Degenerated lumbricals in the feet of adult human cadavers: case series

In the foot, the lumbricals flex the metatarsophalangeal joints and extend the interphalangeal joints. The lumbricals are known to be affected in neuropathies. It is not known whether they may degenerate in normal individuals. Here, we report our findings of isolated degenerated lumbricals in seemingly normal feet of two cadavers. We explored lumbricals in 20 male and 8 female cadavers that were 60–80 years of age at the time of death. As part of routine dissection, we exposed the tendons of the flexor digitorum longus and the lumbricals. From the degenerated lumbricals, we took some tissue for paraffin-embedding, sectioning, and staining by hematoxylin and eosin, and Masson’s trichrome technique. Of the 224 lumbricals studied, we found four apparently degenerated lumbricals in two male cadavers. In the first, the 2nd and 4th lumbricals in the left foot and the 2nd in the right foot were degenerated. In the second, the right 4th lumbrical was degenerated. Microscopically, the degenerated tissue was made of bundles of collagen. The lumbricals may have degenerated due to compression of their nerve supply. We cannot comment on whether the functionality of the feet were affected by these isolated degeneration of the lumbricals.