In vivo kinematics of the first carpometacarpal joint after trapezectomy

Disease severity versus pain severity: Range of motion differences during single- and multiplanar tasks in women with carpometacarpal osteoarthritis

In carpometacarpal osteoarthritis (CMC OA) of the thumb, to what extent treatments should be directed by radiographic disease severity versus pain-based indicators remains an open question. To address this gap, this study investigated the relative impact of disease severity and pain severity on the range of motion in participants with CMC OA. We hypothesized larger differences would exist between extremes in the pain severity cohort than the disease severity cohort, suggesting pain modulates movement to a greater extent than joint degradation. Thirty-one female participants (64.6 ± 10.9 years) were grouped as symptomatic or asymptomatic (pain severity cohort) and early stage OA or end-stage OA (disease severity cohort) using radiographs and questionnaires. Kinematics were measured during single-planar and multiplanar range of motion tasks. Joint angle differences between groups were statistically compared. Differences in self-reported pain, function, and disability were evident in both participant cohorts. Notably, substantial distinctions emerged exclusively during multiplanar tasks, with a greater prevalence in the disease severity cohort compared to the pain severity cohort. Participants with end-stage OA also exhibited similar overall area covered during circumduction in comparison to those with early-stage OA, despite having a decreased range of motion at the CMC joint. The study underscores the importance of assessing multiplanar tasks, potentially leading to earlier identification of CMC OA. While movement compensations such as employing the distal thumb joints over the CMC joint were observed, delving deeper into the interplay between pain and movement could yield greater insight into the underlying factors steering these compensatory mechanisms.

Anatomy and Biomechanics of the Thumb Carpometacarpal Joint

This review discusses the anatomy and biomechanics of the thumb carpometacarpal (CMC) joint. This articulation between the trapezium and first metacarpal is integral for opposition and other complex movements necessary for pinch and grasp maneuvers. Fortunately, this joint is well equipped to handle the extreme forces imposed by these movements, as it is stabilized by an elaborate arrangement of ligaments and muscles. Without this stability, thumb subluxation would occur with loading during pinch and grasp, and human prehension would be impossible. Understanding the interactions occurring within this joint is essential for adequately treating pathology arising in this crucial joint.

Anatomy and biomechanics of healthy and arthritic trapeziometacarpal joints

Understanding the biomechanics of the trapeziometacarpal (TMC) or first carpometacarpal (CMC1) joint, the pathophysiology of basal thumb arthritis, the design and performance of surgical procedures require a solid anatomical basis. This review of literature summarizes the most recent data on the descriptive, functional, and comparative anatomy of healthy and arthritic TMC joints.

A method for defining carpometacarpal joint kinematics from three-dimensional rotations of the metacarpal bones captured in vivo using computed tomography

The carpometacarpal (CMC) joints of the hand facilitate motion of the metacarpals and are critical for functional tasks, especially tasks involving precision grasping. Despite their importance, only limited data describing metacarpal kinematics exist. In this short communication, we quantified in vivo metacarpal kinematics from a single subject and used these data to develop the kinematic functions necessary to add rotational degrees of freedom at the CMC joints to a biomechanical model of the hand. Computed tomography (CT) was used to capture three-dimensional rotations of the metacarpal bones of the ring and little fingers of the subject in seven different static postures, chosen to position the fourth and fifth metacarpals throughout a functional range of motion. The CT images were manually segmented, yielding digital surface representations of the metacarpals in each posture. From the surfaces, principal axes of rotation were defined by calculating orthonormal bases of the surface vertices. The three-dimensional rotations of the fourth and fifth metacarpals were quantified in each posture about their principal axes, relative to a designated reference posture. For both metacarpals, ranges of rotations were computed about the principal axes across all seven postures. From the processed data, single axes and angles were calculated that were equivalent to the three dimensional ranges of motion. Finally, kinematic functions were defined that enabled modeling of the formation of a metacarpal arch by movement of the fourth and fifth CMC joints as one degree of freedom, coupled to a single generalized coordinate.