Artificial Intelligence-Guided Assessment of Femoral Neck Fractures in Radiographs: A Systematic Review and Multilevel Meta-Analysis.

Artificial Intelligence (AI) is a dynamic area of computer science that is constantly expanding its practical benefits in various fields. The aim of this study was to analyze AI-guided radiological assessment of femoral neck fractures by performing a systematic review and multilevel meta-analysis of primary studies. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) on May 21, 2024 [CRD42024541055]. The updated Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were strictly followed. A systematic literature search of PubMed, Web of Science, Ovid (Med), and Epistemonikos databases was conducted until May 31, 2024. Critical appraisal using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool showed that the overall quality of the included studies was moderate. In addition, publication bias was presented in funnel plots. A frequentist multilevel meta-analysis was performed using a random effects model with inverse variance and restricted maximum likelihood heterogeneity estimator with Hartung-Knapp adjustment. The accuracy between AI-based and human assessment of femoral neck fractures, sensitivity and specificity with 95% confidence intervals (CIs) were calculated. Study heterogeneity was assessed using the Higgins test I2 (low heterogeneity <25%, moderate heterogeneity: 25%-75%, and high heterogeneity >75%). Finally, 11 studies with a total of 21,163 radiographs were included for meta-analysis. The results of the study quality assessment using the QUADAS-2 tool are presented in Table 2. The funnel plots indicated a moderate publication bias. The AI showed excellent accuracy in assessment of femoral neck fractures (Accuracy = 0.91, 95% CI 0.83 to 0.96; I2 = 99%; p < 0.01). The AI showed good sensitivity in assessment of femoral neck fractures (Sensitivity = 0.87, 95% CI 0.77 to 0.93; I2 = 98%; p < 0.01). The AI showed excellent specificity in assessment of femoral neck fractures (Specificity = 0.91, 95% CI 0.77 to 0.97; I2 = 97%; p < 0.01). AI-guided radiological assessment of femoral neck fractures showed excellent accuracy and specificity as well as good sensitivity. The use of AI as a faster and more reliable assessment tool and as an aid in radiological routine seems justified.

Artificial intelligence-based assessment of leg axis parameters shows excellent agreement with human raters: A systematic review and meta-analysis.

PURPOSE: The aim of this study was to conduct a systematic review and meta-analysis on the reliability and applicability of artificial intelligence (AI)-based analysis of leg axis parameters. We hypothesized that AI-based leg axis measurements would be less time-consuming and as accurate as those performed by human raters. METHODS: The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO). PubMed, Epistemonikos, and Web of Science were searched up to 24 February 2024, using a BOOLEAN search strategy. Titles and abstracts of identified records were screened through a stepwise process. Data extraction and quality assessment of the included papers were followed by a frequentist meta-analysis employing a common effect/random effects model with inverse variance and the Sidik-Jonkman heterogeneity estimator. RESULTS: A total of 13 studies encompassing 3192 patients were included in this meta-analysis. All studies compared AI-based leg axis measurements on long-leg radiographs (LLR) with those performed by human raters. The parameters hip knee ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and joint-line convergence angle (JLCA) showed excellent agreement between AI and human raters. The AI system was approximately 3 min faster in reading standing long-leg anteroposterior radiographs (LLRs) compared with human raters. CONCLUSION: AI-based assessment of leg axis parameters is an efficient, accurate, and time-saving procedure. The quality of AI-based assessment of the investigated parameters does not appear to be affected by the presence of implants or pathological conditions. LEVEL OF EVIDENCE: Level I.

Indirect comparisons of traction table versus standard table in total hip arthroplasty through direct anterior approach: a systematic review and frequentist network meta-analysis.

BACKGROUND: It remains unclear whether the use of an orthopaedic traction table (TT) in direct anterior approach (DAA) total hip arthroplasty (THA) results in better outcomes. The aim of this systematic review and network meta-analysis was to compare the THA outcomes through DAA on a standard operating table and the THA outcomes through DAA on a TT. METHODS: PubMed, Epistemonikos, and Google Scholar were searched for relevant randomized controlled trials (RCTs) up to 01 January 2024. An indirect comparison in network meta-analysis was performed to assess treatment effects between DAA on a TT and DAA on a standard table, using fixed-effects and random-effects models estimated with frequentist approach and consistency assumption. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were estimated for continuous variables and odds ratios (ORs) with 95% CIs were estimated for binary variables. RESULTS: The systematic review of the literature identified 43 RCTs with a total of 2,258 patients. DAA with TT had a 102.3 mL higher intraoperative blood loss and a 0.6 mmol/L lower Hb 3 days postoperatively compared with DAA without TT (SMD = 102.33, 95% CI 47.62 to 157.04; SMD = - 0.60, 95% CI - 1.19 to - 0.00). DAA with TT had a 0.15 lower periprosthetic fracture OR compared with DAA without TT (OR 0.15, 95% CI 0.03 to 0.86). There were no further significant differences in surgical, radiological, functional outcomes and in complication rates. CONCLUSION: Based on our findings and taking into account the limitations, we recommend that particular attention be paid to the risk of periprosthetic fracture in DAA on a standard operating table and blood loss in DAA with TT. Since numerous other surgical, radiological, functional outcome parameters and other complication rates studied showed no significant difference between DAA on a standard operating table and DAA with TT, no recommendation for a change in surgical technique seems justified. LEVEL OF EVIDENCE: Level I evidence, because this is a systematic review and meta-analysis of randomized controlled trials.

Indirect comparison in network meta-analysis between SuperPATH, direct anterior and conventional approach hemiarthroplasty in patients with femoral neck fracture.

BACKGROUND: The aim of the study was to compare the short-term outcome of SuperPATH, direct anterior (DAA) and conventional approach (CA) hemiarthroplasty (HA) in patients with femoral neck fractures using a network meta-analysis. METHODS: PubMed, China National Knowledge Infrastructure, Epistemonikos, and Embase were searched until May 31, 2024. In a network meta-analysis, mean differences with 95% confidence intervals were calculated using the Hartung-Knapp-Sidik-Jonkman method and a fixed/random effects model for continuous outcomes, and odds ratios with 95% confidence intervals were calculated using the Mantel-Haenszel method and a fixed/random effects model for dichotomous outcomes. RESULTS: The literature search identified a total of 9 randomized controlled trials on SuperPATH with 762 patients and 8 randomized controlled trials on DAA with 641 patients. In the overall ranking, SuperPATH was placed first, DAA second and CA third. SuperPATH HA was best in 7, second best in 2 and third best in 1 of the 10 outcome parameters. DAA HA was best in 2 and second best in 8 of the 10 outcome parameters. CA HA was best in 1 and third best in 9 of the 10 outcome parameters. In the indirect comparison between SuperPATH HA and DAA HA, SuperPATH HA had a 1.36 point lower visual analog scale at 2 to 7 days postoperatively and a 0.17 lower overall complication rate compared to DAA. CONCLUSION: For the treatment of patients with femoral neck fractures, SuperPATH HA ranked first, DAA HA ranked second and CA HA ranked third. Based on the results, we recommend that trauma surgeons increase their use of minimally invasive hip HA techniques. It should be noted that SuperPATH HA had a significantly lower overall complication rate compared to DAA HA when the minimally invasive technique was chosen.

The influence of operation time for hip hemiarthroplasty on complication rates and mortality in patients with femoral neck fracture: a retrospective data analysis.

BACKGROUND: The aim of the present study was to investigate the influence of various factors, in particular operation time, on mortality and complication rates in patients with femoral neck fractures who have undergone hip hemiarthroplasty (HHA) and to determine a cut-off value above which mortality and complication rates increase significantly. METHODS: Cases of patients with femoral neck fracture treated with HHA between 1 January 2017 and 31 December 2023 were screened for eligibility. Multiple logistic regressions were calculated to determine which factors (patient age, experience of surgeon, patient sex, ASA score, time to surgery, operation time) influenced the incidence of complications and mortality. The exact cut-off value for complications and mortality was determined using the Youden index of the ROC curve (sensitivity vs. specificity) of logistic regression. RESULTS: A total of 552 patients were considered eligible for this study. During the 90-day follow-up period after HHA, 50 deaths and 34 complications were recorded, giving a mortality rate of 9.1%, and a complication rate of 6.2%. Of the 34 complications recorded, 32.3% were infections, 14.7% dislocations, 20.7% trochanteric avulsions, 11.8% periprosthetic fractures, 11.8% nerve injuries, and 8.8% deep vein thrombosis. The odds ratio (OR) of a patient experiencing a complication is 2.2% higher for every minute increase in operation time (Exponential Beta - 1 = 0.022; p = 0.0363). The OR of a patient dying is 8.8% higher for each year increase in age (Exponential Beta - 1 = 0.088; p = 0.0007). When surgery was performed by a certified orthopaedic surgeon the mortality rate lowered by 61.5% in comparison to the surgery performed by a trainee (1 - Exponential Beta = 0.594; p = 0.0120). Male patients have a 168.7% higher OR for mortality than female patients (Exponential Beta - 1 = 1.687; p = 0.0017). Patients with an operation time of ≥ 86 min. have a 111.8% higher OR for mortality than patients with an operation time of < 86 min. (Exponential Beta - 1 = 1.118). CONCLUSION: This retrospective data analysis found that the risk of a patient experiencing a complication was 2.2% higher for every minute increase in operation time. Patients with an operation time above the cut-off of 86 min had a 111.8% higher risk of mortality than those with an operation time below the cut-off. Other influencing factors that operators should be aware of include patient age, male sex, and operator experience.

Inferior patellar mobility before and after knee arthroplasty: A comparison with healthy knees.

PURPOSE: The aim of this study was to evaluate patellar mobility in patients before and after knee arthroplasty (KA) and compare it with that of healthy subjects. It was hypothesised that patellar mobility is diminished in patients with osteoarthritis (OA) and remains unchanged after KA. METHODS: A total of 101 patients (59 females and 42 males) with a mean age of 70.9 ± 9.9 years underwent KA and were compared with 25 healthy individuals (seven females and 18 males) with a mean age of 32.3 ± 9.3 years. Mediolateral patellar displacement was measured by applying a force of 10 N, and the medial and lateral patellar shifts were recorded separately using a validated novel patellostabilometer. Patients were examined preoperatively and at 3 months postoperatively, assessing the range of knee motion and the clinical and functional status based on the Oxford Knee Score (OKS), Kujala Score, subjective Knee Society Score (sKSS), Forgotten Joint Score (FJS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC). RESULTS: Total patellar displacement was 42.1 ± 6 mm for healthy subjects, 31 ± 6 mm before surgery and 32.8 ± 7.8 mm after surgery in osteoarthritic patients (p < 0.01). The mean lateral patellar shift differed significantly between healthy individuals (17.9 ± 4 mm) and osteoarthritic patients (15.1 ± 6 mm) (p < 0.01). The mean medial patellar mobility of healthy individuals (24.2 ± 7 mm) was significantly greater than that of osteoarthritic patients (15.8 ± 4.8 mm) (p < 0.01). All scores improved significantly postoperatively. No correlation was found between patellar mobility and OKS, Kujala Score, sKSS, FJS and WOMAC (r = -0.11). Improvement in patellar mobility also showed no correlation with clinical outcomes according to OKS, Kujala Score, sKSS, FJS and WOMAC (r = 0.08). CONCLUSION: This study has demonstrated reduced patellar mobility in patients with OA. While patellar mobility significantly improved after KA, it may not hold clinical significance (p = 0.04). No impact on clinical outcome can be expected when the presurgical patella mobility is preserved in KA. LEVEL OF EVIDENCE: Level IV.

Patient-related Predictors for the Functional Outcome of SuperPATH Hemiarthroplasty versus Conventional Approach Hemiarthroplasty: A Systematic Review and Meta-regression Analysis of Randomized Controlled Trials.

Specialist literature lacks evidence that explores associations between patient characteristics and the beneficial treatment effect of SuperPATH hemiarthroplasty (HA) compared with conventional approach (CA) HA. To investigate and identify patient-related predictors of the effect size of the short-term functional outcome of SuperPATH HA and CA HA by performing a systematic review and meta-regression analysis of randomized controlled trials (RCTs). A systematic search of literature was performed in PubMed, CNKI, CENTRAL of The Cochrane Library, Clinical trials, and Google Scholar until August 25, 2023. For the continuous outcome parameter Harris hip score (HHS) ≤1 week and 3 months postoperatively, mean differences (MDs) with 95% confidence intervals (CIs) were calculated. A meta-regression analysis was based on random-effects meta-analysis using the Hartung-Knapp-Sidik-Jonkman method for continuous covariates. A total of five RCTs with 404 patients were found. The following predictors of HHS ≤1 week postoperatively were identified: patient age (predictor estimate = 1.29; p < 0.01), patient age groups (predictor estimate = 14.07; p < 0.01), time to mobilization (predictor estimate = 5.51; p < 0.01). The following predictors of HHS 3 months postoperatively were identified: incision length (predictor estimate = -2.12; p < 0.01); intraoperative blood loss (predictor estimate = 0.02; p < 0.01). Patient age, time to mobilization, incision length, and intraoperative blood loss were identified as predictors of the effect size of early postoperative functional outcome as measured by HHS. Elderly patients, particularly those over 70 years of age, appear to benefit from SuperPATH HA. Based on these findings, and taking into account our limitations, we recommend that the use of minimally invasive SuperPATH HA in elderly patients should be more widely considered and not limited to elective THA patients.

High three-dimensional accuracy of component placement and lower limb alignment using a robotic arm-assisted system and gap-balancing instrument in total knee arthroplasty.

PURPOSE: It was hypothesized that robotic arm-assisted total knee arthroplasty (RA-TKA) using additionally a gap-balancing instrumentation will show high accuracy in executing the planning in femoral and tibial component placement throughout the range of knee motion (ROM) during TKA surgery. METHODS: Prospectively collected data were analysed for patients undergoing RA-TKA. A cruciate retaining cemented design was implanted using the MAKO® robotic system. Lower limb alignment at 0°, 30°, 45°, 60° and 90° of flexion was recorded at the beginning of surgery and finally after implantation of the components. A ligament tensioner was inserted after tibial precut to measure the extension and flexion gap, and final component placement was planned based on 3D CT images. Femoral and tibial component placement was measured in all three planes. RESULTS: A total of 104 patients were included (mean age 69.4 ± 9 years; 44 male, 60 female). The difference in component placement after planning and final implantation showed less valgus of 0.7° ± 1.4° (p < 0.001), less external rotation of 0.6° ± 1.9° (p = 0.001) and less flexion of 0.9° ± 1.8° (p < 0.001) for the femoral component. The tibial component was placed in more varus of 0.2° ± 0.9° (p = 0.056) and more posterior slope of 0.5° ± 0.9° (p < 0.001). The lower limb alignment in extension was 4.4° ± 5.2° of varus of the native knee and changed to 1.2° ± 1.9° of varus after TKA (p < 0.01). CONCLUSION: Robotic-assisted TKA helps to achieve the target of alignment and component placement very close to the planning. It allows optimal component placement of off-the-shelf implants respecting patient's specific anatomy. LEVEL OF EVIDENCE: Level II.

Development of the INpaTiEnt Rehabilitation App Compliance QuesTionnaire [INTERACT].

BACKGROUND: The elements of previously designed questionnaires do not take into consideration the burdens encountered in an inpatient hospital setting. The purpose of this study is to validate elements of a non-compliance survey in an in-hospital setting and discuss aspects of compliance with telerehabilitative physiotherapy in the early postoperative period. METHODS: A literature search was conducted to identify elements that prevent patients from performing their prescribed physical therapy exercises. These items were then evaluated by the expert review technique as described by Ikart. Afterwards, the synthesized survey was handed out to patients for the assessment of the quality of its items. RESULTS: The results of the expert review technique identified some conceptual and grammatical problems. This led to the adjustment of some of the elements. The quality of the resulting questionnaire was deemed to be good, as patients were able to fully understand the concepts and answer accordingly. A statistical analysis was conducted to evaluate the responses. CONCLUSIONS: The items of this second questionnaire have proven to be reliable to assess the compliance of patients in an in-hospital setting. These items will be added to the cross-culturally adapted items of a previous questionnaire.

Does Postoperative Mechanical Axis Alignment Have an Effect on Clinical Outcome of Primary Total Knee Arthroplasty? A Retrospective Cohort Study.

BACKGROUND: There is an ongoing debate whether patients with constitutional varus should be restored to neutral mechanical alignment following total knee arthroplasty (TKA). OBJECTIVE: The aim of this retrospective cohort study is to determine whether mild unintentional postoperative varus alignment (3°-6°) influences TKA outcome in patients with and without preoperative varus alignment due to medial osteoarthritis of the knee. METHODS: We analyzed 172 consecutive TKA cases between April 2011 and May 2014. Patients were divided into four groups based on their preoperative and postoperative hip-knee-ankle angles (HKA): preoperative varus ≤ 3° with postoperative varus position ≤ 3° (Group 1, n = 47); preoperative varus >3° with postoperative varus ≤ 3° (Group 2, n = 104); preoperative varus ≤ 3° with postoperative varus malalignment > 3° (Group 3, n = 3); and preoperative varus > 3° with postoperative varus malalignment > 3° (Group 4, n = 18). Patients were followed up until 2 years postoperatively. RESULTS: Knee Society Score and Western Ontario and McMaster University Osteoarthritis Index scores for all study groups increased following TKA, with no postoperative differences at any time point. Group 4 performed significantly better on the Forgotten Joint Score than Group 2 (p = 0.019). Group 4 performed significantly better on the High Flexion Knee Score than Group 2 (p = 0.004) and Group 1 (p = 0.019). All other between-group differences were not statistically significant. CONCLUSION: Residual postoperative varus alignment of the lower limb does not appear to adversely affect clinical outcome following TKA for varus-type osteoarthritis.

Expression of the voltage- and Ca2+-dependent BK potassium channel subunits BKß1 and BKß4 in rodent astrocytes.

Large-conductance Ca(2+) -activated (BK) potassium channels are centrally involved in neurovascular coupling, immunity, and neural transmission. The ability to be synergistically activated by membrane depolarization, different ligands and intracellular Ca(2+) links intracellular signaling and membrane excitability. The diverse physiological functions of BK channels crucially depend on regulatory ß subunits. Although first studies characterized the neuronal distribution of BKß subunits in the rodent brain, it is largely unknown which ß subunit proteins are expressed in astrocytes and thus mediate these regulatory effects. We therefore analyzed the expression of BKß subunits in rat and mouse brain and glial cell cultures. A monospecific polyclonal antibody against the BKß4 channel subunit was raised, affinity-purified and extensively characterized. BKß4 and to a lesser degree BKß1 transcripts and protein were detected in several astrocytic populations and cultured cells. Particularly strong BKß4 immunostaining was detected in astrocytic progenitors derived from the subventricular zone. The overlapping expression of BKα and BKß4 in astrocytes implies a functional relationship and suggests that BKß4 is an important accessory ß subunit for astrocytic BK channels. In addition, BKß4 might exert effects independent of the α subunit as functional heterologous co-expression of Nav1.6 and BKß4 resulted in reduced Nav1.6 sodium currents. Thus, BKß4 expression in astrocytes likely participates in regulating astrocytic voltage gradients and maintaining K(+) homeostasis, hence enabling astrocytes to fulfill their complex regulatory influence on proper brain function.

BKbeta1 subunits contribute to BK channel diversity in rat hypothalamic neurons.

Large conductance Ca(2+)-activated BK channels are important regulators of action potential duration and firing frequency in many neurons. As the pore-forming subunits of BK channels are encoded by a single gene, channel diversity is mainly generated by alternative splicing and interaction with auxiliary beta-subunits (BKbeta1-4). In hypothalamic neurons several BK channel subtypes have been described electrophysiologically; however, the distribution of BKbeta subunits is unknown so far. Therefore, an antibody against the large extracellular loop of the BKbeta1 subunit was raised, freed from cross-reactivity against BKbeta2-4 and affinity-purified. The resulting polyclonal monospecific BKbeta1 antibody was characterized by Western blot analysis, ELISA techniques and immunocytochemical staining of BKbeta1-4-transfected CHO and COS-1 cells. Regional and cellular distribution in the rat hypothalamus was analysed by immunocytochemistry and in situ hybridization experiments. Immunocytochemical staining of rat hypothalamic neurons indicates strong BKbeta1 expression in the supraoptic nucleus and the magno- and parvocellular parts of the paraventricular nucleus. Lower expression was found in periventricular nucleus, the arcuate nucleus and in the median eminence. Immunostaining was predominantly localized to somata. In addition, pericytes and ependymal epithelial cells showed BKbeta1 labelling. In all cases immunocytochemical results were supported by in situ hybridization.