An in-depth analysis of young adults with osteonecrosis secondary to developmental dysplasia of the hip who underwent total hip arthroplasty.

BACKGROUND: Patients with osteonecrosis of the femoral head secondary to DDH frequently require total hip arthroplasty (THA), but it is not well understood which factors necessitate this requirement. We determined the incidence of THA in patients who have osteonecrosis secondary to DDH and factors associated with need for THA. METHODS: We included patients who received closed or open reductions between 1995 and 2005 with subsequent development of osteonecrosis. We determined osteonecrosis according to Bucholz and Ogden; osteoarthritis severity (Kellgren-Lawrence), subluxation (Shenton's line); neck-shaft angle; and acetabular dysplasia (centre-edge and Sharp angles). We also recorded the number of operations of the hip in childhood and reviewed case notes of patients who received THA to describe clinical findings prior to THA. We assessed the association between radiographic variables and the need for THA using univariate logistic regression. RESULTS: Of 140 patients (169 hips), 22 patients received 24 THA (14%) at a mean age of 21.3 ± 3.7 years. Associated with the need for THA were grade III osteonecrosis (OR 4.25; 95% CI 1.70-10.77; p = 0.0019), grade IV osteoarthritis (21.8; 7.55-68.11; p < 0.0001) and subluxation (8.22; 2.91-29.53; p = 0.0003). All patients who required THA reported at least 2 of: severe pain including at night, stiffness, and reduced mobility. Acetabular dysplasia and number of previous operations were not associated with the need for THA. CONCLUSIONS: We identified a 14% incidence of THA by age 34 years in patients with osteonecrosis secondary to DDH. Grade III osteonecrosis (global involvement femoral head and neck) was strongly associated with THA, emphasising the importance to avoid osteonecrosis when treating DDH.

Clinical efficacy of multiple intra-articular injection for hip osteoarthritis.

Aims: Intra-articular (IA) injection may be used when treating hip osteoarthritis (OA). Common injections include steroids, hyaluronic acid (HA), local anaesthetic, and platelet-rich plasma (PRP). Network meta-analysis allows for comparisons between two or more treatment groups and uses direct and indirect comparisons between interventions. This network meta-analysis aims to compare the efficacy of various IA injections used in the management of hip OA with a follow-up of up to six months. Methods: This systematic review and network meta-analysis used a Bayesian random-effects model to evaluate the direct and indirect comparisons among all treatment options. PubMed, Web of Science, Clinicaltrial.gov, EMBASE, MEDLINE, and the Cochrane Library were searched from inception to February 2023. Randomized controlled trials (RCTs) which evaluate the efficacy of HA, PRP, local anaesthetic, steroid, steroid+anaesthetic, HA+PRP, and physiological saline injection as a placebo, for patients with hip OA were included. Results: In this meta-analysis of 16 RCTs with a total of 1,735 participants, steroid injection was found to be significantly more effective than placebo injection on reported pain at three months, but no significant difference was observed at six months. Furthermore, steroid injection was considerably more effective than placebo injection for functional outcomes at three months, while the combination of HA+PRP injection was substantially more effective at six months. Conclusion: Evidence suggests that steroid injection is more effective than saline injection for the treatment of hip joint pain, and restoration of functional outcomes.

Bilateral simultaneous hip and knee replacement: an epidemiological nationwide study from 2001 to 2016.

BACKGROUND: Several studies have compared the pros and cons of simultaneous bilateral versus staged bilateral hip and knee replacement but the outcomes of these two surgical options remains a matter of controversy. This study aimed to evaluate demographic features, incidence and hospitalization rates of bilateral one stage total hip and knee arthroplasty in Italy. METHODS: The Italian Ministry of Health's National Hospital Discharge Reports (SDO) were used to gather data. This study referred to the adult population (+ 20 years of age) from 2001 to 2015 for hip arthroplasty and from 2001 to 2016 for knee arthroplasty. RESULTS: Overall, 1,544 bilateral simultaneous hip replacement were carried out. The incidence rate was 0.21 cases per 100,000 adult Italian residents. Male/female ratio was 1.1. The average days of hospital stay was 11.7 ± 11.8 days. The main primary codified diagnosis was: osteoarthrosis, localized, primary, pelvic region and thigh (ICD code: 715.15). 2,851 bilateral simultaneous knee replacement were carried out. The incidence rate was 0.37 cases per 100,000 adult Italian residents. Male/female ratio was 0.6. The average days of hospital stay was 7.7 ± 5.8 days. The main primary codified diagnosis was: osteoarthrosis, localized, primary, lower leg (ICD code: 715.16). CONCLUSIONS: The burden of hip and knee osteoarthrosis as a leading cause of bilateral joint replacement is significant in Italy. The national registers' longitudinal analysis may provide data for establishing international guidelines regarding the appropriate indications for one stage bilateral simultaneous hip or knee replacement versus two stage.

A Prospective Randomized Controlled Trial Assessing the Impact of Preoperative Combined with Postoperative Progressive Resistance Training on Muscle Strength, Gait, Balance and Function in Patients Undergoing Total Hip Arthroplasty.

Purpose: The aim of this study is to investigate the effects of a preoperative combined with postoperative moderate-intensity progressive resistance training (PRT) of the operative side in patients with hip osteoarthritis (HOA) who are undergoing total hip arthroplasty (THA). The study seeks to evaluate the impact of this combined intervention on muscle strength, gait, balance, and hip joint function in a controlled, measurable, and objective manner. Additionally, the study aims to compare the outcomes of this combined intervention with those of preoperative or postoperative muscle strength training conducted in isolation. Methods: A total of 90 patients with HOA scheduled for unilateral primary THA were randomly assigned to three groups: Pre group (preoperative PRT), Post group (postoperative PRT), and Pre& Post group (preoperative combined with postoperative PRT) focusing on hip flexion, extension, adduction, and abduction of operated side. Muscle strength, gait parameters, balance, and hip function were assessed at specific time points during a 12-month follow-up period. Results: All three groups showed significant improvements in muscle strength, with the Pre& Post group demonstrating the most pronounced and sustained gains. Gait velocity and cadence were significantly improved in the Pre& Post group at 1-month and 3-month postoperative follow-ups compared to the other groups. Similarly, the Pre& Post group exhibited superior balance performance at 3-month and 12-month postoperative follow-ups. The Harris Hip Score also showed better outcomes in the Pre& Post group at all follow-up intervals. Conclusion: Preoperative combined with postoperative moderate-intensity PRT in HOA patients undergoing THA led to superior improvements in muscle strength, gait, balance, and hip joint function compared to preoperative or postoperative PRT alone. This intervention shows significant promise in optimizing postoperative rehabilitation and enhancing patient outcomes following THA.

The social and organisational factors shaping acceptability of a self-management education and exercise intervention for people with hip or knee osteoarthritis in Greenland.

This study aimed to explore the experiences and perspectives of people with osteoarthritis attending the "Osteoarthritis School" (OA School) in Nuuk, Greenland to generate insights and lessons that can inform the development of self-management education and exercise interventions for people with other lifestyle conditions in a Greenland context. We conducted a qualitative interpretive description (ID) study based on ten semi-structured interviews with people with hip or knee osteoarthritis. Interviews were audio-recorded, transcribed, and coded. Using ID, we identified three themes: 1) perceptions and experiences of how the OA School intervention was organised (time and place); 2) perspectives and experiences of the education and exercise components (social factors, motivation, and education); and 3) significant change stories (physical and mental improvements and increased knowledge of OA). Social and organisational factors, such as working out with peers and the time and place of the intervention, influenced the participants' acceptance of the OA School intervention. Knowledge from this study will help us gain insight into what to address when developing future self-management education and exercise interventions in the Greenlandic healthcare system.

The impact of diabetes status on pain and physical function following total joint arthroplasty for hip and knee osteoarthritis: variation by sex and body mass index.

Few studies have examined diabetes impact on total joint arthroplasty (TJA) outcomes, with variable findings. We investigated the association between diabetes and post-TJA physical function and pain, examining whether diabetes impact differs by sex and BMI. Patient sample completed questionnaires within 3 months prior to hip or knee TJA for osteoarthritis (OA) and 1-year post-surgery. Surgical 'non-response' was defined as < 30% improvement in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and physical function at 1-year. Two adjusted logistic regression models were estimated: (1) excluding, (2) including an interaction between diabetes, sex and BMI. The sample (626 hip, 754 knee) was 54.9% female, had mean BMI of 30.1, 13.0% reported diabetes. In adjusted models excluding an interaction, diabetes was not associated with non-response. However, a significant 3-way interaction (physical function: p = 0.003; pain: p = 0.006) between diabetes, sex, and BMI was found and was associated with non-response: non-response probability increased with increasing BMI in men with diabetes, but decreased with increasing BMI in women in diabetes. Findings suggest uncertainty in diabetes impact may be due to differential impacts by sex and BMI. A simple consideration of diabetes as present vs. absent may not be sufficient, with implications for the large TJA population.

Difference in early all-cause mortality among patients having hip arthroplasty a Swedish perioperative registry study 2013-2022.

INTRODUCTION: Hip arthroplasty is a common orthopaedic procedure worldwide. There is an ongoing debate related to the fixation and anaesthesia impact on the 30-day mortality, particularly in the aging population with higher American Society of Anaesthesiology (ASA) Physical-Status. AIM: To study the 30-day all-cause mortality in patients undergoing primary hip arthroplasty, with regards to the impact of age, ASA-class, anaesthesia techniques, indication for surgery and fixation techniques. MATERIALS AND METHODS: Perioperative data for primary hip arthroplasty procedures for osteoarthritis and hip fractures registered in the Swedish Perioperative Registry (SPOR) between 2013 and June 2022 were collected. Binary logistic regressions were performed to assess the impact of age, ASA-class, anaesthetic technique, indication for surgery and fixation on odds ratio for 30-day mortality in Sweden. RESULTS: In total, 79,114 patients, 49,565 with osteoarthritis and 29,549 with hip fractures were included in the main study cohort. Mortality was significantly higher among hip fracture patients compared with osteoarthritis, cumulative 8.2% versus 0.1% at 30-days respectively (p < 0.001). Age above 80 years (OR3.7), ASA 3-5 (OR3.3) and surgery for hip fracture (OR 21.5) were associated with significantly higher odds ratio, while hybrid fixation was associated with a significantly lower odds ratio (OR0.4) of 30-day mortality. In the same model, for the subgroups of osteoarthritis and hip fracture, only age (OR 3.7) and ASA-class (OR 3.3) had significant impact, increasing the odds ratio for 30-day mortality. Hemi arthroplasty was commonly used among the hip fracture patients 20.453 (69.2%), and associated with a significantly higher odds ratio for all-cause 30-day mortality as compared to total hip arthroplasty when adjusting for age and ASA-class and fixation 2.3 (95%CI 1.9-2.3, p < 0.001). CONCLUSIONS: All-cause 30-day mortality associated with arthroplasty differed significantly between the two cohorts, hip fracture, and osteoarthritis (8.2% and 0.1% respectively) and mortality expectedly increased with age and higher ASA-class. Anaesthetic method and cement-fixation did not impact the odds ratio for all-cause 30-day mortality after adjustment for age and ASA-class.

[Application of modified acetabular anteversion and inclination angles test system in patients undergoing total hip arthroplasty after lumbar fusion].

Objective: To investigate the accuracy and effectiveness of acetabular cup placement in total hip arthroplasty (THA) after lumbar fusion applying of modified acetabular anteversion and inclination angles test system. Methods: A clinical data of 45 patients undergoing THA for osteoarthritis between January 2018 and June 2023 was retrospectively analyzed. All patients had previously received lumbar fusion. The modified acetabular anteversion and inclination angle test system was used in 26 cases (observation group) and not used in 19 cases (control group) during THA. There was no significant difference in baseline data such as gender, age, body mass index, operative side, number of lumbar fusion segments, and preoperative Harris score between the two groups ( P>0.05). The position of acetabular prosthesis, hip function (Harris score), and incidence of complications were compared between the two groups. Results: In the observation group, all acetabular cups were in the safe zone (anteversion angle, 25°-30°) during operation, and 1 acetabular cup (3.85%) was not in the safe zone after operation. In the control group, 9 acetabular cups (47.37%) were not in the safe zone. The postoperative difference between the two groups was significant ( P<0.05). There was no significant difference between intra- and post-operative acetabular inclination angles in the observation group ( P>0.05), and the postoperative acetabular inclination angle was significantly smaller in the observation group than in the control group ( P<0.05). All incisions healed by first intention and no infection occurred. All patients were followed up 6 months. There was no significant difference in Harris score between the two groups at different time point ( P>0.05), and there were significant differences between different time points in the two groups ( P<0.05). No joint dislocation occurred in the observation group during follow-up, while dislocation occurred in 2 cases and femoral impingement syndrome occurred in 1 case of the control group. There was no significant difference in the incidence of complications between the two groups ( P>0.05). Conclusion: For THA patients with lumbar fusion, the ideal placement angle of the acetabular cup can be obtained by using the modified acetabular anteversion and inclination angles test system during operation.

Annual epidemiological and health insurance disease burden of hip osteoarthritis in Hungary based on nationwide data.

BACKGROUND: Health services utilization related to hip osteoarthritis imposes a significant burden on society and health care systems. Our aim was to analyse the epidemiological and health insurance disease burden of hip osteoarthritis in Hungary based on nationwide data. METHODS: Data were extracted from the nationwide financial database of the National Health Insurance Fund Administration (NHIFA) of Hungary for the year 2018. The analysed data included annual patient numbers, prevalence, and age-standardized prevalence per 100,000 population in outpatient care, health insurance costs calculated for age groups and sexes for all types of care. Patients with hip osteoarthritis were identified using code M16 of the International Classification of Diseases (ICD), 10th revision. Age-standardised prevalence rates were calculated using the European Standard Population 2013 (ESP2013). RESULTS: Based on patient numbers of outpatient care, the prevalence per 100,000 among males was 1,483.7 patients (1.5%), among females 2,905.5 (2.9%), in total 2,226.2 patients (2.2%). The age-standardised prevalence was 1,734.8 (1.7%) for males and 2,594.8 (2.6%) for females per 100,000 population, for a total of 2,237.6 (2.2%). The prevalence per 100,000 population was higher for women in all age groups. In age group 30-39, 40-49, 50-59, 60-69 and 70 + the overall prevalence was 0.2%, 0.8%, 2.7%, 5.0% and 7.7%, respectively, describing a continuously increasing trend. In 2018, the NHIFA spent 42.31 million EUR on the treatment of hip osteoarthritis. Hip osteoarthritis accounts for 1% of total nationwide health insurance expenditures. 36.8% of costs were attributed to the treatment of male patients, and 63.2% to female patients. Acute inpatient care, outpatient care and chronic and rehabilitation inpatient care were the main cost drivers, accounting for 62.7%, 14.6% and 8.2% of the total health care expenditure for men, and 51.0%, 20.0% and 11.2% for women, respectively. The average annual treatment cost per patient was 3,627 EUR for men and 4,194 EUR for women. CONCLUSIONS: The prevalence of hip osteoarthritis was 1.96 times higher (the age-standardised prevalence was 1.5 times higher) in women compared to men. Acute inpatient care was the major cost driver in the treatment of hip osteoarthritis. The average annual treatment cost per patient was 15.6% higher for women compared to men.

Distinctiveness of Femoral and Acetabular Mesenchymal Stem and Progenitor Populations in Patients with Primary and Secondary Hip Osteoarthritis Due to Developmental Dysplasia.

Primary hip osteoarthritis (pOA) develops without an apparent underlying reason, whereas secondary osteoarthritis arises due to a known cause, such as developmental dysplasia of the hips (DDH-OA). DDH-OA patients undergo total hip arthroplasty at a much younger age than pOA patients (50.58 vs. 65 years in this study). Recently, mesenchymal stem and progenitor cells (MSPCs) have been investigated for the treatment of osteoarthritis due to their immunomodulatory and regenerative potential. This study identified cells in subchondral bone expressing common MSPC markers (CD10, CD73, CD140b, CD146, CD164, CD271, GD2, PDPN) in vivo and compared the proportions of these populations in pOA vs. DDH-OA, further correlating them with clinical, demographic, and morphological characteristics. The differences in subchondral morphology and proportions of non-hematopoietic cells expressing MSPC markers were noted depending on OA type and skeletal location. Bone sclerosis was more prominent in the pOA acetabulum (Ac) in comparison to the DDH-OA Ac and in the pOA Ac compared to the pOA femoral head (Fh). Immunophenotyping indicated diagnosis-specific differences, such as a higher proportion of CD164+ cells and their subsets in DDH-OA, while pOA contained a significantly higher proportion of CD10+ and GD2+ cells and subsets, with CD271+ being marginally higher. Location-specific differences showed that CD271+ cells were more abundant in the Fh compared to the Ac in DDH-OA patients. Furthermore, immunohistochemical characterization of stromal bone-adjacent cells expressing MSPC markers (CD10, CD164, CD271, GD2) in the Ac and Fh compartments was performed. This research proved that immunophenotype profiles and morphological changes are both location- and disease-specific. Furthermore, it provided potentially effective targets for therapeutic strategies. Future research should analyze the differentiation potential of subsets identified in this study. After proper characterization, they can be selectively targeted, thus enhancing personalized medicine approaches in joint disease management.

Do sex, age, and comorbidities modify the association of socioeconomic status and opioid use after total hip arthroplasty?: a population-based study from the Danish Hip Arthroplasty Register.

BACKGROUND AND PURPOSE: We aimed to examine the association between socioeconomic status (SES) markers and opioid use after primary total hip arthroplasty (THA) due to osteoarthritis, and whether sex, age, or comorbidities modify any association. METHODS: Using Danish databases, we included 80,038 patients undergoing primary THA (2001-2018). We calculated prevalences and prevalence ratios (PRs with 95% confidence intervals [CIs]) of immediate post-THA opioid use (≥ 1 prescription within 1 month) and continued opioid use (≥ 1 prescription in 1-12 months) among immediate opioid users. Exposures were individual-based education, cohabitation, and wealth. RESULTS: The prevalence of immediate opioid use was ~45% in preoperative non-users and ~60% in preoperative users (≥ 1 opioid 0-6 months before THA). Among non-users, the prevalences and PRs of continued opioid use were: 28% for low vs. 21% for high education (PR 1.28, CI 1.20-1.37), 27% for living alone vs. 23% for cohabiting (PR 1.09, CI 1.04-1.15), and 30% for low vs. 20% for high wealth (PR 1.43, CI 1.35-1.51). Among users, prevalences were 67% for low vs. 55% for high education (1.22, CI 1.17-1.27), 68% for living alone vs. 60% for cohabiting (PR 1.10, CI 1.07-1.12), and 73% for low wealth vs. 54% for high wealth (PR 1.32, CI 1.28-1.36). Based on testing for interaction, sex, age, and comorbidity did not statistically significant modify the associations. Nevertheless, associations were stronger in younger patients for all SES markers (mainly for non-users). CONCLUSION: Markers of low SES were associated with a higher prevalence of continued post-THA opioid use. Age modified the magnitude of the associations, but it was not statistically significant.

Viscosupplementation with High Molecular Weight Hyaluronic Acid for Hip Osteoarthritis: a Systematic Review and Meta-Analysis of Randomised Control Trials of the Efficacy on Pain, Functional Disability, and the Occurrence of Adverse Events.

PURPOSE OF THE STUDY: Hip osteoarthritis (OA) has a prevalence of around 6.4% and is the second most commonly affected joint. This review aims to assess the clinical outcomes of intra-articular high molecular weight hyaluronic acid (HMWHA) in the management of hip osteoarthritis. MATERIAL AND METHODS: We conducted a comprehensive search across PubMed, Google Scholar, and the Cochrane Library for randomised trials investigating the effectiveness of high molecular weight hyaluronic acid (HMWHA) in the treatment of hip osteoarthritis. Quality and risk of bias assessments were performed using the Cochrane RoB2 tool. To synthesise the data, we utilised the Standardised Mean Difference (SMD) for assessing pain relief through the Visual Analogue Scale (VAS) and the Lequesne index (LI) for evaluating functional outcomes. Risk Ratio (RR) was calculated to assess the occurrence of complications. RESULTS: A total of four studies involving HMWHA and control groups were included. The standardised mean difference (SMD) for the Visual Analogue Scale (VAS) (SMD -0.056; 95% CI; -0.351, 0.239; p = 0.709) and the Lequesne index (SMD -0.114; 95% CI; -0.524, 0.296; p = 0.585) were not statistically significant. Analysis for complications demonstrated an overall relative risk ratio (RR) of 0.879 (95% CI; 0.527, 1.466; p = 0.622), and was not statistically significant. DISCUSSION AND CONCLUSIONS: Intra-articular HMWHA in hip OA can significantly reduce pain and improve functional recovery when compared with the condition before treatment. However, there is no significant difference between HMWHA, or saline, or other therapeutic treatments. Currently, available evidence indicates that intra-articular HMWHA in hip OA would not increase the risk of adverse events. KEY WORDS: hip osteoarthritis, hyaluronic acid, intra-articular, molecular weight, viscosupplementation.

Causal relationship between sarcopenia with osteoarthritis and the mediating role of obesity: a univariate, multivariate, two-step Mendelian randomization study.

BACKGROUND: Recent genetic evidence supports a causal role for sarcopenia in osteoarthritis, which may be mediated by the occurrence of obesity or changes in circulating inflammatory protein levels. Here, we leveraged publicly available genome-wide association study data to investigate the intrinsic causal relationship between sarcopenia, obesity, circulating inflammatory protein levels, and osteoarthritis. METHODS: In this study, we used Mendelian randomization analyses to explore the causal relationship between sarcopenia phenotypes (Appendicular lean mass [ALM], Low hand-grip strength [LHG], and usual walking pace [UWP]) and osteoarthritis (Knee osteoarthritis [KOA], and Hip osteoarthritis [HOA]). Univariable Mendelian randomization (UVMR) analyses were performed using the inverse variance weighted (IVW) method, MR-Egger, weighted median method, simple mode, and weighted mode, with the IVW method being the primary analytical technique. Subsequently, the independent causal effects of sarcopenia phenotype on osteoarthritis were investigated using multivariate Mendelian randomization (MVMR) analysis. To further explore the mechanisms involved, obesity and circulating inflammatory proteins were introduced as the mediator variables, and a two-step Mendelian randomization analysis was used to explore the mediating effects of obesity and circulating inflammatory proteins between ALM and KOA as well as the mediating proportions. RESULTS: UVMR analysis showed a causal relationship between ALM, LHG, UWP and KOA [(OR = 1.151, 95% CI: 1.087-1.218, P = 1.19 × 10-6, PFDR = 7.14 × 10-6) (OR = 1.215, 95% CI: 1.004-1.470; P = 0.046, PFDR = 0.055) (OR = 0.503, 95% CI: 0.292-0.867; P = 0.013, PFDR = 0.027)], and a causal relationship between ALM, UWP and HOA [(OR = 1.181, 95% CI: 1.103-1.265, P = 2.05 × 10-6, PFDR = 6.15 × 10-6) (OR = 0.438, 95% CI: 0.226-0.849, P = 0.014, PFDR = 0.022)]. In the MVMR analyses adjusting for confounders (body mass index, insomnia, sedentary behavior, and bone density), causal relationships were observed between ALM, LHG, UWP and KOA [(ALM: OR = 1.323, 95%CI: 1.224- 1.431, P = 2.07 × 10-12), (LHG: OR = 1.161, 95%CI: 1.044- 1.292, P = 0.006), (UWP: OR = 0.511, 95%CI: 0.290- 0.899, P = 0.020)], and between ALM and HOA (ALM: OR = 1.245, 95%CI: 1.149- 1.348, P = 7.65 × 10-8). In a two-step MR analysis, obesity was identified to play a potential mediating role in ALM and KOA (proportion mediated: 5.9%). CONCLUSIONS: The results of this study suggest that decreased appendicular lean mass, grip strength, and walking speed increase the risk of KOA and decreased appendicular lean mass increases the risk of HOA in patients with sarcopenia in a European population. Obesity plays a mediator role in the occurrence of KOA due to appendicular lean body mass reduction.

Patients with total hip arthroplasty were more physically active 9.6 years after surgery: a case-control study of 429 hip arthroplasty cases and 29,272 participants from a population-based health study.

BACKGROUND AND PURPOSE: Few studies report on long-term levels of physical activity after THA compared with a control population. This case-control study aimed to find the long-term habitual level of leisure-time physical activity after THA and compare it with a large control group. PATIENTS AND METHODS: A randomized sample of 856 patients, treated with primary THA, were identified from the Norwegian Arthroplasty Register. 429 (50%) responded to a questionnaire with a mean follow-up time of 9.6 years. We compared them with a control group of 29,272 (64%) from a population-based health study. Physical activity was measured with a questionnaire and categorized into groups according to the general recommendations for physical activity. RESULTS: 245 (63%) of the THA cases reported a level of leisure-time physical activity meeting the general recommendations, compared with 10,803 (39%) in the control group. The difference persisted at all ages (50-90 years). In sex, age, and BMI-adjusted regression models the chance of meeting the physical activity recommendations was higher in the THA group than in the control group (OR 2.9, 95% confidence interval 2.4-3.6). CONCLUSION: The majority of the patients with THA reported a level of leisure-time physical activity meeting the general recommendations for physical activity. THA patients were more physically active in their leisure time than a control group representing a normal population.

Burden evaluation and prediction of osteoarthritis and site-specific osteoarthritis coupled with attributable risk factors in China from 1990 to 2030.

OBJECTIVE: This study aimed to estimate and predict the burden of osteoarthritis (OA) and site-specific OA (hip, knee, hand, and others) from 1990 to 2030 and their attributable risk factors in China. METHOD: Data were obtained from the Global Burden of Diseases 2019. The burden was estimated by analyzing the trends of prevalence, incidence, and disability-adjusted life years (DALY). Population attributable risk (PAR) was calculated to assess the impact of high body mass index (BMI). The prediction from 2020 to 2030 was implemented by Bayesian age-period-cohort analysis. RESULTS: In China, prevalent cases, DALY, and incident cases of OA increased to 132.81 million, 4.72 million, and 10.68 million, respectively. Age-standardized rates (ASRs) of prevalence, DALYs, and incidence increased for OA and site-specific OA, especially for hip OA. Site-specific OA showed different susceptible peaking ages, and the burden for those over 50 years old became serious. Female preference existed in the trends for knee OA but not in those for hip, hand, and other OA. PARs of high BMI continued to increase, impacting knee OA more than hip OA and showing female preference. In the next decade, incident cases for OA and site-specific OA will continue to increase, despite that the ASR of OA incidence will decrease. CONCLUSIONS: OA and site-specific OA remain huge public health challenges in China. The burden of OA and site-specific OA is increasing, especially among people over 50 years old. Health education, exercise, and removing modifiable risk factors contribute to alleviate the growing burden. Key Points • In China, the burden of osteoarthritis and site-specific osteoarthritis (hip, knee, hand, and others) as well as the Risk Factor (high body mass index) increased greatly from 1990 to 2019. • It is estimated that incident cases for OA and site-specific OA will continue to increase, despite that the ASR of OA incidence will decrease.

Is There Safety Outside the "Safe Zone" in Total Hip Replacement? A Retrospective Observational Study.

Background and Objectives: The safe zone in total hip replacement was introduced many years ago. Its aim was to provide guidelines for orthopedic surgeons in order to avoid complications such as instability. With the growing interest in spinopelvic alignment, some new insights suggest that the safe zone is an obsolete concept. This study aims to show that, even outside the safe zone, the effect of total hip replacement can be satisfactory. This could be used as preliminary study for an analysis of a larger group. Materials and Methods: Fifty-nine consecutive patients with end-stage osteoarthritis treated by total hip replacement were enrolled into the study and divided into two groups: inside the safe zone and outside the safe zone. A physical examination during postoperative visits was performed; the range of movement was measured using a goniometer; and the HHS and VAS were taken to measure functional outcomes and pain, respectively. An analysis of the radiological outcomes was performed. Results: There was no significant difference in regard to changes in total offset, pain, HHS and other complications. There were no signs of instability among patients during the follow-up. Conclusions: The results of this study show that the "safe zone" is a more complicated term that was previously thought. A proper soft tissue balance and spinopelvic alignment could be factors that change the "safe zone" for each patient and make it more individual.

Birmingham Hip Resurfacing at 25 years.

Aims: The Birmingham Hip Resurfacing (BHR) was introduced in 1997 to address the needs of young active patients using a historically proven large-diameter metal-on-metal (MoM) bearing. A single designer surgeon's consecutive series of 130 patients (144 hips) was previously reported at five and ten years, reporting three and ten failures, respectively. The aim of this study was to extend the follow-up of this original cohort at 25 years. Methods: The study extends the reporting on the first consecutive 144 resurfacing procedures in 130 patients for all indications. All operations were undertaken between August 1997 and May 1998. The mean age at operation was 52.1 years (SD 9.93; 17 to 76), and included 37 female patients (28.5%). Failure was defined as revision of either component for any reason. Kaplan-Meier survival analysis was performed. Routine follow-up with serum metal ion levels, radiographs, and Oxford Hip Scores (OHSs) was undertaken. Results: Overall implant survival was 83.50% (95% confidence interval (CI) 0.79 to 0.90) at 25 years, and the number at risk was 79. Survival in male patients at 25 years was 89.5% (95% CI 0.83 to 0.96) compared to 66.9% for female patients (95% CI 0.51 to 0.83). Ten additional failures occurred in the period of ten to 25 years. These involved an adverse reaction to metal debris in four patients, a periprosthetic femoral neck fracture affecting five patients, and aseptic loosening in one patient. The median chromium levels were 49.50 nmol/l (interquartile range (IQR) 34 to 70), and the median cobalt serum levels were 42 nmol/l (IQR 24.50 to 71.25). The median OHS at last follow-up was 35 (IQR 10 to 48). During the 25-year study period, 29 patients died. Patient survival at 25 years was 75.10% (95% CI 0.67 to 0.83). Conclusion: This study demonstrates that MoM hip resurfacing using the BHR provides a durable alternative to total hip arthroplasty (THA), particularly in younger male patients with osteoarthritis wishing to maintain a high level of function. These results compare favourably to the best results for THAs.

Fluoroscopy-guided triple hip block for patients with hip osteoarthritis: A new approach.

Hip osteoarthritis (OA) is found in approximately 10% of the population and often causes disability and social limitations in elderly patients. Intra-articular injections are among the most frequently applied interventional treatments for the hip joint. Femoral and obturator sensorial nerve blocks have also been reported to be effective for both diagnostic and therapeutic purposes. A single needle insertion was performed for the blockage of the hip joint and sensory branches. For the sensory branch of the femoral nerve, the needle is advanced at nearly a 45-degree angle toward below the anterior inferior iliac spine near the anterolateral edge of the hip joint. For the sensory branch of the obturator nerve, the needle is advanced at nearly an angle of 45 degrees toward the area below the junction of the pubis and ischium. Finally, for joint injection, the same needle was advanced toward the midline of the anterior femoral head-neck junction at a steeper angle, and blocks were applied. Three patients with hip osteoarthritis were injected with this method and well-being was achieved in a 3-month follow-up. We think that blockage of the hip joint and peripheral sensory branches with a single needle insertion is a fast and effective method. However, prospective controlled studies are needed to determine the efficacy and safety of the method.

[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.

Cohort profile: Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) - an international consortium of prospective cohort studies with individual participant data on hip osteoarthritis.

PURPOSE: Hip osteoarthritis (OA) is a major cause of pain and disability worldwide. Lack of effective therapies may reflect poor knowledge on its aetiology and risk factors, and result in the management of end-stage hip OA with costly joint replacement. The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium was established to pool and harmonise individual participant data from prospective cohort studies. The consortium aims to better understand determinants and risk factors for the development and progression of hip OA, to optimise and automate methods for (imaging) analysis, and to develop a personalised prediction model for hip OA. PARTICIPANTS: World COACH aimed to include participants of prospective cohort studies with ≥200 participants, that have hip imaging data available from at least 2 time points at least 4 years apart. All individual participant data, including clinical data, imaging (data), biochemical markers, questionnaires and genetic data, were collected and pooled into a single, individual-level database. FINDINGS TO DATE: World COACH currently consists of 9 cohorts, with 38 021 participants aged 18-80 years at baseline. Overall, 71% of the participants were women and mean baseline age was 65.3±8.6 years. Over 34 000 participants had baseline pelvic radiographs available, and over 22 000 had an additional pelvic radiograph after 8-12 years of follow-up. Even longer radiographic follow-up (15-25 years) is available for over 6000 of these participants. FUTURE PLANS: The World COACH consortium offers unique opportunities for studies on the relationship between determinants/risk factors and the development or progression of hip OA, by using harmonised data on clinical findings, imaging, biomarkers, genetics and lifestyle. This provides a unique opportunity to develop a personalised hip OA risk prediction model and to optimise methods for imaging analysis of the hip.