The aim of this study was to analyze and compare clinical, radiological and mortality outcomes of patients who underwent cemented hip hemiarthroplasty for displaced neck of femur fractures using a SPAIRE technique when compared to a pair-matched control cohort who underwent the same procedure using the direct lateral approach.

A retrospective review of patients who underwent cemented hip hemiarthroplasty for displaced neck of femur fractures by a single surgeon using a SPAIRE technique over a two-year period between July 2019 and July 2021 was performed. These were subsequently pair matched in a 5:1 ratio for age, gender, ASA grade and residential status with a control group who underwent cemented hip hemiarthroplasty by 4 other surgeons using a direct lateral approach

The study included a total of 240 patients (40 and 200 pairmatched to SPAIRE and control groups respectively), with a mean age of 81.0 ± 8.2 years (63–99) and a mean follow-up of 12 ± 3 months (3–30). Overall, there was no significant difference in any of the radiological or mortality outcome scores assessed between the SPAIRE and control groups (p > 0.05 for all). There was a significantly lower number of patients in the SPAIRE group who dropped a level of mobility from their pre-injury baseline at 30-days post-operatively (8.1% versus 31.6%; p = 0.003). However, this appeared to have resolved at 120-day follow-up with no significant differences between the groups in terms of those acquiring a new baseline mobility at 120-days post-operatively (2.7% versus 13.2%, p = 0.09).

In cases of cemented hip hemiarthroplasty for displaced intracapsular neck of femur fractures, the SPAIRE technique appears to offer patients an earlier return to levels of baseline pre-injury mobility when compared to a direct lateral approach.

Hip resurfacing may be a useful surgical procedure when patient selection is correct and only implants with superior performance are used. In order to establish a body of evidence in relation to hip resurfacing, pseudotumour formation and its genetic predisposition, we performed a case-control study investigating the role of HLA genotype in the development of pseudotumour around MoM hip resurfacings.

All metal-on-metal (MoM) hip resurfacings performed in the history of the institution were assessed. A total of 392 hip resurfacings were performed by 12 surgeons between February 1st 2005 and October 31st 2007. In all cases, pseudotumour was confirmed in the preoperative setting on Metal Artefact Reduction Sequencing (MARS) MRI. Controls were matched by implant (ASR or BHR) and absence of pseudotumour was confirmed on MRI. Blood samples from all cases and controls underwent genetic analysis using Next Generation Sequencing (NGS) assessing for the following alleles of 11 HLA loci (A, B, C, DRB1, DRB3/4/5, DQA1, DQB1, DPB1, DPA1). Statistical significance was determined using a Fisher's exact test or Chi-Squared test given the small sample size to quantify the clinical association between HLA genotype and the need for revision surgery due to pseudotumour.

Both groups were matched for implant type (55% ASR, 45% BHR in both the case and control groups). According to the ALVAL histological classification described by Kurmis et al., the majority of cases (63%, n=10) were found to have group 2 histological findings. Four cases (25%) had group 3 histological findings and 2 (12%) patients had group 4 findings. Of the 11 HLA loci analysed, 2 were significantly associated with a higher risk of pseudotumour formation (DQB1*05:03:01 and DRB1*14:54:01) and 4 were noted to be protective against pseudotumour formation (DQA1*03:01:01, DRB1*04:04:01, C*01:02:01, B*27:05:02).

These findings further develop the knowledge base around specific HLA genotypes and their role in the development of pseudotumour formation in MoM hip resurfacing. Specifically, the two alleles at higher risk of pseudotumour formation (DQB1*05:03:01 and DRB1*14:54:01) in MoM hip resurfacing should be noted, particularly as patient-specific genotype-dependent surgical treatments continue to develop in the future.

Introduction and Objective

Ceramic on Ceramic bearings in Total Hip Arthroplasty (THA) afford a low friction coefficient, low wear rates and extreme hardness. Significant complications include hip squeak, ceramic fracture and poor polyethylene performance in revision procedures due to imbedding of abrasive microscopic ceramic fragments. We report on the results of this bearing at a minimum of 10 years.

Aims

The Exeter V40 cemented femoral stem was first introduced in 2000. The largest single-centre analysis of this implant to date was published in 2018 by Westerman et al. Excellent results were reported at a minimum of ten years for the first 540 cases performed at the designer centre in the Exeter NHS Trust, with stem survivorship of 96.8%. The aim of this current study is to report long-term outcomes and survivorship for the Exeter V40 stem in a non-designer centre.

Aims

Europe has found itself at the epicentre of the COVID-19 pandemic. Naturally, this has placed added strain onto healthcare systems internationally. It was feared that the impact of the COVID-19 pandemic could overrun the Irish healthcare system. As such, the Irish government opted to introduce a national lockdown on the 27 March 2020 in an attempt to stem the flow of admissions to hospitals. Similar lockdowns in the UK and New Zealand have resulted in reduced emergency department presentations and trauma admissions. The aim of this study is to assess the effect of the national lockdown on trauma presentations to a model-3 hospital in Dublin, Ireland.

This was a retrospective study of registry data from a National Orthopaedic Hospital for all THRs with 10-year follow-up data. Inclusion criteria were all THRs with a minimum of 10-year follow-up data. All metal-on-metal (MoM) THRs and MoM resurfacings were excluded from the analysis due to the high rate of revision associated with these bearings. Univariate and multivariate analyses controlling for confounding variables were performed to compare outcomes. A total of 1,697 THRs were performed in 1,553 patients. The four significant predictors for revision were fixation type (p<0.01), surface bearing type (p<0.01), age (P<0.05) and head size (p<0.05). Gender, BMI and approach had no effect on revision rates. The lowest 10-year all-cause revision rates were seen in cemented THRs at 1.7%. Ceramic-on-poly bearings had the lowest revision rate at only 1.2%. Metal-on-poly bearings had a 1.7% revision rate. Ceramic on ceramic bearings had a 7.1% revision rate with 1 revision for squeak and 1 revision for ceramic head fracture. The causes for revision in order of decreasing frequency were as follows: Infection (n=13, 0.7%), dislocation (n=7, 0.4%), periprosthetic fracture (n=3, 0.2%) and aseptic loosening (n=2, 0.1%). There were 2 re-revisions at 10 years in total. The smaller 22.225mm head sizes had a significantly lower revision rate than other head sizes (p<0.05). Ceramic-on-poly bearings, cemented fixation and smaller head sizes perform better in the experience of this registry. However, with multivariate analysis, these differences were shown to be insignificant.

Introduction

The emergence of a new variant of subtrochanteric stress fractures of the femur affecting patients on oral bisphosphonate therapy has only recently been described. This fracture is often preceded by pain and distinctive radiographic changes, and associated with a characteristic fracture pattern. We undertook a review of this cohort of patients in our service.

Background and purpose

The two most common complications of femoral impaction bone grafting are femoral fracture and massive implant subsidence. We investigated fracture forces and implant subsidence rates in embalmed human femurs undergoing impaction grafting. The study consisted of two arms, the first examining the force at which femoral fracture occurs in the embalmed human femur, and the second examining whether significant graft implant/subsidence occurs following impaction at a set force at two different impaction frequencies.

Aims

Hip fractures pose a significant burden on the healthcare system. Hyperglycaemia and a state of Type 2 diabetes exists post operatively. Being normoglycaemic has well documented benefits. Pre operative carbohydrate loading has been shown to have two good effects. It decrease hyperglycaemia post operatively and allows the patient to undergo less strict fasting protocols. Insulin resistance to date has not been examined in these patients and this was determined using a validated formula (HOMA/IR).

Introduction

Surgical experience has been shown to improve the clinical outcomes in Total hip arthroplasty. The objective of this study was to compare clinical and radiological outcomes between Consultants and NCHDs grade surgeons for the Exeter total hip replacement taken from the Cappagh National Orthopaedic Hospital Joint Register.

Introduction

A comprehensive met-analysis of anterior knee pain post intramedullary nailing of the tibia was performed by Katsoulis et al in 2006. The principle findings were that 47.4% of patients had anterior knee pain at 2 years post tibial nailing. Worse results were found following a patella tendon splitting approach when compared with a medial para-patellar tendon approach. These conclusions were drawn from 20 studies including 1460 patients.

Currently both approaches to the proximal tibia for nailing are used at JCMH Blanchardstown. A retrospective study was performed to compare the results of tendon splitting and tendon sparing approaches to tibial nails and to compare the results of JCMH with those stated in literature.

Conservative management remains the gold standard for many fractures of the humeral diaphysis with union rates of over 90% often quoted. Success with closed management however is not universal.

Introduction

The incidence of osteochondral lesions following ankle fractures varies in the literature between 17-70%. They are commonly associated with chronic pain and swelling in patients diagnosed with such pathology. There is less evidence about the relationship between OCL and the development of post-traumatic osteoarthritis, the most common type of ankle arthritis.

Summary

A laboratory based study investigating fracture forces and implant subsidence rates in embalmed human femurs undergoing impaction grafting.

The process of femoral impaction grafting requires vigorous impaction to obtain adequate stability but the force of impaction has not been determined. This process has been reported to result in femoral fractures with rates reaching 16%. The aims of this study were to determine the threshold force required for femoral impaction grafting, to determine the affect cortical thickness, canal diameter and bone mineral density (BMD) have on this threshold force and to measure subsidence of an Exeter prosthesis following impaction at the threshold force.

Adult sow femurs were prepared and placed through a DEXA scanner and the BMD and canal diameter measured. Thirty five femurs were impacted with morsellised bone chips and an increasing force of 0.5kN was applied until the femur fractured. Using callipers the cortical thickness of the bone was measured along the fracture line. Once the threshold force was determined 5 femurs were impacted to this threshold force and an Exeter stem was cemented into the neomedullary canal and a 28mm Exeter head attached. Axial cyclic loading was performed between 440N (swing phase of gait) and 1320N (stance phase of gait) for 150,000 cycles at a frequency of 3Hz. The position sensor of the hydraulic testing machine measured the subsidence.

29 tests were successfully completed. The threshold force was found to be 4kN. There was no significant correlation between the load at fracture and the cortex: canal ratio or the bone mineral density. Following impaction with the maximum force of 4kN the average subsidence for the 5 femurs was 0.276mm (range 0.235 – 0.325mm). In this animal study the threshold force was 4kN. Minimal axial subsidence of the implant occurred when impacting the graft with this threshold force. We therefore achieved a stable construct without fracture which is the ultimate goal for the revision hip surgeon.

Introduction: K wiring is a popular technique to help maintain anatomic reduction of distal radial fractures. It has the advantage of being a semi-closed procedure, which is simple to perform. Complications related to K wires include infection, migration and damage to tendons and nerves.

We aimed to perform a randomized prospective study to determine the outcome of Buried versus Exposed K wire placement.

Methods: We prospectively recruited 60 consecutive patients with displaced distal radius fractures requiring K wiring to our study. They were randomized to Buried versus Exposed K wire groups.

Patient details were collected and follow up was performed at 2 and 6 weeks post op.

Infection at pin sites was measured on a 0 to 6 point scale. Superficial radial nerve was assessed with light touch and 2 point discrimination. EPL tendon was also assessed for damage.

Results: 60 consecutive patients were recruited to the study and randomized to buried or exposed k wires. There were 30 patients in each group.

No damage to EPL tendon was recorded in either group at 6/52 follow up.

There was a slight increased rate of superficial infection at exposed pin sites noted at 2/52 follow up however this was not seen at the 6/52 follow up. Superficial radial nerve damage was noted in one case only. This was in the buried k wire group and occurred following removal of the radial wire.

Conclusion: There appears to be slight increased risk of superficial pin site infection in the exposed k wire group at 2/52 but this is not seen at 6/52 follow up. Buried k wires require a second procedure to remove the wires and this runs the risk of superficial radial nerve damage.

The main mode of failure of the acetabular component in total hip arthroplasty is aseptic loosening. Successive generations of cementation techniques have evolved to alleviate this problem.

This paper evaluates one such method, Negative Pressure Intrusion cementation. Two groups of machined bovine cancellous bone samples were created; experimental (n = 26) and control (n = 26). The experimental group was cemented using the negative pressure technique and control group was cemented in the absence of negative pressure. The relative cement intrusion depths were then assessed for each group using MicroCT. These samples were then further machined and tested to failure in torsion to estimate their mechanical properties.

Results show mean cement intrusion depth for the negative pressure group to be 8676μm and 6042 μm for the control group (p = 0.078). Mechanical testing also revealed a greater mean torque in the negative pressure group (1.6223Nm vs 1.2063Nm) (p = 0.095).

This work quantifies the effect of negative intra-osseous pressure on cement intrusion depth in cancellous bone and for the first time relates this to increased mechanical strength.

Aim: It is widely accepted that surgical skills improve with experience. Part of this experience comes from operating on patients while honing new skills. Total hip arthroplasty is one such procedure. This paper examines outcomes in relation to the primary surgeon

Methodology: All patients who had an Exeter femoral component implanted and 2 years follow-up in the hospital joint register had their X-Ray, outcome scores and complications reviewed. Complications are routinely recorded as part of the joint register and hospital computer discharge system. Radiological outcome measures were taken as recommended by Johnston et al. Procedures were recorded as either performed by consultant surgeon or registrar supervised by consultant surgeon.

Results: Post operative WOMAC scores at six months and 2 years were similar in both groups (Consultant 19.6, registrar 22.32 at 6 months) SF-36 figures were similar at six months (Consultant performed 78.56, consultant supervised 75.39). There was a difference in SF-36 at 2 years (72.77 vs 63.11) but this was not statistically significant. Average abduction angle was lower in consultant supervised than consultant performed procedure. (36.75 vs 47 deg) Barrack cement grading was similar in both groups. Consultant inserted stems were more likely to be in neutral position compared to consultant supervised stems (84% vs 56%)

Conclusion: In both goups the quality of life indexes do show a difference in outcome which relates to the primary surgeon.. However decreased abduction angle may lead to decreased range of motion post operatively and should be addressed intraoperatively.

Introduction: K wiring is a popular technique to help maintain anatomic reduction of distal radial fractures. It has the advantage of being a semi-closed procedure, which is simple to perform. Complications related to K wires include infection, migration and damage to tendons and nerves.

We aimed to perform a randomized prospective study to determine the outcome of Buried versus Exposed K wire placement.

Methods: We prospectively recruited 60 consecutive patients with displaced distal radius fractures requiring K wiring to our study. They were randomized to Buried versus Exposed K wire groups.

Patient details were collected and follow up was performed at 2 and 6 weeks post op.

Infection at pin sites was measured on a 0 to 6 point scale. Superficial radial nerve was assessed with light touch and 2 point discrimination. EPL tendon was also assessed for damage.

Results: 60 consecutive patients were recruited to the study and randomized to buried or exposed k wires. There were 30 patients in each group.

No damage to EPL tendon was recorded in either group at 6/52 follow up.

There was a slight increased rate of superficial infection at exposed pin sites noted at 2/52 follow up however this was not seen at the 6/52 follow up. Superficial radial nerve damage was noted in one case only. This was in the buried k wire group and occurred following removal of the radial wire.

Conclusion: There appears to be slight increased risk of superficial pin site infection in the exposed k wire group at 2/52 but this is not seen at 6/52 follow up. Buried k wires require a second procedure to remove the wires and this runs the risk of superficial radial nerve damage.

Thus it would appear that leaving k wires exposed is the safer and more convenient method of K wiring the displaced distal radius fracture.

Introduction: Despite the documented benefits, some countries have yet to agree on the establishment of a national arthroplasty registry.

Aim: The objective of this study was to determine the opinions regarding the establishment of an Irish National register from the Consultant Orthopaedic Surgeons and Senior Orthopaedic trainees in Ireland. We also aim to find the possible reasons why a national joint register has not been established in Ireland.

Method: We have undertaken a questionnaire study to sample the opinions of the Consultant orthopaedic surgeons and Specialist registrars(SR), regarding establishment of an Irish national joint register. The questions asked related to opinions about the setting up, purpose and maintenance of an Irish National Joint Register.

Results: A total of 79 responses were received of 114 questionnaires distributed (a 69% first response rate). 97% believe it is time we set up a registry, 94% will contribute and 81% say it should be made compulsory for unwilling Surgeons and Hospitals to participate. 82% of respondents felt the set up cost should be borne by the government (Health Service Executive). Only10% of consultants agreed that the IOA should be involved in the cost bearing. Despite the overwhelming support for a national register, privacy and liability issues were major concern. 58% of the total respondents strongly agree/agree that access to registry report by the general public can expose surgeons and Hospitals to a medicolegal loophole; hence access to database should be restricted. 78% strongly agree/agree that the registry data may be used as benchmarking tools by the administrators of health-care systems to discriminate methods, implants, surgeons and hospitals, which are found to be underperforming.

Conclusion: There are considerable logistical challenges involved in the establishment of any registry. Other countries have done it successfully, and the benefits are well documented. This subject has endorsement from the Professionals as demonstrated by this study. In a litigious society such as ours, legislation may be required to further protect the integrity of a national joint replacement registry to ensure that the data are used as intended—to serve as an early warning system for premature device failure and to improve outcomes for our patients.

In a prospective randomized trial, we divided a group of patients with a clinically suspicious, although radiographically normal, acute fracture of the scaphoid into 2 groups, 1 treated with a cast (group I), the other with a splint (group II). There were 14 patients in group I, and 18 in group II. Patients were reviewed at 2,6, and 12 weeks for range of movement, grip strength, pain and satisfaction rating. Work disability costs were also calculated for both groups. Patients in group II had better range of movement and grip strength at 2 weeks, although complained of more pain. There was no difference in range of movement, grip strength, or pain at 6 or 12 weeks. Group II was more satisfied at 2 weeks, although not at 6 or 12 weeks. Group I required more time off work, and disability costs were significantly higher [€15,209 per person compared to €3,317 per person]. We recommend that all patients, with only a clinical suspicion of a fractured scaphoid, should have a short period of splint immobilization until symptoms resolve, or until further investigations reveal a fracture which can be appropriately treated. This policy is cost efficient and improves the short term outcome.

Introduction: With the advent of harder wearing metal alloys such as cobalt chrome the technique of hip surface replacement has been resurrected. It is becoming an increasingly popular especially with the younger patient with end-stage hip arthritis. In this study we seek to demonstrate this procedure’s short term success rate for Cappagh and to demonstrate the new Joint Registry in action which has been collating data for the last 2 years.

Methods: The Bluespiers online database was used to identify 200 consecutive primary hip resurfacing performed in Cappagh National Orthopaedic Hospital between January 1st 2006 and January 31st 2008. Patients completed a WOMAC 3.1 Osteoarthritis assessment and SF-36 General Health survey before their operation and at their 1st Joint Registry Clinic Review, typically between five and 9 months post-operatively.

Findings: 200 hip resurfacing procedures by 7 surgeons were identified between January 1st 2006 and January 31st 2008. The mean patient age was 55 years(range, 23 to 81 years). 48 (32%) were female and 152 (68%) were male. Two post-operative femoral neck fractures were recorded which were converted to THR.

We used the SF-36 score as a surrogate marker of overall subjective health and quality of life. The average preoperative SF-36 score was 50.93 (5 to 94.4). The average SF-36 score at 1st Joint Review Clinic visit was 77.55 (23.77–100). This demonstrates an average improvement of 24.44 (−17.69 to 59.75)

As a measure of arthritis severity we will use the WOMAC 3.0 score as a surrogate. The average preoperative WOMAC score was 52.95 (4–92) and the average WOMAC score at 1st Joint Registry Review was 16.11 (0–75). This demonstrates an average decrease in WOMAC score of 34.46 (−29 to 83)

Discussion: Hip surface replacement in Cappagh as recorded by the Joint registry has good success in treating hip arthritis with good improvement of quality of life. We would hope to demonstrate with the joint registry continuing long-term success of this treatment.

Introduction: Fasting overnight NPO (Nulla per os) has been routine before surgery for the past century. The practice was previously designed to reduce the risk of pulmonary aspiration on induction. However this practice has been challenged over the recent years and is changing anaesthetic practices are now more liberal. There are many new concepts aimed at improving patient outcome by regulating metabolic, endocrine, inflammatory and immune responses. This combined with better patient satisfaction and lower anxiety has led to research in this area.

Overnight fasting can induce post operative insulin resistance. Insulin resistance is related to infectious morbidity and increased hospital length of stay (HLOS). Previously this concept was only important in diabetic patients. Surgery places the body under metabolic stress and even a short period of fasting will change the metabolic state of the patient. Indeed physical trauma can cause a triad known as the “diabetes of injury”: insulin resistance, hyperglycaemia and glucose intolerance. Preparation for surgery by maintaining a fasted state and catabolic metabolism may have deleterious consequences for the patient.

Previous studies on elective patients has shown that pre operative carbohydrate loading can reduce insulin resistance and mitigate the inflammatory response by immunomodulation. It has not previously been shown to have an effect in the hip fracture population. This particular group of patients are often elderly and require medical and anaesthetic work up. This delay can mean that the patient is kept fasting for prolonged periods and often overnight.

Methods: With full ethical approval at Connolly Hospital we prospectively randomised all femoral and hip fractures for surgery. We excluded diabetics and pregnant women from the study. A high carbohydrate drink called Nutritia Pre Op was selected. Random serum glucose was taken on admission. Patients were randomised and selected for the trial by hidden ballot. Anaesthetic approval was sought for each case. We compared our standard treatment for hip and femoral fractures of strict NPO prior to surgery versus giving patients the Pre Op drink. Each carton was 200ml and up to 4 were given the night before surgery. In the morning the patients were given another 2 drinks. There was a strict minimum 2 hour NPO period before leaving the ward. Glucose levels were then taken at 1 and 12 hours post operatively to assess whether hyperglycaemia was present. As per laboratory values a normoglycaemia was considered as 4–6mmol/l. Gender, age, type of operation, HLOS, complications and re-admissions were noted.

Results: In total 17 patients were enrolled in the study. Group A had 9 patients and were kept NPO as the control group. Group B had 8 patients enlisted in the Pre Op Drink group. In group A, 6 of 9 (67%) patients had a post operative hyperglycaemia. Average age in group A was 79.6 years with an average HLOS of 15.8 days. 4 patients between them required 8 readmissions over a 3 month post operative period. Group B showed 2 out of 8 (25%) patients had a hyperglycaemia. They had an average age of 69 years with an average HLOS of 11.75 days. 4 patients required 4 readmissions.

Conclusions: Pre Op high carbohydrate drinks significantly decrease post operative hyperglycaemia as per the laboratory ranges. This in turn supports that it decrease insulin resistance by preparing the body for surgery in a fed state. In the same way that one would not prepare for a marathon by fasting 24 hours before hand so the body recognizes that the surgical stress is not best dealt with when in a fasted state. The control group had twice as many readmissions and a longer HLOS. Previous studies show that there is decreased anxiety, thirst and hunger both pre and post operatively. We have shown that this is a safe drink to give and that post operative hyperglycaemia was better controlled.

Aim: It is widely accepted that surgical skills improve with experience. Part of this experience comes from operating on patients while honing new skills. Total hip arthroplasty is one such procedure. This paper examines outcomes in relation to the primary surgeon

Methodology: All patients who had an Exeter femoral component implanted and 2 years follow-up in the hospital joint register had their X-Ray, outcome scores and complications reviewed. Complications are routinely recorded as part of the joint register and hospital computer discharge system. Radiological outcome measures were taken as recommended by Johnston et al. Procedures were recorded as either performed by consultant surgeon or registrar supervised by consultant surgeon.

Results: Post operative WOMAC scores at six months and 2 years were similar in both groups (Consultant 19.6, registrar 22.32 at 6 months) SF-36 figures were similar at six months (Consultant performed 78.56, consultant supervised 75.39). There was a difference in SF-36 at 2 years (72.77 vs 63.11) but this was not statistically significant. Average abduction angle was lower in consultant supervised than consultant performed procedure. (36.75 vs 47 deg) Barrack cement grading was similar in both groups. Consultant inserted stems were more likely to be in neutral position compared to consultant supervised stems (84% vs 56%)

Conclusion: In both goups the quality of life indexes do show a difference in outcome which relates to the primary surgeon. However decreased abduction angle may lead to decreased range of motion post operatively and should be addressed intraoperatively.

The cement-in-cement femoral revision is a possible method of reducing complications. During recent research on this revision it was observed that a number of the inner cement contained macropores. It was hypothesized that porosity of the mantle influenced the subsidence and inducible displacement of the revision stems. The aim was to calculate the porosity and assess its relationship to the above factors.

Primary cement mantles were formed by cementing a stem into sections of tubular steel. At this stage, the specimen was chosen to be in a test or a control group. If in the test group, it underwent a fatigue of 1 million cycles. This was carried out in a fatigue machine mounted with a specifically designed rig. If in the control group, no such fatigue was undertaken. Into these fatigued and unfatigued mantles, the cement-in-cement procedure was performed. Both groups underwent a fatigue of again 1 million cycles. Subsidence and inducible displacement was recorded. The composites were then sectioned and photographed. The images underwent image analysis to calculate the porosity.

Multiple regression and a general linear model showed subsidence was inversely correlated to the porosity of the “fresh cement” in Gruen zones 3 and 5 (p = 0.021, R2 = 0.36). This relationship was not expected. The reason could be related to the fact that the migration of the stems in each separate direction was not monitored. Inducible displacement was inversely correlated to porosity of the inner cement, again in Gruen zones 3 and 5 (p = 0.001, R2 = 0.61). A possible explanation is that the stem was able to subside more due to the higher porosity and find a more stable position.

The subsidence and inducible displacement of these stems is influenced by porosity, specifically by the porosity of the distal inner cement.

One method of reducing intra-operative complications in revision hip surgery is the cement-in-cement technique. Some concern exists regarding the retention of the existing fatigued cement mantle. It was hypothesised that leaving the existing fatigued cement mantle does not degrade the mechanical properties of the cement in cement revision construct. The aim of this research was to test this hypothesis using in vitro fatigue testing of analogue cement in cement constructs.

Primary cement mantles were formed by cementing a large polished stem into sections of tubular stainless steel using polymethylmethacrylate with Gentamicin. At this stage, the specimen was chosen to be in the test group or the control group. If in the test group, it underwent a fatigue of 1 million cycles. This was carried out in a specifically designed rig and a fatigue testing machine. Into these fatigued and unfatigued primary mantles, the cement in cement procedure was carried out. Both groups underwent a fatigue of again 1 million cycles. Subsidence of the stems and their inducible displacement was recorded. A power calculation preceded testing.

Completion of a Mann Whitney test on the endpoints of the subsidence curves revealed that there is no statistical difference between the data sets (means 0.51, 0.46, n=10 + 10, p = 0.496). This data was also calculated for the inducible displacement. Again, there was no statistical difference in the separate groups for this parameter (means 0.38, 0.36, p = 0.96). This methodology produces a complex 3 dimensional reconstruction of the cement in cement revision which replicates the in vivo structure. This reconstruction has undergone fatigue testing. Neither of these two aspects has been produced for the study of cement in cement revision before.

A fatigued primary cement mantle does not appear to degrade the mechanical properties of the cement in cement revision construct

Introduction: It is standard procedure in our unit to use compartment pressure monitoring in all patients presenting with tibial fractures. A sustained difference of less than 30mmhg between the diastolic blood pressure and the compartment pressure (known as the delta pressure) is taken as an indication for fasciotomy.

Aim: To review the impact continuous compartment pressure monitoring has on the management of patients with tibial fractures.

Methods and materials: Between January 2004 and June 2006, 28 patients admitted to our unit following tibial fracture had a compartment pressure monitor inserted. The outer sheath from a 16G cannula connected to an arterial manometer was used in each case.

The records of these 28 patients were reviewed. Twenty three were male. Ages ranged from 19 to 83 years old. Eight patients had open fractures and 20 had closed fractures. Seven patients (25%) had difficulties with communication which could have impeded or delayed the diagnosis of a compartment syndrome.

Results: Average delta pressure ranged from nine to 69mmHg in our patient population. High energy injuries resulted in a significantly lower delta pressure (p=0.05). Open fractures were more likely to result from high energy, although this was not statistically significant (p=0.068). Two patients had fasciotomy performed based on clinical picture and a sustained decrease in delta pressure. No patient had a missed compartment syndrome.

Conclusion: Continuous compartment pressure monitoring is especially useful in patients who are most at risk for compartment syndrome i.e. those having sustained high energy injury or open fractures. It can also aid decision making when the clinical picture of compartment syndrome is equivocal, or when a patient’s ability to communicate pain is impaired.

However, due to the ease of use and the low cost involved, we recommend that all patients with tibial fracture should have continuous compartment pressure monitoring performed.

Impaction bone grafting with a cemented polished double-taper stem as a technique for revision of the femoral component was introduced in 1987 at our institution.

As at January 2000, 540 cases in 487 patients had been performed. All procedures have been studied prospectively and there are no patients lost to follow-up. We present the survivorship and outcome data for these patients.

Survivorship at 15 years is 90.6 percent [95 percent confidence interval: 88–93 percent]. Clinical scores show marked and sustained improvement.

There have been 45 failures [8.3 percent]. Technical error contributed to 13 of the 24 non-infective complications, but with improved technique plus the addition of long stemmed impaction grafting, there have been no technical errors since 1996.

Our results show that revision of the femoral component with impaction bone grafting is a reliable and durable technique with an acceptably low complication rate and with excellent survivorship at 15 years.

Antegrade intramedullary nailing of fractures of the shaft of the humerus is reported to cause impairment of the shoulder joint. We have reviewed 33 patients with such fractures to assess how many had injuries to the ipsilateral shoulder. All had an MR scan of the shoulder within 11 days of injury. The unaffected shoulder was also scanned as a control. There was evidence of abnormality in 21 of the shoulders (63.6%) on the injured side; ten had bursitis of the subacromial space, five evidence of a partial tear of the rotator cuff, one a complete rupture of the supraspinatus tendon, four inflammatory changes in the acromioclavicular joint and one a fracture of the coracoid process. These injuries may contribute to pain and dysfunction of the shoulder following treatment, and their presence indicates that antegrade nailing is only partly, if at all, responsible for these symptoms.

Aims Cemented acetabular components remain the standard for many surgeons around the world, however the main draw back of this technology is that of aseptic loosening. It has been suggested that loosening is initiated when mechanical failure occurs at the cement/bone interface. Successive generations of cementation techniques have evolved over the years in order to address this problem by improving the mechanical integrity of the cement bone construct. Negative pressure intrusion cementation techniques (NPI) represent a more recent phase of this evolution. These techniques involve the introduction of vacuum into the peri-acetabular bone immediately prior to cement application with the aims of decreasing the deleterious effects of the systemic bleeding pressure, removing fat and debris from the path of the advancing cement and causing deeper cement ingress through the direct effects of negative pressure. There exists in the literature very little scientific information relating to this technique; therefore our aim is to assess the quality of the cement bone interface in constructs created using a specially constructed rig.

Methods: Samples of screened, fresh frozen, human femoral head are machined to create a cylindrical core of cancellous bone measuring 24 x 40 mm. These samples are carefully stratified for porosity using a method of combing DEXA scan bone mineral density findings with microCT (Scanco 40, Bassendorf, Switzerland) histomorphological parameters. These cores are then introduced into the vacuum chamber of the rig and are subjected to a negative pressure of −30 kPa using a clinical suction machine (Cherion, Czech Rep). Simplex P (Stryker, Mahwah, US) polymethylmethacrylate cement is applied to the exposed cancellous bone within the rig and subjected to a constant positive external pressure via the vertical actuator of a servohydraulic materials testing machine (Instron 8873, Mass. US). The cement is allowed to set and the constructs are removed en bloc and frozen. The constructs produced are cylindrical and consist of three distinct zones; cement, bone and that of the cement bone interface. The quality of the cement bone interface is assessed in two distinct ways:

MicroCT is used to produce both quantitative and qualitative data relating to the cement bone interface. This data is processed using the 3D reconstruction software (Scanco, Bassendorf, Switzerland) to give values for intrusion depth and the integrity of cement bone interlock indicated using a previously published method of recording incidence and size of vacuolation within the cement bone interface.

Results: Early results indicate a tendency toward deeper and ‘tighter’ cement interdigitation within the cement bone interface in the samples created using the NPI method. These samples also tend to be mechanically stronger than controls.

Discussion This series of in-vitro experiments provides important information about this accepted but poorly understood technique. The model accurately mimics the operative technique and the use of microCT in this way is a novel application, allowi ng the digital assessment of cement intrusion depth and quality without having to physically section the constructs. It also attempts to relate these properties to mechanical strength.

Introduction: An arthroplasty database, such as the Swedish Hip Registry, provides a crude means of quality control over the sizable number of prosthetic implants available on the market today. It provides relatively rapid feedback on the performance of orthopaedic devices and surgical techniques, allowing inferior devices and methods to be discontinued. The maintenance of an arthroplasty register is inexpensive and of enormous benefit to the patient. At present, there is no nationwide arthroplasty register in operation in the Republic of Ireland.

Aim: To develop an arthroplasty register which prospectively captures all clinical, radiographic and medical outcome data on patients undergoing surgery in our unit

Materials and methods We are using an existing computer software programme (Bluespier Patient Manager) to capture our information, although our database is stored independently of this.

Data recorded includes medical outcome scores (WOMAC and MOS SF-36), patient data, operative details (including type of prostheses used and operative technique employed), inpatient course, and any postoperative events. For revision procedures, additional data such as location of bony defects (Gruen zones) and acetabular bone loss (Paprosky classification) are also recorded. Follow up in a special Joint Register Clinic is at six months, two years and every five years thereafter for primary procedures. This is reduced to every two years in the case of revision procedures.

To date, a pilot study involving four surgeons has prospectively captured data on 82 patients undergoing both primary and revision procedures in our unit. We aim to enrol all our patients in the register from July 2005, increasing the amount of data collected, which we hope will subsequently benefit patients undergoing hip and knee arthroplasty in the future.

Introduction: Impaction bone grafting in conjunction with a cemented polished double-taper stem as a technique for revision of the femoral component was introduced in 1987 at our institution.

Methods: As at January 2000, 540 cases in 487 patients had been performed by multiple surgeons. All procedures have been studied prospectively, and there are no patients lost to follow-up. We present the survivorship and outcome data for these patients.

Results: Survivorship at 15 years is 90.6 percent (95 percent confidence interval: 88–93 percent).

406 hips in 365 patients remain under active follow up, with 122 patients (134 hips) deceased.

Averaged clinical scores taken pre-operatively, 2 years post-operatively, and at latest follow-up show marked and sustained improvement: Charnley Pain 2.7, 5.5, 5.3; Charnley Function 2.1, 4.1, 3.6; Charnley Range of Motion 4.0, 5.4, 5.3; Harris Pain 19, 38, 36; Harris Function 18, 32, 28; and Oxford Hip Score 41, 22, 25.

There have been 45 failures (8.3 percent) at an average 7.6 year follow up (range 2.6 – 15.3 years). Technical error contributed to 13 of the 24 non-infective complications, but with improved technique plus the addition of long stemmed impaction grafting, there have been no technical errors since 1996.

Conclusion: Our results show that revision of the femoral component with impaction bone grafting is a reliable and durable technique with an acceptably low complication rate with excellent survivorship at 15 years.

Introduction and Aims: Impaction bone grafting in conjunction with a cemented polished double-taper stem as a technique for revision of the femoral component was introduced in 1987 at our institution. The aim of this study is to report on the outcome, survivorship, complications and radiological analysis of the first consecutive 540 cases performed in Exeter.

Method: As at January 2000, 540 cases in 487 patients had been performed by multiple surgeons. All procedures have been studied prospectively, and there are no patients lost to follow-up. We present the survivorship and outcome data for these patients.

Radiological analysis of the pre-operative, immediate post-operative and most recent follow-up radiographs was also performed. This included evaluation of the cement mantle and impacted allograft, stem subsidence within the cement mantle, presence of cortical healing and graft trabeculation on the follow-up radiographs, as well as appearance of radiolucencies and graft resorption.

Results: Survivorship at 15 years is 90.6 percent (95 percent confidence interval: 88–93 percent). Four hundred and six hips in 365 patients remain under active follow-up, with 122 patients (134 hips) deceased. Averaged clinical scores taken pre-operatively, two years post-operatively, and at latest follow-up, show marked and sustained improvement: Charnley Pain 2.7, 5.5, 5.3; Charnley Function 2.1, 4.1, 3.6; Charnley Range of Motion 4.0, 5.4, 5.3; Harris Pain 19, 38, 36; Harris Function 18, 32, 28; and Oxford Hip Score 41, 22, 25.

There have been 45 failures (8.3 percent) at an average 7.6-year follow-up (range 2.6–15.3 years). Technical error contributed to 13 of the 24 non-infective complications, but with improved technique plus the addition of long stemmed impaction grafting, there have been no technical errors since 1996.

Conclusion: Our results show that revision of the femoral component with impaction bone grafting is a reliable and durable technique with an acceptably low complication rate with excellent survivorship at 15 years.

This study was carried out to determine the incidence of shoulder injuries in the ipsilateral shoulder of patients who attended our unit with fractures of the humeral diaphysis.

This was a prospective study. 22 patients with fractures of the humeral diaphysis had an early (within 10 days of injury) MRI scan of the shoulder. The contralateral shoulder was also scanned as an internal control. There were 10 male and 12 female patients. The average age was 45 years. 20 were treated non-operatively, and 2 had retrograde intra-medullary nailing of the humerus. 6 patients in our study had a symmetrical MRI scan. The remaining 16 patients had some acute abnormality evident in the ipsilateral shoulder. 11 patients had a significant subacromial bursitis. 2 of these patients had a tear of the supraspinatus tendon. 1 patient had an undisplaced fracture of the coracoid process. The remaining 4 patients had significant AC joint inflammation, 3 being acute, the 4th being acute-on-chronic.

This study shows a high incidence of asymmetrical MRI scans, indicating a definite shoulder injury sustained at the time of the fracture of the humeral diaphysis. We therefore surmise that shoulder pain and dysfunction post antegrade intra-medullary nailing of the humerus may not be due to iatrogenic causes, but may in fact result from concomitant ipsilateral shoulder injury. To our knowledge, this is the first study demonstrating such an association.

Acetabular component loosening and pelvic osteolysis continue to be a significant clinical challenge in revision hip arthroplasty. We present results of 339 cases of acetabular reconstruction with impacted allograft.

All patients who under went acetabular reconstruction with impaction allograft between July 1995 and July 1999 were included. Clinical and radiographic data was collected prospectively.

There were 339 patients identified. Average age was 71 years. The majority were first time revisions (201) but the group includes 2nd, 3rd and 4th revisions with 34 two-stage revisions and 44 primary arthroplasties.

There were multiple surgeons with 2/3 being consultants and 1/3 fellows. Pre and post-operative clinical assessment included Oxford and Harris hip scores, and a modified Charnley score for pain, function and range of movement.

Pre-operative radiographs were classified with the Paprosky classification. Follow up radiographs were assessed for graft thickness, component migration, graft reabsorption and lucent lines.

There were 10 grade I, 205 grade II, and 103 grade III defects with 3 pelvic discontinuities. Reconstruction methods included impaction only, rim and/or medial mesh, KP plate fixation and reinforcement cages.

Follow up average was 6.1 years (4.3 – 8.4) and no patient was lost. Infection was identified in 13 patients (5 recurrent 89% eradication and 8 new 2.6%). There were 6 nerve injuries, 2 remain unresolved and 13 patients dislocated (3.8%). There have been 46 deaths in the group with 3 being peri-operative.

There have been 18 re-operations for aseptic loosening. 7 KP plates fractured, 1 cage migrated and 10 rim meshes failed.

Factors associated with aseptic loosening include use of a large rim mesh particularly with an allograft thickness of > 2cm.

We conclude that impaction allografting is a reliable method for acetabular reconstruction. Careful consideration should be given when allograft thickness will be > 2cm and a large rim mesh is required.

A comparison of the clinical status and outcome of a group of patients treated with tw-stage revision using either excision arthroplasty or an articulating spacer (the Kiwi Prostalac) as the first stage is presented.

Clinical scores were obtained before revision, after the first stage, and after the second stage revision, along with the outcome of the success of the revision procedure in terms of eradication of the infection, from the two study groups. Seven patients received excision arthroplasty and eight were treated with the Kiwi Prostalac spacer, at the treating surgeon’s discretion.

A comparison of the clinical status of the two groups will be presented at the varying stages of treatment, along with hospitalisation duration, and morbidity and ultimate outcome.

Our results demonstrate that two-stage revision with an antibiotic cement-coated THJR prosthesis (The Kiwi Prostalac) is an effective and safe method of managing deep peri-prosthetic infection around a THJR with significant advantages to the patient.

Impaction bone grafting in conjunction with a cemented polished double-taper stem as a technique for revision of the femoral component was introduced in 1987 at our institution.

As at January 2000, 540 cases in 487 patients had been performed by multiple surgeons. All procedures have been studied prospectively, and there are no patients lost to follow-up. We present the survivorship and outcome data for these patients.

Survivorship at 15 years is 90.6 percent (95 percent confidence interval:88–93 percent). Four hundred and six hips in 365 patients remain under active follow up, with 122 patients (134 hips) deceased.

Averaged clinical scores taken preoperatively, 2 years postoperatively and at latest follow up showed marked and sustained improvement: Charnley Pain 2.7, 5.5, 5.3; Charnley Function 2.1, 4.1, 3.6; Charnley Range of Motion 4.0, 5.4, 5.3; Harris Pain 19, 38, 36; Harris Function 18, 32, 28; and Oxford Hip Score 41, 22, 25. There have been 45 failures (8.3 percent) at an average 7.6 year follow up (range 2.6–15.3 years). Technical error contributed to 13 of the 24 non-infective complications, but with improved technique plus the addition of long stemmed impaction grafting, there have been no technical errors since 1996.

Our results show that revision of the femoral component with impaction bone grafting is a reliable and durable technique with an acceptably low complication rate with excellent survivorship at 15 years.

In 1993 a specialist limb length discrepancy and deformity clinic was established at Our Lady’s Hospital for Sick Children. Since then, the senior author has performed 193 lower limb lengthenings. Of these, there were 50 paediatric cases who had 74 segments lengthened using the Ilizarov method of distraction osteogenesis. A retrospective study of data and radiographic review of these children was performed. In particular, the grade of severity of deformity and complications encountered whilst lengthening were documented.

Complications were defined as any unwanted event and graded as minor or major with the major complications being further classed as serious or severe. Each patients deformity was classified using the Dahl Deformity Severity Scale which grades deformity according to percentage length discrepancy.

There were 26 females and 24 males in the study population, their average age being 13.1 years (range 2.8–18 years). 65% of the lengthenings had a congenital aetiology for the deformity. The mean hospital stay was 7 days and the average length achieved was 4.9cm. There were 79 minor complications and 48 major complications. The overall complication rate (total complications divided by the number of segments lengthened) was 1.74%.

This study shows how the Deformity Severity Scale may be used as a prognostic indicator to identify limb deformity at high risk of lengthening complication. It may also be used to determine the relative complication risk for each patient according to his or her percentage limb length discrepancy.

Acute haematogenous osteomyelitis remains a significant cause of morbidity in the paediatric population. The clinical presentation has changed, however, over the last number of decades. The typical picture of established osteomyelitis is less commonly seen. Children more often present with a less fulminant picture.

The treatment of acute haematogenous osteomyelitis remains controversial. Antibiotic therapy, initially intravenous, then orally, is the gold standard. Hover, the role of surgery is unclear. Some centres, particularly in North America treat 25–40% of patients surgically.

We present our experience with acute haematogenous osteomyelitis in children over a three year period. The total number of patients was forty-five. The mean age was 6.1 (range 6 months to thirteen years). The most common isolated organism was Staphylococcus Aureus. The mode of treatment was intravenous antibiotics for two weeks, or until clinical, and laboratory evidence of improvement, and the oral antibiotics for six weeks. No patients required surgical interventioin. All patients made a satisfactory recovery.

We conclude that the treatment of acute haematogenous osteomyelitis in the paediatric population should consist of antibiotic therapy only, and that there is no place for surgery.

We have carried out a blind, prospective study of 50 consecutive patients undergoing replacement arthroplasty of the hip using two different approaches. Clinical assessment, including the Harris hip score and a modified Trendelenberg test, and electrophysiological examination of the abductor muscles of the hip were undertaken before and three months after surgery. We found that 48% of patients had preoperative evidence of chronic injury to the superior gluteal nerve. Perioperative injury to the nerve occurred commonly with both approaches to the hip.

We did not find a significant correlation between injury to the superior gluteal nerve and clinical problems.