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.

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.

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.

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.