Arnaud Clavé

Polypropylene as a reinforcement in pelvic surgery is not inert: comparative analysis of 100 explants

Introduction and hypothesisCurrently, most implants used for reinforcement in surgical treatment of pelvic floor disorders are knitted monofilament polypropylene (PP). While previously recognized as inert, PP is associated with high complication rates. Some recent literature suggests polyester prosthetics based on poly(ethylene terephthalate) (PET), which may be more inert in vivo.MethodsA sample of 100 implants explanted from patients due to complications was examined to evaluate the relative degradation characteristics of PP and PET prosthetics. Histological, microscopic (scanning electron microscopy, SEM) and chemical analysis (Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC)) were conducted on these explants.ResultsPoly(ethylene terephtahlate) explants appeared to sustain less degradation in vivo than the PP explants observed in this cohort.ConclusionsThis is the first study to evaluate synthetic implants used in a vaginal approach for pelvic floor reinforcement. The study provides evidence contrary to published literature characterizing PP as inert in such applications. Additionally, the study suggests the need for clinical trials comparatively investigating the performance of new types of monofilament prosthetics, such as those comprising PET.

Efficacy of tranexamic acid on blood loss after primary cementless total hip replacement with rivaroxaban thromboprophylaxis: A case-control study in 70 patients.

INTRODUCTION Perioperative blood loss is a frequent cause of complications in total hip replacement (THR). The present prospective study assessed the efficacy of tranexamic acid (Exacyl(®)) in reducing blood loss in primary THR associated to rivaroxaban (Xarelto(®)) thromboprophylaxis. HYPOTHESIS Tranexamic acid associated to rivaroxaban reduces blood loss. MATERIAL AND METHOD A prospective case-control study included 70 primary cementless THRs performed by a single surgeon on a standardized technique, between September 2009 and September 2010. Thirty-seven patients received perioperative tranexamic acid; all patients received rivaroxaban thromboprophylaxis. RESULTS There was no significant difference between the two groups in terms of peroperative blood-loss volume or rates of thromboembolic or ischemic events or hematoma. Postoperative blood loss, D0-5 differential hemoglobinemia and real blood loss (in mL 100% hematocrit) were significantly lower in the tranexamic acid group. No transfusions were required in the tranexamic acid group, versus four in the control group. DISCUSSION Tranexamic acid associated to direct anti-Xa (antithrombin-independent) oral anticoagulants was effective in reducing postoperative blood loss, improving hemoglobinemia at 5 days and reducing transfusion rates. The results also confirmed the efficacy of and tolerance for rivaroxaban thromboprophylaxis in primary THR, with no clinical thrombotic events induced by the association of tranexamic acid with rivaroxaban. CONCLUSIONS Tranexamic acid is a simple means of reducing postoperative blood loss in THR, without increased risk of thromboembolism when associated to rivaroxaban thromboprophylaxis. LEVEL OF EVIDENCE Level III prospective case-control study.

Comparison of the inter- and intra-observer reproducibility of the Crowe, Hartofilakidis and modified Cochin classification systems for the diagnosis of developmental dysplasia of the hip.

INTRODUCTION Developmental dysplasia of the hip (DDH) leads to multiple treatment challenges during adulthood. Surgical treatment is mainly based on radiographic evaluation of the anatomical alterations. Several classification systems have been described in the published English scientific literature, but the French Cochin classification has not been used very much. Its primary advantage lies in its ability to intricately describe the DDH alterations with a large number of grades. We hypothesized that the inter- and intra-observer reproducibility of the SOFCOT-modified Cochin classification system was equal to that of the Crowe and Hartofilakidis classifications. MATERIAL AND METHODS Five French orthopaedic surgeons who were DDH experts classified 94 A/P pelvis radiographs (179 hips) using the Crowe (Cr), Hartofilikadis (Ha) and modified Cochin (Co) systems. This evaluation was repeated a second time one month later. The intra-observer reproducibility was determined with weighted Kappa and concordance coefficients. The inter-observer reproducibility was performed by calculating the multirater Kappa coefficient on each of the two data series. RESULTS For the intra-observer reliability, the average weighed concordance coefficients (95% CI) were 88.62-94.52 for Cr, 89.43-93.80 for Ha and 92.14-95.71 for Co. The average weighed Kappa coefficients (95% CI) were 0.70-0.85 for Cr, 0.67-0.82 for Ha and 0.75-0.83 for Co. For the inter-observer reliability, the Kappa for each assessment round was 0.57 and 0.48 for Cr, 0.43 and 0.44 for Ha, and 0.43 and 0.37 for Co. DISCUSSION The intra- and inter-observer reliability for the modified Cochin classification system is the same as the one for the Crowe and Hartofilakidis classifications. The theoretical advantage of this classification system should be confirmed by comparing the findings with intra-operative anatomical observations. LEVEL OF PROOF, TYPE OF STUDY IV.

Total talar fracture - inter- and intra-observer reproducibility of two classification systems (Hawkins and AO) for central talar fractures.

INTRODUCTION We evaluated the inter- and intra-observer reproducibility of two classification systems for central talar fractures (Hawkins, as modified by Canal and Kelly and then by us; AO/AOT). HYPOTHESIS The analysis and classification of these fractures will be better with CT scans than with X-rays. MATERIAL AND METHODS Four observers evaluated 39 X-ray and CT scan files twice in the span of six weeks; each evaluation entailed classifying the fractures and describing their main features. Cohens Kappa coefficient for inter-rater agreement was calculated and analysed. RESULTS The inter- and intra-observer reproducibility with CT scans was better with X-rays for most of the parameters evaluated. The modified Hawkins classification provided better reproducibility than the AO/AOT one. However, this classification system was not perfect, even after modifications and use of CT scans. DISCUSSION CT scans are an essential tool for the analysis of all talar fractures. We modified the Hawkins classification (as modified by Canal and Kelly) to include a Type 0 (no displacement or less than 2mm), include frontal body fractures that are displaced like neck fractures and take into account comminuted fractures and other trauma in the area. LEVEL OF PROOF IV - retrospective clinical study.

Midterm Survivorship of the Lefèvre Constrained Liner: A Consecutive Multisurgeon Series of 166 Cases

BACKGROUND Constrained liners are used as part of a salvage procedure to provide stability for patients at high risk for dislocation after a total hip arthroplasty. However, no recent studies exist highlighting their effectiveness and/or limitations. METHOD This prospective review included 166 consecutive hip arthroplasties, either primary (27%) or revision (73%), with a unique design of a constrained liner: Lefèvre retentive cup. There were 113 females (69%), and the average age at index surgery was 75.9 years (range, 35-94). The mean follow-up was 6.2 years (range, 0.3-11). RESULTS Twenty patients had a reoperation; 10 for infection (4 acute and 6 chronic joint infection) and 10 for cup failure (5 fixation failure, 3 aseptic loosening, and 2 dislocation). Ten-year survivals for cup revision were 89% (CI, 83-94) and 92% (CI, 89-97) for all revision and revision for noninfectious reasons, respectively. When solely evaluating for dislocation, the survival at 10 years was 99% (CI, 97-100). Considering primary and revision cases, 10-year survivals cup revision for aseptic reasons were 92.4% (CI, 84-100) and 92.5% (CI, 87-98), respectively. CONCLUSIONS The Lefèvre retentive cup demonstrated excellent 10-years survivorship. With the rate of aseptic loosening around 2% and a dislocation rate around 1%, the cup is as effective as other available devices and is therefore a cost-effective tool to reduce the risk of dislocation in at-risk patients undergoing hip arthroplasty.

Single-stage bilateral medial Oxford Unicompartmental Knee Arthroplasty: a case-control study of perioperative blood loss, complications and functional results

BACKGROUND The benefits and risks of a single-stage medial UKA remains a subject of debate because of the theoretically higher risk of complications and specifically blood loss. The aim of this study was to evaluate the perioperative blood loss, risks and the functional results of single-stage bilateral medial Oxford Unicompartmental Knee Arthroplasty (OUKA) compared to a standard unilateral medial OUKA procedure (control group). HYPOTHESIS The blood loss observed during bilateral single-stage medial Oxford UKA is not different from that of the control group. METHODS In this case-control prospective study, fifty patients (100 knees) who underwent single-stage bilateral medial OUKA (study group) were compared to a hundred patients (100 knees) with unilateral medial OUKA (control group), performed by the same surgeon. The real blood loss (in mL of hematocrit at 100%), incidence of blood transfusions, and complication rates were compared. Clinical results were assessed at 6 month and at a two-year minimum follow-up (FU) using IKS, KOOS and OKS scores, in addition to a satisfaction questionnaire. RESULTS Groups were deemed comparable. Concerning blood loss, no significant difference was observed compared to the control group (465mL±225 vs. 396±190; p=0.07). No difference was found, either, between groups regarding the complication rates (p=0.36), nor the clinical results (p=0.61) and patient satisfaction (p=0.23) at last FU. CONCLUSION Single-stage bilateral procedure does not cause increased blood loss compared with controls. Moreover, clinical results were deemed good and excellent in spite of a slightly greater complication rate than those found in the literature but similar to controls. LEVEL OF EVIDENCE Case-control study, level III.