Faulty Needle-Tips: Are They a Clinical Hazard?

Abstract

To the naked eye stainless steel, disposable acupuncture needles all look much the same, differing only in type of handle. But microscopically Xie and colleagues have shown some apparently shocking variations in needle-tip quality.1 A similar electron microscopic investigation 12 years ago found the same variety of faults: scratch marks, metallic scuff, lumps and irregularities of the needle surface, and stubbed, malformed or off-centre needle points (figure 1).2 Figure 1 Stubbed and malformed needle tips (×612.5). From Hayhoe et al .2 The first presterilised, single-use acupuncture needles were produced by the late Man Fong ‘Benny’ Mei, a coauthor of the original investigation. He was proud of his needles and believed them to be of excellent quality, so when he saw photomicrographs showing that his needles had tips as misshapen as those of most other types he went immediately to his factory in China to reassess quality control methods. Other distributors and manufacturers were equally surprised at the appearance of their own needles. The difficulty, of course, is the level of magnification necessary to see these needle-tip faults. Examined by the normal, naked eye, they are invisible. Xie's study used ×5000 magnification, although the earlier review had investigated a range of magnifications. With an ‘eye of faith’ the larger lumps and malformations could just be identified at lower powers, but for …