Hoof care providers are pivotal for implementing biomechanical optimizations of the musculoskeletal system in the horse. Regular visits allow for the collection of longitudinal, quantitative information (\"normal ranges\"). Changes in movement symmetry, e.g., after shoeing, are indicative of alterations in weight-bearing and push-off force production. Ten Warmblood show jumping horses (7-13 years; 7 geldings, 3 mares) underwent forelimb re-shoeing with rolled rocker shoes, one limb at a time (\"limb-by-limb\"). Movement symmetry was measured with inertial sensors attached to the head, withers, and pelvis during straight-line trot and lunging. Normalized differences pre/post re-shoeing were compared to published test-retest repeatability values. Mixed-model analysis with random factors horse and limb within horse and fixed factors surface and exercise direction evaluated movement symmetry changes (p < 0.05, Bonferroni correction). Withers movement indicated increased forelimb push-off with the re-shod limb on the inside of the circle and reduced weight-bearing with the re-shod limb and the ipsilateral hind limb on hard ground compared to soft ground. Movement symmetry measurements indicate that a rolled rocker shoe allows for increased push-off on soft ground in trot in a circle. Similar studies should study different types of shoes for improved practically relevant knowledge about shoeing mechanics, working towards evidence-based preventative shoeing.

BACKGROUND: This study aimed to investigate ankle syndesmosis in healthy subjects under non-weight bearing (NWB) and weight bearing (WB) conditions using two US methods.
METHODS: The anterior tibiofibular clear space (ATFCS) was measured in healthy subjects in NWB and WB conditions using two US procedures. Method 1 measured 10 mm above the ankle joint and Method 2 measured 30° from the line of 10 mm above the ankle joint.
RESULTS: A total of 60 ankles from 30 subjects (male/female, 15/15) were included. There was a significant difference in the ATFCS between the two US methods (p < 0.001), and Method 2 was better at detecting the change in diastasis from NWB to WB conditions. The ATFCS was significantly greater on WB than on NWB, irrespective of the US method.
CONCLUSIONS: Method 2 was better at detecting diastasis of the syndesmosis from NWB to WB conditions. The influence of WB needs to be considered when evaluating syndesmosis using US.
METHODS: Cross-sectional cohort study; Level of evidence, Ⅳ.

Background: Femoral neck fractures are among the most common types of fractures and particularly affect elderly patients. Two of the most common treatment strategies are total hip arthroplasty (THA) and bipolar hemiarthroplasty (BA). However, the role of the different treatment strategies in the postoperative weight-bearing ability in the early postoperative phase is still not entirely clear. Methods: Patients who underwent either THA or BA were consecutively included in our prospective cohort study. Gait analysis was performed during the early postoperative period. The gait analysis consisted of a walking distance of 40 m coupled with the turning movement in between. During the gait analysis, the duration of the measurement, the maximum peak force and the average peak force were recorded. Results: A total of 39 patients were included, 25 of whom underwent BA and 14 of whom underwent THA. The maximum peak force during the gait analysis was, on average, 80.6% ± 19.5 of the body weight in the BA group and 78.9% ± 21.6 in the THA group. The additionally determined average peak force during the entire gait analysis was 66.8% ± 15.8 of the body weight in the BA group and 60.5% ± 15.6 in the THA group. Conclusions: Patients with femoral neck fractures undergoing THA and BA can achieve sufficient weight bearing on the operated leg in the early postoperative period. In our study, BA did not allow for a significantly higher average and maximum loading capacity compared with THA.

A hip joint fracture includes a break in the thigh (femur) or coxa bone near the pelvis. During fracture healing, stability and weight bearing by the affected limb are key indicators to measure patients\' improvement. Conventionally, the rehabilitation effectiveness is monitored through clinical examinations, patients\' feedback, and few studies also reported instrumented gait evaluations. A gap remains there to numerically quantify the recovery in patients\' stability and weight bearing in response to rehabilitation therapies. This study introduces Nyquist and Bode (N&B) methods to analyse the instrumented gait signals further and evaluate gait stability in hip fracture patients during weight loading and unloading transitions. The centre of pressure (CoP) data was recorded using force plates for conditions: coxa hip fracture (HC), femur hip fracture (HF), and normal hip joint (NH). The time rate of CoP signals illustrated two major impulses during the loading and unloading phases which were modelled in time and frequency domains. The frequency models were further analysed by applying N&B methods and stability margins were computed for both impaired and healthy conditions. Results illustrated a significant decrease (Kruskal-Wallis\'s test, p < 0.001) in the intralimb walking stability of both fracture conditions. Further, Spearman\'s correlation between CoP velocities of fractured and intact limbs illustrated significant interlimb dependencies to maintain walking stability (p < 0.001) during weight loading and unloading transitions. Overall, the HF impairment illustrated the least intralimb walking stability and relatively greater interlimb dependencies. Clinically, these methods and findings are important to measure the recovery in patients undergoing rehabilitation after a hip joint or other lower limb impairments.

Background Intertrochanteric fractures, which occur in the hip of older individuals due to the weak and brittle structure of the bone caused by osteoporosis, make up over 50% of all hip fractures. There are several treatment options available for these fractures. The major objective of this study was to carry out a comparative analysis to evaluate the efficacy of dynamic hip screws (DHS) and proximal femoral nails (PFN) in treating intertrochanteric fractures. Methodology Two hundred instances of intertrochanteric hip fractures were surgically treated between July 2022 and January 2024 at a tertiary care facility. The evaluation of fractures was conducted in two groups, namely, group 1, which consisted of 140 patients, each having a fracture in one hip, treated using the DHS method. Group 2 consisted of 60 patients, each having a fracture in one hip, treated using the PFN technique. The evaluation of functional results was performed with the Harris hip score. Results In the investigation within these groups, group 1 produced excellent outcomes in 53 patients, which accounts for 37.86% of the total. In group 2, the expected results were achieved in 34 patients (56.67%). Achieved outcomes were favorable in 75 (53.57%) individuals in group 1 and 21 (35%) in group 2. Out of the individuals in group 1, eight (5.71%) saw benefits, whereas four (1.6%) did not gain significantly. In group 2, five (8.33%) individuals benefitted. None of the patients in group 2 had unfavorable outcomes. Conclusion While both PFN and DHS provide comparable outcomes in stable bone, PFN demonstrated superior results in cases of unstable bone. The use of PFN results in reduced surgical duration and a smaller surgical opening. Additionally, PFN exhibited superior specificity compared to DHS, especially in cases with stable intertrochanteric bone.

BACKGROUND: Demographics of patients who sustain geriatric distal femoral fractures (DFF) match those of patients with neck-of-femur fractures but have limited evidence with which to support post-operative weightbearing protocols.
OBJECTIVE: This systematic review sought to identify any difference in outcomes for elderly patients with DFF who were allowed early versus delayed weightbearing postoperatively.
METHODS: DATA SOURCES: PubMed, Medline, Embase and The Cochrane Library, reference lists of retrieved articles.
METHODS: English language papers published between January 2010 and February 2023 with AO-OTA type 33A, B and C femoral fractures as well as Lewis and Rorabeck Type I and II periprosthetic DFF surgically treated with either a lateral locking plate or retrograde intramedullary nail and an average patient age of ≥ 60 years.
METHODS: Studies were assessed for inclusion by two authors and quality was assessed using the MINORS tool.
RESULTS: Sixteen studies were included, Meta-analysis of non-union, malunion, infection, delayed union and implant complications was performed using Microsoft Excel and the MetaXL extension. The data on return to mobility were presented in narrative form. The analyses demonstrated no difference between the early and delayed weightbearing groups.
CONCLUSIONS: There are no significant differences in complication rates between early versus delayed weightbearing after surgery for DFF in an elderly population. The study results are limited by high heterogeneity and low-quality studies. High quality, prospective studies are needed to determine the ideal postoperative weightbearing protocol.
METHODS: Level III, Systematic Review and Meta-analysis of Level III studies. International Prospective Register of Systematic Reviews registration-Prospero CRD42022371460.

Introduction The goal of total knee arthroplasty is to replace diseased cartilage and bone with an artificial implant to improve the patient\'s quality of life. The knee has historically been reconstructed to the patient\'s mechanical axis (MA). However, kinematically aligned techniques have been increasingly used. Kinematic alignment requires less soft-tissue resection and aligns the knee with what is anatomically natural to the patient, while there is concern that kinematically aligned knees will lead to earlier failure due to potential unequal weight distribution on the implant. The purpose of this study is to compare the parallelism from the floor of the joint-line cuts using kinematic and mechanical alignment and understand if the MA is a proper estimation of the tibial-ankle axis (TA). Methods A retrospective study was conducted by recruiting all high tibial osteotomy and distal femoral osteotomy recipients operated on by two surgeons in two MedStar Health hospitals from 01/2013 to 07/2020 with full-length films in preparation for restorative procedures. Baseline osteoarthritis was graded using the Kellgren-Lawrence classification system with all patients presenting as Grade 0. The TA and the joint-line orientations of the MA and kinematic axis (KA) were measured on 66 legs. The average distance from parallelism to the ground was compared between the MA and the KA and between the MA and the TA using a paired t-test. Results KA joint-line orientation (1.705° deviation) was more parallel to the floor in the bipedal stance phase than the MA (2.316° deviation, p=0.0156). The MA (2.316° deviation) was not a proper estimation of the TA (4.278° deviation, p=0.0001). Conclusion By utilizing the KA technique, the restoration of the natural joint line, as well as a joint that is more parallel to the floor in the stance phase compared to the MA, is achieved. The parallelism to the ground of the KA during the bipedal stance phase suggests an even load distribution across the knee. In addition, due to its similarity to the KA and anatomical significance in weight-bearing distribution, further investigation into the hip-to-calcaneal axis as an approximation of the joint line is warranted.

The effects of mechanical unloading after anterior cruciate ligament (ACL) reconstruction on bone and marrow adipose tissue (MAT) are unclear. We investigated weight bearing effects on bone and MAT after ACL reconstruction. Rats underwent unilateral knee ACL transection and reconstruction, followed by hindlimb unloading (non-weight bearing), no intervention (low-weight bearing, the hindlimb standing time ratio (STR; operated/contralateral) during treadmill locomotion ranging from 0.55 to 0.91), or sustained morphine administration (moderate-weight bearing, STR ranging from 0.80 to 0.95). Untreated rats were used as controls. At 7 or 14 days after surgery, changes in trabecular bone and MAT in the proximal tibial were assessed histologically. Histological assessments at 7 or 14 days after surgery showed that ACL reconstruction without post-operative intervention did not significantly change trabecular bone and MAT areas. Hindlimb unloading after ACL reconstruction induced MAT accumulation with adipocyte hyperplasia and hypertrophy within 14 days, but did not significantly affect trabecular bone area. Increased weight bearing through morphine administration did not affect trabecular bone and MAT parameters. Our results suggest that early weight bearing after ACL reconstruction is important in reducing MAT accumulation, and that reduction in weight bearing alone is not sufficient to induce bone loss early after ACL reconstruction.

The cholinergic system has been found to make an anti-inflammatory effect through the cholinergic anti-inflammatory pathway (CAIP), which suppresses the production of pro-inflammatory cytokines by secreting acetylcholine, a major neurotransmitter. However, no studies have been conducted on the effects of CAIP on joint pain and inflammation. In this study, we investigated the effects of muscarinic acetylcholine receptors (mAChRs) in knee arthritis. To examine pain behavioral changes, atropine (or saline for sham control) was pretreated in the joint cavity of rats at 1 % carrageenan + 5, 10, and 30 μL and the dynamic weight-bearing evaluation was performed. Synovial membranes were collected and cyclooxygenase-2 (COX-2) and interleukin-1β (IL-1β) were measured using a western blot. Hematoxylin and eosin staining was performed. Compared to that of the sham group, the weight-bearing of the affected knee joint significantly increased in the 1 % carrageenan + 10 μL atropine group (p < 0.05). However, no significant changes were observed in the 1 % carrageenan + 5 and 30 μL atropine groups. COX-2 and IL-1β and the number of inflammatory cells in synovial membrane significantly increased with 1 % carrageenan + 10 μL of atropine (p < 0.05). These results suggest that cholinergic system is involved in knee joint pain and inflammation and that mAChRs are potential therapeutic targets for knee joint arthritis.

Female athletes subjected to various types of impact loading, especially over a long period of time, may experience changes in their pelvic orientation, which may affect their sport performance and increase the likelihood of injury. The aim of the present study was to determine whether female athletes involved in high-impact loading sports (HILS), odd-impact loading sports (OILS), and repetitive non-impact loading sports (NILS) demonstrate changes in pelvis orientation compared to non-athletes (NATH). Pelvic orientation was determined using Euler/Cardan angles, calculated from the coordinates of the right, and left anterior superior iliac spines and pubic symphysis via a novel method. Two-way ANOVA tests showed significant differences between groups for pelvis position in the frontal plane (p < 0.05), with HILS and OILS demonstrating greater pelvic obliquity compared to NILS athletes and NATH. Significant main effects were also obtained for directions within the sagittal plane (p < 0.001). Significant within-group differences were observed in sagittal pelvic position among female athletes engaged in NILS (p < 0.01) and non-athletes (NATH) (p < 0.05), with a greater anterior pelvic tilt compared to posterior. Our findings suggest that pelvis orientation in female athletes across sports is influenced by sport-specific impact loads, potentially affecting performance and injury occurrence.