Introduction

Hydroxyapatite (HA) coated femoral stems require a press fit for initial stability prior to osteointegration occurring. However this technique can lead to perioperative femoral fracture.

The medium term results of the JRI Furlong Total hip replacement have been very impressive to date. We report the longest prospective series to date of a hydroxyapatite coated femoral prosthesis (Joint Replacement Instrumentation limited, London, UK) at 15–21 years follow up. We describe the long term clinical and radiological femoral stem survival of 331 consecutive JRI Furlong Hydroxyapatite coated total hip replacements in 291 patients at an average follow-up of 17.5 years (15 – 21 year). Two patients (0.6%) were lost to follow-up over the 21 years of the study period. Using revision of the femoral stem for any reason as an endpoint, we report a stem survival of 97.4 % (81.0 to 99.5). Using Aseptic loosening as an endpoint, stem survival was 100%.

The average Merle, D’Aubine & Postel scores recorded for the patients was 5.63/6 for Pain, 5.42/6 for mobility and 4.50/6 for function. There were no cases of anterior thigh pain relating to the uncemented femoral stem.

These results compare favourably with the best long term survival of cemented or uncemented femoral stems used in total hip replacements.

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.

The aim of this study was to compare two types of knee arthrodesis.

Fourteen patients underwent arthrodesis of the knee in a single institution. Seven had a customised coupled nail (the Mayday arthrodesis nail), and six had external fixation applied, one patient had both procedures undertaken. Twelve patients had infected knee arthroplasty, one had recurrent dislocation following arthroplasty and one had an infected open meniscetomy. Comparison was made with the external fixation in which only two cases achieved bony union compared with all eight (100%) using the customised nail. Time to bony union was also considerably shorter in the later group, as was the length of hospital stay.

We conclude that a customised intra-medullary nail is a superior method of knee arthrodesis compared with external fixation.

Between 1986 and 1991 we implanted 331 consecutive Furlong hydroxyapatite-coated femoral components of a total hip replacement in 291 patients. A cemented acetabular prosthesis was used in 217 hips and a hydroxyapatite-coated component in 114. We describe the long-term clinical and radiological survival of the femoral component at a mean follow-up of 17.5 years (15 to 21). Only two patients (0.68%) were lost to follow-up. With revision of the femoral component for any reason as the endpoint, the survival at a mean of 17 years was 97.4% (95% confidence interval 94.1 to 99.5), and with revision for aseptic loosening as the endpoint it was 100%. The survival at a maximum of 21 years with revision of the femoral component for any reason as the endpoint was 97.4% (95% confidence interval 81.0 or 99.5). These results compare favourably with the best long-term results of cemented or uncemented femoral components used in total hip replacement.