Rupture of the Extensor Digitorum Tendon of the Fifth Toe Caused by the Use of Press-Tack Needle Acupuncture During Sports Activity: A Case Report.

A 30-year-old female patient applied press-tack needles near the left fifth metatarsophalangeal joint to alleviate pain during table tennis. One month later, she presented with impaired dorsiflexion of the left fifth toe. Examination revealed a rupture of the left extensor digitorum longus tendon. Computed tomography was employed to confirm the rupture and associated scar tissue near the fifth metatarsal. Surgical repair revealed synovial hyperplasia, adhesions, and partial tendon degeneration, allowing successful end-to-end repair. Postoperatively, cast immobilization was implemented for four weeks, with a return to table tennis activities one year later. At one year, the patient achieved normal extensor muscle strength and satisfactory toe dorsiflexion and plantarflexion. To our knowledge, this represents the first reported case of extensor tendon rupture associated with press-tack needle use. Press-tack needles are widely available and often used casually without adequate medical expertise. The needle's placement over the extensor digitorum longus tendon likely led to synovitis, adhesions, and eventual tendon rupture. While press-tack needles are generally associated with minor complications, this case demonstrates that serious adverse events can occur when they are used improperly. This case emphasizes the importance of appropriate acupuncture training and cautious application, particularly near sensitive anatomical structures such as tendons, to prevent such complications.