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Myung Chul Yoo - One of the best experts on this subject based on the ideXlab platform.

  • Radiological Changes After Metal on Metal Resurfacing Arthroplasty
    Journal of Bone and Joint Surgery-british Volume, 2013
    Co-Authors: Yoon Je Cho, Young Soo Chun, Kee Hyung Rhyu, Joo-hyun Lee, Sangjoon Kwak, Ye Yeon Won, Myung Chul Yoo
    Abstract:

    Purpose To evaluate the radiological changes after metal on metal Resurfacing Arthroplasty. Materials and Methods Between December 1998 and August 2004, 166 hips in 150 patients who underwent metal Resurfacing Arthroplasty and followed up more than 4 years. Their mean age at the time of operation was 37.3 years(range, 15–68 years) and mean period of follow-up was 6.1 years(range, 48–95 months). The cause of Arthroplasty included 115 avascular necrosis, 43 osteoarthritis, 7 ankylosing spondylitis, 1 haemophilic arthropathy. All patients had anteroposterior, translateral radiographs of the hip made preoperatively and each follow-up visit, and we analyzed radiographic findings such as radiolucencies or impingement signs around implant, neck narrowing and heterotopic ossification. Results There was a no significant difference between preoperative and postoperative Harris hip score and range of motion. The mean stem-shaft angle was 137.4°, and 55.4% were ranged 130° to 140°. The mean inclination of acetabular component was 44.9°. There were no radiolucent lines or osteolytic lesion around the acetabular components, but 3 hips showed radiolucency around the head-neck junction(1.8%) and 4 hips showed radiolucent line around the stem (2.4%). 12 hips had impingement signs around the head-neck junction (7.2%), and 2 cases showed neck narrowing (1.2%). 3 cases had some heterotopic ossification (1.8%). In 12 cases with impingement signs, the stem-shaft angle and inclination of acetabular component were lower than control group. Pseudotumor was not found in this cohort. Conclusions This study demonstrates no serious radiological problems till the midterm follow-up after Resurfacing Arthroplasty, but osteolytic lesion such as radiolucent line around head-neck junction, neck narrowing can be a potential cause of failure in future. Even though the radiolucent line around stem of femoral component revealed no subjective symptom yet, it suggests the micromotion of femoral component which can lead to femoral component loosening. The most common radiological findings, impingement signs, seem not to have clinical significance.

  • Impingement between the acetabular cup and the femoral neck after hip Resurfacing Arthroplasty.
    Journal of Bone and Joint Surgery, 2011
    Co-Authors: Myung Chul Yoo, Yoon Je Cho, Young Soo Chun, Kee Hyung Rhyu
    Abstract:

    Background: Loosening, femoral neck fracture, and metal ion release have been well documented after hip Resurfacing Arthroplasty, but impingement between the acetabular cup and the femoral neck has not. The goal of this study was to analyze radiographic findings that were presumed to represent impingement of the neck after hip Resurfacing Arthroplasty, and to describe the mechanism of impingement. Methods: Of the 635 hips (579 patients) that underwent hip Resurfacing Arthroplasty between September 1998 and May 2008, forty hips (6.3%) with positive radiographic findings were available for this study. The mean age of the patients was 34.9 years and there were thirty-five men and five women. The average follow-up was sixty-eight months (twenty-four to 132 months). Radiographic evaluation included an analysis of neck-shaft angle, inclination of the acetabular cup, head-neck ratio, lateral protrusion of the cup, anterior protrusion of the cup, and stem angle to the axis of the femoral neck. Results: Impingement between the acetabular cup and the femoral neck occurred in 6.3% of hips and appeared at an average of seven months after surgery. There was no further change two years postoperatively. The impingement findings did not correlate with the clinical outcome, but all instances of impingement were located in the lateral or anterolateral part of the femoral neck along the arc from the center of the femoral head to the lateral edge of the socket. No significant factors were found to be related to the occurrence of impingement. Conclusions: Femoral-neck impingement should be differentiated from notching, narrowing, stress-shielding, or osteolysis of the femoral neck. Although we found no significant factors to explain the impingement found in the hips in our study, it appears that repetitive extreme motion of the involved hip and malposition of the implants can cause impingement after hip Resurfacing Arthroplasty. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

  • Hip Resurfacing Arthroplasty in Patients with Rheumatoid Arthritis
    Journal of Rheumatic Diseases, 2011
    Co-Authors: Yoon Je Cho, Young Soo Chun, Kang-il Kim, Kee Hyung Rhyu, Myung Chul Yoo, Hyuk Hong
    Abstract:

    Objective. This study analyzed the midterm results of hip Resurfacing Arthroplasty in patients with rheumatoid arthritis. Methods. Between October of 2003 and September of 2008, 13 consecutive hips that were treated with hip Resurfacing Arthroplasty due to rheumatoid arthritis were analyzed. The average follow up period was 48.6 months and the mean age at the time of operation was 35.9 years old. The mean BMI at the operation was 23.2 kg/m 2 . The implanted prostheses were the Conserve Plus system in five hips, the Birmingham hip Resurfacing system in four hips and the Durom system in four hips. The results were clinically evaluated with the Harris hip score, the UCLA activity score, hip or thigh pain, the limb length discrepancy and the range of motion. As radiological evaluation, we observed the patterns of bone remodeling and complications such as femoral neck fracture, loosening and osteolysis. Results. The average Harris hip score improved from 62.2 to 98.9 at the final visit. The range of motion improved to 0 o in flexion contracture, 118.1 o in further flexion, 22.7 o

  • Impingement between the acetabular cup and the femoral neck after hip Resurfacing Arthroplasty.
    The Journal of bone and joint surgery. American volume, 2011
    Co-Authors: Myung Chul Yoo, Yoon Je Cho, Young Soo Chun, Kee Hyung Rhyu
    Abstract:

    Loosening, femoral neck fracture, and metal ion release have been well documented after hip Resurfacing Arthroplasty, but impingement between the acetabular cup and the femoral neck has not. The goal of this study was to analyze radiographic findings that were presumed to represent impingement of the neck after hip Resurfacing Arthroplasty, and to describe the mechanism of impingement. Of the 635 hips (579 patients) that underwent hip Resurfacing Arthroplasty between September 1998 and May 2008, forty hips (6.3%) with positive radiographic findings were available for this study. The mean age of the patients was 34.9 years and there were thirty-five men and five women. The average follow-up was sixty-eight months (twenty-four to 132 months). Radiographic evaluation included an analysis of neck-shaft angle, inclination of the acetabular cup, head-neck ratio, lateral protrusion of the cup, anterior protrusion of the cup, and stem angle to the axis of the femoral neck. Impingement between the acetabular cup and the femoral neck occurred in 6.3% of hips and appeared at an average of seven months after surgery. There was no further change two years postoperatively. The impingement findings did not correlate with the clinical outcome, but all instances of impingement were located in the lateral or anterolateral part of the femoral neck along the arc from the center of the femoral head to the lateral edge of the socket. No significant factors were found to be related to the occurrence of impingement. Femoral-neck impingement should be differentiated from notching, narrowing, stress-shielding, or osteolysis of the femoral neck. Although we found no significant factors to explain the impingement found in the hips in our study, it appears that repetitive extreme motion of the involved hip and malposition of the implants can cause impingement after hip Resurfacing Arthroplasty.

  • RESULTS OF HIP Resurfacing Arthroplasty (HRA) IN PATIENTS WITH OSTEONECROSIS OF THE FEMORAL HEAD
    2010
    Co-Authors: Myung Chul Yoo
    Abstract:

    Although total hip Arthroplasty (THA) is quite predictable and durable in older patients, young and active patients have higher rates of revision and these rates are especially increased when the etiology is osteonecrosis. Recent advancement of hip Resurfacing technology, HRA has been revived again. Numerous advantages and promising results of HRA have been published. But patient selection and techniques etc still remain issues for HRA in general and especially for patients with osteonecrosis. In the case of HRA in patients with osteoarthritis, the bone quality is stronger and there is no head necrosis and surgical techniques are fundamentally different when compared to osteonecrosis. In osteonecrosis, there is a higher risk and greater concern of the neck fracture due to necrosis and osteoporosis, insecure fixations as well as a progression of necrosis in the subchondral bone. These factors should be considered when assessing hips with osteonecrosis. The ultimate assessment is the condition of the prepared femoral head. This makes Resurfacing Arthroplasty for osteonecrosis a challenging procedure. This study was performed to assess the overall clinical and radiological results of the total Resurfacing Arthroplasty for the patients with osteonecrosis of the femoral head(ONFH) after a minimum 5 year-follow-up. 444 hips of ONFH received Resurfacing Arthroplasty from Sep 1998 to Mar.2008. 88 hips which were followed up minimally 5 years were included in this study. Among 88 hips(79 patients) of ONFH that have underwent hip Resurfacing arthroplasties from Dec 1998 to Apr 2003, 85 hips(76 patients) were available for the complete study. The mean age at the time of operation was 37 (16–67) years old. The average follow-up period was 80 (60–112) months. The patients were clinically evaluated with the Harris hip score, hip or thigh pain, limb length discrepancy and range of motion. As a radiological evaluation, we observed the changes of implant position, patterns of bone remodeling in the neck and complications such as femoral neck fracture, loosening and osteolysis. Metal ion in the serum was also analysed. The Harris hip score increased from 77.8 preoperatively to 98.4 at the final visit. Hip abduction/adduction and rotations significantly improved after the operation. Flexion contracture disappeared and further flexion also returned to almost normal. No patient complained of limb length discrepancy and pain on the hip or thigh at the last visit. Although they are not related to the clinical result, some cases showed various types of radiographic changes in the neck of the proximal femur. Neck narrowing was observed in 3 hips. There was no detectable wear or change of position of the acetabular cup and femoral stem. Our experience with Resurfacing Arthroplasty in osteonecrosis of the femoral head indicates that the overall results are superior to conventional THA in the aspect of pain relief, the range of hip motion, earlier rehabilitation and earlier return to preoperative activity. This procedure of his Resurfacing Arthroplasty could be an alternative between joint preserving procedures and THA in the case of early-to-mid staged osteonecrosis of the femoral head especially in younger patients who need Arthroplasty. Extent and location of necrosis, and bone quality are the most important factors in Resurfacing Arthroplasty in osteonecrosis. Precise preoperative planning and meticulous surgical technique is needed to perform Resurfacing Arthroplasty. But long-term studies are needed to determine the survivorship and to evaluate the metal toxicity after Resurfacing Arthroplasty.

Michael Amling - One of the best experts on this subject based on the ideXlab platform.

  • association of osteonecrosis and failure of hip Resurfacing Arthroplasty
    Clinical Orthopaedics and Related Research, 2010
    Co-Authors: Jozef Zustin, Michael M. Morlock, Wolfgang Rüther, Guido Sauter, Michael Amling
    Abstract:

    Osteonecrosis (ON) has been reported in femoral remnants removed after failure of hip Resurfacing Arthroplasty. Experimental and clinical studies have further described thermal effects of the cementation technique, damage of extraosseous blood vessels, and intraoperative hypoxemia as possible causative factors. We analyzed histologically a series of 123 retrieved specimens with a preoperative diagnosis other than ON to investigate the incidence and extent of advanced ON. ON was found in 88% of cases and associated with 60% (51 of a total of 85) of periprosthetic fractures. The fracture incidence correlated with the extent of ON. Collapse of necrotic tissue in three (2%) cases resulted in disconnection of the bone stock-femoral component. We observed smaller regions of superficial ON in the majority of the remaining femoral remnants with periprosthetic fractures and in hips that failed for reasons other than fracture.

  • morphologic analysis of periprosthetic fractures after hip Resurfacing Arthroplasty
    Journal of Bone and Joint Surgery American Volume, 2010
    Co-Authors: Jozef Zustin, Michael Hahn, Michael M. Morlock, Wolfgang Rüther, Guido Sauter, Matthias Krause, Stefan Breer, Christoph Von Domarus, Michael Amling
    Abstract:

    Background: Periprosthetic fractures have long been recognized as one of the major complications of hip Resurfacing Arthroplasty. The objective of this study was to develop a systematic and morphologic classification of the fracture mode based on pathogenesis. Methods: One hundred and seven retrieved specimens consisting of the femoral remnant and the femoral component of a total hip Resurfacing Arthroplasty that had failed as a result of a periprosthetic fracture were analyzed with regard to the morphologic failure mode. The location of the fracture line was used to differentiate the fractures. The fractures were also classified histopathologically as acute biomechanical, acute postnecrotic, or chronic biomechanical. Results: Fifty-nine percent (sixty-three) of the fractures occurred within the bone inside the femoral component. Fifty-one percent (fifty-five) of the fractures were classified morphologically as acute postnecrotic; 40% (forty-three), as chronic biomechanical; and 8% (nine), as acute biomechanical. Acute biomechanical fractures were found exclusively in the femoral neck and occurred earlier (mean time [and standard deviation] between implantation and revision, 41 ± 57 days) than acute postnecrotic fractures (mean time between implantation and revision, 149 ± 168 days; p = 0.002) or chronic biomechanical fractures (mean time between implantation and revision, 179 ± 165 days; p = 0.001). The latter two fracture types both occurred predominantly in the bone inside the femoral component. Conclusions: Three distinct fracture modes were characterized morphologically. Osteonecrosis was the most frequent cause of fracture-related failures. We suggest that an intraoperative mechanical injury of the femoral neck such as notching and/or malpositioning of the femoral component might lead to changes in the loading pattern or in the resistance to fracture of the femoral neck and may result in both acute and chronic biomechanical femoral neck fractures. These findings may serve as feedback information for the surgeon and possibly influence future therapeutic strategies.

  • Femoral component loosening after hip Resurfacing Arthroplasty
    Skeletal radiology, 2010
    Co-Authors: Jozef Zustin, Michael Hahn, Michael M. Morlock, Wolfgang Rüther, Michael Amling, Guido Sauter
    Abstract:

    Objective Before the re-introduction of the current generation of total hip Resurfacing Arthroplasty, component loosening and osteolysis were of great concern to the orthopaedic community. Early, mid- and long-term clinical results are encouraging, but component loosening still exists.

  • Reply to Letter to the Editor: Association of Osteonecrosis and Failure of Hip Resurfacing Arthroplasty
    Clinical Orthopaedics & Related Research, 2010
    Co-Authors: Jozef Zustin, Michael Amling
    Abstract:

    We thank Doctors Kannan and Malhotra for their letter regarding our manuscript, Association of Osteonecrosis and Failure of Hip Resurfacing Arthroplasty [12]. They have challenged the evidence we presented suggesting osteonecrosis (ON) was associated with substantial failures of hip Resurfacing Arthroplasty [12]. More specifically, they questioned if (1) ON could not occur secondary to a periprosthetic fracture, (2) we analyzed the central section from the femoral remnant according to Howie et al. [5] to confirm the occurrence of superficial and generalized ON, and (3) patients with posttraumatic arthritis did not have ON develop before the Resurfacing procedure. We explained thoroughly the criteria for diagnosis of ON lesions in our study. We defined advanced ON lesions microscopically as the presence of trabeculae without stainable osteocytes, disorganized bone marrow, and bordering fibrosis, and by contact radiography of the specimens because of the observation of bordering sclerosis. Qui et al. [9] showed that remnants of apoptotic osteocytes may remain in situ for several weeks or months, recognizable by pyknotic nuclei using conventional light microscopy, but eventually the remnants become undetectable, leaving an apparently empty lacuna. This morphologic finding is considered a reliable sign that the osteocyte originally present has died [9]. Similarly, ON becomes recognizable radiographically the first several weeks or months after the fracture [6, 11]. Our definition of an advanced ON lesion also included the absence of an interface histiocyte reaction to cement as described by Bogoch et al. [1]. Therefore, we suggested ON probably was a cause of the specific type of periprosthetic fractures after a hip Resurfacing Arthroplasty (51 hips of a total of 85 failures associated with fracture) which occurred acutely in all cases with valid clinical data. Kannan and Malhotra correctly pointed out that previous retrieval analyses have shown varying rates of evidence of ON. Little et al. [7] and Steffen et al. [10] reported even greater occurrences of ON in hips revised for periprosthetic fractures after a Resurfacing Arthroplasty, however, the total number of retrieved hips was smaller. They suggested ON played a major role in periprosthetic fracture after the current generation hip Resurfacing Arthroplasty. In the study by Campbell et al. [3], the majority (70 of 98 hips) of revisions in their cohort were not attributable to fractures, and they detected ON in all five hips with an in situ time longer than 6 months, however, they did not discuss in detail the occurrence of ON in fractures that occurred within a short time. Based on our observations, we proposed that ON led to failure of the Resurfacing Arthroplasty predominantly within the first few months after implantation. Postnecrotic fractures in our study cohort were revised with a mean in situ time of 5.3 months. Although Forrest et al. [4] and McMahon et al. [8] radiographically analyzed well-functioning hips after a followup longer than 18 months and their cases were not analyzed morphologically, the comparison with our retrieval study does not seem to be reasonable. Furthermore, we also consider the comparison with the second-generation hip Resurfacing Arthroplasty not quite appropriate. There are several substantial differences in design and clinical outcome of the second as compared with the current generation hip Resurfacing Arthroplasty. Howie et al. [5] analyzed 72 cases mainly with intermediate- and long-term failures (none was revised within the first 6 months after implantation) and focused primarily on a possible association of ON with loosening. Bradley et al. [2] found two of 25 resurfaced hips revised for fracture had substantial regions of ON, and Bogoch et al. [1] found ON of the entire femoral head in three of four fractures. Therefore, our observations are consistent with those in the literature. Owing to design of the femoral component in the current generation hip Resurfacing Arthroplasty, it is impossible to analyze sections from the central areas as did Howie et al. [5]: the current generation femoral components are stemmed and the tissue from the central part of the femoral remnant is removed at implantation surgery. Nonetheless, we analyzed the tissue present between the superficial and central areas of the femoral remnant. By examining sections from three quadrants of each femoral remnant in their full length with a standardized sampling procedure, we believe we adequately addressed the question of sampling: the extent of ON was determined from the entire remnant rather than only the superficial and control portions. All ON lesions we observed were connected with the proximal surface of the bone remnant. We are not aware of any report of an isolated ON lesion after a hip Resurfacing Arthroplasty in the central or distal part of the femoral remnant without including its proximal areas. In addition, to avoid any possible misdiagnosis in cases with primary avascular necrosis of the femoral head, we excluded hips with this preoperative diagnosis. Drs Kannan and Malhotra correctly pointed out that in cases with posttraumatic arthritis, morphologic changes related to the initial traumatic event or its subsequent therapy might have led to ON before implantation. Preoperative biopsy information from hips before implantation was not available and could have been available only from the removed central region where the stem was located. As we examined only seven hips with a preoperative diagnosis of posttraumatic arthritis, this specific issue remained unanswered by our study. However, we found ON lesions in each hip from this group. Moreover, three of the six hips with posttraumatic arthritis with failed results attributable to periprosthetic fractures after the Resurfacing Arthroplasty were considered as having postnecrotic fractures. Because we did not have a control group (eg, examining for ON in patients without implant failure and/or femoral heads removed for conventional total hip Arthroplasty), any statements regarding possible relationships would be highly speculative. This question, however, might be adequately answered by clinical and radiographic studies. Based on our observations, we believe it is reasonable to presume the presence and the extent of ON after a Resurfacing Arthroplasty may be linked to complications from the Arthroplasty. Again we thank Drs Kannan and Malhotra for their insightful comments.

  • Intraosseous lymphocytic infiltrates after hip Resurfacing Arthroplasty
    Virchows Archiv, 2009
    Co-Authors: Jozef Zustin, Michael Hahn, Michael M. Morlock, Wolfgang Rüther, Michael Amling, Matthias Krause, Stefan Breer, Guido Sauter
    Abstract:

    To identify a possible role of lymphocytic infiltrates in failure mechanism of the metal-on-metal hip Resurfacing Arthroplasty, the extent of lymphocytic infiltration was compared with reasons for prosthesis failure in a series of retrieval specimens. One hundred eighty-one femoral head and neck remnants were subjected to thorough analysis of histological findings and clinical data. Lymphocytic infiltrates were considered weak to moderate in 52 (28.7%) and excessive in ten (5.5%) cases. Six cases with excessive lymphocytic infiltrates belonged to the group of 33 (18.2%) revisions without obvious cause (periprosthetic fracture, component loosening, and infection) for prosthesis failure. Excessive lymphocytic infiltrates were strongly linked to the presence of proliferative desquamative synovitis ( p  

Matthew L. Costa - One of the best experts on this subject based on the ideXlab platform.

  • Cost-effectiveness of total hip Arthroplasty versus Resurfacing Arthroplasty: economic evaluation alongside a clinical trial.
    BMJ open, 2012
    Co-Authors: Richard Edlin, Sandy Tubeuf, Juul Achten, Nicholas R. Parsons, Matthew L. Costa
    Abstract:

    Objective: To report on the relative cost-effectiveness of total hip Arthroplasty and Resurfacing Arthroplasty (replacement of articular surface of femoral head only) in patients with severe arthritis suitable for hip joint Resurfacing Arthroplasty. Design: Cost-effectiveness analysis on an intention-to-treat basis of a single-centre, single-blind randomised controlled trial of 126 adult patients within 12 months of treatment. Missing data were imputed using multiple imputations with differences in baseline quality of life and gender adjusted using regression techniques. Setting: A large teaching hospital trust in the UK. Participants: A total of 126 adult patients with severe arthritis of the hip joint suitable for a Resurfacing Arthroplasty of the hip. Results: Data were received for 126 patients, 4 of whom did not provide any resource use data. For the remainder, data were imputed for costs or quality of life in at least one time point (baseline, 3, 6 months and 1 year) for 18 patients. Patients in the Resurfacing arm had higher quality of life at 12 months (0.795 vs 0.727) and received 0.032 more QALYs within the first 12 months postoperation. At an additional cost of £564, Resurfacing Arthroplasty offers benefits at £17 451 per QALY within the first 12 months of treatment. When covariates are considered, the health economic case is stronger in men than in women. Conclusions: Resurfacing Arthroplasty appears to offer very short-term efficiency benefits over total hip Arthroplasty within a selected patient group. The short-term follow-up in this trial should be noted, particularly in light of the concerns raised regarding adverse reactions to metal debris from metal-on-metal bearing surfaces in the longer term. Longer-term follow-up of Resurfacing Arthroplasty patients and decision analytic modelling is also advised. Trial registration Current controlled Trials: ISRCTN33354155. UKCRN 4093.

  • Cost-effectiveness of total hip Arthroplasty versus Resurfacing Arthroplasty in the treatment of young people : economic evaluation alongside a clinical trial
    2012
    Co-Authors: Richard Edlin, Sandy Tubeuf, Juul Achten, Nicholas R. Parsons, Matthew L. Costa
    Abstract:

    Objectives: To report on the relative cost-effectiveness of total hip Arthroplasty and Resurfacing Arthroplasty (replacement of articular surface of femoral head only) in patients with severe arthritis suitable for hip joint Resurfacing Arthroplasty. Design: Cost-effectiveness analysis (cost per QALY) on an intention to treat basis of a singlecentre, single-blind randomised controlled trial of 126 adult patients within 12 months of treatment. Missing data was assessed using multiple imputations with differences in baseline quality of life and gender adjusted using regression techniques. Setting: A large teaching hospital trust in the UK Participants: 126 adult patients with severe arthritis of the hip joint suitable for a Resurfacing Arthroplasty of the hip. Results: Data was received for 126 patients, 4 of whom did not provide any resource use data. For the remainder, data was imputed for costs or quality of life in at least one time point (baseline, 3 months, 6 months, 1 year) for 18 patients. Patients in the Resurfacing arm had higher quality of life at 12 months (0.795 vs. 0.727) and received 0.033 more QALYs within the first 12 months post operation. At an additional cost of £410, Resurfacing Arthroplasty offers benefits at £12,374 per QALY within the first 12 months of treatment. When covariates are considered, the health economic case is stronger in men than women. Conclusions: Resurfacing Arthroplasty appears to offer very short term efficiency benefits over total hip Arthroplasty within a selected patient group. This conclusion should be tested over a longer period through longer series following up Resurfacing Arthroplasty and through decision analytic modelling.

  • the blood flow to the femoral head neck junction during Resurfacing Arthroplasty a comparison of two approaches using laser doppler flowmetry
    Journal of Bone and Joint Surgery-british Volume, 2008
    Co-Authors: H. W. Amarasekera, Matthew L. Costa, P. Foguet, S. J. Krikler, U. Prakash, D. R. Griffin
    Abstract:

    We used Laser Doppler flowmetry to measure the effect on the blood flow to the femoral head/neck junction of two surgical approaches during Resurfacing Arthroplasty. We studied 24 hips undergoing Resurfacing Arthroplasty for osteoarthritis. Of these, 12 had a posterior approach and 12 a trochanteric flip approach. A Laser probe was placed under radiological control in the superolateral part of the femoral head/neck junction. The Doppler flux was measured at stages of the operation and compared with the initial flux. In both groups the main fall in blood flow occurred during the initial exposure and capsulotomy of the hip joint. There was a greater reduction in blood flow with the posterior (40%) than with the trochanteric flip approach (11%).

Jozef Zustin - One of the best experts on this subject based on the ideXlab platform.

  • association of osteonecrosis and failure of hip Resurfacing Arthroplasty
    Clinical Orthopaedics and Related Research, 2010
    Co-Authors: Jozef Zustin, Michael M. Morlock, Wolfgang Rüther, Guido Sauter, Michael Amling
    Abstract:

    Osteonecrosis (ON) has been reported in femoral remnants removed after failure of hip Resurfacing Arthroplasty. Experimental and clinical studies have further described thermal effects of the cementation technique, damage of extraosseous blood vessels, and intraoperative hypoxemia as possible causative factors. We analyzed histologically a series of 123 retrieved specimens with a preoperative diagnosis other than ON to investigate the incidence and extent of advanced ON. ON was found in 88% of cases and associated with 60% (51 of a total of 85) of periprosthetic fractures. The fracture incidence correlated with the extent of ON. Collapse of necrotic tissue in three (2%) cases resulted in disconnection of the bone stock-femoral component. We observed smaller regions of superficial ON in the majority of the remaining femoral remnants with periprosthetic fractures and in hips that failed for reasons other than fracture.

  • morphologic analysis of periprosthetic fractures after hip Resurfacing Arthroplasty
    Journal of Bone and Joint Surgery American Volume, 2010
    Co-Authors: Jozef Zustin, Michael Hahn, Michael M. Morlock, Wolfgang Rüther, Guido Sauter, Matthias Krause, Stefan Breer, Christoph Von Domarus, Michael Amling
    Abstract:

    Background: Periprosthetic fractures have long been recognized as one of the major complications of hip Resurfacing Arthroplasty. The objective of this study was to develop a systematic and morphologic classification of the fracture mode based on pathogenesis. Methods: One hundred and seven retrieved specimens consisting of the femoral remnant and the femoral component of a total hip Resurfacing Arthroplasty that had failed as a result of a periprosthetic fracture were analyzed with regard to the morphologic failure mode. The location of the fracture line was used to differentiate the fractures. The fractures were also classified histopathologically as acute biomechanical, acute postnecrotic, or chronic biomechanical. Results: Fifty-nine percent (sixty-three) of the fractures occurred within the bone inside the femoral component. Fifty-one percent (fifty-five) of the fractures were classified morphologically as acute postnecrotic; 40% (forty-three), as chronic biomechanical; and 8% (nine), as acute biomechanical. Acute biomechanical fractures were found exclusively in the femoral neck and occurred earlier (mean time [and standard deviation] between implantation and revision, 41 ± 57 days) than acute postnecrotic fractures (mean time between implantation and revision, 149 ± 168 days; p = 0.002) or chronic biomechanical fractures (mean time between implantation and revision, 179 ± 165 days; p = 0.001). The latter two fracture types both occurred predominantly in the bone inside the femoral component. Conclusions: Three distinct fracture modes were characterized morphologically. Osteonecrosis was the most frequent cause of fracture-related failures. We suggest that an intraoperative mechanical injury of the femoral neck such as notching and/or malpositioning of the femoral component might lead to changes in the loading pattern or in the resistance to fracture of the femoral neck and may result in both acute and chronic biomechanical femoral neck fractures. These findings may serve as feedback information for the surgeon and possibly influence future therapeutic strategies.

  • Femoral component loosening after hip Resurfacing Arthroplasty
    Skeletal radiology, 2010
    Co-Authors: Jozef Zustin, Michael Hahn, Michael M. Morlock, Wolfgang Rüther, Michael Amling, Guido Sauter
    Abstract:

    Objective Before the re-introduction of the current generation of total hip Resurfacing Arthroplasty, component loosening and osteolysis were of great concern to the orthopaedic community. Early, mid- and long-term clinical results are encouraging, but component loosening still exists.

  • Reply to Letter to the Editor: Association of Osteonecrosis and Failure of Hip Resurfacing Arthroplasty
    Clinical Orthopaedics & Related Research, 2010
    Co-Authors: Jozef Zustin, Michael Amling
    Abstract:

    We thank Doctors Kannan and Malhotra for their letter regarding our manuscript, Association of Osteonecrosis and Failure of Hip Resurfacing Arthroplasty [12]. They have challenged the evidence we presented suggesting osteonecrosis (ON) was associated with substantial failures of hip Resurfacing Arthroplasty [12]. More specifically, they questioned if (1) ON could not occur secondary to a periprosthetic fracture, (2) we analyzed the central section from the femoral remnant according to Howie et al. [5] to confirm the occurrence of superficial and generalized ON, and (3) patients with posttraumatic arthritis did not have ON develop before the Resurfacing procedure. We explained thoroughly the criteria for diagnosis of ON lesions in our study. We defined advanced ON lesions microscopically as the presence of trabeculae without stainable osteocytes, disorganized bone marrow, and bordering fibrosis, and by contact radiography of the specimens because of the observation of bordering sclerosis. Qui et al. [9] showed that remnants of apoptotic osteocytes may remain in situ for several weeks or months, recognizable by pyknotic nuclei using conventional light microscopy, but eventually the remnants become undetectable, leaving an apparently empty lacuna. This morphologic finding is considered a reliable sign that the osteocyte originally present has died [9]. Similarly, ON becomes recognizable radiographically the first several weeks or months after the fracture [6, 11]. Our definition of an advanced ON lesion also included the absence of an interface histiocyte reaction to cement as described by Bogoch et al. [1]. Therefore, we suggested ON probably was a cause of the specific type of periprosthetic fractures after a hip Resurfacing Arthroplasty (51 hips of a total of 85 failures associated with fracture) which occurred acutely in all cases with valid clinical data. Kannan and Malhotra correctly pointed out that previous retrieval analyses have shown varying rates of evidence of ON. Little et al. [7] and Steffen et al. [10] reported even greater occurrences of ON in hips revised for periprosthetic fractures after a Resurfacing Arthroplasty, however, the total number of retrieved hips was smaller. They suggested ON played a major role in periprosthetic fracture after the current generation hip Resurfacing Arthroplasty. In the study by Campbell et al. [3], the majority (70 of 98 hips) of revisions in their cohort were not attributable to fractures, and they detected ON in all five hips with an in situ time longer than 6 months, however, they did not discuss in detail the occurrence of ON in fractures that occurred within a short time. Based on our observations, we proposed that ON led to failure of the Resurfacing Arthroplasty predominantly within the first few months after implantation. Postnecrotic fractures in our study cohort were revised with a mean in situ time of 5.3 months. Although Forrest et al. [4] and McMahon et al. [8] radiographically analyzed well-functioning hips after a followup longer than 18 months and their cases were not analyzed morphologically, the comparison with our retrieval study does not seem to be reasonable. Furthermore, we also consider the comparison with the second-generation hip Resurfacing Arthroplasty not quite appropriate. There are several substantial differences in design and clinical outcome of the second as compared with the current generation hip Resurfacing Arthroplasty. Howie et al. [5] analyzed 72 cases mainly with intermediate- and long-term failures (none was revised within the first 6 months after implantation) and focused primarily on a possible association of ON with loosening. Bradley et al. [2] found two of 25 resurfaced hips revised for fracture had substantial regions of ON, and Bogoch et al. [1] found ON of the entire femoral head in three of four fractures. Therefore, our observations are consistent with those in the literature. Owing to design of the femoral component in the current generation hip Resurfacing Arthroplasty, it is impossible to analyze sections from the central areas as did Howie et al. [5]: the current generation femoral components are stemmed and the tissue from the central part of the femoral remnant is removed at implantation surgery. Nonetheless, we analyzed the tissue present between the superficial and central areas of the femoral remnant. By examining sections from three quadrants of each femoral remnant in their full length with a standardized sampling procedure, we believe we adequately addressed the question of sampling: the extent of ON was determined from the entire remnant rather than only the superficial and control portions. All ON lesions we observed were connected with the proximal surface of the bone remnant. We are not aware of any report of an isolated ON lesion after a hip Resurfacing Arthroplasty in the central or distal part of the femoral remnant without including its proximal areas. In addition, to avoid any possible misdiagnosis in cases with primary avascular necrosis of the femoral head, we excluded hips with this preoperative diagnosis. Drs Kannan and Malhotra correctly pointed out that in cases with posttraumatic arthritis, morphologic changes related to the initial traumatic event or its subsequent therapy might have led to ON before implantation. Preoperative biopsy information from hips before implantation was not available and could have been available only from the removed central region where the stem was located. As we examined only seven hips with a preoperative diagnosis of posttraumatic arthritis, this specific issue remained unanswered by our study. However, we found ON lesions in each hip from this group. Moreover, three of the six hips with posttraumatic arthritis with failed results attributable to periprosthetic fractures after the Resurfacing Arthroplasty were considered as having postnecrotic fractures. Because we did not have a control group (eg, examining for ON in patients without implant failure and/or femoral heads removed for conventional total hip Arthroplasty), any statements regarding possible relationships would be highly speculative. This question, however, might be adequately answered by clinical and radiographic studies. Based on our observations, we believe it is reasonable to presume the presence and the extent of ON after a Resurfacing Arthroplasty may be linked to complications from the Arthroplasty. Again we thank Drs Kannan and Malhotra for their insightful comments.

  • Intraosseous lymphocytic infiltrates after hip Resurfacing Arthroplasty
    Virchows Archiv, 2009
    Co-Authors: Jozef Zustin, Michael Hahn, Michael M. Morlock, Wolfgang Rüther, Michael Amling, Matthias Krause, Stefan Breer, Guido Sauter
    Abstract:

    To identify a possible role of lymphocytic infiltrates in failure mechanism of the metal-on-metal hip Resurfacing Arthroplasty, the extent of lymphocytic infiltration was compared with reasons for prosthesis failure in a series of retrieval specimens. One hundred eighty-one femoral head and neck remnants were subjected to thorough analysis of histological findings and clinical data. Lymphocytic infiltrates were considered weak to moderate in 52 (28.7%) and excessive in ten (5.5%) cases. Six cases with excessive lymphocytic infiltrates belonged to the group of 33 (18.2%) revisions without obvious cause (periprosthetic fracture, component loosening, and infection) for prosthesis failure. Excessive lymphocytic infiltrates were strongly linked to the presence of proliferative desquamative synovitis ( p  

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  • HIP Resurfacing Arthroplasty FOR HAEMOPHILIC ARTHROPATHY
    2018
    Co-Authors: Young Soo Chun, Yoon Je Cho, C.h. Lee, C.i. Bae, Kee Hyung Rhyu
    Abstract:

    PurposeThis study was performed to evaluate clinical and radiographic outcomes of Hip Resurfacing Arthroplasty for treatment of haemophilic hip arthropathy.Material & MethodBetween 2002 and 2013, 17 cases of hip Resurfacing arthroplasties were performed in 16 haemophilic patients (13 cases of haemophilia A, 2 cases of haemophilia B, 2 cases of von Willebrand disease). The average age of the patients was 32.5(range: 18∼52) years. The average follow up period from the operation was 6.3 (range: 2∼13) years. In this study, the subjects that completed follow-up were composed of 5 cases composed of patients who were treated with Conserve plus® hip Resurfacing system, 5 cases composed of patients who were treated with Durom® hip Resurfacing system, 4 cases who were treated with ASR® hip Resurfacing system, and 3 cases who were treated with Birmingham® hip Resurfacing system. The Modified Harris hip score, the range of motion of the hip joint, perioperative coagulation factor requirements and complications associ...

  • Radiological Changes After Metal on Metal Resurfacing Arthroplasty
    Journal of Bone and Joint Surgery-british Volume, 2013
    Co-Authors: Yoon Je Cho, Young Soo Chun, Kee Hyung Rhyu, Joo-hyun Lee, Sangjoon Kwak, Ye Yeon Won, Myung Chul Yoo
    Abstract:

    Purpose To evaluate the radiological changes after metal on metal Resurfacing Arthroplasty. Materials and Methods Between December 1998 and August 2004, 166 hips in 150 patients who underwent metal Resurfacing Arthroplasty and followed up more than 4 years. Their mean age at the time of operation was 37.3 years(range, 15–68 years) and mean period of follow-up was 6.1 years(range, 48–95 months). The cause of Arthroplasty included 115 avascular necrosis, 43 osteoarthritis, 7 ankylosing spondylitis, 1 haemophilic arthropathy. All patients had anteroposterior, translateral radiographs of the hip made preoperatively and each follow-up visit, and we analyzed radiographic findings such as radiolucencies or impingement signs around implant, neck narrowing and heterotopic ossification. Results There was a no significant difference between preoperative and postoperative Harris hip score and range of motion. The mean stem-shaft angle was 137.4°, and 55.4% were ranged 130° to 140°. The mean inclination of acetabular component was 44.9°. There were no radiolucent lines or osteolytic lesion around the acetabular components, but 3 hips showed radiolucency around the head-neck junction(1.8%) and 4 hips showed radiolucent line around the stem (2.4%). 12 hips had impingement signs around the head-neck junction (7.2%), and 2 cases showed neck narrowing (1.2%). 3 cases had some heterotopic ossification (1.8%). In 12 cases with impingement signs, the stem-shaft angle and inclination of acetabular component were lower than control group. Pseudotumor was not found in this cohort. Conclusions This study demonstrates no serious radiological problems till the midterm follow-up after Resurfacing Arthroplasty, but osteolytic lesion such as radiolucent line around head-neck junction, neck narrowing can be a potential cause of failure in future. Even though the radiolucent line around stem of femoral component revealed no subjective symptom yet, it suggests the micromotion of femoral component which can lead to femoral component loosening. The most common radiological findings, impingement signs, seem not to have clinical significance.

  • Impingement between the acetabular cup and the femoral neck after hip Resurfacing Arthroplasty.
    Journal of Bone and Joint Surgery, 2011
    Co-Authors: Myung Chul Yoo, Yoon Je Cho, Young Soo Chun, Kee Hyung Rhyu
    Abstract:

    Background: Loosening, femoral neck fracture, and metal ion release have been well documented after hip Resurfacing Arthroplasty, but impingement between the acetabular cup and the femoral neck has not. The goal of this study was to analyze radiographic findings that were presumed to represent impingement of the neck after hip Resurfacing Arthroplasty, and to describe the mechanism of impingement. Methods: Of the 635 hips (579 patients) that underwent hip Resurfacing Arthroplasty between September 1998 and May 2008, forty hips (6.3%) with positive radiographic findings were available for this study. The mean age of the patients was 34.9 years and there were thirty-five men and five women. The average follow-up was sixty-eight months (twenty-four to 132 months). Radiographic evaluation included an analysis of neck-shaft angle, inclination of the acetabular cup, head-neck ratio, lateral protrusion of the cup, anterior protrusion of the cup, and stem angle to the axis of the femoral neck. Results: Impingement between the acetabular cup and the femoral neck occurred in 6.3% of hips and appeared at an average of seven months after surgery. There was no further change two years postoperatively. The impingement findings did not correlate with the clinical outcome, but all instances of impingement were located in the lateral or anterolateral part of the femoral neck along the arc from the center of the femoral head to the lateral edge of the socket. No significant factors were found to be related to the occurrence of impingement. Conclusions: Femoral-neck impingement should be differentiated from notching, narrowing, stress-shielding, or osteolysis of the femoral neck. Although we found no significant factors to explain the impingement found in the hips in our study, it appears that repetitive extreme motion of the involved hip and malposition of the implants can cause impingement after hip Resurfacing Arthroplasty. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

  • Hip Resurfacing Arthroplasty in Patients with Rheumatoid Arthritis
    Journal of Rheumatic Diseases, 2011
    Co-Authors: Yoon Je Cho, Young Soo Chun, Kang-il Kim, Kee Hyung Rhyu, Myung Chul Yoo, Hyuk Hong
    Abstract:

    Objective. This study analyzed the midterm results of hip Resurfacing Arthroplasty in patients with rheumatoid arthritis. Methods. Between October of 2003 and September of 2008, 13 consecutive hips that were treated with hip Resurfacing Arthroplasty due to rheumatoid arthritis were analyzed. The average follow up period was 48.6 months and the mean age at the time of operation was 35.9 years old. The mean BMI at the operation was 23.2 kg/m 2 . The implanted prostheses were the Conserve Plus system in five hips, the Birmingham hip Resurfacing system in four hips and the Durom system in four hips. The results were clinically evaluated with the Harris hip score, the UCLA activity score, hip or thigh pain, the limb length discrepancy and the range of motion. As radiological evaluation, we observed the patterns of bone remodeling and complications such as femoral neck fracture, loosening and osteolysis. Results. The average Harris hip score improved from 62.2 to 98.9 at the final visit. The range of motion improved to 0 o in flexion contracture, 118.1 o in further flexion, 22.7 o

  • Impingement between the acetabular cup and the femoral neck after hip Resurfacing Arthroplasty.
    The Journal of bone and joint surgery. American volume, 2011
    Co-Authors: Myung Chul Yoo, Yoon Je Cho, Young Soo Chun, Kee Hyung Rhyu
    Abstract:

    Loosening, femoral neck fracture, and metal ion release have been well documented after hip Resurfacing Arthroplasty, but impingement between the acetabular cup and the femoral neck has not. The goal of this study was to analyze radiographic findings that were presumed to represent impingement of the neck after hip Resurfacing Arthroplasty, and to describe the mechanism of impingement. Of the 635 hips (579 patients) that underwent hip Resurfacing Arthroplasty between September 1998 and May 2008, forty hips (6.3%) with positive radiographic findings were available for this study. The mean age of the patients was 34.9 years and there were thirty-five men and five women. The average follow-up was sixty-eight months (twenty-four to 132 months). Radiographic evaluation included an analysis of neck-shaft angle, inclination of the acetabular cup, head-neck ratio, lateral protrusion of the cup, anterior protrusion of the cup, and stem angle to the axis of the femoral neck. Impingement between the acetabular cup and the femoral neck occurred in 6.3% of hips and appeared at an average of seven months after surgery. There was no further change two years postoperatively. The impingement findings did not correlate with the clinical outcome, but all instances of impingement were located in the lateral or anterolateral part of the femoral neck along the arc from the center of the femoral head to the lateral edge of the socket. No significant factors were found to be related to the occurrence of impingement. Femoral-neck impingement should be differentiated from notching, narrowing, stress-shielding, or osteolysis of the femoral neck. Although we found no significant factors to explain the impingement found in the hips in our study, it appears that repetitive extreme motion of the involved hip and malposition of the implants can cause impingement after hip Resurfacing Arthroplasty.