title: The suitability of an uncemented hydroxyapatite coated (HAC) hip hemiarthroplasty stem for intra-capsular femoral neck fractures in osteoporotic elderly patients: the Metaphyseal-Diaphyseal Index, a solution to preventing intra-operative periprosthetic fracture.
abstract: 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.A 5 year prospective cohort of 560 consecutive patients, undergoing hemiarthroplasty (cemented or uncemented), was evaluated. A nested case-control study to determine risk factors affecting intra-operative fracture was carried out. The Vancouver Classification was used to classify periprosthetic fracture. The MDI score was calculated using radiographs from the uncemented group. As a control (gold standard), Yeung et al's Canal Bone Ratio (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. Four hundred and seven uncemented and one hundred and fifty-three cemented stems were implanted. The use of uncemented implants was the main risk factor for intra-operative periprosthetic fracture. Sixty-two periprosthetic fractures occurred in the uncemented group (15.2%), nine 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 and 90 day mortality 19.7%, P < 0.03. 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%. Multivariate regression 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. JRI uncemented hemiarthroplasty has a significantly higher intra-operative fracture rate. We recommend cemented arthroplasty for hip fractures. We propose a radiographic system that may allow surgeons to select patients who are good candidates for uncemented arthroplasty, but it needs prospective validation.
authors.affiliation: Department of Trauma & Orthopaedics, Queen Elizabeth Hospital, South London Healthcare NHS Trust, Stadium Road, Greenwich, London, SE18 4QH, UK. rishi.chana1@btopenworld.com
authors.forename: Rishi
authors.initials: R
authors.lastname: Chana
authors.forename: Reza
authors.initials: R
authors.lastname: Mansouri
authors.forename: Chris
authors.initials: C
authors.lastname: Jack
authors.forename: Max R
authors.initials: MR
authors.lastname: Edwards
authors.forename: Ravi
authors.initials: R
authors.lastname: Singh
authors.forename: Carmel
authors.initials: C
authors.lastname: Keller
authors.forename: Farid
authors.initials: F
authors.lastname: Khan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D001672:Biocompatible Materials / Q000627:therapeutic use; D001843:Bone Cements / Q000627:therapeutic use*; D016022:Case-Control Studies; D003365:Costs and Cost Analysis; D017886:Durapatite / Q000627:therapeutic use; D005260:Female; D005265:Femoral Neck Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D007431:Intraoperative Complications / Q000191:economics / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D057068:Periprosthetic Fractures / Q000191:economics / Q000209:etiology* / Q000517:prevention & control; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D017886:Durapatite
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