WHAT IS INVOLVED

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Posterior Tibial Nerve


LOCATION

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Posterior Tibial nerve entrapment at the Tarsal Tunnel in the foot at the level of the medial malleolus


COMMON SYMPTOMS

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- Foot, Ankle, Sole pain/burning and aching

- Worse at night

- Occasional numbness/tingling sole of foot

- No muscle weakness

- Usually unilateral

- Difficulty walking because of pain and discomfort with shoes

- Positive Tinel (tingling upon tapping nerve) sign behind the medial malleolus


ONSET

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- May be Sudden in trauma, injury

- Usually Gradual, weeks, months


RISK FACTORS

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- No gender preference

- Diabetes or family history of Diabetes, Alcoholism or other occupational or nutritional causes of Neuropathies, HIV infection

- Usually post-traumatic

- Can be aggravated with joint inflammation from tenosynovitis, phlebitis


EXAM

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- Very positive and tender Tinel (tingling upon tapping nerve) sign behind the medial malleolus

- Usually ankle swelling, tenderness

- No weakness or atrophy

- May have decreased sensation over the sole of the foot

- Patient quite uncomfortable with standing, walking


LOCALIZATION

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The Posterior Tibial nerve inside the Tarsal Tunnel affecting both Medial and Lateral Plantar nerves of the foot


EMG

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- Prolonged Posterior Tibial distal latency to the Abductor Hallucis or Abductor Digiti Quinti Pedis

- May be accompanied by low motor amplitude or absent responses in either of these muscles

- Medial and/or Lateral plantar sensory action potentials may be affected early on with prolonged latency, slowed velocity and decreased amplitude

- Sensory Action potentials unobtainable in advanced cases

- Needle exam of Abductor Hallucis and/or Abductor Digiti Quinti Pedis may show denervation, active and/or chronic

- Check non-Posterior Tibial muscles (Extensor Digitorum Brevis) or Posterior Tibial muscles above the Tarsal Tunnel (Posterior Tibialis) are spared and Lumbo-Sacral paraspinals are intact to ensure this is not an S1 root lesion


RECOMMENDATIONS

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- Symptomatic treatment by relieving cause and treating local trauma

- Foot brace and arch support

- Anti inflammatory medications

- Surgery in advanced cases

- In complicated and post-operative ankle injuries, surgery may actually worsen the symptoms


WHAT ELSE COULD IT BE?

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- Could be ankle joint pain without involvement of the Posterior Tibial nerve

- If bilateral, suspect Diabetes, Small Fiber Neuropathy (symptoms not just limited to the foot), but more importantly, bilateral S1 root lesions