BACKGROUND The use of uncemented cups during total hip arthroplasty(THA)has gained popularity in recent years.The Robert Mathys(RM)pressfit cup,an uncemented monoblock implant is expected to preserve bone density due ...BACKGROUND The use of uncemented cups during total hip arthroplasty(THA)has gained popularity in recent years.The Robert Mathys(RM)pressfit cup,an uncemented monoblock implant is expected to preserve bone density due to its composition and external surface,while reducing backside wear with its monoblock construction.These factors should lead to a high survival rate of the implant.AIM To evaluate the mid-term survival and functional outcome of the RM Pressfit cup in a large study population.METHODS Between 2011 and 2020,we included 1324 patients receiving a primary THA using the RM pressfit cup.Final clinical follow-up was performed at 2 years postoperatively with the Dutch arthroplasty register used to assess implant status thereafter.Revision for acetabular failure and reason for revision were reported to evaluate implant survival,while the hip disability and osteoarthritis outcome score(HOOS)scores were used to assess functional outcome.RESULTS The mean age at surgery was 64.9 years.The mean follow-up was 4.6 years.Of the 1324 THAs performed,13 needed cup revisions within 5 years after index THA:5 due to aseptic loosening,6 due to infection,2 due to dislocation and 2 due to other causes.This resulted in a 5-year cup survival of 98.8%(95%CI:98.1-99.5).Nine of the cup revisions occurred within the first year after index THA.HOOS scores increased significantly in all domains during the first year and levelled out during the second year.CONCLUSION In the present study,the RM pressfit cup demonstrated excellent clinical outcomes at mid-term follow-up;however,future studies are needed to assess the long-term outcomes of this acetabular implant.展开更多
This paper presents a theoretical method and a finite element method to describe wellhead movement and uncemented casing strength in offshore oil and gas wells.Parameters considered in the theoretical method include o...This paper presents a theoretical method and a finite element method to describe wellhead movement and uncemented casing strength in offshore oil and gas wells.Parameters considered in the theoretical method include operating load during drilling and completion and the temperature field,pressure field and the end effect of pressure during gas production.The finite element method for multistring analysis is developed to simulate random contact between casings.The relevant finite element analysis scheme is also presented according to the actual procedures of drilling,completion and gas production.Finally,field cases are presented and analyzed using the proposed methods.These are four offshore wells in the South China Sea.The calculated wellhead growths during gas production are compared with measured values.The results show that the wellhead subsides during drilling and completion and grows up during gas production.The theoretical and finite element solutions for wellhead growth are in good agreement with measured values and the deviations of calculation are within 10％.The maximum von Mises stress on the uncemented intermediate casing occurs during the running of the oil tube.The maximum von Mises stress on the uncemented production casing,calculated with the theoretical method occurs at removing the blow-out-preventer （BOP） while that calculated with the finite element method occurs at gas production.Finite element solutions for von Mises stress are recommended and the uncemented casings of four wells satisfy strength requirements.展开更多
Total hip replacement(THR) is a successful and reliable operation for both relieving pain and improving function in patients who are disabled with end stage arthritis.The ageing population is predicted to significantl...Total hip replacement(THR) is a successful and reliable operation for both relieving pain and improving function in patients who are disabled with end stage arthritis.The ageing population is predicted to significantly increase the requirement for THR in patients who have a higher functional demand than those of the past. Uncemented THR was introduced to improve the long term results and in particular the results in younger, higher functioning patients. There has been controversy about the value of uncemented compared to cemented THR although there has been a world-wide trend towards uncemented fixation. Uncemented acetabular fixation has gained wide acceptance, as seen in the increasing number of hybrid THR in joint registries, but there remains debate about the best mode of femoral fixation.In this article we review the history and current worldwide registry data, with an in-depth analysis of the New Zealand Joint Registry, to determine the results of uncemented femoral fixation in an attempt to provide an evidence-based answer as to the value of this form of fixation.展开更多
BACKGROUND The popularity of uncemented stems in revision total hip arthroplasty(THA)has increased in the last decade.AIM To assess the outcomes of both cemented and uncemented stems after mid-term follow up.METHODS T...BACKGROUND The popularity of uncemented stems in revision total hip arthroplasty(THA)has increased in the last decade.AIM To assess the outcomes of both cemented and uncemented stems after mid-term follow up.METHODS This study was performed following both the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement and the Cochrane Handbook for systematic reviews and meta-analysis guidelines.Articles were chosen irrespective of country of origin or language utilized for the article full texts.This paper included studies that reviewed revision THA for both cemented or uncemented long stems.RESULTS Three eligible studies were included in the meta-analysis.Analysis was conducted by using Review Manager version 5.3.We computed the risk ratio as a measure of the treatment effect,taking into account heterogeneity.We used random-effect models.There were no significant differences found for intraoperative periprosthetic fractures[risk ratio(RR)=1.25;95%confidence interval(CI):0.29-5.32;P=0.76],aseptic loosening(RR=2.15,95%CI:0.81-5.70;P=0.13),dislocation rate(RR=0.50;95%CI:0.10-2.47;P=0.39),or infection rate(RR=0.99,95%CI:0.82-1.19;P=0.89),between the uncemented and the cemented long stems for revision THA after mid-term follow-up.CONCLUSION This study has evaluated the mid-term outcomes of both cemented and uncemented stems at first-time revision THA.In summary,there were no significant differences in the dislocation rate,aseptic loosening,intraoperative periprosthetic fracture and infection rate between the two cohorts.展开更多
BACKGROUND Bilateral hip disorder is a common finding that can occur in approximately 42%of the population with osteoarthritis.It is estimated that 25%individuals with osteoarthritis requiring total hip replacement(TH...BACKGROUND Bilateral hip disorder is a common finding that can occur in approximately 42%of the population with osteoarthritis.It is estimated that 25%individuals with osteoarthritis requiring total hip replacement(THR)may require a bilateral replacement.This has resulted in the test of the greatest strategy to run single staged bilateral hip replacement while addressing the outcomes to achieve swift and cost-effective patient recovery.AIM To assess the outcomes and cost effectiveness of bilateral THR(B/L THR)at our tertiary care hospital.METHODS Retrospective observational cross-sectional study was undertaken from Jan 2018 to July 2023 to assess the clinical outcomes of patients who underwent single stage B/L THR.RESULTS Data of 75 patients were analysed.The mean age was 36 years.Our complication rate was 4.0%including acute coronary syndrome,intra-operative acetabular fracture and paralytic ileus.The re-admission rate was 4%.CONCLUSION The choice of sequential or bilateral hip replacement is controversial.While,our study showed that bilateral hip replacement is safe and cost effective.As surgeons,we were careful in patient selection(low American Society of Anesthesiologist score).Though more than 50%of our B/L THR patients were obese[body mass index(BMI)>25],our outcomes were equivalent to normal BMI patients with lower risk of complication as well as early ambulation.Systemic complication deep vein thrombosis and pulmonary embolism were handled prophylactively by close monitoring,use of mechanical and pharmacological agents along with anticoagulants.Patients who require THR,often require them bilaterally and single stage replacement thus offers early restoration of an individual into their activities of daily living with minimal complications.Our findings support the use of single-stage B/L THR as a viable option for bilateral hip disorders,having favourable outcomes.展开更多
BACKGROUND Total hip arthroplasty(THA)has increased along with an increasing demand for improved quality of life.Combined with prolonged life expectancy,the number of revision surgeries is expected to increase.Stress ...BACKGROUND Total hip arthroplasty(THA)has increased along with an increasing demand for improved quality of life.Combined with prolonged life expectancy,the number of revision surgeries is expected to increase.Stress shielding is a significant issue with traditional femoral stems used in THA,making revision surgeries particularly challenging in younger patients.This has sparked renewed interest in studying safety and functional outcomes of short metaphyseal femoral stems,which have the potential to alleviate these challenges and simplify revision surgeries.AIM To evaluate the long-term outcomes of short-stem THA.METHODS A total of 124 hips that underwent THA using the short femoral stem(TRILOCK®Depuy)between May 2006 and November 2008 were included in this study.Patients were followed for a period of 15 years.Outcomes were assessed in terms of pain relief,hip joint range of motion,improvement in mobility,and functional outcomes using the modified Harris Hip Score,Oxford hip score,and Western Ontario and McMaster Universities Osteoarthritis index score.RESULTS A total of 124 hips in 98 patients were evaluated.Significant improvements in functional outcomes were observed over the 15-year follow-up period,with no cases of subsidence,implant loosening,or complications necessitating revision surgery.The only complication reported was heterotopic ossification in 1 patient.CONCLUSION Short metaphyseal stems provide better functional outcomes with early mobilization,and its long-term follow-up without subsidence,implant loosening,or proximal femoral bone loss simplifies revision surgery in younger patients.展开更多
Heterotopic ossification (HO) may cause pain, and can lead to loss of hip motion after total hip arthroplasty (THA). There is evidence that pulsed lavage may lower the incidence of HO formation. We assessed the effect...Heterotopic ossification (HO) may cause pain, and can lead to loss of hip motion after total hip arthroplasty (THA). There is evidence that pulsed lavage may lower the incidence of HO formation. We assessed the effect of pulsed lavage on the incidence of HO in 87 male patients after THA. All patients received an uncemented THA through a posterolateral approach. 39 patients were treated with pulsed lavage (index group) and 48 males were treated without pulsed lavage (historical control group, matched on aetiology, gender, surgical approach and type of prosthesis). Both groups followed the same postoperative treatment regimen. HO severity was scored in both groups according to the Brooker classification by three blinded orthopaedic surgeons one year postoperatively. Good inter-observer agreement (Kappa 0.7) for scoring HO was found. The incidence of HO (51%) in the index group did not differ significantly (p = 0.53) from the control group (58%). However, the incidence of clinically relevant HO (Brooker grades 3 and 4) was significantly lower (p = 0.04) in the index group (3%) as compared to the control group (17%). These results suggest a beneficial effect of pulsed lavage on the incidence of severe heterotopic ossification after cementless THA in male patients.展开更多
文摘BACKGROUND The use of uncemented cups during total hip arthroplasty(THA)has gained popularity in recent years.The Robert Mathys(RM)pressfit cup,an uncemented monoblock implant is expected to preserve bone density due to its composition and external surface,while reducing backside wear with its monoblock construction.These factors should lead to a high survival rate of the implant.AIM To evaluate the mid-term survival and functional outcome of the RM Pressfit cup in a large study population.METHODS Between 2011 and 2020,we included 1324 patients receiving a primary THA using the RM pressfit cup.Final clinical follow-up was performed at 2 years postoperatively with the Dutch arthroplasty register used to assess implant status thereafter.Revision for acetabular failure and reason for revision were reported to evaluate implant survival,while the hip disability and osteoarthritis outcome score(HOOS)scores were used to assess functional outcome.RESULTS The mean age at surgery was 64.9 years.The mean follow-up was 4.6 years.Of the 1324 THAs performed,13 needed cup revisions within 5 years after index THA:5 due to aseptic loosening,6 due to infection,2 due to dislocation and 2 due to other causes.This resulted in a 5-year cup survival of 98.8%(95%CI:98.1-99.5).Nine of the cup revisions occurred within the first year after index THA.HOOS scores increased significantly in all domains during the first year and levelled out during the second year.CONCLUSION In the present study,the RM pressfit cup demonstrated excellent clinical outcomes at mid-term follow-up;however,future studies are needed to assess the long-term outcomes of this acetabular implant.
基金financial support from the National Key Sci-Tech Major Special Item(No.2011ZX05026-001)Program for Changjiang Scholars and Innovative Research Team in University(IRT1086)
文摘This paper presents a theoretical method and a finite element method to describe wellhead movement and uncemented casing strength in offshore oil and gas wells.Parameters considered in the theoretical method include operating load during drilling and completion and the temperature field,pressure field and the end effect of pressure during gas production.The finite element method for multistring analysis is developed to simulate random contact between casings.The relevant finite element analysis scheme is also presented according to the actual procedures of drilling,completion and gas production.Finally,field cases are presented and analyzed using the proposed methods.These are four offshore wells in the South China Sea.The calculated wellhead growths during gas production are compared with measured values.The results show that the wellhead subsides during drilling and completion and grows up during gas production.The theoretical and finite element solutions for wellhead growth are in good agreement with measured values and the deviations of calculation are within 10％.The maximum von Mises stress on the uncemented intermediate casing occurs during the running of the oil tube.The maximum von Mises stress on the uncemented production casing,calculated with the theoretical method occurs at removing the blow-out-preventer （BOP） while that calculated with the finite element method occurs at gas production.Finite element solutions for von Mises stress are recommended and the uncemented casings of four wells satisfy strength requirements.
文摘Total hip replacement(THR) is a successful and reliable operation for both relieving pain and improving function in patients who are disabled with end stage arthritis.The ageing population is predicted to significantly increase the requirement for THR in patients who have a higher functional demand than those of the past. Uncemented THR was introduced to improve the long term results and in particular the results in younger, higher functioning patients. There has been controversy about the value of uncemented compared to cemented THR although there has been a world-wide trend towards uncemented fixation. Uncemented acetabular fixation has gained wide acceptance, as seen in the increasing number of hybrid THR in joint registries, but there remains debate about the best mode of femoral fixation.In this article we review the history and current worldwide registry data, with an in-depth analysis of the New Zealand Joint Registry, to determine the results of uncemented femoral fixation in an attempt to provide an evidence-based answer as to the value of this form of fixation.
文摘BACKGROUND The popularity of uncemented stems in revision total hip arthroplasty(THA)has increased in the last decade.AIM To assess the outcomes of both cemented and uncemented stems after mid-term follow up.METHODS This study was performed following both the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement and the Cochrane Handbook for systematic reviews and meta-analysis guidelines.Articles were chosen irrespective of country of origin or language utilized for the article full texts.This paper included studies that reviewed revision THA for both cemented or uncemented long stems.RESULTS Three eligible studies were included in the meta-analysis.Analysis was conducted by using Review Manager version 5.3.We computed the risk ratio as a measure of the treatment effect,taking into account heterogeneity.We used random-effect models.There were no significant differences found for intraoperative periprosthetic fractures[risk ratio(RR)=1.25;95%confidence interval(CI):0.29-5.32;P=0.76],aseptic loosening(RR=2.15,95%CI:0.81-5.70;P=0.13),dislocation rate(RR=0.50;95%CI:0.10-2.47;P=0.39),or infection rate(RR=0.99,95%CI:0.82-1.19;P=0.89),between the uncemented and the cemented long stems for revision THA after mid-term follow-up.CONCLUSION This study has evaluated the mid-term outcomes of both cemented and uncemented stems at first-time revision THA.In summary,there were no significant differences in the dislocation rate,aseptic loosening,intraoperative periprosthetic fracture and infection rate between the two cohorts.
文摘BACKGROUND Bilateral hip disorder is a common finding that can occur in approximately 42%of the population with osteoarthritis.It is estimated that 25%individuals with osteoarthritis requiring total hip replacement(THR)may require a bilateral replacement.This has resulted in the test of the greatest strategy to run single staged bilateral hip replacement while addressing the outcomes to achieve swift and cost-effective patient recovery.AIM To assess the outcomes and cost effectiveness of bilateral THR(B/L THR)at our tertiary care hospital.METHODS Retrospective observational cross-sectional study was undertaken from Jan 2018 to July 2023 to assess the clinical outcomes of patients who underwent single stage B/L THR.RESULTS Data of 75 patients were analysed.The mean age was 36 years.Our complication rate was 4.0%including acute coronary syndrome,intra-operative acetabular fracture and paralytic ileus.The re-admission rate was 4%.CONCLUSION The choice of sequential or bilateral hip replacement is controversial.While,our study showed that bilateral hip replacement is safe and cost effective.As surgeons,we were careful in patient selection(low American Society of Anesthesiologist score).Though more than 50%of our B/L THR patients were obese[body mass index(BMI)>25],our outcomes were equivalent to normal BMI patients with lower risk of complication as well as early ambulation.Systemic complication deep vein thrombosis and pulmonary embolism were handled prophylactively by close monitoring,use of mechanical and pharmacological agents along with anticoagulants.Patients who require THR,often require them bilaterally and single stage replacement thus offers early restoration of an individual into their activities of daily living with minimal complications.Our findings support the use of single-stage B/L THR as a viable option for bilateral hip disorders,having favourable outcomes.
文摘BACKGROUND Total hip arthroplasty(THA)has increased along with an increasing demand for improved quality of life.Combined with prolonged life expectancy,the number of revision surgeries is expected to increase.Stress shielding is a significant issue with traditional femoral stems used in THA,making revision surgeries particularly challenging in younger patients.This has sparked renewed interest in studying safety and functional outcomes of short metaphyseal femoral stems,which have the potential to alleviate these challenges and simplify revision surgeries.AIM To evaluate the long-term outcomes of short-stem THA.METHODS A total of 124 hips that underwent THA using the short femoral stem(TRILOCK®Depuy)between May 2006 and November 2008 were included in this study.Patients were followed for a period of 15 years.Outcomes were assessed in terms of pain relief,hip joint range of motion,improvement in mobility,and functional outcomes using the modified Harris Hip Score,Oxford hip score,and Western Ontario and McMaster Universities Osteoarthritis index score.RESULTS A total of 124 hips in 98 patients were evaluated.Significant improvements in functional outcomes were observed over the 15-year follow-up period,with no cases of subsidence,implant loosening,or complications necessitating revision surgery.The only complication reported was heterotopic ossification in 1 patient.CONCLUSION Short metaphyseal stems provide better functional outcomes with early mobilization,and its long-term follow-up without subsidence,implant loosening,or proximal femoral bone loss simplifies revision surgery in younger patients.
文摘Heterotopic ossification (HO) may cause pain, and can lead to loss of hip motion after total hip arthroplasty (THA). There is evidence that pulsed lavage may lower the incidence of HO formation. We assessed the effect of pulsed lavage on the incidence of HO in 87 male patients after THA. All patients received an uncemented THA through a posterolateral approach. 39 patients were treated with pulsed lavage (index group) and 48 males were treated without pulsed lavage (historical control group, matched on aetiology, gender, surgical approach and type of prosthesis). Both groups followed the same postoperative treatment regimen. HO severity was scored in both groups according to the Brooker classification by three blinded orthopaedic surgeons one year postoperatively. Good inter-observer agreement (Kappa 0.7) for scoring HO was found. The incidence of HO (51%) in the index group did not differ significantly (p = 0.53) from the control group (58%). However, the incidence of clinically relevant HO (Brooker grades 3 and 4) was significantly lower (p = 0.04) in the index group (3%) as compared to the control group (17%). These results suggest a beneficial effect of pulsed lavage on the incidence of severe heterotopic ossification after cementless THA in male patients.
