Ulnar nerve injury associated with removal of Norplant implants.

ABSTRACT

PIP: Due to the placement of the Norplant contraceptive implant system with respect to the neurovascular bundle of the arm, ulnar nerve injury is a possible complication of implant removal. Presented in this article is a case of ulnar nerve injury with subsequent neuropathy related to removal of improperly placed implants. The patient, a 23-year-old US woman, requested Norplant removal after 3.5 years of complication-free use. Before removal, the implants were noted to lie directly over the most anterior aspect of the triceps muscle, with the lower end of the implants lying about 5 cm from the medial condyle of the elbow. The patient returned to the facility 4 days after uneventful Norplant removal with persistent pain, definite weakness of the ulnar innervated muscles of the right hand, and numbness over the hypothenar eminence and fourth and fifth digits. Clinical neurologic evaluation was consistent with an ulnar nerve injury with diminished motor and sensory amplitude. Repeat studies at 6 weeks demonstrated improved motor response. Potential insertion-related injuries can best be prevented by choosing the appropriate placement site on the medial surface of the arm and by exaggerated tenting of the skin to help assure superficial subdermal placement and avoid deep structures. Before removal, identification of the path of the ulnar nerve and the relationship of the implants to the brachial groove is recommended, especially in thinner women. If pain, paresthesia, or anesthesia persists 4-6 weeks after an injury, repeat nerve conduction studies should be ordered to help outline a rehabilitation plan.