Comparison of the Effects of Cognitive Dual-Task and Single-Task Balance Exercises on Static Balance among People with Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial.

Objectives: The anterior cruciate ligament (ACL) reconstruction surgery improves mechanical stability; however, functional stability remains impaired. Balance exercises can help improve functional stability. The effect of cognitive dual-task balance exercises has not been studied in people with ACL reconstruction surgery; therefore, this study aimed to compare the effect of cognitive dual-task and single-task balance exercises on the static balance indices in these individuals. Methods: This study was a randomized clinical trial. After a period of conventional physiotherapy and applying inclusion criteria, 28 patients with ACL reconstruction surgery were randomly divided into two groups of cognitive dual-task and single-task balance exercises. Each group received the relevant exercises for four weeks, three times a week, with each session lasting 20 min. Center of pressure variables, including mean displacement in anterior-posterior and medial-lateral directions, total path length, mean velocity of displacement, root mean square of displacement and velocity, and the elliptical area, were measured using the FDM pressure platform before and after the interventions as the primary outcomes. Knee Injury and Osteoarthritis Outcome Score (KOOS) scale was completed by the participants before and after the interventions. Results: The measured static balance variables and KOOS subscales had significant differences before and after intervention in both groups (P<0.05); however, no statistically significant difference was observed in these variables between the two groups. There was no significant correlation between KOOS subscales and measured static balance variables. Conclusion: Both cognitive dual-task and single-task balance exercises improved the indicators related to static balance and the level of functional disability of the knee. However, cognitive dual-task balance exercises had no superiority over single-task balance exercises in ACL-reconstructed individuals.

Photoemission electron microscopy for connectomics.

Detailing the physical basis of neural circuits with large-volume serial electron microscopy (EM), 'connectomics', has emerged as an invaluable tool in the neuroscience armamentarium. However, imaging synaptic resolution connectomes is currently limited to either transmission electron microscopy (TEM) or scanning electron microscopy (SEM). Here, we describe a third way, using photoemission electron microscopy (PEEM) which illuminates ultra-thin brain slices collected on solid substrates with UV light and images the photoelectron emission pattern with a wide-field electron microscope. PEEM works with existing sample preparations for EM and routinely provides sufficient resolution and contrast to reveal myelinated axons, somata, dendrites, and sub-cellular organelles. Under optimized conditions, PEEM provides synaptic resolution; and simulation and experiments show that PEEM can be transformatively fast, at Gigahertz pixel rates. We conclude that PEEM imaging leverages attractive aspects of SEM and TEM, namely reliable sample collection on robust substrates combined with fast wide-field imaging, and could enable faster data acquisition for next-generation connectomics.

Back illuminated photo emission electron microscopy (BIPEEM).

A new, complementary technique based on Photo Emission Electron Microscopy (PEEM) is demonstrated. In contrast to PEEM, the sample is placed on a transparent substrate and is illuminated from the back side while electrons are collected from the other (front) side. In this paper, the working principle of this technique, coined back-illuminated PEEM (BIPEEM), is described. In BIPEEM, the electron intensity is strongly thickness-dependent. This dependence can be described by a simple model which contains the optical attenuation length and the electron mean free path. Electrons forming an image in BIPEEM hence carry information of the inner part of the sample, as well as of the surface, as we demonstrate experimentally.

Accuracy of magnetic resonance imaging in assessing knee cartilage changes over time in patients with osteoarthritis: A systematic review.

Magnetic resonance imaging (MRI) is a technique useful for the diagnosis of cartilage damage due to high sensitivity to identify subchondral bone abnormalities and full-thickness cartilage lesions. The lack of a study on knee cartilage changes over time in patients with osteoarthritis (OA) by MRI technique led us to investigate the accuracy of MRI in identifying knee cartilage changes over time in patients with OA in a systematic review. In the present systematic review, started from the beginning of 2020 in one of the University Hospitals in Iran, the databases of CINAHL, Ovid, Elsevier, Scopus, PubMed, Science Direct, and Web of Science were searched using the keywords MRI, OA, Cartilage Lesion, Imaging Techniques. A total of 169 articles were retrieved in the initial search, and after reviewing the titles, abstracts, and full-texts, finally, seven were enrolled in the systematic review. Review of the selected papers showed that a total of 1091 subjects were studied, of which 355 were males. The results of all the studies, except one, indicated the high accuracy of MRI to identify knee cartilage changes over time. MRI technique can show cartilage changes with high accuracy in patients with knee OA over time. We proved the potential of MRI to identify articular cartilage injuries in patients with OA and its importance to the evaluation of articular cartilage lesions along with other available techniques.

Polyethylene eye-cover versus artificial teardrops in the prevention of ocular surface diseases in comatose patients: A prospective multicenter randomized triple-blinded three-arm clinical trial.

BACKGROUND: Polyethylene covers are claimed to be useful in preventing ocular surface diseases (OSD); however, evidence of their clinical efficacy is limited. This clinical trial aimed to compare the use of polyethylene eye covers and artificial teardrops versus normal saline on the incidence and severity of OSD in comatose patients. METHODS: Of 90 eligible patients randomly assigned to three treatment groups, 79 patients completed the study, In group A, patients (n = 25) received artificial teardrops for left and normal saline for right eyes, in group B (n = 29) polyethylene covers for left and normal saline for right eyes, and in group C (n = 25) polyethylene covers for left and artificial teardrops for right eyes. As the patients were comatose, their blinding did not applicable, and a blinded observer evaluated the patients' eyes based on the Corneal Fluorescein Staining Pattern. The blinded analyzer analyzed collected data by SPSS-16 software at a 95% confidential level. RESULTS: The OSDs were observed in 65 (41.14%) out of 158 eyes examined. The artificial teardrop was more effective than the normal saline in group A, polyethylene eye cover was more useful than the normal saline in group B, and polyethylene eye cover was more effective than the artificial teardrop in group C in reducing the incidence of OSD (p< 0.01). Polyethylene eye covers had the most impact on reducing the severity of the OSD compared to the other interventions (p< .001). CONCLUSIONS: Polyethylene eye covers significantly reduced the incidence and severity of OSD. Using polyethylene cover is suggested as a safe, effective, and accessible eye care intervention for preventing OSD in comatose patients. TRIAL REGISTRATION: (IRCT201609129014N115), Iranian Registry of Clinical Trials.

The Clinical Outcome of Simultaneous Lateral Closed- Wedge Distal Femoral Osteotomy and Anterior Cruciate Ligament Reconstruction in the ACL-deficient Knees with Symptomatic Femoral Varus Deformity.

BACKGROUND: Nowadays combined high tibial osteotomy and ACL reconstruction is accepted as a safe and effective surgery for patients with symptomatic varus osteoarthritis and anterior knee instability; however, the source of varus deformity is sometimes the femoral bone. No studies have reported concomitant ACL reconstruction and distal femoral osteotomy in ACL-deficient knees with femoral varus deformity and medial osteoarthritis till now. This prospective study presents the technique and clinical outcome of a consecutive series of simultaneous lateral closed-wedge distal femoral osteotomy and ACL reconstruction. METHODS: Nineteen patients with confirmed ACL rupture and femoral varus deformity (mechanical lateral distal femoral angle ≥ 93°) associated with medial osteoarthritis (± lateral thrust) were included the study. The patients underwent simultaneous lateral closed-wedge distal femoral osteotomy and ACL reconstruction. At the end of one year follow up, the final range of motion and stability of the knees and the last alignment of extremities were recorded. Surgical outcomes were assessed on 2000 IKDS subjective scores and KOOS subscales. RESULTS: The mean preoperative varus knee was 10.6° (±2.2°) mostly from the femoral side. The mean union time was 3.2 (±0.4) months. Regarding the radiological evaluation, the alignment of extremity and mLDFA were corrected significantly compared to the pre-operative findings. At the end of one year follow up, all patients were free of knee instability. Subjective assessment based on questionnaires showed a significant improvement in all aspects of knee function after surgery, however there was no considerable change in the knees range of motion. CONCLUSION: Simultaneous lateral closed- wedge distal femoral osteotomy and ACL reconstruction is a valuable procedure in femoral varus knees with medial osteoarthritis and anterior knee instability. After one year follow up all aspects of knee function were improved without serious complications.

Laser-Induced Frequency Tuning of Fourier-Limited Single-Molecule Emitters.

The local interaction of charges and light in organic solids is the basis of distinct and fundamental effects. We here observe, at the single-molecule scale, how a focused laser beam can locally shift by hundreds of times their natural line width and, in a persistent way, the transition frequency of organic chromophores cooled at liquid helium temperature in different host matrices. Supported by quantum chemistry calculations, the results can be interpreted as effects of a photoionization cascade, leading to a stable electric field, which Stark-shifts the molecular electronic levels. The experimental observation is then applied to a common challenge in quantum photonics, i.e., the independent tuning and synchronization of close-by quantum emitters, which is desirable for multiphoton experiments. Five molecules that are spatially separated by about 50 µm and originally 20 GHz apart are brought into resonance within twice their line width. This tuning method, which does not require additional fabrication steps, is here independently applied to multiple emitters, with an emission line width that is only limited by the spontaneous decay and an inhomogeneous broadening limited to 1 nm. The system hence shows promise for photonic quantum technologies.

Allograft or autograft in skeletally immature anterior cruciate ligament reconstruction: a prospective evaluation using both partial and complete transphyseal techniques.

OBJECTIVE: We compared autografts and allograft using partial and complete transphyseal anterior cruciate ligament (ACL) reconstruction techniques among skeletally immature individuals. METHODS: Male and females younger than 18 and 16 years old, respectively, diagnosed with ACL tear from April 2006 to March 2012 entered the study. One group had four-strand hamstring autograft, and the other had tibialis posterior allograft reconstruction. Those who had allografts either had hyper-laxity or recurvatum. RESULTS: Achieved mean (± SD) 2000 International Knee Documentation Committee subjective score was not statistically different (P = 0.385) between allograft (n = 13) (84.3 ± 3.2) and autograft groups (n = 18) (85.6 ± 4.4). Mean Knee injury and Osteoarthritis Outcome Score (KOOS) subscale Knee-Related Quality of Life at 2 years was 78.0 ± 7.2 and 75 ± 7.4 for allograft and autograft groups, respectively (p = 0.261). Mean 2-year KOOS subscale Sports and Recreation was 82.1 ± 5.8 and 84.8 ± 6.6 for allograft and autograft groups, respectively (p = 0.244). No patient reported instability, giving way, or locking of the knee. Pivot shift test was negative in all patients; however, a minor positive Lachman test was found in six cases (46%) within the allograft group and seven cases (39%) in the autograft group. One postoperative septic arthritis was documented in the autograft group. CONCLUSION: Considering existing concern that joint laxity and recurvatum are among the precursors of non-contact ACL injury in adolescents, bone-patellar-bone autografts are not applicable in this age group because of the open physis; furthermore, considering that hamstring autografts are insufficient (size thickness and stretchability), we recommend soft tissue allografts for ACL reconstruction in skeletally immature patients.

Matrix-induced Linear Stark Effect of Single Dibenzoterrylene Molecules in 2,3-Dibromonaphthalene Crystal.

Absorption and fluorescence from single molecules can be tuned by applying an external electric field - a phenomenon known as the Stark effect. A linear Stark effect is associated to a lack of centrosymmetry of the guest in the host matrix. Centrosymmetric guests can display a linear Stark effect in disordered matrices, but the response of individual guest molecules is often relatively weak and non-uniform, with a broad distribution of the Stark coefficients. Here we introduce a novel single-molecule host-guest system, dibenzoterrylene (DBT) in 2,3-dibromonaphthalene (DBN) crystal. Fluorescent DBT molecules show excellent spectral stability with a large linear Stark effect, of the order of 1.5 GHz/kVcm-1 , corresponding to an electric dipole moment change of around 2 D. Remarkably, when the electric field is aligned with the a crystal axis, nearly all DBT molecules show either positive or negative Stark shifts with similar absolute values. These results are consistent with quantum chemistry calculations. Those indicate that DBT substitutes three DBN molecules along the a-axis, giving rise to eight equivalent embedding sites, related by the three glide planes of the orthorhombic crystal. The static dipole moment of DBT molecules is created by host-induced breaking of the inversion symmetry. This new host-guest system is promising for applications that require a high sensitivity of fluorescent emitters to electric fields, for example to probe weak electric fields.

Short term results of anterior cruciate ligament augmentation in professional and amateur athletes.

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction is a widely accepted procedure; however, controversies exist about ACL augmentation. The purpose of this study was to assess the clinical outcomes of ACL augmentation in professional and amateur athletes with isolated single bundle ACL tears. MATERIALS AND METHODS: A consecutive series of professional and amateur athletes with partial ACL tears who underwent selective bundle reconstruction were analyzed. Stability was assessed with the Lachman test, anterior-drawer test, pivot-shift test and KT-1000 arthrometer. Functional assessment was performed using the subjective Lysholm questionnaire. RESULTS: Fifty-six patients were enrolled. The mean follow-up period was 19.3 months. All patients had posterolateral bundle (PLB) tears, and no anteromedial bundle (AMB) tears were found. The Lysholm score improved significantly from 78 (SD = 2.69) preoperatively to 96 (SD = 3.41) postoperatively (P value <0.0001). The pivot-shift test, Lachman test and anterior-drawer test results were negative in all cases postoperatively. Anterior tibial translation from neutral was 4.9 mm (SD = 2.7) preoperatively, and decreased significantly to 2.1 (SD = 0.6) postoperatively, measured with a KT-1000 arthrometer (P value <0.00001). CONCLUSION: In this study, we showed that ACL augmentation had good results in symptomatic professional and amateur athletes, and although further studies are needed to investigate long-term results, we recommend this surgery for all symptomatic athletic patients, especially those who would like to maintain an active lifestyle. Level of evidence IV.

Digital holography based submicron thermometry.

Here we introduce a phase-shifting digital holography-based method to determine the temperature profile around an irradiated (sub-)micron spherical bead. The method utilizes a Mach-Zehnder interferometer implemented into an open setup microscope. The results of irradiated gold spheres with diameter of 400 nm and also silver-coated micron-sized silica beads embedded in silicone oil are presented. We show that the applied method is able to accurately determine the surface temperature with accuracy of 1 °C. Our experimental results perfectly confirm the theoretical prediction of temperature profile around the irradiated bead.

Does the hyperextension maneuver prevent knee extension loss after arthroscopic anterior cruciate ligament reconstruction?

BACKGROUND: Disruption of the anterior cruciate ligament (ACL) is one of the most frequent musculoskeletal injuries affecting physically active men and women. In the United States, an estimated 200,000 ACL reconstructions are performed annually. One of the most common complications of ACL reconstruction is loss of extension. The purpose of this study was to assess the effects of the hyperextension maneuver on preventing knee extension loss after arthroscopic ACL reconstruction. MATERIALS AND METHODS: In this prospective randomized clinical trial study, 100 adult patients with a documented complete ACL tear were randomized to two groups. All patients underwent arthroscopic ACL reconstruction with quadrupled semitendinosus and gracilis autograft by the senior author based on the same technique and instruments. However, the hyperextension maneuver was only performed in 50 patients during autograft fixation on the tibial side (case group). The postoperative rehabilitation protocol was similar for both groups. The knee range of motion and extension limit was evaluated at 2, 6, 12, and 24 weeks and at 1 year postoperatively. RESULTS: One hundred patients (88 male and 12 female) aged from 17-36 years (average 26.9 years) were included in our study. The two groups were similar regarding age, sex, and dominant side involvement (P >0.4).The difference between the two groups was significant only at 2 weeks (P <0.02). After 2 weeks, although the rate of limited extension was higher in the control group, no significant difference was seen between the groups. CONCLUSION: Although the hyperextension technique during graft fixation on the tibial side may induce better range of motion in the first 2 weeks after ACL reconstruction surgery, this effect is not significant after 2 weeks. LEVEL OF EVIDENCE: Therapeutic level II.

Evaluation of Distal Femoral Rotational Alignment with Spiral CT Scan before Total Knee Arthroplasty (A Study in Iranian population).

BACKGROUND: Evaluating the landmarks for rotation of the distal femur is a challenge for orthopedic surgeons. Although the posterior femoral condyle axis is a good landmark for surgeons, the surgical transepicondylar axis may be a better option with the help of preoperative CT scanning. The purpose of this study was to ascertain relationships among the axes' guiding distal femur rotational alignment in preoperative CT scans of Iranian patients who were candidates for total knee arthroplasty and the effects of age, gender, and knee alignment on these relationships. METHODS: One hundred and eight cases who were admitted to two university hospitals for total knee arthroplasty were included in this study. The rotation of the distal femur was evaluated using single axial CT images through the femoral epicondyle. Four lines were drawn digitally in this view: anatomical and surgical transepicondylar axes, posterior condylar axis and the Whiteside anteroposterior line. The alignment of the extremity was evaluated in the standing alignment view. Then the angles were measured along these lines and their relationship was evaluated. RESULTS: The mean angle between the anatomical transepicondylar axis and posterior condylar axis and between the surgical transepicondylar axis and posterior condylar axis were 5.9 ± 1.6 degrees and 1.6±1.7 degrees respectively. The mean angle between the Whiteside's anteroposterior line and the line perpendicular to the posterior condylar axis was 3.7±2.1 degrees. Significant differences existed between the two genders in these relationships. No significant correlation between the age of patients and angles of the distal femur was detected. The anatomical surgical transepicondylar axis was in 4.3 degrees external rotation in relation to the surgical transepicondylar axis. CONCLUSION: Preoperative CT scanning can help accurately determine rotational landmarks of the distal femur. If one of the reference axes cannot be determined, other reference axes can be used because of the good correlation between these landmarks.

The effect of gentamicin in irrigating solutions on articular infection prophylaxis during arthroscopic ACL reconstruction.

PURPOSE: The purpose of this study was to investigate whether gentamicin irrigation solutions provide a potential new tool to prevent joint infection after arthroscopic ACL reconstruction. METHODS: In this prospective randomized study, 360 consecutive ACL recondition patients were randomized in two groups alternately from Feb 2008 to March 2012. In the first group, 180 patients underwent ACL reconstruction with a hamstring autograft, preoperative IV antibiotics, and normal saline (0.9% sodium chloride) solution. In the second group 180 patients underwent ACL reconstruction with a hamstring autograft, preoperative IV antibiotics, and normal saline (0.9% sodium chloride solution) with added gentamicin (80 mg/L) (group 2). Three patients from group 1 and six patients from group 2 were excluded from the study due to loss of follow-up. The patients were followed for 6 months and assessed for signs of deep infection. RESULTS: In group 1, a total of 4 (2.2%) postoperative septic arthritis cases were documented. In group 2, just one postoperative deep infection (septic arthritis) was documented (0.57%). Although the rate of septic arthritis in group 1 was higher than in group 2, statistical analysis showed that the difference between using the gentamicin irrigation solution (80 mg/L) and the saline solution alone was not significant. CONCLUSIONS: Using gentamicin in irrigating solutions during arthroscopic ACL reconstruction surgery does not statistically decrease post operation septic arthritis. LEVEL OF EVIDENCE: Therapeutic Level II.

Cutaneous metastasis of bilateral renal cell carcinoma.

Renal cell carcinoma (RCC) is a malignant lethal tumour with high potential of metastasis. However, metastasis from RCC to the skin is much less common. It is virtually a sign of poor prognosis. We represent a 42 years old man with bilateral RCC of clear cell type followed by metastasis to the scalp one month later. In this case the relatively young age of the patient, bilaterality of RCC and occurance of skin metastasis in the absence of recurrent kidney tumour are interesting.

Using a vascularized bone graft from the distal metaphysis of radius in treating scaphoid nonunion: first report from a developing country.

Scaphoid fractures are common and prone to nonunion if left untreated. In this study, the outcome of using a vascularized bone graft was investigated in scaphoid nonunion. Twenty patients with scaphoid nonunion were recruited from Shohada Hospital. A reverse-flow vascularized bone graft was obtained from the distal metaphysis of radius and inserted into the gap of scaphoid fracture. Long and short thumb spica casts were used for 1.5 and 2 months thereafter, respectively. Union, motion, pain and the patients' satisfaction rate were documented. Twenty patients, 19 males and 1 female, with a mean age of 25.15 +/- 6.62 (range: 17-40) years were studied. The fractured were in the waist of the bone in 17 cases and in the proximal pole in 3 cases. Preoperative pain and pain plus compromised grip strength were reported in 11 and 9 patients, respectively. The rate of patients with pain decreased significantly after operation (100 to 25%; p < 0.001). Complications happened in 7 patients (35%) after operation including pin fracture (n = 2), change of occupation (n = 2), nonunion (n = 1), delayed union (n = 1) and irritation (n = 1). Union achieved after 10.71 +/- 1.62 (range: 8-14) weeks in average, post-operation. Mayo wrist score improved significantly at the endpoint. The range of motion of the wrist did not change significantly after operation. Eighty percent of the patients rated the satisfaction rate as good to excellent. This study is the first one from a developing country indicating that the technique of using a reverse-flow vascularized bone graft in treating scaphoid nonunion is considerably successful and safe.

Comparison between ender and unreamed interlocking nails in tibial shaft fractures.

OBJECTIVE: To compare ender nails and unreamed interlocking nails in a randomized clinical trial study. METHODS: From March 2001 to March 2003, 131 patients with tibial fractures of the central two thirds of the tibia were admitted to the emergency ward of Shohada Hospital, Tabriz, Iran and were randomized to either an ender tibial nail or an undreamed interlocking tibial nail as their primary treatment. Age, gender, types of fracture, and surgical outcomes were recorded at the time of surgery, during hospital stay, and during the course of 9 months follow-up. RESULTS: Sixty-seven patients underwent surgery with interlocking nails and 64 with ender nails. No statistically significant difference was found between the 2 groups concerning mal-union, delayed union, and device failure. Durations of hospital stay, and time needed to achieve union was significantly higher in the unreamed interlocking group. Non-union and infection rate were higher in the ender group (p<0.05). CONCLUSION: The results of our study support those of other studies that indicate the choice between the 2 methods of unreamed nailing is mainly controversial, depending on the priorities of the patient and surgeon.

The effects of zinc supplementation on serum zinc, alkaline phosphatase activity and fracture healing of bones.

OBJECTIVE: To determine the effect of zinc supplementation on callus formation, serum zinc and alkaline phosphatase activity in humans. METHODS: This randomized, double-blind, placebo controlled clinical trial was conducted on 60 patients with traumatic bone fracture referred to Shohada Hospital of Tabriz, Iran from August to December 2007. Subjects were randomly divided into 2 groups: cases (n=30), receiving one capsule of zinc sulfate consists of 50 mg zinc each day and the controls (n=30), receiving placebo for 60 days. Individual and clinical information was determined by a questionnaire: nutritional intake by 3 days food records at the beginning and the end of trial. Serum zinc and alkaline phosphatase was measured by atomic absorption spectroscopy, and by enzymatic method. Callus formation during fracture healing was evaluated by radiography of the bone. RESULTS: There was no significant difference in physical activity, gender, age, type of fractures, and nutrient intake, between the 2 groups. The administration of zinc caused a significant elevation of serum zinc and alkaline phosphatase activity. Assessment of bone x- rays showed a significant progress in callus formation in cases compared to the controls. CONCLUSION: This study shows that zinc supplementation can stimulate fracture healing, however, it needs further study.