Background:
Residual rotatory knee laxity at midterm follow-up after isolated anterior cruciate ligament reconstruction (ACLR) versus ACLR with lateral extra-articular tenodesis (LET) remains an ...issue.
Purpose/Hypothesis:
To evaluate the outcomes of ACLR with or without additional LET at a minimum 2-year follow-up in patients with preoperative high-grade pivot shift (PS). Our hypothesis was that the addition of LET would decrease the risk of secondary meniscal injury and the presence of residual high-grade PS at follow-up.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
A retrospective analysis performed at 3 sports medicine centers identified 266 study patients; all had a high-grade PS (grade 2 or 3) preoperatively and underwent isolated ACLR with or without LET. Four different ACLR techniques were used: single-strand quadrupled semitendinosus (ST4) ACLR without LET (ST4 group; n = 55), ST4 with anatomic LET (ST4+LET group; n = 77), bone–patellar tendon and modified Lemaire LET (BTB+LET group; n = 43), and quadriceps tendon and modified Lemaire LET (QT+LET group; n = 91). At follow-up, we evaluated for the presence of high-grade (grade ≥2) PS. Preoperative meniscal tears and their treatment were recorded.
Results:
Overall, 185 (69.5%) patients had at least 1 meniscal tear at index surgery. The mean follow-up period was 44.3 months; 47 (17.7%) patients had a new meniscal tear and 64 (24%) patients had a high-grade PS at follow-up. Compared with meniscal repair, significant predictors for high-grade PS at follow-up were meniscectomy (odds ratio OR = 2.65 95% CI, 1.19-5.63; P = .02) and nonrepair of preoperative meniscal tear (OR = 3.26 95% CI, 1.27-9.43; P = .007). The appearance of a new symptomatic meniscal tear was the strongest significant predictor of high-grade PS at follow-up (OR = 4.31 95% CI, 2.31-8.06; P < .001). No significant correlation was observed between the addition of LET and the presence of high-grade PS at follow-up.
Conclusion:
In the current study, 1 in 4 patients with high-grade PS before ACLR with or without LET was at risk of residual rotatory knee laxity at mean 44-month follow-up, regardless of the technique used. Repairing a pre-existing meniscal lesion was more effective than performing LET to decrease the presence of a high-grade PS at follow-up.
Purpose
The aim of our cadaveric study was to compare the mechanical properties of different parts of the quadriceps’ tendon in a load to failure analysis as compared to three other, and most common ...types of grafts that are used to perform ligament’s reconstruction.
Methods
Ten fresh-frozen cadavers (5 women, 5 men) were selected from our anatomical department. Mean age at death was 64 years (48–87 years). Tendons were harvested to prepare (1) different quadriceps tendon’s specimens: lateral portion (QTlat), medial portion superficial layer (QTMsup) and deep layer (QTMdeep) and central portion superficial (QTCsup) and deep layers (QTCdeep) (2) Patellar Tendon (PT), (3) Gracilis+Semi-Tendinosus specimens (GST). Specimens were stored at − 40 °C in a freezing solution. Specimens were securely attached to a dedicated loading platform, measurements were done using a validated software. Load to failure testing was then carried out. Young’s Elastic moduli, ultimate Stress (MPa) and Deformation (%) were analysed.
Results
The elastic moduli of the PT was significantly higher than all other grafts, all medial and central QT layers (superficial and deep) were significantly higher than its lateral part (QTlat). In terms of Ultimate Stress, all grafts were significantly greater than QTlat, PT and GST were significantly superior to QT central portions and to ITB but there did not differ with the medial portion of QT. ITB ultimate stress values were significantly higher than QTlat. The ultimate deformations of all grafts were similar.
Conclusions
This study provides reference values in in order to characterize different parts of the QT that presents anatomically and Mechanically with complex characteristics. Every Layer of Quadriceps Tendon’s Central and Medial Portion Offered Similar Mechanical Properties than Two Strand Hamstrings or Ilio-Tibial Band.
N-acetylglucosamine-based saccharides (chitosaccharides) are components of microbial cell walls and act as molecular signals during host-microbe interactions. In the legume plant Medicago truncatula, ...the perception of lipochitooligosaccharide signals produced by symbiotic rhizobia and arbuscular mycorrhizal fungi involves the Nod Factor Perception (NFP) lysin motif receptor-like protein and leads to the activation of the so-called common symbiotic pathway. In rice and Arabidopsis, lysin motif receptors are involved in the perception of chitooligosaccharides released by pathogenic fungi, resulting in the activation of plant immunity. Here we report the structural characterization of atypical chitosaccharides from the oomycete pathogen Aphanomyces euteiches, and their biological activity on the host Medicago truncatula. Using a combination of biochemical and biophysical approaches, we show that these chitosaccharides are linked to β-1,6-glucans, and contain a β-(1,3;1,4)-glucan backbone whose β-1,3-linked glucose units are substituted on their C-6 carbon by either glucose or N-acetylglucosamine residues. This is the first description of this type of structural motif in eukaryotic cell walls. Glucan-chitosaccharide fractions of A. euteiches induced the expression of defense marker genes in Medicago truncatula seedlings independently from the presence of a functional Nod Factor Perception protein. Furthermore, one of the glucan-chitosaccharide fractions elicited calcium oscillations in the nucleus of root cells. In contrast to the asymmetric oscillatory calcium spiking induced by symbiotic lipochitooligosaccharides, this response depends neither on the Nod Factor Perception protein nor on the common symbiotic pathway. These findings open new perspectives in oomycete cell wall biology and elicitor recognition and signaling in legumes.
Two-stage exchange revision total hip arthroplasty (THA) performed in case of periprosthetic joint infection (PJI) has been considered for many years as being the gold standard for the treatment of ...chronic infection. However, over the past decade, there have been concerns about its safety and its effectiveness. The purposes of our study were to investigate our practice, collecting the overall spacer complications, and then to analyze their risk factors.
We retrospectively included 125 patients with chronic hip PJI who underwent a staged THA revision performed between January 2013 and December 2019. All spacer complications were systematically collected, and risk factors were analyzed. Statistical evaluations were performed using the Student's
-test, Mann-Whitney U test, and Fisher's exact test.
Our staged exchange practice shows poor results, which means a 42% mechanical spacer failure rate, and a 20% recurrent infection rate over the two years average follow-up period. Moreover, we found a high rate of spacer dislocation (23%) and a low rate of spacer fracture (8%) compared to the previous literature. Our findings stress that the majority of spacer complications and failures is reflecting a population with high comorbid burden, highlighted by the American Society of Anesthesiology grade, Charlson Comorbidity Index, and Lee score associations, as well as the cardiac, pulmonary, kidney, or hepatic chronic conditions.
Our experience of a two-stage hip exchange revision noted important complication rates associated with high failure rates of polymethylmethacrylate spacers. These findings must be interpreted in the light of the patient's comorbidity profiles, as the elective population for staged exchange has an increasing comorbid burden leading to poor results. In order to provide better results for this specific population, our conclusion suggests that comparative strategy studies are required to improve our therapeutic indication. Cite this article:
2022;3(6):485-494.
It is estimated that surgical procedures account for 20%-30% of the greenhouse gases emissions from health-care systems. Total knee replacements (TKR) are one of the most frequently performed ...procedures in orthopaedics. The aim of this study was to identify and quantify the environmental impacts generated by TKRs, the factors that generate the most emissions, and those that can be easily modified.
To calculate the life cycle carbon footprint of a posterior stabilized cemented TKR performed in a single orthopaedic surgery department, 17 TKRs performed between October 12 and 20, 2020 by 4 senior surgeons were analysed. The analysis of the life cycle included the manufacture of the implant, from raw materials to distribution; the journey made by patients and staff; and the surgery including all consumables required to facilitate the procedure.
The overall life cycle carbon footprint of a single TKR was 190.5 kg of CO2. This consisted of 53.7 kg CO2 (28%) for the manufacture of the prosthesis, 50.9 kg CO2 (27%) for travel, 57.1 kg CO2 (30%) for surgery, and 28.8 kg CO2 (15%) for waste management. This is comparable to a New York-Detroit direct flight.
The production of a total knee prosthesis, throughout its life cycle, generates emissions with important consequences on the environment and therefore on our health. Although much data are currently missing to make precise estimates, and especially regarding benefits in terms of patient function and its impact on carbon emissions, these data serve as a starting point for other more detailed or comparative studies.
Purpose
The Pivot Shift (PS) test is a complex clinical sign that assesses the internal rotation and anterior tibial translation, which occurs abnormally in ACL deficient-knees. Because of the high ...inter-observer variability, different devices have been designed to characterize this complex movement in quantitative variables. The objective of this pilot study is to validate the reproducibility of intraoperative quantitative assessment of the PS with a smartphone accelerometer.
Methods
Twelve ACL-injured knees were included and compared with the contralateral uninjured side. The PS was measured by two independent observers utilizing a smartphone accelerometer and graded according to the IKDC classification. Measurements were taken preoperatively, intraoperatively and postoperatively. Intraoperative readings were taken during each stage of reconstruction or repair of meniscoligamentous lesions including meniscal lesions, ramp lesions, ACL reconstruction and lateral tenodesis. Reproducibility of the measurements were evaluated according to an intraclass correlation coefficient (ICC).
Results
The intra-observer reliability was good for the first examiner and excellent for the second examiner, with the ICC 0.89 0.67, 0.98
p
< 0,001 and ICC 0.97 0.91, 1.0
p
< 0,001 respectively. The inter-observer reliability was excellent between the two observers with the ICC 0.99 0.97, 1.0
p
< 0,001. The mean tibial acceleration measured 3.45 m.s
2
(SD = 1.71) preoperatively on the injured knees and 1.03 m.s
2
(SD = 0.36) on the healthy knees, demonstrating a significant difference following univariate analysis
p
< 0.001. Postoperatively, no significant difference was observed between healthy and reconstructed knees The magnitudes of tibial acceleration values were correlated with the PS IKDC grade.
Conclusion
The smartphone accelerometer is a reproducible device to quantitatively assess the internal rotation and anterior tibial translation during ACL reconstruction surgery. The measurements are influenced by the different surgical steps. Other larger cohort studies are needed to evaluate the specific impact of each step of the ACL reconstruction and meniscal repair on this measurement. An external validation using other technologies are needed to validate the reliability of this device to assess the PS test.
Level of evidence
Level IV, case series, pilot study.
Medial opening wedge high tibial osteotomy (OW-HTO) is an excellent surgical option for patients with varus knee osteoarthritis. This article presents a technique of performing a minimally invasive ...OW-HTO using a patient-specific cutting guide (PSCG). Preoperative 3-dimensional planning with computed tomography imaging is essential. The correction parameters, the final plate position, as well as the 3-dimensional position of the hinge as well as wedge are verified preoperatively before the PSCG is produced. After exposure with an oblique incision over the posteromedial tibia, the hamstring tendons are released for later re-attachment and the medial collateral ligament is released slightly. The PSCG is then used to perform the OW-HTO with protection of the posterior neurovascular structures by a retractor placed posterior to the medial collateral ligament. The final fixation of the osteotomy is achieved with a low-profile locking plate and a femoral head allograft wedge.
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Background:
Three main meniscal preservation methods have been used over the past decade: cryopreservation, freezing, and freezing with gamma irradiation.
Hypothesis:
All 3 preservation methods will ...result in similar biomechanical properties as defined by tensile and compression testing.
Study Design:
Controlled laboratory study.
Methods:
A total of 24 human lateral menisci were collected from patients who underwent total knee arthroplasty. Inclusion criteria were patients younger than 70 years with primary unilateral (medial) femorotibial knee osteoarthritis. Each meniscus was divided into 2 specimens cross-sectionally. One specimen was systematically cryopreserved and constituted the control (Cy; –140°C), and the other specimen was used for either the simple frozen group (Fr; –80°C) or the frozen+irradiated group (FrI; –80°C + 25-kGy irradiation). Compression and tensile tests were performed to analyze the elasticity modulus (Young modulus) in compression, the elasticity modulus in tension, the tensile force at failure, and the rupture profile of the tensile stress-strain curve.
Results:
A significant difference in the mean compression elasticity modulus was observed between the Cy and Fr groups (28.86 ± 0.77 vs 37.26 ± 1.08 MPa, respectively; P < .001) and between the Cy and FrI groups (28.86 ± 0.77 vs 45.92 ± 1.09 MPa, respectively; P < .001). A significant difference in the mean tensile elasticity modulus was also observed between the Cy and Fr groups (11.66 ± 0.97 vs 19.97 ± 1.37 MPa, respectively; P = .008) and between the Cy and FrI groups (11.66 ± 0.97 vs 45.25 ± 1.39 MPa, respectively; P < .001). There were no significant differences between the control and study groups in tensile force at failure. The analysis of the stress-strain curve revealed a slow-slope curve with a nonabrupt rupture (ductile material) for the Cy samples versus a clear rupture of the curve for the Fr and FrI samples (more fragile material).
Conclusion:
Cryopreservation allows for more elastic and less fragile tissue compared with simple freezing or freezing plus irradiation.
Clinical Relevance:
The study results exhibit the detrimental effect of simple freezing and freezing plus irradiation on human meniscal mechanical properties. If these effects occur in menisci prepared for allograft procedures, important differences could appear in the graft’s mechanical behavior and thus patient outcomes.
A pathosystem between Aphanomyces euteiches, the causal agent of pea root rot disease, and the model legume Medicago truncatula was developed to gain insights into mechanisms involved in resistance ...to this oomycete. The F83005.5 French accession and the A17-Jemalong reference line, susceptible and partially resistant, respectively, to A. euteiches, were selected for further cytological and genetic analyses. Microscopy analyses of thin root sections revealed that a major difference between the two inoculated lines occurred in the root stele, which remained pathogen free in A17. Striking features were observed in A17 roots only, including i) frequent pericycle cell divisions, ii) lignin deposition around the pericycle, and iii) accumulation of soluble phenolic compounds. Genetic analysis of resistance was performed on an F7 population of 139 recombinant inbred lines and identified a major quantitative trait locus (QTL) near the top of chromosome 3. A second study, with near-isogenic line responses to A. euteiches confirmed the role of this QTL in expression of resistance. Fine-mapping allowed the identification of a 135-kb sequenced genomic DNA region rich in proteasome-related genes. Most of these genes were shown to be induced only in inoculated A17. Novel mechanisms possibly involved in the observed partial resistance are proposed.
Background:
Inadequate deformity analysis and planning before high tibial osteotomy (HTO) may result in correction errors with unsatisfactory clinical results.
Indications:
The purpose of this ...article is to describe the deformity analysis and preoperative planning before HTO. This surgery is effective for young patients with compartmental mild knee osteoarthritis. A partial deformity analysis without considering the femoral or intra-articular deformity may lead to overcorrection or excessive joint line obliquity. Preoperative planning using the Miniaci method with manual or semiautomated digital measures may help to prevent these types of errors.
Technique Description:
Landmarks are used at the proximal femoral side, distal condyles, proximal tibial plateau, and talus borders to define angles automatically on PeekMed software. Fujisawa point is determined to be 50% of the length of the proximal tibia, and Miniaci method is performed after defining the weightbearing line. The method can be performed manually or semiautomatically with the software. In this last case, the optimal procedure to be done to correct the malalignment is proposed by the software which automatically does the opening of the osteotomy to match the desired weightbearing axis and displays the size of the wedge in millimeters.
Results:
The intraobserver and interobserver reproducibility were performed by 2 different analyses and 2 different observers. The precision of the measures was confirmed based on computed tomographic (CT) scan 3-dimensional measures defined as the gold standard. All the intraobserver and interobserver reproducibility correlation coefficients and precision were satisfactory compared with the gold standard. Hip-knee-ankle angle may vary because of weightbearing situations between CT and long-axis x-rays.
Discussion/Conclusion:
The interest of semiautomated software for angular value measurements is now well recognized, and the inclusion of anatomical landmarks allows accurate and reproducible angular value measurements. Automatic knee osteotomy planning analyzes the metaphyseal deformity of both the tibia and the femur, and the software suggests the optimal procedure with the degree of openness to obtain the desired mechanical axis without creating excessive joint line obliquity
Graphical Abstract
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