George Babis - Profile on Academia.edu (original) (raw)

Papers by George Babis

Cureus, Jun 28, 2023

Osteoid osteomas of the talus are rarely seen. They can easily be misdiagnosed. In this case repo... more Osteoid osteomas of the talus are rarely seen. They can easily be misdiagnosed. In this case report, we present a 21-year-old man with an osteoid osteoma in the talar neck whose pain onset coincided with an ankle injury. The latter was deemed a misleading factor when making a diagnosis. Eventually, the patient was treated with surgical excision of the osteoid osteoma. The gap that resulted after the excision was filled with an autologous bone graft. A year after his operation, the patient returned to his daily activities and remained pain-free. A high index of suspicion and an appropriate imaging examination are mandated for the early diagnosis of such entities.

Journal of orthopaedics, Mar 1, 2018

Gait analysis using external skin markers provides scope for the study of kinematic and kinetic p... more Gait analysis using external skin markers provides scope for the study of kinematic and kinetic parameters shown on different total knee arthroplasties (TKA). Thus an appropriate methodology is of great importance for the collection and correlation of valid data. Calibration of equipment is of great importance before measurements, to assure accuracy. Force plates should be calibrated to 1080 Hz and optoelectronic cameras should use 120 Hz frequency, because of the nature of gait activity. Davis model which accurately defines the position of the markers is widely accepted and cited, for the gait analysis of TKA's. To ensure the reproducibility of the measurement, a static trial at the anatomical position must be captured. Following, all acquisitions of dynamic data must be checked for consistency in walking speed, and abnormal gait style because of fatigue or distraction. To establish the repeatability of the measurement, this procedure must be repeated at a pre-defined number of 3-5 gait cycles. Anthropometric measurements should be combined with three-dimensional marker data from the static trial to provide positions of the joint's center and define anatomical axes of total knee arthroplasty. Kinetic data should be normalized to bodyweight (BW) and percentage of BW and height depending on the study. External moments should also be calculated by using inverse dynamics and amplitude-normalized to body mass (Nm/kg). Gait analysis using external skin markers provides scope for the study of biomechanical parameters shown on different TKAs. Thus a standard gait analysis methodology when measuring TKA biomechanical parameters is necessary for the collection and correlation of accurate, adequate, valid and reproducible data. Further research should be done to clarify if the development of a specific kinematic model is appropriate for a more accurate definition of total knee implant joint center in measurements concerning 3D gait analysis.

Journal of Medical Engineering & Technology, Jan 2, 2019

Gait analysis is a significant diagnostic procedure for the clinicians who manage musculoskeletal... more Gait analysis is a significant diagnostic procedure for the clinicians who manage musculoskeletal disorders. Surface electromyography (sEMG) combined with kinematic and kinetic data is a useful tool for decision making of the appropriate method needed to treat such patients. sEMG has been used for decades to evaluate neuromuscular responses during a range of activities and develop rehabilitation protocols. The sEMG methodology followed by researchers assessed the issues of noise control, wave frequency, cross talk, low signal reception, muscle co-contraction, electrode placement protocol and procedure as well as EMG signal timing, intensity and normalisation so as to collect accurate, adequate and meaningful data. Further research should be done to provide more information related to the muscle activity recorded by sEMG and the force produced by the corresponding muscle during gait analysis.

The impact of glenoid parameters and implant overstuffing on functional outcomes of shoulder hemiarthroplasty in patients with glenohumeral joint arthritis

European Journal of Orthopaedic Surgery and Traumatology, May 22, 2023

Cobalt–Chrome Porous-Coated Implant-Bone Interface in Total Joint Arthroplasty

Springer eBooks, Oct 4, 2013

Cobalt–chrome (Co–Cr) is a metal alloy of cobalt and chromium with a very high specific strength.... more Cobalt–chrome (Co–Cr) is a metal alloy of cobalt and chromium with a very high specific strength. For as long as investment casting has been available as an industrial process, cobalt-based alloys have been used in demanding applications including dental and orthopedic implants [1]. The alloy composition used in orthopedic implants, described in industry standard ASTM-F75, is composed of cobalt with (1) chromium (27–30 %) and (2) molybdenum (5–7 %) and (3) limits on other important elements such as manganese and silicon (<1 %), iron (<0.75 %), nickel (<0.5 %), and carbon, nitrogen, tungsten, phosphorus, sulfur, boron, etc. [1]. Besides cobalt–chromium–molybdenum (Co–Cr–Mo), cobalt–nickel–chromium–molybdenum (Co–Ni–Cr–Mo) is also used for implants (Table 5.1) [2, 3].

Medicina-lithuania, Feb 8, 2023

Introduction: Neuromuscular Diseases (NMD) are associated with decreased bone strength due to alt... more Introduction: Neuromuscular Diseases (NMD) are associated with decreased bone strength due to altered muscle-bone interaction. However, the evaluation of bone quality remains a certain challenge in these patients. The purpose of this scoping review is to investigate the recent literature regarding the assessment of Bone Mineral Density (BMD) in this population. Methods: An electronic search of the PubMed and Scopus database was performed considering studies published in the English literature after 2007 that evaluated BMD in pediatric and adolescent patients with NMD. We excluded studies that evaluated patients >20 years, studies not involving humans, and studies investigating bone mineral density in various pediatric conditions, but without specific data on NMD. Results: Overall, 19 studies were included that evaluated BMD in 1983 patients with NMD. Duchenne Muscular Dystrophy was the most widely studied disease (n = 11 studies). Dual energy X-ray absorptiometry (DEXA) was the most common diagnostic modality for BMD evaluation, while the most frequent site for BMD measurement was the lumbar spine (89.4%, n = 17 studies), followed by total body BMD (68.4%, n = 13 studies). Low BMD in children with NMD was demonstrated in all studies, especially after loss of ambulation. Moreover, a positive correlation between lower BMD and older age was shown. Conclusions: BMD evaluation in NMD remains a clinical challenge, as indicated by the high heterogeneity regarding the optimal site and technique for the evaluation of bone quality in these patients. Although DXA is currently the diagnostic modality of choice, a consensus regarding the optimal site for BMD measurement, and the adjustment method for its obtained measurements for parameters such as age and height is needed.

Life, Dec 8, 2021

In vitro measurements are widely used to implement gait kinematic and kinetic parameters to predi... more In vitro measurements are widely used to implement gait kinematic and kinetic parameters to predict THA wear rate. Clinical tests of materials and designs are crucial to prove the accuracy and validate such measurements. This research aimed to examine the effect of CoC and CoXLPE kinematics and kinetics on wear during gait, the essential functional activity of humans, by comparing in vivo data to in vitro results. Our study hypothesis was that both implants would present the same hip joint kinematics and kinetics during gait. In total, 127 unilateral primary cementless total hip arthroplasties were included in the research. There were no statistically significant differences observed at mean peak abduction, flexion, and extension moments and THA kinematics between the two groups. THA gait kinematics and kinetics are crucial biomechanical inputs associated with implant wear. In vitro studies report less wear in CoC than CoXLPE when tested in a matched gait kinematic protocol. Our findings confirm that both implants behave identically in terms of kinematics in a clinical environment, thus strengthening CoC advantage in in vitro results. Correlated to all other significant factors that affect THA wear, it could address in a complete prism the wear on CoC and CoXLPE.

Journal of Hand Surgery (European Volume), 2019

Reconstruction of the interosseous membrane has the potential to re-establish a normal loading pa... more Reconstruction of the interosseous membrane has the potential to re-establish a normal loading pattern through the forearm and enhance stability after an Essex-Lopresti lesion. The aim of our study was to assess the capacity of three different techniques, which all use a regionally harvested autograft, to restore longitudinal stability. Simulation of the Essex-Lopresti lesion was done by excising the radial head and sectioning the interosseous membrane in seven cadaveric specimens. Each technique was used in each specimen consecutively, using the pronator teres, the brachioradialis and the flexor carpi radialis tendons, respectively. The specimens were submitted to mechanical testing by applying proximally migratory forces to the radius and radioulnar displacement was assessed fluroscopically at wrist level. The pronator teres tendon achieved the greatest reduction (94% correction with respect to the intact interosseous membrane/radial head out state, followed by brachioradialis (92...

EFORT open reviews, Jun 1, 2021

Pelvic discontinuity (PD) has been a considerable challenge for the hip revision arthroplasty sur... more Pelvic discontinuity (PD) has been a considerable challenge for the hip revision arthroplasty surgeon. However, not all PDs are the same. Some occur during primary cup insertion, resembling a fresh periprosthetic fracture that separates the superior and inferior portions of the pelvis, while others are chronic as a result of gradual acetabular bone loss due to osteolysis and/or acetabular implant loosening. In the past, ORIF, various types of cages, bone grafts and bone cement were utilized with little success. Today, the biomechanics and biology of PD as well as new diagnostic tools and especially a variety of new implants and techniques are available to hip revision surgeons. Ultraporous cups and augments, cup-cage constructs and custom triflange components have revolutionized the treatment of PD when used in various combinations with ORIF and bone grafts. For chronic PD the cup-cage construct is the most popular method of reconstruction with good medium-term results. Dislocation continues to be the leading cause of failure in all situations, followed by infection. Ultimately, surgeons today have a big enough armamentarium to select the best treatment approach. Case individualization, personal experience and improvisation are the best assets to drive treatment decisions and strategies.

British Journal of Surgery, 2021

Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numb... more Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst ...

Journal of Tissue Engineering and Regenerative Medicine, Dec 17, 2017

To demonstrate whether and to what extent a single injection of Platelet-Rich Plasma (PRP), under... more To demonstrate whether and to what extent a single injection of Platelet-Rich Plasma (PRP), under ultrasound guidance, can improve the clinical symptoms of patients with a mild to moderate carpal tunnel syndrome (CTS). Methods: We conducted a prospective, randomized, clinical study including 50 patients suffering from mild to moderate CTS for a minimum duration of 3-months. Patients were randomly divided into two groups: A (26 patients) received an ultrasound-guided PRP injection into the carpal tunnel, whereas Group B (24 patients) was injected with placebo (0.9% normal saline, N/S). The short and mid-term outcomes were determined with the use of the Q-DASH questionnaire and the pain scale VAS administered at 0, 4, 12 weeks followup. The success ratio was determined by the difference in the Q-DASH obtained pre-injection minus the final Q-DASH obtained after 12 weeks follow-up. Success was defined as a difference more than 25%. Results: Group A patients demonstrated a 76.9% success as determined by the difference Q-DASH, while group B patients demonstrated 33.3% success, which was significantly less than group A (Χ², p=0.011). Conclusion: The findings of the present study suggest that a single PRP ultrasound-guided injection has positive effects in patients with carpal tunnel syndrome.

Accuracy and Interobserver and Intraobserver Reliability of Ultrasound in the Early Diagnosis of Occult Scaphoid Fractures: Diagnostic Criteria and a Way of Interpretation

PubMed, 2019

The purpose of this study was to illustrate the usefulness of ultrasound in the early diagnosis o... more The purpose of this study was to illustrate the usefulness of ultrasound in the early diagnosis of occult scaphoid fractures. Forty-eight patients with clinical symptoms of scaphoid fracture and negative initial X-rays were examined. All patients underwent ultrasonography in the emergency room (ER). After 14 days, a computed tomography (CT) scan was performed, which confirmed or not the initial suspicion of fracture. Twenty-two patients were found with subperiosteal hematoma, while six also had cortical discontinuity. The sensitivity of ultrasound in the diagnosis of occult scaphoid fractures was 90% and the specificity was 85.7%. The positive prognostic value was 81.8%. The authors support the use of the scaphoid ultrasound only under strict circumstances. If subperiosteal hematoma or cortical discontinuity is present, there is a high likelihood of scaphoid fracture. On the contrary, if the ultrasound is negative and symptoms persist, the patient will require a CT scan or magnetic resonance imaging for definitive diagnosis. (Journal of Surgical Orthopaedic Advances 28(1):1-9, 2019).

Comment on: “Intraoperative 3D Hologram Support With Mixed Reality Techniques in Liver Surgery”

Annals of Surgery, Jul 7, 2020

To the Editor I t was our pleasure to read the article by Saito et al, who investigated the poten... more To the Editor I t was our pleasure to read the article by Saito et al, who investigated the potential of an intraoperative threedimensional hologram with mixed reality (MR) techniques in liver surgery. The authors defined MR as ‘‘the result of blending the physical world with the digital world,’’ citing the articles by Condino et al and Tepper et al. However, supposing that this definition is correct, what is the difference between MR and augmented reality (AR)? In the article by Condino et al it was stated that MR was used for developing a simulator of orthopedic open surgery. However, a clear definition of MR was not given and, moreover, in the figure describing the flowchart of the experiment, the authors used the term ‘‘AR’’ and not ‘‘MR.’’ Tepper et al did not also provide a clear definition of MR to describe its specific characteristics, but simply stated that it combines AR with virtual reality. The authors also argued that AR does not permit interaction with 3-dimensional data packets. However, AR is a technology which superimposes digital with real objects and does permit interaction with both types of objects. MR also superimposes digital with real content, but, in contrast with AR, enables users to perceive depth and perspective of the virtual elements. Sauer et al published a paper in Annals of Surgery, according to which MR was implemented in visceral surgery. Gheza and Raimondi commented on this paper, stating that Sauer et al had in fact experienced ‘‘AR’’ and not ‘‘MR.’’ As a response to this comment, it was stated that, in the paper by Sauer et al, the difference between AR and MR was visualized: the former technology overlays digital content on real world, whereas the latter permits coexistence of digital with real world, along with interaction. These definitions also disagree with the 4–6

Association of vitamin D, BMD and knee osteoarthritis in postmenopausal women

PubMed, Dec 1, 2021

Objectives: The aim of this study was to analyze the association of knee OA with bone mineral den... more Objectives: The aim of this study was to analyze the association of knee OA with bone mineral density (BMD) and vitamin D serum levels in postmenopausal women. Methods: A cross-sectional study including 240 postmenopausal women with knee OA was conducted. Demographic data were recorded along with balance and functionality scores. Knee OA severity was assessed by the radiological Kellgren & Lawrence scale. BMD and T-scores were calculated in hips and lumbar spine. Serum levels of vitamin D were also measured. Results: High BMI (p<0.005), high number of children (p=0.022) and family history of hip fracture (p=0.011) are significantly associated with knee OA severity. Lumbar spine OP is negatively associated with knee OA (p<0.005). A significant difference was detected between vitamin D deficiency and severe knee OA, adjusted for BMD [OR (95%CI); 3.1 (1.6-6.1), p=0.001]. BMD does not affect the relationship of vitamin D levels in relation to OA and vitamin D levels do not affect the relationship of BMD with OA. Conclusions: Low BMD has a protective role against knee OA while vitamin D deficiency contributes significantly to knee OA severity. However, the association between OA and OP is not affected by vitamin D deficiency and the association of OA and vitamin D serum levels is not affected by BMD.

Letter to the Editor Regarding “Mixed Reality-Based Preoperative Planning for Training of Percutaneous Transforaminal Endoscopic Discectomy: A Feasibility Study”

World Neurosurgery, Jul 1, 2020

Comparing Guided to Blind Dissolution of Supraspinatus Calcific Deposits

Orthopaedic Proceedings, Feb 21, 2018

Background To determine if double needle ultrasound-guided hydrodissolution and aspiration of int... more Background To determine if double needle ultrasound-guided hydrodissolution and aspiration of intratendinous calcification is more effective treatment than blind subacromial corticosteroid injection. Methods A prospective randomised comparative clinical study of 32 patients suffering from chronic symptomatic calcific tendinosis of the supraspinatous tendon. Group A (16 patients) received a double needle ultrasound-guided aspiration of the calcification, while group B (16 patients) underwent a blind subacromial betamethazone injection. As far as group A, we attached a syringe in the first needle, including 10cc. of normal saline (N/S), that we injected targeting the calcium deposit. Then we tried to achieve consecutive aspirations through the second needle. Results Patients were evaluated by an independent researcher who measured the visual analogue scale (VAS) 100/100 and the range of motion (ROM): a. before, b. 10 days and c. 6 months after the injection. In most cases of group A, we observed a noticeable amount of aspirated milky or mixed white-red coloured fluid at the bottom of the syringe. This fact proves right and effective guidance of the ultrasound. After six months, we documented full –or almost full- decline (VAS: 0–20/100) of the symptoms in 62.75 % of the group A patients and in 43.75% of the group B patients. The 6 month9s mean VAS fall rate was 45/100 in group A and 33/100 in group B. Corticosteroid injected patients proved to have better outcome inside the first 10 days. The mean abduction of the humerus in the 6 month9s follow-up was 110 degrees (from 77.5 degrees prior to aspiration) for the group A and 85 degrees for group B (from 72.5 degrees -prior). Conclusion Double needle dissolution -and aspiration- with N/S represents better long-term results (regarding ROM and pain release) than blind corticosteroid injection in the treatment of chronic symptomatic calcific tendinosis. Level I

The Lancet

Background The 2015 Lancet Commission on global surgery identified surgery and anaesthesia as ind... more Background The 2015 Lancet Commission on global surgery identified surgery and anaesthesia as indispensable parts of holistic health-care systems. However, COVID-19 exposed the fragility of planned surgical services around the world, which have also been neglected in pandemic recovery planning. This study aimed to develop and validate a novel index to support local elective surgical system strengthening and address growing backlogs. Methods First, we performed an international consultation through a four-stage consensus process to develop a multidomain index for hospital-level assessment (surgical preparedness index; SPI). Second, we measured surgical preparedness across a global network of hospitals in high-income countries (HICs), middle-income countries (MICs), and low-income countries (LICs) to explore the distribution of the SPI at national, subnational, and hospital levels. Finally, using COVID-19 as an example of an external system shock, we compared hospitals' SPI to their planned surgical volume ratio (SVR; ie, operations for which the decision for surgery was made before hospital admission), calculated as the ratio of the observed surgical volume over a 1-month assessment period between June 6 and Aug 5, 2021, against the expected surgical volume based on hospital administrative data from the same period in 2019 (ie, a pre-pandemic baseline). A linear mixed-effects regression model was used to determine the effect of increasing SPI score. Findings In the first phase, from a longlist of 103 candidate indicators, 23 were prioritised as core indicators of elective surgical system preparedness by 69 clinicians (23 [33%] women; 46 [67%] men; 41 from HICs, 22 from MICs, and six from LICs) from 32 countries. The multidomain SPI included 11 indicators on facilities and consumables, two on staffing, two on prioritisation, and eight on systems. Hospitals were scored from 23 (least prepared) to 115 points (most prepared). In the second phase, surgical preparedness was measured in 1632 hospitals by 4714 clinicians from 119 countries. 745 (45•6%) of 1632 hospitals were in MICs or LICs. The mean SPI score was 84•5 (95% CI 84•1-84•9), which varied between HIC (88•5 [89•0-88•0]), MIC (81•8 [82•5-81•1]), and LIC (66•8 [64•9-68•7]) settings. In the third phase, 1217 (74•6%) hospitals did not maintain their expected SVR during the COVID-19 pandemic, of which 625 (51•4%) were from HIC, 538 (44•2%) from MIC, and 54 (4•4%) from LIC settings. In the mixed-effects model, a 10-point increase in SPI corresponded to a 3•6% (95% CI 3•0-4•1; p<0•0001) increase in SVR. This was consistent in HIC (4•8% [4•1-5•5]; p<0•0001), MIC (2•8 [2•0-3•7]; p<0•0001), and LIC (3•8 [1•3-6•7%]; p<0•0001) settings. Interpretation The SPI contains 23 indicators that are globally applicable, relevant across different system stressors, vary at a subnational level, and are collectable by front-line teams. In the case study of COVID-19, a higher SPI was associated with an increased planned surgical volume ratio independent of country income status, COVID-19 burden, and hospital type. Hospitals should perform annual self-assessment of their surgical preparedness to identify areas that can be improved, create resilience in local surgical systems, and upscale capacity to address elective surgery backlogs.

Serum biomarkers for the assessment of muscle damage in various surgical approaches in primary total hip arthroplasty: a systematic review of comparative studies

International Orthopaedics

Nature Communications, 2022

Back pain is a common and debilitating disorder with largely unknown underlying biology. Here we ... more Back pain is a common and debilitating disorder with largely unknown underlying biology. Here we report a genome-wide association study of back pain using diagnoses assigned in clinical practice; dorsalgia (119,100 cases, 909,847 controls) and intervertebral disc disorder (IDD) (58,854 cases, 922,958 controls). We identify 41 variants at 33 loci. The most significant association (ORIDD = 0.92, P = 1.6 × 10−39; ORdorsalgia = 0.92, P = 7.2 × 10−15) is with a 3’UTR variant (rs1871452-T) in CHST3, encoding a sulfotransferase enzyme expressed in intervertebral discs. The largest effects on IDD are conferred by rare (MAF = 0.07 − 0.32%) loss-of-function (LoF) variants in SLC13A1, encoding a sodium-sulfate co-transporter (LoF burden OR = 1.44, P = 3.1 × 10−11); variants that also associate with reduced serum sulfate. Genes implicated by this study are involved in cartilage and bone biology, as well as neurological and inflammatory processes.