Endoscopic Plantar Fasciotomy

Plantar fasciitis is the most common cause of heel pain in adults.

The predominant symptom is pain in the plantar region of the foot when initiating walking.

The cause is a degenerative tear of part of the fascial origin from the calcaneus, followed by a tendinopathy-type reaction.

ANATOMY

The plantar fascia is a ligament with longitudinal fibers originating from the calcaneal tuberosity.

The normal medial band is the thickest, measuring up to 3 mm.

The central and lateral bands are 1 to 2 mm thick.¹

Distally, the plantar fascia divides into five slips, one for each toe.

The plantar fascia provides support to the arch. As the toes extend during the stance phase of gait, the plantar fascia is tightened by a windlass mechanism, resulting in elevation of the longitudinal arch, inversion of the hindfoot, and external rotation of the leg.

Endoscopically, the pertinent anatomy is the abductor hallucis muscle medially, then the plantar fascia. After fasciotomy, the flexor digitorum brevis comes into view as the medial intermuscular septum.

PATHOGENESIS

Specimens of plantar fascia obtained during surgery reveal a spectrum of changes, ranging from degeneration of fibrous tissue to fibroblastic proliferation.

The fascia is usually markedly thickened and gritty. These pathologic changes are more consistent with fasciosis (degenerative process) than fasciitis (inflammatory process), but fasciitis remains the accepted description in the literature.

NATURAL HISTORY

The typical patient is an adult who complains of plantar heel pain aggravated by activity and relieved by rest.

Start-up pain when initiating walking is common.

Strain of the plantar fascia can result from prolonged standing, running, or jumping and activities that create repetitive stress on the plantar fascia. Excessive pronation is a common mechanical cause.

The rigid cavus foot type can also predispose to plantar fasciitis.

Obesity is present in up to 70% of patients.

Plantar fasciitis is common among runners and ballet dancers.

About 15% of cases are bilateral. Women are affected more than men.

PHYSICAL FINDINGS

Localized tenderness over the plantar calcaneal tuberosity is the most common physical finding.

Pain is usually medial, but occasionally lateral. Rarely, pain may be located distally; this condition is called distal plantar fasciitis. Frequently there is soft tissue swelling of the plantar medial heel.

Careful comparison to the contralateral heel is useful in confirming tenderness typical for plantar fasciitis.

IMAGING AND OTHER DIAGNOSTIC STUDIES

Radiographs are ordered routinely in patients with plantar heel pain.

Plantar calcaneal spurs occur in up to 50% of patients but are not thought to cause heel pain; these are commonly associated with calcification in the origin of the flexor hallucis brevis, which is located proximal to the origin of the plantar fascia.

Stress fractures, unicameral bone cysts, and giant cell tumors are usually identified with plain radiography.

Three-phase technetium bone scans are rarely necessary but are positive in up to 95% of cases of plantar fasciitis.

MRI can be used in questionable cases and elegantly demonstrates thickening of the plantar fascia and rules out soft tissue and bone tumors, subtalar arthritis, and stress fractures.

Ultrasound is cost-effective and easily measures the thickness of the plantar fascia, documenting plantar fasciitis when thickness exceeds 3 mm.

DIFFERENTIAL DIAGNOSIS

Plantar fascia rupture: Generally occurs acutely after vigorous physical activity. There may be visible ecchymosis in the arch. MRI or ultrasound confirms the diagnosis.

Tarsal tunnel syndrome: Compression of the tibial nerve can cause numbness and pain in the heel, sole, or toes. Positive percussion and compression tests are elicited, and electromyography and nerve conduction studies are positive in 50% of cases.

Distal tarsal tunnel syndrome, compression of the first branch of the lateral plantar nerve (Baxter’s nerve), is often confused with plantar fasciitis and may be associated with plantar fasciitis. In fact, some surgeons recommend decompressing Baxter’s nerve with every plantar fascia release. In our opinion, these two entities are separate, and with careful examination plantar fasciitis may be isolated and effectively treated with endoscopic plantar fascia release.

Stress fractures: With a calcaneal stress fracture, tenderness is not localized to the plantar medial heel but instead is more diffusely present in the calcaneus, suggested by a calcaneal squeeze test. Plain films usually suggest a fracture line, but if there is any doubt, MRI clearly demonstrates stress fractures and readily distinguishes plantar fasciitis from stress fracture.

Neoplasms: Visualized on plain films at times. MRI is diagnostic. Pain is typically achy, constant, nocturnal, and even present without weight bearing and at rest.

Infection: Pain is often constant. There may be swelling, redness, or fluctuance. Plain films, MRI, or a white blood cell-labeled scan can be diagnostic. Laboratory tests may show increased erythrocyte sedimentation rate, C-reactive protein, or white blood cells.

Painful heel pad syndrome: Occurs most often in runners; thought to result from disruption of fibrous septa of the heel pad

Heel pad atrophy: Occurs in the elderly, usually not characterized by morning pain, and a “central heel pain syndrome” with tenderness more plantar than in plantar fasciitis, directly under the bony prominence in the calcaneus

Inflammatory arthritis: Usually bilateral and diffuse in nature. May be associated with positive RA, HLA, and B27 and an increased erythrocyte sedimentation rate.

NONOPERATIVE MANAGEMENT

Conservative management includes rest, ice, nonsteroidal anti-inflammatories, plantar fascia and Achilles tendon stretching, plantar fascia-specific stretching protocols, silicone heel pads, prefabricated and custom orthoses, night splints, CAM walkers, casts, physical therapy, athletic shoes, judicious use of steroid injections, and shockwave therapy.