People who have had knee surgery following trauma may be susceptible to osteoarthritis sooner than currently thought, an Australian led MRI study reports.

Almost a third of people studied had some evidence of early osteoarthritis (OA) at one year, challenging “existing dogma that degenerative joint disease does not become apparent for years post-ACLR,” reported Dr. Kay Crossley of the University of Queensland in Brisbane.

However as they did not have access to preoperative images, they could not rule out that some OA features may have been preexisting and not related to knee trauma.

Their study included 111 patients aged 18-50 years who had undergone single-bundle hamstring-tendon autograft ACLR 1 year earlier.

Results showed that 34 (31%) patients had MRI-defined (using MOAKS) knee OA following an ACLR a year earlier.

MRI-OA features were most frequently found in the patellofemoral compartment, particularly the medial femoral trochlea, a potentially underrecognized site of knee pathology following reconstruction, the researchers said.

No evidence of OA was seen in the 2o  uninjured asymptomatic matched controls, found the study published in Arthritis and Rheumatology.