Can tibial‑peroneal (common fibular) nerve injury below the knee on the left side cause plantar fasciitis?

Can Tibial-Peroneal Nerve Damage Below the Knee Cause Plantar Fasciitis?

No, tibial-peroneal (common fibular) nerve injury below the knee does not directly cause plantar fasciitis, but nerve entrapment of the tibial nerve and its branches can mimic or coexist with plantar fasciitis, creating diagnostic confusion.

Understanding the Relationship

Direct Causation is Not Established

• Plantar fasciitis is primarily a mechanical overuse condition affecting the plantar fascia attachment at the calcaneus, not a neurogenic disorder 1
• Common peroneal (fibular) nerve injury typically causes foot drop and affects ankle dorsiflexion/eversion, not plantar heel pain 2, 3
• The peroneal nerve does not innervate the plantar fascia or structures that would directly cause plantar fasciitis 2

Tibial Nerve Entrapment Can Mimic Plantar Fasciitis

• Injury to the tibial nerve and its branches in the tarsal tunnel is a common cause of plantar heel pain that can be confused with plantar fasciitis 4
• Entrapment of tibial nerve branches may play a role in both early phases of plantar heel pain and recalcitrant cases 4
• The posterior tibial nerve provides sensory innervation to the plantar heel, and its compression can produce symptoms similar to plantar fasciitis 5, 4

Diagnostic Approach for Plantar Heel Pain with Nerve Injury

Clinical Evaluation

• Peripheral neuropathy is the single most common component cause for foot ulceration in diabetic patients and should be assessed with 10-g monofilament testing plus one other neurologic assessment 6
• Look for specific signs distinguishing nerve entrapment from plantar fasciitis: radiation of pain, paresthesias, and positive Tinel's sign over the tarsal tunnel 4
• Assess for loss of protective sensation (LOPS) which indicates significant neuropathy 6

Imaging Strategy

• Weightbearing radiographs should be the initial imaging study for painful heel, with 85% sensitivity and 95% specificity for evaluating plantar fascia abnormalities 1
• If diagnosis remains unclear after 3 months of symptoms, obtain weightbearing radiographs to exclude other pathologies 1
• MRI is the most sensitive imaging study for definitive diagnosis when initial treatment fails 1
• Ultrasound shows 80% sensitivity and 88% specificity, with abnormal findings including plantar fascia thickness >4mm, focal echogenicity changes, and perifascial edema 1

Differential Diagnosis to Consider

• Tarsal tunnel syndrome (tibial nerve entrapment) should be considered as it can cause similar symptoms to plantar fasciitis 1, 4
• Calcaneal stress fracture can present with similar symptoms 1
• Plantar fascia rupture is a potential complication 1
• Denervation changes on MRI may show increased signal in foot muscles, joint effusions, and thickening of the posterior tibial nerve 6

Key Clinical Pitfalls

Common Diagnostic Errors

• Assuming all plantar heel pain in patients with neuropathy is plantar fasciitis without considering nerve entrapment 4
• The pathophysiology, diagnosis, and management of plantar heel pain of neural origin remain controversial despite being well-documented 4
• In diabetic patients with neuropathy, foot deformities and altered biomechanics may predispose to both nerve compression and plantar fasciitis simultaneously 6

Risk Factors for Foot Complications

• Poor glycemic management, peripheral neuropathy/LOPS, peripheral arterial disease, and foot deformities all increase risk for foot complications 6
• Annual comprehensive foot examination is required for all diabetic patients, with more frequent assessment for high-risk individuals 6
• Absent monofilament sensation plus one other abnormal neurologic test confirms LOPS 6