Professional Education

  • Doctor of Philosophy, Brown University (2015)
  • Bachelor of Arts, Brown University (2008)

Stanford Advisors

All Publications

  • Changes in Local Bone Density in Early Thumb Carpometacarpal Joint Osteoarthritis. The Journal of hand surgery Schreiber, J. J., McQuillan, T. J., Halilaj, E., Crisco, J. J., Weiss, A. P., Patel, T., Kenney, D., Ladd, A. L. 2017


    Thumb carpometacarpal (CMC) osteoarthritis (OA) represents a major source of functional morbidity. The effects of early CMC OA on loading and use patterns potentially lead to changes in local bone density and microarchitecture. Hounsfield units (HU), a quantitative attenuation coefficient obtained from computed tomography (CT) scans, have been shown to be a reliable marker of bone density. We hypothesized that early CMC OA is associated with lower local bone density about the CMC joint as assessed by HU.We examined HU units from CT scans in 23 asymptomatic subjects and 91 patients with early CMC OA. The HU measurements were obtained within cancellous portions of the trapezium, capitate, first and third metacarpal bases, and distal radius. Linear regression models, with age and sex included as covariates, were used to assess the relationship between CMC OA and HU values at each anatomical site.Early OA patients had significantly lower HU than asymptomatic subjects within the trapezium (mean, 377 HU vs 436 HU) and first metacarpal bases (265 HU vs 324 HU). No significant group differences were noted at the capitate, third metacarpal, or distal radius. Male sex and younger age were associated with significantly higher HU at all the anatomical sites, except the first metacarpal base, where age had no significant effect.Subjects presenting with early CMC OA had significantly lower bone density as assessed with HU at the thumb CMC joint (trapezium and first metacarpal base). Early thumb CMC OA and discomfort may lead to diminished loading across the basal joint, producing focal disuse osteopenia. These findings in symptomatic early arthritis suggest a relationship between symptoms, functional use of the CMC joint, and local bone density.Diagnostic II.

    View details for DOI 10.1016/j.jhsa.2017.09.004

    View details for PubMedID 29029863

  • Early osteoarthritis of the trapeziometacarpal joint is not associated with joint instability during typical isometric loading. Journal of orthopaedic research Halilaj, E., Moore, D. C., Patel, T. K., Ladd, A. L., Weiss, A. C., Crisco, J. J. 2015; 33 (11): 1639-1645


    The saddle-shaped trapeziometacarpal (TMC) joint contributes importantly to the function of the human thumb. A balance between mobility and stability is essential in this joint, which experiences high loads and is prone to osteoarthritis (OA). Since instability is considered a risk factor for TMC OA, we assessed TMC joint instability during the execution of three isometric functional tasks (key pinch, jar grasp, and jar twist) in 76 patients with early TMC OA and 44 asymptomatic controls. Computed tomography images were acquired while subjects held their hands relaxed and while they applied 80% of their maximum effort for each task. Six degree-of-freedom rigid body kinematics of the metacarpal with respect to the trapezium from the unloaded to the loaded task positions were computed in terms of a TMC joint coordinate system. Joint instability was expressed as a function of the metacarpal translation and the applied force. We found that the TMC joint was more unstable during a key pinch task than during a jar grasp or a jar twist task. Sex, age, and early OA did not have an effect on TMC joint instability, suggesting that instability during these three tasks is not a predisposing factor in TMC OA. © 2015 Orthopaedic Research Society. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1002/jor.22936

    View details for PubMedID 25941135

  • Older asymptomatic women exhibit patterns of thumb carpometacarpal joint space narrowing that precede changes associated with early osteoarthritis JOURNAL OF BIOMECHANICS Halilaj, E., Moore, D. C., Patel, T. K., Laidlaw, D. H., Ladd, A. L., Weiss, A. C., Crisco, J. J. 2015; 48 (13): 3634-3640
  • In vivo recruitment patterns in the anterior oblique and dorsoradial ligaments of the first carpometacarpal joint JOURNAL OF BIOMECHANICS Halilaj, E., Rainbow, M. J., Moore, D. C., Laidlaw, D. H., Weiss, A. C., Ladd, A. L., Crisco, J. J. 2015; 48 (10): 1893-1898


    The anterior oblique ligament (AOL) and the dorsoradial ligament (DRL) are both regarded as mechanical stabilizers of the thumb carpometacarpal (CMC) joint, which in older women is often affected by osteoarthritis. Inferences on the potential relationship of these ligaments to joint pathomechanics are based on clinical experience and studies of cadaveric tissue, but their functions has been studied sparsely in vivo. The purpose of this study was to gain insight into the functions of the AOL and DRL using in vivo joint kinematics data. The thumbs of 44 healthy subjects were imaged with a clinical computed tomography scanner in functional-task and thumb range-of-motion positions. The origins and insertion sites of the AOL and the DRL were identified on the three-dimensional bone models and each ligament was modeled as a set of three fibers whose lengths were the minimum distances between insertion sites. Ligament recruitment, which represented ligament length as a percentage of the maximum length across the scanned positions, was computed for each position and related to joint posture. Mean AOL recruitment was lower than 91% across the CMC range of motion, whereas mean DRL recruitment was generally higher than 91% in abduction and flexion. Under the assumption that ligaments do not strain by more than 10% physiologically, our findings of mean ligament recruitments across the CMC range of motion indicate that the AOL is likely slack during most physiological positions, whereas the DRL may be taut and therefore support the joint in positions of CMC joint abduction and flexion.

    View details for DOI 10.1016/j.jbiomech.2015.04.028

    View details for Web of Science ID 000358459800029

  • In Vivo kinematics of the trapeziometacarpal joint during thumb extension-flexion and abduction-adduction. journal of hand surgery Crisco, J. J., Halilaj, E., Moore, D. C., Patel, T., Weiss, A. C., Ladd, A. L. 2015; 40 (2): 289-296


    The primary aim of this study was to determine whether the in vivo kinematics of the trapeziometacarpal (TMC) joint differ as a function of age and sex during thumb extension-flexion (Ex-Fl) and abduction-adduction (Ab-Ad) motions.The hands and wrists of 44 subjects (10 men and 11 women with ages 18-35 y and 10 men and 13 women with ages 40-75 y) with no symptoms or signs of TMC joint pathology were imaged with computed tomography during thumb extension, flexion, abduction, and adduction. The kinematics of the TMC joint were computed and compared across direction, age, and sex.We found no significant effects of age or sex, after normalizing for size, in any of the kinematic parameters. The Ex-Fl and Ab-Ad rotation axes did not intersect, and both were oriented obliquely to the saddle-shaped anatomy of the TMC articulation. The Ex-Fl axis was located in the trapezium and the Ab-Ad axis was located in the metacarpal. Metacarpal translation and internal rotation occurred primarily during Ex-Fl.Our findings indicate that normal TMC joint kinematics are similar in males and females, regardless of age, and that the primary rotation axes are nonorthogonal and nonintersecting. In contrast to previous studies, we found Ex-Fl and Ab-Ad to be coupled with internal-external rotation and translation. Specifically, internal rotation and ulnar translation were coupled with flexion, indicating a potential stabilizing screw-home mechanism.The treatment of TMC pathology and arthroplasty design require a detailed and accurate understanding of TMC function. This study confirms the complexity of TMC kinematics and describes metacarpal translation coupled with internal rotation during Ex-Fl, which may explain some of the limitations of current treatment strategies and should help improve implant designs.

    View details for DOI 10.1016/j.jhsa.2014.10.062

    View details for PubMedID 25542440

  • The Envelope of Physiological Motion of the First Carpometacarpal Joint. Journal of biomechanical engineering Crisco, J. J., Patel, T., Halilaj, E., Moore, D. C. 2015; 137 (10)


    Much of the hand's functional capacity is due to the versatility of the motions at the thumb carpometacarpal (CMC) joint, which are presently incompletely defined. The aim of this study was to develop a mathematical model to completely describe the envelope of physiological motion of the thumb CMC joint and then to examine if there were differences in the kinematic envelope between women and men. In vivo kinematics of the first metacarpal with respect to the trapezium were computed from computed tomography (CT) volume images of 44 subjects (20M, 24F, 40.3 ± 17.7 yr) with no signs of CMC joint pathology. Kinematics of the first metacarpal were described with respect to the trapezium using helical axis of motion (HAM) variables and then modeled with discrete Fourier analysis. Each HAM variable was fit in a cyclic domain as a function of screw axis orientation in the trapezial articular plane; the RMSE of the fits was 14.5 deg, 1.4 mm, and 0.8 mm for the elevation, location, and translation, respectively. After normalizing for the larger bone size in men, no differences in the kinematic variables between sexes could be identified. Analysis of the kinematic data also revealed notable coupling of the primary rotations of the thumb with translation and internal and external rotations. This study advances our basic understanding of thumb CMC joint function and provides a complete description of the CMC joint for incorporation into future models of hand function. From a clinical perspective, our findings provide a basis for evaluating CMC pathology, especially the mechanically mediated aspects of osteoarthritis (OA), and should be used to inform artificial joint design, where accurate replication of kinematics is essential for long-term success.

    View details for DOI 10.1115/1.4031117

    View details for PubMedID 26201612

  • Is early osteoarthritis associated with differences in joint congruence? JOURNAL OF BIOMECHANICS Conconi, M., Halilaj, E., Castelli, V. P., Crisco, J. J. 2014; 47 (16): 3787-3793


    Previous studies suggest that osteoarthritis (OA) is related to abnormal or excessive articular contact stress. The peak pressure resulting from an applied load is determined by many factors, among which is shape and relative position and orientation of the articulating surfaces or, referring to a more common nomenclature, joint congruence. It has been hypothesized that anatomical differences may be among the causes of OA. Individuals with less congruent joints would likely develop higher peak pressure and thus would be more exposed to the risk of OA onset. The aim of this work was to determine if the congruence of the first carpometacarpal (CMC) joint differs with the early onset of OA or with sex, as the female population has a higher incidence of OA. 59 without and 38 with early OA were CT-scanned with their dominant or arthritic hand in a neutral configuration. The proposed measure of joint congruence is both shape and size dependent. The correlation of joint congruence with pathology and sex was analyzed both before and after normalization for joint size. We found a significant correlation between joint congruence and sex due to the sex-related differences in size. The observed correlation disappeared after normalization. Although joint congruence increased with size, it did not correlate significantly with the onset of early OA. Differences in joint congruence in this population may not be a primary cause of OA onset or predisposition, at least for the CMC joint.

    View details for DOI 10.1016/j.jbiomech.2014.10.030

    View details for Web of Science ID 000347864900001

    View details for PubMedID 25468667

  • Polar Histograms of Curvature for Quantifying Skeletal Joint Shape and Congruence JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME Halilaj, E., Laidlaw, D. H., Moore, D. C., Crisco, J. J. 2014; 136 (9)


    The effect of articular joint shape and congruence on kinematics, contact stress, and the natural progression of joint disease continue to be a topic of interest in the orthopedic biomechanics literature. Currently, the most widely used metrics of assessing skeletal joint shape and congruence are based on average principal curvatures across the articular surfaces. Here we propose a method for comparing articular joint shape and quantifying joint congruence based on three-dimensional (3D) histograms of curvature--shape descriptors that preserve spatial information. Illustrated by experimental results from the trapeziometacarpal joint, this method could help unveil the interrelations between joint shape and function and provide much needed insight for the high incidence of osteoarthritis (OA)--a mechanically mediated disease whose onset has been hypothesized to be precipitated by joint incongruity.

    View details for DOI 10.1115/1.4027938

    View details for Web of Science ID 000340617700013

    View details for PubMedID 24976300

  • The morphology of the thumb carpometacarpal joint does not differ between men and women, but changes with aging and early osteoarthritis. Journal of biomechanics Halilaj, E., Moore, D. C., Laidlaw, D. H., Got, C. J., Weiss, A. C., Ladd, A. L., Crisco, J. J. 2014; 47 (11): 2709-2714


    The high prevalence of thumb carpometacarpal (CMC) joint osteoarthritis (OA) in women has been previously linked to the articular morphology of the trapezium. Studies report conflicting results on how the articular shapes of male and female trapezia compare to one another, however, mainly because their findings are based on data from older cadaveric specimens. The purpose of this in vivo study was to dissociate the effect of sex from that of aging and early OA by using cohorts of healthy young and healthy older subjects, as well as patients with early stage OA. Computed tomography scans from 68 healthy subjects and 87 arthritic subjects were used to obtain 3-D bone models. The trapezial and metacarpal articular surfaces were manually delineated on scaled bone models and compared between sex, age, and health groups by using polar histograms of curvature and average curvatures. We found no sex-related differences, but significant age-group and health-group differences, in the articular surfaces of both bones. Older healthy subjects had higher curvature in the concave and lower curvature in the convex directions of both the trapezial and metacarpal saddles than healthy young subjects. Subjects with early OA had significantly different metacarpal and trapezial articular shapes from healthy subjects of the same age group. These findings suggest that aging and OA affect the articular shape of the CMC joint, but that, in contrast to previously held beliefs, inherent sex differences are not responsible for the higher incidence of CMC OA in women.

    View details for DOI 10.1016/j.jbiomech.2014.05.005

    View details for PubMedID 24909332

  • In Vivo Kinematics of the Thumb Carpometacarpal Joint During Three Isometric Functional Tasks CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Halilaj, E., Rainbow, M. J., Got, C., Schwartz, J. B., Moore, D. C., Weiss, A. C., Ladd, A. L., Crisco, J. J. 2014; 472 (4): 1114-1122


    The thumb carpometacarpal (CMC) joint is often affected by osteoarthritis--a mechanically mediated disease. Pathomechanics of the CMC joint, however, are not thoroughly understood due to a paucity of in vivo data.We documented normal, in vivo CMC joint kinematics during isometric functional tasks. We hypothesized there would be motion of the CMC joint during these tasks and that this motion would differ with sex and age group. We also sought to determine whether the rotations at the CMC joint were coupled and whether the trapezium moved with respect to the third metacarpal.Forty-six asymptomatic subjects were CT-scanned in a neutral position and during three functional tasks (key pinch, jar grasp, jar twist), in an unloaded and a loaded position. Kinematics of the first metacarpal, third metacarpal, and the trapezium were then computed.Significant motion was identified in the CMC joint during all tasks. Sex did not have an effect on CMC joint kinematics. Motion patterns differed with age group, but these differences were not systematic across the tasks. Rotation at the CMC joint was generally coupled and posture of the trapezium relative to the third metacarpal changed significantly with thumb position.The healthy CMC joint is relatively stable during key pinch, jar grasp, and jar twist tasks, despite sex and age group.Our findings indicate that directionally coupled motion patterns in the CMC joint, which lead to a specific loading profile, are similar in men and women. These patterns, in addition to other, nonkinematic influences, especially in the female population, may contribute to the pathomechanics of the osteoarthritic joint.

    View details for DOI 10.1007/s11999-013-3063-y

    View details for Web of Science ID 000332576400012

    View details for PubMedID 23681597

  • How Do Sex, Age, and Osteoarthritis Affect Cartilage Thickness at the Thumb Carpometacarpal Joint? Insights from Subject-Specific Cartilage Modeling Bio-Imaging and Visualization for Patient-Customized Simulations Halilaj, E., Laidlaw, D. H., Moore, D. C., Crisco, J. J. 2014: 103–111
  • Computed Tomography Image-Based Kinematic Analysis: An Overview Handbook of Imaging in Biological Mechanics Moore, D. C., Halilaj, E., Patel, T. K., Crisco, J. J. CRC Press. 2014: 115–126

    View details for DOI 10.1201/b17566-14

  • Thumb carpometacarpal joint congruence during functional tasks and thumb range-of-motion activities. Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference Halilaj, E., Moore, D. C., Patel, T. K., Laidlaw, D. H., Ladd, A. L., Weiss, A. C., Crisco, J. J. 2014; 2014: 4354-4357


    Joint incongruity is often cited as a possible etiological factor for the high incidence of thumb carpometacarpal (CMC) joint osteoarthritis (OA) in older women. There is evidence suggesting that biomechanics plays a role in CMC OA progression, but little is known about how CMC joint congruence, specifically, differs among different cohorts. The purpose of this in vivo study was to determine if CMC joint congruence differs with sex, age, and early stage OA for different thumb positions. Using CT data from 155 subjects and a congruence metric that is based on both articular morphology and joint posture, we did not find any differences in CMC joint congruence with sex or age group, but found that patients in the early stages of OA exhibit lower congruence than healthy subjects of the same age group.

    View details for DOI 10.1109/EMBC.2014.6944588

    View details for PubMedID 25570956

  • A thumb carpometacarpal joint coordinate system based on articular surface geometry JOURNAL OF BIOMECHANICS Halilaj, E., Rainbow, M. J., Got, C. J., Moore, D. C., Crisco, J. J. 2013; 46 (5): 1031-1034


    The thumb carpometacarpal (CMC) joint is a saddle-shaped articulation whose in vivo kinematics can be explored more accurately with computed tomography (CT) imaging methods than with previously used skin-based marker systems. These CT-based methods permit a detailed analysis of the morphology of the joint, and thus the prominent saddle geometry can be used to define a coordinate system that is inherently aligned with the primary directions of motion at the joint. The purpose of this study was to develop a CMC joint coordinate systems that is based on the computed principal directions of curvature on the trapezium and the first metacarpal. We evaluated the new coordinate system using bone surface models segmented from the CT scans of 24 healthy subjects. An analysis of sensitivity to the manual selection of articular surfaces resulted in mean orientation differences of 0.7±0.7° and mean location differences of 0.2±0.1mm. Inter-subject variability, which mostly emanates from anatomical differences, was evaluated with whole bone registration and resulted in mean orientation differences of 3.1±2.7° and mean location differences of 0.9±0.5mm. The proposed joint coordinate system addresses concerns of repeatability associated with bony landmark identification and provides a robust platform for describing the complex kinematics of the CMC joint.

    View details for DOI 10.1016/j.jbiomech.2012.12.002

    View details for Web of Science ID 000316829700028

    View details for PubMedID 23357698