Endoscopic Plantar Fascia Release

Indications

Plantar fasciitis is the most common cause of plantar heel pain.¹ Non-surgical treatment is successful in mitigating the majority of patient complaints; 90% of patients can expect symptom resolution at an average of 8 to 10 months from onset. ^2,3 Although most patients will experience symptom relief with conservative management, a small subset remains recalcitrant to non-operative treatment, thus making them potential operative candidates.  Most authors believe surgical intervention should be considered only after patients fail to respond to a 12-month course of non-operative management.

Preoperative Planning

Various causes of heel pain should be considered prior to endoscopic plantar fasciotomy (EPFR). These include neoplasia, infection, calcaneal stress fracture, heel pad atrophy, systemic inflammatory disease, and nerve compression. Plain radiographs should be obtained to rule out stress fracture, neoplasia, and osteomyelitis. Investigation for systemic inflammatory disease with erythrocyte sedimentation rate, anti-nuclear body, HLA-B27, and rheumatoid factor should be considered if clinically warranted. All patients should undergo a careful neurologic examination and if indicated, an electromyography and nerve conduction velocity test should be obtained to evaluate for possible neuropathy or nerve entrapment. Positive radiographs, positive inflammatory panel, or positive EMG/NV are  a relative contraindication to endoscopic plantar fascial release.⁴ Moreover, in the setting of moderate to severe pes planus, EPFR should not be utilized due the risk of further destabilization of the longitudinal arch.²

Positioning

The patient is placed supine, with the operative heel hanging off the end of the surgical table (Figure 1).

Figure1. Foot positioning

Approach

Two portal technique with medial and lateral portal.

Techniques ^2,4

After administration of pre-operative antibiotics, either regional or general anesthesia is given.  The author's preferred method is intravenous sedation and local anesthesia, consisting of posterior tibial and sural nerve blockade.  The patient is prepped and draped in a standard aseptic manner.  The foot is exsanguinated and an ankle tourniquet applied.  The medial portal is located over a reference point that is immediately anterior and inferior to the inferior aspect of the medial calcaneal tubercle, as viewed on a non-weight bearing lateral projection.  Extending a line distally from the posterior aspect of the medial malleolus can approximate the frontal plane placement of the medial portal (Figure 2). This portal position evades injury to medial neurovascular structures.

Figure 2. Placement of medial portal

A vertical, 5-mm stab incision is performed, incising the skin only, then bluntly dissecting inferiorly to the level of the plantar fascia.  Care is taken to ensure the dissection is plantar to the fascia to avoid neurovascular injury.  This is accomplished by direct palpation, since visualization through this small incision is not possible.  Various endoscopic systems can be utilized to perform the release; however, the requisite components consist of a short, 30-degree, 4-mm arthroscope, fascial elevator, hook probe, slotted obturator/cannula system, disposable hook and triangle blades. Initially, the facial elevator is inserted into the medial portal and the medial investment of the plantar fascia is palpated. The fascial elevator is then employed to remove soft tissue from the plantar aspects of the fascia, thereby, creating a conduit immediately inferior to the plantar fascia.  

The obturator/cannula system is introduced medially into this tunnel, and advanced across the inferior surface of the plantar fascia to the lateral aspect of the foot (Figure 3).  The obturator is aligned parallel to the floor while the toes are pointing directly up. The tip of the obturator is then palpated laterally. A vertical, 5-mm incision is placed over the tip of the obturator, which allows the obturator/cannula to pass through the skin.  The obturator is removed from the slotted cannula, leaving the cannula in place with the slot directed superiorly toward the plantar fascia.  The endoscope is next introduced medially and the fascial probe laterally.  Using the endoscope, the entire inferior surface of the plantar fascia is viewed on the monitor.  If fat is blocking the view, multiple passes with a sterile cotton swabs improves visualization.

Figure 3. Medial edge of plantar fascia

The width of the plantar fascia is then determined and the probe is marked with the surgical marker at the medial and lateral edges of the planar fascia.  These measurements are transferred to the hook knife and the hook knife is inserted from lateral to medial (Figure 4).

Figure 4. Transfer of measurements to hook knife

The arthroscope is then placed just medial to the medial edge of the plantar fascia. The hook knife is placed in the lateral portal and used to sever the medial one third of the fascia (approximately 7-10 mm) with the ankle and toes dorsiflexed.  Care is taken to perform only a medial one-third release to minimize the amount of destabilization of the longitudinal arch.  As the fascia is severed, the muscle of the flexor digitorum brevis is visualized through the slotted cannula.  Usually two or three passes with the blade are required for a full-thickness partial release (Figure 5). A triangle knife is utilized in patients whose fascia is markedly thickened.

Figure 5. Plantar fascial release

The ankle and toes are again maximally dorsiflexed and separation of the edges of the plantar fascia is seen (Figure 6).

Figure 6. Separation of the edges of the plantar fascia with visualization of the flexor digitorum brevis

After release of the plantar fascia, some authors recommend releasing a portion of the deep fascia of the abductor hallucis to potentially relieve subtle pressure on the nerve.⁴  Once satisfied with the release, the cannula is removed and the plantar fascia is palpated for confirmation. The tourniquet is released and the operative site is irrigated. The wounds are closed with a 4.0 nylon mattress stitch.

Pearls and Pitfalls

Proper portal placement is requisite to minimize complications and the likelihood of injury to the local neurovascular structures.  Use of a medial portal in line with the posterior border of the medial malleolus provides for a safe zone, devoid of critical structures.  Several studies^2,5 have revealed the nerve to the abductor digiti minimal to be approximately 10 mm dorsal to the plantar fascia; thus, if the surgeon’s instruments are plantar to the fascia and the muscle belly of the flexor brevis is not resected, the nerve is safe.

Biomechanical analysis has established excessive plantar fascial release destabilizes the arch complex, which can lead to residual lateral plantar heel pain or overt arch collapse.⁶ Therefore, release only one third of the plantar fascia.

Postoperative Care

Patients are placed in a soft dressing and CAM walker and then allowed to weight bear as tolerate. 

Outcome

Bazaz et al⁴ published a retrospective study on 19 feet with an average follow up of 47 months.  The average AOFAS-hindfoot score improved from 66 to 88.  The author found patients with symptoms greater than 2 years prior to endoscopic plantar fascial release had decreased postoperative scores compared to patients with symptoms less than 2 years. Obesity did not significantly lower functional outcome scores, and workman compensation patients demonstrated inferior results compared to non-workman compensation patients.

O’Malley and Page² authored a consecutive study of a single surgeon using a two portal technique with a validated functional outcome measure.  The results of 20 feet followed for an average of 22 months were reported. The average AOFAS-hindfoot score improved from 62 to 80.  Overall, 85% were satisfied with the results of endoscopic plantar fascia release.  The authors noted an inferior result in patients undergoing bilateral release staged or simultaneous compared to unilateral release.  No intra-operative complications were reported; however, four feet had residual discomfort at the portal sites.

Barrett et al⁷ published the largest cohort of patients undergoing endoscopic plantar fasciotomy.  The study described the results of 652 cases performed by 25 different surgeons.  Pain reduction was documented in 97% of patients at 8 months using a 5-point scale.

Complications

Complications reported in the literature include:

• Portal tenderness
• Lateral heel pain
• Arch destabilization
• Portal infection
• Calcaneal stress fracture
• Complex regional pain syndrome
• Pseudo aneurysm of the lateral plantar artery.^{5, 8,9,10}

References

1. Tisdel, CL: Heel pain, in Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL: American Academy of Orthopaedic Surgeons, 2003, pp 113-119
2. O’Malley, M; Page, A; Cook, R:  Endoscopic plantar fasciotomy for chronic heel pain.  Foot Ankle Int 21:505-510, 2000
3. Wolgin, M., Cook, C., Graham, C., and Mauldin, D.: Conservative treatment of plantar heel pain:  Long term follow-up.  Foot Ankle Int. 15:97-102, 1994.
4. Bazaz, R; Ferkel, R:  Results of endoscopic plantar fascia release.  Foot and Ankle Int.  28:549-556, 2007.
5. Palumbo, RC; Kodros, SA; Baxter, DE: Endoscopic plantar fasciotomy: Indications, techniques, and complications. Sports Med. Arthroscopy Rev. 2:317-322, 1994.
6. Brugh, AM; Fallat, LM; et al.: Lateral column symptomatology following plantar fascial release: a prospective. J. Foot Ankle Surg. 41:365-371, 2002.
7. Barrett, SL; Day, SV: Endoscopic plantar fasciotomy: a multi surgeon prospective analysis of 652 cases. J. Foot Ankle Surg. 34:400-406, 1995.
8. Ogilvie-Harris, DJ; Lobo, J: Endoscopic plantar fascia release . Arthroscopy. 16:290-298, 2000.
9. Gentile, AT; Zizzo, CJ; Dehukey, A; Berman, SS: Traumatic pseudoaneurysm of the lateral plantar artery after endoscopic plantar fasciotomy. Foot Ankle Int. 18:821-822, 1997.
10. Boyle, RA; Slater, GL: Endoscopic Plantar Fascial Release: a case series. Foot Ankle Int. 24:176-179, 2003.