The median effective concentration of ropivacaine for ultrasound-guided anterior iliopsoas muscle space block in the elderly undergoing hip surgery: a dose-finding study.

Background: In order to improve perioperative pain and reduce the adverse outcome of severe pain in elderly hip fractures, anterior iliopsoas muscle space block (AIMSB) can be used clinically to reduce pain. The aim of the study is to investigate the 50% effective concentration (EC50) of ropivacaine for ultrasound-guided anterior iliopsoas space block in elderly with hip fracture. Methods: A total of 27 patients were enrolled with aged ≥65 years, American society of Anesthesiologists (ASA) physical status classification II-III and undergoing Total Hip Arthroplasty (THA). We measured the EC50 using Dixon's up-and-down method. Ultrasound-guided AIMSB was performed preoperatively with an initial concentration of 0.2% in the first patient. After a successful or unsuccessful postoperative analgesia, the concentration of local anesthetic was decreased or increased 0.05%, respectively in the next patient. The successful block effect was defined as no sensation to pinprick in the area with femoral nerve, obturator nerve, and lateral femoral cutaneous nerve in 30 min. Meanwhile, the EC50 of ropivacaine was determined by using linear model, linear-logarithmic model, probit regression model, and centered isotonic regression. Results: A total of 12 patients (48%) had a successful block. All patients with a successful block had a postoperative visual analog scale score of <4 in the 12 h. The estimated EC50 values in linear model, linear-logarithmic model, probit regression model, and centered isotonic regression (a nonparametric method) were 0.268%, 0.259%, 0.277%, and 0.289%. The residual standard error of linear model was the smallest (0.1245). Conclusion: The EC50 of ropivacaine in anterior iliopsoas space block under ultrasound guidance is 0.259-0.289%.

[Radiographic measurements of acetabular component orientation with Widmer´s method in total hip arthroplasty. Descriptive case series]. / Mediciones radiográficas de la orientación del componente acetabular con el método de Widmer en la artroplastía total de cadera. Serie de casos descriptiva.

INTRODUCTION: total hip arthroplasty (THA) is one of the most performed surgeries worldwide, with high satisfaction rates. The orientation of the acetabular component has a direct impact on the risk of dislocation, recently with the support of robotic surgery the margin of error in implant placement has decreased; however, the conventional technique even without fluoroscopic support continues to have satisfactory results within the safety zone. MATERIAL AND METHODS: retrospective, cross-sectional, descriptive case series of patients treated with THA at Hospital General Xoco between 2022 and 2024. Degrees of anteversion and inclination were measured with Widmer's method on postoperative radiographs. RESULTS: the radiographs of 113 patients were studied, 80 female and 33 male, with a mean age of 63.2 ± 13.01 years (95% CI: 60.6-65.4), a mean inclination of 42.2° ± 8.1° (95% CI: 40.7-43.2) and anteversion of 14.3° ± 8.5° (95% CI: 12.5-15.4); 76% of the population was within Lewinnek safe zone; by etiology: osteoarthrosis 74%, sequelae of dysplasia 68% and intracapsular fracture 82%; difference between the values of the affected side: left 65%, right 83%, of 3.9° and 4.7°/6.4o and 9° in relation to the overall values of the population. CONCLUSION: in our population undergoing THA, without the use of robotic technique or support of imaging studies, anteversion and inclination figures were recorded within the Lewinnek safety parameters with a conventional method.

INTRODUCCIÓN: la artroplastía total de cadera (ATC) es una de las cirugías más realizadas a nivel mundial, con altos porcentajes de satisfacción. La orientación del componente acetabular tiene impacto directo en el riesgo de luxación; recientemente, con el apoyo de la cirugía robótica, el margen de error en la colocación de los implantes ha disminuido; sin embargo, la técnica convencional, incluso sin apoyo fluoroscópico, continúa teniendo resultados satisfactorios dentro de la zona de seguridad. MATERIAL Y MÉTODOS: serie de casos retrospectiva, transversal y descriptiva, de pacientes tratados con ATC en Hospital General Xoco entre 2022 y 2024. Se midieron los grados de anteversión e inclinación con el método de Widmer en las radiografías postoperatorias. RESULTADOS: se estudiaron las radiografías de 113 pacientes, 80 mujeres y 33 hombres, con edad media de 63.2 ± 13.01 años (IC95%: 60.6-65.4), se obtuvo una inclinación media de 42.2° ± 8.1° (IC95%: 40.7-43.2) y anteversión de 14.3° ± 8.5° (IC95% 12.5-15.4); 76% de la población se encontraba dentro de la zona segura de Lewinnek; por etiología: osteoartrosis 74%, secuelas de displasia 68% y fractura intracapsular 82%; diferencia entre los valores del lado afectado: izquierdo 65%, derecho 83%, de 3.9° y 4.7°/6.4° y 9° en relación con los valores globales de la población. CONCLUSIÓN: en nuestra población sometida a ATC, sin uso de técnica robótica o apoyo de estudios de imagen, se registraron cifras de anteversión e inclinación dentro de los parámetros de seguridad de Lewinnek con un método convencional.

[Total hip arthroplasty with supracondylar shortening osteotomy in Crowe 4 inveterate hip dislocation: case report and surgical technique]. / Artroplastía total de cadera con osteotomía de acortamiento supracondílea en luxación inveterada de cadera Crowe 4: caso clínico y técnica quirúrgica.

Structural deformities of the acetabulum secondary to developmental dysplasia of the hip (DDH) are one of the most common causes requiring total hip arthroplasty (THA), whether in conjunction with femoral osteotomy in cases of Crowe dislocation 4. Several techniques have been described, studied, and compared, but there is no superiority of one technique over another. Currently, most hip surgeons perform a subtrochanteric osteotomy. With a follow-up of 10 years, good results have been obtained, so there is a need to present a therapeutic alternative with potential benefits, mainly in restoring the center of rotation of the hip, preserving the proximal bone component, and reducing complications. Therefore, this study aims to describe the surgical technique of CTA in conjunction with supracondylar shortening osteotomy in a 29-year-old female patient, using an uncemented acetabular cup, a short uncemented stem with ceramic-polyethylene bearing, and distal fixation with a 4-hole plate LC-LCP, with the goal of restoring the natural biomechanics of the hip.

Las deformidades estructurales del acetábulo como secuelas de displasia en el desarrollo de la cadera es una de las patologías más frecuentes que ameritan como tratamiento la cirugía de artroplastía total de cadera (ATC) asociada o no a osteotomía femoral en casos de luxación inveterada clasificada como Crowe 4. Múltiples técnicas han sido descritas, estudiadas y comparadas; sin embargo, no existe superioridad de una sobre otra. Actualmente, la osteotomía realizada por la mayoría de los cirujanos de cadera es subtrocantérica, se han reportado buenos resultados a 10 años de seguimiento. La necesidad de presentar una alternativa terapéutica con posibles beneficios, principalmente en la restitución del centro de rotación de la cadera, preservación de componente óseo proximal y disminución de las complicaciones, es meritoria en el campo quirúrgico. Por lo tanto, este estudio se propone describir la técnica quirúrgica de ATC asociada a osteotomía de acortamiento supracondílea en un paciente femenino de 29 años, con uso de copa acetabular no cementada, vástago corto no cementado con par de fricción cerámica-polietileno y fijación distal con placa LC-LCP de cuatro orificios, con el objetivo de restaurar la biomecánica natural de la cadera.

A comparison of the clinical efficacy of total hip arthroplasty via direct anterior approach and posterior approach: A meta-analysis.

BACKGROUND: The approach of total hip arthroplasty (THA) has long been controversial, and many studies have compared different approaches. However, there is still a lack of consistent conclusions and comprehensive, systematic comparisons and evaluations. METHODS: This study retrieved 7 databases: PubMed, Web of Science, Embase, Cochrane Library, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and Wanfang Database. The search time ranged from the establishment of each database to November 1, 2023. Data analysis was performed using Review Manager 5.4, and outcome was presented as the weighed mean difference for continuous data and risk/odds ratio for dichotomous data. We used the Mantel-Haneszel method and random effects model to obtain the overall effects of the differences in the impact of 2 surgical methods on clinical outcomes in all included studies. RESULTS: A total of 33 articles were included in this study, including 14478 participants, 4911 participants in DAA group and 9567 participants in PA group. The visual analogue scale scores of the DAA group at 1 day and 2 days after THA were significantly lower than those of the PA group (mean difference [MD] = -0.56, 95% confidence interval [CI]: -0.83 to -0.30, P < .01) at 1 day and (MD = -0.67, 95% CI: -1.16 to -0.17, P = .01) at 2 days. The risk of intraoperative fracture (odds ratio = 2.18, 95% CI: 1.11-4.29, P = .05) and lateral femoral nerve injury (risk ratio = 7.84, 95% CI: 1.69-36.42, P < .01) in the DAA group was significantly higher than that of the PA group. The number of prostheses in the Lewinnek safe zone of the DAA group was significantly higher than that of the PA group (risk ratio = 1.13, 95% CI: 1.00-1.27, P = .05). The results showed no significant difference between the DAA group and the PA group in the time to stop using walking aids, dislocation rate, groin pain, incision complications, heterotopic ossification, intraoperative blood loss, and acetabular anterior (P > .05). CONCLUSION: Compared with the PA group, patients in the DAA group showed more ideal anatomical and imaging results, shorter hospital stay, and showing advantages in postoperative pain, but with a higher incidence of intraoperative complications.

Comparison of mid-term clinical and radiological results of short and conventional femoral stems in total hip arthroplasty.

This study aims to answer the question: Which are superior-conventional or short femoral stems?. An Optymis stem was used as a short-femoral stem, and an Accolade II stem was used as a conventional-femoral stem. There were 95 patients in the short femoral stem group (Group 1) and 90 in the conventional stem group (Group 2). The SF-36 Life Quality Score, thigh pain, and the Harris Hip Score were used to evaluate the patients' clinical outcomes. Pre-operative, immediate post-operative, and final follow-up x-rays were used for radiological evaluation. Stem varus/valgus alignment, hip offset changing, acetabular anteversion/inclination changing, femoral migration, acetabular migration, periarticular ossification, and osteointegration evaluation were assessed for both groups. The mean follow-up time was 5.5 years for Group 1 and 5.2 years for Group 2. No significant difference existed between the two groups in terms of clinical scores (Harris Hip Score, SF-36). Thigh pain was significantly higher in Group 2 (p = 0.0001). As for radiological parameters, Group 1 exhibited more varus position-related results. In terms of angular stability, Group 1 was found to be more unstable than Group 2 (p = 0.0001). The power to reconstruct femoral offset was superior in Group 1. Periarticular ossification was more frequent in Group 2. Femoral osteointegration was denser proximally in Group 1 and distally in Group 2. When mid-term radiological and clinical results of both femoral stems are evaluated, they have no superiority over each other.

Total Hip Arthroplasty with Extra-small Femoral Stems in Extremely Hypoplastic Femurs: A Case-Series Study.

Background: Total hip arthroplasty (THA) in patients with hypoplastic femurs presents a significant challenge to orthopedic surgeons due to the limited space available for implant placement. Therefore, the extra-small femoral stems have been proposed as a solution to this problem, but there are limited data on the outcomes. We aimed to evaluate clinical and radiological outcomes of THA in patients with extremely hypoplastic femurs using the Bencox CM stem (Corentec), an extra-small femoral stem. Methods: We included 6 hips from 4 patients. The mean age of the patients was 41.2 years (range, 19.6-60.4 years). The mean height was 135.1 cm (range, 113.6-150.0 cm) with a mean body mass index of 25.7 kg/m2 (range, 21.3-31.1 kg/m2). The diagnoses for THA were sequelae of septic arthritis in childhood, pseudoachondroplasia, spondyloepiphyseal dysplasia, and juvenile rheumatoid arthritis. Preoperative computed tomography scans were conducted to assess the extent of proximal femoral hypoplasia. The clinical outcomes were assessed using the modified Harris Hip Score, while the radiological outcomes were evaluated using radiographs. The mean follow-up was 2.3 years (range, 1.0-5.9 years). Results: The average modified Harris Hip Score improved to 88.8 at the final follow-up. Intraoperative femoral fractures occurred in 2 cases (33.3%). During the follow-up, 1 stem underwent varus tilting from postoperative 6 weeks to 6 months without subsidence. Otherwise, all stems showed good osteointegration at the latest follow-up. No hip dislocations, periprosthetic joint infection, or loosening of the prosthesis occurred. Conclusions: The use of extra-small femoral stems in THA for extremely hypoplastic femurs can provide reasonable clinical and radiological outcomes with minimal complications. We suggest that this femoral stem could be a viable option for patients with extremely hypoplastic femurs.

Less inflammatory response in the direct anterior than in the direct lateral approach in patients with femoral neck fractures receiving a total hip arthroplasty: exploratory results from a randomized controlled trial.

BACKGROUND AND PURPOSE: It is still debatable which is the least invasive approach to the hip joint in arthroplasty for a femoral neck fracture (FNF). We compared the traditional direct lateral approach (DLA) with the direct anterior approach (DAA) regarding creatine kinase (CK), C-reactive protein (CRP), and hemoglobin (Hb). METHODS: In a randomized controlled trial, 130 elderly patients with dislocated FNFs treated with total hip arthroplasty (THA) were included. CK, CRP, and Hb were measured preoperatively and on postoperative days 1 to 4 and were compared between the DAA and DLA groups using repeated measures mixed-effect models. RESULTS: The CK level was significantly higher on the 1st postoperative day in the DLA group, 597 U/L (95% confidence interval [CI] 529-666) vs 461 U/L (CI 389-532), estimated mean difference (MD) 136 U/L (CI 38-235). The CRP levels were significantly higher on postoperative days 3 and 4 in the DLA group, 207 mg/L (CI 189-226) vs 161 mg/L (CI 143-180), estimated MD 46 mg/L (CI 19-72) and 162 mg/L (CI 144-181) vs 121 (CI 102-140), estimated MD 41 mg/L (CI 15-68). Blood loss, expressed as difference in Hb, did not differ between the groups. CONCLUSION: In an elderly population with FNFs, we found that the DAA, compared with the DLA, results in less CK and CRP increase, but no change in Hb.

Polyethylene liner dissociation in total hip arthroplasty: a retrospective case-control study on a single implant design.

BACKGROUND: Modular acetabular components for total hip arthroplasty (THA) provide intraoperative flexibility; however, polyethylene liner dissociation may occur. This study aimed to examine the incidence and causes of liner dissociation associated with a specific acetabular component design at a single centre. MATERIALS AND METHODS: A retrospective analysis of 7027 patients who underwent primary THA was performed to identify isolated liner dislocations. Patient demographics, clinical presentations, surgical and implant details, and both radiographic and computed tomography (CT) findings were analysed. Patients with liner dislocation were matched to a control group via 2:1 propensity score matching, and a logistic regression analysis was employed to identify associated risk factors. RESULTS: A total of 32 patients (0.45%) experienced liner dislocation at a mean 71.47 ± 60.10 months post surgery. Significant factors contributing to dislocations included the use of a conventional compared with a highly crosslinked polyethylene component (p = 0.049) and screw fixation (p = 0.028). Radiographic and CT analysis highlighted the importance of proper component orientation, revealing that patients experiencing dislocations demonstrated significantly lower acetabular cup anteversion angles (p = 0.001) compared with the control group. Impingement and malposition, identified in 41% and 47% of the cases, respectively, further underscored the multifactorial nature of dislocation risks. CONCLUSIONS: While the overall rate of polyethylene liner dislocation was low, the findings of this study highlight the importance of appropriate cup placement to decrease the risk of dissociation. It further substantiates the influence of impingement and malposition in liner displacement, with increased mechanical stress exerted on the locking mechanism under adverse conditions and the potential risk increase due to screw placement.

Are Metal Ion Levels Elevated After Dual Mobility Acetabular Systems Minimum Five-Year Analysis.

INTRODUCTION: Dual mobility acetabular systems for total hip arthroplasty (THA) have been shown to have decreased dislocation rates and reduced revision rates, but there is controversy over the potential release of sufficient levels of metal ions into the blood to cause adverse local tissue reactions. However, there is a lack of long-term studies analyzing these levels of cobalt and chromium. Therefore, the purpose of this study was to investigate the levels these metal ions at a minimum 5-year follow-up after dual mobility implantation. Specifically, we analyzed: 1. overall blood and urine cobalt levels; 2. overall blood and urine chromium levels; 3. cobalt levels stratified by length of follow-up and various implant-related metrics (i.e., offset, cup size, stem, and neck angle); as well as 4. chromium levels stratified by length of follow-up and these various implant-related metrics. METHODS: A total of 41 patients who underwent THA with modular dual mobility acetabular systems between January 1, 2011, and December 31, 2016, were identified and followed for a mean time of 6 years (range: 5 to 10 years). All patients had well-functioning hips (Harris Hip Scores greater than 90 points (range: 90 to 100 points) and had no evidence of impending radiographic failure or progressive radiolucencies. Cobalt and chromium serum and plasma, blood, as well as urine levels were obtained at final followup. Additional parameters analyzed included: head material and size, stem offset, cup size, as well as stem-neck angle. RESULTS: Concentrations of cobalt were low as the mean blood and urine levels for all patients were 0.6 ± 0.5 µg/L (normal < 1.8 µg/L) and 0.8 ± 0.8 µg/L (normal < 2.8 µg/L), respectively. Only one patient had a minimally elevated blood cobalt level by 0.1 µg/L. These levels were not substantially different when subgroup analyses were performed for ceramic and cobalt-chrome heads. The mean chromium levels in blood and urine were also found to be low for all patients as values were 0.8 ± 0.2 µg/L (normal: < 1.2 µg/L) and 1.2 ± 0.5 ng/milliliter (normal: < 2 ng/L), respectively. Similarly, only one patient had a very slightly elevated blood chromium level of 1.3 µg/L. Additionally, analyses of ceramic or cobalt-chrome heads separately did not demonstrate differences in blood or urine levels. Blood cobalt or chromium concentrations had minimal changes with longer lengths of follow-ups, and with different stem offsets, cup sizes, stems, or neck angles. CONCLUSION: Dual mobility acetabular systems when combined with the two stems studied produced low levels of blood as well as urine cobalt and chromium levels at a minimum follow-up of 5 years (mean: 6 years; range: 5 to 10 years). These results remained below the threshold of normal and clinically insignificant regardless of length of follow-up, head material, or various implant measurements. To the best of our knowledge, this is the first study to demonstrate low levels of metal ions at longer than 4-year follow-up. These data may be of importance to surgeons deciding on the appropriate implants to use for their high-risk patients.

Dual Mobility Versus Fixed Bearing Implants in Primary Total Hip Arthroplasty in Patients Under 55 Years of Age.

INTRODUCTION: Prosthetic dislocation after total hip arthroplasty (THA) is one of the most common causes of revision THA. Dual-mobility (DM) bearings were introduced to mitigate complications; however, there is minimal data on their performance in younger patients. This study compared results of patients who were under 55 years of age undergoing primary THA with DM or fixed-bearing (FB) implants. METHODS: A retrospective review of patients younger than 55 years who underwent primary THA with at least 2 years of follow-up between June 2011 and August 2019 was performed. Patients were stratified into two cohorts based on the implant they received (DM vs. FB). Primary outcomes were 90-day all-cause readmission, dislocation, all-cause revision, 90-day readmission and revision due to dislocation, and implant component survivorship. Demographic differences were assessed using chi-squared and independent samples t-tests. Outcomes were compared using multivariate linear and logistic regressions to control for confounding variables. RESULTS: A total of 803 patients were included (DM = 73, FB = 730). The DM and FB cohorts had similar rates of 90- day all-cause readmission (6.8% vs. 3.2%; p = 0.243) and 90-day readmission due to dislocation (4.1% vs. 0.8%; p = 0.653). At a mean follow-up of 4.42 ± 1.91 years, dislocation (4.1% vs. 1.1%; p = 0.723) and all-cause revision (5.5% vs. 4.9%; p = 0.497) rates between the DM and FB cohorts were similar. Kaplan Meier analysis yielded no significant differences in survivorship between groups for all-cause revision (95.1% vs. 94.5%; p = 0.923), revision due to dislocation (100% vs. 98.9%; p = 0.370), and acetabular component revision (97.3% vs. 98.6%; p = 0.418). CONCLUSION: Dual mobility implants demonstrate similar dislocation rates and implant survivorship compared to FB in patients less than 55 years of age. Larger trials with long-term follow-up may be required to further elucidate the effects of DM bearings compared to FB inserts in younger patients undergoing primary THA.

Effect of epinephrine-mixed fascia iliaca compartment block on bleeding in total hip arthroplasty: A single-center retrospective study.

Fascia iliaca compartment block (FICB) reduces opioid consumption and pain scores after total hip arthroplasty (THA), and has recently been widely applied. We investigated whether FICB could also reduce postoperative bleeding. One hundred and fifteen consecutive patients who underwent elective THA under general anesthesia over 5 months were retrospectively analyzed. They were divided into 2 groups: the FICB group received an epinephrine-mixed FICB procedure and the control group did not receive any block. Using the hematocrit measured at 4 different time points (preoperative and 1, 24, and 48 hours after surgery), the estimated blood loss (EBL) was calculated for 3 different time periods (0-1, 1-24, 24-48 hours after surgery). EBL at 1 to 24 hours (226 vs 398 mL, P = .008) was significantly lower in the FICB group than in the control group. Additionally, the number of packed red cell (PRC) units transfused per patient over 48 hours was 0.38 units in the FICB group, which was significantly lower than the 0.70 units used in the control group (P = .040). Epinephrine-mixed FICB in THA has the potential to reduce postoperative bleeding in the first 24 hours after surgery as well as reduce PRC transfusion requirements.

Intraoperative cell salvage reduces postoperative allogeneic blood transfusion and shortens off-bed time in simultaneous bilateral total hip arthroplasty: a single-center retrospective study.

BACKGROUND: Simultaneous bilateral total hip arthroplasty (SI-THA) results in more blood loss and a greater need for postoperative allogeneic blood transfusion (ABT). Previous studies have reported that multimodal patient blood management (PBM) strategies were associated with a smaller effect of intraoperative cell salvage (ICS) in unilateral total hip arthroplasty. However, there are few studies on the role of ICS in SI-THA. This study aims to explore the effect of ICS with multimodal PBM strategies on SI-THA and to identify risk factors associated with ABT. METHODS: This retrospective matched cohort study included 72 patients in the ICS group and 72 patients in the control group who were matched according to age, sex, and year of hospitalization. Demographic data, hematological indicators, blood loss, and ABT were compared between the two groups. Logistic regression analysis was performed to identify independent risk factors for postoperative ABT. Postoperative outcomes were also recorded. RESULTS: In the cohort of 144 patients, 27 patients (37.5%) in the ICS group while 45 patients (62.5%) in the control group received postoperative ABT after SI-THA. Compared with the control group, the ICS group showed significant differences in terms of blood loss, postoperative hemoglobin and hematocrit. The transfused volume of allogeneic red blood cells per ABT patient was also lower in the ICS group. Multivariate logistic regression analysis indicated that sex, the utilization of ICS, and preoperative hematocrit level were identified as independent factors associated with postoperative ABT. The utilization of ICS significantly shortened off-bed time and length of hospital stay, but had no effect on early pain and functional outcomes. CONCLUSION: The utilization of ICS can significantly affect postoperative ABT in SI-THA patients with multimodal PBM strategies. Sex, the utilization of ICS and preoperative hematocrit level were identified as independent factors associated with postoperative ABT. The utilization of ICS promoted weight-bearing functional exercises, but had no effect on early outcomes.

Bispherical metal augment improved biomechanical stability in severe acetabular deficiency reconstruction: a comparative finite element analysis.

BACKGROUND: This study used finite element analysis (FEA) to compare the biomechanical stability of bispherical metal augment (BA) and wedge-shaped trabecular-metal augment (TA) in different acetabular defect reconstruction models, thereby explaining the application value of this novel bispherical augment in complex hip revision. METHODS: Three different acetabular defect pelvis models originating from three representative patients with different types of severe acetabular defects (Paprosky IIC, IIIA, and IIIB) were constructed and reconstruction with BA and TA technique was simulated. Based on the FEA models, the displacement of reconstruction implants, relative displacement of bone implants, and hemi-pelvic von Mises stress were investigated under static loads. RESULTS: BA acquired smaller reconstruction system displacement, less relative displacement of bone implants, and lower pelvic von Mises stress than TA in all Paprosky IIC, IIIA, and IIIB defect reconstructions. CONCLUSION: The FEA results show that BA could acquire favourable biomechanical stability in severe acetabular defect reconstruction. This technique is a reliable method in complex hip revision.

[The reconstruction techniques and mid-term clinical outcomes of hip revision for acetabular bone defect after total hip arthroplasty].

Objective: To analyze three reconstruction techniques and mid-term clinical outcomes of hip revision for acetabular bone defect after total hip arthroplasty (THA). Methods: This is a retrospective case series study. Included in the study were 109 patients (109 hips) with acetabular bone defect after THA reconstructions in hip revisions from January 2015 to December 2021 in the Senior Department of Orthopaedics, the Forth Medical Center of Chinese People's Liberation Army General Hospital and the Department of Orthopaedics, the First Medical Center of Chinese People's Liberation Army General Hospital. According to the preoperative simulated surgeries and different bone defect reconstruction techniques, patients were divided into a normal cup group, an augment group or a triflange group,respectively. There were 54 patients (54 hips) in the normal cup group, reconstructed with the uncemented porous metal cup (including Jumbo cup), with 23 males and 31 females, aged (59.6±9.9) years (range:32 to 76 years); 44 patients (44 hips) in the augment group, reconstructed with the individualized three-dimensional (3D) printed porous metal augment and uncemented porous metal cup, with 18 males and 26 females, aged (52.8±13.6) years(range:17 to 76 years); 11 patients (11 hips) in the triflange group, reconstructed by the individualized 3D printed porous metal triflange cup, with 5 males and 6 females, aged (59.4±11.2) years (range: 43 to 78 years). Radiographic results, including rotation center height, rotation center offset, and leg length discrepancy (LLD) and clinical results, including Harris hip score (HHS) and visual analogue scale(VAS) were evaluated outpatient at 3, 6, 12 months after the operation and annually thereafter. The last follow-up was completed in March 2024, and all parameters at the last follow-up and before the operation were compared. Paired sample t test and repeated measurement ANOVA were used for the radiographic and clinical parameters before and after the operation. Results: All hip revisions for patients with acetabular bone defect after THA were completed and followed for more than two years. The follow-up time of the normal cup group was (6.5±1.7) years (range: 2.8 to 9.3 years), and that of the augment group was (6.0±1.3) years (range: 3.5 to 9.0 years). The follow-up time of the triflange group was (2.8±0.6) years (range: 2.0 to 3.8 years). At the last follow-up, the rotation center height, rotation center offset and LLD of 54 hips in the normal cup group were (24.2±5.6) mm, (29.1±5.5) mm and (4.6±3.3) mm, respectively, and the rotation center height and LLD were significantly lower than those of the preoperative hips (t=9.671, P<0.01; t=6.073, P<0.01). In the augment group, the rotational center height, the rotation center offset and the LLD of 44 hips were (22.4±9.0) mm, (25.4±5.5) mm and (6.0±4.0) mm, respectively, which were significantly lower than those of the preoperative hips (t=9.071, P<0.01; t=11.345, P<0.01; t=4.927, P<0.01). In the triflange group, the rotational center height, the rotation center offset and LLD of 11 hips were (22.7±6.0) mm,(30.9±8.0) mm and (5.3±2.2) mm, respectively, and the rotation center height and LLD were significantly lower than those of the preoperative hips (t=2.716, P=0.022; t=6.226, P<0.01). At the last follow-up, fractures occurred in 3 patients and dislocation occurred in 1 patient in the normal cup group, and fracture reduction and closed reduction were administered under anesthesia, respectively. In the augment group, dislocation occurred in 1 patient and open reduction under anesthesia was performed. The HHS and VAS of the three groups improved significantly after surgery and the differences were statistically significant (all P<0.01). There was no complication in the triflange group. The X-ray at the last follow-up showed that all prostheses and augments were in stable positions and no loosening or migration was observed. Conclusions: For patients with acetabular bone defect after THA undergoing hip revisions, preoperative surgical simulation and rehearsal could help surgeons choose convenient and efficient reconstruction techniques. The targeted selection of Jumbo cup, individualized 3D printed metal augment, and customized triflange cup could achieve satisfactory clinical outcomes.

[Management of acetabular bone defect in revision hip arthroplasty].

The number of hip revision surgeries is expected to increase in recent years, and reconstruction of acetabular defects is a challenge for joint surgeons. The principle of reconstruction of acetabular defects is to achieve initial and long-term stability between the prosthesis and the host bone. With the development of surgical techniques, prosthetic materials, and revision concepts, there is an urgent need for new acetabular bone defect evaluation systems to meet clinical needs. The uncemented porous hemispherical cup has become the main prosthesis in clinical application, and metal augments are gradually replacing the structural allograft. Modular reconstruction combined cups and augments has shown favorable clinical results, which can be used for large acetabular defects with acetabular distraction technique, such as pelvic discontinuity. The advantages and disadvantages of impaction bone grafting, jumbo cups, metal augments, acetabular reinforcement rings, custom components (including custom triflanged acetabular components), and acetabular distraction technique still need to be observed in long-term follow-up.

[One-stage revision for reconstructing acetabular defects by trabecular metal acetabular revision system in periprosthetic joint infection].

Objective: To investigates the clinical efficacy of the trabecular metal acetabular revision system (TMARS) in one-stage reconstruction of acetabular deficiencies associated with periprosthetic joint infection (PJI). Methods: This is a retrospective case series study,including the data of 59 patients with PJI underwent acetabular defect reconstruction by TMARS during one-stage revisions in the Department of Orthopaedics, the First Affiliated Hospital of Xinjiang Medical University from January 2013 to December 2021. There were 32 males and 27 females, aged (59.5±14.6) years (range: 26 to 84 years). Among them, 29 cases used tantalum cups, 13 cases used tantalum cups and tantalum reinforcing blocks, 9 cases used cup-cage, and 8 cases used multi-cup reconstruction techniques. The surgery procedure, Harris Hip score (HHS), recovery of the hip rotation center, implant survival rate, postoperative reinfection rate, and complications were recorded. Data were compared using the Wilcoxon rank-sum test. Results: All of the 59 patients underwent the operations successfully. Operation time was (188.9±48.4) minutes (range: 110 to 340 minutes), and intraoperative bleeding volume was (M(IQR)) 1 000(400)ml (range: 600 to 1 800 ml). After a postoperative follow-up of 5.1 (2.6) years (range: 2.0 to 10.5 years), the prosthesis survival rate was 94.9% (56/59). Recurrence of infection occurred in 3 cases (5.1%), aseptic loosening in 1case(1.7%), and hip dislocation in 4 cases (6.8%). At the last follow-up, HHS improved significantly(84 (12) vs. 44 (9), Z=-6.671, P<0.01), and the center of rotation of the hips were recovered in all cases. Conclusions: In one-stage revision surgeries aimed at reconstructing acetabular defects, utilizing the TMARS can provide stable initial fixation, restore a more natural center of rotation, significantly enhance early postoperative hip joint function, and reduce the likelihood of infection recurrence. This approach stands as a reliable choice for addressing acetabular defects during revision surgeries for infected hip joints.

Correction of Acquired Leg Length Discrepancy after Hip Resurfacing Arthroplasty by Revision Resurfacing: A Case Report.

CASE: A 53-year-old man presented with a 13-mm leg length discrepancy following left hip resurfacing arthroplasty (HRA), resulting in pain and imbalance. Advanced osteoarthritis of the contralateral hip was also noted. The patient strongly preferred HRA over total hip arthroplasty. Adequate remaining bone stock and the ability to resurface the contralateral hip allowed for resolution with 2 HRAs. CONCLUSION: This is the first known revision of a HRA with a subsequent HRA. Assuming sufficient bone stock and precise implant positioning, resurfacing presents a feasible methodology to overcome complex anatomical deformities and improve mobility.

Best timing of bilateral total hip arthroplasty - an analysis of revision and mortality rates from the German Arthroplasty Registry (EPRD).

BACKGROUND: The burden of osteoarthritis (OA) in multiple joints is high and for patients with bilateral OA of the hip there is no clear recommendation about the indication for simultaneous (one-stage) bilateral total hip arthroplasty (THA) versus two-staged procedures. The purpose of this study was therefore to compare revision and mortality rates after different strategies of surgical timing in bilateral hip OA from the German Arthroplasty Registry (EPRD). METHODS: Since 2012 22,500 patients with bilateral THA (including 767 patients with one-staged bilateral surgery and 11,796 patients with another separate procedures within one year after first THA) are documented in the registry. The patients who underwent simultaneous bilateral THA were matched with a cohort of 767 patients who underwent the second THA between 1 and 90 days postoperatively (short interval) and another cohort of 4,602 patients with THA between 91 and 365 days postoperatively (intermediate interval). Revision for all reasons and mortality rates were recorded. Cox regression was performed to evaluate the influence of different patient characteristics. RESULTS: The cumulative 5-year revision rate for patients with simultaneous bilateral THA was 1.8% (95% CI 0.9-2.6), for patients with two-staged THA 2.3% (95% CI 1.0-3.6) in the short interval and 2.5% (95% CI 2.1-2.9) in the intermediate interval, respectively. In all three groups, patients who underwent THA in a high-volume center (≥ 500 THA per year) had a significant lower risk for revision (HR 0.687; 95% CI 0.501-0.942) compared to surgeries in a low-volume center (< 250 THA per year). There was no significant difference regarding cumulative mortality rates in the three cohorts. Higher age (HR 1.060; 95% CI 1.042-1.078) and severe comorbidities as reflected in the Elixhauser Score (HR 1.046; 95% CI 1.014-1.079) were associated with higher mortality rates after simultaneous THA. CONCLUSION: Simultaneous bilateral THA seems to be a safe procedure for younger patients with limited comorbidities who have bilateral end-stage hip OA, especially if performed in high-volume centers. LEVEL OF EVIDENCE: III.