Botulinum toxin type A in the treatment of painful adductor muscle contracture after total hip arthroplasty.

Painful adductor muscle contracture is an important cause of failure during rehabilitation following total hip arthroplasty (THA). Adductor muscle contracture may be caused by postoperative muscle retractions, adhesive capsulitis, postoperative leg-length inequalities caused by implant failure, or preexisting hip pathologies. A 34-year-old woman experienced a persistent painful contracture into the left adductor magnus muscle after THA. She had no leg-length inequalities and, according to the Medical Research Council scale (grades 0-5), muscle strength of the quadriceps was 5/5 for the right side and 3/5 for the left. The degree of functionality according to the Harris hip score (HHS) was 16/100 in the left hip. The pain level, measured with the visual analog scale (VAS), was 7/10. The patient was unable to fully adhere to the rehabilitation program and walked with a limp during the stance phase of gait. After 7 days of treatment with injections of botulinum toxin type A into the left adductor magnus muscle (dose, 150 UM) and subsequent rehabilitation, a great reduction of painful contracture was observed (VAS score, 2/10). The procedure was well tolerated and no adverse effects were noted. After 20 days, hip articular range of motion and gait had improved (HHS score, 75/100). The clinical effects of botulinum toxin type A were present at 2-month follow-up. This treatment may be a viable alternative for the management of painful adductor muscle contracture after THA, without significant side effects.