used in two cohorts. The first cohort (n = 8) were injected at the popliteal artery with a single colour of latex, and then processed through a modified diaphanisation technique (chemical tissue clearance) before final dissection and analysis. This was repeated for the second cohort, but with initial dissection to identify potential source vessels at their origin. Each source vessel was injected with a different colour of latex. The dominant sources were determined in each specimen.

The majority of the specimens (n = 13; 81%) demonstrated that an intramuscular branch though the vastus medialis muscle was the dominant vessel. Anastomoses were most common over the medial side of the knee, both superiorly and inferiorly (3-5 anastomoses in all cases). Anastomosis over the lateral knee was infrequent (1 anastomosis in 1 specimen).

The results suggest that anterior vasculature of the knee is predominately medial in origin, but not from the genicular branches as previously described. This network of vessels found in the anterior knee is thought to be the main supply to the patella, extensor apparatus, anterior joint capsule and skin.

Optimum placement of incision for arthrotomy is a subject of debate. Considering the main blood supply to the anterior knee may help in choosing a particular approach.

Cognitive impairment is common in patients with hip fracture both on admission and may develop later on. Reduced cognitive function is a risk factor for development of delirium, correlates with poor rehabilitation, and is an independent predictor of increased mortality. Despite its commonplace and potential for serious morbidity, cognitive dysfunction is often poorly assessed & diagnosed.

Our aims were to 1) assess the practice of cognitive assessment on admission for hip fracture patients according to local guidelines and 2) ascertain whether it can be improved by the formal introduction of Abbreviated Mental Test Score (AMTS) & Clock Drawing Test (CDT) in the hip fracture admission proforma.

A prospective audit was undertaken of cognitive assessment by either AMTS or CDT for 50 consecutive patients admitted with hip fracture from 4/8/2010. Subsequently, the hip fracture admission proforma was amended to include both the AMTS & CDT. A re-audit was performed on 50 consecutive patients admitted from 17/2/2011 to determine the change in practice.

Patient demographics were comparable in both audit loops, with the mean age being equal (84 years) and an equal majority of female patients (76%). Cognitive assessment by either AMTS or CDT significant increased from 28% (n=14) to 86% (n=43) in the re-audit (p<0.0001). All AMTS were completed in accordance with instructions, whereas almost half of CDTs were incompletely or incorrectly filled out (45%).

The assessment of cognitive function can be greatly improved by inclusion of both the AMTS & CDT to the hip fracture admission proforma, allowing the most appropriate multi-disciplinary care to be planned for the patient. Whilst both CDT and AMTS are good screening tools for cognitive impairment, many are unfamiliar with CDT & more training is needed.

Full-thickness burns around the knee can involve the extensor mechanism. The gastrocnemius flap is well described for soft tissue reconstruction around the knee. We describe a method where a Whichita Fusion Nail¯ knee arthrodesis, combined with a medial gastrocnemius muscle flap was used to salvage the knee and preserve the lower leg following a full-thickness contact burn.

The gastrocnemius flap for wound coverage of an open knee joint was originally described in 1970 and remains the workhorse for soft tissue knee reconstruction. There are a number of local alternatives including the vastus lateralis, medialis and sartorius flap; and perforator flaps such as the medial sural artery perforator island flap and islanded posterior calf perforator flap, however many of these are unsuitable for larger defects.

Full-thickness burns around the knee can put the extensor mechanism at risk and subsequent rupture is a possible consequence. The gastrocnemius flap has been used to cover a medial knee defect with exposed joint cavity following a burn and also been used in post burn contracture release around the knee.

The primary indication for Wichita fusion nail is a failed total knee replacement. It allows intramedullary stabilization with compression at the arthrodesis site to stimulate bone union. With fusion rates reported up to 100% and low complication rates as compared to other methods of fusion, the technique has a useful role in limb salvage type procedures.

While use of the gastrocnemius flap in knee burns has been described before we believe this is the first time that this combination of techniques, namely knee arthrodesis with soft tissue reconstruction using a gastrocnemius flap, has been reported. Combining these procedures with a multidisciplinary approach provides a useful alternative leading to limb salvage and avoiding the need for an above knee amputation when extensor reconstruction is not possible.

Stem geometry is known to influence the outcome in THA; however it is unknown whether the material properties, stiffness in particular can influence the stem stability and outcome. The aim of this study was to measure the influence of stem material properties on micromotion and migration using Roentgen Stereophotogrammetric Analysis (RSA) system.

41 patients were implanted with a collarless polished tapered (CPT) femoral stem (Zimmer, Warsaw, Indiana), which was made of either cobalt-chromium (CoCr) (n=21) or stainless steel (n=20). RSA was used to measure dynamically inducible micromotion (DIMM: difference in stem position in going from double-leg stance (DLS) to single leg stance (SLS)), prosthesis bending (difference in the head-tip distance when going from DLS to SLS), and mean migration of the head, tip and the cement restrictor. DIMM and bending were measured at 3 months, migration at 6, 12 and 24 months. All analyses were carried out using SPSS for windows (v.15.0.0, Chicago. IL, USA). Results were reported as mean ± 95% confidence interval (CI) and regarded as significant when p < 0.05.

Preliminary analysis showed that total head DIMM was significantly (p = 0.02) greater for CoCr (0.97mm ± 0.6mm) than stainless steel (0.27mm ± 0.6mm). The mean stem bending for CoCr was 0.08mm (± 0.06mm) and for stainless steel 0.15mm (± 0.06mm) (p =0.77). Both implants heads migrated posteriorly, medially and distally. The mean subsidence for the cobalt-chromium and stainless steel stems was 1.02mm (± 0.19mm) (p < 0.001) and 1.12mm (± 0.34mm) (p=0.001) (p= 0.07) at 24 months.

It was interesting to note that the dynamically induced micromotion was greater for the stiffer stem, however there were no differences in terms of overall migration, indicating that survival (in terms of loosening) should be the similar for both steel and CoCr versions of this implant.

Purpose

To evaluate efficacy of blood conservation strategies on transfusion requirements in adult scoliosis surgery and establish a protocol for cross matching.

Total knee arthroplasty is an established and successful operation. In up to 13% of patients who undergo total knee arthroplasty continue to complain of pain. Recently computerised tomography (CT) has been used to assess the rotational profile of both the tibial and femoral components in painful total knee arthroplasty.

We reviewed 56 painful total knee replacements and compared these to 56 matched patients with pain free total knee replacements. Patients with infection, aseptic loosening, revision arthroplasties and gross coronal malalignment were excluded. Datum gathered from case notes and radiographs using a prospective orthopaedic database to identify patients. The age, sex, preoperative and postoperative Oxford scores, visual analogue scores and treatments recorded. The CT information recorded was limb alignment, tibial component rotation, femoral component rotation and combined rotation.

The two cohorts of patients had similar demographics. The mean limb alignments were 1.7 degrees varus and 0.01 degrees valgus in the painful and control groups respectively. A significant difference in tibial component rotation was identified between the groups with 3.2 degrees of internal rotation in the painful group compared to 0.5 degrees of external rotation in the control group (p=0.001). A significant difference in femoral component rotation was identified between the groups with 3.8 degrees of internal rotation in the painful group compared to 1.1 degrees of external rotation in the control group (p=0.001). A significant difference in the combined component rotation was identified between the groups with 6.8 degrees of internal rotation in the painful group compared to 1.7 degrees of external rotation in the control group (p=0.001).

We have identified significant internal rotation in a patient cohort with painful total knee arthroplasty when compared to a control group with internal rotation of the tibial component, femoral component and combined rotation. This is the largest comparison series currently in the literature.

Aim

To investigate the effect of intraoperative wound irrigation with povidone-iodine on surgical site infection.

Frictional resistance to tendon gliding is minimised by surrounding loose areolar tissues. During periods of prolonged immobilisation, for example post tendon-repair, adhesions can form between the two adjacent tissues, thereby limiting function. Whilst agents applied during surgery are recognised to succeed in adhesion prevention, they have also been reported to provide some reduction in friction during in vitro tendon-bony pulley investigations. This study investigated the effectiveness of common anti-adhesion agents in lubricating the tendon-surrounding tissue contact by comparison with a control study. By using a validated apparatus and with reference to the Stribeck curve, it was determined that the natural in vivo contact is likely to be lubricated by a film of synovial-like fluid. Application of all anti-adhesives generated a similarly efficient lubricating system, and hence administration of these agents should be encouraged to all regions of the tendon disrupted during surgery. Minimising frictional resistance to gliding will reduce the likelihood of tendon ‘gapping’ - and subsequently failure - at the repair site.

INTRODUCTION

The risk of dislocation in large diameter metal on metal hip replacement is significantly lower than in standard THR. This is due to the increased primary arc, increased jump distance and possibly a suction effect. Our unit has performed over 1500 of these cases with an overall revision rate of <1%. We report a case series of dislocations in 5 large diameter metal on metal hips undertaken at our unit.

Background

Many Accident and Emergency units employ a “one size fits all” policy with regard to referring patients with musculoskeletal injury for further review in fracture clinic. This may result in inappropriate timings of review in the clinic wasting patient time, clinic time and hospital resources.

Introduction

Anteromedial osteoarthritis of the knee (anteromedial gonarthrosis-AMG) is a common form of knee arthritis. In a clinical setting, knee arthritis has always been assessed by plain radiography in conjunction with pain and function assessments. Whilst this is useful for surgical decision making in bone on bone arthritis, plain radiography gives no insight to the earlier stages of disease. In a recent study 82% of patients with painful arthritis had only partial thickness joint space loss on plain radiography. These patients are managed with various surgical treatments; injection, arthroscopy, osteotomy and arthroplasty with varying results. We believe these varying results are in part due to these patients being at different stages of disease, which will respond differently to different treatments. However radiography cannot delineate these stages. We describe the Magnetic Resonance Imaging (MRI) findings of this partial thickness AMG as a way of understanding these earlier stages of the disease.

AIM

Avascular necrosis (AVN) of the femoral head is a potentially debilitating disease of the hip in young adults. Impaction bone grafting (IBG) of morcellised fresh frozen allograft is used in a number of orthopaedic conditions. This study has examined the potential of skeletal stem cells (SSC) to augment the mechanical properties of impacted bone graft and we translate these findings into clinical practice.

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.

Femoral stem varus has been associated with poorer results. We report the incidence of varus/valgus malalignment of the Exeter polished, double taper design in a multicentre prospective study. The surgical outcomes at a minimum of five year and complication rates are also reported.

A multicentre prospective study of 987 total hip replacements was undertaken to investigate whether there is an association between surgical outcome and femoral stem malalignment. The primary outcome measure was the change in the Oxford hip score (OHS) at five years. Secondary outcomes included the rate of dislocation and revision.

The incidence of varus and valgus malignment were 7.1% and 2.6% respectively. There was no significant difference in OHS between neutral and malaligned femoral stems at 5 years (neutral, mean = 40.2; varus, mean 39.3, p = 0.465; valgus, mean = 40.9, p = 0.605). There was no significant difference in dislocation rate between the groups (p = 0.66). There was also no significant difference in revision rate (p = 0.34).

This study provides evidence that the Exeter stem is extremely tolerant of varus and valgus malalignment, both in terms of outcome and complication rate.

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.

Many of the questionnaire based scoring systems (i.e. Rowe score) require some form of clinical assessment. These clinical components can be very difficult to perform on a large scale particularly when a patient lives a long distance from clinic. We have attempted to counter this problem by asking the patient to asses their own range of motion. The aim of this study was to test the agreement between patient and clinician measured shoulder external rotation range using a photo based self-assessment tool.

Fifty-one professional and semi-professional rugby players were recruited to assess shoulder external rotation range. Each player was presented with a photo based shoulder external rotation range self-assessment tool, which featured four photos of progressive shoulder external rotation in 2 positions, 900 abduction (150, 300, 450 & 600 of external rotation) and 00 abduction (700, 800, 900 & 1000 of external rotation). The players were asked to perform active external rotation in these two positions and mark the image which best matched their maximal external rotation. The player was then independently assessed using the same tool, by a clinician.

The difference between the player's and the clinician's assessment was analysed using a weighted Kappa test. The Kappa for the shoulder external rotation in 900 abduction was 0.75 and 0.71 for left and right respectively, and 0.57 and 0.55 for shoulder external rotation in 00 abduction. Thus, the strength of agreement between the player's and clinician's assessment of shoulder external rotation is good in 900 abduction and moderate in 00 abduction.

These results demonstrate that the photo-based shoulder external rotation range self-assessment tool is a very useful addition to researchers' and clinicians' toolkits and may be most useful when a patient lives a great distance from/or is unable to attend a clinic.

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.

Fracture of a ceramic component in total hip replacement is a rare but potentially catastrophic complication. The incidence is likely to increase as the use of ceramics becomes more widespread. We describe such a case, which illustrates how inadequate initial management will lead to further morbidity and require additional surgery. We present the case as a warning that fracture of a ceramic component should be revised to another ceramic-on-ceramic articulation in order to minimise the risk of further catastrophic wear.

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.

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.

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.

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

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.

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.

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.

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

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.

We obtained pre-operative and six-month post-operative Oxford hip (OHS) and knee scores (OKS) for 1523 patients who underwent total hip replacement and 1784 patients who underwent total knee replacement. They all also completed a six-month satisfaction question.

Scatter plots showed no relationship between pre-operative Oxford scores and six-month satisfaction scores. Spearman’s rank correlation coefficients were -0.04 (95% confidence interval (CI) -0.09 to 0.01) between OHS and satisfaction and 0.04 (95% CI -0.01 to 0.08) between OKS and satisfaction. A receiver operating characteristic (ROC) curve analysis was used to identify a cut-off point for the pre-operative OHS/OKS that identifies whether or not a patient is satisfied with surgery. We obtained an area under the ROC curve of 0.51 (95% CI 0.45 to 0.56) for hip replacement and 0.56 (95% CI 0.51 to 0.60) for knee replacement, indicating that pre-operative Oxford scores have no predictive accuracy in distinguishing satisfied from dissatisfied patients.

In the NHS widespread attempts are being made to use patient-reported outcome measures (PROMs) data for the purpose of prioritising patients for surgery. Oxford hip and knee scores have no predictive accuracy in relation to post-operative patient satisfaction. This evidence does not support their current use in prioritising access to care.

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.

From a global point of view, chronic haematogenous osteomyelitis in children remains a major cause of musculoskeletal morbidity. We have reviewed the literature with the aim of estimating the scale of the problem and summarising the existing research, including that from our institution. We have highlighted areas where well-conducted research might improve our understanding of this condition and its treatment.

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: 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.

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.

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.