The purpose of this study was to determine the incidence, and the clinical and radiographic risk ... more The purpose of this study was to determine the incidence, and the clinical and radiographic risk factors for significant subsidence of a cementless, modular tapered revision femoral stem. Femoral stem subsidence of at least 10 mm or subsidence requiring revision was considered significant subsidence. Ninety-seven patients (99 hips) were included with minimum radiographic follow-up of one year (mean 34 months; range, 12-91 months). The mean stem subsidence was 4.5 mm (range, 0-44 mm). Fourteen out of 99 (14.1%) stems had significant subsidence and 6 (6.1%) stems required revision due to subsidence. Patient weight greater than 80 kg (P=0.04) and femoral stem press-fit distance of less than 2 cm (P<0.01) were both independent risk factors for significant stem subsidence.
We hypothesised that a modified ETO in patients undergoing revision total hip arthroplasty (THA) ... more We hypothesised that a modified ETO in patients undergoing revision total hip arthroplasty (THA) for treatment of Vancouver B2/B3 peri-prosthetic fractures would be associated with good clinical outcomes. A retrospective review was conducted of 34 patients (mean age 73 years). At mean follow-up of 57 months, the ETO had healed in all patients. Two patients had subsidence of the femoral stem at two and three years postoperatively requiring revision, and one patient had a dislocation 3 months after surgery. The mean Harris Hip Score at the time of the final follow-up was 76.9 (range, 46-95); 23/34 patients had an excellent result, 7/34 a good result, and 4/34 a poor result. We conclude that satisfactory outcomes can be obtained using this technique.
Distal femoral varus osteotomy (DFVO) of the knee may be indicated for young, active patients wit... more Distal femoral varus osteotomy (DFVO) of the knee may be indicated for young, active patients with unicompartmental arthritis and valgus deformity. We report on 40 DFVOs with a mean follow-up of 123 months. At the most recent follow-up, 24 knees had good or excellent results (60%), 3 had fair results (7.5%), and 3 had poor results (7.5%). Four in the
Massive bone defects are challenging problems in revision knee surgery. When defects are large an... more Massive bone defects are challenging problems in revision knee surgery. When defects are large and uncontained (without a cortical rim), structural allografts may be used to provide support for femoral and tibial components. This study reviewed 68 structural allografts at a mean of 5.4 years for clinical and radiographic outcomes. Indications for grafts included periprosthetic fracture in 19 knees, aseptic loosening in 29, infection in 11 and instability in 2. Seven knees had both femoral and tibial allografts. Multiple implant designs were used including 7 hinged prostheses. Thirteen knees (13/61) failed due to graft related complications including one graft nonunion, three aseptic loosenings, three periprosthetic fractures, four infections, and two for instability. The case of graft nonunion was successfully treated with revision fixation and autologous bone graft. There were three cases of graft resorption, two graded as severe and one as moderate. These results are satisfactory ...
The Journal of bone and joint surgery. American volume, Jan 2, 2014
Osteochondral defects of the knee in young, active patients represent a challenge to the orthopae... more Osteochondral defects of the knee in young, active patients represent a challenge to the orthopaedic surgeon. Our study examined long-term outcomes of the use of fresh allograft for posttraumatic osteochondral and osteochondritis dissecans defects in the distal aspect of the femur.METHODS: We reviewed the cases of sixty-three patients who underwent osteochondral allograft transplantation to the distal aspect of the femur between 1972 and 1995. Five patients who resided out of the country were lost to follow-up. Indications for the allograft procedure were an age of less than fifty years and a unipolar posttraumatic osteochondral or osteochondritis dissecans defect in the distal aspect of the femur that was larger than 3 cm in diameter and 1 cm in depth.RESULTS: Fifty-eight patients ages eleven to forty-eight years at the time of surgery (mean age, twenty-eight years) were followed for a mean of 21.8 years (range, fifteen to thirty-two years). Thirteen of the fifty-eight cases requir...
The Journal of Trauma: Injury, Infection, and Critical Care, 2009
Backboards are routinely used to protect the spine of trauma patients during transportation. Neve... more Backboards are routinely used to protect the spine of trauma patients during transportation. Nevertheless, little is known about the biomechanical properties of this type of immobilization. To evaluate the mechanical support of the thoracolumbosacral spine provided by a standard backboard in comparison with various rigid immobilization surfaces, by examining their respective surface contact area (SCA). SCAs comparisons of a standard aluminum backboard, a rigid military stretcher, an aluminum backboard covered by blanket, 3 and 5 cm thickness foam, and a cushioned stretcher were made using 12 volunteers. The evaluation was performed by a computer- mediated system that generated a diagram indicating pressure distribution and SCA score in each volunteer. These data were compared with a medical grade mattress, which served as the control group. The median backboard's SCA was 14.6 +/- 5.5 times smaller than the stretcher's SCA (range 4.6-28, average 15, p < 0.001). Its median SCA was essentially doubled by covering it by a standard military blanket and tripled when covered by 3 cm layer of foam. Using a 5-cm layer of foam increased the backboard's SCA by 11 times. Cushioning the stretcher beneath the lumbar spine and the hamstrings by folded blankets, significantly improved its median SCA (96 +/- 31.1, range 36-125, average 89.7). The backboard's SCA was significantly inferior to all the other surfaces. Although no dynamic evaluation was performed, these data imply that backboards need to be appropriately cushioned or alternate surfaces should be employed to improve the mechanical support during trauma patient transportation. Level of evidence, Level I.
Intraarticular injections of the hip have traditionally required sonographic or fluoroscopic guid... more Intraarticular injections of the hip have traditionally required sonographic or fluoroscopic guidance assistance. Previous studies report high failure rates with injections based solely on anatomic landmarks. To examine the accuracy of a lateral injection technique in osteoarthritic patients without using image assistance. This study was conducted in the operating room in 40 consecutive patients about to undergo total hip arthroplasty. Before sedation, each patient was positioned in a lateral decubitus position. Under sterile conditions, methylene blue dye was injected through an 18G spinal needle that was inserted 1 cm proximal to the midline of the greater trochanter, and directed toward the superolateral aspect of the femoral neck, according to preoperative hip x-rays. Accuracy was assessed intraoperatively by examining the joint and surrounding tissues for the presence of dye. Injections were successful in 6 of the first 10 (60%) patients and in 25 of the remaining 30 (83.3%) patients. Overall, injections were successful in 31 of 40 (77.5%) patients with disseminated dye solely in the intracapsular space. In all 9 unsuccessful injections, the dye was located distal to the joint, along with the more lateral aspect of the femoral neck. Accuracy of injections, to the hip joint, based on anatomic landmarks and preoperative x-rays is similar to those documented for knee injections in the literature. When unsuccessful, the injected material was not found close to neurovascular structures. This technique has an acceptable learning curve and can be used safely in a standard office setting.
The Journal of Bone and Joint Surgery (American), 2014
Both synovial chondromatosis and femoroacetabular impingement present with hip pain and may lead ... more Both synovial chondromatosis and femoroacetabular impingement present with hip pain and may lead to hip osteoarthritis. We present a small case series and describe the clinical presentation, investigation, and treatment of patients with synovial chondromatosis who also had cam-type femoroacetabular impingement involving the same hip. Five patients (four men and one woman with a mean age of thirty-four years [range, thirty to thirty-seven years]) with unilateral synovial chondromatosis of the hip presented with clinical and radiographic features of ipsilateral cam-type femoroacetabular impingement. The diagnosis of associated synovial chondromatosis was made on the basis of preoperative imaging in four of the cases. All patients were treated with surgical hip dislocation, excision of the synovial chondromatosis loose bodies, and reshaping of the femoral head-neck junction. These hips exhibited radiographic features that are not typically seen with idiopathic cam-type femoroacetabular impingement, including femoral head hypertrophy, lateralization of the femoral head, and haziness in the acetabular fossa. None of the hips showed signs of advanced osteoarthritis intraoperatively. The alpha angle improved from a mean of 72.4° preoperatively to 42.6° postoperatively. At a mean of twenty-two months of follow-up, the patients had a mean Harris hip score of 80.6, substantially improved from the preoperative value of 39. Hips with synovial chondromatosis may present with clinical and radiographic features resembling those of cam-type femoroacetabular impingement. As simultaneous treatment of both conditions is best accomplished with surgical hip dislocation rather than other, less-extensive surgical approaches, we recommend preoperative consideration of synovial chondromatosis in patients presenting with unilateral cam-type femoroacetabular impingement.
This study assessed failures of allograft prosthesis composites (APC) and revisions with a new AP... more This study assessed failures of allograft prosthesis composites (APC) and revisions with a new APC. Twenty-one patients with failed APC's after revision hip arthroplasty with severe proximal femoral bone loss underwent revision with a new APC. Causes of failure were aseptic loosening (18 patients), infection (3 patients). Of these 21 APC revisions, two patients failed (after 60, 156 months). The 5 and 10 year survival rates were 83.5% (95% CI, 79-100%, number at risk 12 and 6 accordingly). In addition, two patients had non-union at the host-allograft bone junction and were augmented with bone autograft and plate. These results suggest that failed APCs may be revised to a new APC with a predictable outcome.
The purpose of this study was to determine the incidence, and the clinical and radiographic risk ... more The purpose of this study was to determine the incidence, and the clinical and radiographic risk factors for significant subsidence of a cementless, modular tapered revision femoral stem. Femoral stem subsidence of at least 10 mm or subsidence requiring revision was considered significant subsidence. Ninety-seven patients (99 hips) were included with minimum radiographic follow-up of one year (mean 34 months; range, 12-91 months). The mean stem subsidence was 4.5 mm (range, 0-44 mm). Fourteen out of 99 (14.1%) stems had significant subsidence and 6 (6.1%) stems required revision due to subsidence. Patient weight greater than 80 kg (P=0.04) and femoral stem press-fit distance of less than 2 cm (P<0.01) were both independent risk factors for significant stem subsidence.
We hypothesised that a modified ETO in patients undergoing revision total hip arthroplasty (THA) ... more We hypothesised that a modified ETO in patients undergoing revision total hip arthroplasty (THA) for treatment of Vancouver B2/B3 peri-prosthetic fractures would be associated with good clinical outcomes. A retrospective review was conducted of 34 patients (mean age 73 years). At mean follow-up of 57 months, the ETO had healed in all patients. Two patients had subsidence of the femoral stem at two and three years postoperatively requiring revision, and one patient had a dislocation 3 months after surgery. The mean Harris Hip Score at the time of the final follow-up was 76.9 (range, 46-95); 23/34 patients had an excellent result, 7/34 a good result, and 4/34 a poor result. We conclude that satisfactory outcomes can be obtained using this technique.
Distal femoral varus osteotomy (DFVO) of the knee may be indicated for young, active patients wit... more Distal femoral varus osteotomy (DFVO) of the knee may be indicated for young, active patients with unicompartmental arthritis and valgus deformity. We report on 40 DFVOs with a mean follow-up of 123 months. At the most recent follow-up, 24 knees had good or excellent results (60%), 3 had fair results (7.5%), and 3 had poor results (7.5%). Four in the
Massive bone defects are challenging problems in revision knee surgery. When defects are large an... more Massive bone defects are challenging problems in revision knee surgery. When defects are large and uncontained (without a cortical rim), structural allografts may be used to provide support for femoral and tibial components. This study reviewed 68 structural allografts at a mean of 5.4 years for clinical and radiographic outcomes. Indications for grafts included periprosthetic fracture in 19 knees, aseptic loosening in 29, infection in 11 and instability in 2. Seven knees had both femoral and tibial allografts. Multiple implant designs were used including 7 hinged prostheses. Thirteen knees (13/61) failed due to graft related complications including one graft nonunion, three aseptic loosenings, three periprosthetic fractures, four infections, and two for instability. The case of graft nonunion was successfully treated with revision fixation and autologous bone graft. There were three cases of graft resorption, two graded as severe and one as moderate. These results are satisfactory ...
The Journal of bone and joint surgery. American volume, Jan 2, 2014
Osteochondral defects of the knee in young, active patients represent a challenge to the orthopae... more Osteochondral defects of the knee in young, active patients represent a challenge to the orthopaedic surgeon. Our study examined long-term outcomes of the use of fresh allograft for posttraumatic osteochondral and osteochondritis dissecans defects in the distal aspect of the femur.METHODS: We reviewed the cases of sixty-three patients who underwent osteochondral allograft transplantation to the distal aspect of the femur between 1972 and 1995. Five patients who resided out of the country were lost to follow-up. Indications for the allograft procedure were an age of less than fifty years and a unipolar posttraumatic osteochondral or osteochondritis dissecans defect in the distal aspect of the femur that was larger than 3 cm in diameter and 1 cm in depth.RESULTS: Fifty-eight patients ages eleven to forty-eight years at the time of surgery (mean age, twenty-eight years) were followed for a mean of 21.8 years (range, fifteen to thirty-two years). Thirteen of the fifty-eight cases requir...
The Journal of Trauma: Injury, Infection, and Critical Care, 2009
Backboards are routinely used to protect the spine of trauma patients during transportation. Neve... more Backboards are routinely used to protect the spine of trauma patients during transportation. Nevertheless, little is known about the biomechanical properties of this type of immobilization. To evaluate the mechanical support of the thoracolumbosacral spine provided by a standard backboard in comparison with various rigid immobilization surfaces, by examining their respective surface contact area (SCA). SCAs comparisons of a standard aluminum backboard, a rigid military stretcher, an aluminum backboard covered by blanket, 3 and 5 cm thickness foam, and a cushioned stretcher were made using 12 volunteers. The evaluation was performed by a computer- mediated system that generated a diagram indicating pressure distribution and SCA score in each volunteer. These data were compared with a medical grade mattress, which served as the control group. The median backboard's SCA was 14.6 +/- 5.5 times smaller than the stretcher's SCA (range 4.6-28, average 15, p < 0.001). Its median SCA was essentially doubled by covering it by a standard military blanket and tripled when covered by 3 cm layer of foam. Using a 5-cm layer of foam increased the backboard's SCA by 11 times. Cushioning the stretcher beneath the lumbar spine and the hamstrings by folded blankets, significantly improved its median SCA (96 +/- 31.1, range 36-125, average 89.7). The backboard's SCA was significantly inferior to all the other surfaces. Although no dynamic evaluation was performed, these data imply that backboards need to be appropriately cushioned or alternate surfaces should be employed to improve the mechanical support during trauma patient transportation. Level of evidence, Level I.
Intraarticular injections of the hip have traditionally required sonographic or fluoroscopic guid... more Intraarticular injections of the hip have traditionally required sonographic or fluoroscopic guidance assistance. Previous studies report high failure rates with injections based solely on anatomic landmarks. To examine the accuracy of a lateral injection technique in osteoarthritic patients without using image assistance. This study was conducted in the operating room in 40 consecutive patients about to undergo total hip arthroplasty. Before sedation, each patient was positioned in a lateral decubitus position. Under sterile conditions, methylene blue dye was injected through an 18G spinal needle that was inserted 1 cm proximal to the midline of the greater trochanter, and directed toward the superolateral aspect of the femoral neck, according to preoperative hip x-rays. Accuracy was assessed intraoperatively by examining the joint and surrounding tissues for the presence of dye. Injections were successful in 6 of the first 10 (60%) patients and in 25 of the remaining 30 (83.3%) patients. Overall, injections were successful in 31 of 40 (77.5%) patients with disseminated dye solely in the intracapsular space. In all 9 unsuccessful injections, the dye was located distal to the joint, along with the more lateral aspect of the femoral neck. Accuracy of injections, to the hip joint, based on anatomic landmarks and preoperative x-rays is similar to those documented for knee injections in the literature. When unsuccessful, the injected material was not found close to neurovascular structures. This technique has an acceptable learning curve and can be used safely in a standard office setting.
The Journal of Bone and Joint Surgery (American), 2014
Both synovial chondromatosis and femoroacetabular impingement present with hip pain and may lead ... more Both synovial chondromatosis and femoroacetabular impingement present with hip pain and may lead to hip osteoarthritis. We present a small case series and describe the clinical presentation, investigation, and treatment of patients with synovial chondromatosis who also had cam-type femoroacetabular impingement involving the same hip. Five patients (four men and one woman with a mean age of thirty-four years [range, thirty to thirty-seven years]) with unilateral synovial chondromatosis of the hip presented with clinical and radiographic features of ipsilateral cam-type femoroacetabular impingement. The diagnosis of associated synovial chondromatosis was made on the basis of preoperative imaging in four of the cases. All patients were treated with surgical hip dislocation, excision of the synovial chondromatosis loose bodies, and reshaping of the femoral head-neck junction. These hips exhibited radiographic features that are not typically seen with idiopathic cam-type femoroacetabular impingement, including femoral head hypertrophy, lateralization of the femoral head, and haziness in the acetabular fossa. None of the hips showed signs of advanced osteoarthritis intraoperatively. The alpha angle improved from a mean of 72.4° preoperatively to 42.6° postoperatively. At a mean of twenty-two months of follow-up, the patients had a mean Harris hip score of 80.6, substantially improved from the preoperative value of 39. Hips with synovial chondromatosis may present with clinical and radiographic features resembling those of cam-type femoroacetabular impingement. As simultaneous treatment of both conditions is best accomplished with surgical hip dislocation rather than other, less-extensive surgical approaches, we recommend preoperative consideration of synovial chondromatosis in patients presenting with unilateral cam-type femoroacetabular impingement.
This study assessed failures of allograft prosthesis composites (APC) and revisions with a new AP... more This study assessed failures of allograft prosthesis composites (APC) and revisions with a new APC. Twenty-one patients with failed APC's after revision hip arthroplasty with severe proximal femoral bone loss underwent revision with a new APC. Causes of failure were aseptic loosening (18 patients), infection (3 patients). Of these 21 APC revisions, two patients failed (after 60, 156 months). The 5 and 10 year survival rates were 83.5% (95% CI, 79-100%, number at risk 12 and 6 accordingly). In addition, two patients had non-union at the host-allograft bone junction and were augmented with bone autograft and plate. These results suggest that failed APCs may be revised to a new APC with a predictable outcome.
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Papers by Oleg Safir