This research was supported by the National Institutes of Health (NIH) under grant numbers S10 RR026565, R21 AR063844, F32 AR067075, R01 R077636, R56 AR074416, R01 GM083925. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

The authors have no conflicts of interest.

Dual fluoroscopy is a powerful tool for the investigation of in vivo kinematics, especially for the hip, which is difficult to accurately measure using traditional optical motion capture. However, fluoroscopy equipment is specialized, wherein a unique system setup may be required when imaging other joints of the human body. For example, several modifications were made to the mounting of the image intensifiers, positioning of the system, and settings of the beam energy in the application of dual fluoroscopy to th...

The number of total hip arthroplasty (THA) procedures performed on adults aged 45-64 years suffering from hip osteoarthritis (OA) more than doubled between 2000 and 20101. Based on the increases in THA procedures from 2000 to 2014, a recent study predicted that the overall number of yearly procedures may triple over the next twenty years2. These large increases in THA procedures are alarming considering that current treatment costs exceed $18 billion annually in the United States alone3.
Developmental dysplasia of the hip (DDH) and femoroacetabular impingement syndrome (FAIS), which describe an under- or over-constrained hip, respectively, are believed to be the primary etiology of hip OA4. The high prevalence of these structural hip deformities in individuals undergoing THA was initially described more than three decades ago5. Still, the relationship between abnormal hip anatomy and osteoarthritis is not well understood. One challenge to improving the working understanding of the role of deformities in the development of hip OA is that abnormal hip morphology is very common amongst asymptomatic adults. Notably, studies have observed morphology associated with cam-type FAIS in approximately 35% of the general population6, 83% of senior athletes7, and more than 95% of collegiate male athletes8. In another study of female collegiate athletes, 60% of participants had radiographic evidence of cam FAIS, and 30% had evidence of DDH9.
Studies demonstrating a high prevalence of deformities amongst individuals without hip pain point to the possibility that morphology commonly associated with FAIS and DDH may be a natural variant that only becomes symptomatic under certain conditions. However, the interaction between hip anatomy and hip biomechanics is not well understood. Notably, there are known difficulties with measuring hip joint motion using traditional optical motion capture technology. First, the joint is relatively deep within the body, such that the location of the hip joint center is difficult to both identify and track dynamically using optical skin marker motion capture, with errors on the same order of magnitude as the radius of the femoral head10,11. Second, the hip joint is surrounded by large soft tissue bulk, including subcutaneous fat and muscle, that moves relative to the underlying bone, resulting in soft tissue artifact12,13,14. Finally, using optical tracking of skin markers, kinematics are evaluated relative to generalized anatomy and thus do not provide insight into how subtle morphological differences might affect the biomechanics of the joint.
To address the lack of accurate kinematics in combination with subject-specific bone morphology, both single and dual fluoroscopy systems have been developed for analyzing other natural joint systems15,16,17. However, this technology has only recently been applied to the native hip joint, likely due to the difficulty in acquiring high-quality images through the soft tissue surrounding the hip. The methodology to accurately measure in vivo hip joint motion and display this motion relative to subject-specific bone anatomy is described herein. The resulting arthrokinematics provide an unparalleled ability to investigate the subtle interplay between bone morphology and biomechanics.
Herein, the procedures for acquiring and processing dual fluoroscopy images of the hip during activities of daily living have been described. Owing to the desire to capture whole-body kinematics with optical marker tracking simultaneously with dual fluoroscopy images, the data collection protocol requires coordination between several sources of data. Calibration of the dual fluoroscopy system utilizes plexiglass structures implanted with metallic beads that can be directly identified and tracked as markers. In contrast, dynamic bone motion is tracked using markerless tracking, which utilizes only the CT-based radiographic density of the bones to define orientation. Dynamic motion is then tracked simultaneously using dual fluoroscopy and motion capture data that are spatially and temporally synced.
The systems are synced spatially during calibration through concurrent imaging of a cube with both reflective markers and implanted metal beads and the generation of a common coordinate system. The systems are synced temporally for each activity or capture through the use of a split electronic trigger, which sends a signal to end the recording of the dual fluoroscopy cameras and interrupts a constant 5 V input to the motion capture system. This coordinated protocol enables the quantification of the position of body segments that fall outside the combined field of view of the dual fluoroscopy system, expression of kinematic results relative to gait-normalized events, and characterization of the soft tissue deformation around the femur and pelvis.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Amira Software</td>
			<td>ThermoFisher Scientific</td>
			<td>Version 6.0</td>
			<td></td>
		</tr>
		<tr>
			<td>Calibration Cube</td>
			<td></td>
			<td>Custom</td>
			<td>36 steel beads (3 mm diameter, spacing 6.35 cm, uncertainty 0.0036 mm)</td>
		</tr>
		<tr>
			<td>Calibration Wand</td>
			<td>Vicon</td>
			<td>Active Wand</td>
			<td></td>
		</tr>
		<tr>
			<td>CT Scanner</td>
			<td>Siemens AG</td>
			<td colspan="2">SOMATOM Definition 128 CT</td>
		</tr>
		<tr>
			<td>Distortion Correction Grid</td>
			<td></td>
			<td>Custom</td>
			<td>Acrylic plate with a grid of steel beads spaced 10 mm and 31 beads across the diameter (2 mm diameter)</td>
		</tr>
		<tr>
			<td>Dynamic Calibration Plate</td>
			<td></td>
			<td>Custom</td>
			<td>Acrylic plate with 3 steel beads spaced 30 mm (2 mm diameter, uncertainty 0.0013 mm)</td>
		</tr>
		<tr>
			<td>Emitter (2)</td>
			<td>Varian Interay; remanufactured by Radiological Imaging Services</td>
			<td>Housing B-100/Tube A-142</td>
			<td></td>
		</tr>
		<tr>
			<td>Epinephrine</td>
			<td>Hospira</td>
			<td>Injection, USP 10 mg/mL</td>
			<td></td>
		</tr>
		<tr>
			<td>FEBioStudio Software</td>
			<td>FEBio.org</td>
			<td>Version 1.3</td>
			<td>Mesh processing and kinematic visualization</td>
		</tr>
		<tr>
			<td>Graphical Processing Unit</td>
			<td>Nvidia</td>
			<td>Tesla</td>
			<td></td>
		</tr>
		<tr>
			<td>Hare Traction Splint</td>
			<td>DynaMed</td>
			<td>Trac-III, Model No. 95201</td>
			<td></td>
		</tr>
		<tr>
			<td>High-speed Camera (2)</td>
			<td>Vision Research, Inc.</td>
			<td>Phantom Micro 3</td>
			<td></td>
		</tr>
		<tr>
			<td>Image Intensifier (2)</td>
			<td>Dunlee, Inc.; remanufactured by Radiological Imaging Services</td>
			<td>T12964P/S</td>
			<td></td>
		</tr>
		<tr>
			<td>Iohexol injection</td>
			<td>GE Healthcare</td>
			<td>Omnipaque 240 mgI/mL</td>
			<td>517.7 mg iohexol, 1.21 mg tromethamine, 0.1 mg edetate calcium disodium per mL</td>
		</tr>
		<tr>
			<td>ImageJ</td>
			<td>National Institutes of Health and Laboratory for Optical and Computational Instrumentation</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Lidocaine HCl</td>
			<td>Hospira</td>
			<td>Injection, USP 10 mg/mL</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser and Mirror Alignment System</td>
			<td></td>
			<td>Custom</td>
			<td>Three lasers adhered to acrylic plate that attaches to emitter, mirror attaches to face of image intensifier</td>
		</tr>
		<tr>
			<td>Markless Tracking Workbench</td>
			<td>Henry Ford Hospital, Custom Software</td>
			<td>Custom</td>
			<td></td>
		</tr>
		<tr>
			<td>MATLAB Software</td>
			<td>Mathworks, Inc.</td>
			<td>Version R2017b</td>
			<td></td>
		</tr>
		<tr>
			<td>Motion Capture Camera (10)</td>
			<td>Vicon</td>
			<td>Vantage</td>
			<td></td>
		</tr>
		<tr>
			<td>Nexus Software</td>
			<td>Vicon</td>
			<td>Version 2.8</td>
			<td>Motion capture</td>
		</tr>
		<tr>
			<td>Phantom Camera Control (PCC) Software</td>
			<td>Vision Research, Inc.</td>
			<td>Version 1.3</td>
			<td></td>
		</tr>
		<tr>
			<td>Pre-tape Spray Glue</td>
			<td>Mueller Sport Care</td>
			<td>Tuffner</td>
			<td></td>
		</tr>
		<tr>
			<td>Retroreflective Spherical Skin Markers</td>
			<td></td>
			<td></td>
			<td>14 mm</td>
		</tr>
		<tr>
			<td>Split Belt Fully Instrumented Treadmill</td>
			<td>Bertec Corporation</td>
			<td>Custom</td>
			<td></td>
		</tr>
		<tr>
			<td>Visual3D Software</td>
			<td>C-Motion Inc.</td>
			<td>Version 6.01</td>
			<td>Kinematic processing</td>
		</tr>
	</tbody>
</table>

in vivo quantification of hip arthrokinematics during dynamic weight-bearing activities using dual fluoroscopy

Several hip pathologies have been attributed to abnormal morphology with an underlying assumption of aberrant biomechanics. However, structure-function relationships at the joint level remain challenging to quantify due to difficulties in accurately measuring dynamic joint motion. The soft tissue artifact errors inherent in optical skin marker motion capture are exacerbated by the depth of the hip joint within the body and the large mass of soft tissue surrounding the joint. Thus, the complex relationship between bone shape and hip joint kinematics is more difficult to study accurately than in other joints. Herein, a protocol incorporating computed tomography (CT) arthrography, three-dimensional (3D) reconstruction of volumetric images, dual fluoroscopy, and optical motion capture to accurately measure the dynamic motion of the hip joint is presented. The technical and clinical studies that have applied dual fluoroscopy to study form-function relationships of the hip using this protocol are summarized, and the specific steps and future considerations for data acquisition, processing, and analysis are described.

Using dual fluoroscopy as a reference standard, the accuracy of skin-marker-based estimates of the hip joint center and the effect of soft-tissue artifact on kinematic and kinetic measurements were quantified22,23,24. The superior accuracy of dual fluoroscopy was then used to identify subtle differences in pelvic and hip joint kinematics between patients with FAIS and asymptomatic control participants25. ...

Watch this Scientific Journal Video about In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy at JoVE.com

In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Dual fluoroscopy accurately captures in vivo dynamic motion of human joints, which can be visualized relative to reconstructed anatomy (e.g., arthrokinematics). Herein, a detailed protocol to quantify hip arthrokinematics during weight-bearing activities of daily living is presented, including the integration of dual fluoroscopy with traditional skin marker motion capture.

In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Several hip pathologies have been attributed to abnormal morphology with an underlying assumption of aberrant biomechanics. However, structure-function ...

in-vivo-quantification-hip-arthrokinematics-during-dynamic-weight

Research

Education

JoVE Core

JoVE Journal

Anatomy and Physiology

Medicine

Unit 1

The Appendicular Skeleton

SCIENTISTS IN ACTION

2.9K Views.  University of Utah. Dual fluoroscopy accurately captures in vivo dynamic motion of human joints, which can be visualized relative to reconstructed anatomy (e.g., arthrokinematics). Herein, a detailed protocol to quantify hip arthrokinematics during weight-bearing activities of daily living is presented, including the integration of dual fluoroscopy with traditional skin marker motion capture. 

Video: In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

In vivo Dual Substrate Bioluminescent Imaging

Our understanding of how and when breast cancer cells transit from established primary tumors to metastatic sites has increased at an exceptional rate since the advent of in vivo bioluminescent imaging technologies 1-3. Indeed, the ability to locate and quantify tumor growth longitudinally in a single cohort of animals to completion of the study as opposed to sacrificing individual groups of animals at specific assay times has revolutionized how researchers investigate breast cancer metastasis. Unfortunately, current methodologies preclude the real-time assessment of critical changes that transpire in cell signaling systems as breast cancer cells (i) evolve within primary tumors, (ii) disseminate throughout the body, and (iii) reinitiate proliferative programs at sites of a metastatic lesion. However, recent advancements in bioluminescent imaging now make it possible to simultaneously quantify specific spatiotemporal changes in gene expression as a function of tumor development and metastatic progression via the use of dual substrate luminescence reactions. To do so, researchers take advantage for two light-producing luciferase enzymes isolated from the firefly (Photinus pyralis) and sea pansy (Renilla reniformis), both of which react to mutually exclusive substrates that previously facilitated their wide-spread use in in vitro cell-based reporter gene assays 4. Here we demonstrate the in vivo utility of these two enzymes such that one luminescence reaction specifically marks the size and location of a developing tumor, while the second luminescent reaction serves as a means to visualize the activation status of specific signaling systems during distinct stages of tumor and metastasis development. Thus, the objectives of this study are two-fold. First, we will describe the steps necessary to construct dual bioluminescent reporter cell lines, as well as those needed to facilitate their use in visualizing the spatiotemporal regulation of gene expression during specific steps of the metastatic cascade. Using the 4T1 model of breast cancer metastasis, we show that the in vivo activity of a synthetic Smad Binding Element (SBE) promoter was decreased dramatically in pulmonary metastasis as compared to that measured in the primary tumor 4-6. Recently, breast cancer metastasis was shown to be regulated by changes within the primary tumor microenvironment and reactive stroma, including those occurring in fibroblasts and infiltrating immune cells 7-9. Thus, our second objective will be to demonstrate the utility of dual bioluminescent techniques in monitoring the growth and localization of two unique cell populations harbored within a single animal during breast cancer growth and metastasis.

In vivo Dual Substrate Bioluminescent Imaging

Herein we describe the methods to construct, visualize, and quantify the bioluminescent reactions of both firefly and renilla luciferase enzymes expressed in metastatic breast cancer cells during their growth and metastasis in vivo.

Our understanding of how and when breast cancer cells transit from established primary tumors to metastatic sites has increased at an exceptional rate ...

Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that the application of this non-fluoroscopic catheter visualization system (NFCV) reduces fluoroscopy time and dose by 90-95% in a variety of electrophysiology (EP) procedures. This can be of relevance not only to the patients, but also to the nurses and physicians working in the EP lab. Furthermore, in a subset of indications such as supraventricular tachycardias, NFCV enables a fully non-fluoroscopic procedure and allows the lab staff to work without wearing lead aprons. With this protocol, we demonstrate that even complex procedures such as ablations of atrial fibrillation, that are typically associated with fluoroscopy times of &#62;30 min in conventional settings, can safely be performed with a reduction of &#62;90% in fluoroscopy exposure by the additional use of NFCV.

Radiation exposure is an underestimated risk in complex ablation procedures. Here, we describe a protocol to significantly decrease fluoroscopy time and dosage for both the patient and the lab staff by using a novel non-fluoroscopic catheter visualization system.

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that ...

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic patient tumors in different assays1. Human tumor xenografts represent the gold standard with respect to tumor biology, drug discovery, and metastasis research 2-4. Tumor xenografts can be derived from different types of material like tumor cell lines, tumor tissue from primary patient tumors4 or serially transplanted tumors. When propagated in vivo, xenografted tissue is infiltrated and vascularized by cells of mouse origin. Multiple factors such as the tumor entity, the origin of xenografted material, growth rate and region of transplantation influence the composition and the amount of mouse cells present in tumor xenografts. However, even when these factors are kept constant, the degree of mouse cell contamination is highly variable.
Contaminating mouse cells significantly impair downstream analyses of human tumor xenografts. As mouse fibroblasts show high plating efficacies and proliferation rates, they tend to overgrow cultures of human tumor cells, especially slowly proliferating subpopulations. Mouse cell derived DNA, mRNA, and protein components can bias downstream gene expression analysis, next-generation sequencing, as well as proteome analysis 5. To overcome these limitations, we have developed a fast and easy method to isolate untouched human tumor cells from xenografted tumor tissue. This procedure is based on the comprehensive depletion of cells of mouse origin by combining automated tissue dissociation with the benchtop tissue dissociator and magnetic cell sorting. Here, we demonstrate that human target cells can be can be obtained with purities higher than 96% within less than 20 min independent of the tumor type.

Human tumor xenografts are vascularized and infiltrated by cells of mouse origin during the growth phase in vivo. To circumvent the bias caused by these contaminating cells during downstream analysis, we developed a method allowing for comprehensive depletion of all mouse cells by magnetic cell sorting.

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic ...

Improved Registration of 3D CT Angiography with X-ray Fluoroscopy for Image Fusion During Transcatheter Aortic Valve Implantation

The fusion of 3D anatomical models derived from high-fidelity pre-interventional computed tomography angiography (CTA), and x-ray (XR) fluoroscopy to facilitate anatomical guidance is of huge interest for complex cardiac interventions like TAVI procedures with cerebral protection. Co-registration of CTA and XR has been introduced either based on additional intraoperative non-/contrast-enhanced cone-beam computed tomography (CBCT) or two separate aortograms. With the related increase of radiation exposure and/or contrast agent (CA) dose, a potential additional risk for the patient is introduced. Here, we propose a modified co-registration approach making use of arteriograms of the iliofemoral arteries, routinely performed during the femoral puncture and sheath introduction. On-the-fly refinement of the co-registration during the on-going procedure enables accurate co-registration without any additional angiograms, thus reducing CA, XR dose and procedure time, while simultaneously improving operator confidence and procedure safety.

The aim of this study was to improve the co-registration for image fusion (IF) of pre-interventional CT data with real-time x-ray (XR) fluoroscopy during transfemoral transcatheter aortic valve implantation (TAVI).

The fusion of 3D anatomical models derived from high-fidelity pre-interventional computed tomography angiography (CTA), and x-ray (XR) fluoroscopy to ...

Providing Visual Biofeedback Using Brightness Mode Ultrasound During a Golf Swing

Using ultrasound biofeedback in conjunction with verbal cueing can increase muscle thickness more than verbal cueing alone and may augment traditional rehabilitation techniques in an athletic, physically active population. Brightness mode (B-mode) ultrasound can be applied using frame-by-frame analysis synchronized with video to understand muscle thickness changes during these dynamic tasks. Visual biofeedback with ultrasound has been established in static positions for the muscles of the lateral abdominal wall. However, by securing the transducer to the abdomen using an elastic belt and foam block, biofeedback can be applied during more specific tasks prevalent in lifetime sports, such as golf. To analyze muscle activity during a golf swing, muscle thickness changes can be compared. The thickness must increase throughout the task, indicating that the muscle is more active. This methodology allows clinicians to immediately replay ultrasound videos for patients as a visual tool to instruct proper activity of the muscles of interest. For example, ultrasound can be used to target the external and internal obliques, which play an important role in swinging a golf club or any other rotational sport or activity. This methodology aims to increase oblique muscle thickness during the golf swing. Additionally, the timing of muscle contraction can be targeted by instructing the patient to contract the abdominal muscles at specific time points, such as the beginning of the downswing, with the goal of improving muscle firing patterns during tasks.

Brightness mode ultrasound can be used to provide visual biofeedback of the muscles of the lateral abdominal wall during a golf swing. Post-swing visual and verbal instruction can increase the muscle activation and timing of the external and internal obliques.

Using ultrasound biofeedback in conjunction with verbal cueing can increase muscle thickness more than verbal cueing alone and may augment traditional ...

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured between fascial borders at a given time point during an exercise. This selected time point produces a one-dimensional image resulting in real-time, live observation of anatomy. Ultrasound used during functional movement can be referred to as dynamic ultrasound; this is feasible and reliable with the use of a linear transducer, elastic belt, and foam block to secure consistent transducer placement. The lateral abdominal wall is commonly investigated using ultrasound due to the overlapping nature of the muscles. Surface electromyography (sEMG) can complement M-mode ultrasound imaging because it measures the electrical representation of muscle activation. There is minimal evidence using M-mode ultrasound and sEMG simultaneously during core exercise. Exercises that challenge the core musculature involve both isometric holds (e.g., side plank), as well as oscillatory extremity movements (e.g., dead bug). In this study, both instruments will be used simultaneously to measure core muscle function during exercise. Ultrasound measurements will be obtained using a linear transducer and ultrasound unit, and sEMG measurements will be acquired from a wireless sEMG system. To make comparisons between participants and exercises, normalization methods using static, exercise starting positions for both instruments will be used. An activation ratio will be used for ultrasound and calculated by dividing the contracted thickness (thickness during a time point of exercise) by the rested (starting position) thickness. Muscle thickness will be measured in centimeters from the superior inferior fascial border to inferior superior fascial border. These methods aim to offer an innovative and practical measurement of muscle function with M-mode ultrasound and sEMG during core endurance exercises.

This protocol uses motion mode ultrasound and surface electromyography simultaneously to measure muscle function of the core. Muscle thickness and activation of the local stabilizers (e.g., transverse abdominis, internal oblique) and global movers (e.g., external oblique) is achievable during specific time points of the side plank and dead bug exercises.

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured ...

Assessing Pulmonary Alveolar-Capillary Reserve During Exercise

Dual Test Gas Pulmonary Diffusing Capacity Measurement During Exercise in Humans Using the Single-Breath Method

The combined single-breath measurement of the diffusing capacity of carbon monoxide (DL,CO) and nitric oxide (DL,NO) is a useful technique to measure pulmonary alveolar-capillary reserve in both healthy and patient populations. The measurement provides an estimate of the participant&#39;s ability to recruit and distend pulmonary capillaries. The method has recently been reported to exhibit a high test-retest reliability in healthy volunteers during exercise of light to moderate intensity. Of note, this technique permits up to 12 repeated maneuvers and only requires a single breath with a relatively short breath-hold time of 5 s. Representative data are provided showing the gradual changes in DL,NO and DL,CO from rest to exercise at increasing intensities&#160;of up to 60% of maximal workload. The measurement of diffusing capacity and evaluation of alveolar-capillary reserve is a useful tool to evaluate the lung&#39;s ability to respond to exercise both in the healthy population as well as in patient populations such as those with chronic lung disease.

Author Spotlight: Integrating Alveolar-Capillary Reserve Measurements in Exercise Adaptation and Therapeutic Strategies

This protocol presents a method to assess pulmonary alveolar-capillary reserve measured by combined single-breath measurement of the diffusing capacity to carbon monoxide (DL,CO) and nitric oxide (DL,NO) during exercise. Assumptions and recommendations for using the technique during exercise form the foundation of this article.

The combined single-breath measurement of the diffusing capacity of carbon monoxide (DL,CO) and nitric oxide (DL,NO) is a useful technique to measure ...

Rehabilitation Treatment Plan for ACLR Patients

Early Weight-Bearing Rehabilitation Protocol After Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) injury is one of the common sports injuries. Anterior cruciate ligament reconstruction (ACLR) is the mainstream treatment for ACL injury, aiming to regain normal anatomical structure and stability of the knee joint and promote the patient's return to sports. Under the guidance of the concept of enhanced recovery after surgery, early weight-bearing rehabilitation (EWB) is an important factor affecting patient function and quality of life. However, there is no consensus on whether EWB rehabilitation can be performed after ACL surgery. 
This study aims to explore the safety and feasibility of EWB after ACL surgery. The study implemented a gradual EWB rehabilitation program in the experimental group, including weight-shifting training, balance training, and gait training on the affected lower limb, and assessed wound healing and stability of the knee joint. The study found that EWB after ACLR is safe and feasible. EWB rehabilitation not only does not pose a negative effect on the patient's knee pain, swelling, wound healing, and stability, but also helps to improve knee active flexion and quality of life faster and better. The EWB program in this study is simple, safe, and effective, and it provides strong theoretical guidance and practical demonstration for accelerated rehabilitation after ACLR.

Author Spotlight: Implementing the Enhanced Recovery After Surgery Concept in Rehabilitation Following Anterior Cruciate Ligament Reconstruction

Based on the safety and feasibility, this article presents an early weight-bearing rehabilitation protocol after anterior cruciate ligament reconstruction. The protocol is clear and easy to operate, which is helpful to promote its use in clinical practice and accelerate the functional recovery of patients.

Anterior cruciate ligament (ACL) injury is one of the common sports injuries. Anterior cruciate ligament reconstruction (ACLR) is the mainstream treatment ...