Reconstruction of the anterior cruciate ligament with a Patella-Tendon-Bone graft may lead to a permanent loss of bone mineral content due to decreased patellar tendon stiffness

If our hypothesis holds true, it may change patients' and surgeons' choice of management. Clinical follow-up should assess the functional result with greater scrutiny, possibly including the assessment of bone mineral content. This may be particularly important since there is accumulating evidence that a decrease in bone mineral density (BMD) preceedes, and hence may be a cause of, osteoarthritis.