Morton's Neuroma / Metatarsalgia Secondary to Pes Planus (Flat Feet)

Yes. Under 38 CFR § 3.310(a), any disability proximately caused or chronically worsened by a service-connected condition is itself service-connected. Morton's Neuroma / Metatarsalgia is a documented secondary pairing for Pes Planus (Flat Feet) with moderate medical evidence. A nexus letter from a qualified physician linking the two conditions is the most reliable way to establish this connection.

The gold standard is a private nexus opinion stating — to at least a 50% probability ("at least as likely as not") — that the secondary condition was caused or aggravated by the primary service-connected condition. Peer-reviewed medical literature supporting the physiological mechanism strengthens the nexus. Treatment records documenting the onset or worsening of the secondary condition in temporal relation to the primary are supporting evidence.

The VA rates Morton's Neuroma / Metatarsalgia separately under its own 38 CFR Part 4 diagnostic code, then combines it with Pes Planus (Flat Feet) and all other service-connected ratings using the combined ratings formula under § 4.25. The formula applies the whole-person concept: a 50% combined existing rating plus a new 30% rating yields 65% (rounded to 70%), not 80%.

38 CFR § 3.310(a) states: "Disability which is proximately due to or the result of a service-connected disease or injury shall be service connected." The aggravation variant under § 3.310(b) applies where the primary condition permanently worsens a pre-existing disability beyond its natural progression. Both standards require a showing of nexus — a medical or scientific link between the primary condition and the secondary.

The medical evidence supporting Morton's Neuroma / Metatarsalgia as secondary to Pes Planus (Flat Feet) is rated moderate. Pes planus creates excessive forefoot loading and abnormal metatarsal head pressure distribution during the push-off phase of gait. The pronated foot position causes hypermobility of the first ray and transfers weight laterally to the second and third metatarsal heads, compressing the interdigital nerves (particularly the third common digital nerve between the 3rd and 4th metatarsal heads). This chronic compression and traction on the nerve produces perineural fibrosis — Morton's neuroma. The collapsed medial arch also increases transverse metatarsal arch loading, further narrowing the intermetatarsal spaces. Pedobarographic studies show 40-60% higher peak pressures under the 2nd and 3rd metatarsal heads in pes planus compared to normal arches.

The VA will not solicit nexus evidence on your behalf for secondary claims. In practice, a written nexus opinion from a private physician or independent medical examiner is essential — the VA's Compensation & Pension (C&P) examiner is not required to produce a favorable nexus opinion, and the VA has discretion to weigh competing opinions. Submitting a private nexus letter at the time of filing is the most reliable strategy.