Researchers and clinicians often point to biomechanical elements, particularly aberrant biomechanical forces and pathological responses to them, as key factors in osteoarthritis (OA) disease progression. However, little is known about which parameters are most important and what their effects are on the disease process. Recently published studies and review articles that have addressed various aspects of the relationships between biomechanics and knee OA include the following:
•"The measurement of joint mechanics and their role in osteoarthritis genesis and progression," a review authored by Wilson and colleagues in the department of orthopedics at the University of British Columbia in Vancouver, summarized the methods for assessing joint mechanics and their relative merits and limitations, the current evidence for the role of mechanics in OA initiation and progression, and current treatment approaches that focus on modifying the mechanics. The article appeared in January in Medical Clinics of North America.
•In "Alignment and osteoarthritis of the knee," Hunter and associates in the division of research, New England Baptist Hospital, Boston, discussed malalignment as a predictor of disease progression. They noted that malalignment mediates the effects of other risk factors, including obesity, quadriceps strength, laxity, and disease stage; appears to play a lesser role in increasing the risk of incident tibiofemoral OA; changes with disease progression; and may be influenced by structural changes within the knee joint. The article appeared in February in the Journal of Bone and Joint Surgery, American volume.
•In the same issue, Andriacchi and colleagues from the department of mechanical engineering at Stanford University examined the response of healthy and diseased cartilage of the knee to the mechanics of walking. They concluded that individual variations in the range of loading and kinematics at the knee during walking can have a profound influence on the initiation and progression of knee OA.
•Levinger and colleagues at the Musculoskeletal Research Centre, La Trobe University, Bundoora, Victoria, Australia, investigated the application of support vector machines to classify gait patterns indicative of knee OA before surgery based on 12 spatiotemporal gait parameters and whether the machines could be used to predict gait improvement after knee replacement surgery. Their results, reported in Gait & Posture in January, suggested that spatiotemporal parameters contain important discriminative information that may be used for identifying pathological gait.
•In "Linking biomechanics to mobility and disability in people with knee osteoarthritis," Maly at the School of Rehabilitation Science, McMaster University, Hamilton, Ontario, developed a novel OA construct, "careful mobility," by linking qualitative and quantitative methods to study both patient experience and biomechanics. His review appeared in Exercise and Sport Sciences Reviews in January.
•The influence of muscle activity on knee-joint loading was outlined by Bennell and colleagues at the Centre for Health, Exercise and Sports Medicine, School of Physiotherapy, University of Melbourne, Victoria, Australia, in the January Medical Clinics of North America. The authors described the deficits in muscle function observed in persons with knee OA, summarized available evidence about the role of muscle in the development and progression of knee OA, and concluded with a discussion of exercise prescription for muscle rehabilitation.
•In "The biomechanics of osteoarthritis: implications for therapy," by Block and Shakoor, section of rheumatology, Rush Medical College, Rush University Medical Center in Chicago, the authors reviewed novel therapeutic approaches that may provide prolonged reductions in loading of OA joints and, ultimately, be shown to retard disease progression and palliate pain. The article appeared in Current Rheumatology Reports in February.
•Gross and Hillstrom provided an introduction to the main noninvasive devices used in conservative management of symptomatic knee OA, noting that demand for noninvasive and nonpharmacological therapies for OA is enormous and that there is a pressing need for primary care physicians to respond by updating their pattern of practice. The authors are from the MGH Institute of Health Professions, Graduate Programs in Physical Therapy, Charlestown Navy Yard, Boston. The article, "Knee osteoarthritis: primary care using noninvasive devices and biomechanical principles," appeared in Medical Clinics of North America in January.