Could the patient's symptoms be due to a mechanical cause like Posterior Tibial Tendon Dysfunction (PTTD) or pivotal disc (pivd) issues?

Low Back Pain and Mechanical Causes: PTTD vs PIVD

Low back pain is most commonly due to mechanical causes like prolapsed intervertebral disc (PIVD), not Posterior Tibial Tendon Dysfunction (PTTD), which affects the foot and ankle—these are anatomically distinct conditions that do not cause each other's symptoms.

Anatomical Distinction

• PTTD is a foot and ankle pathology involving the posterior tibial tendon that runs along the medial ankle and inserts into the midfoot, causing medial ankle pain, foot deformity, and progressive flatfoot 1, 2
• PIVD (prolapsed intervertebral disc) is a spinal pathology causing low back pain through mechanical nerve root compression from degenerative disc disease 3
• These conditions affect completely different anatomical regions and cannot be confused as causative of each other 3, 1

Clinical Presentation of PTTD

PTTD presents with specific foot and ankle symptoms, not back pain:

• Medial ankle pain and swelling along the posterior tibial tendon course 4
• Progressive flatfoot deformity with loss of the medial longitudinal arch 1, 2
• Difficulty performing single-leg heel raises 4
• Pain worsens with weightbearing and walking 5, 4
• Weakness in inversion and plantarflexion strength on isokinetic testing 4

Clinical Presentation of PIVD

PIVD presents with back and lower extremity radicular symptoms:

• Thoracic or lumbar back pain as the primary complaint 3
• Radiculopathy with motor/sensory deficits (61% of symptomatic cases) 3
• Possible myelopathy with spasticity/hyperreflexia (58%) and positive Babinski sign (55%) 3
• Bladder dysfunction in severe cases (24%) 3
• Pain may radiate into lower extremities following dermatomal patterns, but this is neurogenic, not mechanical foot pathology 3

Diagnostic Approach for Low Back Pain

When evaluating low back pain, assess for "red flags" that indicate serious pathology requiring imaging:

• Trauma, malignancy, prior spine surgery, spinal cord injury 3
• Systemic diseases including ankylosing spondylitis, inflammatory arthritis 3
• Suspected infection, history of intravenous drug use 3
• Intractable pain despite therapy, tenderness over vertebral body 3
• Neurological deficits or myelopathy/radiculopathy 3

For back pain with myelopathy or radiculopathy, MRI of the thoracic or lumbar spine without IV contrast is the initial imaging modality of choice to identify compressive etiologies including disc herniations, spinal stenosis, or facet arthropathy 3

Diagnostic Approach for PTTD

PTTD diagnosis is clinical, based on foot and ankle examination:

• Palpable and painful posterior tibial tendon with or without swelling 4
• Observable tendon movement with passive and active non-weightbearing examination 4
• Plain radiography shows talo-MT1 angle abnormalities, decreased calcaneal pitch, and loss of medial arch 2
• Ultrasound may show circumferential fluid (19.2%), heterogenicity (11.7%), or tendon thickening (8.3%) even in early subclinical disease 5
• Reserve advanced imaging (MRI/ultrasound) for unclear diagnoses or recalcitrant pain despite conservative management 6

Treatment Implications

For PIVD with back pain:

• Conservative management initially unless red flags present 3
• MRI indicated for myelopathy, radiculopathy, or progressive neurological deficits 3
• Surgery indicated for severe intractable pain or progressive/severe myelopathy 3

For PTTD (Stage I or II):

• 83% success rate with structured nonoperative protocol including short articulated ankle-foot orthosis, eccentric strengthening exercises, and aggressive plantarflexion activities over 4 months 4
• Relative rest to decrease repetitive loading while avoiding complete immobilization 6, 7
• Surgical reconstruction with flexor digitorum longus substitution combined with calcaneal osteotomy reserved for failure after 3-6 months of conservative treatment 1, 2

Common Pitfall

Do not attribute low back pain to foot pathology or vice versa. These are separate mechanical problems requiring distinct diagnostic and therapeutic approaches. If a patient presents with both low back pain and foot/ankle symptoms, evaluate each region independently with appropriate history, examination, and imaging 3, 4.