Collagen deficit may cause osteoarthritis

DURHAM, N.C., Aug. 31 (UPI) -- U.S. scientists studying mice have found a deficiency of a certain type of collagen causes osteoarthritis and degenerative disc disease.

The Duke University Medical Center researchers said they found mice with their Type IX collagen gene inactivated prematurely developed the common and chronic musculoskeletal disorders. Both diseases cause joint pain and loss of function.

The scientists, led by postdoctoral fellow Kyle Allen, compared behavioral abilities of collagen deficient mice to wild-type mice.

"We observed a pattern of behavioral changes in the collagen deficient mice that suggests a relationship to (osteoarthritis and degenerative disc disease)," said Allen, who noted the collagen deficient mice also had elevated levels of knee and intervertebral disc structural changes.

The scientists said collagen deficient mice chose movements that limited peak joint forces and behaviors that reduced pain sensations.

"In future work, these measures may help track signs and symptoms as degeneration progresses," Allen added. "Further studies of the mouse model could provide useful data for evaluating the efficacy of therapeutic interventions for musculoskeletal disorders."

The research is reported in the September issue of the journal Arthritis & Rheumatism.