Loss of bone mineral of the hip and proximal tibia following rupture of the Achilles tendon

In a prospective uncontrolled study 12 patients suffering from a rupture of the Achilles tendon treated operatively with surgical repair and post‐operative immobilization in a short plaster cast for 6 weeks had bilateral measurements of bone mineral content (BMC) of the proximal tibia and bone mineral density (BMD) of the femoral neck and greater trochanter. The measurements were performed by dual energy X‐ray absorptiometry (DEXA) and scans were performed post‐operatively within 7 days after the operation and with follow up after 6 weeks, 3, 6, and 12 months. In the operated legs, BMC of the proximal tibia showed a progressive decrease reaching a total bone loss of 6.4% (95%‐CL: −10.6%; −2.3%) 1 year after the injury. Bone mineral density at the hip of the operated legs also decreased significantly and 1 year after the injury BMD was 2.5% (95%‐CL: −5.5%; 0.5%) and 6.8% (95%‐CL: −9.8%; −3.7%) below the initial value in, respectively, the femoral neck and greater trochanter. Patients with a previous Achilles tendon rupture must be considered to be some years ahead in their natural osteoporotic process of the bones of the affected legs, and an increased risk of osteoporotic fractures must be considered not to be only theoretical.