Excitonic Effects in Energy-Loss Spectra of Freestanding Graphene.

In this work, we perform electron energy-loss spectroscopy (EELS) of freestanding graphene with high energy and momentum resolution to disentangle the quasielastic scattering from the excitation gap of Dirac electrons close to the optical limit. We show the importance of many-body effects on electronic excitations at finite transferred momentum by comparing measured EELS to ab initio calculations at increasing levels of theory. Quasi-particle corrections and excitonic effects are addressed within the GW approximation and the Bethe-Salpeter equation, respectively. Both effects are essential in the description of the EEL spectra to obtain a quantitative agreement with experiments, with the position, dispersion, and shape of both the excitation gap and the π plasmon being significantly affected by excitonic effects.

Anterior Cruciate Ligament Revision Plus Lateral Extra-Articular Procedure Results in Superior Stability and Lower Failure Rates Than Does Isolated Anterior Cruciate Ligament Revision but Shows No Difference in Patient-Reported Outcomes or Return to Sports.

PURPOSE: To determine whether comparative clinical studies demonstrate significant advantages of revision anterior cruciate ligament reconstruction (RACLR) combined with a lateral extra-articular procedure (LEAP), with respect to graft rupture rates, knee stability, return to sport rates, and patient-reported outcome measures, compared with isolated RACLR. METHODS: A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews & Meta-Analyses Guidelines. A PubMed search was conducted using the key words "revision anterior cruciate ligament reconstruction" combined with any of the following additional terms, "lateral extra-articular tenodesis" OR "anterolateral ligament reconstruction" OR "Lemaire." All relevant comparative clinical studies were included. Key clinical data were extracted and evaluated. RESULTS: Eight comparative studies (seven Level III studies and a one Level IV study) were identified and included. Most studies reported more favorable outcomes with combined procedures with respect to failure rates (0%-13% following RACLR+LEAP, and 4.4%-21.4% following isolated RACLR), postoperative side-to-side anteroposterior laxity difference (1.3-3.9 mm following RACLR+LEAP and 1.8-5.9 mm following isolated RACLR), and high-grade pivot shift (0%-11.1% following RACLR+LEAP and 10.2%-23.8% in patients following isolated RACLR). There were no consistent differences between isolated and combined procedures with respect to return to sport or patient-reported outcome measures. CONCLUSIONS: This systematic review demonstrates that the addition of a LEAP to RACLR was associated with an advantage with respect to ACL graft failure rates and avoidance of high-grade postoperative knee laxity across almost all included studies. LEVEL OF EVIDENCE: IV, Systematic review of level III to IV studies.

Clinical Outcomes of Combined Anterior Cruciate Ligament Reconstruction and Lateral Extra-articular Tenodesis Procedures in Skeletally Immature Patients: A Systematic Review From the SANTI Study Group.

BACKGROUND: The treatment of anterior cruciate ligament (ACL) tears in the pediatric population has changed significantly in the past few decades. Pediatric patients who underwent ACL reconstruction (ACLR) have a high risk of rerupture of up to 32%. The addition of lateral extra-articular procedures [lateral extra-articular tenodesis (LET)], already shown to be effective in reducing the risk of rerupture in adults, may also be effective in pediatric patients. The purpose of this study was to systematically review the clinical outcomes of ACLR+LET tenodesis in pediatric patients. METHODS: Data were collected from Pubmed, MEDLINE, Cochrane, and Scopus Databases according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Studies reporting the clinical outcomes of ACLR+LET in the pediatric population using autograft, return to play, growth disturbances, failure rate, and surgical complications were included. RESULTS: A total of 5 studies comprising 381 pediatric patients were included. Three main surgical techniques with common features were used. The mean age of all pediatric patients in the included studies was 11.73 years (range, 5.6 to 16) with a mean follow-up of 50.1 months. The overall graft failure rate of the included studies was 4.65%. The return to play was 95.11%. The mean Lysholm score was 94.51 and the mean Pediatric International Knee Documentation Committee (Pedi-IKDC) was 93.39. In all, 1.9% of the patients had a coronal plane deformity and 0.8% had a limb length discrepancy. 4.6% of the patients had a contralateral ACL tear. CONCLUSIONS: A combined ACLR+LET in pediatric patients showed a graft failure ranging from 0% to 13.6% at a mean follow-up of 50.1 months. This low graft failure rate is consistent with ACLR+LET in adults. Further investigations are needed to validate these findings and the potential role of LET in reducing graft rupture rates in this population. LEVEL OF EVIDENCE: Level IV-systematic review of level IV studies.

Correlation between Risk Factors and Healing Times in Long Bone Nonunions Treated with Corticoperiosteal Flap from the Medial Femoral Condyle.

BACKGROUND: The rate of fracture nonunion varies depending on the anatomical site. Numerous procedures have been proposed to treat recalcitrant nonunions. The vascularized medial femoral condyle corticoperiosteal free flap (MFCCFF) is increasingly used in nonunions with small bone loss.The percentage of success of the MFCCFF is high but the factors involved in delayed bone healing or failure of this technique or the contraindications are not described in the literature.This multicentric study aims to identify and report the different factors involved in determining the time of bone healing in the treatment of atrophic nonunion of long bones with the vascularized medial MFCCFF. METHODS: All patients who underwent vascularized medial MFCCFF from January 2011 to December 2020 for the treatment of recalcitrant atrophic nonunions of long bones. Patients were reviewed at 2 and 6 weeks, and 3, 6, and 12 months postoperatively and evaluated by physical and radiographic examinations and patient-reported outcome measures. RESULTS: The final study population comprised 59 patients with a mean follow-up of 26.2 ± 7.6 months, a rate of bone healing of 94.9% with a mean radiographic bone healing time of 4.1 ± 1.3 months, and low morbidity of the donor site. Diabetes mellitus, a body mass index (BMI) ≥30 kg/m2, and ≥2 previous surgeries on the fracture site were factors predicting timing for bone healing at the multivariate analysis. CONCLUSION: This study demonstrates the MFCCFF as an effective and safe procedure for the treatment of the recalcitrant atrophic nonunion of long bones. An association was found between the lengthening of bone healing time and a high BMI, presence of ≥2 previous surgical interventions, and diabetes mellitus, indicating these comorbidities as risk factors (not absolute contraindications) for this microsurgical treatment. So, to our knowledge, the MFCCFF could be the first-choice treatment for atrophic nonunion of long bones.

Electronic-structure methods for materials design.

The accuracy and efficiency of electronic-structure methods to understand, predict and design the properties of materials has driven a new paradigm in research. Simulations can greatly accelerate the identification, characterization and optimization of materials, with this acceleration driven by continuous progress in theory, algorithms and hardware, and by adaptation of concepts and tools from computer science. Nevertheless, the capability to identify and characterize materials relies on the predictive accuracy of the underlying physical descriptions, and on the ability to capture the complexity of realistic systems. We provide here an overview of electronic-structure methods, of their application to the prediction of materials properties, and of the different strategies employed towards the broader goals of materials design and discovery.

Translation, cross-cultural adaptation, and validation of the Italian version of the anterior cruciate ligament-return to sport after injury (ACL-RSI) scale and its integration into the K-STARTS test.

BACKGROUND: The timing of a return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR) represents a major subject of debate in sports medicine practice. Recently, the Knee Santy Athletic Return to Sport (K-STARTS) composite test was validated. This consists of a battery of physical tests and a psychological evaluation using the anterior cruciate ligament-return to sport after injury scale (ACL-RSI). This study aimed to translate the ACL-RSI and K-STARTS from English to Italian and determine the scale's reliability and validity in an Italian context. METHODS: The translation and cultural adaptation process was performed according to the guidelines for the cross-cultural adaptation of self-report measures. The patients were asked to fill an anonymized online form created for this purpose that included the KOOS, the Lysholm, the IKDC-SKF, and the Italian translation of the ACL-RSI (ACL-RSI-It). After 1 week, the attendees were asked to repeat the ACL-RSI-It to investigate the test-retest reliability. RESULTS: The final study population comprised 115 patients who underwent ACLR, with a mean follow-up of 37.37 ± 26.56 months. The ACL-RSI-It showed axcellent internal consistency (Cronbach's α = 0.963), reliability (test-retest ICC = 0.966), and good construct validity (positive correlations with the other scales were above 75%). CONCLUSIONS: The ACL-RSI-It is valid, reliable, and comparable to the original English version of the questionnaire for Italian-speaking patients. It can be used to assess the psychological readiness of patients for a RTS after primary and unilateral ACLR, and can be integrated into the Italian K-STARTS test. LEVEL OF EVIDENCE: Level II.

The Segond's fracture and the anterolateral ligament.

The study of Mullins et al. reasonably explains how the Segond's fracture is probably the most frequent avulsion fracture of the tibia plateau, but it does not challenge the hypothesis of the existence of a discrete ligament (the ALL) strong enough to sometimes pull out its bony insertion as a result of a forced internal rotation and of an ACL failure.

Accuracy and Cost-Effectivenss of a Novel Method for Alpha Defensins Measurement in the Diagnosis of Periprosthetic Joint Infections.

BACKGROUND: Two methods for detecting synovial fluids alpha defensins are available: the enzyme-linked immunosorbent assay and the lateral flow test. For both, the proper role and accuracy remain uncertain. The purpose of this study was to assess the accuracy of the matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) for alpha defensin detection in synovial fluids of patients with total knee arthroplasty/total hip arthroplasty failures. The hypothesis was that the alpha defensin measurement through MALDI-TOF MS assay could be a high sensitive and specific test for periprosthetic joint infections (PJI) diagnosis as compared with Musculoskeletal Infection Society (MSIS) criteria. METHODS: The study included 138 patients. The 2018 MSIS criteria were used to diagnose PJIs. Synovial fluids were assessed for routinely synovial fluid tests and alpha defensin measurement through MALDI-TOF MS. Sensitivity, specificity, overall diagnostic accuracy, positive and negative predictive values, receiver operator curves, and area under the curve were calculated. RESULTS: As per the 2018 MSIS criteria, 59 PJIs (43%) and 79 aseptic failures (57%) were diagnosed. The MALDI-TOF MS assay showed an overall accuracy of 94.9%. The sensitivity was 93%, the specificity was 96%, the positive predictive value was 95%, and the negative predictive value was 95%. Receiver operator curves analysis demonstrates an area under the curve of 0.95 (P < .001). CONCLUSION: The MALDI-TOF MS assay showed high sensitivity and specificity for alpha defensin detection in case of total knee arthroplasty/total hip arthroplasty failures. The advantages of the technology, such as the few milliliters of sample needed, the rapidity of obtaining results, and the cost-effectiveness of the procedure could make the MALDI-TOF MS alpha defensin assay a useful and widespread test in clinical practice.

The Accuracy of Patient-Specific Instrumentation with Laser Guidance in a Dynamic Total Hip Arthroplasty: A Radiological Evaluation.

The functional positioning of components in a total hip arthroplasty (THA) and its relationship with individual lumbopelvic kinematics and a patient's anatomy are being extensively studied. Patient-specific kinematic planning could be a game-changer; however, it should be accurately delivered intraoperatively. The main purpose of this study was to verify the reliability and accuracy of a patient-specific instrumentation (PSI) and laser-guided technique to replicate preoperative dynamic planning. Thirty-six patients were prospectively enrolled and received dynamic hip preoperative planning based on three functional lateral spinopelvic X-rays and a low dose CT scan. Three-dimensional (3D) printed PSI guides and laser-guided instrumentation were used intraoperatively. The orientation of the components, osteotomy level and change in hip length and offset were measured on postoperative CT scans and compared with the planned preoperative values. The length of surgery was compared with that of a matched group of thirty-six patients who underwent a conventional THA. The mean absolute deviation from the planned inclination and anteversion was 3.9° and 4.4°, respectively. In 92% of cases, both the inclination and anteversion were within +/- 10° of the planned values. Regarding the osteotomy level, offset change and limb length change, the mean deviation was, respectively, 1.6 mm, 2.6 mm and 2 mm. No statistically significant difference was detected when comparing the planned values with the achieved values. The mean surgical time was 71.4 min in the PSI group and 60.4 min in the conventional THA group (p < 0.05). Patient-specific and laser-guided instrumentation is safe and accurately reproduces dynamic planning in terms of the orientation of the components, osteotomy level, leg length and offset. Moreover, the increase in surgical time is negligible.

Measurement technique for posterior tibial slope on radiographs can affect its relationship to the risk of anterior cruciate ligament rupture.

PURPOSE: The purpose of this study was to determine the most reliable radiographic measurement method to evaluate PTS as a risk factor for ACL reconstruction failure. METHODS: Patients who underwent ACL reconstruction or ACL revision reconstruction between January 2009 and December 2014 by a single surgeon were included. Fifty-two consecutive patients who underwent ACL revision reconstruction were compared to a random selection of 52 patients who underwent primary ACL reconstruction and a control group of 52 patients without ACL injury. ACL reconstruction was performed using either ipsilateral (primary) or contralateral (revision) quadrupled hamstring autograft. Lateral knee radiographs were evaluated using three methods: (1) longitudinal axis, (2) anterior tibial cortex axis, and (3) posterior tibial cortex. RESULTS: A significant difference was found between subjects who underwent ACL reconstruction and control knees (6.79° vs. 5.31°, p = 0.046) using the posterior tibial cortex method. No other statistical significance was found between groups. A multiple linear regression analysis found that the PTS as measured by any method was not affected by the patient's age, sex, height, weight, and BMI. All methods of measurement for PTS demonstrated excellent (ICC > 0.90) intra-rater and inter-rater reliability, but only the posterior tibial cortex method maintained excellent intra-rater and inter-rater reliability (ICC > 0.90) when evaluating patients with ACL revision reconstruction. CONCLUSIONS: The posterior tibial cortex measurement is the most reliable method for analyzing the PTS on lateral knee radiographs in patients undergoing ACL revision reconstruction.

Bilateral Post Traumatic Myositis Ossificans of Adductor Longus in a Young Soccer Player: A Case Report and Literature Review.

ABSTRACT: Myositis ossificans traumatica (MOT) is a self-limiting and self-resolving pathology. In most cases, conservative treatment is chosen as the first step. Surgical treatment is reserved for cases of failure of conservative treatment with persistence of pain and mass. The case presented concerns an 18-year-old soccer player suffering from bilateral adductor longus (AL) MOT results following two different sports injuries. The patient reports the appearance of swelling and palpable mass at the proximal and medial region of the thigh, about 2 cm from the pubic symphysis, along the course of the adductor magnus. The radiological investigation showed the presence of a calcification along the course of the right and left AL muscles. Surgical treatment was considered for the right thigh injury, being symptomatic 1 year after the onset and refractory to other treatments. At 3 months of follow-up, the patient was asymptomatic and completed the rehabilitation program for the recovery of muscle strength and range of motion (ROM). In cases where MOT manifests with resistant pain, ROM restriction and daily activity reduction, surgical excision is the preferred option.

Detection of α-defensin in synovial fluids by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry as an innovative and cost-effective assay for improved definition of periprosthetic joint infections.

RATIONALE: Detection of α-defensins in synovial fluid is gaining more and more interest in the field of correct diagnosis of periprosthetic joint infections (PJIs). At present, they can be assessed by a quantitative enzyme-linked immunosorbent assay which is expensive and time-consuming and by a qualitative lateral flow immunoassay which is rapid but quite expensive and whose clinical sensitivity is debated. Thus, developing an alternative rapid, accurate, and low-cost assay for α-defensins is important to make α-defensins actionable as novel key clinical markers. METHODS: Synovial fluid (SF) samples were obtained from 18 patients undergoing revision of primary joint arthroplasty. Of these, eight met the 2013 Musculoskeletal Infection Society (MSIS) criteria for PJIs, the remaining were classified as aseptic failure. Microbiological analysis and Synovasure assays were carried out on all samples. Sample preparation and the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) settings were adjusted to detect human neutrophil peptide (HNP)-1, -2 and -3 and to obtain optimal results in term of sensitivity and stability. RESULTS: MALDI-TOF MS was able to detect HNPs in SF from septic patients. No signals for HNPs were detected in SF from aseptic failure. The limits of detection (LOD) were 2.5 and 1.25 µg/mL for HNP-2 and HNP-1, respectively. The turnaround time of the analysis is 20 min, and SF samples are stable at -20°C for up to 3 days. Assay sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were 100% for all parameters. On the same SF samples, the Synovasure assay showed lower sensitivity specificity, and PPV and NPV of 87.5%, 90%, 87.5% and 90%, respectively. Microbiological analysis of SF confirmed the presence of bacteria only in SF MSIS-positive patients. CONCLUSIONS: The reported MALDI-TOF MS assay was able to detect and differentiate HNPs in SF samples and showed a slightly better diagnostic accuracy than the Synovasure assay.

Surface chemistry effects on work function, ionization potential and electronic affinity of Si(100), Ge(100) surfaces and SiGe heterostructures.

We combine density functional theory and many body perturbation theory to investigate the electronic properties of Si(100) and Ge(100) surfaces terminated with halogen atoms (-I, -Br, -Cl, -F) and other chemical functionalizations (-H, -OH, -CH3) addressing the absolute values of their work function, electronic affinity and ionization potential. Our results point out that electronic properties of functionalized surfaces strongly depend on the chemisorbed species and much less on the surface crystal orientation. The presence of halogens at the surface always leads to an increment of the work function, ionization potential and electronic affinity with respect to fully hydrogenated surfaces. On the contrary, the presence of polar -OH and -CH3 groups at the surface leads to a reduction of the aforementioned quantities with respect to the H-terminated system. Starting from the work functions calculated for the Si and Ge passivated surfaces, we apply a simple model to estimate the properties of functionalized SiGe surfaces. The possibility of modulating the work function by changing the chemisorbed species and composition is predicted. The effects induced by different terminations on the band energy line-up profile of SiGe surfaces are then analyzed. Interestingly, our calculations predict a type-II band offset for the H-terminated systems and a type-I band offset for the other cases.

Empty electron states in cobalt-intercalated graphene.

The dispersion of the electronic states of epitaxial graphene (Gr) depends significantly on the strength of the bonding with the underlying substrate. We report on empty electron states in cobalt-intercalated Gr grown on Ir(111), studied by angle-resolved inverse photoemission spectroscopy and x-ray absorption spectroscopy, complemented with density functional theory calculations. The weakly bonded Gr on Ir preserves the peculiar spectroscopic features of the Gr band structure, and the empty spectral densities are almost unperturbed. Upon intercalation of a Co layer, the electronic response of the interface changes, with an intermixing of the Gr π* bands and Co d states, which breaks the symmetry of π/σ states, and a downshift of the upper part of the Gr Dirac cone. Similarly, the image potential of Ir(111) is unaltered by the Gr layer, while a downward shift is induced upon Co intercalation, as unveiled by the image state energy dispersion mapped in a large region of the surface Brillouin zone.

Quantum ESPRESSO toward the exascale.

Quantum ESPRESSO is an open-source distribution of computer codes for quantum-mechanical materials modeling, based on density-functional theory, pseudopotentials, and plane waves, and renowned for its performance on a wide range of hardware architectures, from laptops to massively parallel computers, as well as for the breadth of its applications. In this paper, we present a motivation and brief review of the ongoing effort to port Quantum ESPRESSO onto heterogeneous architectures based on hardware accelerators, which will overcome the energy constraints that are currently hindering the way toward exascale computing.

Rupture of the Patellar Tendon After Platelet-Rich Plasma Treatment: A Case Report.

INTRODUCTION: Rupture of the patellar tendon is becoming more and more frequent, even in sports activities overloading the extensor mechanism of the knee. Platelet-rich plasma (PRP) treatment has been recently introduced in treatment for several knee- and sport-related injuries including muscle strain cartilage defect and tendinopathies. The aim of this case report is to present a case of rupture of the patellar tendon occurred after injections of PRP. CASE REPORT: A case of a 40-year-old male soccer player sustaining a patellar tendon rupture after a series of 4 PRP injections. At surgery, a complete rupture in the middle of the patellar tendon was found, with severe degenerative changes of the tendon tissue. This case questions the actual efficacy and safety of PRP in severe degenerative tendinopathies.

Comorbidities rather than age affect medium-term outcome in octogenarian patients after total knee arthroplasty.

PURPOSE: As the population ages, it is important to determine whether total knee arthroplasties (TKA)s are safe and beneficial in the octogenarian population. The aims of the present study were: (1) to assess the effect of comorbidities and age on the incidence of postoperative complications following TKA and (2) to evaluate the mid-term outcome of octogenarian patients. METHODS: A retrospective matched-paired analysis by gender, BMI and duration of follow-up was conducted on 206 patients older than 80 years and younger than 75 years between 2009 and 2016, undergoing primary TKA. The mean follow-up was 5 years. Outcome measures including Oxford Knee Score (OKS), Knee Society Score (KSS), Knee Society Function Score (KSFS), postoperative complications, length of stay (LOS) and survivorship were analysed. The association between complications and comorbidities was assessed using multivariable logistic regression after adjusting for age, Deyo-Charlson Comorbidity Index (D-CCI) and the American Society of Anesthesiologist's (ASA) physical status classification. RESULTS: In the multivariable models, D-CCI class is an independent predictor for postoperative cardiac complications, delirium and transfusion rate (OR ranging from 1.2 to 69.5 in respect to D-CCI reference class 0). Being ≥ 80 years old was associated with an increased risk of transfusion (OR 3.4; 95% CI 1.7-6.8) and 1.7-day increase in LOS (p < 0.001). Both groups showed significant improvement in postoperative knee scores following TKA. CONCLUSION: Octogenarians experienced good clinical results when compared to their younger counterparts. Comorbidities, rather than age itself, are responsible for the increase in postoperative morbidity. Preoperative risk assessment has to be optimized in order to reduce complications.

Heat loss in sleeping garden warblers (Sylvia borin) during migration.

For small songbirds, energy is often a limiting factor during migration and, for this reason, they are forced to alternate nocturnal flights with stopovers to rest and replenish energy stores. Stopover duration has a key role for a successful migration and may have an important impact on fitness. Thus, migrants need to optimize their energy consumption at this stage to reduce their permanence at the site. A recent study has shown that lean individuals reduce their metabolic rate when tucking the head in the feathers during sleep. The underlying mechanism is very likely a reduction in conductance, but the thermoregulatory benefit of the increased insulation has never been quantified yet. Here, we compared heat loss in individual migratory birds while sleeping in different postures. Using a thermal camera and a within-individual approach, we estimated that Garden Warblers can reduce their rate of heat loss by 54% by sleeping with the head tucked in the feathers. This energy saving has a relevant impact on the individual's energy balance because it can account for up to 8.69% of daily energy expenditure during stopover. Our study provides novel and important information to understand the fundamental role of thermoregulatory strategies on bird's energy management.

Could the tendon degeneration and the fatty infiltration of the gluteus medius affect clinical outcome in total hip arthroplasty?

PURPOSE: The aim of this prospective study was to perform a clinical and radiologic evaluation of patients undergoing total hip arthroplasty (THA). The hypothesis is that there is a correlation between the pre-operative degeneration state of the gluteal muscle-tendinous unit and the clinical outcome in terms of functional recovery. METHODS: Fifty-five patients have met inclusion criteria. All patients included in the sample were subjected to clinical evaluation. The ultrasound examination of the patients of the study was conducted and the following parameters were assessed: Thickness in mm of the gluteus medius tendon; Quality of the gluteus medius tendon; and Trophy and muscular composition. RESULTS: The degree of degeneration of the pre-operative tendon shows a negative statistical correlation with all the pre- and post-operative clinical scales, but presents statistical significance (p < 0.05) only with the post-operative Harris, the post-operative Oxford, the Harris and HOOS-modified post-operative, lameness, and Trendelenburg; it correlates positively with the quality of the macroscopic tendon detected intra-operatively, the degree of the pre-operative contralateral tendon, and the operated and contralateral pre-operative muscle (p < 0.05). The degree of fatty degeneration of the pre-operatively operated muscle correlates negatively (p < 0.05) with all pre- and post-operative clinical scales except for the pre-operative WOMAC and HOOS modified, with the lameness and the Trendelenburg sign; it correlates positively (p < 0.05) with age, the quality of the macroscopic tendon detected intra-operatively, degree of tendon degeneration, fatty infiltration of the contralateral pre- and post-operative muscle and of the post-operative operated muscle. CONCLUSION: Tendon degeneration and fatty infiltration of the gluteus medius muscle appeared to be determinants of the post-operative persistence of lameness and Trendelenburg sign positivity in patients undergoing hip arthroplasty.

The healing potential of an acutely repaired ACL: a sequential MRI study.

BACKGROUND: Recently, there has been renewed interest in primary anterior cruciate ligament (ACL) repair. The aim of this study is to report early clinical and radiological results of a consecutive series of acute ACL tears treated with arthroscopic primary ACL repair within 14 days from injury. PATIENTS AND METHODS: A consecutive series of patients with acute ACL tears were prospectively included in the study. Based on MRI appearance, ACL tears were classified into five types, and tissue quality was graded as good, fair, and poor. Patients with type I, II, and III tears and at least 50% of ACL tibial remnant intact with good tissue quality were ultimately included. Clinical outcomes were measured using the Tegner Lysholm Knee Scoring Scale (TLKSS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), subjective and objective International Knee Documentation Committee (IKDC) scores, and KT-1000. Patients were also followed up with MRI evaluations at 1, 3, and 6 months postoperatively. ACL appearance was graded based on morphology (normal or abnormal) and signal intensity (isointense, intermediate, and hyperintense). RESULTS: The mean TLKSS was 98.1, the mean subjective IKDC was 97.6, and the mean KOOS was 98.2. The objective IKDC score was A in eight of ten patients and B in two patients. KT-1000 measurements showed a maximum manual side-to-side difference of less than 2 mm in eight of ten patients, whereas two patients showed a difference of 3 mm. The morphology of the repaired ACL was normal (grade 1) at 1 month follow-up in ten of ten cases, and this appearance persisted at 3 and 6 months postoperatively. The signal intensity at 1 month postoperatively was graded as isointense (grade 1) in four of ten patients, intermediate (grade 2) in five of ten patients, and hyperintense (grade 3) in one of ten patients. At both 3 and 6 months postoperatively, the signal intensity was graded as isointense (grade 1) in nine of ten patients and intermediate (grade 2) in one of ten patients. CONCLUSIONS: Arthroscopic primary ACL repair performed acutely in a carefully selected group of patients with proximal ACL tears and good tissue quality showed good early clinical and radiological results. LEVEL OF EVIDENCE: Level 4.