Investigation of contact behavior on a model of the dual-mobility artificial hip joint for Asians in different inner liner thicknesses

BACKGROUND The four components that make up the current dual-mobility artificial hip joint design are the femoral head,the inner liner,the outer liner as a metal cover to prevent wear,and the acetabular cup.The acetabular cup and the outer liner were constructed of 316L stainless steel.At the same time,the inner liner was made of ultra-high-molecular-weight polyethylene(UHMWPE).As this new dual-mobility artificial hip joint has not been researched extensively,more tribological research is needed to predict wear.The thickness of the inner liner is a significant component to consider when calculating the contact pressure.AIM To make use of finite element analysis to gain a better understanding of the contact behavior in various inner liner thicknesses on a new model of a dual-mobility artificial hip joint,with the ultimate objective of determining the inner liner thickness that was most suitable for this particular type of dual-mobility artificial hip joint.METHODS In this study,the size of the femoral head was compared between two diameters(28 mm and 36 mm)and eight inner liner thicknesses ranging from 5 mm to 12 mm.Using the finite element method,the contact parameters,including the maximum contact pressure and contact area,have been evaluated in light of the Hertzian contact theory.The simulation was performed statically with dissipated energy and asymmetric behavior.The types of interaction were surface-to-surface contact and normal contact behavior.RESULTS The maximum contact pressures in the inner liner(UHMWPE)at a head diameter of 28 mm and 36 mm are between 3.7-13.5 MPa and 2.7-10.4 MPa,respectively.The maximum von Mises of the inner liner,outer liner,and acetabular cup are 2.4–11.4 MPa,15.7–44.3 MPa,and 3.7–12.6 MPa,respectively,for 28 mm head.Then the maximum von Mises stresses of the 36 mm head are 1.9-8.9 MPa for the inner liner,9.9-32.8 MPa for the outer liner,and 2.6-9.9 MPa for the acetabular cup.A head with a diameter of 28 mm should have an inner liner with a thickness of 12 mm.Whereas the head diameter was 36 mm,an inner liner thickness of 8 mm was suitable.CONCLUSION The contact pressures and von Mises stresses generated during this research can potentially be exploited in estimating the wear of dual-mobility artificial hip joints in general.Contact pressure and von Mises stress reduce with an increasing head diameter and inner liner’s thickness.Present findings would become one of the references for orthopedic surgery for choosing suitable bearing geometric parameter of hip implant.

Two-stage revision arthroplasty for coagulase-negative staphylococcal periprosthetic joint infection of the hip and knee

BACKGROUND Periprosthetic joint infections(PJIs)are frequently caused by coagulase-negative Staphylococci(CoNS),which is known to be a hard-to-treat microorganism.Antibiotic resistance among causative pathogens of PJI is increasing.Two-stage revision is the favoured treatment for chronic CoNS infection of a hip or knee prosthesis.We hypothesised that the infection eradication rate of our treatment protocol for two-stage revision surgery for CoNS PJI of the hip and knee would be comparable to eradication rates described in the literature.AIM To evaluate the infection eradication rate of two-stage revision arthroplasty for PJI caused by CoNS.METHODS All patients treated with two-stage revision of a hip or knee prosthesis were retrospectively included.Patients with CoNS infection were included in the study,including polymicrobial cases.Primary outcome was infection eradication at final follow-up.RESULTS Forty-four patients were included in the study.Twenty-nine patients were treated for PJI of the hip and fifteen for PJI of the knee.At final follow-up after a mean of 37 mo,recurrent or persistent infection was present in eleven patients.CONCLUSION PJI with CoNS can be a difficult to treat infection due to increasing antibiotic resistance.Infection eradication rate of 70%-80%may be achieved.

Cemented versus uncemented stems for revision total hip replacement:A systematic review and meta-analysis

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.

Two-stage revision in periprosthetic knee joint infections

Periprosthetic joint infection(PJI)following total knee arthroplasty is one of the most catastrophic and costly complications that carries significant patient wellness as well as economic burdens.The road to efficiently diagnosing and treating PJI is challenging,as there is still no gold standard method to reach the diagnosis as early as desired.There are also international controversies with respect to the best approach to manage PJI cases.In this review,we highlight recent advances in managing PJI following knee arthroplasty surgery and discuss in depth the two-stage revision method.

Jumbo cup in hip joint renovation may cause the center of rotation to increase

BACKGROUND Utilizing the large jumbo cup in revision total hip arthroplasty is an effective approach to cure many lacunar and segmental peripheral bone defects.However,with the use of the jumbo cup,the center of the hip joint may become elevated relative to the primary acetabulum,and the diameter of the large cup is greater.AIM To study the height and the significance of the elevation of the hip joint center.METHODS Eighty-eight patients matched the criteria for this condition and were included in the study.The center height of the hip joint was measured relative to the opposite normal hip joint.The diameter of the jumbo cup was measured and checked according to operation notes,and the diameter of the jumbo cup was measured with a prosthesis label.Then,the horizontal and vertical centers of rotation were measured on the surgical side and opposite side.The average center height of the hip joint on the renovated side and the opposite side and the position of the hip cup relative to the teardrop were compared using a paired t-test.RESULTS Radiometric analysis showed that the average hip joint center was elevated by 7.6 mm.The rotational center height delta of the renovated hip was 7.6±5.6 mm,and there was an obvious difference between the two groups(P=0.00).The difference in horizontal distance was 0.5±5.1 mm(-11.5-14.0 mm),and there was no obvious difference between the two groups(P=0.38).According to the foreign standard,the rotational center height delta of the renovated hip was 7.5±6.2 mm,and there was a significant difference between the two groups(P=0.00).There was no obvious difference between the domestic and foreign standards(P>0.05)between the two groups.CONCLUSION The application of the jumbo cup elevates the rotational center of the hip joint,but it is feasible and effective to use the jumbo cup.

Can periprosthetic hip joint infections be successfully managed by debridement and prosthesis retention?

To evaluate the current literature about how successfully periprosthetic hip joint infections can be managed by debridement and prosthesis retention.A literature search was performed through Pub Med until September 2013.Search terms were"DAIR(debridement,antibiotics,irrigation,and retention)"alone and in combination with"hip"as well as"hip infection+prosthesis retention".A total of 11 studies reporting on 292 cases could be identified.Five different treatment modalities have been described with varying success rates(debridement-21%infection eradication rate;debridement+lavage-75%infection eradication rate;debridement,lavage,with change of modular prosthesis components-70.4%infection eradication rate;debridement,lavage,change of modular prosthesis components+vacuum-assisted closure-92.8%infection eradication rate;acetabular cup removal+spacer head onto retained stem-89.6%infection eradication rate).With regard to the postoperative antibiotic therapy,no general consensus could be drawn from the available data.Debridement,antibiotic therapy,irrigation,and prosthesis retention is an acceptable solution in the management of early and acute hematogenous periprosthetic hip joint infections.The current literature does not allow for generalization of conclusions with regard to thebest treatment modality.A large,multi-center study is required for identification of the optimal treatment of these infections.

Management of Severe Femoral Bone Defect in Revision Total Hip Arthroplasty-A 236 Hip,6-14-year Follow-up Study

Summary： This study evaluated the clinical effect of impaction bone graft and distal press-fit fixation for the reconstruction of severe femoral bone defect in revision total hip arthroplasty. A total of 234 patients （involving 236 hips） with Paprosky III and 1V femoral bone defects were treated with the revision total hip arthroplasty from June 1998 to Aug. 2006. Impaction bone graft technique was used for 112 hips, with allogeneic freeze-dried bone as bone graft and SP II as prosthesis. With 124 hips, modular distal press-fit fixation and tapered femoral stem （MP stem） were employed. After the operation, the subjects were followed up on regular basis and results were assessed by using the Harris Hip Score （HHS） and 12-item Short Form Health Survey （SF-12）. Radiolucence, subsidence and loosening were observed and complications, including infection, fracture, dislocation etc. were recorded. A 6-14-year follow-up showed that prostheses failed, due to infection, in 4 patients of impaction bone graft group and that 6 patients in the press-fit fixation group experienced prosthesis failure, with the survival rates for the two techniques being 96.43% and 95.16%, respectively. One-way ANOVA showed that prosthesis survival was significantly associated with surgery-related complications （P〈0.05） and was not related to the type of the bone defects （P〉0.05）. The rate of complications bore significant association with the type of bone defects in the two groups （P〈0.05）. Our study showed that the two revision methods could achieve satisfactory mid-term and long-term results for the reconstruction of severe bone defects. It is of great significance for attaining high prosthesis survival rate to select suitable operation on the basis of the type of bone defect. Careful operative manipulation and post-operative rehabilitation aimed at reducing complications are also important.

A Biomimetic Hip Joint Simulator and its Application in in vitro Study of the Integrity of Replacement Cemented Hip

A biomimetic hip joint simulator that can be used to evaluate the outcome of the cemented total hip replacement has been designed, manufactured and evaluated. The simulator produces motion in the extension/flexion plane, with a socket to rotate internal/externally. At the same time a dynamic loading cycle is applied. A validation test was performed on a cemented femoral stem within a novel composite femur. The hone quality has a strong effect on the stem migration and on the integrity of the interfaces. The migration of the stem is a combination of 3-D translation and rotation of the stem. Under the same loading conditions, weak bone allows more stem migration than strong bone. There is a great decrease in the strength of the stem-cement interface after the dynamic test, and the weak bone composite exhibited a greater reduction in interfacial strength than the strong bone composite. The decrease of the interfacial strength indicates that the primary bonding between the stem and the cement mantle had deteriorated and the integrity of stem-cement interface was damaged. The study demonstrates the value of using a hip joint simulator to investigate stem migration and interface integrity within the cemented hip replacement, suggesting that method can be used for in vitro evaluation of the biomaterials used in the cemented hip replacements.

3D Printing Hip Prostheses Offer Accurate Reconstruction,Stable Fixation,and Functional Recovery for Revision Total Hip Arthroplasty with Complex Acetabular Bone Defect

Complicated and large acetabular bone defects present the main challenges and difficulty in the revision of total hip arthroplasty(THA).This study aimed to explore the advantages of three-dimensional(3D)printing technology in the reconstruction of such acetabular bone defects.We retrospectively analyzed the prognosis of four severe bone defects around the acetabulum in three patients who were treated using 3D printing technology.Reconstruction of bone defect by conventional methods was difficult in these patients.In this endeavor,we used radiographic methods,related computer software such as Materialise's interactive medical image control system and Siemens NX software,and actual surgical experience to estimate defect volume,prosthesis stability,and installation accuracy,respectively.Moreover,a Harris hip score was obtained to evaluate limb function.It was found that bone defects could be adequately reconstructed using a 3D printing prosthesis,and its stability was reliable.The Harris hip score indicated a very good functional recovery in all three patients.In conclusion,3D printing technology had a good therapeutic effect on both complex and large bone defects in the revision of THA.It was able to achieve good curative effects in patients with large bone defects.

Conversion total hip arthroplasty: Primary or revision total hip arthroplasty

Total hip arthroplasty(THA) is an increasingly common procedure among elderly individuals.Although conversion THA is currently bundled in a diagnosis related group(DRG) with primary THA,there is a lack of literature supporting this classification and it has yet to be identified whether conversion THA better resembles primary or revision THA.This editorial analyzed the intraoperative and postoperative factors and functional outcomes following conversion THA,primary THA,and revision THA to understand whether the characteristics of conversion THA resemble one procedure or the other,or are possibly somewhere in between.The analysis revealed that conversion THA requires more resources both intraoperatively and postoperatively than primary THA.Furthermore,patients undergoing conversion THA present with poorer functional outcomes in the long run.Patients undergoing conversion THA better resemble revision THA patients than primary THA patients.As such,patients undergoing conversion THA should not be likened to patients undergoing primary THA when determining risk stratification and reimbursement rates.Conversion THA procedures should be planned accordingly with proper anticipation of the greater needs both in the operating room,and for in-patient and followup care.We suggest that conversion THA be reclassified in the same DRG with revision THA as opposed to primary THA as a step towards better allocation of healthcare resources for conversion hip arthroplasties.

Chromium Content in the Human Hip Joint Tissues

Objective Chromium has many important functions in the human body. For the osseous tissue, its role has not been clearly defined. This study was aimed at determining chromium content in hip joint tissues. Methods A total of 91 hip joint samples were taken in this study, including 66 from females and 25 from males. The sample tissues were separated according to their anatomical parts. The chromium content was determined by the AAS method. The statistical analysis was performed with U Mann-Whitney＇s non-parametric test, P〈0.05. Results The overall chromium content in tissues of the hip joint in the study subjects was as follows： 5.73 μg/g in the articular cartilage, 5.33 μ/g in the cortical bone, 27.86 μ/g in the cancellous bone, 5.95 μg/8 in the fragment of the cancellous bone from the intertrochanteric region, and 2.28 μ/g in the joint capsule. The chromium contents were observed in 2 group patients, it was 7.04 μ/g in people with osteoarthritis and 22.59 μ/g in people with fractures. Conclusion The observed chromium content was highest in the cancellous bone and the lowest in the joint capsule. Chromium content was significantly different between the people with hip joint osteoarthritis and the people with femoral neck fractures.

Total hip revision with custom-made spacer and prosthesis:A case report

BACKGROUND Both periprosthetic joint infections(PJIs)and severe femoral segmental defects are catastrophic complications of total hip arthroplasty(THA),and both present a significant challenge in revisional surgery.There are limited data available to guide clinical decision making when both occur concurrently.CASE SUMMARY A 61-year-old woman presented with a 6-mo history of a sinus tract at the site of her original THA incision.Radiological imaging revealed a total hip joint implant with an ipsilateral segmental femoral defect.Based on histological,radiological,laboratory,and clinical features,a diagnosis of concurrent chronic PJI and segmental femoral defect(Type IIIB,Paprosky classification)was made.After multidisciplinary team discussion,three-dimensional(3D)-printed,custom-made antibiotic spacers were created that could be used to mold antibiotic-loaded cement spacer.These were placed following PJI debridement in the first stage of revision surgery.After the PJI was eliminated,a 3D-printed,custom-made,femoral prosthesis was created to repair the considerable femoral defect.After 20-mo follow-up,the patient had excellent functional outcomes with a near-normal range of hip movement.So far,neither evidence of recurrent infection nor loosening of the prosthesis has been observed.CONCLUSION We describe a case of“two-stage,custom-made”total hip revision to treat PJI with a concurrent segmental femoral defect.Use of a personalized,3D-printed spacer and proximal femoral prosthesis led to satisfactory hip function and no early postoperative complications.Use of a customized implant provides surgeons with an alternative option for patients where no suitable spacer or implant is available.However,the long-term function,longevity,and cost-effectiveness of the use of custom-made prostheses have yet to be fully explored.

Improved patient reported outcomes with functional articulating spacers in two-stage revision of the infected hip

BACKGROUND Two-stage revision arthroplasty with an antibiotic-loaded spacer is the treatment of choice in chronically infected total hip arthroplasties.Interval spacers can be functional articulating or prefabricated.Functional results of these spacers have scarcely been reported.AIM To compare retrospectively the patient reported outcome and infection eradication rate after two-stage revision arthroplasty of the hip with the use of a functional articulating or prefabricated spacer.METHODS All patients with two-stage revision of a hip prosthesis at our hospital between 2003 and 2016 were included in this retrospective cohort study.Patients were divided into two groups;patients treated with a functional articulating spacer or with a prefabricated spacer.Patients completed the Hip Osteoarthritis Outcome Score and the EQ-5D-3L(EQ-5D)and the EQ-5D quality of life thermometer(EQVAS)scores.Primary outcomes were patient reported outcome and infection eradication after two-stage revision.The results of both groups were compared to the patient acceptable symptom state for primary arthroplasty of the hip.Secondary outcomes were complications during spacer treatment and at final follow-up.Descriptive statistics,mean and range are used to represent the demographics of the patients.For numerical variables,students’t-tests were used to assess the level of significance for differences between the groups,with 95%confidence intervals;for binary outcome,we used Fisher’s exact test.RESULTS We consecutively treated 55 patients with a prefabricated spacer and 15 patients with a functional articulating spacer of the hip.The infection eradication rates for functional articulating and prefabricated spacers were 93%and 78%,respectively(P>0.05).With respect to the functional outcome,the Hip Osteoarthritis Outcome Score(HOOS)and its subscores(all P<0.01),the EQ-5D(P<0.01)and the EQVAS scores(P<0.05)were all significantly better for patients successfully treated with a functional articulating spacer.More patients in the functional articulating spacer group reached the patient acceptable symptom state for the HOOS pain,HOOS quality of life and EQ-VAS.The number of patients with a spacer dislocation was not significantly different for the functional articulating or prefabricated spacer group(P>0.05).However,the number of dislocations per patient experiencing a dislocation was significantly higher for patients with a prefabricated spacer(P<0.01).CONCLUSION Functional articulating spacers lead to improved patient reported functional outcome and less perioperative complications after two-stage revision arthroplasty of an infected total hip prosthesis,while maintaining a similar infection eradication rate compared to prefabricated spacers.

One-stage revision in two cases of Salmonella prosthetic hip infection

We describe two cases of prosthetic joint infection(PJI) of the hip due to Salmonella. The first patient presented with an early infection 5 d after being discharged following a total hip replacement and the second patient presented at the emergency ward with a late infection, thirteen years following a total hip replacement. Both cases occurred within one month of each other at our institution and both were successfully treated with a one-stage revision. PJI caused by Salmonella species is very rare: so far only 20 Salmonella PJIs of the hip have been described. Therefore, full consensus on the best treatment approach has not yet been reached. An aggressive two-stage approach is advised because of the virulence of Salmonella, although a limited number of successful one-stage approaches have been describedas well. According to the latest guidelines, one-stage revision has comparable success rates and less morbidity compared to two-stage treatment, when selecting the right patients. In our opinion, PJI caused by Salmonella should be treated just as PJI caused by other bacteria, with consideration of the selection criteria as mentioned in several treatment guidelines. As illustrated by these two cases, one-stage revision can be successful in both early and late Salmonella PJI of the hip.

“Meniscal” scar as a landmark for the joint line in revision total knee replacement

AIM To determine whether tissue identified at the joint line was actually remnant "meniscal" scar tissue or not. METHODS Nine patients undergoing revision knee surgery following informed consent had meniscal scar tissue sent to the histology department for analyses. All revisions were performed where joint line had been raised or lowered at earlier surgery. Although preoperative radiographic evaluations suggested that the joint line had been altered, intraoperatively there was scar tissue at the level of the recreated joint line. This scar tissue has traditionally been described as meniscal scar, and to identify the origins of this tissue, samples were sent for histological analyses. The tissue samples were stored in formalin, and embedded and sectioned before undergoing histochemical staining. All samples underwent macroscopic and microscopic examination by a histopathologist who was blind to the study aims. The specific features that were examined included tissue organisation, surface and central composition, cellular distribution including histiocytes, nuclear ratio and vasculature. Atypical and malignant features, inflammation and degeneration were specifically looked for. A statistical review of the study was performed by a biomedical statistician.RESULTS The histological findings for the nine patients showingthe macroscopic and microscopic findings, and the conclusion are outlined in a Table. The histological analyses were reviewed to determine whether the tissue samples were likely to be meniscal scar tissue. The response was yes(2, 22%), no(6, 67%) and maybe(1,11%) based on the conclusions. The results were "yes"when on macroscopy, firm cream tissue was identified.In these two "yes" samples, microscopic analyses showed organised fibrous tissue with focal degenerative areas with laminated pattern associated with histiocytes peripherally but no inflammation. The "no" samples were assessed macroscopically and microscopically and were deemed to have appearances representing fibrous synovial tissue and features in keeping with degenerate scar tissue or connective tissue. One sample was indeterminate and microscopically contained fibrocollagenous tissue with synovial hyperplasia. It also contained some degenerate hyalinised tissue that may represent cartilage, but the appearances were not specific. CONCLUSION Based on our pilot study, we recommend reliance on a number of markers to identify the joint line as outlined above, and to exercise caution in using the "meniscal"scar.

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.

The Developmentand Clinical Application of Acoustical Technique in Hip Joint

A non- invasive acoustical system was developed for the measurement of transmission properties of acoustic waves in the hip joints.The instrumentation consisted of three sub- system s. An excitation system employed a vibratory force at the sacrum of the test subjects.A transduction system included a pair of identical microphones installed in the tubes of two stethoscopes,which were placed at the greater trochanters on both sides for picking up the acoustical signals transm it- ted across the hip joints.The data acquisition and analysis system was a portable signal analyzer with a program of dual channel digital filter for m easuring the power of acoustical signal in 1/ 3- oc- tave frequency bands.2 7normal adults,2 0 normal pre- school children and 4 0 norm al neonates were random ly selected for testing.Coherence function (CF) and discrepancy(D) was measured during the testing.Results from the three groups showed that there was a high coherence of the signals (CF>0 .9) and a sm all discrepancy(D<3d B) between bilateral hips in the frequency range of2 0 0— 315 Hz.For normal neonates,there was a wider frequency range of16 0 - 315 Hz in which the acoustical signals m aintained a high coherence (CF>0 .93) and a smaller discrepancy (D <2 d B) was observed.This study showed that the development of the acoustical technique pro- vided a practical m ethod with objective parameters.The results obtained in this study can offer a baseline for further investigation of hip disorders particularly those related to structural abnorm ali- ties of the hip.

Intraoperative Fracture of the Femur in Revision Total Hip Arthroplasty with a Fully HA-Coated Stem

A retrospective review was made of intraoperative femoral fracture prevalence in seventy nine consecutive, cementless, fully HA-coated stems used for revision hip arthroplasty. Three patients were lost to follow up. Intraoperative fracture occurred in 15 (20%) femurs. Fractures occurred during cement removal (3/15) or insertion of the implant (12/15). All fractures were identified using intraoperative biplane X-ray, and were treated during the same operation. The clinical outcome of both groups (with or without fractures) was similar. The risk of intraoperative fracture was not statistically related to any demographic features or operative technique. Intraoperative radiographs are therefore mandatory in revision hip arthroplasty in order to diagnose and treat the common complication of femur fracture appropriately.

Analysis of the clinical efficacy of two-stage revision surgery in the treatment of periprosthetic joint infection in the knee:A retrospective study

BACKGROUND Periprosthetic joint infection(PJI)is a catastrophic complication that can occur following total knee arthroplasty(TKA).Currently,the treatment for PJI mainly includes the use of antibiotics alone,prosthetic debridement lavage,primary revision,secondary revision,joint fusion,amputation,etc.AIM To explore the clinical effect of two-stage revision surgery for the treatment of PJI after TKA.METHODS The clinical data of 27 patients(3 males and 24 females;age range,47–80 years;mean age,66.7±8.0 years;27 knees)with PJI treated with two-stage revision surgery in our hospital between January 1,2010 and December 31,2020 were analyzed retrospectively.The following outcomes were compared for changes between preoperative and last follow-up results:Erythrocyte sedimentation rate(ESR),C-reactive protein(CRP),visual analogue scale(VAS)scores,Hospital for Special Surgery(HSS)scores,knee range of motion(ROM),and infection cure rates.RESULTS All 27 patients were followed up(range,13–112 mo).The ESR(14.5±6.3 mm/h)and CRP(0.6±0.4 mg/dL)of the patients at the last follow-up were significantly lower than those at admission;the difference was statistically significant(P<0.001).The postoperative VAS score(1.1±0.7),HSS score(82.3±7.1),and knee ROM(108.0°±19.7°)were significantly improved compared with those before the surgery;the difference was statistically significant(P<0.001).Of the 27 patients,26 were cured of the infection,whereas 1 case had an infection recurrence;the infection control rate was 96.3%.CONCLUSION Two-stage revision surgery can effectively relieve pain,control infection,and retain good joint function in the treatment of PJI after TKA.

Systematic review of single stage revision for prosthetic joint infection

While advanced technology,increased medical knowledge and improved surgical technique has improved patient outcomes in total joint arthroplasty,prosthetic joint infection still remains one of the leading causes of increased healthcare costs,medical resources and societal burdens in orthopaedic care.Two stage arthroplasty revision remains the gold standard for treatment of prosthetic joint infection.Proponents of single stage revision arthroplasty for infection argue that it results in lower healthcare costs while improving patient reported functional outcomes and with equivalent success rates.Here we review the history of single stage revision arthroplasty,discuss the key principles,highlight the indications and contraindications,and review the reported outcomes with a focus on future developments of single stage revision arthroplasty for hip and knee periprosthetic joint infections.