yogabook / pathology / baxter neuropathy – baxter nerve entrapment

Definition

Baxter’s neuropathy is a nerve compression syndrome of the inferior calcaneal nerve, which can lead to chronic nerve damage. It was first described in 1984 by Baxter using the example of
runners. It is estimated that up to 20% of all heel pain can be attributed to this. Possible causes include
plantar fasciitis, which is similarly localised with its pain. The bottleneck can be located between the abductor hallucis and the quadratus plantae or under the processus medialis calcanei at the base of the plantar fascia. If the nerve compression persists for a longer period of time, the nerve can be damaged to such an extent that the muscles it supplies atrophy. In the first case, this would be abductor hallucis and abductor digiti minimi, in the second case only the abductor digiti minimi. The tarsal tunnel syndrome and the nerve compression syndrome of the medial plantar nerve are similar in terms of differential diagnosis and also frequently occur in the context of running.

Cause

1. idiopathic nerve compression
2. Nerve compression due to changes in the neighbouring anatomical structures or the foot as a whole: plantar fasciitis, foot deformities especially with hyperpronation, hypermobility or instability of ankles
3. stress fractures
4. bony changes such as exostoses, osteophytes
5. accessory muscles
6. Joint damage, especially of the talocalcaneal subtalar joint
7. Arthritis of the subtalar joint

Predisposing

1. Medium and long distance running
2. Overweight
3. Foot deformities, in particular those with rearfoot valgus: knee bunion, lower foot, flat foot

Diagnosis

1. Medical history and clinic
2. MRI usually shows the cause of nerve compression and changes in the relevant muscles

Symptoms

1. plantar pain distal of the calcaneus as in plantar fasciitis, but also in the medial longitudinal arch
2. paresthesias in the region of the medial longitudinal arch, radiating towards the malleolus medialis
3. pain on exertion, start-up pain or pain that creeps in on exertion
4. pressure tenderness of the distal-plantar calcaneus. Palpation may trigger paraesthesia.
5. Possible reduction in strength of the abduction of the digitus minimus or the hallux

Complications

Therapy

1. Therapy of the causes
2. NSAIDs if necessary
3. Physiotherapy
4. Insoles
5. Softer, thicker shoe soles, also for running
6. Decompression neurolysis if necessary. According to Baxter 1992 with a very good success rate
7. Stress reduction or moderation

DD

1. Plantar fasciitis: this has no paraesthesia. However, it is often also present as a comorbidity or as a cause
2. Nerve compression syndrome of the medial plantar nerve: there plantar pain radiates towards the medial longitudinal arch of the foot up to the MTP