We report the clinical and radiological outcomes of a series of contemporary cementless ceramic-on-ceramic total hip replacements (THRs) at ten years in patients aged ≤ 55 years of age. Pre- and post-operative activity levels are described. A total of 120 consecutive ceramic cementless THRs were performed at a single centre in 110 patients from 1997 to 1999. The mean age of the patients at operation was 45 years (20 to 55). At ten years, four patients had died and six were lost to follow-up, comprising ten hips. The mean post-operative Harris hip score was 94.7 (55 to 100). Radiological analysis was undertaken in 90 available THRs of the surviving 106 hips at final review: all had evidence of stable bony ingrowth, with no cases of osteolysis. Wear was undetectable. There were four revisions. The survival for both components with revision for any cause as an endpoint was 96.5% (95% confidence interval 94.5 to 98.7). The mean modified University of California, Los Angeles activity level rose from a mean of 6.4 (4 to 10) pre-operatively to 9.0 (6 to 10) at the ten-year post-operative period.

Alumina ceramic-on-ceramic bearings in cementless primary THR in this series have resulted in good clinical and radiological outcomes with undetectable rates of wear and excellent function in the demanding younger patient group at ten years.

Cite this article: Bone Joint J 2013;95-B:1603–9.

Introduction

The success of total hip arthroplasty has meant its indications have been extended to the younger more active patient. Due to the higher activity levels and increased demands of these patients, revision rates have been traditionally higher than when compared to older patients [1]. Ceramic on ceramic bearings may offer a viable long term solution as manufacturing methods have evolved resulting in improved mechanical properties, particularly of third and fourth generation ceramics. We report the outcome of primary cementless, alumina-on-alumina hip arthroplasty with a minimum 10 year follow up in 110 patients under the age of 55 years of age at time of surgery.

Aim

Alumina ceramic on ceramic bearings in total hip arthroplasty (THA) may reduce the prevalence of osteolysis due to its properties of low wear and chemical inertness. This is critical in the younger patient population as they place increased demands over a longer period. This study reports on the clinical and radiographic outcomes of a series of modern cementless ceramic on ceramic THA at a minimum of 10 years in this younger group.

Introduction

The Oxford Total Meniscal Knee (TMK by Biomet), is a total knee replacement with a multidirectional mobile bearing. As part of the evaluation of the TMK we compared our group of TMK knee replacements with an equivalent cohort of AGC total knee replacements.

Background

Pseudotumours have been associated with metal-on-metal (MoM) hip replacements. We define it as a solid mass which may have cystic components that is neither neoplastic nor infectious in aetiology. The cause of a pseudotumour is not fully understood but could be due to excessive wear, metal hypersensitivity or due to an as-yet unknown cause.

Aim

To evaluate safety and efficacy of performing a total knee arthroplasty (TKA) on patients receiving continuous Warfarin therapy

We report a case of a male patient presenting with bilateral painful but apparently well-positioned and -fixed large-diameter metal-on-metal hip replacements four years post-operatively. Multiple imaging modes revealed a thick-walled, cystic expansile mass in communication with the hip joint (a pseudotumour). Implant retrieval analysis and tissue culture eliminated high bearing wear or infection as causes for the soft-tissue reaction, but noted marked corrosion of the modular neck taper adaptor and corrosion products in the tissues. Therefore, we believe corrosion products from the taper caused by mismatch of the implant components led to pseudotumour formation requiring revision.

We evaluated the safety and efficacy of total knee replacement in patients receiving continuous warfarin therapy.

We identified 24 consecutive patients receiving long-term warfarin therapy who underwent total knee replacement between 2006 and 2008 and compared them with a group of age- and gender-matched patients not on long-term anticoagulation. Primary observations were changes in haemoglobin, transfusion rates and complications. Secondary observations were fluctuations in the international normalised ratio (INR) and post-operative range of movement.

There was no significant difference between the two groups in pre- or post-operative haemoglobin, incidence of transfusion or incidence of post-operative complications. There were no surgical delays due to a high INR level. The mean change in INR during the peri-operative phase was minimal (mean 0.4; sd 0.7). There was no significant difference in the range of movement between the two groups after day two post-operatively.

Current American College of Chest Physicians guidelines recommend bridging therapy for high-risk patients receiving oral anticoagulation and undergoing major orthopaedic procedures. We have shown that a safe alternative is to continue the steady-state warfarin peri-operatively in patients on long-term anticoagulation requiring total knee replacement.

Aim: To assess the impact of a proforma pathway on the care of patients following fractured neck of femur at Maidstone General Hospital compared to the gold standard set out in the British Orthopaedic Association and British Geriatric Society Blue Book – The Care of Patients with a Fragility Fracture.

Objectives: Initial audit of care prior to the introduction of the Proforma

Development of a multidisciplinary care pathway and proforma following BOA Standards for Trauma (BOAST) and National Hip Fracture Database (NHFD) guidelines

Background: The recent publication of the BOA and BGS Blue Book guidelines for care of patients with fragility fractures has defined a gold standard for the care of these patients. This has highlighted the areas of care that are commonly suboptimal and defined the requirements of a department providing ideal care. Both this, and the introduction of the NHFD and the resultant requirements for data collection and monitoring led us to develop a proforma for management and data collection.

Methods: An initial audit of care was performed. Notes were reviewed retrospectively for 62 patients and results were compared to the gold standard.

In June 2008 the proforma was implemented and data collected for reaudit (n=48). Direct comparison and statistical analysis was performed for the two groups of patients

Results: Comparison of the two audit groups shows dramatic and highly statistically significant differences in a number of areas of patient care, notably: mortality rates; appropriate A& E investigation and treatment; documentation of correct diagnosis and social history; mental test scoring; time to ward admission; time to surgery and osteoporosis treatment.

Discussion: The lack of a ring fenced, dedicated trauma ward leads to patients being admitted to outlying wards following fractured neck of femur. These wards are less likely to be as well equipped to deal with the unique requirements of these patients, which may explain the consistent problems with pressure area care and delay in discharge.

A strong recommendation for gold standard care is the provision of an orthogeriatric service with regular medical review both pre- and post-operatively. Currently no such dedicated service exists at Maidstone and this affects both the treatment of acute medical problems and the provision of falls investigation and treatment.

The introduction of the pathway has clearly benefitted the management of this difficult problem. With the support of the Rapid Improvement Program, further beneficial changes can be made to the care of patients following fractured NOF.

Aim: The aim of this study is to analyse the peri-operative complications of the Bimetric femoral hip prosthesis (Biomet UK Ltd) and to evaluate the osteo-conductive and osteo-inductive performance of HA coatings in this implant.

Materials and Methods: This is an ongoing randomised control study (retrieval) over a period of 4 years at William Harvey Hospital, Ashford, Kent. Three types of HA coatings were used – plasma sprayed HAC 60μm, bonemaster dense HAC 3μm, bonemaster graded HAC 7μm. Three retrieved implants were sent for histological examination at The Royal National Orthopaedic Hospital, Stanmore.

Results: Fifty Four patients with mean age of 77 years (66–89) were evaluated. There were 12 (22%) surgical complications- 9 (7.4%) periprosthetic fractures, 2 stems subsided, 1 stem cemented. There was 5.5 % (3/54) risk of revision in 4 years (p< 0.001). The histological photomicrograph with the three different coatings examined showed Bone master 3–7μm coating had excellent bony in growth (osteo-integration).

Conclusion: In our series there was 5.5% risk of revision rate. The periprosthetic fracture and early mortality rates are within national limits. Revision surgery is the most significant aspect and this should be our primary concern. Hydroxyapatite coated stems with newer technique coating promotes good osteo-integration.

Introduction: The JRI Furlong HAC LOL hemiarthroplasty stem has shown increased periprosthetic fracture rates compared to previous literature (15.2% vs 7.4%) [1,2,3]. This study seeks to identify a measurable radiographic index, the Metaphyseal-Diaphyseal Index (MDI) score to determine whether intra-operative fracture in osteoporotic bone can be predicted to influence the type of prosthesis used (cemented or uncemented).

Methodology: A 5 year prospective cohort of 560 consecutive patients underwent hemiarthroplasty (cemented or uncemented). A nested case-control study to determine risk factors affecting intra-operative fracture was carried out.

Clinical outcomes and radiographic analysis was performed. The Vancouver Classification was used to classify periprosthetic fracture.

The MDI score was calculated using radiographs, as a control (gold standard), Yeung’s CBR score was calculated [4]. See Figure 1. A receiver operating characteristic (ROC) curve was formulated for both and area under the curve (AUC) compared. Intra and inter-observer correlations were determined.

Cost analysis was also worked out.

Results: 407 uncemented and 153 cemented stems were implanted. The use of uncemented implants was the main risk factor for intra-operative periprosthetic fracture.

62 periprosthetic fractures occurred in the uncemented group (15.2%), 9 in the cemented group (5.9%), p< 0.001. The revision rate for sustaining a periprosthetic fracture (uncemented group) was 17.7%, p< 0.001 and 90 day mortality 19.7%, p< 0.03.

MDI’s AUC was 0.985 compared to CBR’s 0.948, p< 0.001. See Figure 2. The MDI score cut-off to predict fracture was 21, sensitivity 98.3%, specificity 99.8%, PPV 90.5%, NPV 98%. ANCOVA ruled out any other confounding factors as being significant.

The intra and inter-observer Pearson correlation scores were r=0.99, p< 0.001.

The total extra cost due to the intra-operative fractures was £93,780.

Discussion: The MDI score is a useful, cost effective way of preventing this serious complication from occurring. We recommend that any femur scoring 21 or less on the MDI score be considered for cemented hemiarthroplasty.

Level of evidence: Level 2 Diagnostic Study: Development of diagnostic criteria on basis of consecutive patients (with universally applied reference “gold” standard).

Introduction: The JRI Furlong HAC LOL hemiarthroplasty stem has shown increased periprosthetic fracture rates compared to previous literature(15.2% vs 7.4%). This study will seek to identify a measurable radiographic index, the Metaphyseal-Diaphyseal Index (MDI) score to determine whether intra-operative fracture in osteoporotic bone can be predicted to influence the type of prosthesis used (cemented or uncemented).

Methodology: Over 5 years prospectively, a cohort of 560 consecutive patients undergoing hemiarthroplasty (cemented and uncemented) were evaluated. Clinical outcomes and radiographic analysis was performed. The Vancouver Classification was used to classify peri-prosthetic fracture. The MDI score was calculated using radiographs from the uncemented group. As a control (gold standard), Yeung et al’s CBR score was also calculated. From this, a receiver operating characteristic (ROC) curve was formulated for both scores and area under the curve (AUC) compared. Intra and inter-observer correlations were determined. Cost analysis was also worked out for adverse outcomes.

Results: 407 uncemented and 153 cemented stems were implanted. 62 periprosthetic fractures occurred in the uncemented group (15.2%), 9 occurred in the cemented group (5.9%), p< 0.001. The revision rate for sustaining a periprosthetic fracture (uncemented group) was 17.7%, p< 0.001. MDI’s AUC was 0.985 compared to CBR’s 0.948, p< 0.001. The MDI score cut-off to predict fracture was 21, sensitivity 98.3%, specificity 99.8%, positive predictive value 90.5% and negative predictive value 98%. ANCOVA analysis ruled out any other confounding factors as being significant. The intra and inter-observer Pearson correlation scores were r=0.99, p< 0.001. The total extra cost due to the intra-operative fractures was ú40,140.

Discussion: The MDI score has been shown to be a potentially useful, cost effective way of preventing this serious complication from occurring. We recommend that any femur scoring 21 or less on the MDI score be considered for cemented hemiarthroplasty. Level of evidence: Level 2 Diagnostic Study: Investigating a diagnostic test against gold standard.

Introduction: Various surgical approaches have been described for the hip joint but the optimal surgical approach for total hip replacement remains controversial. The lateral approach & the posterior approach are the most commonly used approaches.

Various scoring systems are in use to assess the outcome of total hip replacement. Since its introduction in 1996, Oxford hip score (OHS) has been validated in several studies. Total hip replacement has been shown to improve the OHS in several studies but we could not find any studies on effect of the surgical approach on OHS.

AIM: To find out the affect of surgical approach on oxford hip score.

Methods: Exeter Primary Outcomes Study was a prospective non-randomised multicentre study involving six centres across the UK. Ethical committee approval was taken and the study was conducted over a period of five years. 1610 patients were included in the study. All the patients underwent primary hip replacement with Exeter stem AND were followed up in the clinics for pre-operative assessment and then at three months, year one, year two and year five post-operatively. Oxford hip score was noted at pre-operative assessment and postoperatively at three months, year one, two, three, four and five, either in the clinics or by post. All data was analysed in conjunction with a statistician using SPSS.

Results: We had 1587 patients with regular follow-up. Lateral approach was the most common surgical approach (n=1143) compared to posterior approach (n=436). Sex ratio for each surgical approach was comparable. Oxford hip scores significantly improved postoperatively (P < 0.05) up to four years, with both the surgical approaches. The posterior approach gave a better improvement in OHS compared to the lateral approach for all the four years. The absolute oxford hip scores improved significantly with the posterior approach for the first 12 months post-operatively.

CONCLUSION: Posterior approach gives greater patient perceived clinical benefit in the first year after surgery which could help in early rehabilitation compared to lateral approach. This should be considered when assessing the best approach for the patients.

We report the clinical and radiographic outcome of a consecutive series of 219 hydroxyapatite-coated total knee replacements with a follow-up of 5 to 8 years.

Patients who fulfilled the entry criteria were included in a prospective study from early 1997 to late 1999. Regular clinical & functional assessment was subsequently performed using the Knee Society Score, WOMAC & SF-12 self-assessment questionnaires. Analysis of fluoroscopically controlled radiographs was performed using the American Knee Society Score.

All living patients (186 knees) were followed-up. Exhaustive efforts were made to ensure that no patient was lost to follow-up. 28 patients (30 knees) were deceased. There have been 3 revisions.

The mean pre-operative Knee Score of 43.8 increased to 77.1 and the mean pre-operative Function Score of 20.3 increased to 63.4 at 5 years. The WOMAC scores also showed marked improvement from pre-operative status after 5 years minimum follow-up: pain 250 pre-op to 157, stiffness 115 pre-op to 56 and function 910 pre-op to 588.

There was no radiographic evidence of loosening or migration. The average American Knee Society Score for each component was 4. Small gaps between the bone-implant interface were observed to heal over the first year. A separate phenomenon of focal osteopenia is also described in a small number of well-fixed femoral components (12 of 219).

To date, 3 prostheses have been revised, 2 due to deep infection and 1 due to tibial tray subsidence. A survivor-ship of 98.6% has been achieved at 8 years.

We believe this to be the first medium term study for the Duracon HA coated knee arthroplasty system, showing excellent clinical and radiographic outcome, with 100% follow-up at 5 to 8 years.

Since 1986 the JRI Furlong hydroxyapatite coated femoral stem has been in use at our institution. We present the results of the first 100 hips performed on 86 patients by or under the direct supervision of one surgeon (JANS). The Furlong stem was used in conjunction with a ceramic head and CCI cemented UHDP cup. AT the time of surgery the mean age of the patients was 69 (range 45–94 years). One patient has undergone excision arthroplasty for suspected infection at which time the femoral component was found to be well bonded. At latest review, all patients were accounted for. 48 patients had died with no death directly related to surgery and no revisions or planned revision of the femoral component at the time of death. Of the 38 surviving patients (44 hips), the mean Merle d’Aubigné & Postel score was 5.8 for pain, 5.7 for movement and 4.9 for function at 13 to 16.5 years follow up (mean 14.0). No femoral component showed radiological evidence of loosening. Five acetabular components have been revised for aseptic loosening with the femoral component found to be well bonded at the time of revision and therefore left in situ. In this series of hydroxyapatite coated femoral stems the overall revision rate is 1% with no cases of aseptic loosening. This hydroxyapatite coated prosthesis, at long term follow up has superior survival figures to other types of femoral components.

MRI is a well-tolerated, short procedure that would provide an early, accurate and cost effective diagnosis in elderly patients with negative plain films and persistent post-traumatic hip pain, thereby facilitating their correct management.

It is 100% sensitive and specific to occult hip fractures and does not involve ionising radiation.

Fractured necks of femur in the elderly population are common. This group of patients are responsible for a significant proportion of health care costs and efforts today. The diagnosis of hip fractures is not always clear-cut and plain radiographs may not show an undisplaced fracture. The management of this patient group is dependant upon the correct diagnosis via imaging and treatment decisions are based on these findings. If these fractures are missed, there is a significant chance of displacement and avascular necrosis presenting at a later date. This would complicate matters and result in more complex surgery. This also increases health care costs due to an extra admission, more expensive and difficult surgery with longer rehabilitation and after care. In our study, the management of the patients reviewed was significantly altered due to the imaging process used.

We performed MRI scans on thirty-six patients who had post-traumatic hip pain and negative plain radiographs (reported as normal or equivocal). Twenty-three (64%) of the patients sustained a fracture, of which sixteen (44%) involved the neck of the femur, all of whom were above the age of 71 years. 100% of the elderly age group scanned were positive for a femoral neck fracture and eleven (31%) received operative intervention. The five patients who did not undergo operative management were deemed too unwell for surgery. Only three patients’ scans were negative.

These results confirm that MRI (in the 71 years and above age group), is indicated in order to diagnose an undisplaced fractured neck of femur not recognised on plain radiographs, which requires operative intervention in the form of dynamic hip screw or cannulated hip screws to prevent further deterioration or displacement.