Research Summary
Research topic: Researching movement patterns performed by the thumb carpal metacarpal (CMC) joint to learn if they differ between women with and without osteoarthritis, and if differences in joint load or spacing are connected to severity of osteoarthritis.
Research results: Identifying key differences in patterns that distinguish between normal movement from those associated with osteoarthritis, and if changes in the shape the bones of the CMC joint or narrowing joint space can contribute to the disease.
Patient care application of results: Developing more effective diagnosis and intervention strategies for treating women with thumb carpal metacarpal (CMC) osteoarthritis.
Hoping for a Better Hand
OREF grant recipient is looking for better ways to diagnose and treat thumb carpal metacarpal osteoarthritis.
By Sally T. Halderman
Our opposable thumbs are among our defining human traits. But for too many of us, the extraordinary power and mobility of our thumb joints eventually exacts a high price—osteoarthritis.
Women are especially likely to pay that price. After women reach menopause, they develop osteoarthritis of the thumb carpal metacarpal (CMC) joint up to six times more often than do men. CMC osteoarthritis causes pain and swelling, and limits range of motion and the ability to apply opposable force. These symptoms undermine performance of everyday tasks such as grasping and lifting objects, opening jars, turning keys, and buttoning or zippering clothing.
“CMC osteoarthritis is an important issue in women’s musculoskeletal health,” said Amy L. Ladd, MD, Stanford professor of orthopaedic surgery and chief of the university’s Robert A. Chase Hand & Upper Limb Center. At least a quarter of women develop CMC osteoarthritis by age 55—a time in life when professional pursuits, household responsibilities and recreational activities still require great manual dexterity and strength of most women.
Better treatment tools
Given the high incidence and serious debilitation of CMC osteoarthritis, not enough is known about how or why it develops. Deeper anatomical and pathological insights are needed to support earlier detection, more efficient diagnosis and a wider range of interventions.
“We’re currently pretty good at pain relief—through surgery, if necessary—but we don’t yet know how to restore strength and dexterity. We can’t turn the functional clock back 20 years the way we can with a best-case total knee or hip replacement. We need better tools in our CMC treatment toolbox.”
Dr. Ladd aims to lay the groundwork for better tools with her project Thumb CMC Joint in Women: Anatomy and Function in Asymptomatic and Early Arthritic Subjects. Her work is supported by the 2010 RJOS/OREF/DePuy Career Development Grant in Women’s Musculoskeletal Health. OREF awards this grant in collaboration with the Ruth Jackson Orthopaedic Society (RJOS) and DePuy, Inc.
The goal of the RJOS/OREF/DePuy grant is to train and develop female orthopaedic surgeons to improve knowledge in women’s musculoskeletal health, and to enhance our understanding of gender and diversity differences in orthopaedic procedure outcomes. Female orthopaedic surgeons who are RJOS members are eligible to apply for the grant.
Understanding the Functional Dynamics of a Complex Joint
The thumb CMC joint performs a wide range of power and precision maneuvers. Yet there’s little scientific data documenting the detailed movement patterns in live subjects involved in these essential functions, how movement may differ in women and men with and without osteoarthritis, or whether differences in CMC joint load or joint spacing correlate with osteoarthritis severity.
Dr. Ladd’s RJOS/OREF/DePuy-funded project aims to begin building this evidence base as a first step toward developing more effective responses to CMC osteoarthritis. Her Stanford team is enrolling four young women with no symptoms of CMC osteoarthritis or history of thumb or wrist trauma, and four women with osteoarthritis to evaluate the complex motion of the hand and upper limb. Each will perform three tasks commonly affected by CMC osteoarthritis—turning a key, opening a jar and grasping an object. They will be studied in a motion lab, observing the compensatory movements of the upper limb with each task.
Further aspects of this study include anatomic and microscopic evaluation to better define the structural and stabilizing role of the thumb CMC ligaments.
NIH-Funded Study Will Expand Evidence Base
It’s a measure of the importance of Dr. Ladd’s project that her team recently received a grant from the National Institutes of Health (NIH) to explore related issues in a study enrolling more than 100 men and women. Joseph Crisco, PhD, one of Dr. Ladd’s Brown University collaborators in her RJOS/OREF/DePuy-funded work, is the principal investigator leading the NIH Research Project Grant Program (R01) investigation. This co-institutional collaboration will expand the preliminary study to evaluate both women and men performing these three tasks of turning a key, opening a jar, and grasping an object with markerless bone registration (MBR). MBR is a noninvasive technique that uses sequential computed tomography (CT) volumetric imaging studies and advanced analytic algorithms to provide high-resolution, three-dimensional data about movement patterns and anatomical structures.
In addition to identifying key differences in patterns that may distinguish normal movements from those associated with osteoarthritis, the study aims to determine whether characteristic changes in the shape of CMC joint bones or narrowing joint space (reduced distance separating bones) may correlate with osteoarthritis. Narrowing joint space has been shown in other joints to correlate with worsening degeneration. In fact, it’s currently the only validated outcome measure for progression of osteoarthritis in the knee.
Giving Back As a Way of Life
“The concept that you support the organizations that nurture you has pervaded my entire training,” said Dr. Ladd. “The philosophy of giving back begins with college, continues into medical training, and informs your professional life. If you’re grateful for your development opportunities, you want to help extend opportunities to others.
“OREF has been part of that environment of giving back throughout my career,” Dr. Ladd continued. “If you believe it’s important to connect clinical problems with research that can help solve them, you want to support the search for solutions.”
“I love clinical research. I’m thrilled that the RJOS/OREF/DePuy grant enables our team to adopt the broadest possible perspective, and explore how fundamental factors like biomechanics and anatomy may contribute to a clinical problem and point to better approaches to diagnosis and treatment.”
Dr. Ladd joined Stanford in 1990 as the first woman on the orthopaedics faculty. In addition to her role as a clinician and scientist, she also directs the university’s resident and medical student hand education programs and its hand fellowship. Her leadership has helped increase the proportion of female orthopaedics trainees at Stanford from one resident every few years to 25% to 40% of residents.