Plantar interdigital neuroma or Morton's toe.

T HIS is to represent a not too uncommon condition of the foot which is painfuI and at times disabhng to the patient; a condition that can usuahy be reheved by surgery. It is known as pIantar interdigita1 neuroma or Morton’s toe. Thomas Morton originaIIy described this condition in 1876 at which time he suggested that it was an afhiction of the fourth metatarsophaIangea1 joint or a pinching of the digita branch of the IateraI pIantar nerve by the head of the fifth on the neck of the fourth metatarsa1 bone. Since that time the condition has been frequentIy described but it remained for Letts in 1940 to stimuIate its contemporary interest. He advanced a more sound etioIogic theory which was a stretching and irritation of the fourth digita nerve. This nerve differs anatomicaIIy from the other pIantar nerves in that it has a doubIe origin-a branch from the media1 as we11 as the IateraI pIantar nerve. In a review of the Iiterature it was noted that Thomas Morton described a surgica1 procedure for the aheviation of this condition, the excision of the fourth metatarsophaIangea1 joint. His description of the procedure is interesting for he emphasized the necessity to “excise a11 adjacent soft parts to insure excision of a11 surrounding nerve branches.” These Iast two words, “nerve branches,” suggest the reason for his cures. MiIIs in 1888 and HoadIey in 1893 stated that the fourth digita nerve was the invoIved nerve, not the fifth as suggested by Morton. HoadIey was the frrst to suggest that the nerve be removed but made no report of nerve resection. HoadIey in his report aIso suggested that a tear in the transverse Iigament depressed the fourth metatarsa1 head and thus initiated the irritation to the digita nerve. The history of trauma arose frequentIy in the case reports of the oIder literature but has been discounted or overlooked by contemporary authors. This might bear farther investigation. Sir Robert Jones and A. H. TubIey in 1898 noted there was a neuritis of the digita nerve and mentioned its doubIe origin. Both are points of significance, as wiI1 be shown Iater, but their importance was not reaIized. These men condemned the resection of the digita nerve as a dangerous procedure. It can be seen that by the work of the aforementioned physicians a11 the essentia1 eIements of pIantar interdigita1 neuroma, or Morton’s toe, were known by 1898. This did not, however, detract from the work done and reported by Betts of AdeIaide in 1940, and by McEIvenny of this country in 1943 ; for it was these men, working independentIy of each other and who, by correIation of anatomy, physica and operative findings, gave us our present concept of this pathoIogic condition of the foot.