M. Liebergall - Academia.edu (original) (raw)
Papers by M. Liebergall
The Journal of cardiovascular surgery
Thrombosis of the axillary vein occurred in two patients following creation of an arteriovenous f... more Thrombosis of the axillary vein occurred in two patients following creation of an arteriovenous fistula for hemodialysis. The thrombosis developed before the fistula was used for dialysis, and was demonstrated by venography. Treatment in both cases involved anticoagulant therapy and ligation of the fistula; both patients experienced relief of pain and swelling, although the collateral venous congestion remained unchanged. This complication of arteriovenous fistula creation has not been previously described, probably because thrombosis does not usually occur in a high venous flow state.
With obesity on the rise in Israel, most of the medical staff will probably encounter the unique ... more With obesity on the rise in Israel, most of the medical staff will probably encounter the unique challenges that result from the pathophysiological changes in this population. Morbid obesity is a chronic disease manifesting itself in a steady and slow-progressive increase in body weight. Currently, BMI is considered the best score for morbid obesity definition and it is calculated by dividing the body weight (kgs) in body surface area (m2). The score for morbid obesity is above 40 kg/m2 and has many systemic implications such as hypertension, diabetes, cardiovascular changes, especially it effects the musculoskeletal system. Complex multiple trauma in morbid obesity patients present a challenge throughout all stages of treatment: assessment of injury, preliminary care, and definitive surgical approach. In the last two years five morbid obese patients (all weighted more than 150 kgs) sustained various degrees of high-energy multiple-trauma and were operated on in our institution. The...
Trauma Surgery & Acute Care Open, 2016
Background Our hypothesis in this study was that the outcome of patients with femur fractures wou... more Background Our hypothesis in this study was that the outcome of patients with femur fractures would be favorable in a level I trauma center (LITC). Methods A prospective multicenter cohort study. 5 LITC and 6 regional (level II) trauma centers (RTCs) were enrolled to participate in the study. A total of 238 patients suffering from a femoral fracture were recruited to the study. 125 patients were treated in LITCs and 113 in RTCs. Data were extracted from the emergency medical services ambulances, emergency department records, patient hospitalization and discharge records, operating room records, and the national trauma registry (for LITCs). A study questionnaire was administered to all participating patients at discharge, 6 weeks and 6 months postoperatively. The following parameters were studied: mechanism of injury, time from injury to the hospital, Injury Severity Score, classification of femoral fracture, additional injuries, medical history, time to surgery, implant type, skill level of the surgical team, type of anesthesia, length of stay and intensive care unit (ICU) stay, postoperative and intraoperative complications and mortality. Results There was a significant difference in the modality of patient transfer between the 2 study groups-with the LITC receiving more patients transported by helicopters or medical intensive care. Time to surgery from admission was shorter in the LITC. Length of stay, ICU stay, and mortality were similar. In the LITCs, 47% of the procedures were performed by residents without the supervision of an attending surgeon, and in the RTCs 79% of the procedures were performed with an senior orthopaedic surgeon. Intraoperative and immediate complication rates were similar among the 2 groups. Conclusions A femoral shaft fracture can be successfully treated in an LITC and RTC in the state of Israel. Both research and policy implementation works are required. Also, a more detailed outcome analysis and triage criteria for emergency are desired. Level of evidence II.
Navigation and MIS in Orthopedic Surgery
International Journal of Computer Assisted Radiology and Surgery, 2011
Objective The most commonly used imaging device for assessment of fracture reduction is the two-d... more Objective The most commonly used imaging device for assessment of fracture reduction is the two-dimensional X-ray fluoroscope. Two recently introduced 3D fluoroscopic devices, the Siremobil ISO-C3D (Siemens) and the C-InSight (Mazor Surgical Technologies), enable the surgeon to obtain spatial information for the assessment of articular reduction and hardware placement. The purpose of this study was to assess the reliability and accuracy of these two 3D fluoroscopic systems in measuring articular reduction in a cadaveric tibial plateau fracture. Methods Six cadaveric knee specimens were osteotomized at the lateral tibial plateau and fixed with a maximal articular step-off of 0, 1, 2.5, 5 and 7.5 mm. Each specimen was scanned 10 times with two 3D fluoroscopes, the Siremobil ISO-C3D and the C-InSight. The resulting images were reformatted and interpreted for articular displacements at four different locations at the plateau level and were compared with high-resolution CT scans by an independent observer.
American journal of orthopedics (Belle Mead, N.J.), 1998
Our experience with 10 patients who suffered midshaft fractures of the femur and injuries to thei... more Our experience with 10 patients who suffered midshaft fractures of the femur and injuries to their ipsilateral hips has resulted in a treatment protocol that we believe can avoid unnecessary complications. The surgical protocol is a three-stage procedure based on (1) intramedullary nailing of the femur with interlocking for preserving the anatomic length and rotation of the femur; (2) treatment of the hip joint injury by means of open reduction and internal fixation of the acetabular fracture and/or reduction and fixation of the fractured femoral neck; and (3) repair of the extensor mechanism. Eight patients received this treatment and had fast recoveries. Union of the femoral fracture and full range of motion of the knee joint were observed within 3 months. In contrast, two patients who had received different surgical treatment had incomplete functional recoveries. This study offers a treatment protocol for ipsilateral disruption of the extensor mechanism, hip joint injury, and mid...
Harefuah, Jan 15, 1989
During the past 5 years 10 patients suffering from cauda equina syndrome as a result of prolapsed... more During the past 5 years 10 patients suffering from cauda equina syndrome as a result of prolapsed disc were treated surgically. Although considerable time had elapsed between the onset of symptoms and the operation, most of the patients improved, at least partially. The syndrome is a rare complication of a common condition of the lower spine. Awareness of its possibility and identification of the early clinical picture are essential. An accurate history and detailed physical examination are the most important factors in early diagnosis. In 5 women and 4 men, who ranged in age from 28-60 and averaged 41 years, the disks involved were L5-S1 in 6, L4-L5 in 2 and L1-T12 in 1 case. Persistent disability was found in most of the patients, including 4 with bladder and 4 with sexual dysfunction. In 7 there was residual sensory loss and in 5 some degree of motor weakness. Earlier surgical treatment seems to be the most effective method for improving the results of treatment.
PURPOSE OF THE STUDYThe treatment of long bone diaphyseal fracture-nonunion is challenging. While... more PURPOSE OF THE STUDYThe treatment of long bone diaphyseal fracture-nonunion is challenging. While taking into account biological needs, a stable mechanical environment is pertinent for fracture healing. This work aims at evaluating the surgical management of stubborn ununited fractures using orthogonal double plating of diaphyseal fractures with limited periosteal stripping and soft tissue dissection.PATIENTS AND METHODSRetrospective analysis in a level I trauma center. Between the years 2007-2009, 22 patients were treated with double plating due to nonunion of long bone fractures. Long bones included three clavicles, six humeri, three femora, seven ulnae, two tibiae and one radius. The mean period between index procedures (if existed) and revision procedures was 53.35 weeks (range 6 months-3 years). The same surgical technique, independent on the anatomical location was utilized. Perioperative intravenous antibiotics were withheld until intraoperative cultures were obtained in all ...
Introduction: Several factors render plain X-ray radiographs of the hip unsuitable for bone miner... more Introduction: Several factors render plain X-ray radiographs of the hip unsuitable for bone mineral density measurements, mainly variability in X-ray exposure levels and soft tissue surrounding the bone. We present modification of proximal femur digital radiographs to compensate for these interfering factors. Methods: The study population consisted of 99 women, in three groups: 1 – elderly, sustaining a fracture of the neck of the femur. 2 – elderly, without a fracture. 3 – young. Each patient’s hip was radiographed with a brass step-wedge for standard reference. Dual-Energy X-ray Absorptiometry (DEXA) of the same hip was performed. On each radiograph, Regions Of Interest (ROIs) of the proximal femur were determined in concordance with ROI of the DEXA, together with three soft tissue regions surrounding the bone. Mean gray level was measured for each ROI. Results: The difference in gray level of the ROI within the proximal femur was not statistically significant between the groups. ...
International Journal of Computer Assisted Radiology and Surgery, 2015
The aim of orthopedic trauma surgery is to restore the anatomy and function of displaced bone fra... more The aim of orthopedic trauma surgery is to restore the anatomy and function of displaced bone fragments to support osteosynthesis. For complex cases, including pelvic bone and multi-fragment femoral neck and distal radius fractures, preoperative planning with a CT scan is indicated. The planning consists of (1) fracture reduction-determining the locations and anatomical sites of origin of the fractured bone fragments and (2) fracture fixation-selecting and placing fixation screws and plates. The current bone fragment manipulation, hardware selection, and positioning processes based on 2D slices and a computer mouse are time-consuming and require a technician.
The Journal of Hand Surgery, 2010
The hypothesis of this study was that more stable fixation of acute scaphoid fractures may be ach... more The hypothesis of this study was that more stable fixation of acute scaphoid fractures may be achieved by a screw placed perpendicular to the fracture plane than along the long axis of the scaphoid, as previously suggested. We examined this assumption on different fracture patterns using a finite element analysis model. Methods A computed tomography scan of an intact scaphoid of a young man provided the data set for all fracture models. We used semiautomatic segmentation to create 3-dimensional computer models of the 3 simple fracture configurations: oblique, transverse waist, and proximal fractures, according to the Herbert classification. Each fracture type was analyzed, using finite elements, for its biomechanical response to 2 types of virtual fixation: a screw placed either perpendicular to the fracture plane or centrally along the long axis of the scaphoid. We measured motion at the fracture plane (in millimeters) and strain in the screw threads (in millipascals). Results Considerably less motion was measured at the fracture plane with the perpendicular screw compared with the long axis screw, especially in the oblique-type fractures: (1) Herbert-type B1 oblique fracture mean motion of 0.05 mm (Ϯ0.03) for the perpendicular screw versus 0.28 mm (Ϯ0.05) for the long axis screw; (2) B2 transverse waist fracture mean motion of 0.06 mm (Ϯ0.03) for the perpendicular screw versus 0.18 mm (Ϯ0.06) for the long axis screw; and (3) B3 proximal fracture mean motion of 0.07 mm (Ϯ0.01) for the perpendicular screw versus 0.28 mm (Ϯ0.011) for the long axis screw. Higher strains were measured on the screw placed perpendicular to the fracture. Conclusions According to this model, higher fixation stability is achieved when the scaphoid is fixated perpendicular to the fracture. In transverse waist fractures, a centrally placed screw will also be perpendicular to the fracture, which explains the results of previous models.
Journal of Clinical Densitometry, 2001
The purpose of the present study was to evaluate a noninvasive method that utilizes optical proce... more The purpose of the present study was to evaluate a noninvasive method that utilizes optical processing to analyze the trabecular pattern on bone radiographs. The trabecular network on proximal femur radiographs of 17 intact cadaveric femora was analyzed by optical Fourier transform, yielding a trabecular bone index (TBI) at several locations. The bone mineral density (BMD) of the proximal femur was measured by dual X-ray absorptiometry. Dimensions of the proximal femur were obtained from the radiograph. The bones were fractured in a "fall configuration" to yield the fracture load. A multiple regression model, combining only radiograph-derived parameters-bone dimensions and the TBI at the intertrochanteric region and at the greater trochanter-yielded a correlation of 0.938 with the fracture load. A model combining the BMD at the greater trochanter and at the neck yielded a correlation of 0.928 with the fracture load. When all the variables were introduced into a combined analysis, the correlation with the fracture load was 0.973. The TBI obtained by optical processing of the trabecular bone pattern on femoral radiographs together with bone dimensions derived from these radiographs may serve as an effective estimate for hip fracture risk.
Foot & Ankle International, 1998
Percutaneous axial extensometers were mounted on the medial cortex of the midtibial diaphysis in ... more Percutaneous axial extensometers were mounted on the medial cortex of the midtibial diaphysis in seven male volunteers and the effect of three different shoes on in vivo peak-to-peak axial compression-tension strains measured during dynamic loading. Zohar shoes had lower axial strains and strain rates during treadmill walking than Nike Air Max running shoes or Israeli infantry boots. During running on a running track, there was no statistically significant difference between the axial strains or strain rates between the shoes tested. Shoe gear can modify tibial strains and strain rates that contribute to the development of tibial stress fractures.
Foot & Ankle International, 1996
The study was conducted to test the hypothesis that alterations in shoe gear can affect tibial st... more The study was conducted to test the hypothesis that alterations in shoe gear can affect tibial strains in the human during dynamic loading. Rosette strain gauges were mounted on the medial border of the mid-diaphysis in two human subjects with a new strain gauge bonding technique using methyl methacrylate. Strain measurements were made at this site, the most frequent location for stress fractures in the Israeli Army during treadmill walking and free running while wearing various sport shoes (Rockport ProWalkers and New Balance NBX 900) and army boots (light Israeli infantry, double layered sole Israeli infantry, and Zohar infantry boots). Data were analyzed for only one of the subjects because strain gauge bonding was found to be inadequate at the time of surgical removal in the other subject. No single shoe lowered both the principal tibial compression and tensile strains, and the shear strains. The Zohar boot had the lowest principal compression strains during treadmill walking an...
Clinical Infectious Diseases, 2003
We report 3 cases of Brucella melitensis infection of prosthetic hips and knees, and we summarize... more We report 3 cases of Brucella melitensis infection of prosthetic hips and knees, and we summarize data about 4 cases reported in the literature. Six of the 7 affected patients were men. The median duration from prosthesis implantation to the onset of symptoms was 38.7 months. Five patients had only local symptoms. Preoperative joint aspirates yielded negative culture results for 3 patients, and blood culture results were negative for 6 patients. Excisional arthroplasty was the initial intervention for 3 patients. Three others responded well to medical therapy alone. One patient had relapse while receiving tetracycline and underwent total hip replacement. All patients were treated with combined antibiotic therapy for 6 weeks to 19 months. All had favorable long-term responses. The 3 patients we treated underwent a 2-staged resection arthroplasty. Antibiotics alone can be used to treat Brucella prosthetic joint infection, but loosening of the joint and clinical or microbiological failure must be treated with a 2-staged excisional arthroplasty and 3 months of treatment with doxycycline and rifampicin.
Introduction: Non union of the humerus in the ostoeportic bone is a great challenge for the ortho... more Introduction: Non union of the humerus in the ostoeportic bone is a great challenge for the orthopedic surgeon. The non weight bearing nature of this bone together with extreme osteoporosis seen in the elderly had rendered a high degree of failure in different modes of internal fixation of established humeral non union. Tantalum is a trabecullar metal with biomechanical properties similar to bone with a high modulus of elasticity and low rigidity. It is proved both in vitro and in vivo to induce excellent bone and vascular in growth and have been used successfully treating other application in orthopedics. We have introduced the tantalum rod for the treatment of humeral non union in the elderly. Patients and Methods: Six patients with humeral non-union were selected for tantalum rod implantations. All were above 60 years old. All patients had established non and 4 had failures after previous osteosynthesis. The surgical technique was exploration of the fracture site via a posterior ...
Bone, 1995
In this study, the correlation between the mineralization of healing bone defects and the osteoge... more In this study, the correlation between the mineralization of healing bone defects and the osteogenic capacity of the serum was tested in rats. The purpose of the study was to test the hypothesis that during callus formation, some serum factors are consumed. The bone defects in the tibia contained two different implant types, and all sustained juxta-implant fractures. One implant type was the coral Poriles and the other was its recrystallized version (Interpore-200), which exhibit different mineralization rates during fracture healing. Use of these two implant types permitted generation of an expanded mineralization spectrum suitable for regression analysis. Mineralization was assessed by measuring the mineral content change (MCC) using dual-energy X-ray absorptiometry. Osteogenic capacity of sera of the implanted rats was assessed by its ability to increase specific alkaline phosphatase (ALP) activity in stromal cell cultures. The l\ICC was followed for 5 weeks in the Porites and Interpore-200 implants, and it was found that the MCC in Interpore-200 implants exceeded that of the Porites implants. Thus, the two implant types generated a wide mineralization spectrum. Induction of ALP in stromal cell culture was lower for sera deriwd from rats implanted with Interpore-200 than for sera derived from rats implanted with Porites. Two weeks after implantation, the change in serum ALP induction correlated inversely with the MCC of bone defects. This indicates that during callus formation, the mineralization rate is reciprocally related to the serum osteogenic capacity. The decreased serum osteogenic capacity may be interpreted by the hypothesis that callus formation consumes certain serum osteogenic factors.
The Journal of cardiovascular surgery
Thrombosis of the axillary vein occurred in two patients following creation of an arteriovenous f... more Thrombosis of the axillary vein occurred in two patients following creation of an arteriovenous fistula for hemodialysis. The thrombosis developed before the fistula was used for dialysis, and was demonstrated by venography. Treatment in both cases involved anticoagulant therapy and ligation of the fistula; both patients experienced relief of pain and swelling, although the collateral venous congestion remained unchanged. This complication of arteriovenous fistula creation has not been previously described, probably because thrombosis does not usually occur in a high venous flow state.
With obesity on the rise in Israel, most of the medical staff will probably encounter the unique ... more With obesity on the rise in Israel, most of the medical staff will probably encounter the unique challenges that result from the pathophysiological changes in this population. Morbid obesity is a chronic disease manifesting itself in a steady and slow-progressive increase in body weight. Currently, BMI is considered the best score for morbid obesity definition and it is calculated by dividing the body weight (kgs) in body surface area (m2). The score for morbid obesity is above 40 kg/m2 and has many systemic implications such as hypertension, diabetes, cardiovascular changes, especially it effects the musculoskeletal system. Complex multiple trauma in morbid obesity patients present a challenge throughout all stages of treatment: assessment of injury, preliminary care, and definitive surgical approach. In the last two years five morbid obese patients (all weighted more than 150 kgs) sustained various degrees of high-energy multiple-trauma and were operated on in our institution. The...
Trauma Surgery & Acute Care Open, 2016
Background Our hypothesis in this study was that the outcome of patients with femur fractures wou... more Background Our hypothesis in this study was that the outcome of patients with femur fractures would be favorable in a level I trauma center (LITC). Methods A prospective multicenter cohort study. 5 LITC and 6 regional (level II) trauma centers (RTCs) were enrolled to participate in the study. A total of 238 patients suffering from a femoral fracture were recruited to the study. 125 patients were treated in LITCs and 113 in RTCs. Data were extracted from the emergency medical services ambulances, emergency department records, patient hospitalization and discharge records, operating room records, and the national trauma registry (for LITCs). A study questionnaire was administered to all participating patients at discharge, 6 weeks and 6 months postoperatively. The following parameters were studied: mechanism of injury, time from injury to the hospital, Injury Severity Score, classification of femoral fracture, additional injuries, medical history, time to surgery, implant type, skill level of the surgical team, type of anesthesia, length of stay and intensive care unit (ICU) stay, postoperative and intraoperative complications and mortality. Results There was a significant difference in the modality of patient transfer between the 2 study groups-with the LITC receiving more patients transported by helicopters or medical intensive care. Time to surgery from admission was shorter in the LITC. Length of stay, ICU stay, and mortality were similar. In the LITCs, 47% of the procedures were performed by residents without the supervision of an attending surgeon, and in the RTCs 79% of the procedures were performed with an senior orthopaedic surgeon. Intraoperative and immediate complication rates were similar among the 2 groups. Conclusions A femoral shaft fracture can be successfully treated in an LITC and RTC in the state of Israel. Both research and policy implementation works are required. Also, a more detailed outcome analysis and triage criteria for emergency are desired. Level of evidence II.
Navigation and MIS in Orthopedic Surgery
International Journal of Computer Assisted Radiology and Surgery, 2011
Objective The most commonly used imaging device for assessment of fracture reduction is the two-d... more Objective The most commonly used imaging device for assessment of fracture reduction is the two-dimensional X-ray fluoroscope. Two recently introduced 3D fluoroscopic devices, the Siremobil ISO-C3D (Siemens) and the C-InSight (Mazor Surgical Technologies), enable the surgeon to obtain spatial information for the assessment of articular reduction and hardware placement. The purpose of this study was to assess the reliability and accuracy of these two 3D fluoroscopic systems in measuring articular reduction in a cadaveric tibial plateau fracture. Methods Six cadaveric knee specimens were osteotomized at the lateral tibial plateau and fixed with a maximal articular step-off of 0, 1, 2.5, 5 and 7.5 mm. Each specimen was scanned 10 times with two 3D fluoroscopes, the Siremobil ISO-C3D and the C-InSight. The resulting images were reformatted and interpreted for articular displacements at four different locations at the plateau level and were compared with high-resolution CT scans by an independent observer.
American journal of orthopedics (Belle Mead, N.J.), 1998
Our experience with 10 patients who suffered midshaft fractures of the femur and injuries to thei... more Our experience with 10 patients who suffered midshaft fractures of the femur and injuries to their ipsilateral hips has resulted in a treatment protocol that we believe can avoid unnecessary complications. The surgical protocol is a three-stage procedure based on (1) intramedullary nailing of the femur with interlocking for preserving the anatomic length and rotation of the femur; (2) treatment of the hip joint injury by means of open reduction and internal fixation of the acetabular fracture and/or reduction and fixation of the fractured femoral neck; and (3) repair of the extensor mechanism. Eight patients received this treatment and had fast recoveries. Union of the femoral fracture and full range of motion of the knee joint were observed within 3 months. In contrast, two patients who had received different surgical treatment had incomplete functional recoveries. This study offers a treatment protocol for ipsilateral disruption of the extensor mechanism, hip joint injury, and mid...
Harefuah, Jan 15, 1989
During the past 5 years 10 patients suffering from cauda equina syndrome as a result of prolapsed... more During the past 5 years 10 patients suffering from cauda equina syndrome as a result of prolapsed disc were treated surgically. Although considerable time had elapsed between the onset of symptoms and the operation, most of the patients improved, at least partially. The syndrome is a rare complication of a common condition of the lower spine. Awareness of its possibility and identification of the early clinical picture are essential. An accurate history and detailed physical examination are the most important factors in early diagnosis. In 5 women and 4 men, who ranged in age from 28-60 and averaged 41 years, the disks involved were L5-S1 in 6, L4-L5 in 2 and L1-T12 in 1 case. Persistent disability was found in most of the patients, including 4 with bladder and 4 with sexual dysfunction. In 7 there was residual sensory loss and in 5 some degree of motor weakness. Earlier surgical treatment seems to be the most effective method for improving the results of treatment.
PURPOSE OF THE STUDYThe treatment of long bone diaphyseal fracture-nonunion is challenging. While... more PURPOSE OF THE STUDYThe treatment of long bone diaphyseal fracture-nonunion is challenging. While taking into account biological needs, a stable mechanical environment is pertinent for fracture healing. This work aims at evaluating the surgical management of stubborn ununited fractures using orthogonal double plating of diaphyseal fractures with limited periosteal stripping and soft tissue dissection.PATIENTS AND METHODSRetrospective analysis in a level I trauma center. Between the years 2007-2009, 22 patients were treated with double plating due to nonunion of long bone fractures. Long bones included three clavicles, six humeri, three femora, seven ulnae, two tibiae and one radius. The mean period between index procedures (if existed) and revision procedures was 53.35 weeks (range 6 months-3 years). The same surgical technique, independent on the anatomical location was utilized. Perioperative intravenous antibiotics were withheld until intraoperative cultures were obtained in all ...
Introduction: Several factors render plain X-ray radiographs of the hip unsuitable for bone miner... more Introduction: Several factors render plain X-ray radiographs of the hip unsuitable for bone mineral density measurements, mainly variability in X-ray exposure levels and soft tissue surrounding the bone. We present modification of proximal femur digital radiographs to compensate for these interfering factors. Methods: The study population consisted of 99 women, in three groups: 1 – elderly, sustaining a fracture of the neck of the femur. 2 – elderly, without a fracture. 3 – young. Each patient’s hip was radiographed with a brass step-wedge for standard reference. Dual-Energy X-ray Absorptiometry (DEXA) of the same hip was performed. On each radiograph, Regions Of Interest (ROIs) of the proximal femur were determined in concordance with ROI of the DEXA, together with three soft tissue regions surrounding the bone. Mean gray level was measured for each ROI. Results: The difference in gray level of the ROI within the proximal femur was not statistically significant between the groups. ...
International Journal of Computer Assisted Radiology and Surgery, 2015
The aim of orthopedic trauma surgery is to restore the anatomy and function of displaced bone fra... more The aim of orthopedic trauma surgery is to restore the anatomy and function of displaced bone fragments to support osteosynthesis. For complex cases, including pelvic bone and multi-fragment femoral neck and distal radius fractures, preoperative planning with a CT scan is indicated. The planning consists of (1) fracture reduction-determining the locations and anatomical sites of origin of the fractured bone fragments and (2) fracture fixation-selecting and placing fixation screws and plates. The current bone fragment manipulation, hardware selection, and positioning processes based on 2D slices and a computer mouse are time-consuming and require a technician.
The Journal of Hand Surgery, 2010
The hypothesis of this study was that more stable fixation of acute scaphoid fractures may be ach... more The hypothesis of this study was that more stable fixation of acute scaphoid fractures may be achieved by a screw placed perpendicular to the fracture plane than along the long axis of the scaphoid, as previously suggested. We examined this assumption on different fracture patterns using a finite element analysis model. Methods A computed tomography scan of an intact scaphoid of a young man provided the data set for all fracture models. We used semiautomatic segmentation to create 3-dimensional computer models of the 3 simple fracture configurations: oblique, transverse waist, and proximal fractures, according to the Herbert classification. Each fracture type was analyzed, using finite elements, for its biomechanical response to 2 types of virtual fixation: a screw placed either perpendicular to the fracture plane or centrally along the long axis of the scaphoid. We measured motion at the fracture plane (in millimeters) and strain in the screw threads (in millipascals). Results Considerably less motion was measured at the fracture plane with the perpendicular screw compared with the long axis screw, especially in the oblique-type fractures: (1) Herbert-type B1 oblique fracture mean motion of 0.05 mm (Ϯ0.03) for the perpendicular screw versus 0.28 mm (Ϯ0.05) for the long axis screw; (2) B2 transverse waist fracture mean motion of 0.06 mm (Ϯ0.03) for the perpendicular screw versus 0.18 mm (Ϯ0.06) for the long axis screw; and (3) B3 proximal fracture mean motion of 0.07 mm (Ϯ0.01) for the perpendicular screw versus 0.28 mm (Ϯ0.011) for the long axis screw. Higher strains were measured on the screw placed perpendicular to the fracture. Conclusions According to this model, higher fixation stability is achieved when the scaphoid is fixated perpendicular to the fracture. In transverse waist fractures, a centrally placed screw will also be perpendicular to the fracture, which explains the results of previous models.
Journal of Clinical Densitometry, 2001
The purpose of the present study was to evaluate a noninvasive method that utilizes optical proce... more The purpose of the present study was to evaluate a noninvasive method that utilizes optical processing to analyze the trabecular pattern on bone radiographs. The trabecular network on proximal femur radiographs of 17 intact cadaveric femora was analyzed by optical Fourier transform, yielding a trabecular bone index (TBI) at several locations. The bone mineral density (BMD) of the proximal femur was measured by dual X-ray absorptiometry. Dimensions of the proximal femur were obtained from the radiograph. The bones were fractured in a "fall configuration" to yield the fracture load. A multiple regression model, combining only radiograph-derived parameters-bone dimensions and the TBI at the intertrochanteric region and at the greater trochanter-yielded a correlation of 0.938 with the fracture load. A model combining the BMD at the greater trochanter and at the neck yielded a correlation of 0.928 with the fracture load. When all the variables were introduced into a combined analysis, the correlation with the fracture load was 0.973. The TBI obtained by optical processing of the trabecular bone pattern on femoral radiographs together with bone dimensions derived from these radiographs may serve as an effective estimate for hip fracture risk.
Foot & Ankle International, 1998
Percutaneous axial extensometers were mounted on the medial cortex of the midtibial diaphysis in ... more Percutaneous axial extensometers were mounted on the medial cortex of the midtibial diaphysis in seven male volunteers and the effect of three different shoes on in vivo peak-to-peak axial compression-tension strains measured during dynamic loading. Zohar shoes had lower axial strains and strain rates during treadmill walking than Nike Air Max running shoes or Israeli infantry boots. During running on a running track, there was no statistically significant difference between the axial strains or strain rates between the shoes tested. Shoe gear can modify tibial strains and strain rates that contribute to the development of tibial stress fractures.
Foot & Ankle International, 1996
The study was conducted to test the hypothesis that alterations in shoe gear can affect tibial st... more The study was conducted to test the hypothesis that alterations in shoe gear can affect tibial strains in the human during dynamic loading. Rosette strain gauges were mounted on the medial border of the mid-diaphysis in two human subjects with a new strain gauge bonding technique using methyl methacrylate. Strain measurements were made at this site, the most frequent location for stress fractures in the Israeli Army during treadmill walking and free running while wearing various sport shoes (Rockport ProWalkers and New Balance NBX 900) and army boots (light Israeli infantry, double layered sole Israeli infantry, and Zohar infantry boots). Data were analyzed for only one of the subjects because strain gauge bonding was found to be inadequate at the time of surgical removal in the other subject. No single shoe lowered both the principal tibial compression and tensile strains, and the shear strains. The Zohar boot had the lowest principal compression strains during treadmill walking an...
Clinical Infectious Diseases, 2003
We report 3 cases of Brucella melitensis infection of prosthetic hips and knees, and we summarize... more We report 3 cases of Brucella melitensis infection of prosthetic hips and knees, and we summarize data about 4 cases reported in the literature. Six of the 7 affected patients were men. The median duration from prosthesis implantation to the onset of symptoms was 38.7 months. Five patients had only local symptoms. Preoperative joint aspirates yielded negative culture results for 3 patients, and blood culture results were negative for 6 patients. Excisional arthroplasty was the initial intervention for 3 patients. Three others responded well to medical therapy alone. One patient had relapse while receiving tetracycline and underwent total hip replacement. All patients were treated with combined antibiotic therapy for 6 weeks to 19 months. All had favorable long-term responses. The 3 patients we treated underwent a 2-staged resection arthroplasty. Antibiotics alone can be used to treat Brucella prosthetic joint infection, but loosening of the joint and clinical or microbiological failure must be treated with a 2-staged excisional arthroplasty and 3 months of treatment with doxycycline and rifampicin.
Introduction: Non union of the humerus in the ostoeportic bone is a great challenge for the ortho... more Introduction: Non union of the humerus in the ostoeportic bone is a great challenge for the orthopedic surgeon. The non weight bearing nature of this bone together with extreme osteoporosis seen in the elderly had rendered a high degree of failure in different modes of internal fixation of established humeral non union. Tantalum is a trabecullar metal with biomechanical properties similar to bone with a high modulus of elasticity and low rigidity. It is proved both in vitro and in vivo to induce excellent bone and vascular in growth and have been used successfully treating other application in orthopedics. We have introduced the tantalum rod for the treatment of humeral non union in the elderly. Patients and Methods: Six patients with humeral non-union were selected for tantalum rod implantations. All were above 60 years old. All patients had established non and 4 had failures after previous osteosynthesis. The surgical technique was exploration of the fracture site via a posterior ...
Bone, 1995
In this study, the correlation between the mineralization of healing bone defects and the osteoge... more In this study, the correlation between the mineralization of healing bone defects and the osteogenic capacity of the serum was tested in rats. The purpose of the study was to test the hypothesis that during callus formation, some serum factors are consumed. The bone defects in the tibia contained two different implant types, and all sustained juxta-implant fractures. One implant type was the coral Poriles and the other was its recrystallized version (Interpore-200), which exhibit different mineralization rates during fracture healing. Use of these two implant types permitted generation of an expanded mineralization spectrum suitable for regression analysis. Mineralization was assessed by measuring the mineral content change (MCC) using dual-energy X-ray absorptiometry. Osteogenic capacity of sera of the implanted rats was assessed by its ability to increase specific alkaline phosphatase (ALP) activity in stromal cell cultures. The l\ICC was followed for 5 weeks in the Porites and Interpore-200 implants, and it was found that the MCC in Interpore-200 implants exceeded that of the Porites implants. Thus, the two implant types generated a wide mineralization spectrum. Induction of ALP in stromal cell culture was lower for sera deriwd from rats implanted with Interpore-200 than for sera derived from rats implanted with Porites. Two weeks after implantation, the change in serum ALP induction correlated inversely with the MCC of bone defects. This indicates that during callus formation, the mineralization rate is reciprocally related to the serum osteogenic capacity. The decreased serum osteogenic capacity may be interpreted by the hypothesis that callus formation consumes certain serum osteogenic factors.