Background: Morton’s neuroma is the enlargement of an interdigital nerve most commonly located between the third and fourth metatarsals. Greek foot is a normal variant where the first metatarsal is shorter than the second metatarsal. To our knowledge, there is currently no reported association between Greek foot and Morton’s neuroma in the literature. Methods: Retrospective study of 184 patients. Two separate cohorts were recruited. Cohort A comprised of 100 randomly selected asymptomatic patients. Cohort B comprised of 84 patients with a history of foot pain and histologically confirmed Morton’s neuroma. Foot shape was determined by using a self-assessment tool and plain radiographs. Statistical analyses were performed using the Chi-square test on the association between Greek foot and Morton’s neuroma. A p-value of <0.05 was considered statistically significant. Results: Our study shows a statistically significant association between Greek foot and Morton’s neuroma with a prevalence of Greek foot in Cohort A of 20% and in Cohort B of 63%. (p = 2.6 × 10<sup>﹣9</sup>). Conclusions: This study has shown a possible association between the presence of a Greek foot and the presence of Morton’s neuroma. Although our study design has limitations and does not allow full statistical analysis, we do believe that the shown association between Greek foot and Morton’s neuroma can help clinicians and other health care providers in establishing the diagnosis of Morton’s neuroma in patients with a painful foot.
Morton’s neuroma was first recognised by Lewis Durlacher in 1845, who described it as “a neuralgic affection” [
Although the name suggests that this condition is not considered to be a true neuroma as there is no tumour formation. Instead it is thought to be an entrapment neuropathy causing perineural fibrosis, nerve degeneration, leukocyte infiltration and epineural and endoneural vascular hyalinization, resulting in a thicker nerve that is even more susceptible to entrapment [
The aetiology of Morton’s neuroma is yet to be fully understood, although a few hypotheses exist. These include inflammation of the interdigital nerve [
Morton’s neuroma most commonly affects the third interdigital nerve but may also include the second, first and fourth nerves [
Morton’s neuroma usually presents with pain or a tingling or burning sensation at the distal end of the adjacent metatarsal heads radiating to the affected toes and the sensation of walking with a stone under the forefoot. The pain can usually be relieved by the removal of shoes, rest and manipulation of the foot [
On examination a positive Mulder’s sign is elicited, which is the production of a palpable, painful clicking sound when the interspace is palpated whilst the metatarsal heads are compressed laterally, causing the neuroma to be subluxed beneath the transverse metatarsal ligament [
Diagnosis is usually confirmed by the use of Radiographs, Ultrasound or Magnetic Resonance Imaging (MRI). However, it has been reported that physical examination and the production of Mulder’s sign is still the most sensitive and specific method of diagnosing Morton’s Neuroma [
Compression test of a Morton’s neuroma from the plantar (A) and dorsal (B) aspects
performed, which is curative in 80% of patients [
If not treated Morton’s neuroma can continue to enlarge causing increasingly severe foot pain that can be disabling. Chronically the pain can cause a compensatory change in gait in an attempt to relieve the pain, which can cause further problems in the back, hip, knee and ankle [
The procedure for removing an interdigital neuroma has changed multiple times since the first successful excision from the third web space was performed by A.E. Hoadley in 1883 [
Commonly the combination of nerve excision and ligament division is used. In the past isolated nerve excision was chosen due to concerns that division of the ligament would result in the foot being splayed post-opera- tively, this has since been disproven [
It is now thought that simple nerve excision (primary digital neurectomy) without ligament division leads to an increase in postoperative side effects, including recurrence of pain as without division of the ligament a symptomatic stump neuroma is formed [
Generally it has been agreed that primary surgery should be performed through the dorsal aspect of the foot as it allows earlier weight bearing and a quicker recovery [
Greek Foot is a normal variant in which there is a congenital shortening of the first metatarsal in relation to the second metatarsal bone (
There is no evidence in the current literature of a correlation between Greek foot and Morton’s neuroma. However, Dudley Morton [
The aim of this study was to investigate if Greek foot predisposes to Morton’s neuroma. This would be an important finding as it would not only aid with the diagnosis of Morton’s neuroma but also enable the detection of people who are at risk of developing the condition and allow primary preventative measures to be taken such
Photographs of a Greek (A) and Egyptian foot (B)
as the avoidance of high-heels. Such early intervention could result in fewer patients requiring surgery for Morton’s neuroma, therefore subjecting fewer patients to the potential complications of neurectomy, which include infection, wound dehiscence, haematoma, persistent or recurrent pain, swelling, numbness, anaesthesia-related and stump neuroma [
Retrospective study of 217 patients from a Caucasian population. Sample size was determined by the time limitations of the study. Eligible participants included people of 18 years of age or older.
Cohort A was a control group consisting of 133 randomly selected participants. 33 patients were excluded from the study due to the presence of foot pain.
Foot variant was determined by using a self-assessment tool.
Cohort B consisted of 84 patients who had undergone surgical excision of histologically confirmed Morton’s neuroma between 2003 and 2011.
Assessment of foot variant was performed by reviewing weight-bearing plain radiographs. Participants were deemed to have a Greek foot if the first metatarsal bone was shorter than the second metatarsal and an Egyptian foot if the first metatarsal bone was longer than the second.
Statistical analysis in the form of a Chi-squared test was performed to assess association between Greek foot and Morton’s Neuroma. A p-value of <0.05 was considered statistically significant.
Cohort A included 133 participants. 33 were excluded due to experiencing foot pain.
Mean age was 55.5 years (range 19 - 88). Cohort A consisted of 62 females and 38 males with a female-to- male ratio of 1.6:1.
80 (80%) participants had Egyptian foot variant and 20 (20%) demonstrated Greek foot (
Mean age was 54.3 years (range 19 - 87).
There were 70 females and 14 males, resulting in a female to male ratio of 5:1.
53 (63%) participants were found to have Greek foot and 31 (37%) had Egyptian foot (
A Chi-squared test was used to measure the association between Greek foot and Morton’s neuroma. The calculation produced a result of 35.4 (p = 2.6 × 10−9).
In 1927 the worldwide prevalence of Greek foot was estimated to be around 10% by Dudley Morton [
Although this result is significant we are unable to conclusively prove association due to limitations in study design preventing full statistical analysis, therefore necessitating further studies. One such limitation was due to the sample population used in Cohort B being taken from a population already diagnosed with Morton’s neuroma
Bar charts to show the relative number of participants with Egyptian and Greek foot types in Cohort A (asymptomatic population) and Cohort B (Morton’s neuroma patients)
resulting in selection bias. Furthermore the assessment of Greek foot in both cohorts was made using different techniques. Although these limitations exist the study has shown a possible association between Greek foot and Morton’s neuroma.
This association could be explained by the differences in weight bearing between individuals with Greek and Egyptian Foot variants. In an Egyptian foot the functional axis lies between the first and second metatarsal bones, therefore during walking, the body weight passes mostly over the larger first metatarsal. However in a Greek foot the presence of a longer second metatarsal bone causes the functional axis of the foot to move laterally to that of the longitudinal axis of the second metatarsal bone [
This association is an important finding as the presence of Greek foot could help clinicians establish the diagnosis of Morton’s neuroma in patients presenting with a painful foot. It could also allow advice and preventative measures to be given to patients with Greek foot to help prevent the development of Morton’s neuroma and any subsequent pain and disability.
This study shows the prevalence of Greek foot in individuals with no foot pain to be 20% (95% C.I.: 12% to 28%) and the prevalence of Greek foot in patients with Morton’s neuroma to be 63% (95% C.I.: 53% to 73%). This demonstrates a possible association between Greek foot and Morton’s neuroma. It also shows that the prevalence of Greek foot is higher in patients with Morton’s neuroma than in the asymptomatic population. Although a statistically significant association between Greek foot and Morton’s neuroma (p = 2.6 × 10−9) can be shown, a limited study design prevents full statistical analysis. However, we believe that the results are promising and that identification of Greek foot can help clinicians to establish a diagnosis of Morton’s neuroma.
We would like to thank Dr. Stephen Raftery of St. Helens and Knowsley NHS Trust for helping with the statistical analysis in this study.