Amir Herman
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Amir Herman has a total of 63 co-authors. Here are the top co-authors by number of shared publications:
Candice Dubose
Center for Orthopaedic Research and Education, University of Arizona at Phoenix, Phoenix, Arizona
2 shared publicationsEmily Keener
Hughston Clinic, Orange Park, Florida
2 shared publicationsJason A. Lowe
Center for Orthopaedic Research and Education, University of Arizona at Phoenix, Phoenix, Arizona
2 shared publicationsMoshe Salai
Department of Orthopedic Surgery, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
2 shared publicationsNachshon Shazar
Department of Orthopaedic Surgery, Sheba Medical Center, Tel HaShomer, Israel
2 shared publicationsShay Tenenbaum
Department of Orthopaedic Surgery, Sheba Medical Center, Tel HaShomer, Israel
2 shared publications
Latest Publications
- 1 July 2021
- Published by Elsevier in The American Journal of Surgery
- Vol. 222 (1) , 214-219
The impact of bariatric surgery on nonalcoholic fatty liver disease as measured using non-invasive tests
- 1 July 2021
- Published by Elsevier in The American Journal of Surgery
- Vol. 222 (1) , 214-219
The impact of bariatric surgery on nonalcoholic fatty liver disease as measured using non-invasive tests
- Open Access
- 31 October 2020
- Published by Asian Spine Journal (ASJ) in Asian Spine Journal
- Vol. 14 (5) , 639-646
Use of Intraoperative Tranexamic Acid and Wound Complications in Spine Surgery: A Retrospective Cohort Study
Study Design: A retrospective cohort study.Purpose: This study aims to examine the effect of tranexamic acid (TXA) on postoperative wound healing in spine surgery.Overview of Literature: TXA (Cyklokapron, Hexakapron) is a widely used anti-fibrinolytic drug that is shown to be effective in mitigating hemorrhage during and after surgery by competitively blocking plasminogen in fibrinolytic cascade. Plasminogen also plays a role in inflammatory and infectious diseases. The modulation of this role by TXA may influence the development of postoperative infectious complications.Methods: We collected and reviewed the charts of 110 patients who underwent spine surgery at our academic center. We used multivariate regression analysis to assess the factors affecting surgical site infection (SSI).Results: Of the 110 patients included in this study, 21 patients (19%) were categorized as having postoperative wound complications, 16 patients (14%) had deep or superficial wound infection, and five patients (4%) had wound dehiscence. Patients with a higher surgical invasiveness index score, longer surgeries, and older patients were found to be at risk for wound complications. TXA was determined not to be a direct risk factor for wound healing complications and SSIs.Conclusions: We found no risk of wound healing complications and SSI directly attributable to preoperative and intraoperative treatment with TXA in spine surgeries.
- 31 October 2020
- Published by Asian Spine Journal (ASJ) in Asian Spine Journal
- Vol. 14 (5) , 639-646
Open AccessUse of Intraoperative Tranexamic Acid and Wound Complications in Spine Surgery: A Retrospective Cohort Study
Study Design: A retrospective cohort study.Purpose: This study aims to examine the effect of tranexamic acid (TXA) on postoperative wound healing in spine surgery.Overview of Literature: TXA (Cyklokapron, Hexakapron) is a widely used anti-fibrinolytic drug that is shown to be effective in mitigating hemorrhage during and after surgery by competitively blocking plasminogen in fibrinolytic cascade. Plasminogen also plays a role in inflammatory and infectious diseases. The modulation of this role by TXA may influence the development of postoperative infectious complications.Methods: We collected and reviewed the charts of 110 patients who underwent spine surgery at our academic center. We used multivariate regression analysis to assess the factors affecting surgical site infection (SSI).Results: Of the 110 patients included in this study, 21 patients (19%) were categorized as having postoperative wound complications, 16 patients (14%) had deep or superficial wound infection, and five patients (4%) had wound dehiscence. Patients with a higher surgical invasiveness index score, longer surgeries, and older patients were found to be at risk for wound complications. TXA was determined not to be a direct risk factor for wound healing complications and SSIs.Conclusions: We found no risk of wound healing complications and SSI directly attributable to preoperative and intraoperative treatment with TXA in spine surgeries.
- 20 March 2019
- Published by Wolters Kluwer Health in Journal of Bone and Joint Surgery
- Vol. 101 (6) , e25
As Good as Current Evidence Can Get
CommentaryIn their retrospective study, “The Use of Aspirin for Prophylaxis Against Venous Thromboembolism Decreases Mortality Following Primary Total Joint Arthroplasty,” Rondon et al. compared mortality rates of patients who received aspirin as prophylaxis against venous thromboembolism (VTE) with
- 20 March 2019
- Published by Wolters Kluwer Health in Journal of Bone and Joint Surgery
- Vol. 101 (6) , e25
As Good as Current Evidence Can Get
CommentaryIn their retrospective study, “The Use of Aspirin for Prophylaxis Against Venous Thromboembolism Decreases Mortality Following Primary Total Joint Arthroplasty,” Rondon et al. compared mortality rates of patients who received aspirin as prophylaxis against venous thromboembolism (VTE) with
- 1 January 2019
- Published by SLACK, Inc. in Orthopedics
- Vol. 42 (1) , 34-40
Classic Markers for Infection Perform Poorly in Predicting Residual Infection Prior to Reimplantation
Two-stage exchange arthroplasty remains the treatment of choice for chronic periprosthetic joint infections. This retrospective study conducted between 2009 and 2015 examined the diagnostic value of biomarkers for residual infection between stages. The biomarkers evaluated included C-reactive protein prior to reimplantation, preimplantation synovial fluid white blood cell count and percent neutrophils, and the intraoperative histologic synovial white blood cell count per high-power field (×400) on permanent sections. Residual infection was defined as either positive cultures (more than 1) at second stage, any further surgery (eg, amputation, arthrodesis, or another 2-stage revision), or the need for infection suppression with antibiotics. Sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated accordingly. A total of 182 two-stage exchange operations that included 109 (59.9%) prosthetic hips and 73 (40.1%) prosthetic knees met the inclusion criteria. Residual infection was present in 38 (20.9%) of the procedures. The area under the curve–receiver operating characteristic values were 0.677 for C-reactive protein ( P =.002), 0.506 for aspiration white blood cell count ( P =.944), 0.623 for aspiration percent neutrophils ( P =.200), and 0.524 for white blood cell count per high-power field ( P =.801). Positive and negative predictive values were poor and ranged between 26% and 57% and 78% and 85%, respectively. Analyses using specific combinations of biomarkers did not significantly improve predictive values. This study showed that classic markers perform poorly in identifying residual infection prior to second-stage revision. Further research is necessary to evaluate the diagnostic utility of other, more recently introduced biomarkers to determine whether infection has been eradicated between stages. [ Orthopedics . 2019; 42(1):34–40.]
- 1 January 2019
- Published by SLACK, Inc. in Orthopedics
- Vol. 42 (1) , 34-40
Classic Markers for Infection Perform Poorly in Predicting Residual Infection Prior to Reimplantation
Two-stage exchange arthroplasty remains the treatment of choice for chronic periprosthetic joint infections. This retrospective study conducted between 2009 and 2015 examined the diagnostic value of biomarkers for residual infection between stages. The biomarkers evaluated included C-reactive protein prior to reimplantation, preimplantation synovial fluid white blood cell count and percent neutrophils, and the intraoperative histologic synovial white blood cell count per high-power field (×400) on permanent sections. Residual infection was defined as either positive cultures (more than 1) at second stage, any further surgery (eg, amputation, arthrodesis, or another 2-stage revision), or the need for infection suppression with antibiotics. Sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated accordingly. A total of 182 two-stage exchange operations that included 109 (59.9%) prosthetic hips and 73 (40.1%) prosthetic knees met the inclusion criteria. Residual infection was present in 38 (20.9%) of the procedures. The area under the curve–receiver operating characteristic values were 0.677 for C-reactive protein ( P =.002), 0.506 for aspiration white blood cell count ( P =.944), 0.623 for aspiration percent neutrophils ( P =.200), and 0.524 for white blood cell count per high-power field ( P =.801). Positive and negative predictive values were poor and ranged between 26% and 57% and 78% and 85%, respectively. Analyses using specific combinations of biomarkers did not significantly improve predictive values. This study showed that classic markers perform poorly in identifying residual infection prior to second-stage revision. Further research is necessary to evaluate the diagnostic utility of other, more recently introduced biomarkers to determine whether infection has been eradicated between stages. [ Orthopedics . 2019; 42(1):34–40.]
- 1 January 2019
- Published by Elsevier in The Journal of Arthroplasty
- Vol. 34 (1) , 47-55
A Biomechanical Foot-Worn Device Improves Total Knee Arthroplasty Outcomes
- 1 January 2019
- Published by Elsevier in The Journal of Arthroplasty
- Vol. 34 (1) , 47-55
A Biomechanical Foot-Worn Device Improves Total Knee Arthroplasty Outcomes
- 17 January 2018
- Published by Wolters Kluwer Health in Journal of Bone and Joint Surgery
- Vol. 100 (2) , e8
There Is No Column: A New Classification for Acetabular Fractures
Background: The surgical treatment of acetabular fractures relies on the understanding of fracture architecture and their classification. The Judet and Letournel classification has been the cornerstone in understanding and treating acetabular fractures. Recently, there has been growing evidence of discrepancies and incompleteness in the Judet and Letournel classification, adversely affecting its clinical use. This study describes a novel comprehensive classification system that will direct surgical approach and fixation methods.Methods: A retrospective study of patients with acetabular fractures treated at a level-I trauma center also serving as a referral center for acetabular fractures was performed. Fractures were classified according to both the novel and Judet and Letournel classification systems. The novel classification developed integrates the displacement vector (posterior, superomedial, or combined) and the fractured anatomic structures (anteroposterior wall, pelvic brim, iliac wing, quadrilateral plate, and ischium). Furthermore, postoperative malreduction was evaluated on the basis of intra-articular gap measurements in either anteroposterior or Judet oblique views.Results: The study included 229 patients with acetabular fractures treated between 2007 and 2016. The mean patient age (and standard deviation) was 46.7 ± 21.75 years, and 172 patients (75.1%) were surgically treated. According to the novel classification system, the posterior displacement vector group included 60 patients, the superomedial displacement vector group included 130 patients, the combined displacement vector group included 36 patients, and 3 patients were unclassified by the new system. Forty-six patients (20.1%) could not be classified by the Judet and Letournel classification. Pelvic-brim fracture patterns were described as along the pelvic brim, across the pelvic brim, or comminuted. The quadrilateral plate primary fracture line was shown to be perpendicular to the pelvic brim. The selection of surgical approach and fixation methods depends on the fracture type.Conclusions: This study presents a novel classification system for acetabular fractures. It offers a complete classification system, encompassing nearly all fracture patterns. As the selection of surgical approach and fixation methods depends on fracture classification and understanding, the novel classification system can aid the surgeon with decision-making.
- 17 January 2018
- Published by Wolters Kluwer Health in Journal of Bone and Joint Surgery
- Vol. 100 (2) , e8
There Is No Column: A New Classification for Acetabular Fractures
Background: The surgical treatment of acetabular fractures relies on the understanding of fracture architecture and their classification. The Judet and Letournel classification has been the cornerstone in understanding and treating acetabular fractures. Recently, there has been growing evidence of discrepancies and incompleteness in the Judet and Letournel classification, adversely affecting its clinical use. This study describes a novel comprehensive classification system that will direct surgical approach and fixation methods.Methods: A retrospective study of patients with acetabular fractures treated at a level-I trauma center also serving as a referral center for acetabular fractures was performed. Fractures were classified according to both the novel and Judet and Letournel classification systems. The novel classification developed integrates the displacement vector (posterior, superomedial, or combined) and the fractured anatomic structures (anteroposterior wall, pelvic brim, iliac wing, quadrilateral plate, and ischium). Furthermore, postoperative malreduction was evaluated on the basis of intra-articular gap measurements in either anteroposterior or Judet oblique views.Results: The study included 229 patients with acetabular fractures treated between 2007 and 2016. The mean patient age (and standard deviation) was 46.7 ± 21.75 years, and 172 patients (75.1%) were surgically treated. According to the novel classification system, the posterior displacement vector group included 60 patients, the superomedial displacement vector group included 130 patients, the combined displacement vector group included 36 patients, and 3 patients were unclassified by the new system. Forty-six patients (20.1%) could not be classified by the Judet and Letournel classification. Pelvic-brim fracture patterns were described as along the pelvic brim, across the pelvic brim, or comminuted. The quadrilateral plate primary fracture line was shown to be perpendicular to the pelvic brim. The selection of surgical approach and fixation methods depends on the fracture type.Conclusions: This study presents a novel classification system for acetabular fractures. It offers a complete classification system, encompassing nearly all fracture patterns. As the selection of surgical approach and fixation methods depends on fracture classification and understanding, the novel classification system can aid the surgeon with decision-making.
- 19 September 2016
- Published by Wiley in Journal of Orthopaedic Research
- Vol. 35 (7) , 1478-1484
Simple mathematical model of sacroiliac screws safe-zone-Easy to implement by pelvic inlet and outlet views
Percutaneous sacral screw fixation is the mainstay of posterior pelvic ring fixation. This study quantifies the accuracy of fluoroscopic screw placement using post-operative CT scans and redefines the fluoroscopic safe zone using a mathematical calculation obtained from Inlet and outlet images. The authors hypothesized that a mathematical calculation of screw placement within the ala will improve accuracy of screw placement. A retrospective review of consecutive patients admitted to a level 1 trauma center with pelvic fractures fixed with iliosacral screws from January 2011 to December 2014 was performed. Accuracy of screw placement was determined by comparing fluoroscopy to post-operative CT scans. A mathematical calculation of screw position within the sacral ala was applied to determine assess screw position and compared to CT findings. Ninety-four patients with 156 screws met inclusion criteria, of which 50 (32.0%) had a cortical breech on CT. The sensitivity and specificity of the inlet–outlet safe zone using mathematical calculation were 97.1% and 84.0%, respectively. The positive and negative predictive values were 92.7% and 93.3%, respectively. Overall accuracies of the radiographic inlet–outlet and lateral safe zones were 92.9% and 70.0%, respectively (p-value = 0.004). Sacral dysmorphism was not found to be associated with sacral cortical breech. A Simple mathematical calculation (screw position relative to percentage of bone width) on the inlet–outlet provides an accurate way to predict the accuracy of sacroiliac screws. The method is easy to implement, part of the surgery work-flow, and provides higher accuracy than relying on subjective interpretation of inlet, outlet, and lateral images. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
- 19 September 2016
- Published by Wiley in Journal of Orthopaedic Research
- Vol. 35 (7) , 1478-1484
Simple mathematical model of sacroiliac screws safe-zone-Easy to implement by pelvic inlet and outlet views
Percutaneous sacral screw fixation is the mainstay of posterior pelvic ring fixation. This study quantifies the accuracy of fluoroscopic screw placement using post-operative CT scans and redefines the fluoroscopic safe zone using a mathematical calculation obtained from Inlet and outlet images. The authors hypothesized that a mathematical calculation of screw placement within the ala will improve accuracy of screw placement. A retrospective review of consecutive patients admitted to a level 1 trauma center with pelvic fractures fixed with iliosacral screws from January 2011 to December 2014 was performed. Accuracy of screw placement was determined by comparing fluoroscopy to post-operative CT scans. A mathematical calculation of screw position within the sacral ala was applied to determine assess screw position and compared to CT findings. Ninety-four patients with 156 screws met inclusion criteria, of which 50 (32.0%) had a cortical breech on CT. The sensitivity and specificity of the inlet–outlet safe zone using mathematical calculation were 97.1% and 84.0%, respectively. The positive and negative predictive values were 92.7% and 93.3%, respectively. Overall accuracies of the radiographic inlet–outlet and lateral safe zones were 92.9% and 70.0%, respectively (p-value = 0.004). Sacral dysmorphism was not found to be associated with sacral cortical breech. A Simple mathematical calculation (screw position relative to percentage of bone width) on the inlet–outlet provides an accurate way to predict the accuracy of sacroiliac screws. The method is easy to implement, part of the surgery work-flow, and provides higher accuracy than relying on subjective interpretation of inlet, outlet, and lateral images. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
- 22 January 2015
- Published by Springer Nature in Clinical Rheumatology
- Vol. 34 (11) , 1955-1960
The correlation between radiographic knee OA and clinical symptoms—do we know everything?
This study aims to evaluate the correlations between common clinical osteoarthritis (OA) diagnostic tools in order to determine the value of each. A secondary goal was to investigate the influence of gender differences on the findings. Five hundred and eighteen patients with knee OA were evaluated using the Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire, short form 36 (SF-36) Health Survey, and plain radiographs. Analysis of variance (ANOVA) was used to compare the different domains of the WOMAC and SF-36 questionnaires between genders and the radiographic scale. Higher knee OA x-ray grade were associated with worse clinical outcome: for women, higher scores for the WOMAC pain, function and final scores and lower scores in the SF-36 final score; in men, lower SF-36 overall and physical domains scores. Gender differences were found in all clinical scores that were tested, with women having worse clinical scores for similar radiographic grading (p values <0.001). Knee radiographs for OA have an important role in the clinical evaluation of the patient. Patients with higher levels of knee OA in x-ray have a higher probability of having a worse clinical score in the WOMAC and SF-36 scores. The gender differences suggest that for similar knee OA x-ray grade, women's clinical scores are lower. NCT00767780.
- 22 January 2015
- Published by Springer Nature in Clinical Rheumatology
- Vol. 34 (11) , 1955-1960
The correlation between radiographic knee OA and clinical symptoms—do we know everything?
This study aims to evaluate the correlations between common clinical osteoarthritis (OA) diagnostic tools in order to determine the value of each. A secondary goal was to investigate the influence of gender differences on the findings. Five hundred and eighteen patients with knee OA were evaluated using the Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire, short form 36 (SF-36) Health Survey, and plain radiographs. Analysis of variance (ANOVA) was used to compare the different domains of the WOMAC and SF-36 questionnaires between genders and the radiographic scale. Higher knee OA x-ray grade were associated with worse clinical outcome: for women, higher scores for the WOMAC pain, function and final scores and lower scores in the SF-36 final score; in men, lower SF-36 overall and physical domains scores. Gender differences were found in all clinical scores that were tested, with women having worse clinical scores for similar radiographic grading (p values <0.001). Knee radiographs for OA have an important role in the clinical evaluation of the patient. Patients with higher levels of knee OA in x-ray have a higher probability of having a worse clinical score in the WOMAC and SF-36 scores. The gender differences suggest that for similar knee OA x-ray grade, women's clinical scores are lower. NCT00767780.
- 1 March 2014
- Published by Elsevier in Osteoarthritis and Cartilage
- Vol. 22 (3) , 457-463
Novel classification of knee osteoarthritis severity based on spatiotemporal gait analysis
- 1 March 2014
- Published by Elsevier in Osteoarthritis and Cartilage
- Vol. 22 (3) , 457-463
Novel classification of knee osteoarthritis severity based on spatiotemporal gait analysis