BACKGROUND: In the treatment of chronic prosthetic joint infection (PJI) of the hip, two-stage exchange arthroplasty is commonly employed. Various spacer designs, including Hemi-Spacers and Articulating Spacers, are utilized during this process. However, these spacers are associated with a high rate of mechanical complications and pose a risk of progressive bone loss. This study aims to compare these two types of spacers in terms of mechanical complications, center of rotation (COR) restoration, and preservation of acetabular bone stock.
METHODS: From 2019 to 2022, patients who underwent two-stage exchange arthroplasty for hip PJI across three hospitals were retrospectively reviewed. Data including demographic, clinical, and microbiological information were collected. Radiographic imaging was analyzed to measure acetabular bone erosion, COR, and periacetabular bone resected. Additionally, the average surgical time in the first and second stages, mechanical complications, and the mean duration of the inter-stage period were recorded.
RESULTS: Forty patients were divided into two groups: Group A (Articulating Spacer, n = 23) received a preformed femur spacer with acetabular cement augmentation, while Group B (Hemi-Spacer, n = 17) received a preformed femur spacer alone. Acetabular cement augmentation slightly prolonged the first stage but facilitated a faster second stage during subsequent reimplantation. Spacer dislocation rates were 8.7% in Group A and 17.6% in Group B during the interstage period. Radiographic analysis revealed a statistically significant greater degree of acetabular erosion in Group B. A significant difference in Vertical-COR differential was observed, with a more proximalized revision cup compared to the primary cup in Group B, and Horizontal-COR values closer to the native hip in Group A.
CONCLUSIONS: Dynamic spacers with acetabular cement augmentation help preserve peri-acetabular bone stock and prevent progression of acetabular bone erosion during the inter-stage period. Additionally, these spacers reduce the dislocation rates, making reimplantation easier and leading to better restoration of hip biomechanics during the second procedure.

OBJECTIVE: The aim of this study was to assess the inter-rater reproducibility and inter-method comparability of hip alpha angle measurements on magnetic resonance imaging (MRI)/magnetic resonance arthrography (MRA) and plain radiographs in patients with femoroacetabular impingement syndrome (FAIS).
METHODS: A cross-sectional study of patients who were diagnosed with symptomatic FAIS underwent preoperative MRI/MRA with axial oblique and/or radial plane imaging and had preoperative radiographs with anterior-posterior (AP), 45° Dunn and 90° Dunn views. Alpha angle measurements were performed independently by two musculoskeletal radiologists. Inter-rater reproducibility and inter-method comparability between MRI/MRA images and radiographic views were assessed using the intraclass correlation coefficient (ICC) with 95% confidence interval (CI).
RESULTS: Ninety-seven patients were included of whom 93 (95.8%) received axial oblique plane images and 54 (55.6%) had radial plane MRI/MRA images. Inter-rater reproducibility was excellent (ICC > 0.9) for all planes on MRI/MRA and radiographs. MRI/MRA axial oblique images had poor (ICC 0.39, 95% CI [0.09, 0.59]), moderate (ICC 0.57, 95% CI [0.18, 0.75]) and moderate (ICC 0.64, 95% CI [0.20, 0.81]) comparability with AP, 45° Dunn and 90° Dunn, respectively. MRI/MRA radial plane images had equivocal (0 included in all CIs) comparability with AP (ICC 0.66), 45° Dunn (ICC 0.35) and 90° Dunn (ICC 0.14) radiographs. On average, alpha angle measurements were significantly higher with radial images and lower with axial oblique images, when compared to all radiographic views (p < 0.05), except axial oblique versus 45° Dunn views, where angles measured on axial oblique were significantly larger.
CONCLUSIONS: Alpha angle measurements taken on axial oblique MRI/MRA images show moderate comparability to radiographic 45° Dunn and 90° Dunn views despite negative bias to measurements taken on radiographic AP and 45° Dunn view. Larger alpha angles were appreciated on MRI/MRA radial and axial oblique views compared to radiographic views supporting the inclusion of MRI/MRA alpha angle measurements to properly identify deformity.
METHODS: Level II.

The present Bayesian network meta-analysis compared different types of polyethylene liners in total hip arthroplasty (THA) in terms of wear penetration (mm/year) and rate of revision. The type of liners compared were the crosslinked ultra-high molecular weight polyethylene (CPE/UHMWPE), Vitamin E infused highly cross-linked polyethylene (HXLPE-VEPE), modified cross-linked polyethylene (MXLPE), highly cross-linked polyethylene (HXLPE), Cross-linked polyethylene (XLPE). This study was conducted according to the PRISMA extension statement for reporting systematic reviews incorporating network meta-analyses of healthcare interventions. In June 2024, PubMed, Scopus, Embase, Google Scholar, and Cochrane databases were accessed. A time constraint was set from January 2000. All investigations which compared two or more types of polyethylene liners for THA were accessed. Only studies that clearly stated the nature of the liner were included. Data from 60 studies (37,352 THAs) were collected. 56% of patients were women. The mean age of patients was 60.0 ± 6.6 years, the mean BMI was 27.5 ± 2.0 kg/m2. The mean length of follow-up was 81.6 ± 44.4 months. Comparability was found at baseline between groups. XLPE and HXLPE liners in THA are associated with the lowest wear penetration (mm/year) and the lowest revision rate at approximately 7 years of follow-up.

BACKGROUND: Hip osteoarthritis (OA) is a prevalent and debilitating condition, necessitating effective and safe treatment options. This systematic review aims to explore the potential of intra-articular mesenchymal stem cell (MSC) infiltrations as a therapeutic approach for hip OA.
METHODS: Following PRISMA guidelines, a systematic review was conducted, encompassing PubMed, Embase, and Cochrane Library databases. Inclusion criteria involved studies focusing on intra-articular MSC injections in patients with hip OA and reporting pain relief as an outcome measure. Quality assessment utilized the Newcastle-Ottawa scale and methodological index for non-randomized studies.
RESULTS: Ten studies were included in the review, exhibiting varied designs and sample sizes (316 patients). Outcome measures consisted of cartilage repair assessed through MRI and radiographies, pain scores (WOMAC, VAS, NRS), and functional improvements (HOS-ADL, OHS, FRI, PDQQ, LEFS). The studies reported favorable improvements in functional scores, pain relief, and cartilage repair/radiographic findings, with minimal reported adverse events.
CONCLUSIONS: Intra-articular MSC infiltrations demonstrate promise as an effective and safe therapeutic intervention for managing hip OA, offering pain relief and functional enhancements. Nevertheless, limited high-quality studies and outcome measure variations underscore the need for further research to establish definitive treatment guidelines. Future investigations should address optimal MSC utilization, long-term outcomes, and potential complications to ensure the success of MSC-based therapies for hip OA management, ultimately improving patient outcomes. The findings provide valuable insights into the potential of MSC-based treatments for hip OA, advocating further rigorous research in this field.
BACKGROUND: The protocol was registered on PROSPERO database (CRD42023436973).

OBJECTIVE: Hip arthroscopy is effective in treating bordline developmental dysplasia of the hip (BDDH), but there are only a few clinical reports in China, and its postoperative failure rate is still a problem that cannot be ignored. The aim of this study was to analyze the clinical effect of hip arthroscopy in BDDH treatment in China and to explore the risk factors influencing the efficacy of hip arthroscopy in BDDH treatment.
METHODS: All of 22 cases of BDDH treated with arthroscopy in our hospital from November March 2017 to February 2022 were analyzed retrospectively, including ten males and 12 females, with an average age of 34.7 ± 9.5 years (19-53 years). All patients underwent arthroscopic treatment with acetabular plasty, labral repair, femoral osteoplasty, and capsular plication. Visual Analogue Scale (VAS), modified Harris Hip Scores (mHHS), Hip Outcome Score-activities of Daily Living (HOS-ADL) and International Hip Outcome Tool-12 (iHOT-12) were measured before operation and at the follow-up, and statistical analysis was performed. The Minimum clinically significant difference (MCID) and Patient Acceptable Symptom State (PASS) were also obtained.
RESULTS: 22 patients were followed up, and the follow-up time was ≥ one year, with an average of 21.4 ± 8.2 months. The VAS score decreased from 5.27 ± 1.58 points before surgery to 1.96 ± 0.92 points at the follow-up, and the difference was statistically significant (t = 9.05,P < 0.001). The mHHS score increased from 64.84 ± 13.58 points before surgery to 90.4 ± 10.11 points at the follow-up, and the difference was statistically significant (t=-7.07, P < 0.001). The HOS-ADL score increased from 68.92 ± 11.76 points before surgery to 88.91 ± 9.51 points at the follow-up, and the difference was statistically significant (t=-8.15,P < 0.001). The iHOT-12 score increased from 49.32 ± 12.01 points before surgery to 79.61 ± 15.89 points at the follow-up, and the difference was statistically significant (t=-7.66,P < 0.001). The MCID (mHHS) and MCID (HOS-ADL) were 81.8% and 77.3% respectively, and the PASS (mHHS) and PASS (HOS-ADL) were 86.4% and 72.7% respectively at the follow-up.
CONCLUSIONS: Hip arthroscopy can achieve good short-term outcomes in the treatment of BDDH.
METHODS: IV Therapeutic Study.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a critical orthopedic condition ranging from minor hip joint instability to complete dislocations, demanding early intervention to avoid severe complications, especially in children. In Mexico, stringent regulations under the Norma Oficial Mexicana (NOM) mandate hip screening for pediatric patients. The primary objective of this study is to investigate the relationship between alpha angles and the acetabular index in patients at six months of age, aiming to determine whether an increase in the alpha angle correlates with a better acetabular index.
METHODS: We included 120 patients who were screened for hip issues with Graf\'s methodology in June 2023 and September 2023 at the General Hospital of Mexico \"Dr. Eduardo Liceaga\" in Mexico City before three months of age and attended their follow-up appointment at six months of age, where acetabular index measurement was performed using the Carestream platform on institutional X-rays.
RESULTS: In our statistical analysis, we obtained a statistically significant relationship between an increase in the left hip alpha angle and a decrease in the left hip acetabular index (p=0.015) although it was not significant for an acetabular index of less than 25° (p=0.055). A significant relationship was observed between the right hip acetabular index and the right hip alpha angle (p=0.017) but not significant for an acetabular index less than 25° (p=0.10).
CONCLUSIONS: Universal hip screening is crucial for the early detection of DDH. Our study emphasizes using alpha-angle measurements (>70°) as reliable indicators of normal hip health.

The primary objective of this study was to develop a custom algorithm to assess three-dimensional (3D) acetabular coverage of the femoral head based on surface models generated from computed tomography (CT) imaging. The secondary objective was to apply this algorithm to asymptomatic young adult hip joints to assess the regional 3D acetabular coverage variability and understand how these novel 3D metrics relate to traditional two-dimensional (2D) radiographic measurements of coverage. The algorithm developed automatically identifies the lateral- and medial-most edges of the acetabular lunate at one-degree intervals around the acetabular rim based on local radius of curvature. The acetabular edges and the center of a best-fit sphere to the femoral head are then used to compute the mean 3D subchondral arc angles and hip joint coverage angles in five acetabular octants. This algorithm was applied to hip models generated from pelvis/hip CT imaging or abdomen/pelvis CT angiograms of 50 patients between 17 and 25 years of age who had no history of congenital or developmental hip pathology, neuromuscular conditions, or bilateral pelvic and/or femoral fractures. Corresponding 2D acetabular coverage measures of lateral center edge angle (LCEA) and acetabular arc angle (AAA) were assessed on the patients\' clinical or digitally reconstructed radiographs. The 3D subchondral arc angle in the superior region (58.0 [54.6-64.8] degrees) was significantly higher (p < 0.001) than all other acetabular subregions. The 3D hip joint coverage angle in the superior region (26.2 [20.7-28.5] degrees) was also significantly higher (p < 0.001) than all other acetabular subregions. 3D superior hip joint coverage angle demonstrated the strongest correlation with 2D LCEA (r = 0.649, p < 0.001), while 3D superior-anterior subchondral arc angle demonstrated the strongest correlation with 2D AAA (r = 0.718, p < 0.001). The 3D coverage metrics in the remaining acetabular regions did not strongly correlate with typical 2D radiographic measures. The discrepancy between standard 2D measures of radiographic acetabular coverage and actual 3D coverage identified on advanced imaging indicates potential discord between anatomic coverage and the standard clinical measures of coverage on 2D imaging. As 2D measurement of acetabular coverage is increasingly used to guide surgical decision-making to address acetabular deformities, this work would suggest that 3D measures of acetabular coverage may be important to help discriminate local coverage deficiencies, avoid inconsistencies resulting from differences in radiographic measurement techniques, and provide a better understanding of acetabular coverage in the hip joint, potentially altering surgical planning and guiding surgical technique.

BACKGROUND: Reinfection rates after two-stage revision (TSR) for prosthetic joint infection (PJI) range from 7.9 to 14%. Many factors, including sinus tracts, are associated with reinfection after this procedure. This study aimed to delineate whether the presence of sinus tract could increase reinfection rate after TSR and to investigate other potential risk factors for reinfection after TSR.
METHODS: We conducted a case-control study by retrospectively reviewing patients who underwent TSR for prosthetic hip joint infection from 2002 to 2022. The case group included patients who developed reinfection after TSR, while the control group consisted of patients who did not experience reinfection. PJI and reinfection after TSR were defined based on Delphi-based international consensus criteria. Patient demographics, past medical history, clinical manifestations, laboratory results, interval between stages, microbiological culture results were collected. Univariate analyses were utilized to assess the effect of sinus tract on reinfection and to identify other risk factors for reinfection after TSR.
RESULTS: Six patients with reinfection after TSR were included as the case group and 32 patients without reinfection were in the control group. Significant difference was observed in percentage of patients with sinus tracts between the two groups (67% in the case group versus 19% in the control group, p = 0.031, OR = 8.7). Significant difference was also found in percentage of patients with positive cultures of synovial fluid and synovium harvested during the first-stage revision between the two groups (100% in the case group versus 50% in the control group, p = 0.030). Additionally, patients in the case group had a significantly higher C-reactive protein (CRP) level prior to the second stage revision than that of patients in the control group (8.80 mg/L versus 2.36 mg/L, p = 0.005), despite normal CRP levels in all patients.
CONCLUSIONS: Our study revealed that the presence of sinus tracts could significantly increase risk of postoperative reinfection after TSR. Positive cultures during the first stage revision and elevated CRP level prior to the second stage revision could also increase the risk of reinfection after TSR. Further studies with a larger sample size are required.
BACKGROUND: Retrospectively registered.

UNASSIGNED: The aim of this study is to present a newly developed automated method to determine radiographic measurements of hip morphology on dual-energy x-ray absorptiometry (DXA) images. The secondary aim was to compare the performance of the automated and manual measurements.
UNASSIGNED: 30 DXA scans from 13-year-olds of the prospective population-based cohort study Generation R were randomly selected. The hip shape was outlined automatically using radiographic landmarks from which the acetabular depth-width ratio (ADR), acetabular index (AI), alpha angle (AA), Wiberg and lateral center edge angle (WCEA) (LCEA), extrusion index (EI), neck-shaft angle (NSA), and the triangular index (TI) were determined. Manual assessments were performed twice by two orthopedic surgeons. The agreement within and between observers and methods was visualized using Bland-Altman plots, and the reliability was studied using the intraclass correlation coefficient (ICC) with 95 % confidence intervals (CI).
UNASSIGNED: The automated method was able to perform all radiographic hip morphology measurements. The intermethod reliability between the automated and manual measurements ranged from 0.57 to 0.96 and was comparable to or better than the manual interobserver reliability, except for the AI.
UNASSIGNED: This open-access, automated method allows fast and reproducible calculation of radiographic measurements of hip morphology on right hip DXA images. It is a promising tool for performing automated radiographic measurements of hip morphology in large population studies and clinical practice.

UNASSIGNED: Bone marrow aspirate (BMA) intra-articular injection is a minimally invasive orthobiologic treatment option for osteoarthritis (OA). Hip OA affects a significant portion of the population and has a paucity of data surrounding orthobiologic treatments. The primary objective of this study was to delineate the clinical impact of bone marrow aspirate intra-articular injections on decreasing pain and improving function in patients with hip OA.
UNASSIGNED: A single-center, retrospective analysis of thirty-one patients, aged 32 to 83 (62.4 ​± ​16.5), with Kellgren-Lawrence (KL) Hip OA grading of 2-4 (mean 2.9 ​± ​0.7), who underwent intra-articular bone marrow aspirate injection into the hip and were followed for twelve months. Evaluation was at baseline, 12 weeks, 6 months, and 12 months using the Numerical Rating Scale (NRS) for pain and the Hip Disability and Osteoarthritis Outcome Score Jr (HOOS-Jr) for function. The proportion of responders, as defined by a ≥50% reduction in NRS pain score, was assessed at 12 weeks, 6 months and 12 months.
UNASSIGNED: At 6 and 12 months follow-up, there was a statistically significant improvement in NRS scores (P ​< ​0.05). Stratifying by KL grade, subjects with KL grades 2 and 3 experienced statistically significant improvement in NRS scores at 6 and 12 months. Patients with KL grade 4 showed significant improvement in pain at 12 months. Forty-two percent of patients at 6 months and 61% at 12 months reported ≥50% reduction in pain. When stratifying by KL grade, 80% and 71% of KL2 and KL3 grades respectively were responders by 12 months. Patients experienced statistically significant improvement in HOOS-Jr scores at 6 and 12 months.
UNASSIGNED: In patient with mild, moderate, and severe hip OA, BMA may be an alternative treatment that improves pain and function in patients for as long as 12 months. In addition, BMA may also be an effective, lower cost option to more expensive BMAC preparations.