Conversion Total Hip Arthroplasty in Patients With Osteopetrosis: Insights From Two Unique Cases.

CASE: Two patients with osteopetrosis underwent conversion total hip arthroplasty (THA) after failure of internal fixation due to hip fractures. We experienced challenges, including difficulty of hardware removal, remaining of previous broken screws in the canal, difficulty in finding the femoral canal, and an intraoperative acetabulum fracture. Despite complications, both patients achieved satisfactory functional outcome after surgery at the latest follow-up. CONCLUSION: Our cases showed that previous hip fracture and failed internal fixation make conversion THA more complex and unpredictable in patients with osteopetrosis. This in turn underscores the critical need for advanced preoperative planning, intraoperative flexibility, and meticulous postoperative care.

Accuracy of cup placement compared with preoperative surgeon targets in primary total hip arthroplasty using standard instrumentation and techniques: a global, multicenter study.

BACKGROUND: Acetabular cup positioning in total hip arthroplasty (THA) is closely related to outcomes. The literature has suggested cup parameters defined by the Lewinnek safe zone; however, the validity of such measures is in question. Several studies have raised concerns about the benefits of using the Lewinnek safe zone as a predictor of success. In this study we elected to use prospective surgeon targets as the basis for comparison to see how successful surgeons are positioning their cup using standard instruments and techniques. METHODS: A prospective, global, multicenter study was conducted. Cup positioning success was defined as a composite endpoint. Both cup inclination and version needed to be within 10° of the surgeon target to be considered a success. Radiographic analysis was conducted by a third-party reviewer. RESULTS: In 170 subjects, inclination, target versus actual, was 44.8° [standard deviation (SD 0.9°)] and 43.1° (SD 7.6°), respectively (p = 0.0029). Inclination was considered successful in 84.1% of cases. Mean version, target versus actual, was 19.4° (SD 3.9°) and 27.2° (SD 5.6°), respectively (p < 0.0001). Version was considered successful in 63.4% of cases, and combined position (inclination and version) was considered successful in 53.1%. CONCLUSION: This study shows that with traditional methods of placing the cup intraoperatively, surgeons are only accurate 53.1% of the time compared with a predicted preoperative plan. This study suggests that the inconsistency in cup positioning based on the surgeon's planned target is potentially another important variable to consider while using a mechanical guide or in freehand techniques for cup placement in THA. TRIAL REGISTRATION: This study is registered on ClinicalTrials.gov, NCT03189303.

Autologous concentrated bone marrow injection for precollapse osteonecrosis of the femoral head concurrent with contralateral total hip arthroplasty: protocol for a clinical trial.

INTRODUCTION: The femoral head contralateral to the collapsed femoral head requiring total hip arthroplasty (THA) often manifests in the precollapse stage of osteonecrosis of the femoral head (ONFH). It is not yet demonstrated how autologous concentrated bone marrow injection may prevent collapse of the femoral head concurrent with contralateral THA. The primary objective is to evaluate the efficacy of autologous concentrated bone marrow injection for the contralateral, non-collapsed, femoral head in patients with bilateral ONFH, with the ipsilateral collapsed femoral head undergoing THA. METHODS AND ANALYSIS: This is a multicentre, prospective, non-randomised, historical-data controlled study. We will recruit patients with ONFH who are scheduled for THA and possess a non-collapsed contralateral femoral head. Autologous bone marrow will be collected using a point-of-care device. After concentration, the bone marrow will be injected into the non-collapsed femoral head following the completion of THA in the contralateral hip. The primary outcome is the percentage of femoral head collapse evaluated by an independent data monitoring committee using plain X-rays in two directions 2 years after autologous concentrated bone marrow injection. Postinjection safety, adverse events, pain and hip function will also be assessed. The patients will be evaluated preoperatively, and at 6 months, 1 year and 2 years postoperatively. ETHICS AND DISSEMINATION: This protocol has been approved by the Certified Committee for Regenerative Medicine of Tokyo Medical and Dental University and Japan's Ministry of Healthy, Labour and Welfare and will be performed as a class III regenerative medicine protocol, in accordance with Japan's Act on the Safety of Regenerative Medicine. The results of this study will be submitted to a peer-review journal for publication. The results of this study are expected to provide evidence to support the inclusion of autologous concentrated bone marrow injections in the non-collapsed femoral head in Japan's national insurance coverage. TRIAL REGISTRATION NUMBER: jRCTc032200229.

Language-adaptive artificial intelligence: assessing CHATGPT'S answer to frequently asked questions on total hip arthroplasty questions.

ChatGPT is reported to be an acceptable tool to answer a majority of frequently asked patient questions. ChatGPT also converses in other languages including Urdu, which offers immense potential for the education of Pakistani patients. Therefore, this study evaluated ChatGPT's Urdu answers to the ten most frequently asked questions on Total Hip Arthroplasty, which were then rated by an expert. Out of 10 answers in English, 9 (90%) were satisfactory requiring minimal clarification and 1 (10%) was satisfactory requiring moderate clarification. In both Roman and Nastaliq script Urdu, 1 (10%) answer was satisfactory requiring moderate clarification, while 9 (90%) were unsatisfactory requiring substantial clarification. In conclusion, as opposed to ChatGPT English responses, Urdu responses were much less rigorous, generic, and lacked scientific rigor. We have a long way to go before Pakistani patients with limited English language skills could benefit from AI chatbots like ChatGPT.

Implementation of outpatient hip and knee arthroplasty in a multicenter public healthcare setting.

BACKGROUND AND PURPOSE: Length of hospital stay after hip and knee arthroplasty is about 1 day in Denmark with few patients discharged on the day of surgery. Hence, a protocol for multicenter implementation of discharge on day of surgery has been instituted. We aimed to describe the implementation of outpatient hip and knee arthroplasty in a multicenter public healthcare setting. METHODS: We performed a prospective multicenter study from 7 public hospitals across Denmark. Patients were screened using well-defined in- and exclusion criteria and were discharged on day of surgery when fulfilling functional discharge criteria. The study period was from September 2022 to February 2023 with variable start of implementation. Data from the same centers in a 6-month period before the COVID pandemic from July 2019 to December 2019 was used for baseline control. RESULTS: Of 2,756 primary hip and knee arthroplasties, 37% (95% confidence interval [CI] 35-39) were eligible (range 21-50% in centers) and 52% (range 24-62%) of these were discharged on day of surgery. 21% (CI 20-23) of all patients (eligible and non-eligible) were discharged on day of surgery with a range of 10-31% within centers. This was an additional 15% (CI 13-17, P < 0.001) compared with patients discharged in the control period (6% in 2019). CONCLUSION: We found it possible to perform outpatient hip and knee replacement in 21% of patients in a public healthcare setting, probably to be increased with further center experience.

Mini-Navigation Utilization in THA Results in Shorter Length of Stay, Increased Home Discharge, and Higher Physical Therapy Mobilization Scores Compared to THA Without Navigation.

BACKGROUND: As volume of total hip arthroplasty (THA) continues to increase, the utilization and availability of in-traoperative advanced technologies to arthroplasty surgeons continues to rise as well. Our primary goal was to determine whether the use of a mini navigation technology extended operative times and secondarily if it affected postoperative outcomes following elective THA. METHODS: A single-institution total joint arthroplasty da-tabase was utilized to identify adult patients who underwent elective THA from 2017 to 2019. Baseline demographic data along with surgical operative time, length of stay (LOS) and discharge disposition were collected. The Activity Measure for Post-Acute Care (AM-PAC) was used to determine physi-cal therapy progress. RESULTS: A total of 1,162 THAs were performed of which 69.1% (803) used navigation while 30.9% (359) did not. Baseline demographics including age, sex, body mass index (BMI), insurance, and smoking status were not statistically different between groups. The operative time was shorter in the navigation group compared to THA without navigation (115.1 vs. 118.9 min, p < 0.0001). Mean LOS was signifi-cantly shorter in the navigation THA group as compared to THA without navigation (2.1 vs. 2.6 days, p < 0.0001). Postoperative AM-PAC scores were higher in the navigation group on postoperative day 1 as compared to patients with-out navigation (18.87 vs. 17.52, p < 0.0001). Additionally, a greater percentage of patients were discharged directly home after THA with navigation as compared to THA without navigation (89.54% vs. 83.57%, p < 0.0001). CONCLUSION: Our study demonstrates that hip navigation technology in the setting of THA is associated with reduced operative times and higher AM-PAC mobilization scores. Hip mini navigation technology shortens operative times while improving early patient outcome scores in association with shorter LOS and greater home-based discharge.

Outcomes in Arthroplasty Procedures Performed for Femoral Neck Fractures Does Approach Affect Outcome?

BACKGROUND: The surgical approach used for arthroplasty in the setting of hip fracture has traditionally been decided based on surgeon preference. This study analyzed the ef-fect of the surgical approach on hospital quality measures, complications, and mortality in patients treated with hip arthroplasty for fracture fixation. METHODS: A cohort of consecutive acute hip fracture pa-tients who were 60 years of age or older and who underwent hemiarthroplasty (HA) or total hip arthroplasty (THA) at one academic medical center between January 2014 and January 2018 was included. Patient demographics, length of stay (LOS), surgery details, complications, ambulation at dis-charge, discharge location, readmission, and mortality were recorded. Two cohorts were included based on the surgical approach: the anterior-based cohort included the direct an-terior and anterolateral approaches and the posterior-based cohort included direct lateral and posterior approaches. RESULTS: Two hundred five patients were included: 146 underwent HA (81 anterior-based and 65 posterior-based) and 79 underwent THA (37 anterior-based and 42 posterior-based). The mean age of the HA and THA cohorts was 84.1 ± 7.5 and 73.7 ± 8.0 years, respectively. There was no dif-ference in LOS, time to surgery, or surgical time between the two cohorts for HA and THA. There were no differences in perioperative complications, including dislocation, ob-served based on surgical approach. No difference was found between readmission rates and mortality. CONCLUSION: In this cohort of hip fracture arthroplasty patients, there was no difference observed in hospital quality measures, readmission, or mortality in patients based on sur-gical approach. These results are in contrast with literature in elective arthroplasty patients supporting the use of an anterior approach for potential improved short-term outcomes.

Elevated cobalt levels in metal-on-polyethylene knee megaprostheses: a prospective 1-year cohort study of 56 patients with hip and knee megaprostheses.

BACKGROUND AND PURPOSE: Concerns have emerged regarding elevated levels of cobalt and chromium in patients with metal-on-metal megaprostheses. This prospective study aims to identify systemic cobalt and chromium levels in metal-on-polyethylene knee and hip megaprostheses and their associations with other factors. METHODS: 56 patients underwent knee or hip megaprosthesis surgery at 2 sarcoma centers. Serum cobalt and chromium levels were measured preoperatively and thrice within the first year using inductively coupled plasma mass spectrometry. RESULTS: A statistically significant difference in serum cobalt levels (1.4 ppb; 95% confidence interval [CI] 0.0-3.3) was observed 1 year after knee megaprosthesis surgery compared with preoperative levels. In contrast no difference in chromium levels was observed after 1 year compared with preoperative levels (0.05 ppb; CI 0.0-0.8). An association between younger age, higher eGFR, and increased cobalt levels was observed. No significant correlations were found between ion levels and resection length or the number of modular connections. CONCLUSION: We found elevated serum ion levels in metal-on-polyethylene knee megaprostheses in contrast to metal-on-polyethylene hip megaprostheses. Furthermore, a positive correlation between cobalt and chromium levels, and between cobalt and eGFR was identified, along with a negative correlation between cobalt and age. This study highlights the importance of monitoring systemic cobalt and chromium levels in patients with megaprostheses.

[Frequency of spinopelvic alterations in postoperative total hip arthroplasty patients and their association with functional outcomes]. / Frecuencia de alteraciones espinopélvicas en pacientes postoperados de artroplastía total de cadera y su asociación con resultados funcionales.

INTRODUCTION: the analysis of spinopelvic imbalance in patients undergoing total hip arthroplasty has gained significance in recent years, being recognized as a risk factor for instability. Few reports exist regarding the prevalence of spinopelvic alterations in Latin American literature. The aim of this study is to determine the frequency of spinopelvic imbalance in our patients and to associate them with functional outcomes. MATERIAL AND METHODS: 29 patients who underwent total hip arthroplasty using a lateral approach (32 arthroplasties) were included. All patients completed clinical outcome questionnaires preoperatively. Twelve months after surgery, they underwent anteroposterior pelvic and lateral pelvic X-rays, both standing and sitting, and clinical outcome questionnaires were completed. The radiographic parameters examined were: pelvic incidence, lumbar lordosis, sacral slope, anterior pelvic plane and pelvic femoral angle. Functional outcome was assessed with the Harris Hip Score and WOMAC scales. Patients were classified according to their spinopelvic alteration and statistical analysis was performed to identify significant differences between the groups and the correlation with functional outcomes. RESULTS: there was a high frequency of spinopelvic balance alterations (46.8%); 6.2% (n = 2/32) presented isolated spinal stiffness (group 1B), 37.5% (n = 12/29) spinal deformity without spinal stiffness (group 2A) and 3.1% (n = 1/29) spinal deformity associated with stiffness (group 2B). We found no improvement in HHS and WOMAC scores in the groups with spinal stiffness (1B and 2B) (p = 0.98 y 0.15). There is association between spinal stiffness (SS < 10°) and poor functional outcomes (p = 0.02). CONCLUSIONS: the frequency of spinopelvic balance alterations was high. While there was no observed rise in prosthetic dislocations, the existence of spinal stiffness, defined by a SS of less than 10°, was associated to poor outcomes on functional scales.

INTRODUCCIÓN: el análisis de las alteraciones del balance espinopélvico en pacientes sometidos a artroplastía total de cadera ha adquirido importancia en años recientes, siendo reconocido como un factor de riesgo para inestabilidad. Existen pocos reportes de la prevalencia de alteraciones espinopélvicas en literatura latinoamericana. El objetivo de esta investigación es determinar la frecuencia de alteraciones del balance espinopélvico en nuestros pacientes y su asociación con los resultados funcionales. MATERIAL Y MÉTODOS: se incluyeron 29 pacientes intervenidos de artroplastía total de cadera mediante abordaje lateral (32 artroplastías). Todos los pacientes completaron escalas funcionales preoperatoriamente. A los 12 meses de la intervención, se valoró el balance espinopélvico mediante radiografías anteroposterior de pelvis y laterales de pelvis tanto de pie como en sedestación y completaron escalas funcionales. Los parámetros radiográficos valorados fueron: incidencia pélvica, lordosis lumbar, inclinación del sacro (sacral slope), plano pélvico anterior y ángulo pélvico femoral. El estado funcional se valoró con las escalas Harris Hip Score (HHS) y WOMAC. Se clasificó a los pacientes de acuerdo a su alteración espinopélvica y se realizó análisis estadístico para identificar diferencias significativas entre los grupos y la asociación con resultados funcionales. RESULTADOS: encontramos una elevada frecuencia de alteraciones del balance espinopélvico (46.8%); 6.3% (n = 2/32) presentaron rigidez espinal aislada (grupo 1B), 37.5% (n = 12/29) deformidad espinal sin rigidez espinal (grupo 2A) y 3.1% (n = 1/29) deformidad espinal asociada a rigidez (grupo 2B). En los grupos con rigidez espinal (1B y 2B) no hubo mejoría significativa en HHS y WOMAC (p = 0.98 y 0.15). Encontramos asociación entre la presencia de rigidez espinal (SS < 10°) y resultados funcionales subóptimos con valor de p = 0.02. CONCLUSIONES: la frecuencia de alteraciones en el balance espinopélvico fue elevada. A pesar de no verse reflejado en un aumento en la incidencia de luxaciones protésicas, la presencia de rigidez espinal caracterizada por un SS menor a 10° se asoció con resultados subóptimos en las escalas funcionales.

Sex-based differences in neck selectivity in total hip arthroplasty using a modular femoral neck system.

BACKGROUND: Dislocation is a major complication of total hip arthroplasty (THA). The modular femoral neck system provides practical advantages by allowing adjustment of neck version and length in the presence of intraoperative instability. Anatomical studies have identified morphological differences in the hip joint between men and women. Despite sex-based differences in hip morphology, it remains unclear whether such differences affect neck selectivity in THA using a modular neck system and whether this approach achieves anatomical reconstruction, thereby reducing complications such as dislocation. This study aimed to investigate gender differences in neck selectivity in THA with the modular neck system and assess the clinical impact of the modular neck system. METHODS: A total of 163 THAs using a modular neck system were included in this study. Data on the type of modular neck and intraoperative range of motion (ROM) were retrieved from patient records. Pre- and post-operative leg length differences (LLD) were examined as part of the radiographic assessment. Dislocation was investigated as a postoperative complication. RESULTS: Neck selectivity did not significantly differ between men and women. The comparison of pre- and post-operative LLD revealed a tendency for varus necks to improve LLD more than version-controlled necks. Furthermore, no significant correlation was found between intraoperative ROM and neck selectivity, or postoperative dislocation and neck selectivity. CONCLUSIONS: This study on THA with a modular neck system provided valuable insights into sex-based differences in neck selectivity and highlighted the potential benefits of the modular neck system in addressing LLD and preventing postoperative dislocation.

The influence of surgical technique guidance and surgeon's experience on the femoral head assembly in total hip arthroplasty.

INTRODUCTION: The importance of the assembly procedure on the taper connection strength is evident. However, existent surgical technique guides frequently lack comprehensive and precise instructions in this regard. The aim of our experimental study was to evaluate the influence of the surgical technique guide on the femoral head assembly procedure in surgeons with differing levels of experience in total hip arthroplasty. MATERIALS AND METHODS: Twenty-eight participants, divided into four groups based on their lifetime experience in total hip arthroplasty, conducted a femoral head assembly procedure in a simulated intraoperative environment before and after reviewing the surgical technique guide. Demographic information and the number of hammer blows were documented. Hammer velocity and impaction angle were recorded using an optical motion capturing system, while the impaction force was measured using a dynamic force sensor within the impactor. RESULTS: We observed a high variation in the number of hammer blows, maximum force, and impaction angle. Overall, the number of hammer blows decreased significantly from 3 to 2.2 after reviewing the surgical technique guide. The only significant intragroup difference in the number of hammer blows was observed in the group with no prior experience in total hip arthroplasty. No correlation was found between individual factors (age, weight, height) or experience and the measured parameters (velocity, maximum force and angle). CONCLUSIONS: The present study demonstrated a high variation in the parameters of the femoral head assembly procedure. Consideration of the surgical technique guide was found to be a limited factor among participants with varying levels of experience in total hip arthroplasty. These findings underline the importance of sufficient preoperative training, to standardize the assembly procedure, including impaction force, angle, and use of instruments.

Study on impact of robotic-assisted orthopaedic industrial noise (SIREN).

INTRODUCTION: The aim of this study was to evaluate noise exposure to the operating room staff consisting of the surgeon, assistant, anaesthetist and Mako Product Specialist (MPS) during Mako robotic-arm assisted total knee arthroplasty (TKA) and total hip arthroplasty (THA). We aimed to determine whether employees were exposed to noise at or above a lower exposure action value (LEAV) set out by the Noise at Work Regulations 2005, Health and Safety Executive (HSE), UK. MATERIALS AND METHODS: We prospectively recorded intra-operative noise levels in Mako robotic-arm assisted TKA and THA over a period of two months using the MicW i436 connected to an iOS device (Apple), using the Sound Level Meter App (iOS) by the National Institute for Occupation Safety and Health (NIOSH). Data obtained was then used to calculate "worst case" daily exposure value to assess if sound levels were compliant with UK guidelines. Comparison between operating room staff groups was performed with ANOVA testing. RESULTS: A total of 19 TKA and 11 THA operations were recorded. During TKA, for the primary surgeon and the assistant, the equivalent continuous sound pressure level (LAeq) was over 80 dB, exceeding the LEAV set out by the Noise at Work Regulations by HSE. During THA, the average LAeq and peak sound pressure levels did not exceed the LEAV. The calculated daily exposure for the primary surgeon in TKA was 82 dB. A Tukey post hoc test revealed that LAeq was statistically significantly lower in the anaesthetist and MPS (p < .001) compared to the primary surgeon and assistant in both TKA and THA. CONCLUSIONS: Operating room staff, particularly the primary surgeon and assistant are exposed to significant levels of noise during Mako robotic-arm assisted TKA and THA. Formal assessments should be performed to further assess the risk of noise induced hearing loss in robotic-arm assisted arthroplasty.

Equivalent revision rates and patient reported outcomes with routine use of a short (125mm) cemented stem for total hip arthroplasty compared to a standard length (150mm) cemented stem. A two surgeon series of 1335 patients.

BACKGROUND: Routine total hip arthroplasty (THA) using a short cemented stem as compared with a standard length cemented stem may have benefits in terms of stress distribution, bone preservation, stem subsidence and ease of revision surgery. Two senior arthroplasty surgeons transitioned their routine femoral implant from a standard 150 mm Exeter V40 cemented stem to a short 125 mm Exeter V40 cemented stem for all patients over the course of several years. We analysed revision rates, adjusted survival, and PROMS scores for patients who received a standard stem and a short stem in routine THA. METHODS: All THAs performed by the two surgeons between January 2011 and December 2021 were included. All procedures were performed using either a 150 mm or 125 mm Exeter V40 stem. Demographic data, acetabular implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the New Zealand Joint Registry (NZJR), and detailed survival analyses were performed. Primary outcome was revision for any reason. Reason for revision, including femoral or acetabular failure, and time to revision were also recorded. RESULTS: 1335 THAs were included. 516 using the 150 mm stem and 819 using the 125 mm stem. There were 4055.5 and 3227.8 component years analysed in the standard stem and short stem groups respectively due to a longer mean follow up in the 150 mm group. Patient reported outcomes were comparable across all groups. Revision rates were comparable between the standard 150 mm stem (0.44 revisions/100 component years) and the short 125 mm stem (0.56 revisions/100 component years) with no statistically significant difference found (p = 0.240). CONCLUSION: Routine use of a short 125 mm stem had no statistically significant impact on revision rate or PROMS scores when compared to a standard 150 mm stem. There may be benefits to routine use of a short cemented femoral implant.

Is AI 3D-printed PSI an accurate option for patients with developmental dysplasia of the hip undergoing THA?

BACKGROUND: In traditional surgical procedures, significant discrepancies are often observed between the pre-planned templated implant sizes and the actual sizes used, particularly in patients with congenital hip dysplasia. These discrepancies arise not only in preoperative planning but also in the precision of implant placement, especially concerning the acetabular component. Our study aims to enhance the accuracy of implant placement during Total Hip Arthroplasty (THA) by integrating AI-enhanced preoperative planning with Patient-Specific Instrumentation (PSI). We also seek to assess the accuracy and clinical outcomes of the AI-PSI (AIPSI) group in comparison to a manual control group. METHODS: This study included 60 patients diagnosed with congenital hip dysplasia, randomly assigned to either the AIPSI or manual group, with 30 patients in each. No significant demographic differences between were noted the two groups. A direct anterior surgical approach was employed. Postoperative assessments included X-rays and CT scans to measure parameters such as the acetabular cup anteversion angle, acetabular cup inclination angle, femoral stem anteversion angle, femoral offset, and leg length discrepancy. Functional scores were recorded at 3 days, 1 week, 4 weeks, and 12 weeks post-surgery. Data analysis was conducted using SPSS version 22.0, with the significance level was set at α = 0.05. RESULTS AND CONCLUSION: The AIPSI group demonstrated greater prosthesis placement accuracy. With the aid of PSI, AI-planned THA surgery provides surgeons with enhanced precision in prosthesis positioning. This approach potentially offers greater insights and guidelines for managing more complex anatomical variations or cases.

Accuracy of portable navigation during THA in patients with severe developmental dysplasia of hip.

INTRODUCTION: Correct cup placement in total hip arthroplasty (THA) for patients with developmental dysplasia of the hip (DDH) is considerably difficult. This study aimed to analyze the orientation accuracy of cup insertion during THA using a portable navigation system in patients with DDH. MATERIALS AND METHODS: In this retrospective cohort study, we analyzed data from 64 patients who underwent THA using infrared stereo camera-matching portable navigation. Patients underwent THA via the anterolateral approach in the lateral decubitus position. Navigation records for intraoperative cup angles, postoperative cup angles measured on computed tomography (CT) images, and cup angle measurement differences were measured and compared between patients with non-DDH/mild DDH and severe DDH. Furthermore, the predictive factors for outliers of accurate acetabular cup placement were analyzed. RESULTS: The average measurement absolute abduction differences (postoperative CT-navigation record) were 3.9 ± 3.5° (severe DDH) and 3.3 ± 2.6° (non-DDH/ mild DDH), and the anteversion differences were 4.7 ± 3.4° (severe DDH) and 2.3 ± 2.1° (non-DDH/ mild DDH). The anteversion difference was different between the two groups. Multivariate analysis showed that the navigation difference (absolute difference in anteversion between postoperative CT and navigation records of > 5°) was significantly associated with severe DDH (odds ratio [OR]: 3.3; p = 0.049, 95% confidence interval [CI]: 1.0-11.1) and posterior pelvic tilt (OR: 1.1; p = 0.042, 95% CI: 1.0-1.27). CONCLUSIONS: In patients with severe DDH, it is important to pay close attention during THA using portable navigation. However, the average difference was < 5º even in patients with severe DDH, and the accuracy may be acceptable in a clinical setting when the cost is considered.

[Correlation between femoral offset, rotation center and leg length discrepancy after total hip arthroplasty based on digital analysis].

OBJECTIVE: CT scans combined with Mimics software were used to measure femoral offset (FO), rotation center height (RCH) and lower leg length discrepancy (LLD) following total hip arthroplasty (THA), and the relationship between FO, RCH and LLD after THA is discussed. METHODS: Retrospective analysis was performed on 40 patients with unilateral THA who met standard cases from October 2020 to June 2022. There were 21 males and 19 females, 18 patients on the left side and 22 patients on the right side, aged range from 30 to 81 years old, with an average age of (58.90 ±14.13) years old, BMI ranged from 17.3 to 31.5 kg·m-2 with an average of (25.3±3.4) kg·m-2. There were 30 cases of femoral head necrosis (Ficat type Ⅳ), 2 cases of hip osteoarthritis (Tönnis type Ⅲ), 2 cases of developmental hip dislocation combined with end-stage osteoarthritis (Crowe type Ⅲ), and 6 cases of femoral neck fracture (Garden type Ⅳ). Three-dimensional CT reconstruction of pelvis was taken preoperative and postoperative, and three-dimensional reconstruction model was established after processing by Mimics software. FO, RCH and LLD were measured on the model. The criteria for FO reconstruction were as follows:postoperative bilateral FO difference less than 5 mm;the standard for equal length of both lower limbs was as follows:postoperative LLD difference less than 5 mm. RESULTS: Bilateral FO difference was positively correlated with LLD (r=0.744, P<0.001). Chi-square test was performed between the FO reconstructed group and the non-reconstructed eccentricity group:The results showed that the isometric ratio of lower limbs in the FO reconstructed group was significantly higher than that in the FO reconstructed group (χ2=6.320, P=0.012). The bilateral RCH difference was significantly negatively correlated with LLD(r=-0.877, P<0.001). There is a linear relationship between bilateral FO difference and bilateral RCH difference and postoperative LLD, and the linear regression equation is satisfied:postoperative LLD=0.038x-0.099y+0.257(x:postoperative bilateral FO difference, y:postoperative bilateral RCH difference; Unit:cm), F=77.993, R2=0.808, P=0.009. CONCLUSION: After THA, LLD increased with the increase of FO and decreased with the increase of RCH. The effect of lower limb isometric length can be obtained more easily by reconstruction of FO. There is a linear relationship between the bilateral FO difference and the bilateral RCH difference after THA and LLD, and the regression equation can provide a theoretical reference for judging LLD.

15-year survivorship of a unique dual-modular femoral stem in primary hip arthroplasty.

BACKGROUND: Hip offset, version, and length are interdependent femoral variables which determine stability and leg length. Balancing these competing variables remains a core challenge in hip arthroplasty. The potential benefits of modular femoral stems have been overshadowed by higher rates of failure. The objective of this study was to assess the survivorship of a unique dual-modular femoral stem at an average 15-year follow-up period. METHODS: The records of all patients with osteoarthritis who underwent primary total hip arthroplasty with this device between 2004-2009 were reviewed. There were no exclusions for BMI or other factors. We examined the data with Kaplan-Meier survival analysis. The primary endpoint for survival was mechanical failure of the modular neck-body junction. RESULTS: The survivorship of this device in 172 subjects was 100% with none experiencing mechanical failure of the modular junction at an average of 15 years. 60 patients died of causes unrelated to their THA and 9 patients were lost to follow-up. There were three early (≤ 12 months) dislocations (1.7%), and seven total dislocations (4.1%). 16 patients underwent reoperations during the follow-up period, none for any complication of the modular junction. Radiographic results showed well-fixed femoral stems in all cases. There were no leg length discrepancies of greater than 10 mm, and 85% were within 5 mm. CONCLUSION: There were no mechanical failures of the modular junction in any of the subjects over the average 15-year period, demonstrating that this dual-modular design is not associated with increased failure rates. We achieved a 1.7% early dislocation rate and a 4.1% total dislocation rate without any clinically significant leg length discrepancies.

Efficacy of local infiltration analgesia on recovery after total hip arthroplasty using direct anterior approach under spinal anaesthesia: a randomized, double-blind, placebo-controlled trial.

The utilization of local infiltration analgesia (LIA) is a common practice in total hip arthroplasty (THA) procedures to mitigate postoperative pain and diminish the necessity for opioids. However, contemporary literature reports conflicting results. Our working hypothesis was that LIA renders better postoperative VAS-scores and reduces the need for oral analgetics. We performed a randomized, double-blind, placebo-controlled trial aimed at examining the effectiveness of LIA in THA. A total of 90 patients were included for statistical analysis. Our primary endpoint was the Visual Analogue Scale, VAS, (0: no pain, 10: unbearable pain) preoperatively, at the 1st, 2nd, 3rd, 4th and 12th hour postoperative intervals and at discharge. Our secondary endpoints included the postoperative opioid consumption, as well as patient satisfaction at 2 and 6 weeks postoperatively, measured using the Numeric Rating Scale, NRS. LIA has a tendency for superior results regarding VAS- Scores at 3 and 4 hours postoperatively. There were no notable statistical distinctions observed in terms of patients necessitating rescue opioid consumption. Patient satisfaction using the NRS at both the 2-week and 6-week postoperatively did not differ significantly between both groups. The administration of LIA could offer advantages during the initial stages of postoperative recovery, which could be particularly valuable in rapid recovery programs.

Excellent survival of two anatomically adapted hydroxyapatite coated cementless Total Hip Arthroplasties. A mean follow-up of 11.3 years.

There are many different types of cementless anatomically adapted Total Hip Arthroplasties (THAs) on the market, the Anatomic Benoist Gerard (ABG) I and II are such types of cementless THAs. In this retrospective single-centre study we evaluated the overall survival with revision for any reason and aseptic loosening as endpoint at more than 11 years follow-up. Between 2000 and 2004, 244 cementless THAs were performed in 230 patients in a primary care hospital. At a mean of 11.3 years follow-up (range 9.8 - 12.8 years) clinical examination, plain radiography and Patient Reported Outcome Measures (PROMs) were obtained and analysed. The PROMs consisted of the Oxford Hip Score (OHS) and the Western Ontario and McMaster University Index (WOMAC). At a mean of 11.3 years follow-up 32 patients (13.1%) had died of unrelated causes. Of the remaining cohort all 198 patients (212 THAs) have been reached for evaluation. There were no patients considered as lost to follow-up. At a mean of 11.3 years 11 patients (11 THAs) have had a revision of either the femoral implant or acetabular component resulting in an overall survival of 95.5%. There was no statistically significant difference (p=0.564) in survival between the ABG I and II THAs. Radiographic there were no changes between the ABG I and II last follow up. The ABG II performed statistically significant better in PROMs. We concluded that both anatomically adapted hydroxyapatite coated cementless THAs show excellent survival at more than 11 years follow-up.

Clinical, functional and radiographic long-term follow-up (7-12 years) of Birmingham Hip Resurfacing, including metal ions evaluation: a single surgeon series.

Hip resurfacing arthroplasty (HRA) has been advocated as an attractive therapy for a younger, more demanding patient population with debilitating hip osteoarthritis. Controversies surrounding metal-on-metal (MoM) hip resurfacing have, however, led to a significant decline in the popularity of the HRA. Despite this, substantial evidence supports the use of specific implants in a selected group of patients. This is a continued retrospective analysis of a single surgeon series of the Birmingham Hip Resurfacing (BHR). Initial medium-term analysis was done in 2011 and published by Van der Bracht et al.13. This analysis includes a long-term follow-up of 7 to 12 years, including functional scoring (HHS, HOOS and UCLA activity score), metal ion evaluation and survival analysis. Failure was defined as revision for any cause. A total of 267 resurfacing procedures with the BHR were included in 247 patients. We had a mean follow-up of 8.3 years. Overall survival at ten years was 94.8%(97.2% for males and 90.1% for females). There was a statistically significant increase in mean HHS score at follow-up (56.03 - IQR 47-65 to 96.07 - IQR 96-100). Elevated metal ions were correlated with a statistically significant increase in the probability of complications. This cohort study further proved that hip resurfacing arthroplasty with the Birmingham Hip Resurfacing implant provides a good alternative to conventional total hip arthroplasty in young patients. There was a significant increase in functional scores at follow-up. There is further evidence of less favorable outcomes in female patients.