Spinal Osteoarthritis in Geriatric Primates: A Proposed Radiologic Scoring System
Osteoarthritis (OA) is a leading cause of disability and reduced quality of life in humans. Prevalence of lumbar spine OA in humans ranges 40–85%, with 80% of Americans experiencing lumbar pain during their lifetime.1 A similar trend of high prevalence and associated pain is likely paralleled in nonhuman primates under human care.
This study proposes a standardized quantitative index for objective radiologic assessment of osteoarthritic changes of the spine. Ideal joint positioning for different imaging modalities is defined. Four key radiologic parameters are selected for evaluation of the spine: intervertebral disc space narrowing, vertebral endplate sclerosis, osteophyte formation, and articular facet changes.2 Focus is placed on spinal structures with adequate nerve supply, capable of generating pain. Each intervertebral space (IVS) in cervical, thoracic, and lumbar spine is scored for each of these four parameters on a five-point scale. Total score for each IVS is used to classify the joint as having absent, mild, moderate, severe, or profound osteoarthritis. Scores for each IVS can be summed for a regional OA score.
A standardized OA grading system will facilitate thorough evaluation and documentation of joint changes over time. Scores for spinal OA can be combined with OA scores for shoulders, elbows, hips, and knees to give an overall assessment of degenerative changes that may cause pain and impact mobility. With heightened awareness of indicators of early OA, targeted medical, behavioral, environmental, and physical interventions may improve animal comfort and welfare and ideally slow the progression of this debilitating disorder.
The authors thank Dr. Megan Freeman and Dr. Melissa King-Smith for their development of osteoarthritis scoring systems for the shoulders/elbows and hips/knees, respectively.
1. Goode AP, Carey TS, Jordan JM. Low back pain and lumbar spine osteoarthritis: how are they related? Curr Rheumatol Rep. 2013;15(2):305.
2. Kettler A, Wilke HJ. Review of existing grading systems for cervical or lumbar disc and facet joint degeneration. Eur Spine J. 2006;15(6):705–718.