Does two dimensional templating allow for the use of reduced-size ancillaries in total hip arthroplasty?

PURPOSE: Rising costs in healthcare for total hip arthroplasty (THA) mean that new solutions must be considered, such as the use of single-use ancillaries (SUA). The goal of this study was to assess the accuracy of 2D templating in primary THA for the use of reduced-size SUA. Our hypothesis was that the accuracy of 2D templating in primary THA would be higher than 95%, give or take two sizes. METHOD: This single-centre prospective study included all primary THAs performed over two years. Templating was carried out using 2D templating on anteroposterior pelvic X-rays. The template sizes were compared to the implant sizes. The primary endpoint was the rate of coincidence between digitally templated estimates and the actual implant sizes. The secondary endpoint was the difference of accuracy based on patient parameters. RESULTS: We analysed 512 cases of THA. Accuracy within two sizes was 96.9% for acetabular implants and 98.5% for femoral implants. Accuracy was below the 95% threshold only in patients under 55 and over 85 years old. A BMI above 30.0 kg/m2 significantly reduced accuracy but did not fall below the 95% threshold. The operated hip, the type of implant, and the operative indication did not significantly influence templating accuracy. CONCLUSION: Using reduced-size SUA with five rasps and five reamers depending on template sizes means that THA can be performed in more than 95% of cases allowing the use of compact single use ancillaries.

Precise characterization of a corridor-shaped structure in Khufu's Pyramid by observation of cosmic-ray muons.

Khufu's Pyramid is one of the largest archaeological monument all over the world, which still holds many mysteries. In 2016 and 2017, the ScanPyramids team reported on several discoveries of previously unknown voids by cosmic-ray muon radiography that is a non-destructive technique ideal for the investigation of large-scale structures. Among these discoveries, a corridor-shaped structure has been observed behind the so-called Chevron zone on the North face, with a length of at least 5 meters. A dedicated study of this structure was thus necessary to better understand its function in relation with the enigmatic architectural role of this Chevron. Here we report on new measurements of excellent sensitivity obtained with nuclear emulsion films from Nagoya University and gaseous detectors from CEA, revealing a structure of about 9 m length with a transverse section of about 2.0 m by 2.0 m.

Clinical and radiological outcomes of internal fixation of complex talar neck and body fractures with locking plates through a dual approach.

INTRODUCTION: Talar fractures are rare and surgical treatment has not been standardized. The literature is rather poor on preserving talar vascularization in single or dual approaches. A dual approach allows better exposure and should limit devascularization. Locking plates are one of the modern solutions for challenging comminuted fractures. The aim of this study was to determine clinical and radiological outcomes in complex talar fracture (CTF) of the neck and body, fixed by locking plates through a dual approach with at least one locking plate. HYPOTHESIS: Locking-plate fixation of CTF through a dual approach leads to good clinical outcome. MATERIAL AND METHODS: A single-center retrospective study included 12 cases of CTF treated between January 2007 and May 2019. 3D CT was systematically performed to plan surgery. A dual approach and at least one locking plate were used for fixation. Clinical outcome was evaluated on AOFAS score. Reduction quality and correlation to clinical results were evaluated, reduction with<2mm joint step being considered satisfactory. Consolidation rate and occurrence of avascular necrosis of the talus (ANT), post-traumatic arthritis (PTA) and postoperative complications were analyzed. RESULTS: Mean follow-up was 27 months (range, 15-47). Mean AOFAS score was 70±18 (range, 30-97). Inframillimetric reduction was achieved in 67% of cases, without significant correlation with clinical results. The consolidation rate was 91.6%, ANT rate 18.2% and PTA rate 45.5%. One patient presented septic osteoarthritis secondary to scar necrosis. CONCLUSION: Locking plate fixation of CTF through a dual approach provided acceptable clinical outcomes. LEVEL OF EVIDENCE: IV; retrospective study.

Intramedullary nailing for adult open tibial shaft fracture. An 85-case series.

INTRODUCTION: Treatment of open tibial shaft fracture is controversial due to the risk of infection. We assessed results in a continuous series of open tibial shaft fractures treated by primary intramedullary nailing. HYPOTHESIS: Factors can be determined for non-union and onset of infection following primary intramedullary nailing in open tibial shaft fracture. PATIENTS AND METHOD: A retrospective study assessed open tibial shaft fractures treated by primary intramedullary nailing between January 2007 and December 2013. Fractures were classified on the AO and Gustilo classifications. Infection rates and time to union were compared. RESULTS: Eighty-five patients (85 fractures) were included: 13 Gustilo type I, 43 type II, 19 type III-A and 10 type III-B. Eight patients had infection (9%). Healing and union were obtained after nail exchange and reaming in 5 cases, and after bone transport in 2. One patient showed non-union at last follow-up. Infection risk did not correlate with Gustilo (p=0.55) or AO type (p=0.69). The interval between trauma and wound debridement was significantly longer in infected patients (p=0.048). Eighty-three fractures (97.6%) healed, at a mean 6.9±6.1 months (range, 2-40). Non-union was associated with AO type (p=0.04), and showed a non-significant association with Gustilo type (p=0.06). DISCUSSION: Time to treatment was the only factor influencing risk of infection. Non-union was related to AO comminution grade. Primary intramedullary nailing seemed reliable if treatment was early, with rigorous debridement. The advantages then are early resumption of weight-bearing and low patient burden. LEVEL OF EVIDENCE: V, retrospective study.

Characterization of wear debris released from alumina-on-alumina hip prostheses: Analysis of retrieved femoral heads and peri-prosthetic tissues.

We analyzed by SEM three alumina-on-alumina femoral heads obtained from three patients who underwent revision for an aseptic loosening of the acetabular component. In parallel, the peri-prosthetic tissues were analyzed histologically in search of wear debris coming from the ceramic. Stripe wears, abrasive streaks, craters, and areas with extensive biomaterial removal were evidenced on the three femoral heads by SEM. In the altered area, the structure of the ceramic composed of minute polyhedric grains packed together was evidenced. In the peri-prosthetic tissues, the alumina particles were present in different forms: larges particles appeared transparent and birefringent, small particles engulfed by the macrophages had a light brown tint and were not birefringent. Large particles corresponded to the grains observed by SEM. EDS microanalysis confirmed the presence of aluminum oxide in these particles. Alumina debris are difficult to identify microscopically due to their pleomorphism.

Discovery of a big void in Khufu's Pyramid by observation of cosmic-ray muons.

The Great Pyramid, or Khufu's Pyramid, was built on the Giza plateau in Egypt during the fourth dynasty by the pharaoh Khufu (Cheops), who reigned from 2509 bc to 2483 bc. Despite being one of the oldest and largest monuments on Earth, there is no consensus about how it was built. To understand its internal structure better, we imaged the pyramid using muons, which are by-products of cosmic rays that are only partially absorbed by stone. The resulting cosmic-ray muon radiography allows us to visualize the known and any unknown voids in the pyramid in a non-invasive way. Here we report the discovery of a large void (with a cross-section similar to that of the Grand Gallery and a minimum length of 30 metres) situated above the Grand Gallery. This constitutes the first major inner structure found in the Great Pyramid since the nineteenth century. The void, named ScanPyramids' Big Void, was first observed with nuclear emulsion films installed in the Queen's chamber, then confirmed with scintillator hodoscopes set up in the same chamber and finally re-confirmed with gas detectors outside the pyramid. This large void has therefore been detected with high confidence by three different muon detection technologies and three independent analyses. These results constitute a breakthrough for the understanding of the internal structure of Khufu's Pyramid. Although there is currently no information about the intended purpose of this void, these findings show how modern particle physics can shed new light on the world's archaeological heritage.

Impact of preoperative continuous femoral blockades on morphine consumption and morphine side effects in hip-fracture patients: A randomized, placebo-controlled study.

BACKGROUND: Upon arrival at the emergency department, hip-fracture pain relief is usually carried out via systemic opioids. Continuous nerve blocks are efficient in the postoperative period, but have not been evaluated preoperatively. This study compared the reduction in morphine consumption and related side effects of a continuous femoral block with a single shot block in hip-fracture patients. METHODS: Hip-fracture patients admitted to the emergency department received a femoral nerve catheter, with a single lidocaine injection. They were then randomized to ropivacaine (group R) or saline continuous infusion (placebo, group P) in a double-blind manner. Morphine consumption and side effects were prospectively collected until the 24th postoperative hour. RESULTS: Sixty patients were included and 55 analyzed. There were no significant differences between the 2 groups regarding fracture types, delay before surgery (median [Q1-Q3]: 21.3 [14.5-29.4] versus 20.8 [15.7-36.2] hours for groups R and P, respectively; P=0.87) and catheter duration (47.5 [39.8-52.4] versus 42.5 [32.1-50.5] hours, P=0.29). Total morphine consumption was not significantly decreased in group R (5 [0-14] versus 8 [4.5-11] mg, P=0.3) and pain scores were similar (mean±SD; VAS 29±15/100 versus 33±13, P=0.3). We observed a significant reduction in morphine adverse effects (31% versus 69% for groups R and P, respectively; P<0.01), mainly nausea (31% versus 59%, P=0.03). One morphine side effect could be avoided for every 5 patients treated. CONCLUSION: Preoperative continuous femoral blockades using ropivacaine reduce morphine side effects (mainly nausea) in hip-fracture patients without reducing morphine consumption.

Aluminum and iron can be deposited in the calcified matrix of bone exostoses.

Exostosis (or osteochondroma) is the most common benign bone tumor encountered in children and adults. Exostoses may occur as solitary or multiple tumors (in the autosomal syndromes of hereditary multiple exostoses). Exostoses are composed of cortical and medullary bone covered by an overlying hyaline cartilage cap. We have searched iron (Fe) and aluminum (Al) in the matrix of cortical and trabecular bone of 30 patients with exostosis. Al(3+) and Fe(3+) are two cations which can substitute calcium in the hydroxyapatite crystals of the bone matrix. The bone samples were removed surgically and were studied undecalcified. Perls' Prussian blue staining (for Fe) and solochrome azurine B (for Al) were used on the histological sections of the tumors. Al(3+) was detected histochemically in 21/30 patients as linear bands deposited by the osteoblasts. Fe(3+) was detected in 10 out of these 21 patients as linear bands in the same locations. Fe(3+) and Al(3+) were not identified in the bone matrix of a control group of 20 osteoporotic patients. Energy X-ray Dispersive Spectrometry failed to identify Fe and Al in bone of these tumors due to the low sensitivity of the method. Wavelength Dispersive Spectrometry identified them but the concentrations were very low. Histochemistry appears a very sensitive method for Fe(3+) and Al(3+) in bone.The presence of these two metals in the exostoses advocates for a disturbed metabolism of osteoblasts which can deposit these metals into the bone matrix, similar to which is observed in case of hemochromatosis with Fe(3+).