Studies have shown that tendon insertion site injuries can lead to bone loss. Following tendon-bone repair, bone loss can lead to widening of the repair tunnel. This widening may negatively affect the establishment of a strong tendon-bone interface, leading to recurrence of failure. Our goal was to suppress bone loss after insertion site repair using alendronate in an attempt to prevent the decrease in biomechanical properties. Flexor digitorum profundus tendons were injured and repaired into bone tunnels In the distal phalanx in seven canines. Dogs received a daily oral dose of alendronate. Dogs also received a local dose of alendronate in the bone tunnels of either the second or fifth digit at the time of surgery. Insertions were evaluated at 21 days for mechanical properties and bone mineral density. Our data indicated that tendon to bone healing can be improved by preventing bone loss. We showed that: 1) alendronate prevents the bone loss which occurs after tendon to bone repair and 2) prevention of bone loss leads to significantly improved mechanical properties. This effect may be because there is a more stable surface for tendon-bone integration or because there is less inflammatory tendon degradation in the bone tunnel.