Botulinum toxin as a solution in voluntary hip dislocation after modular unipolar hemiarthroplasty

This article presents a case of an 82-year-old woman with Alzheimer's disease who was treated with a modular unipolar hemiarthroplasty for a right femoral neck fracture, which she voluntarily dislocated 3 times in the first postoperative week. The hip was stable in all directions, even in 60 degrees internal rotation, 0 degrees abduction, and 90 degrees flexion. The patient was mobilized 1 day postoperatively with full weight bearing. She dislocated her hip on postoperative day 3 while lying on her bed. After the dislocation, reduction under sedation was done again followed by a botulinum toxin injection of 50 IU to her adductor muscle group (including adductor longus, brevis, and magnus). The patient was mobilized after the injection and she had no difficulty walking. During the 6 months after the injection, no dislocation occurred again. Botulinum toxin decreases muscle activity by blocking the release of acetylcholine at the neuromuscular junction, thereby rendering the muscle unable to contract for up to 3 to 4 months. This method of botulinum injection can be applied to noncompliant patients with mental problems as an alternative conservative and surgical approaches.