John J Elias

John J Elias
Cleveland Clinic Akron General

PhD

About

95
Publications
13,001
Reads
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2,996
Citations
Citations since 2017
24 Research Items
1226 Citations
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
Additional affiliations
June 2008 - present
Cleveland Clinic Akron General
Position
  • Senior Researcher
December 2001 - June 2008
Medical Education and Research Institute of Colorado
Position
  • Laboratory Director
July 1995 - December 2001
Johns Hopkins University
Position
  • Post-doc/Instructor/Assistant Professor
Education
July 1995 - July 1997
Johns Hopkins University
Field of study
  • Orthopaedic Biomechanics
August 1989 - August 1994
Rensselaer Polytechnic Institute
Field of study
  • Biomedical Engineering
August 1985 - May 1989
University of Notre Dame
Field of study
  • Mechanical Engineering

Publications

Publications (95)
Article
Knee squatting was simulated to characterize the influence of medial patellofemoral ligament (MPFL) reconstruction on patellar tracking and contact pressures for knees with mild patella alta (Caton-Deschamps index = 1.3-1.4). Eight computational models represented knees in the pre-operative condition and following MPFL reconstruction. MPFL reconstr...
Article
Introduction: Pathologic anatomy is a primary factor contributing to re-dislocation of the patella following reconstruction of the medial patellofemoral ligament (MPFL). A pivot landing was simulated following MPFL reconstruction, with the hypothesis that position of the tibial tuberosity, depth of the trochlear groove, and height of the patella ar...
Article
Magnetic resonance imaging (MRI) is a valuable tool for evaluating musculoskeletal disease as it offers a range of image contrasts that are sensitive to underlying tissue biochemical composition and microstructure. Although MRI has the ability to provide high-resolution, information-rich images suitable for musculoskeletal applications, most MRI ut...
Article
Full-text available
Objective: The study was performed to evaluate cartilage within the knee following a first-time patellar dislocation, using elevated MRI-based T1ρ relaxation times as an indicator of low proteoglycan concentration. The hypothesis is that MRI-based T1ρ relaxation times for patellofemoral and tibiofemoral cartilage are significantly longer for knees...
Chapter
Patellofemoral biomechanics are influenced by the anatomy of the patella and trochlear groove and the forces applied to the patella through the quadriceps muscles, patellar tendon, medial and lateral ligaments, and retinacular structures. The normal valgus orientation of the knee causes a lateral orientation in the resultant force acting on the pat...
Article
Groove-deepening trochleoplasty is performed to restore patellar stability by increasing the lateral constraint applied to the patella by the trochlear groove. Multibody dynamic simulation of knee function was used to characterize the influence of groove-deepening trochleoplasty on patellar tracking and patellofemoral contact pressures. Computation...
Article
Full-text available
Background Patella alta reduces articular constraints acting on the patella from the trochlear groove with the knee extended. The current study was performed to address how patella alta alters the influence of tibial tuberosity position and trochlear depth on patellar tracking in patients being treated for patellar instability. Methods Fifteen sub...
Article
Background The onset and progression of patellofemoral osteoarthritis (OA) has been linked to alterations in cartilage stress—a potential precursor to pain and subsequent cartilage degradation. A lack in quantitative tools for objectively evaluating patellofemoral joint contact stress limits our understanding of pathomechanics associated with OA....
Article
Full-text available
Introduction Hip fractures are a significant economic burden to our healthcare system. As there have been efforts made to create an alternative payment model for hip fracture care, it will be imperative to risk-stratify reimbursement for these medically comorbid patients. We hypothesized that patients readmitted to the hospital within 90 days would...
Article
Full-text available
Medial patellofemoral ligament (MPFL) reconstruction is currently the primary surgical procedure for treating recurrent lateral patellar instability. The understanding of graft function has largely been based on studies performed with normal knees. The current study was performed to characterize graft function following MPFL reconstruction, focusin...
Article
Full-text available
Background: Medial patellofemoral ligament reconstruction and tibial tuberosity anteromedialization are common treatment options for recurrent lateral patellar instability, although ligament reconstruction is not commonly applied to knees with lateral malalignment. Methods: Multibody dynamic simulation was used to assess knee function following...
Article
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Background: The study focuses on the influence of trochlear dysplasia on patellar tracking related to patellar instability. Methods: Knee extension against gravity and dual-limb squatting were simulated with seven models representing knees being treated for recurrent instability. Trochlear depth was altered to represent lateral trochlear inclina...
Article
Background: Our objective was to describe a measurement to assess sagittal tibial tuberosity (TT)-trochlear groove (TG) distance and to compare this between asymptomatic (control) patients and patients with symptomatic patellar instability. Methods: We compared static CT images of 22 fully extended knees of patients with symptomatic patellar ins...
Article
Full-text available
Quantifying the complex loads at the patellofemoral joint (PFJ) is vital to understanding the development of PFJ pain and osteoarthritis. Discrete element analysis (DEA) is a computationally efficient method to estimate cartilage contact stresses with potential application at the PFJ to better understand PFJ mechanics. The current study validated a...
Article
Full-text available
PurposeGraft tensioning during medial patellofemoral ligament (MPFL) reconstruction typically allows for lateral patellar translation within the trochlear groove. Computational simulation was performed to relate the allowed patellar translation to patellofemoral kinematics and contact pressures. Methods Multibody dynamic simulation models were deve...
Article
Full-text available
Tibial rotations with respect to the femur influence measurements used to assess the lateral position of the tibial tuberosity. This study utilized computational modeling to quantify how the tibial tuberosity to trochlear groove (TT-TG) and tibial tuberosity to posterior cruciate ligament attachment (TT-PCL) distances vary with tibial internal/exte...
Article
Full-text available
The study utilizes dynamic simulation of knee function to determine how tibial tuberosity medialization and anteromedialization influence patellar tracking and contact pressures for knees with patellar instability. Dual limb squatting was simulated with six multibody dynamic simulation models representing knees being treated for patellar instabilit...
Article
Full-text available
Purpose Locked symphyseal plates are utilized to provide higher levels of construct stiffness than non-locked plates. The current biomechanical study was performed to compare stiffness at the pubic symphysis between locked and non-locked plating systems. Methods Synthetic models were utilized to represent injury to the pelvis and symphyseal plating...
Article
Full-text available
Background: Continued patellar instability can occur following medial patellofemoral ligament (MPFL) reconstruction. Computational simulation of function was used to investigate the influence of the lateral position of the tibial tuberosity, trochlear dysplasia and patella alta on lateral patellar tracking following MPFL reconstruction. Methods:...
Chapter
The evaluation and treatment of patellofemoral disorders requires a thorough understanding of the multiple factors that can contribute to these conditions. Treatments should be individualized to address the specific anatomic or functional deficits of a patient, while taking care to avoid the commonly reported complications that can occur with these...
Article
Purpose The current study compares the strength of a previously studied technique for flexor tendon repair with barbed sutures to an experimental approach that aligns all the barbs to oppose distraction. Methods Twelve flexor tendons from cadaveric specimens were mechanically tested following repair of simulated zone II tendon injuries. Two repair...
Article
Full-text available
Biomechanical studies are commonly performed to evaluate the influence of medial patellofemoral ligament (MPFL) reconstruction and tibial tuberosity medialization on patellar tracking and patellofemoral contact pressures. The most common method is in vitro simulation of knee function, but computational simulation of knee function and computational...
Article
Full-text available
Background: This in vitro study evaluated the biomechanical benefit of adding spanning sutures to single-row rotator cuff repair. Methods: Mechanical testing was performed to evaluate 9 pairs of cadaveric shoulders with complete rotator cuff repairs, with a single-row technique used on one side and the suture spanning technique on the other. The...
Article
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Background: Medial patellofemoral ligament (MPFL) reconstruction is performed to prevent recurrent instability, but errors in femoral fixation can elevate graft tension. Hypothesis: Errors related to femoral fixation will overconstrain the patella and increase medial patellofemoral pressures. Study design: Controlled laboratory study. Methods...
Article
Background and purpose: The capillary index score (CIS) is based on the hypothesis that areas lacking capillary blush on pretreatment cerebral digital subtraction angiograms correspond to nonviable cerebral tissue. Methods: Pretreatment digital subtraction angiograms and post-treatment noncontrast enhanced computed tomographic scans from the MR...
Article
Purpose: Little has been reported on the relationship between patellar maltracking and instability. Patellar maltracking has been subjectively described with the "J sign" but is difficult to assess objectively using traditional imaging. Dynamic kinematic computed tomography (DKCT) allows dynamic assessment of the patellofemoral joint. DKCT was use...
Article
Full-text available
Background: The current study was performed to correlate anatomical parameters related to trochlear dysplasia, tibial tuberosity position, and patella alta with in vivo patellar tracking for subjects with recurrent patellar instability. Methods: Eight subjects with recurrent patellar instability that failed conservative treatment were evaluated...
Article
Purpose: To evaluate the role of tibial tuberosity-trochlear groove (TT-TG) distance in patellofemoral kinematics by retrospectively reviewing the dynamic computed tomography scans of patients with unilateral patellofemoral instability and comparing unstable and contralateral asymptomatic knees. Methods: We reviewed all dynamic computed tomograp...
Article
Full-text available
Due to recent results from clinical intra-arterial treatment for acute ischemic stroke (IAT-AIS) trials such as the Interventional Management of Stroke (IMS III), IAT-AIS and the merit of revascularization have been contested. Even though intra-arterial treatment (IAT) has been shown to improve revascularization rates, a corresponding increase in g...
Article
Until recently, acute ischemic stroke (AIS) trials have failed to show a benefit of endovascular therapy compared with standard therapy, leading some authors to recommend decreasing the time from ictus to revascularization to improve outcomes. We hypothesize that improving patient selection using the capillary index score (CIS) may also be a useful...
Article
The purpose of this study was to evaluate changes in tibial tuberosity-trochlear groove (TTTG) distance with knee flexion in patients with patellar instability and correlate it with patellar position. Patients with symptomatic patellar instability underwent dynamic kinematic computed tomography (CT) during a cycle of knee extension from flexion. Kn...
Article
Full-text available
The current strategy for intra-arterial treatment (IAT) of acute ischemic stroke focuses on minimizing time from ictus to revascularization and maximizing revascularization. Employing this strategy has yet to lead to improved rates of successful outcomes. However, the collateral blood supply likely plays a significant role in maintaining viable bra...
Article
Full-text available
The current study was performed to characterize the influence of patellar stabilization procedures on patellofemoral and tibiofemoral dynamic motion. Six knees were evaluated pre-operatively and 1 year or longer following stabilization via tibial tuberosity realignment, with simultaneous medial patellofemoral ligament reconstruction performed for f...
Article
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Periodic practice is needed for newly trained robotic surgeons to maintain skills during periods of robotic inactivity. The current study was performed to determine whether virtual robotic skill maintenance can serve as an adequate substitute for practice on a surgical robot. Eleven surgical residents with no prior robotic training were trained to...
Article
Purpose: To test the hypothesis that in patients with unilateral patellofemoral instability ( PI patellofemoral instability ), the contralateral asymptomatic joints have abnormal morphology and imaging features of osteoarthritis ( OA osteoarthritis ) at four-dimensional ( 4D four-dimensional ) computed tomography (CT). Materials and methods: The...
Article
Full-text available
Purpose The current study was performed to relate anatomical parameters to in vivo patellar tracking for pediatric patients with recurrent patellar instability. Methods Seven pediatric patients with recurrent patellar instability that failed conservative treatment were evaluated using computational reconstruction of in vivo patellofemoral functi...
Article
Full-text available
This study was performed to evaluate a dynamic multibody model developed to characterize the influence of tibial tuberosity realignment procedures on patellofemoral motion and loading. Computational models were created to represent four knees previously tested at 40°, 60°, and 80° of flexion with the tibial tuberosity in a lateral, medial and anter...
Article
Background and purpose: The Capillary Index Score (CIS) is a simple angiography-based scale for assessing viable tissue in the ischemic territory. We retrospectively applied it to Interventional Management of Stroke (IMS) trials I and II to evaluate the predictive value for good outcomes. Methods: CIS was calculated from pretreatment diagnostic...
Article
Full-text available
The study was performed to establish a level of practice needed for newly-trained residents to maintain robotic surgical skills during periods of robotic inactivity. Ten surgical residents were trained to a standardized level of robotic surgery proficiency with inanimate models. At the end of two, four and six weeks, the residents practiced with th...
Article
Full-text available
A finite element analysis (FEA) modeling technique has been developed to characterize how varying the orientation of the patellar tendon influences the patellofemoral pressure distribution. To evaluate the accuracy of the technique, models were created from MRI images to represent five knees that were previously tested in vitro to determine the inf...
Article
Full-text available
The current study was performed to determine the strength and rigidity of the intact flexor digitorum profundus (FDP) tendon attachment and compare the rigidity at the attachment site to the rigidity within a more proximal part of the tendon. Eight cadaveric index fingers were tested to failure of the FDP tendon. Lines were drawn on each tendon wit...
Chapter
Computational models of the patellofemoral joint are commonly utilized to characterize patellofemoral kinematics, areas of contact, and pressure applied to patellofemoral cartilage. Computational models can provide enhanced display of patellofemoral kinematics by graphically recreating motions performed by subjects. The reconstructed motions are ty...
Article
Full-text available
Objectives For patients with recurrent patellofemoral instability, tibial tuberosity medialization is commonly performed to reduce the lateral force applied to the patella by the patellar tendon. Medialization also alters the force acting on the tibia, which could alter tibiofemoral kinematics. Several other procedures are advocated to treat patell...
Article
Full-text available
Background: The current study was performed to evaluate the accuracy of computational assessment of the influence of the orientation of the patellar tendon on the patellofemoral pressure distribution. Method of Approach: Computational models were created to represent eight knees previously tested at 40, 60 and 80 degrees of flexion to evaluate the...
Article
Full-text available
The hamstrings are considered stabilizers of the anterior cruciate ligament-deficient knee; however, anterior cruciate ligament injury primarily influences tibiofemoral kinematics near full extension, where the hamstrings have the least influence on kinematics. Ten knees were tested at multiple flexion angles in vitro to directly compare the influe...
Article
Full-text available
Anterior cruciate ligament (ACL) injury alters tibiofemoral contact during function, with a posterior shift of the point of contact on the tibia. An all-epiphyseal approach to ACL reconstruction is performed in pediatric patients to improve tibiofemoral contact without disturbing the physis. The hypothesis of the study is that all-epiphyseal ACL re...
Article
Full-text available
The study was performed to characterize the influence of tibial tuberosity realignment on the pressure applied to cartilage on the patella in the intact condition and with lesions on the lateral and medial facets. Ten knees were loaded in vitro through the quadriceps (586 N) and hamstrings (200 N) at 40°, 60°, and 80° of flexion while measuring pat...
Chapter
Computational models of the patellofemoral joint are commonly utilized to characterize patellofemoral kinematics, areas of contact, and pressure applied to patellofemoral cartilage. Computational models can provide enhanced display of patellofemoral kinematics by graphically recreating motions performed by subjects. The reconstructed motions are ty...
Article
Full-text available
Tibial tuberosity realignment surgery is performed to improve patellofemoral alignment, but it could also alter tibiofemoral kinematics. After tuberosity realignment in the malaligned knee, the reoriented patellar tendon will pull the tuberosity back toward the preoperative position, thereby altering tibiofemoral kinematics. Controlled laboratory s...
Article
Full-text available
Hamstrings loading has previously been shown to increase tibiofemoral posterior translation and external rotation, which could contribute to patellofemoral malalignment and elevated patellofemoral pressures. The current study characterizes the influence of forces applied by the hamstrings on patellofemoral kinematics and the pressure applied to pat...
Article
A study was performed to evaluate a computational model used to characterize the influence of vastus medialis obliquus (VMO) function on the patellofemoral pressure distribution. Ten knees were tested in vitro at 40 degrees, 60 degrees and 80 degrees of knee flexion with quadriceps loads applied to represent a normal VMO, and with the VMO force dec...
Article
The current study was performed to characterize how improving vastus medialis obliquus (VMO) function influences the pressure applied to patellofemoral cartilage. An additional focus was characterizing how lateral and medial cartilage lesions influence cartilage pressures. Ten knees were flexed to 40 degrees, 60 degrees, and 80 degrees in vitro, an...
Article
Full-text available
Hamstring tendon grafts used for anterior cruciate ligament reconstruction are preconditioned to reduce the influence of viscoelasticity on the stiffness and tension. Increasing the tension applied during preconditioning will decrease the loss of tension and stiffness due to viscoelasticity. Controlled laboratory study. Six quadruple-strand hamstri...
Article
Full-text available
Following anterior cruciate ligament reconstruction, grafts relax and warm from the temperature of the operating room to body temperature. The current study compared graft tension and stiffness between patella tendon and hamstring tendon grafts. Six quadruple strand hamstring tendon grafts and six patella tendon grafts were preconditioned and loade...
Article
A modified Boyd-Anderson 2-incision approach is commonly used to repair the distal biceps tendon after avulsion from the radial tuberosity. Using suture anchors for fixation instead of a bone trough simplifies the procedure. This retrospective study enrolled 32 patients who underwent surgical repair of the distal biceps tendon with a 2-incision app...
Article
This study was performed to evaluate the efficacy of interscalene regional blocks and infusion pumps for postoperative pain control after arthroscopic subacromial decompression with or without arthroscopic rotator cuff repair. Seventy-six patients were included in the prospective study. Participants were randomized into 4 treatment groups: (1) inte...
Article
Computational modeling is commonly used in all engineering disciplines to represent complex systems. A computational model of the patellofemoral joint is a graphical representation of joint anatomy that can be manipulated to simulate knee function. Current models are typically reconstructed from magnetic resonance imaging scans of knees. Force vect...
Article
Full-text available
The influence of reconstruction of the medial patellofemoral ligament on the patellofemoral force and pressure distributions has not yet been investigated. Technical errors can cause tension to develop within a reconstructed medial patellofemoral ligament, which will adversely alter the normal patellofemoral force distribution by increasing the loa...
Article
Hamstring tendon grafts used for anterior cruciate ligament reconstruction are typically harvested early in the surgical procedure and are preconditioned prior to reimplantation. Postoperatively, the grafts undergo stress relaxation and warm from the temperature of the operating room to body temperature. The hypothesis of this study was that the te...
Article
This study quantified the torsional resistance provided by locking plates and angled blade plates used to stabilize proximal humeral fractures. Three-part proximal humeral fractures were created in 6 pairs of cadaveric humeri. One specimen of each pair was reconstructed with a proximal humeral locking plate, whereas the other specimen was reconstru...
Article
EMG analysis has indicated that the vastus lateralis and vastus medialis contribute less to the quadriceps moment during knee extension than the physiological cross-sectional areas (PCSA's) of the muscles indicate. Both PCSA- and EMG-based quadriceps force distributions were utilized while computationally simulating knee extension. For both distrib...
Article
Anatomical reconstruction of a ruptured lateral collateral ligament using allograft tissue secured within the fibular head with an interference screw has been described. Interference fixation at the fibular head does not reproduce the strength of the intact ligament. Controlled laboratory study. Ten intact lateral collateral ligaments were tested t...
Article
Full-text available
Due to wide variations in acetabular structure of individuals with hip dysplasia, the measurement of the acetabular orientation may not be sufficient to predict the joint loading and pressure distribution across the joint. Addition of mechanical analysis to preoperative planning, therefore, has the potential to improve the clinical outcome. We anal...
Article
Extensor mechanism procedures that decrease the lateral component of the patellar tendon or quadriceps force acting on the patella do not consistently reduce pain. Patellofemoral treatments do not consistently decrease patellofemoral pressures because of variations in the moments acting on the patella. Computer simulation study. Computational model...
Article
One possible cause of patellofemoral pain syndrome is excessive lateral force acting on the patella. Although several treatment methods focus on decreasing the lateral force acting on the patella, the relationship between the lateral force and the patellofemoral contact pressure distribution is unclear. A computational model has been developed to d...
Article
Although the Q-angle is routinely measured, the relationship between the Q-angle and the lateral component of the quadriceps force acting on the patella is unknown. Five cadaver knees were flexed on a knee simulator with a normal Q-angle, and flexed after increasing and decreasing the Q-angle by shifting the quadriceps origin laterally and medially...