O. Lubovsky - Academia.edu (original) (raw)

Papers by O. Lubovsky

Research paper thumbnail of Gait assessment of patients with spontaneous osteonecrosis of the knee

Osteoarthritis and Cartilage, 2016

Research paper thumbnail of A novel self-care biomechanical treatment for obese patients with knee osteoarthritis

International Journal of Rheumatic Diseases, 2015

Aim: To examine the effect of a novel biomechanical, home-based, gait training device on gait pat... more Aim: To examine the effect of a novel biomechanical, home-based, gait training device on gait patterns of obese individuals with knee OA. Methods: This was a retrospective analysis of 105 (32 males, 73 females) obese (body mass index > 30 kg/ m 2) subjects with knee OA who completed a 12-month program using a biomechanical gait training device and performing specified exercises. They underwent a computerized gait test to characterize spatiotemporal parameters, and completed the Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire and Short Form-36 (SF-36) Health Survey. They were then fitted with biomechanical gait training devices and began a home-based exercise program. Gait patterns and clinical symptoms were assessed after 3 and 12 months of therapy. Results: Each gait parameter improved significantly at 3 months and more so at 12 months (P = 0.03 overall). Gait velocity increased by 11.8% and by 16.1%, respectively. Single limb support of the more symptomatic knee increased by 2.5% and by 3.6%, respectively. There was a significant reduction in pain, stiffness and functional limitation at 3 months (P < 0.001 for each) that further improved at 12 months. Pain decreased by 34.7% and by 45.7%, respectively. Functional limitation decreased by 35.0% and by 44.7%, respectively. Both the Physical and Mental Scales of the SF-36 increased significantly (P < 0.001) at 3 months and more so following 12 months. Conclusions: Obese subjects with knee OA who complied with a home-based exercise program using a biomechanical gait training device demonstrated a significant improvement in gait patterns and clinical symptoms after 3 months, followed by an additional improvement after 12 months.

Research paper thumbnail of Acetabular orientation: anatomical and functional measurement

International Journal of Computer Assisted Radiology and Surgery, 2011

Research paper thumbnail of Early diagnosis of occult hip fractures

Injury, 2005

OBJECTIVE We compared Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) in diagno... more OBJECTIVE We compared Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) in diagnosis of a painful hip in elderly patients after trauma. We report on accuracy, efficiency and benefits. DESIGN We assessed 13 patients, average age 73 years, after fall with plain X-rays showing no evidence of fracture. There were two groups: Group A (six patients) underwent CT and MRI; Group B underwent MRI only. RESULTS In Group A where all of the six patients underwent CT and MRI, four of the CT images resulted in misdiagnosis due to inaccuracy. In Group B where all the seven patients underwent only MRI, all the results were accurate and enabled a precise and fast diagnosis. CONCLUSIONS MRI was found to be a more accurate modality than CT scan for obtaining early diagnosis of occult hip fractures. These results point out the advantage of immediate MRI imaging in patients with occult hip fracture enabling a more effective treatment, a shorter hospitalisation period entailing decreased medical costs.

Research paper thumbnail of Functional and Anatomic Orientation of the Femoral Head

Clinical Orthopaedics & Related Research, 2011

Background Femoral neck geometry directly affects load transmission through the hip. Orientations... more Background Femoral neck geometry directly affects load transmission through the hip. Orientations may be described anatomically or using functional definitions that consider load transmission. Questions/purposes This study introduces and applies a new method for characterizing functional femoral orientation based on the distribution of subchondral bone density in the femoral head and compares it with orientation measures generated via established anatomic landmark-based methods. Both orientation methods then are used to characterize side-to-side symmetry of orientation and differences between men and women within the population. Patients and Methods A retrospective review of CT imaging data from 28 patients was performed. Anatomic orientation was determined using established two-dimensional and three-dimensional landmarking methods. Subchondral bone density maps were generated and used to define a density-weighted surface normal vector. Orientation angles generated by the three methods were compared, with side-to-side symmetry and differences between genders also investigated. Results The three methods measured substantially different angles for anteversion and neck-shaft angle. Weak correlations were found between anatomic and functional orientation measures for neck-shaft angle only. Conclusions Neck-shaft angles calculated using the functional orientation method corresponded well with previous in vivo loading data. An absence of strong correlation between functional and anatomic measures reinforces the concept that bone geometry is not solely responsible for determining loading of the femoral head. Level of Evidence Level II, Diagnostic Studies-Investigating a Diagnostic Test. See the Guidelines for Authors for a complete description of levels of evidence. One or more of the authors (DW) have received funding from Sunnybrook Research Institute. Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. Each author certifies that his or her institution approved the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.

Research paper thumbnail of Cervical collar

Research paper thumbnail of Acetabular orientation variability and symmetry based on CT scans of adults

International Journal of Computer Assisted Radiology and Surgery, 2010

Research paper thumbnail of The Effect of X-Ray Projection on the Measurement of Clavicular Fracture Displacement

Fractures of the clavicle are relatively common, occurring mostly in younger patients and have hi... more Fractures of the clavicle are relatively common, occurring mostly in younger patients and have historically been managed non-operatively. Recent studies have shown an advantage to surgical reduction and stabilisation of clavicle fractures with significant displacement. Currently, fracture displacement is measured using simple anterior-posterior two-dimensional x-rays of the clavicle. Since displacement can occur in all three-dimensions, however, evaluation of the amount displacement can be difficult and inaccurate. The purpose of this study was to determine the view that provides the most accurate assessment. Nine CT scans of acute displaced clavicle fractures were analysed with AmiraDEV5.2.2 Imaging software. Measurements for degrees of shortening and fracture displacement of the fracture clavicle were taken. Using a segmentation and manipulation module (ITK toolkit), five digitally reconstructed radiographs (DRRs) mimicking antero-posterior x-rays were created for every CT, with e...

Research paper thumbnail of Prognosticating Acetabular Fractures Using CT Analysis

Introduction: Displaced acetabular fractures occur in young adults as the result of high-energy t... more Introduction: Displaced acetabular fractures occur in young adults as the result of high-energy trauma. In a many cases, surgical reconstruction leads to excellent patient outcome [1]; however, it is recognized that some fracture patterns have worse prognoses than others. Current methods of analysis and classification of fractures are limited in their ability to predict functional outcome in acetabular fractures [2]. Previous CT based study of healthy acetabuli showed that measured bone density distributions corresponded with areas considered to be under the highest load (in agreement with Wolff’s Law, the concept that bone grows in response to mechanical loading). It is hypothesized that measurement of damage to the regions of highest mechanical load will give a better prediction of patient outcome than is currently available, allowing clinicians to improve treatment planning for patients with poor prognoses. This study aims: 1) to quantify initial damage to acetabular subchondral ...

Research paper thumbnail of Effect of a novel biomechanical treatment on pain, function and gait pattern in obese patients with knee osteoarthritis

Osteoarthritis and Cartilage, 2014

Research paper thumbnail of Early diagnosis of occult hip fractures

Injury, 2005

We compared Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) in diagnosis of a p... more We compared Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) in diagnosis of a painful hip in elderly patients after trauma. We report on accuracy, efficiency and benefits. We assessed 13 patients, average age 73 years, after fall with plain X-rays showing no evidence of fracture. There were two groups: Group A (six patients) underwent CT and MRI; Group B underwent MRI only. In Group A where all of the six patients underwent CT and MRI, four of the CT images resulted in misdiagnosis due to inaccuracy. In Group B where all the seven patients underwent only MRI, all the results were accurate and enabled a precise and fast diagnosis. MRI was found to be a more accurate modality than CT scan for obtaining early diagnosis of occult hip fractures. These results point out the advantage of immediate MRI imaging in patients with occult hip fracture enabling a more effective treatment, a shorter hospitalisation period entailing decreased medical costs.

Research paper thumbnail of Importance of the dome and posterior wall as evidenced by bone density mapping in the acetabulum

Clinical Biomechanics, 2011

Characterizing the distribution of bone density in the acetabulum is of importance in better unde... more Characterizing the distribution of bone density in the acetabulum is of importance in better understanding and guiding treatment for both osteoarthritis and trauma of the hip joint. This study aims to develop a highly automated method to quantify the pattern of subchondral bone density in the acetabulum using clinically identifiable regions. Subchondral acetabular bone density distribution maps were created bilaterally from 30 non-pathologic pelvic CT scans. The density maps were aligned orthogonal to the acetabular rim plane and divided into twelve zones. Average bone density was calculated in each of these zones and compared to investigate differences between regions within each acetabulum and between right and left sides in a given patient. In all patients, the zones corresponding to the dome and posterior wall of the acetabulum demonstrated significantly higher average bone densities than all other regions (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). Significant correlations (R=0.4 to 0.76, P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) were found between corresponding regions of the left and right sides in 10 of the 12 zones. The pattern of subchondral bone density distribution found in this study is consistent with previously observed bone density patterns in the acetabulum. Correspondence of right and left sides suggests that the distribution of loading on the acetabulum is similar on both sides in healthy individuals, though differences may exist in load sharing. Quantifying bone density patterns using zonal density map analysis may lead to a better understanding of the impact of traumatic injuries and progression of pathologic conditions in the hip joint.

Research paper thumbnail of Acetabular orientation variability and symmetry based on CT scans of adults

International Journal of Computer Assisted Radiology and Surgery, 2010

Purpose Understanding acetabular orientation is important in many orthopaedic procedures. Acetabu... more Purpose Understanding acetabular orientation is important in many orthopaedic procedures. Acetabular orientation, usually described by anteversion and abduction angles, has uncertain measurement variability in adult patients. The goals of this study are threefold: (1) to describe a new method for computing patient-specific abduction/anteversion angles from a single CT study based on the identification of anatomical landmarks and acetabular rim points; (2) to quantify the inaccuracies associated with landmark selection in computing the acetabular angles; and (3) to quantify the variability and symmetry of acetabular orientation. Methods A total of 25 CT studies from adult patients scanned for non-orthopaedic indications were retrospectively reviewed. The patients were randomly selected from the hospital's database. Inclusion criteria were adults 20-65 years of age. Acetabular landmark coordinates were identified by expert observers and tabulated in a spreadsheet. Two sets of calculations were done using the data: (1) computation of the abduction and anteversion for each patient, and (2) evaluation of the variability of measurements in the same individual by the same surgeon. The results were tabulated and summary statistics computed. Results This retrospective study showed that acetabular abduction and anteversion angles averaged 54 • and 17 • , respectively, in adults. A clinically significant intra-patient variability of >20 • was found. We also found that the right and left side rim plane orientation were significantly correlated, but were not always symmetric. Conclusion A new method of computing patient-specific abduction and anteversion angles from a CT study of the anterior pelvic plane and the left and right acetabular rim planes was reliable and accurate. We found that the acetabular rim plane can be reliably and accurately computed from identified points on the rim. The novelty of this work is that angular measurements are performed between planes on a 3-D model rather than lines on 2-D projections, as was done in the past.

Research paper thumbnail of Gait assessment of patients with spontaneous osteonecrosis of the knee

Osteoarthritis and Cartilage, 2016

Research paper thumbnail of A novel self-care biomechanical treatment for obese patients with knee osteoarthritis

International Journal of Rheumatic Diseases, 2015

Aim: To examine the effect of a novel biomechanical, home-based, gait training device on gait pat... more Aim: To examine the effect of a novel biomechanical, home-based, gait training device on gait patterns of obese individuals with knee OA. Methods: This was a retrospective analysis of 105 (32 males, 73 females) obese (body mass index > 30 kg/ m 2) subjects with knee OA who completed a 12-month program using a biomechanical gait training device and performing specified exercises. They underwent a computerized gait test to characterize spatiotemporal parameters, and completed the Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire and Short Form-36 (SF-36) Health Survey. They were then fitted with biomechanical gait training devices and began a home-based exercise program. Gait patterns and clinical symptoms were assessed after 3 and 12 months of therapy. Results: Each gait parameter improved significantly at 3 months and more so at 12 months (P = 0.03 overall). Gait velocity increased by 11.8% and by 16.1%, respectively. Single limb support of the more symptomatic knee increased by 2.5% and by 3.6%, respectively. There was a significant reduction in pain, stiffness and functional limitation at 3 months (P < 0.001 for each) that further improved at 12 months. Pain decreased by 34.7% and by 45.7%, respectively. Functional limitation decreased by 35.0% and by 44.7%, respectively. Both the Physical and Mental Scales of the SF-36 increased significantly (P < 0.001) at 3 months and more so following 12 months. Conclusions: Obese subjects with knee OA who complied with a home-based exercise program using a biomechanical gait training device demonstrated a significant improvement in gait patterns and clinical symptoms after 3 months, followed by an additional improvement after 12 months.

Research paper thumbnail of Acetabular orientation: anatomical and functional measurement

International Journal of Computer Assisted Radiology and Surgery, 2011

Research paper thumbnail of Early diagnosis of occult hip fractures

Injury, 2005

OBJECTIVE We compared Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) in diagno... more OBJECTIVE We compared Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) in diagnosis of a painful hip in elderly patients after trauma. We report on accuracy, efficiency and benefits. DESIGN We assessed 13 patients, average age 73 years, after fall with plain X-rays showing no evidence of fracture. There were two groups: Group A (six patients) underwent CT and MRI; Group B underwent MRI only. RESULTS In Group A where all of the six patients underwent CT and MRI, four of the CT images resulted in misdiagnosis due to inaccuracy. In Group B where all the seven patients underwent only MRI, all the results were accurate and enabled a precise and fast diagnosis. CONCLUSIONS MRI was found to be a more accurate modality than CT scan for obtaining early diagnosis of occult hip fractures. These results point out the advantage of immediate MRI imaging in patients with occult hip fracture enabling a more effective treatment, a shorter hospitalisation period entailing decreased medical costs.

Research paper thumbnail of Functional and Anatomic Orientation of the Femoral Head

Clinical Orthopaedics & Related Research, 2011

Background Femoral neck geometry directly affects load transmission through the hip. Orientations... more Background Femoral neck geometry directly affects load transmission through the hip. Orientations may be described anatomically or using functional definitions that consider load transmission. Questions/purposes This study introduces and applies a new method for characterizing functional femoral orientation based on the distribution of subchondral bone density in the femoral head and compares it with orientation measures generated via established anatomic landmark-based methods. Both orientation methods then are used to characterize side-to-side symmetry of orientation and differences between men and women within the population. Patients and Methods A retrospective review of CT imaging data from 28 patients was performed. Anatomic orientation was determined using established two-dimensional and three-dimensional landmarking methods. Subchondral bone density maps were generated and used to define a density-weighted surface normal vector. Orientation angles generated by the three methods were compared, with side-to-side symmetry and differences between genders also investigated. Results The three methods measured substantially different angles for anteversion and neck-shaft angle. Weak correlations were found between anatomic and functional orientation measures for neck-shaft angle only. Conclusions Neck-shaft angles calculated using the functional orientation method corresponded well with previous in vivo loading data. An absence of strong correlation between functional and anatomic measures reinforces the concept that bone geometry is not solely responsible for determining loading of the femoral head. Level of Evidence Level II, Diagnostic Studies-Investigating a Diagnostic Test. See the Guidelines for Authors for a complete description of levels of evidence. One or more of the authors (DW) have received funding from Sunnybrook Research Institute. Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. Each author certifies that his or her institution approved the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.

Research paper thumbnail of Cervical collar

Research paper thumbnail of Acetabular orientation variability and symmetry based on CT scans of adults

International Journal of Computer Assisted Radiology and Surgery, 2010

Research paper thumbnail of The Effect of X-Ray Projection on the Measurement of Clavicular Fracture Displacement

Fractures of the clavicle are relatively common, occurring mostly in younger patients and have hi... more Fractures of the clavicle are relatively common, occurring mostly in younger patients and have historically been managed non-operatively. Recent studies have shown an advantage to surgical reduction and stabilisation of clavicle fractures with significant displacement. Currently, fracture displacement is measured using simple anterior-posterior two-dimensional x-rays of the clavicle. Since displacement can occur in all three-dimensions, however, evaluation of the amount displacement can be difficult and inaccurate. The purpose of this study was to determine the view that provides the most accurate assessment. Nine CT scans of acute displaced clavicle fractures were analysed with AmiraDEV5.2.2 Imaging software. Measurements for degrees of shortening and fracture displacement of the fracture clavicle were taken. Using a segmentation and manipulation module (ITK toolkit), five digitally reconstructed radiographs (DRRs) mimicking antero-posterior x-rays were created for every CT, with e...

Research paper thumbnail of Prognosticating Acetabular Fractures Using CT Analysis

Introduction: Displaced acetabular fractures occur in young adults as the result of high-energy t... more Introduction: Displaced acetabular fractures occur in young adults as the result of high-energy trauma. In a many cases, surgical reconstruction leads to excellent patient outcome [1]; however, it is recognized that some fracture patterns have worse prognoses than others. Current methods of analysis and classification of fractures are limited in their ability to predict functional outcome in acetabular fractures [2]. Previous CT based study of healthy acetabuli showed that measured bone density distributions corresponded with areas considered to be under the highest load (in agreement with Wolff’s Law, the concept that bone grows in response to mechanical loading). It is hypothesized that measurement of damage to the regions of highest mechanical load will give a better prediction of patient outcome than is currently available, allowing clinicians to improve treatment planning for patients with poor prognoses. This study aims: 1) to quantify initial damage to acetabular subchondral ...

Research paper thumbnail of Effect of a novel biomechanical treatment on pain, function and gait pattern in obese patients with knee osteoarthritis

Osteoarthritis and Cartilage, 2014

Research paper thumbnail of Early diagnosis of occult hip fractures

Injury, 2005

We compared Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) in diagnosis of a p... more We compared Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) in diagnosis of a painful hip in elderly patients after trauma. We report on accuracy, efficiency and benefits. We assessed 13 patients, average age 73 years, after fall with plain X-rays showing no evidence of fracture. There were two groups: Group A (six patients) underwent CT and MRI; Group B underwent MRI only. In Group A where all of the six patients underwent CT and MRI, four of the CT images resulted in misdiagnosis due to inaccuracy. In Group B where all the seven patients underwent only MRI, all the results were accurate and enabled a precise and fast diagnosis. MRI was found to be a more accurate modality than CT scan for obtaining early diagnosis of occult hip fractures. These results point out the advantage of immediate MRI imaging in patients with occult hip fracture enabling a more effective treatment, a shorter hospitalisation period entailing decreased medical costs.

Research paper thumbnail of Importance of the dome and posterior wall as evidenced by bone density mapping in the acetabulum

Clinical Biomechanics, 2011

Characterizing the distribution of bone density in the acetabulum is of importance in better unde... more Characterizing the distribution of bone density in the acetabulum is of importance in better understanding and guiding treatment for both osteoarthritis and trauma of the hip joint. This study aims to develop a highly automated method to quantify the pattern of subchondral bone density in the acetabulum using clinically identifiable regions. Subchondral acetabular bone density distribution maps were created bilaterally from 30 non-pathologic pelvic CT scans. The density maps were aligned orthogonal to the acetabular rim plane and divided into twelve zones. Average bone density was calculated in each of these zones and compared to investigate differences between regions within each acetabulum and between right and left sides in a given patient. In all patients, the zones corresponding to the dome and posterior wall of the acetabulum demonstrated significantly higher average bone densities than all other regions (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). Significant correlations (R=0.4 to 0.76, P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) were found between corresponding regions of the left and right sides in 10 of the 12 zones. The pattern of subchondral bone density distribution found in this study is consistent with previously observed bone density patterns in the acetabulum. Correspondence of right and left sides suggests that the distribution of loading on the acetabulum is similar on both sides in healthy individuals, though differences may exist in load sharing. Quantifying bone density patterns using zonal density map analysis may lead to a better understanding of the impact of traumatic injuries and progression of pathologic conditions in the hip joint.

Research paper thumbnail of Acetabular orientation variability and symmetry based on CT scans of adults

International Journal of Computer Assisted Radiology and Surgery, 2010

Purpose Understanding acetabular orientation is important in many orthopaedic procedures. Acetabu... more Purpose Understanding acetabular orientation is important in many orthopaedic procedures. Acetabular orientation, usually described by anteversion and abduction angles, has uncertain measurement variability in adult patients. The goals of this study are threefold: (1) to describe a new method for computing patient-specific abduction/anteversion angles from a single CT study based on the identification of anatomical landmarks and acetabular rim points; (2) to quantify the inaccuracies associated with landmark selection in computing the acetabular angles; and (3) to quantify the variability and symmetry of acetabular orientation. Methods A total of 25 CT studies from adult patients scanned for non-orthopaedic indications were retrospectively reviewed. The patients were randomly selected from the hospital's database. Inclusion criteria were adults 20-65 years of age. Acetabular landmark coordinates were identified by expert observers and tabulated in a spreadsheet. Two sets of calculations were done using the data: (1) computation of the abduction and anteversion for each patient, and (2) evaluation of the variability of measurements in the same individual by the same surgeon. The results were tabulated and summary statistics computed. Results This retrospective study showed that acetabular abduction and anteversion angles averaged 54 • and 17 • , respectively, in adults. A clinically significant intra-patient variability of >20 • was found. We also found that the right and left side rim plane orientation were significantly correlated, but were not always symmetric. Conclusion A new method of computing patient-specific abduction and anteversion angles from a CT study of the anterior pelvic plane and the left and right acetabular rim planes was reliable and accurate. We found that the acetabular rim plane can be reliably and accurately computed from identified points on the rim. The novelty of this work is that angular measurements are performed between planes on a 3-D model rather than lines on 2-D projections, as was done in the past.