An accidental break of an acupuncture needle is one of the most serious complication in acupuncture.
A German Shepherd weighed 25kg was anesthetized with pentobarbital.
Then, unused 7 needles of 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0cm long each were inserted at 7 acupuncture points.
The movement of broken acupuncture needles were observed by X-ray for 72 days and pathological examination of tissue surrounding broken needles was also done.
While broken needles inserted nearby the joints were found moving much around, others inserted in the region of straight bones stayed almost.
The dog was dissected 72 days after the preparation. Three broken needles were found just beneath the muscular fascia and two broken needles were in the subcutaneous tissue. Another broken needle in the lumbar region was penetrated into the lumbar spinal cord and the other needle in the region of neck was lost.
Pathological examination showed chronic inflammatory changes such as cellular infiltration and muscle fiber necrosis in the lumbar spinal cord and the thigh region, but little changes in the other four regions.