A randomized, double-blind, placebo-controlled trial on the efficacy of tranexamic acid combined with rivaroxaban thromboprophylaxis in reducing blood loss after primary cementless total hip arthroplasty.

AIMS: Cementless primary total hip arthroplasty (THA) is associated with risks of bleeding and thromboembolism. Anticoagulants are effective as venous thromboprophylaxis, but with an increased risk of bleeding. Tranexamic acid (TXA) is an efficient antifibrinolytic agent, but the mode and timing of its administration remain controversial. This study aimed to determine whether two intravenous (IV) TXA regimens (a three-hour two-dose (short-TXA) and 11-hour four-dose (long-TXA)) were more effective than placebo in reducing perioperative real blood loss (RBL, between baseline and day 3 postoperatively) in patients undergoing THA who receive rivaroxaban as thromboprophylaxis. The secondary aim was to assess the non-inferiority of the reduction of blood loss of the short protocol versus the long protocol. PATIENTS AND METHODS: A multicentre, prospective, randomized, double-blind, placebo-controlled trial was undertaken involving 229 patients undergoing primary cementless THA using a posterior approach, whose extended rivaroxaban thromboprophylaxis started on the day of surgery. There were 98 male and 131 female patients, with a mean age of 65.5 years (32 to 91). The primary outcome, perioperative RBL, was evaluated at 72 hours postoperatively. The efficacy of short- and long-TXA protocols in the reduction of perioperative RBL was compared with a placebo group. RESULTS: TXA significantly reduced perioperative blood loss compared with placebo (p < 0.001); the mean differences were 525.3 ml (short-TXA vs placebo) and 550.1 ml (long-TXA vs placebo). No venous or arterial thromboembolic complications were reported. The upper boundary of the 95% confidence interval, when comparing short and long protocols, was below the pre-specified margin of non-inferiority (p = 0.027). CONCLUSION: In patients undergoing primary cementless THA, using a posterior approach, who are treated with rivaroxaban for thromboembolic prophylaxis, short- and long-TXA IV protocols are significantly more effective than placebo in reducing perioperative RBL, without any thromboembolic complications. Non-inferiority of a short- versus a long-TXA protocol in reducing perioperative RBL was supported in a secondary analysis.

Reproducibility of length measurements of the lower limb by using EOS™.

BACKGROUND: Lower-limb discrepancy following total hip arthroplasty is the third-most common reason for patient dissatisfaction in orthopaedic surgery. Therefore, accurate planning and evaluation methods are mandatory. The main aim of this study was to evaluate the reliability of the EOS™ system by establishing and comparing the reproducibility of lower-limb automatic and manual 3D measurements. We hypothesized that the reproducibility of the lower-limb measurements is similar regardless of the method used and with an agreement higher than 0.95 for the length parameters. MATERIALS AND METHODS: This study utilized an EOS radiological database of 112 patients. Two independent observers performed two rounds of lower-limb measurements twice, either in manual 3D or automatic 3D mode. The intra- and inter-observer reproducibility was evaluated by the calculation of the intra-class coefficient for each measurement method. The methods were then compared. RESULTS: The intra- and inter-observer reproducibility for length measurements found with the manual and automatic 3D methods was always > 0.98. There was no significant difference in the reproducibility between the two measurement modes, with the exception of the offset, hip-knee-shaft, and neck-shaft angles. CONCLUSION: Our results indicate a very good reproducibility of EOS™ length measurement, regardless of the method used. Automated 3D mode is preferred for the collection of angular and offset measurements. Furthermore, manual mode measurements are not affected by surgical history. Level of evidence IV.

Radiological Decision Aid to determine suitability for medial unicompartmental knee arthroplasty: development and preliminary validation.

AIMS: An evidence-based radiographic Decision Aid for meniscal-bearing unicompartmental knee arthroplasty (UKA) has been developed and this study investigates its performance at an independent centre. PATIENTS AND METHODS: Pre-operative radiographs, including stress views, from a consecutive cohort of 550 knees undergoing arthroplasty (UKA or total knee arthroplasty; TKA) by a single-surgeon were assessed. Suitability for UKA was determined using the Decision Aid, with the assessor blinded to treatment received, and compared with actual treatment received, which was determined by an experienced UKA surgeon based on history, examination, radiographic assessment including stress radiographs, and intra-operative assessment in line with the recommended indications as described in the literature. RESULTS: The sensitivity and specificity of the Decision Aid was 92% and 88%, respectively. Excluding knees where a clear pre-operative plan was made to perform TKA, i.e. patient request, the sensitivity was 93% and specificity 96%. The false-positive rate was low (2.4%) with all affected patients readily identifiable during joint inspection at surgery. In patients meeting Decision Aid criteria and receiving UKA, the five-year survival was 99% (95% confidence intervals (CI) 97 to 100). The false negatives (3.5%), who received UKA but did not meet the criteria, had significantly worse functional outcomes (flexion p < 0.001, American Knee Society Score - Functional p < 0.001, University of California Los Angeles score p = 0.04), and lower implant survival of 93.1% (95% CI 77.6 to 100). CONCLUSION: The radiographic Decision Aid safely and reliably identifies appropriate patients for meniscal-bearing UKA and achieves good results in this population. The widespread use of the Decision Aid should improve the results of UKA. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):3-10.

Radiographic outcomes in the coronal plane with iASSIST™ versus optical navigation for total knee arthroplasty: A preliminary case-control study.

BACKGROUND: The new navigation system iASSIST™ for total knee arthroplasty (TKA) relies on accelerometers and gyroscopes. The objective of this prospective study was to compare the accuracy of iASSIST™ to that of the conventional optical navigation system Navitrack™ by determining the rate of mechanical axis restoration (±3°), postoperative mean mechanical alignment, rate of adequate femoral and tibial component positioning, mean operative time, and occurrence of navigation-related adverse events. HYPOTHESIS: The rate of mechanical axis restoration (±3°) is not lower with iASSIST™ than with the conventional navigation system Navitrack™. MATERIAL AND METHODS: Of 40 patients who underwent primary TKA between October 2013 and March 2014, 20 had navigation using iASSIST™ and 20 using Navitrack™. Six months after TKA, an independent observer measured three parameters on coronal radiographs: the hip-knee-ankle angle (HKA), the mechanical lateral distal femoral angle (mLDFA), and the mechanical medial proximal tibial angle (mMPTA). RESULTS: The two groups showed no significant differences for the rates of HKA restoration (P=0.3), adequate coronal positioning of the femoral component (P=0.12) and tibial component (P=0.12), or optimal success (P=0.09). Significant differences in favour of iASSIST™ were demonstrated for the values and angular deviations of the HKA (P=0.02) and mMPTA (P=0.01), whereas no significant difference was found for mLDFA. There were no significant differences regarding the mean operative time (P=0.06) or the occurrence of navigation-related adverse events (P=0.18). DISCUSSION: The iASSIST™ system provides a neutral mechanical axis and optimal component position in the coronal plane in 95% of cases, indicating that it is as accurate as the optical navigation system Navitrack™. LEVEL OF EVIDENCE: III, prospective case-control study.

Influence of experience on intra- and inter-observer reproducibility of the Crowe, Hartofilakidis and modified Cochin classifications.

INTRODUCTION: A previous study demonstrated that the reproducibility of the Crowe (Cr), the Hartofilakidis (Ha) and the modified Cochin (Co) classifications were comparable. However, there were differences with a trend that suggested the influence of experience. Therefore, we performed a prospective study to investigate whether experience influenced the reproducibility of the commonly used developmental dysplasia of the hip (DDH) classifications. HYPOTHESIS: The hypothesis was that the intra- and inter-observer reproducibility scores would be higher in the senior group than the junior group, and particularly for the modified Co classification. METHODS: Four seniors and four residents classified 104 A/P pelvic radiographs (200 hips) two times using the Cr, Ha and Co classification systems. RESULTS: For intra-observer reproducibility, the average weighted concordance coefficients [95% confidence intervals] were for the senior and the junior groups: 92.2 [88.6-95.7] and 92.6 [87.9-97.2] for Cr, 92.1 [88.7-94.6] and 92.0 [87.7-96.3] for Ha, 94.2 [91.8-96.6] and 94.1 [91.5-96.6] for Co. The average weighted Kappa (95% confidence intervals) were 0.8 [0.71-0.88] and 0.79 [0.68-0.89] for Cr, 0.77 [0.74-0.81] and 0.75 [0.62-0.88] for Ha, 0.82 [0.76-0.89] and 0.80 [0.74-0.87] for Co. The junior inter-observer reproducibility multi-rater Kappa (list A:list B) were 0.57:0.50 (Cr), 0.47:0.53 (Ha), 0.42:0.42 (Co). Senior multi-rater Kappa were 0.53:0.49 (Cr), 0.40:0.34 (Ha), 0.40:0.43 (Co). CONCLUSIONS: Contrary to our hypothesis, the experience of the observer did not affect the intra- and inter-observer reproducibility of the three classification systems.

Aetiology of lateral progression of arthritis following Oxford medial unicompartmental knee replacement: a case-control study.

PURPOSE: The aim of this case-control study is to assess for predictive factors that may determine development of lateral compartment progression after Oxford medial unicompartmental knee replacement. METHODS: Twenty-eight patients who were revised as a result of lateral osteoarthritis progression were matched to 52 alive and unrevised patients. Body mass index, intra-operative findings, postoperative leg alignment, meniscal bearing size and histological findings have been analysed. Radiological analysis was carried out on the immediate postoperative radiographs by two blinded observers to assess the severity of arthritis in the lateral compartment. The measurements of the components positions were converted into binary figures as to whether they were inside or outside the recommended limits for analysis. Conditional logistic regression was used to identify important predictors of progression, taking into account the case-control grouping. RESULTS: The results shows that the condition of the lateral compartment is a significant predictor for developing subsequent lateral compartment arthrosis (OR 2.627, p = 0.019). The study showed no relationship between progression of arthritis and component position (OR [0.5-1.18], p [0.21-1]). Nor have it demonstrated that BMI (OR 1.06, p = 0.61), postoperative leg alignment (OR 1.26, p = 0.636), meniscal bearing size (1.32, p = 0.307) or presence of chondrocalcinosis (OR 0.35, p = 0.36) have any association with lateral osteoarthritis progression. CONCLUSIONS: This study showed the importance of excluding radiographic evidence of lateral compartment osteoarthritis on the preoperative radiograph prior to medial unicompartmental knee replacement. We have not been able to show any relationship between progression of arthritis and component position. Level of proof Case-control study, level III.

Can computer-assisted surgery help restore leg length and offset during THA? A continuous series of 321 cases.

INTRODUCTION: Total hip arthroplasty (THA) can bring about complications - particularly leg length differences - that are becoming increasingly litigious. Computer-assisted orthopedic surgery (CAOS) can help optimize the procedure, but its ability to effectively restore leg length is controversial. As a consequence, we carried out a study to determine: (1) its contribution to meeting leg length and offset objectives, (2) its reliability, by evaluating the correlation between radiological and navigation data, (3) its safety, by evaluating navigation-specific and non-specific complications. HYPOTHESIS: CAOS will help to restore leg length within ± 5 mm in more than 80% of cases. MATERIAL AND METHODS: A series of 321 continuous cases of cementless THA implanted through the posterolateral approach using CAOS was analyzed retrospectively. With a minimum 1 year follow-up, we evaluated whether the leg length and offset goals were achieved, how well the navigation and radiology data were correlated and whether navigation-specific and non-specific complications occurred. Based on our hypothesis that 80% of patients would have less than 5 mm leg length difference and the null hypothesis (PA = P0) with an alpha of 0.05, 200 observations were required to achieve a power of 90%. RESULTS: The leg length and offset objectives were achieved in 83.3% and 88% of cases, respectively. Twenty-two patients required a heel wedge to compensate for leg length differences. The correlation between the radiology and surgical navigation data was satisfactory - the Pearson coefficient was 0.79 for length and 0.74 for offset. Intraoperative and postoperative complications or adverse events were found in 14.6% of cases; these were specific to CAOS in 12.1% of cases and non-specific in 2.5% of cases. CONCLUSION: This study shows the relevance of CAOS for achieving preoperative leg length objectives, with good correlation between navigation and radiology data, and without major complications. LEVEL OF EVIDENCE: IV - retrospective study.

Comparison of the reliability of leg length and offset data generated by three hip replacement CAOS systems using EOS™ imaging.

INTRODUCTION: Computer-assisted orthopaedic surgery (CAOS) theoretically will help to optimise total hip arthroplasty (THA) results. Although CAOS systems have become more sophisticated, they are not widely used, partially because of their suspect reliability. To assess reliability of these systems, we carried out a study with multiple objectives in mind: (1) establish and compare the accuracy of the leg length (LL) measurement from three CAOS systems; (2) analyse the correlation of LL and offset data generated by these CAOS systems with those of the EOS™ imaging system; (3) determine if the goals of leg length restoration with ±2 and ±5 mm were achieved; (4) evaluate why certain cases fails. HYPOTHESIS: The three CAOS systems have the same accuracy for LL, and their error is less than or equal to 0.6mm. MATERIAL AND METHODS: We retrospectively studied 106 cases of primary THA where preoperative and postoperative measures of leg length had been performed with an EOS™ imaging system. The cases were placed in three groups, depending on which CAOS system had been used: group A (Amplivision™, amplitude), group B (Hip Express™, Brainlab), group P (THS™, Praxim). The accuracy of the leg length data was calculated by finding the difference between the data from each CAOS system and the gold-standard EOS measurements. RESULTS: The leg length accuracy was -0.846 [-5 to 9], -0.675 [-9 to 18] and 0.542 mm [-5 to 13], respectively for groups A, B and P. The accuracy was significantly lower in group A than B (P=0.044) and group P (P=0.038). The Pearson correlation coefficient for CAOS and EOS measurements was 0.189, 0.701 and 0.891 for leg length and 0.668, 0.202 and 0.680 for offset, for groups A, B and P, respectively. No difference between groups were observed relative to the leg length objectives being achieved within ±2 mm (P=0.61) and ±5 mm (P=0.314). There were no differences in terms of the number of CAOS failures: three in group A, one in group B and three in group P (P=0.06). CONCLUSION: The Praxim™ and Brainlab™ CAOS systems had similar accuracy for leg length measurements, and both were better than the Amplitude™ system. Only the Praxim™ had an error of less than 0.6mm. All the CAOS systems had values less than 1mm, which is considered excellent. LEVEL OF EVIDENCE: Level IV, retrospective 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. Cohen's 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.

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.

Anatomical study of the blood supply of the coxal bone: radiological and clinical application.

The aim of this work was to study the arterial blood supply of the coxal bone in order to optimize radiological embolization and to minimize the risk of postoperative osteonecrosis. Ten fresh cadavers were dissected after intra-arterial injection of colored resin. All the collateral vessels running to this bone were described and counted. On 25 dry bones, the vascular foramina were measured with the aid of a millimetric gauge and a vascular map was created. The posterior part of the ilium appears to be twice as well vascularized as the anterior part. Fractures of the posterior arch of the pelvis are theoretically more hemorrhagic. The presence of the iliolumbar artery in contact with the sacroiliac joint increases the risk with open book or shearing fractures. The artery of the ischium, a collateral of the pudendal artery, supplies the posterior and lateral parts of the acetabulum and the artery of the roof of the acetabulum, its superior and lateral parts. The branches of the anterior and posterior divisions of the obturator artery supply the superior part of the surroundings of the obturator foramen and the antero-inferior and postero-inferior parts of the acetabulum. The Kocher approach may injure the artery of the ischium. Letournel's extended lateral approach and Mears' triradiate approach may injure the artery of the ischium and the artery of the roof of the acetabulum. The risk of osteonecrosis appears to be theoretically increased if one adds an endopelvic approach. The anterior approach to the acetabulum appears to be that which theoretically leads to the least devascularization. The French version of this article is available in the form of electronic supplementary material and can be obtained by using the Springer Link server located at http://dx.doi.org/10.1007/s00276-002-0029-2.