Excision of trochanteric bursa during total hip replacement:Does it reduce the incidence of post-operative trochanteric bursitis?

BACKGROUND Trochanteric bursitis is a common complication following total hip replacement(THR),and it is associated with high level of disability and poor quality of life.Excision of the trochanteric bursa prophylactically during THR could reduce the occurrence of post-operative trochanteric bursitis.AIM To evaluate whether synchronous trochanteric bursectomy at the time of THR affects the incidence of post-operative trochanteric bursitis.METHODS This retrospective cohort study was conducted in the secondary care setting at a large district general hospital.Between January 2010 and December 2020,954 patients underwent elective primary THR by two contemporary arthroplasty surgeons,one excising the bursa and the other not(at the time of THR).All patients received the same post-operative rehabilitation and were followed up for 1 year.We reviewed all cases of trochanteric bursitis over this 11-year period to determine the incidence of post-THR bursitis.Two proportion Z-test was used to compare incidences of trochanteric bursitis between groups.RESULTS 554 patients underwent synchronous trochanteric bursectomy at the time of THR whereas 400 patients did not.A total of 5 patients(incidence 0.5%)developed trochanteric bursitis following THR;4 of whom had undergone bursectomy as part of their surgical approach,1 who had not.There was no statistically significant difference between the two groups(Z value 1.00,95%CI:-0.4%to 1.3%,P=0.32).There were also 8 other patients who had both trochanteric bursitis and hip osteoarthritis prior to their THR;all of whom were treated with THR and synchronous trochanteric bursectomy,and 7 had resolution of their lateral buttock pains but 1 did not.CONCLUSION Synchronous trochanteric bursectomy during THR does not materially affect the incidence of post-operative bursitis.However,it is successful at treating patients with known trochanteric bursitis and osteoarthritis requiring THR.

Cementless Buechel-Pappas Resurfacing Total Hip Replacement: A 45-Year Personal Journey to Overcome Wear, Osteolysis, Loosening and Femoral Neck Fractures

Background: Resurfacing-type total hip replacement (THR) has been successfully developed over the past 50 years through collaborative efforts between engineers and surgeons. Much of the development was pursued by individuals or groups, each of which participated in adding further refinements to the implants, instruments and surgical procedures, thus minimizing the serious problems of wear, osteolysis, loosening and femoral neck fractures. The purpose of this study is to explore the development process to optimize the resurfacing total hip replacement into its current application. Methods: In the early 1980s, cementless resurfacing implants were developed using “thin shell” technology to minimize bony resection of the acetabulum and femoral head. Femoral components utilized short, non-porous coated, tapered straight stems to reduce shear stresses in the femoral neck to prevent fractures and stress shielding, while mechanically stabilizing and aligning the components. Acetabular components were anatomically designed to be recessed inside bony borders to avoid neck-cup impingement and loosening. Initially, ultrahigh molecular weight polyethylene (UHMWPE) was used as a bearing, but due to high levels of wear and osteolysis, it was replaced by wear-resistant highly crossed-linked polyethylene (HXLPE) in 2008. Results: Use of HXLPE as a bearing material in both Co-Cr-Mo and titanium nitride (TiN) ceramic-coated resurfacing implants has led to excellent patient outcomes for more than 10 years. In clinical studies, 87% of patients with bilateral total hip replacements prefer their resurfacing-type total hip over their stem-type total hip. The author’s own personal resurfacing total hips, now at 8 and 5 years, respectively, provide “normal” function and no radiographic osteolysis. Conclusions: After 45 years of active evaluation, including mechanical design considerations, prosthetic design development, clinical and radiographic analysis of results, as well as availability of components cleared by the FDA 510 K process, the author has stated a personal preference for the BP Resurfacing Hip System. His excellent mid-term results in both of his resurfaced hips are similar to the long-term results presented in published studies.

Nomogram to predict postoperative complications in elderly with total hip replacement

BACKGROUND By analyzing the risk factors of postoperative complications in elderly patients with hip replacement,We aimed to develop a nomogram model based on preoperative and intraoperative variables and verified the sensitivity and specificity for risk stratification of postoperative complications in elderly with total hip replacement patients.AIM To develop a nomogram model for risk stratification of postoperative complications in elderly with total hip replacement patients.METHODS A total of 414 elderly patients who underwent surgical treatment for total hip replacement hospitalized at the Affiliated Hospital of Guangdong Medical University from March 1,2017 to August 31,2019 were included into this study.Univariate and multivariate logistic regression were conducted to identify independent risk factors of postoperative complication in the 414 patients.A nomogram was developed by R software and validated to predict the risk of postoperative complications.RESULTS Multivariate logistic regression analysis revealed that age(OR=1.05,95%CI:1.00-1.09),renal failure(OR=0.90,95%CI:0.83-0.97),Type 2 diabetes(OR=1.05,95%CI:1.00-1.09),albumin(ALB)(OR=0.91,95%CI:0.83-0.99)were independent risk factors of postoperative complication in elderly patients with hip replacement(P<0.05).For validation of the nomogram,receive operating characteristic curve revealed that the model predicting postoperative complication in elderly patients with hipreplacement was the area under the curve of 0.8254 (95%CI: 0.78-0.87), the slope of the calibrationplot was close to 1 and the model passed Hosmer-Lemeshow goodness of fit test (χ^(2) = 10.16, P =0.4264), calibration in R E_(max) = 0.176, E_(avg) = 0.027, which all demonstrated that the model was ofgood accuracy.CONCLUSIONThe nomogram predicting postoperative complications in patients with total hip replacementconstructed based on age, type 2 diabetes, renal failure and ALB is of good discrimination andaccuracy, which was of clinical significance.

Total hip replacement using MINIMA^(■)short stem:A short-term follow-up study

BACKGROUND Total hip replacement has become one of the most successful orthopaedic procedures.The length of the femoral stem constitutes one of the most important geometrical and mechanical features of the prosthesis.Several different implants are currently available but data are limited concerning the clinical results for some of these implants.AIM To report the short-term clinical and radiological results of a novel squared section,tapered design–with four conicity-short stem in total hip replacement.METHODS This is a retrospective study of a prospectively collected data using of MINIMA?short stem in 61 consecutive patients with at least 1 year follow-up.The collected data included patients’demographics,type of arthritis,bone morphology,perioperative data,clinical results using Harris Hip Score,EuroQol(EQ-5D),pain score and satisfaction rate,complications and radiological results.RESULTS Total 61 patients were included in our study with a mean age of 56 years of age(range 25-73 years).The majority of them(68.6%)were women,thirty seven patients(56.9%)were less than 60 years of age and almost half of patients(45.1%)suffered from secondary osteoarthritis(hip dysplasia,osteonecrosis,etc.).The mean time of follow-up examination was 33.4 mo(2.8 years)with a range of 12-57 months(1-4.8 years).In 35 patients(56.9%)the follow-up examination was more than 3 years.No major complications such as revision,periprosthetic fracture,dislocation or infection were presented.Re-admission 90 d postoperatively or laterwas deemed unnecessary for any reason regarding the operation.Respectively,the mean pain score,mean Harris hip score,and mean EQ-5D were improved from 6.3,58.7 and 77.3 preoperatively to 0.1,95.1,and 79.8 postoperatively.The Satisfaction rate at the final follow-up was 9.9(SD 0.3,range 8.0-10.0).All stems were classified as stable bone ingrowth and no radiolucent lineswere revealed in any of the modified Gruens’zone at the postoperative Xrays.Stem subsidence was within acceptable limits and the incidence of distal cortical hypertrophy was relatively low.CONCLUSION The clinical and radiological results concerning the MINIMA?short stem are excellent according to this first report of this specific design of the short femoral stems.Because of the small number of cases and short-term follow-up of this study,a longer follow up time and more patients’enrollment is required.

Effect of sevoflurane inhalation and general anesthesia on serum IL-6 and S100β levels and coagulation function in elderly patients undergoing total hip replacement

Objective:To investigate the effects of sevoflurane inhalation general anesthesia on serum IL-6,brain injury protein S100βand coagulation function in elderly patients undergoing total hip arthroplasty.Method:From May 2017 to May 2019,84 patients,age 60-75 underwent total hip arthroplasty in our hospital.were randomly divided into two groups:group A(n=42)and group B(n=42).Group A was maintained with sevoflurane inhalation by general anesthesia and group B with propofol by intravenous anesthesia.The surgical related indexes and postoperative complications in the two groups were compared.The level of serum IL-6,S100β,Coagulation function index[platelet count(PLT),Fibrinogen(FIB),plasma D-dimer(D-D),activated partial enzyme activity time(APTT),prothrombin time(PT)],MMSE score and MoCA score were compared between two groups before and after operation.Results:There was no significant difference in anesthesia time,operation time,intraoperative bleeding and postoperative drainage(P>0.05).1h,1d and 7d after operation,the level of PLT,D-D and FIB in group A were significantly lower than that in group B(P<0.05),PT and APTT were significantly higher than that in group B(P<0.05).1h,1d and 7d after operation,the level of IL-6,S100βin group A were significantly lower than that in group B(P<0.05).1d after operation,the MMSE and MoCA scores in group B were significantly lower than those in group A(P<0.05).The incidence of lower extremity deep venous thrombosis(2.38%)and cognitive impairment(2.38%)in group A was lower than that in group B(14.29%,16.67%)(t1=3.896,P1=0.048;t2=4.974,P2=0.026).Conclusion:sevoflurane anesthesia can reduce the incidence of deep venous thrombosis and cognitive impairment of the lower extremity after operation in elderly patients with thr,stabilize the coagulation index of patients,and downregulate the expression of il-6 and S100β.

Reduction in pulmonary complications in high risk patients undergoing surgery for total hip replacement under general anesthesia by preoperative intensive inspiratory muscle training:A randomized controlled clinical trial

Objective： To evaluate the effects of preoperative inspiratory muscle training （IMT） on the incidence of atelectasis in patients at high risk of postoperative pulmonary complications scheduled for elective total hip replacement surgery under general anesthesia. Methods： Thirty two high-risk patients undergoing elective total hip replacement surgery under general anesthesia were chosen from Nanjing Medical University, Affiliated Nanjing First Hospital. In this single-blind randomized controlled clinical triM, patients were randomly assigned to receive preoperative inspiratory muscle training or conventional treatment （CT）. The major effectiveness outcome variables were atelectasis and duration of postoperative hospitalization. Results： Both groups were comparable prior to surgery. Seven patients in the CT group and 3 in the IMT group developed atelectasis （P = 0.25）. Median duration of postoperative hospitalization was 13 days （range, 10～17 days） in the IMT group versus 16 days （range, 11～23 days） in the CT group （Mann- Whitney U statistics, Z = -2.22, P = 0.03）. Mean postoperative inspiratory pressure was 5% higher in the IMT group. Conclusion： Preoperative intensive inspiratory muscle training appears to reduce the incidence of atelectasis and duration of postoperative hospitalization in patients at high risk of developing postoperative pulmonary complications who were scheduled for elective total hip replacement surgery under general anesthesia.

Preliminary Report on Phenom^®Femoral Component in Total Hip Replacement: The Correlation between Outcome Scores in a Cross-Seccional Study

Background: The main purpose of the present study was to assess the short term performance of a cementless femoral stem in total hip replacement. Methods: Cross-sectional observational study of a 48-patient cohort with Phenom? femoral stems implanted between June 1, 2014 and September 1, 2018, to determine clinical performance, stability, and radiographic osseointegration. Patients were followed-up from 13 to 76 months (mean: 44.5 months) and assessed using the Harris Hip Score-HHS, the Hip Disability and Osteoarthritis Outcome Score-HOOS and radiographs. Results: All stems were radiologically stable. Mean Harris Hip Score was 89.8 and the HOOS was 80.4. No statistical differences were observed among patients with different diagnoses. Conclusions: The short-term results revealed satisfactory clinical outcomes and radiological signs of implant stability in all cases. Using two functional scores was useful in detecting biases and a low to moderate agreement was found between the scores.

Participating in health care for total hip replacement patients:an integrative review

In recent years,with the continuous improvement of people's health requirements,the awareness of participating in disease diagnosis and treatment has also been constantly enhanced.Patient’s participation has become a hot issue in medical care policies and research practices.This article intends to review the research background of patient participation and necessity,status,form,significance and existing problems of total hip replacement patients'participation in health care in order to provide reference for the promotion participation in practice.

Comparison of DAA and PLA Approaches for Total Hip Replacement in the Treatment of Femoral Neck Fractures

Objectives: Femoral neck fractures are becoming more common within nowadays. This research is to explore the clinical effect of primary total hip replacement (THA) via direct anterior approach (DAA) and posterolateral approach (PLA) in the treatment of femoral neck fracture. Methods: Retrospective analysis of 100 cases of elderly patients with femoral neck fracture who underwent total hip arthroplasty admitted to Tianyou Hospital affiliated to Wuhan University of Science and Technology from January 2019 to January 2022. 50 patients treated with DAA approach were included in the observation group, and 50 patients treated with PLA approach were included in the control group. The operation indexes, postoperative acetabular abduction angle and anteversion angle, hip joint function, Harris score and complications were compared between the two groups. Result: The length of incision in the observation group was shorter than that in the control group, and the amount of intraoperative bleeding and postoperative hospital stay were shorter than those in the control group (P < 0.05);There was a statistically significant difference between the two groups in the ratio of acetabular abduction angle and its safe zone, and the length difference of both lower limbs (P < 0.05), while there was no statistically significant difference between the two groups in the ratio of acetabular anteversion angle and its safe zone, eccentricity, and its recovery rate (P > 0.05);Harris score of hip joint: 6 months after operation, the anterior approach group was significantly higher than the posterolateral approach group (P < 0.05), and there was no statistical difference between the two groups 12 months after operation (P > 0.05);The total incidence of complications in the observation group was lower than that in the control group, with a statistically significant difference (P Conclusion: DAA and PLA approaches for total hip replacement can restore the hip joint structure of patients with femoral neck fractures and achieve good results, but DAA approach has greater advantages in early postoperative recovery, improvement of hip joint function, small surgical injury, high application value, so it is recommended.

Hip Tuberculosis at Stage IV: Outcomes and Some Conditions for Total Hip Replacement

Background: Treatment of hip disorders during active hip tuberculosis has long been a controversial issue. Some authors have reported performing hip replacement with different strategies with very good outcomes. This study aimed to describe the surgical outcomes and necessary conditions for total hip replacement in active hip tuberculosis. Methods: We conducted a quasi-experimental study. The study enrolled 40 patients with 42 active tuberculosis hips at stage IV treated by total hip replacement from October 2016 to December 2019 at the National Lung Hospital. We followed up with the patients for at least 12 months, evaluated surgical outcomes, and investigated the factors associated with these outcomes by logistic regression analysis. Results: Surgical outcomes showed that 37 patients (88.1%) had excellent hip function, no abscesses, and no sinus tract formation. Four cases (9.5%) had sinus tract formations. One case (2.4%) had good hip function. Binary logistic regression models revealed that sinus tract formation was associated with preoperative tuberculosis infection syndrome. The average time to obtain antituberculosis drug treatment preoperatively was 4.6 weeks. Conclusion: Total hip replacement for active hip tuberculosis is a practical and promising treatment method. Surgeons should consider improving patients’ conditions before performing total hip replacement, administering antitubercular drugs, and arthrotomy to eliminate all abscesses, and decrease the risk of tuberculosis infection syndrome and the inflammatory response.

Which approach of total hip arthroplasty is the best efficacy and least complication?

BACKGROUND Total hip arthroplasty is as an effective intervention to relieve pain and improve hip function.Approaches of the hip have been exhaustively explored about pros and cons.The efficacy and the complications of hip approaches remains inconclusive.This study conducted an umbrella review to systematically appraise previous meta-analysis(MAs)including conventional posterior approach(PA),and minimally invasive surgeries as the lateral approach(LA),direct anterior approach(DAA),2-incisions method,mini-lateral approach and the newest technique direct superior approach(DSA)or supercapsular percutaneouslyassisted total hip(SuperPath).AIM To compare the efficacy and complications of hip approaches that have been published in all MAs and randomized controlled trials(RCTs).METHODS MAs were identified from MEDLINE and Scopus from inception until 2023.RCTs were then updated from the latest MA to September 2023.This study included studies which compared hip approaches and reported at least one outcome such as Harris Hip Score(HHS),dislocation,intra-operative fracture,wound compliData were independently selected,extracted and assessed by two reviewers.Network MA and cluster rank and surface under the cumulative ranking curve(SUCRA)were estimated for treatment efficacy and safety.RESULTS Finally,twenty-eight MAs(40 RCTs),and 13 RCTs were retrieved.In total 47 RCTs were included for reanalysis.The results of corrected covered area showed high degree(13.80%).Among 47 RCTs,most of the studies were low risk of bias in part of random process and outcome reporting,while other domains were medium to high risk of bias.DAA significantly provided higher HHS at three months than PA[pooled unstandardized mean difference(USMD):3.49,95%confidence interval(CI):0.98,6.00 with SUCRA:85.9],followed by DSA/SuperPath(USMD:1.57,95%CI:-1.55,4.69 with SUCRA:57.6).All approaches had indifferent dislocation and intraoperative fracture rates.SUCRA comparing early functional outcome and composite complications(dislocation,intra-operative fracture,wound complication,and nerve injury)found DAA was the best approach followed by DSA/SuperPath.CONCLUSION DSA/SuperPath had better earlier functional outcome than PA,but still could not overcome the result of DAA.This technique might be the other preferred option with acceptable complications.

Position of the prosthesis and the incidence of dislocation following total hip replacement

Background Dislocation is the second most common complication of hip replacement surgery, and impact of the prosthesis is believed to be the fundamental reason. The present study employed Solidworks 2003 and MSC-Nastran software to analyze the three dimensional variables in order to investigate how to prevent dislocation following hip replacement surgery. Methods Computed tomography （CT） imaging was used to collect femoral outline data and Solidworks 2003 software was used to construct the cup model with variabilities. Nastran software was used to evaluate dislocation at different prosthesis positions and different geometrical shapes. Three dimensional movement and results from finite element method were analyzed and the values of dislocation resistance index （DRI）, range of motion to impingement （ROM-I）, range of motion to dislocation （ROM-D） and peak resisting moment （PRM） were determined. Computer simulation was used to evaluate the range of motion of the hip joint at different prosthesis positions. Results Finite element analysis showed： （1） Increasing the ratio of head/neck increased the ROM-I values and moderately increased ROM-D and PRM values. Increasing the head size significantly increased PRM and to some extent ROM-I and ROM-D values, which suggested that there would be a greater likelihood of dislocation. （2） Increasing the anteversion angle increased the ROM-I, ROM-D, PRM, energy required for dislocation （ENERGY-D） and DRI values, which would increase the stability of the joint. （3） As the chamber angle was increased, ROM-I, ROM-D, PRM, Energy-D and DRI values were increased, resulting in improved joint stability. Chamber angles exceeding 55° resulted in increases in ROM-I and ROM-D values, but decreases in PRM, Energy-D, and DRI values, which, in turn, increased the likelihood of dislocation. （4） The cup, which was reduced posteriorly, reduced ROM-I values （2.1-5.3-°） and increased the DRI value （0.073）. This suggested that the posterior high side had the effect of 10° anteversion angle. Conclusions Increasing the head/neck ratio increases joint stability. Posterior high side reduced the range of motion of the joint but increased joint stability; Increasing the anteversion angle increases DRI values and thus improve joint stability; Increasing the chamber angle increases DRI values and improves joint stability. However, at angles exceeding 55°, further increases in the chamber angle result in decreased DRI values and reduce the stability of the joint.

Physiologic postoperative presepsin kinetics following primary cementless total hip arthroplasty:A prospective observational study

BACKGROUND Presepsin is an emerging biomarker in the diagnosis of sepsis.In the field of orthopaedics,it could be useful in diagnosing and managing periprosthetic joint infections.AIM To define the normal postoperative presepsin plasmatic curve,in patients undergoing primary cementless total hip arthroplasty(THA).METHODS Patients undergoing primary cementless THA at our Institute were recruited.Inclusion criteria were:Primary osteoarthritis of the hip;urinary catheter time of permanence<24 h;peripheral venous cannulation time of permanence<24 h;no postoperative homologous blood transfusion administration and hospital stay≤8 d.Exclusion criteria were:The presence of other articular prosthetic replacement or bone fixation devices;chronic inflammatory diseases;chronic kidney diseases;history of recurrent infections or malignant neoplasms;previous surgery in the preceding 12 mo;diabetes mellitus;immunosuppressive drug or corticosteroid assumption.All the patients received the same antibiotic prophylaxis.All the THA were performed by the same surgical and anaesthesia team;total operative time was defined as the time taken from skin incision to completion of skin closure.At enrollment,anthropometric data,smocking status,osteoarthritis stage according to Kellgren and Lawrence,Harris Hip Score,drugs assumption and comorbidities were recorded.All the patients underwent serial blood tests,including complete blood count,presepsin(PS)and C-reactive protein 24 h before arthroplasty and at 24,48,72 and 96 h postoperatively and at 3,6 and 12-mo follow-up.RESULTS A total of 96 patients(51 female;45 male;mean age=65.74±5.58)were recruited.The mean PS values were:137.54 pg/mL at baseline,192.08 pg/mL at 24 h post-op;254.85 pg/mL at 48 h post-op;259 pg/mL at 72 h post-op;248.6 pg/mL at 96-h post-op;140.52 pg/mL at 3-mo follow-up;135.55 pg/mL at 6-mo follow-up and 130.11 pg/mL at 12-mo follow-up.In two patients(2.08%)a soft-tissue infection was observed;in these patients,higher levels(>350 pg/mL)were recorded at 3-mo follow-up.CONCLUSION The dosage of plasmatic PS concentration is highly recommended in patients undergoing THA before surgery to exclude the presence of an unknown infection.The PS plasmatic concentration should be also assessed at 72 h postoperatively,evaluate the maximum postoperative PS value,and at 96 h post-operatively when a decrease of presepsin should be found.The lack of a presepsin decrease at 96 h post-operatively could be a predictive factor of infection.

Roles of combined femoral and acetabular anteversion in pathological changes of hip dysplasia and hip reconstructive surgery

Combined femoral and acetabular anteversion is the sum of femoral and acetabular anteversion,representing their morphological relationship in the axial plane.Along with the increasing understanding of hip dysplasia in recent years,numerous scholars have confirmed the role of combined femoral and acetabular anteversion in the pathological changes of hip dysplasia.At present,the reconstructive surgery for hip dysplasia includes total hip replacement and redirectional hip preservation surgery.As an important surgery index,combined femoral and acetabular anteversion have a crucial role in these surgeries.Herein,we discuss the role of combined femoral and acetabular anteversion in pathological changes of hip dysplasia,total hip replacement,and redirectional hip preservation surgery.

Preoperative and postoperative risk factors for periprosthetic joint infection in primary total hip arthroplasty:A 1-year experience

BACKGROUND Periprosthetic joint infection(PJI)in primary total hip replacement(THR)is one of the most important threats in orthopedic surgery,so one important surgeon’s target is to avoid or early diagnose a PJI.Although the incidence of PJI is very low(0.69%)in our department,with an average follow-up of 595 d,this infection poses a serious threat due to the difficulties of treatment and the lower functional outcomes after healing.AIM To study the incidence of PJI in all operations occurring in the year 2016 in our department to look for predictive signs of potential infection.METHODS We counted 583 THR for 578 patients and observed only 4 cases of infection(0.69%)with a mean follow-up of 596 d(min 30,max 1451).We reviewed all medical records to collect the data:duration and time of the surgery,presence,type and duration of the antibiotic therapy,preoperative diagnosis,blood values before and after surgery,transfusions,presence of preoperative drugs(in particularly anticoagulants and antiaggregant,corticosteroids and immunosuppressants),presence of some comorbidities(high body mass index,blood hypertension,chronic obstructive pulmonary disease,cardiac ischemia,diabetes,rheumatological conditions,previous local infections).RESULTS No preoperative,intraoperative,or postoperative analysis showed a higher incidence of PJI.We did not find any class with evident major odds of PJI.In our study,we did not find any border value to predict PJI and all patients had similar values in both groups(non-PJI and PJI).Only some categories,such as female patients,showed more frequency of PJI,but this difference related to sex was not statistically significant.CONCLUSION We did not find any category with a higher risk of PJI in THR,probably due to the lack of few cases of infection.

Effectiveness of the Suprainguinal Ultrasound-Guided Block for the Management of Postoperative Pain after Application of a Total Hip Prosthesis

Objective: To assess the effectiveness of ultrasound-guided supraginguinal block (SIB) in the management of pain after total hip replacement. Material and Methods: This was a prospective, randomized, single-blind controlled study carried out in the anesthesia-intensive care unit of the Donka National Hospital in Conakry, over a period of 06 months (01/01/2020 to 30/06/2020). It concerned 32 patients: 16 patients in the “ultrasound-guided SIB” group and 16 patients in the “standard analgesia” group. Results: The pain scores assessed by the simple verbal scale and collected at the different time intervals (6H, 12H, 24H, 36H, 48H) showed mean scores < 1 in the ultrasound-guided SIB group while the mean scores were ≤3 in the standard analgesia group (P < 0.001). On movement, the mean pain scores were ≤1 for the ultrasound-guided SIB group versus mean scores > 3 in the standard analgesia group (P < 0.001). The time to mobilization was greater than 48 hours in all patients in the standard analgesia group while it was less than 48 hours in the majority of patients (75%) in the ultrasound-guided SIB group. Nausea and vomiting were the most observed side effects. We did not observe any respiratory distress. The length of day hospitalization of patients in the ultrasound-guided SIB group was on average 5.50 ± 0.52 compared with 13.44 ± 1.55 in the group of standard analgesia patients (P = 0.001). The vast majority of patients in the ultrasound-guided SIB group were satisfied and unhappy in the standard analgesia group. Conclusion: Our study demonstrated that echo-guided SIB provided better analgesia compared to standard analgesia for the management of postoperative pain after total hip replacement.

ANALYSIS AND RESEARCH OF COMPUTER-AIDED MODEL OF HIP JOINT BASED ON REVERSE ENGINEERING

Former research work about the modeling of hip joint focus on the uppersegment of femoral, and assumes the acetabulum cup is sphere concave, and the acetabulum prosthesesis semisphere. A method of acquiring the point data on the surface of the hipbone using the reverseengineering technology is presented. After analyzing the acetabulum surface fitting error, arotation ellipsoid CAD model is applied to fit the acetabulum surface, and then optimizationtechnique is used to find the geometric parameters of the model. The fitting error between thesphere and rotation ellipsoid is compared and gets the result that the fitting error of rotationellipsoid is smaller than sphere, and the rotation ellipsoid can describe the shape of theacetabulum better.

Use of short stems in revision of standard femoral stem:A case report

BACKGROUND Short stems are usually uncemented prosthetics and are recommended in the treatment of traumatic or degenerative diseases of hip.In revision procedures for elderly patients with serious comorbidity,applying a short stem could reduce peri-and post-operative secondary surgical risks to femoral osteotomy,which are necessary for the removal of parts of the implant or acrylic cement from the medullary canal.There are no cases in the literature that apply a short stem for prosthetic revision by acrylic cement anchorage.CASE SUMMARY A male patient had a left hip replacement in 1995 due to coxarthrosis.At the age of eighty the patient reported an accidental trauma and walked with pain in the left thigh.The X-ray highlighted the stem breakage in the distal section without fracturing the femoral cortex.The patient had various comorbidities(diabetes,anaemia,heart deficiency,and arrhythmia)presenting a high operation risk(ASA 4).During the revision procedure,the distal apex of the stem could not be removed from the femoral cortex.Because of the poor general health of the patient,the surgeon decided not to perform a Wagner femoral osteotomy to remove the distal section of the stem and decided to implant a short stem to avoid removing the stem section of the previous implant.The patient had his left femur X-rayed 15 d post-trauma.CONCLUSION A field of application of short stem may be the development of a cemented short stem to reduce the complexity of the revision procedure.

Observational study of a new modular femoral revision system

BACKGROUND The uncemented ArcosTM Modular Femoral Revision System(ARCOS)is a new comprehensive,press-fit revision design.The modular design offers a wide range of possible combinations to accommodate different variations of anatomy and bone stock.The ARCOS is made by a proximal body and a distal stem.As probably the only ones worldwide we predominantly use a combination of body and stem which supports proximal fixation and load,since this mimics the concept of the primary total hip arthroplasty with proximal weight-bearing,leading to bone stock preservation and no stress shielding or thigh pain.AIM To evaluate the early results after femoral revision in a consecutive series of patients undergoing surgery over 3 years.METHODS We included 116 patients in the study.They were operated in the period August 2011 to December 2014 and we got a clinical mean observation time of 4(0.5-6)years.Clinical and radiographical follow-up included present function of the hip assessed by Harris Hip Score,Oxford Hip Score,and EQ5D(measure of health outcome).Of the 116 patients,17 died in the interim and were consequently included only in the implant survivorship analysis;46 patients attended the follow-up control.RESULTS In total 6(5%)hips were re-revised due to infection(n=3),fracture(n=2)or subsidence(n=1).No patient was re-revised due to aseptic loosening.The 1-,2-and 5-year probability of implant survival(95%CI)were 97%(93%-100%),97%(93%-100%)and 96%(92%-99%),respectively.In this cohort 95 patients received a combination of a proximal broach and a distal curved and slotted stem(BS),aiming for proximal fixation and load bearing;21 patients received a different combination.When comparing these two groups the BS-group had a 5-year implant survival probability(95%CI)of 97%(93%-100%)compared with the group of other combinations with a 5-year implant survival probability(95%CI)of 90%(78%-100%)(P=0.3).Our regression analysis showed that periprosthetic fracture as an indication for the ARCOS operation was the only significant negative outcome predictor.The mean Harris Hip Score result(100 points being best)was 83(range 5-98).The mean Oxford Hip Score result(48 points being best)was 40(range 19-48).CONCLUSION The early results of the ARCOS are promising compared with similar studies.We encourage the use of the BS combination whenever the bone stock proximally is adequate.

A preliminary experimental investigation on the biotribocorrosion of a metal-on-polyethylene hip prosthesis in a hip simulator

Corrosion at the taper/trunnion interface of total hip replacement(THR)often results in severe complications.However,the underlying mechanisms of biotribocorrosion at the taper/trunnion interface during the long-term walking gait cycles remain to be fully understood.In this study,a hip joint simulator was therefore instrumented with an electrochemical cell for in-situ monitoring of the tribocorrosion evolution in a metal-on-polyethylene(MoP)THR during a typical long-term walking gait.In addition,the biotribocorrosion mechanism was investigated via surface and chemical characterizations.The experimental results confirmed that the taper/trunnion interface dominated the contemporary MoP hip joint corrosion.Three cyclic variations in the open circuit potential(OCP)were observed throughout the long-term electrochemical measurements,attributed to the formation and disruption of the adsorbed protein layer.The corrosion exhibited an initial increase at each period,peaking at approximately 0.125 million cycles,followed by a subsequent gradual reduction.Surface and chemical analyses revealed the formation of a tribochemical reaction layer(tribolayer)on the worn surface of the taper/trunnion interface.The surface/chemical characterizations and the electrochemical measurements indicated that the adhesion force of the adsorbed protein layer was weaker than that of the tribolayer.In contrast,the opposite was true for the corrosion resistance.Based on the observations from this study,the tribocorrosion mechanism of the taper/trunnion interface under the long-term walking gait cycles is deduced.