Introduction

The addition of hydroxyapatite in cementless total knee arthroplasty is believed to reduce the time for implant fixation and rehabilitation, reduce the incidence of RLLs and provide long lasting implant stability, through improved osseointegration. We report the results of a prospective, randomised controlled single blinded study comparing the post operative pain, biological fixation and clinical outcomes with the LCS Complete Porocoat and the hydroxyapatite-coated, LCS Complete Duofix mobile-bearing knee systems.

Methods

Two hundred and four patients for TKA were prospectively recruited into the study between November 2006 and November 2008. Subjects were randomly assigned to receive the LCS Complete Duofix or LCS Complete Porocoat knee systems. Outcomes including VAS pain scores, American Knee Society scores and Oxford knee scores were performed pre-operatively and at 3 months. X-rays were analysed by an independent reviewer for the presence of radiolucent lines.

Aim

To compare minimally invasive (MIS) and standard surgical total knee replacement technique through a prospective, randomised, single-centre, multi-surgeon, controlled trial.

Methods

Between March 2007 and May 2009, 70 patients undergoing 73 total knee replacements were recruited. 31 operations were randomised to the MIS treatment arm, 42 to the standard control arm. Data were collected for mode of anaesthesia, American Society of Anaesthesiologists' score (ASA), surgical time, Postoperative blood loss within surgical drains, length of stay and complications. Patients underwent surgery via a mini-mid vastus approach or medial parapatella approach (controls). All operations were performed

Introduction

Previous studies comparing cruciate retaining (CR) and cruciate sacrificing - posterior stabilised (PS) TKRs have failed to demonstrate a difference in outcomes based on numbers of patients recruited.

This large study compares clinical outcomes in groups having PS and CR TKR and reports the results at 1 and 2 years post-operatively.

Methods

A total of 683 patients undergoing TKR were consecutively enrolled in a prospective multi-centre study with 2 arms. In the first arm patients receiving a PS component were randomised to receive either a mobile bearing (176 patients) or fixed bearing (176 patients) implant. In the second arm, patients receiving a CR component were randomised to receive either a mobile bearing (161 patients) or fixed bearing (170 patients) implant. All patients were assessed preoperatively and at one and two years postoperatively using standard tools (Oxford, AKSS, Patellar Score) by independent nurse specialists. The data from the 2 arms of the trial were then analysed to compare differences between PS and CR implants.

Methods

110 total knee arthroplasties performed during a 4 year period were included(2005 to 2009). All operations were performed by 2 surgeons. Group 1 used an extramedullary guide with a 0 degree cutting block tilted by placing 2 fingers between the tibia and the extramedullary guide proximally and three fingers distally to produce a 3 degree posterior slope (N=40). Group 2 used computer navigation to produce a 3 degree posterior slope (N=30). Group 3 used an extramedullary guide placed parallel to the anatomic axis of the tibia with a 5 degree cutting block to produce a 5 degree slope (N=40).

Posterior tibial slope was measured by 2 independent blinded reviewers. The reported slope for each sample was the average of these measurements. All statistical calculations were performed using SPSS Windows Version 16.0 (SPSS Inc., IL, USA).

Results

There was excellent agreement for the mean posterior slopes measured by the 2 independent reviewers. The linear correlation constant was 0.87 (p<0.01). The paired t test showed no significant difference (p=0.82).

The measurements for Group 1 (4.15±3.24 degrees) and Group 2 (1.60±1.62 degrees) were both significantly different to the ideal slope of 3 degrees (p=0.03 for Group 1 and p<0.01 for Group 2). The mean posterior tibial slope of Group 3 (5.00±2.87 degrees) was not significantly different to the ideal posterior tibial slope of 5 degrees (p=1.00). Group 2 exhibited the lowest standard deviation.

Introduction

The Oxford Knee Score is a well validated, commonly used scoring system. Previous studies have suggested that the score is influenced by demographic differences between patients in particular the functional component more than the pain and clinical components. The aim of this study was to further assess this using a large number of patients.

Methods

The pre, 3 months and 12 months post-surgical Oxford Knee Scores were collected from 1492 patients from five distinct demographic locations undergoing total knee arthroplasty over twelve years under the care of 8 different consultants. A total of 735 patients had complete data sets. The scores were than analysed to test whether age, postcode, sex or consultant in charge had any significant effects on the outcome.

Background

During 2002-2007 over 300,000 patients underwent knee arthroplasty (KA) in England and Wales, from which 204 cases of litigation were processed costing in excess of £5million. The complications associated with primary KA are well documented, however those instigating litigation in the UK are not known.

This study assessed trends in litigation over the past 5 years identifying instigating factors and success rates to highlight areas for further improvement in patient information and surgical management.

Methods

Data from the NHS Litigation Authority on claims following KA unrelated to trauma between 2002 and 2007 were obtained and analysed.

MATERIALS AND METHODS

Bone cuts were used to balance the valgus knee and soft tissue release was confined to the postero-lateral capsule in severe deformity. The aim was to restore a “functional mechanical axis” as opposed to a “neutral” mechanical axis. All surgeries were performed between Jan2003 and Apr2007, under the care of a single surgeon using an LCS rotating platform. All patients had full length radiographs and outcome scores collected prospectively.

RESULTS

The mean coronal alignment of the lower limb was corrected from 15.9°(10-45°) to 3.8°. 94% patients had their coronal alignment restored to = 7°. Sixteen knees with postoperative valgus ≥8° were analysed as a separate group. The mechanical axis deviation was corrected from 52.3mm to 8.8mm. The distal femoral cut was made at 5° valgus in 131 knees(47.5%), 6° in 111 knees(40.2%) and 7° in 24 knees(8.7%).78 knees(28%) were balanced only with bone cuts. 198 knees(72%) had release of posterolateral capsule. 16 knees(5.8%) also had release of IT band. Lateral patellar release was performed in 39 knees (14%) and 23 knees had patella contouring. 93%knees had central patello-femoral alignment postoperatively. One spinout was managed by closed reduction and a second patient had revision of tibial tray for collapse. Patellar subluxation occurred in two patients. The oxford knee score and the American Knee Society clinical score improved from 48.5 to 26 and 21.04 to 86.03 respectively.

Aim

The aim of this study was to determine the factors which were responsible for differences between patients achieving the Trust target of discharge on post-operative day 5 after a primary total knee replacement and those not achieving it, in the cohort of over 75 year olds.

Methods and Results

Of all the patients undergoing a TKR at Addenbrooke's Hospital in 2008, those over 75 were identified (n=103). From the literature pre-, intra- and post-operative factors that had previously been shown to affect length of stay were identified. Patient notes were examined for details on each of these and the patients divided into 2 groups according to whether their discharge was achieved by day 5 or not. Data from 74 operations was available at the time of submission of this abstract. Pearson's Chi-squared test, student's independent t-test or the Mann-Whitney U test were performed on the data depending on the nature of the variable analysed. The following factors were found to be significantly different between the 2 groups at the 95% confidence level: pre-operative use of a walking aid (p=0.033), pre-operative Hb (p=0.003), post-operative Hb (p=0.001), post-operative requirement of a blood transfusion, post-operative complication (p<0.001), post-operative day on which active knee flexion to 90° was achieved (p=0.003). In addition the following factors were found to be significant at the 90% confidence level: age (p=0.082), comorbidity (p=0.086), marital status (p=0.095) and mobilisation by post-operative day 2 (p=0.082)

Introduction

Mobile-bearing TKRs allow some axial rotation and may provide a more natural patellar movement. The aim was to compare patellar kinematics among the normal knee, fixed-bearing and mobile-bearing TKR.

Methods

Optical computer navigation (Brainlab) was used to track the position of the femur, tibia and patella in 9 whole lower extremities (5 fresh cadavers) in the natural knee, in the same knee with the trial components of a posterior stabilised fixed-bearing TKR (FB) (Sigma PFC, Depuy) and a posterior stabilised mobile-bearing TKR (MB) (Sigma RP Stabilised). The patellae were not resurfaced. Values: mean+/−one standard deviation. Statistical analysis: two tailed paired Student's T-test.

Purpose

We report our initial results of a new comprehensive patient care plan to manage peri-operative pain, enable early mobilisation and reduce length of hospital stay in TKA.

Methods and Results

A prospective audit of 1081 patients undergoing primary TKA during 2008 and 2009 was completed. All patients followed a planned programme including pre-operative patient education, pre-emptive analgesia, spinal/epidural anaesthesia with propofol sedation, intra-articular soft tissue wound infiltration, post-operative high volume intermittent ropivacaine boluses with an intra-articular catheter and early mobilisation. The primary outcome measure was the day of discharge from hospital. Secondary outcomes were verbal analogue pain scores on movement, time to first mobilisation, nausea and vomiting scores, urinary catheterisation for retention, need for rescue analgesia, maximum flexion at discharge and six weeks post-operatively, and Oxford score improvement.

The median day of discharge was post-operative day four. Median pain score on mobilisation was three for first post-operative night, day one and two. 35% of patients ambulated on the day of surgery and 95% of patients within 24 hours. 79% patients experienced no nausea or vomiting. Catheterisation rate was 6.9%. Rescue analgesia was required in 5% of cases. Median maximum flexion was 85° on discharge and 93° at six weeks post-operatively. Only 6.6% of patients had a reduction in maximum flexion (loss of more than 5°) at six weeks. Median Oxford score had improved from 42 pre-operatively to 27 at six weeks post-operatively. The infection rate was 0.7% and the DVT and PE rates were 0.6% and 0.5% respectively.

Background

Total Knee Replacement (TKR) is technically demanding, time consuming and has higher complication rates in super obese (BMI>45) patients. Bariatric surgery can be considered for such patients prior to TKR although its effect on complications is unknown.

Methods

All patients who underwent bariatric surgery and a TKR in the NHS in England between 2005 and 2009 were included. Hospital episode statistics data in the form of OPCS, ICD10 codes were used to establish 90-day DVT, PE and mortality rates (inpatient and outpatient). In addition, readmission to orthopaedics, joint revision and ‘return to theatre for infection’ rates were also established. Code strings for each patient were examined in detail to ensure the correct gastric procedures were selected. Fifty-three patients underwent bariatric surgery then TKR (44-1274 days) (group 1). Thirty-one patients underwent TKR then bariatric surgery (33-1398 days) (group 2).

Aim

This aim of this study was to investigate apoptosis, reactive oxygen species (ROS), and their upstream markers in Anteromedial Gonarthrosis (AMG).

Methods

Ten resection specimens, from patients undergoing unicompartmental knee replacement for AMG, and ten control specimens, collected from vascular disease patients undergoing above knee amputation, were used. Routine histology and immunohistochemical studies were conducted for Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), Active Caspase 3, Cytochrome C, Active Bax, Bim, 3-Nitrotyrosine and Forkhead box O3A (FOXO 3A).

Purposes of the study

To assess the performance of an acellular synthetic scaffold in the treatment of painful partial meniscal tissue loss.

Methods

Subjects recruited (n=52) had irreparable medial or lateral meniscus partial meniscus loss, intact rim, presence of both horns and a stable well aligned knee.

Diagnostic imaging was used to assess tissue ingrowth at 3 months post-implantation by evidence of vascularisation in the scaffold using DCE-MRI with intravenous gadolinium contrast material (n=42). All DCE-MRI scans were assessed centrally for neovascularisation in the peripheral half of the scaffold meniscus and integration of the implanted device. Stability of tissue ingrowth and cartilage scores in the index compartment were assessed at 12 and 24 months post-implantation using anatomic MRI scans.

Introduction

Total knee arthroplasty (TKA) accounts for 84% of all knee replacement surgery in the UK (NJR 2009) despite published epidemiological data showing that single compartment disease is most prevalent. We investigated this incompatibility further by describing the compartmental pattern and stage of cartilage loss of all patients with osteoarthritis (OA) presenting to a specialist knee clinic over one year.

Methods

All new primary referrals in a calendar year by local General Practitioners to knee clinic at a United Kingdom Hospital were assessed. Tertiary referrals and second opinions were excluded. The final diagnosis after all imaging was recorded and tabulated. The standing AP, lateral and skyline radiographs of all cases of arthritis were scored to assess the pattern of disease.

Purpose

To calculate the cost of investigation of a painful Total Knee Replacement (TKR) to the hospital trust and Primary Care Trust (PCT).

Method

28 patients, over a year period, with painful Total Knee replacements were collected. Costs were calculated only of those patients who had an improvement in their symptoms such that they no longer had a painful TKR. The numbers of appointments, number of serological and radiological investigations were calculated along with any further investigations such as aspirations and arthroscopies. Costs were calculated from hospital records and charges to the PCT. An average cost per patient of investigations was calculated

PURPOSE OF STUDY

20-70% of patients need blood transfusion postoperatively. There remain safety concerns regarding allogenic blood transfusion. Tranexamic acid (TA) is a synthetic antifibrinolytic agent that has been successfully used to stop bleeding in other specialties. We applied TA topically prior to the wound closure to find out the effect on blood loss as well as need for subsequent blood transfusion. This method of administration is quick, easy, has less systemic side effect and provides a higher concentration at the bleeding site.

MATERIALS AND METHODS

A double blind randomised controlled trial of 154 patients who underwent unilateral primary cemented total knee replacement. Patients were randomised into tranexamic acid group (1g drug mixed with saline to make up 20mls) or placebo (20ml 0.9% saline). The administration technique and drain protocol was standardised for all patients. Drain output was measured at 24 hours, and both groups compared for need of Blood transfusion. Outcome measures - blood loss, transfusion, complications, Euroqol and Oxford Knee Score.

Introduction

Up to 2% of total knee arthroplasties (TKA) are still complicated by infection. This leads to dissatisfied patients with poor function, and has far-reaching social and economic consequences. The challenge in these cases is the eradication of infection, the restoration of full function and the prevention of recurrence.

We report the outcome of prosthesis sparing early aggressive debridement in the acutely infected TKA.

Methods

We studied 29 consecutive patients referred with acutely infected TKA (18 primaries, 11 revisions) which occurred within 6 weeks of the index operation or of haematogenous spread. Microbiology confirmed bacterial colonisation in all cases with 20 early post-operative infections and 9 cases of acute haematogenous spread. All patients underwent aggressive open debridement, a thorough synovectomy and a change of insert. Antibiotics were continued until inflammatory markers and the plasma albumin concentration returned to within normal limits.

Aim

Analysis of the effect of administration of antibiotics before collection of microbiology samples in patients with septic arthritis of the native and prosthetic knee.

Method and Results

A retrospective analysis of patients admitted to the unit with a diagnosis of septic arthritis of the knee. There were 27 infections in 26 native knees and 27 infections in 26 prosthetic knees. Sixty-three percent of the native knees had received antibiotics prior to collection of microbiology samples. Fifty-three percent of these grew an organism from at least one of their aspirate, washout fluid or swab. Of the 37% that did not have antibiotics 100% grew an organism. There was no difference in the type or length of treatment required between the groups. Forty-one percent of the prosthetic knees had received antibiotics prior to collection of microbiology samples. Forty-five percent of these had an organism identified. Of the 59% that did not have antibiotics 81% had an organism identified. Overall 67% had an organism isolated, fifty-six percent of these retained their implant. Thirty-three percent of those with no organism identified retained their implant.

Introduction

The results of the mobile bearing Oxford unicompartmental knee replacement (UKR) in the lateral compartment have been disappointing with a five year survival of 82%. Therefore, it is recommended that mobile bearings should not be used for lateral UKR. This low survivorship is primarily due to high dislocation rate, all occurring in the first year. A detailed analysis of the causes of bearing dislocation confirmed the elevated lateral tibial joint line to be a contributory factor. A new surgical technique was therefore introduced in which care was taken neither to remove too much bone from distal femur nor to over tighten the knee and thus ensure that the tibial joint line was not elevated. Other modifications to the technique were also introduced including use of a domed tibial component.

Aim

The aim of this study is to compare the outcome of these iterations: the original series [series I], Series II with improved surgical technique and the domed tibial component [Series III].

INTRODUCTION

Mobile bearing unicompartmental knee replacement (UKR) is an accepted treatment for patients with isolated medial unicompartmental knee osteoarthritis (OA) with a full thickness cartilage loss. The aim of this study was to determine if this recommendation was correct and if the procedure could be used for partial-thickness cartilage loss.

METHODS

1053 Oxford medial UKRs were studied prospectively. The knees were divided into two groups; partial-thickness cartilage loss (PTCL) group and the full thickness-cartilage loss (FTCL) group. The primary outcome measure was the total Oxford Knee Score (OKS, 0 to 48) at the time of final follow up. The groups were also compared for the change in OKS (?OKS) and the proportion of patients that were considered to have benefited substantially from surgery (?OKS >5).

Introduction

Kozinn and Scott have made recommendations about contra-indications for unicompartmental knee replacement (UKR). They suggest that patients younger than 60, weight > 82 kilograms, patients with exposed bone in patella-femoral compartment or patients who are physically active/perform heavy labour should not be offered a UKR. In addition, chondrocalcinosis is a contra-indication. These strict selection criteria are based on the experience with fixed bearing UKAs and are more intuitive than evidence based. The Oxford UKR has a fully congruous mobile bearing and has been shown to have minimal wear. Over the past 25 years, the Oxford Group has followed a standardised protocol for patient selection for UKR. We ignore patella-femoral joint pathology, chondrocalcinosis, patient's age, weight and activity level when deciding the suitability for UKR.

Methods

Using the standardised indications, more than 1100 Oxford UKRs have been performed to date over the last 10 years. These patients are assessed pre-operatively and at regular intervals post-operatively in a dedicated research clinic. We present the results of these consecutive cases. Patients were classified into two groups: group I (satisfy Kozinn-Scott recommendations) and group II (outside recommendations).

Purpose of the study

Assessing medium term outcome of medial Uni compartmental replacement and whether there is a difference in outcome between mobile and fixed bearing variants of the same prosthesis.

Methods

Knee outcome was assessed in 150 patients (81 male, 69 females, mean age 67.0±10.4yrs) undergoing medial UKR knee (Uniglide, Corin Medical, UK) using either fixed or mobile bearing prosthesis between 2002-2007. All operations were performed by members of the Bristol knee group. All patients were scored using the American Knee Score (AKS), Oxford Knee Score (OKS), and WOMAC pre-operatively and at 2-year follow up. The mobile group (n=93) comprised 43 males and 50 females, aged 62.8±8.9yrs. The fixed bearing group (n=57) comprised 38 males and 19 females, aged 74±8.8yrs.

Purpose of Study

To assess the incidence of radiolucency in cemented and cementless Oxford unicompartmental knee replacement at two years.

Introduction

Most unicompartmental knee replacements (UKRs) employ cement for fixation of the prosthetic components. The information in the literature about the relative merits of cemented and cementless UKR is contradictory, with some favouring cementless fixation and others favouring cemented fixation. In addition, there is concern about the radiolucency that frequently develops beneath the tibial component with cemented fixation. The exact cause of the occurrence of radiolucency is unknown but it has been hypothesised that it may suggest suboptimal fixation.

Purpose of study

To investigate the linear penetration rate of the polyethylene bearing in unicompartmental knee arthroplasty at twenty years.

Introduction

The Phase 1 Oxford medial UKR was introduced in 1978 as a design against wear, with a fully congruous articulation. In 1987 the Phase 2 implant was introduced with new instrumentation and changes to the bearing shape. We have previously shown a linear penetration rate (LPR) of 0.02 mm/year at ten years in Phase 2, but that higher penetration rates can be seen with impingement. The aim of this study was to determine the 20 year in-vivo LPR of the Oxford UKR, using Roentgen Stereophotogrammetric Analysis (RSA).

Introduction

Obesity has been considered a relative contra-indication in unicompartmental knee arthroplasty (UKA) due to fear of high wear rates, loosening and tibial collapse. The aim of this study was to investigate the impact of high body mass index (BMI) on ten-year survivorship and five-year functional outcome after Oxford UKA, a fully congruous mobile bearing design with large contact area and low wear rate.

Methods

This prospective study examines a consecutive series of 595 knees (mean age 66 years, range: 33-88) undergoing Oxford UKA with a minimum 5-year follow-up. Patients were divided into three groups; Group I (Normal body weight), BMI <25 (n=171), Group II (overweight), BMI 25- 30 (n=264), and Group III (Obese), BMI ≥30 (n=160). The survivorship and functional outcome (as assessed by change in Oxford Knee Score [DeltaOKS]) and Knee Society Score (KSS) for all three groups were compared.

Introduction

The use of a mobile-bearing knee system is increasing in modern total knee arthroplasty (TKA). Mobile-bearing TKA improves kinematics and is reliable and capable of providing substantial benefit for patients. The aim of this study was to report independent long term results of uncemented low contact stress (LCS) mobile bearing total knee replacement

Methodology

We examined the outcome of 138 consecutive patients who underwent uncemented LCS total knee replacement between 1996 and 2000. Oxford knee score was noted.

Introduction

Unidirectional mobile bearing knees (RP) were developed to optimise the tibio-femoral articulation in an effort to enhance function and reduce polyethylene wear. The self aligning bearing should also benefit the patello-femoral joint further improving outcome. This study was designed to assess whether these potential benefits are realised in the clinical setting.

Methods

A total of 352 patients undergoing a PS PFC Sigma TKR were randomly allocated to receive either a Mobile Bearing (176 knees) or a Fixed Bearing (176 knees) tibial tray. Within each group a further randomisation for patella resurfacing versus retention was included. All knees were scored using standard tools (Oxford, AKSS, Patella Score) by independent nurse specialists.

At 5 year review there had been 38 deaths (19 in each group), 5 revisions (4 fixed, 1 RP), 7 late patella resurfacings (4 fixed, 3 RP) and a small number of other patients had withdrawn, leaving 142 fixed bearing knees and 144 mobile bearing knees for evaluation.

Purpose of Study

To investigate the proprioceptive function of patients with an ACL rupture before and after reconstruction and correlate these findings with ligament laxity testing and clinical outcome measures.

Summary of Methods and Results

Fifty patients with an ACL rupture and 50 normal controls were recruited to the study. The Biodex Balance SD System was used to assess knee proprioception. This equipment measures proprioceptive function using an electronic platform. The balance of the subject is computed using stabilometry and an Overall Stability Index (OSI) is produced. A lower score reflects better proprioception. Knee stability was assessed clinically and with the Rolimeter knee arthrometer in all subjects. Participants were evaluated using the Tegner, Lysholm, Cincinnati and IKDC scoring systems. In the ACL group, 34 patients underwent ACL reconstruction and returned for their follow-up review 3 months post-operatively. The proprioceptive function of the injured knee of the ACL group (mean OSI 0.70) was significantly poorer compared to that of their uninjured knee (mean OSI 0.46, p<0.001, 95%CI 0.14, 0.34) and to the Normal Control group (mean OSI 0.49, p=0.01, 95%CI 0.05, 0.38). There was a significant improvement in proprioception of the injured knee following ACL reconstruction (mean OSI 0.47, p=0.003, 95%CI 0.10, 0.42). A significant correlation was found between pre-operative proprioception measurements and all the pre-operative knee outcome scores, however this correlation was not found post-operatively. No correlation was found between ligament laxity testing and either proprioception measurements or knee outcome scores.

Hypothesis

Recent advances in understanding of ACL insertional anatomy has led to new concepts of anatomical positioning of tunnels for ACL reconstruction. Femoral tunnel position has been defined in terms of the lateral intercondylar ridge and the bifurcate ridge but these can be difficult to identify at surgery. Measurements of the lateral wall either using C-arm x-ray control or specific arthroscopic rulers have also been advocated.

Method

30 patients undergoing ACL reconstruction before and after introduction of a new anatomical technique of ACL reconstruction were evaluated using 3D CT scan imaging with cut away views of the lateral aspect of the femoral notch and the radiological quadrant grid. In the new technique, with the knee at 90 degrees flexion, the femoral tunnel was centred 50% from deep to shallow as seen from the medial portal (Group A). Group B consisted of patients where the femoral tunnel was drilled through the antero-medial portal and offset from the posterior wall using a 5mm jig.

AIM

We aim to identify whether meniscal repair at the time of ACL reconstruction was associated with a better outcome than meniscectomy.

Method

We prospectively collected data on 233 consecutive patients undergoing ACL reconstruction in our unit. A four strand autologous hamstring graft was used with suspensory femoral fixation, and a tibial interference screw. At surgery the presence and location of chondral and meniscal injuries was noted, and whether the meniscal lesion was resected or repaired. Patients were reviewed and scored by a specialist physiotherapist practitioner pre-operatively, and at 6, 12, and 24 months. Tegner, Lysholm, and Cincinatti knee scores were used.

Introduction

Aim of our study was to find an association of additional intra-artricular derangements due to the delay in referring a patient with Anterior Cruciate Ligament (ACL) injury to a consultant orthopaedic clinic.

Methods and results

We carried out a retrospective review of 50 patients who underwent ACL reconstruction (performed arthroscopically taking semitendinosis tendon graft) between July 2007 and November 2008. Orthopaedic referrals were grouped into A&E-group (48%) and GP-group (52%). Average time span between initial injury and patient's first contact with an orthopaedic surgeon was 10 days in the AE-group and 30 months in the GP-group.

On analysing the MRI scans we found a significant difference regarding the presence of additional injuries: A&E-group had less medial meniscus injuries (43.75%) compared to the GP-group (65%). Lateral meniscus injuries were present in 18.75% in A&E-group and in 35% in GP-group. Findings during arthroscopic ACL reconstruction revealed following differences: A&E-group had less medial meniscus injuries (30.43%) compared to the GP-group (46.15%). Lateral meniscus injuries were 43.48 % and 30.77 % in A&E-group and GP-group respectively.

Lysholm Knee Scoring system was used in both the groups pre- and postoperatively. The A&E-group had better results preoperatively (average 56.7) and postoperatively (average 95.5) when compared to the GP group which had shown scores to be 50.4 (pre-op) and 90.7 (post-op).

Aim

To examine the effects of total knee arthroplasty on markers of inflammation and endothelial dysfunction, as surrogate markers for enhanced risk of vascular disease or precipitation of acute vascular events post-operatively.

Methods

All patients undergoing an elective uncemented total knee arthroplasty at a district general hospital were approached at the pre-assessment clinic. The study was explained and the patients were enrolled into the study following written consent.

Venous blood samples were taken pre-operatively, day 1 and day 7 post-operatively. Serum levels of interleukin 6 (IL6), tumour necrosis factor (TNF??, e-selectin, Von willebrand factor (vWF), tissue plasminogen activator (tPA) and soluble CD40 ligand were analysed. Also, real time analysis of the expression of CD40 and CD14/CD42a aggregates on monocytes was carried out using flow cytometry. Patients were excluded from the study if there were signs of either superficial or deep infection.

Introduction

Trochlear dysplasia (TD) is still poorly recognised, generally considered uncommon and to present purely as persistent patella dislocation.

Diagnosis

87 patients diagnosed as having TD by a true lateral X-ray, MRI scan or at surgery were sent a questionnaire about their initial symptoms. 60% had suffered adolescent anterior knee pain. Lack of trust, wobbling, stair problems, giving way and catching were also common symptoms. Only 66% had ever suffered a dislocation, their troubles had started at 12 years of age. Most had undergone unsuccessful realignment procedures and many had developed premature lateral patello-femoral arthritis.

Aim

The aim of this study was to study the course of the infra-patellar branch of the saphenous nerve (IPBSN) and describe its anatomical variations and relations.

Materials and Methods

Twenty-eight formalin-fixed cadaver lower extremity specimens were methodically dissected in the University Department of Anatomy. Dissection included identifying the saphenous nerve and tracing it distally till it pierced the deep fascia between the tendons of gracilis and sartorius. At this point, the saphenous nerve gave a branch that pierced the sartorius and became subcutaneous, known as the infrapatellar branch. The association of the nerve trunk with the sartorius muscle in terms of whether it originated above it, below it or pierced through it was studied. Following this the nerve was dissected along its course distally to the point of its termination where it gave one to three branches. The relationship of the point of termination of the IPBSN with bony surface landmarks like the medial border of the patella, the apex of the patella and the tibial tuberosity were also studied. The distance of the trunk from medial margin of patella was measured.

Introduction

Autologous chondrocyte implantation presents a viable alternative to microfracture in the repair of damaged articular cartilage of the knee; however, outcomes for patellar lesions have been less encouraging. ChondroCelect (CC) is an innovative, advanced cell therapy product consisting of autologous cartilage cells expanded ex vivo through a highly controlled and consistent manufacturing process.

Purpose

To assess the effect of CC in the treatment of patellofemoral lesions, for which standard treatment options had failed and/or no other treatment options were considered feasible.

Purpose

To assess the midterm functional results after Medial Patellofemoral Ligament (MPFL) reconstruction with single semitendinosis autograft in patients with patellofemoral instability.

Methods - Results

Forty six knees (45 patients) with patellofemoral instability were treated with surgical stabilisation of the patella with a single semitendinosis autograft and followed up for a minimum of 24 months. The average follow-up was 33.5 months (range 24-54 months). Clinical evidence of patellar instability and radiological (MRI) evidence of MPFL rupture or deficiency was documented prior to surgery. The average post injury interval was 22.3 months. Ipsilateral joint co-morbidities included previous lateral release or distal realignment (n=10), patellofemoral joint (PFJ) dysplasia (n=14) and concurrent ACL, PCL and/or MCL rupture (n=6). Knee function was assessed preoperatively and postoperatively with the use of Kujala, Tegner, Lysholm and International Knee Documentation Committee (IKDC) scores. There were 34 male and 11 female patients with a mean age of 32.5 years (range 17 - 60 years). All measured knee function scores improved postoperatively. Kujala score improved from 58 to 77 (95%CI +/− 9.71). Tegner score improved from 3 to 5 (95%CI+/− 0.65). IKDC score improved from 51 to 75 (95%CI +/− 5.27) and Lysholm score improved from 59 to 79 (95%CI +/− 6.5).

AIMS

The aim of this study was to assess the knee function after MPFL reconstruction with single hamstring autograft.

METHODS-RESULTS

In this case series 68 patients (69 knees) were treated in total. Clinical and radiological evidence of patellar instability and MPFL rupture or deficiency was documented prior to surgery. The MPFL was reconstructed with semitendinosus autograft. The free end of the graft was rerouted through the most distal part of the medial intermuscular septum proximally to the adductor tubercle, to the superomedial border of the patella, where it was fixed, whereas its distal insertion to the tibia was preserved. Knee function was assessed preoperatively and postoperatively with the use of Kujala, Tegner, Lysholm and International Knee Documentation Committee (IKDC) scores. There were 46 male and 22 female patients with an average age of 25.8 years (median age 23) ranging from 11 to 54 years. The mean follow-up was 19.6 months (range 6-54 months). Ten of the patients had findings of femoral trochlear dysplasia. All knee functional scores significantly improved postoperatively. Kujala score improved from 56 to 84, Tegner score improved from 2 to 6, IKDC score improved from 48 to 75 and Lysholm score improved from 53 to 80. One of the patients required revision of the MPFL reconstruction following traumatic redislocation of the patella.

Aim

To assess the survival of revision knee replacements at our institution and to identify prognostic factors that predict failure in revision knee surgery.

Materials and methods

This was a retrospective review of 52 patients who had undergone revision knee surgery as identified by hospital clinical coding. Patient demographics, physiological parameters, reason for revision, type of revision implant and last date of follow up were recorded from the medical records. Implant survival was analysed both from the index primary procedure to revision and from definitive reconstruction at revision to re-operation for any cause.

Introduction

Rupture of the anterior cruciate ligament (ACL) is a common injury and often presents with a typical injury pattern. Historic literature has shown that the accuracy of diagnosis of ACL ruptures is poor at the initial medical consultation despite the history of injury strongly suggesting an ACL injury. The aims of this study were to determine: if the accuracy of diagnosis of ACL ruptures at initial presentation has improved over the last decade; grade of medical staff at initial and subsequent consultations; the mechanism of injury; and the subsequent delay in diagnosis and definitive treatment.

Materials and Methods

One hundred and thirty two consecutive patients who underwent ACL reconstruction between January 2005 and January 2009 were analysed using prospective collected data. The mean age of the patients was 29 years (12-57). Sixteen patients were excluded due to chronic ACL injury (15).

Background

The cemented mobile bearing metal backed low contact stress patellofemoral arthroplasty (LCS PFA) is a newer design belonging to the second generation of inlay type implant, based on the more successful knee arthroplasty model. The advantage is the patella can articulate with the trochlear implant as well as the femoral component of a total knee replacement (TKR).

Patients

This series is a cohort of 21 patients who underwent 24 (3 bilateral) unicompartmental PFA replacements for isolated patellofemoral osteoarthritis. We have used the mobile bearing LCS PFA in all of them. There were 3 males and 18 females. Average age was 51(40-58) years. The Oxford Knee score was used to assess the results.

Aims

The study was designed to gauge adequacy of pain relief in the first 5 days following TKA, in particular comparing the Painbuster device (B Braun, Sheffield, UK) with more routine modalities.

Methods

In a prospective, multi-disciplinary audit, all post-operative in-patients completed a pain diary. Pain was recorded as none (0), mild (1), moderate (2) or severe (3), three times a day. This information was collated, along with the pre-operative Oxford knee score, type of anaesthetic, and use of post-operative analgesia. This included oral and intravenous medication, local anaesthetic infiltration and the Painbuster, a continuous infusion device which delivers bupivacaine into the knee for 48 hours.

Hypothesis

Avascular meniscal tears can be repaired with good clinical outcomes.

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.

Summary

We report a large study of 331 patients at two years post operation who were prospectively randomised to receive either a rotating platform or a fixed bearing knee replacement of an otherwise identical design.

Introduction

The mobile bearing total knee replacement was developed as there are theoretical benefits in that it may allow a better range of motion, better patella tracking and lower wear rates. This study was designed to see if these potential advantages are borne out in practice when using a cruciate retaining design.

Purpose

To study the initial presentation and subsequent investigation and management of acute knee dislocations at a regional trauma centre.

Introduction

Knee dislocation requires high energy trauma, and often affects young working adults. The high incidence of associated arterial, neurological, ligamentous, and other soft tissue injuries, can produce potentially devastating outcomes. Rapid mobilisation of traditionally distinct surgical teams, with urgent vascular imaging and emergency surgery are often necessary. The extent and severity of ligamentous damage may require multiple operations to repair.

Introduction

The aim of this study was to compare the outcome between the first and second knee replacement in patients undergoing staged bilateral total knee arthroplasty.

Methods

A prospective database of outcomes of knee replacements performed at Broadgreen Hospital was commenced in 2003. Data is collected pre operatively, 3 and 12 months post operatively and every two years thereafter. We identified 64 patients (26 male, 38 female) who had bilateral knee replacements and had at least one year post operative outcome studies. Data on pain scores, walking ability (score 1-6), use of walking aids (score 1-6), range of movement, instability, muscle strength, WOMAC scores, SF-12 scores, the Knee Society Radiological Score and length of hospital stay were identified. We compared data between the first and second knee operation.

Introduction

The aim of this study was to investigate whether methylene blue dye, commonly used in sterile surgical marker pens, would have an effect on human chondrocyte viability, when cultured on a collagen membrane in-vitro.

Methods

Bilayered collagen membranes were seeded in duplicate with 12 million human chondrocytes per ml and cultured for 24 hours under standard conditions. Group A consisted of a membrane marked with methylene blue ink on its smooth side, group B marked on its porous side, and group C acting as an unmarked control. At the end of the culture period the membranes were qualitatively analysed for cell survival by live/dead fluorescent staining under confocal microscopy.

Introduction

The purpose of this study was to investigate whether combining PRP or concentrated bone marrow aspirate (CBMA) with a biphasic collagen/glycosaminoglycan (CG) scaffold would improve the outcome of the treatment of full thickness osteochondral defects in sheep.

Materials and Methods

Osteochondral defects (5.8×6mm) were created in the medial femoral condyle (MFC) and the lateral trochlea sulcus (LTS) of the stifle joints of 24 sheep. Defects were either left empty or filled with a 6×6mm CG scaffold, either on its own or in combination with PRP or CBMA (n=6). At 6 months the sheep were euthanised, and the repair tissue subjected to mechanical testing, gross morphological analysis, semi quantitative histological scoring and immunohistochemical staining including types I, II and VI collagen.

Introduction

The Rapid Recovery Program (RRP) is a holistic perioperative accelerated discharge process that aims to improve efficiency and quality of care, improve patient education, standardise protocols and pathways and encourage early mobilisation & discharge.

Aims

To compare length of stay (LOS) of primary knee arthroplasty patients before and after implementation of the RRP.

Introduction

This study investigates and compares the accuracy of pre-operative templating from the AP and lateral radiographs in total knee arthroplasty.

Methods

Pre-operative radiographs from 478 patients undergoing primary total knee arthroplasty from September 2006 to April 2009 were reviewed. 154 had digital templating performed on both the AP and lateral radiograph The sizes templated for both the femoral and tibial components were recorded from the PACS archive. These were compared aginst the implanted femoral and tibial sizes taken from the theatre record.

A Z-score for two proportions was used to determine the level of significance of any difference in accuracy between the AP and lateral views for each component.

Introduction

Unicondylar knee replacements (UKR) may be more effective compared to Total knee replacements (TKR) in unicompartmental arthritis. We report patient outcomes & satisfaction data in an age matched cohort of patients with either a UKR or TKR.

Method

A single unit and single surgeon series of patients were recruited. Data was retrospectively collated for 68 patients with more than 24 months follow-up. UKR was undertaken in patients with isolated medial compartment osteoarthritis; stable ACL and less than grade 3 lateral patellar changes of the Outerbridge classification. TKR was undertaken for the rest. The patients were assessed with validated knee scores including the Total Knee Function Questionnaire (TKFQ) which focuses on recreational & sporting outcomes as well as activities of daily living (ADL). Patient satisfaction and perception of knee normality was measured on a visual analogue scale.

Purpose of the study

We report the problems associated with setting up an electronic arthroplasty surveillance plan and suggest some solutions which are appropriate to the modern NHS setting.

Methods and Results

In 2006, the lower limb arthroplasty surgeons at UHCW NHS Trust decided to set up a ‘virtual’ arthroplasty surveillance plan to provide long-term radiographic and patient reported clinical outcomes for all patients undergoing hip and knee arthroplasty. In the face of increasing pressure upon outpatient waiting time and funding issues, this system was designed to replace the routine clinical review of patients in the outpatient department.

While simple in principle, the virtual arthroplasty surveillance plan required input from surgeons and allied health professionals, hospital management, PCT clinicians, PCT finance, hospital finance, IT services and of course patients. However, in 2009 we were able to provide an electronic record of functional outcome scores and associated radiographs for over 1000 patients who had primary hip and knee arthroplasty surgery in our unit. Response rates for the first 6 months of 2009 for hip arthroplasty were 85.2% for functional outcomes and 84.2% for radiographic review. The subsequent clinical input is managed through ‘virtual’ clinics which provide a means to track patient outcomes and also an automated mechanism for financing the system. There are several areas which can still be improved, but early qualitative feedback suggests that this system provides high levels of satisfaction for both patients and surgeons.

Introduction

Differing descriptions of patellar motion relative to the femur have resulted from many in-vitro and in-vivo studies. The aim of this study was to examine the tracking behaviour of the patella. We hypothesized that patellar kinematics would correlate to the trochlear geometry.

Method

Seven normal fresh-frozen knees were CT scanned and their kinematics with quadriceps loading was measured by an optical tracker system and calculated in relation to the previously-established femoral axes. CT scans were used to reliably define frames of reference for the femur, tibia and the patella. A novel trochlear axis was defined, between the centres of best-fit medial and lateral trochlear articular surfaces spheres.

Introduction

The trochlear groove plays a major role in the mechanics and patho-mechanics of the patellofemoral joint. Our primary goal was to compare normal, osteoarthritic and dysplastic PFJs in terms of angles and distances.

Method

Computed tomography scans of 40 normal knees (>55 years old), 9 knees with patellofemoral osteoarthritis (group A) and 12 knees with trochlear dysplasia (group B) were analysed using 3D software. The femurs were orientated using a robust frame of reference. A circle was fitted to the trochlear groove. The novel trochlear axis was defined as a line joining the centres of two spheres fitted to the trochlear surfaces, lateral and medial to the trochlear groove. The relationship between the femoral trochlea and the tibiofemoral joint was measured in term of angles and distances (offsets).T-test for paired samples was used (p<0.05).

Introduction

Tibial patho-morphology has been described as a factor that predisposes to medial compartment osteoarthritis of the knee in 2D analysis. The aim of this study was to investigate whether the morphology of normal and pre-OA medial compartments are really different in 3 dimensions.

Method

A total of 20 normal (group A) and 20 pre-OA knees (group B) were included. Group A consisted of contra-lateral knees of young patients awaiting hip surgery and group B of asymptomatic contra-lateral knees of patients awaiting unicompartmental knee arthroplasty (UKA).

Using 3D reconstructions from CT scans, femurs were aligned to the transcondylar and anatomical axes. The medial femoral extension facet was modelled as a sphere. Its radius and the offsets between its centre and the medial flexion facet centre were measured. The tibias were aligned to a flat portion of the flexion facet (flexion facet plane. A model of analysis was developed by rotating several increments towards and away from the midline to obtain several sagittal section images. For each sagittal section the extension facet angle (EFA), its length, and the submeniscal plane angle and length were analysed.

Introduction

SPECT/CT might be a promising diagnostic modality in patients with painful total knee arthroplasty. It was the purpose of our study to introduce a novel standardised SPECT/CT algorithm for assessing patients with painful primary total knee arthroplasty and to evaluate its clinical applicability and inter- and intra-observer variation and reliability.

Methods

A novel SPECT/CT localisation scheme, which consists of 9 tibial, 9 femoral and 4 patellar regions on standardised transverse, coronal, and sagittal slices was introduced. It was assessed in 18 consecutive patients with painful knees after total knee arthroplasty. The localisation and level of the tracer uptake on SPECT/CT were noted using a color coded 10 steps graded scale (0-100). The inter and intra-observer reliability were assessed. The femoral and tibial prosthetic component position was assessed in the CT images after 3D reconstruction and aligning them to standardised frames of reference. The average root mean square difference±standard deviations and ranges of these measured angles are presented along with the intraclass correlation coefficients for inter- and intraobserver reliability.

Aim

A case series with functional and radiographic outcomes, of modular endoprosthetic distal femoral replacement in complex cases of periprosthetic fracture.

Method

Sixteen cases were identified of endoprosthetic replacement (EPR) from the bone and soft tissue cancer implant registry. A retrospective review was undertaken.

Purpose of Study

1- To introduce a new graft technique for ACL reconstruction using the patellar tendon with its attachment on the tibial tuberosity as bone-tendon (B PT) auto graft sparing the patella.

2-To assess the above described technique prospectively in a group of patients with ACL deficient knees.

Type of study

Prospective case series of a newly describedACL graft technique.

INTRODUCTION

Bone marrow derived mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in adult stem cells. In this study we characterised bone marrow derived stem cells and investigated the effects of hypoxia on gene expression changes and chondrogenesis.

MATERIALS AND METHODS

Adherent colony forming cells were isolated and cultured from the stromal component of bone marrow. The cells at passage 2 were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions for 14 days. Gene expression analysis, glycosoaminoglycan and DNA assays, and immunohistochemical staining were determined to assess chondrogenesis.

Introduction

Mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. We have previously demonstrated that the infrapatellar synovial fat pad is a rich source of mesenchymal stem cells and these cells are able to undergo chondrogenic differentiation. Although synovial fat pad derived mesenchymal stem cells may represent a heterogenous population, clonal populations derived from the synovial fat pad have not previously been studied.

Materials and Methods

Mesenchymal stem cells were isolated from the infrapatellar synovial fat pad of a patient undergoing total knee arthroplasty and expanded in culture. Six clonal populations were also isolated before initial plating using limiting dilution and expanded. The cells from the mixed parent population and the derived clonal populations were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium for 14 days. Gene expression analyses; glycosoaminoglycan and DNA assays; and immunohistochemical staining were determined to assess chondrogenic responses.

Introduction

Tranexamic acid (TXA) reduces total knee replacement (TKR) & total hip replacement (THR) blood loss. We launched a ‘fast track’ protocol to reduce inpatient stay including a single 15mg/kg dose of TXA. We conducted a retrospective cohort analysis on haemoglobin balance and transfusion requirement before and after the protocol, which aimed to reduce blood loss during lower limb arthroplasty.

Methods

Patients undergoing primary cemented THR or TKR were drawn from the periods: control 1/10/06 to 31/3/07; fast track 1/4/08 -31/7/08. We identified pre- and post-operative Day 1 haemoglobin concentration (Hb g/dl), and transfusion number & timing. Transfusion trigger was Hb<8 unless symptomatic. In patients transfused before the Day 1 assay, we corrected Hb drop for number of units given, (1 unit ≍ 1g/dl). Outcome measures are Day 1 Hb drop corrected for transfusion (t-test) and number transfused (Chi-squared).

Statement of purpose

To analyse the distribution of osteoarthritis of the knee, to determine what proportion of patients may be suitable for a partial knee replacement and finally to assess the risk of wear progression.

Summary of methods used and results

The intra-operative articular surface mappings were collected for 250 consecutive patients undergoing knee arthroscopy. Patients were graded using the Outerbridge Classification. Radiographs including antero-posterior standing, postero-anterior flexion (Rosenberg), lateral and skyline views were graded (Kellgren and Lawrence) and compared with the arthroscopic findings.

13.3% of knees showed ‘isolated’ medial disease of Outerbridge Grade 3 or worse. Isolated lateral disease was noted in 1.4%, patello-femoral disease in 24.3%, bi-compartmental (Medial/PFJ) disease in 30.9% with tibio-femoral and tri-compartmental disease in 15.2%. The combination of lateral and patello-femoral disease was seen in 14.8%.

The mean age of patients with tri-compartmental disease (60.9 years) was greater than the mean age of those suffering with osteoarthritis limited to one or two compartments (54 years)

Radiological analysis revealed AP views had only 66% sensitivity and 73% specificity for the presence of Grade 3/4 lesions in the medial compartment. Rosenberg views had 73% sensitivity and 83% specificity. Skyline views had a sensitivity of 56% and 100% specificity.

Purpose of Study

To identify the early functional outcomes, survivorship and complications associated with the Corin Uniglide Unicompartmental Knee Replacement (UKRs) from an independent centre.

Methods and Results

A prospective consecutive case series of sixty Uniglide UKRs was carried out in fifty-one patients between January 2006 and March 2009. The data collected included:

Primary outcome measures:

Pre- and post-operative American Knee Society Score (AKSS), Oxford Knee Scores (OKS), WOMAC

No cases were lost to follow-up. Mean follow-up time was 19 months (12 to 36months) and mean age was 66 years (39 to 78 years).

Kaplan-Meier Survivorship showed 95% survival at 3 years (CI:6.4).

All functional outcomes showed significant improvement p <0.05. There were two revisions within the first year, which were the main complications, secondary to aseptic tibial loosening and collapse of the posteromedial tibia. The x-ray error score identified the most common error as the femoral flexion/extension angle followed by the anterior/posterior fit.

Purpose

To evaluate the normal bony profiles of the anterior surface of the distal femoral cortex, its relation to the posterior condylar plane and assess the implications of these findings to anterior femoral referencing.

Methods and Results

Fifty well preserved adult, cadaveric femora were studied. Different points on the proximal and distal femur were recorded using an optoelectronic system based around a commercial navigation system. Definitions were: anterior femoral plane (AFP) derived from nine points on the anterior cortex of the distal femur; posterior condylar plane (PCP) as the plane parallel to the sagittal mechanical axis of the femur and containing the PCA. The anterior femoral cortex was divided into lateral, median and medial areas. Average heights of each of these areas from the PCP were calculated, as were the angles between the PCP and AFP.

Four distinct anterior cortex profiles were seen. In 28 specimens the lateral side had the highest mean height and the medial side had the lowest mean height (Group 1). For 13 specimens the lowest mean height was in the median area (Group 2) but 7 specimens had highest mean height here (Group 3). Only 2 specimens had the highest mean height on the medial side with the lowest mean height on the lateral side (Group 4). The average angle between the AFP and the PCP was 1.3° of external rotation. In Group 1 the AFP angle was more internally rotated (-10° to -2°) compared to the other groups, in particular Group 4 which showed the most external rotation (3° and 4°).

Objective

To investigate the reasons for revision of Oxford Unicondylar Knee Replacement (UKR). Does insert size used relate to requirement for revision?

Methods

We retrospectively reviewed the cases needing revision from a single surgeon consecutive series of 209 ‘Oxford’ UKRs. 10 cases required early (within 2 years) revision. The reasons for revision were investigated. A comparison of cases requiring revision by insert size implanted was made.

Aim

The aim of our study was to assess lateral tracking of the patella with differing designs of Total Knee Arthroplasty (TKA) and compare to that of the native patella.

Method

A modified caliper was used to measure the width and position of the patella relative to the femur at different degrees of knee flexion. The relationship of the patella midpoint to that of the femur was subsequently assessed. Group 1 consisted of 25 native knees. Group 2 consisted of 25 patients with antero-posterior stabilised knee implant with a spherical medial condyle and a deep lateralised patellar groove, and Group 3 consisted of 25 patients with a conventional cam-and-post design with a midline patellar groove. The mean follow-up was 28 months.

Introduction

There are numerous surgical techniques for medial patellofemoral ligament (MPFL) reconstruction. Problems with certain techniques include patellar fracture and re-rupture.

Aim

To investigate the functional outcomes of MPFL reconstructions performed using a free gracillis tendon graft, oblique medial patella tunnel and interference screw femoral fixation. Patients were selected for MPFL reconstruction if they had recurrent patellar dislocations, and with the use of clinical and radiographic evaluation.

Introduction

Current problem – Multiple surgical interventions for patellar instability and no defined criteria for use of medial patellofemoral ligament (MPFL) reconstruction.

Aims

Investigate the functional outcomes of MPFL reconstructions that had been performed following selection for treatment based on a defined patellar instability algorithm.

Purpose of the study

To compare the patellofemoral kinematics and patella stability of a new TKR, with a continuous radius versus an established J shaped knee system and the natural knee. It was hypothesised that the high performance new TKR would be a better match to the natural knee and anatomical patella tracking would provide a more stable patella.

Methods

A cadaveric study using physiological loads examined the continuous kinematic behaviour (optical tracking system) of the tibiofemoral and patellofemoral compartments in 6 knees for the native, kinemax and new design triathlon knee systems.

Objectives

To investigate the value of tranexamic acid (TA) in reducing blood loss and blood transfusion after TKR and other clinical outcomes such as deep venous thrombosis (DVT), pulmonary embolism (PE), ischaemic heart diseases and mortality.

Methods

A systematic review and meta-analysis of published randomised and quasi-randomised trials which used TA to reduce blood loss in knee arthroplasty was conducted. The data was evaluated using the generic evaluation tool designed by the Cochrane Bone, Joint and Muscle Trauma Group.

Purpose

To determine the effect that Titanium Nitride (TiN) coatings have on wear rates of ultra high molecular weight polyethylene (UHMWPE)

Background

Ceramic coatings have been shown to confer advantageous countersurface scratch resistance in knee arthroplasty. This may reduce UHMWPE wear rates and revision rates. Dermal hypersensitivity is a common problem with metals; TiN, a ceramic surface, has been used to prevent it. There is little data in the literature regarding the effect of TiN on UHMWPE.