Revisional Tarsal Tunnel Surgery

Revisional Tarsal Tunnel Surgery

Edgardo Rodriguez-Collazo, Stephanie Oexeman, Peter J. Bregman


By definition, tarsal tunnel syndrome is extrinsic, intrinsic, or a combination compression of the tibial nerve that presents in the lower extremity tarsal tunnel. Within the literature, there are results ranging from 44% to 95% success rates after a primary neurolysis of the tibial nerve at the level of the tarsal tunnel.1 Success rates are even less promising for patients who undergo revisional procedures. After a failed tarsal tunnel procedure, it is crucial to determine why the primary surgery failed and subsequently treat the correct underlying cause. In this chapter, the authors discuss how to identify tibial nerve injuries, determine the correct etiology for tarsal tunnel syndrome, and evaluate clinically and discuss revisional tarsal tunnel and tibial nerve surgical procedures.

The Tibial Nerve and Injuries

The Tibial Nerve

The tibial nerve originates from the lumbar and sacral plexus and is a continuation from the sciatic nerve. It contains fibers from L4, L5, S1, S2, and S3, providing both motor and sensory function to the lower extremity. The nerve provides motor function to the posterior muscle group of the lower extremity and sensory function to the posterior, medial, and lateral plantar regions of the leg and foot. Anatomically, the tibial nerve crosses the popliteal fossa and travels between the medial and lateral heads of the gastrocnemius muscle. Moving distally, the tibial nerve crosses below the upper level of the fibrous arch of the soleus muscle. Descending toward the ankle, the tibial nerve travels beneath the flexor retinaculum and enters the tarsal tunnel at the level of the medial malleolus. The distal tibial nerve then divides into 4 terminal branches. The medial and lateral calcaneal nerves are purely sensory and supply sensation to the heel of the foot. The medial and lateral plantar nerves contain both motor and sensory fibers.2 The site of division is variable, particularly for the calcaneal nerve, and can occasionally occur proximally or distally to the tarsal tunnel. Studies have shown that the medial and lateral plantar nerves can branch 5% to 7% of the time above the level of the tarsal tunnel. The medial and lateral plantar nerves enter the plantar foot by passing deep to the abductor hallucis muscle below the level of the tarsal tunnel. The calcaneal nerve branches 35% of the time above the level of the tarsal tunnel, 34% of the time within the tunnel, and 16% to 25% of time from the lateral plantar nerve.35 It is important to consider all variations of the tibial nerve.

Nerve Injury

Seddon and Sunderland are the commonly utilized classification for nerve injuries. It is essential to understand what degree of nerve injury is present in a patient prior to surgical intervention.68

First Degree

Neuropraxia is the result of pressure, compressive trauma, entrapment, or contusion. The nerve conduction study will show decreased nerve conduction velocity and normal amplitudes past the zone of injury. The myelin is damaged, but axons are intact.

Second Degree

Axonotmesis is usually caused by traction injuries as seen in severe joint dislocations and intraneural neuromas. In a second-degree injury there is axonal discontinuity and Wallerian degeneration. The endoneurium, perineurium, and epineurium remain intact, but the axons are damaged. The nerve conduction study shows decreased nerve conduction velocity and absent amplitude.

Third Degree

A third-degree injury includes second-degree injury plus endoneurium disruption.

Fourth Degree

Figure 20.1 Tibial nerve neuroma incontinuity approximately 4 cm in length to medial aspect of lower extremity.(Photograph courtesy of Dr. Edgardo Rodriguez-Collazo, all rights reserved.)

Fifth Degree

Etiology of Recurrent Tarsal Tunnel Syndrome

There are 5 major etiologies that patients with recurrent tarsal tunnel symptoms fall under: incorrect diagnosis, an incomplete neurolysis or decompression, adhesive neuritis, intraneural damage, and double crush syndromes.1,9

Incorrect Initial Diagnosis

After a failed tarsal tunnel surgery, it is possible that initially the wrong diagnosis was made. Differential diagnosis of tarsal tunnel syndrome includes, but is not limited to, space-occupying lesions, underlying mechanical components, posterior tibial tendon dysfunction, hypertrophic or accessory muscles, and proliferative synovitis.1

Space-Occupying Lesions

Venous Varicosities

Tarsal tunnel syndrome can be caused by varicose vascular structures, and patients who have this syndrome may show characteristic symptoms. If varicose veins are in the tarsal tunnel and if a foot deformity is present, a diagnosis of tarsal tunnel syndrome due to varicose vascular structures compression should be considered.10

Clinical Pearl

Kumai et al. reported that patients suddenly feel foot pain whenever they soak a foot in hot water. This specific symptom occurs because of dilatation of the varicose vascular structures in the tarsal tunnel.11

Ganglion Cyst

Tarsal tunnel ganglia arise from the adjacent joints or tendon sheaths and compress the tibial nerve. Ganglia are the cause of tarsal tunnel syndrome in up to 8% of cases.12,13


A lipoma is a benign tumor composed of fatty tissue.

Nerve Tumors

Schwannomas are rare, benign tumors originating in the Schwann cells of the peripheral nervous system. Although presentation is rare in the foot and ankle, the posterior tibial nerve is the most common nerve affected.14 Plexiform neurofibromas are rare in the foot and ankle but have been reported. This benign nerve tumor arises as a diffuse mass from the nerve trunk and causes overgrowth of cutis and subcutis structures.15

Hypertrophic or Accessory Muscles

Hypertrophy of the abductor hallucis muscle is a rare condition but is present several times within the literature. Although the accessory soleus resides outside the tarsal tunnel, it has been implicated in tarsal tunnel syndrome, likely related to extrinsic compression.16

Proliferative Synovitis

Inflammation of the synovial membrane, or proliferative synovitis, can cause compression of the tibial nerve.1

Underlying Mechanical Component

Underlying rearfoot and ankle deformities can potentiate tarsal tunnel syndrome. A hindfoot valgus deformity may potentiate the symptoms of tarsal tunnel syndrome because the deformity may increase tension owing to an increase in eversion and dorsiflexion.1,17 It is therefore on high suspicion in the patient with significant flatfoot.

An Incomplete Release

Recurrent tarsal tunnel syndrome can occur when the entire nerve is not exposed at the area of entrapment or the fibrous tunnel and surrounding soft tissue is not properly decompressed. Owing to anatomic variations, a thorough understanding of the topography of the tibial nerve is crucial.1,9 The tibial nerve and its terminal branches are most commonly entrapped in the tarsal tunnel flexor retinaculum, but other sites of entrapment include abductor hallucis muscle canal/porta pedis, upper level of the medial malleolus, and proximal tibial nerve entrapment at soleal sling. More proximal entrapments of the lower extremity that are not addressed can cause residual tarsal tunnel-like symptoms. These entrapment sites are further discussed later in this chapter.1820

Adhesive Neuritis

External scarring around the previously released nerve can limit the gliding of the nerve, which leads to neuritic pain and recurrent entrapment. Adhesive neuritis can occur secondary to postoperative hemorrhage and hematoma formation, infection, prolonged swelling, delayed wound healing, and hypertrophic and keloid scarring. Patient noncompliance can also contribute to adhesive neuritis.1,9

Nerve “tethering” in the surgical scar is a main cause of perineural fibrosis pain; it reduces nerve gliding, which is necessary for nerve function, and interferes with intraneural microcirculation leading to neural ischemia and degeneration. These damaging conditions lead to further compression, neurogenic pain, and possible neuroma formation.2125

Clinical Pearl1,9

Intraneural Damage

Table 20.1

Mechanism of Injury and Injury Examples That Can Lead to Intraneural Damage

Mechanism of Injury Examples
Traction Ankle sprain, fracture, and dislocation/subluxation
Crush Compartment syndrome
Ischemia Can occur from extrinsic compression or vascular disease
Systemic disease Double crush syndromes, diabetes mellitus
Biomechanical Changes to tarsal tunnel volume due to hindfoot position
Pharmacologic Chemotherapy, radiation

Clinical Pearl

Double Crush Syndrome

Double crush syndrome can occur when there is a proximal and a distal nerve entrapment, whether by neuronal injury, compression, tension, or systemic disease.1 With double crush syndrome, each site of compression may not individually cause neuralgia, but the 2 sites of compression or the “double crush” together produce symptoms. Examples of double crush syndromes are radiculopathy, lumbosacral plexopathy, higher levels of compression in lower extremity such as at soleal sling, and systemic diseases (diabetes mellitus, hypothyroidism, multiple sclerosis, human immunodeficiency virus, Lyme disease, etc).1,9

History, Physical Examination, and Diagnostics

It can be overwhelming treating a patient with tibial nerve palsy, or recurrent symptoms, after a failed tarsal tunnel surgery. A patient with a history of failed tarsal tunnel surgery presents in 1 of 3 ways: no improvement after surgery, partial improvement, or temporary relief with recurrence of symptoms. Determining the initial and current presentation of the patient is the first step in treating the patient correctly. Once the surgeon understands the underlying etiology of the failed tarsal tunnel surgery and how patients present themselves, we can correlate these together to form the correct diagnosis.1,9 Below is a chart with patient presentation and which etiology you may expect (Table 20.2).1,9 When performing revisional procedures, the surgeon must take into account the “zone of injury,” or the area where the soft tissue is damaged. This can be divided into 2 categories: nonreconstructable and reconstructable (Table 20.3 and Figure 20.2).

Table 20.2

Typical Patient Presentation and List of Each Possible Etiology

No Improvement After Surgery Partial Improvement Temporary Relief With Recurrence of Symptoms
Incorrect initial diagnosis Incomplete release Adhesive neuritis
Intraneural damage Adhesive neuritis Other idiopathic causes
Double crush syndrome Intraneural damage

Double crush syndrome

Table 20.3

Description of Reconstructable and Nonreconstructable Zone of Injury

Reconstructable Zone of Injury Non-reconstructable Zone of Injury
Adequate blood flow Poor blood flow
Vascularized nerve bed Devascularized nerve bed
Adequate skin tissue envelope Poor skin tissue envelope

Figure 20.2 Example of nonreconstructable zone of injury: distal medial aspect of left lower extremity showing poor skin tissue envelope and circled areas of tibial nerve injury.(Photograph courtesy of Dr. Edgardo Rodriguez-Collazo, all rights reserved.)

History and Physical Examination

The history of the nature and quality of pain should be the first line of questions followed by the onset and progression. History of presentation is very important in the diagnosis of tibial nerve entrapment, or injury, and the literature shows that 43% of patients who have tibial nerve palsy have a history of trauma including events such as ankle sprains.5 Physical examination should include a dermatological, vascular, and musculoskeletal examination. Musculoskeletal examination is essential to determine if motor function has been affected and for biomechanical evaluation. A thorough neurological examination including Semmes-Weinstein monofilament, 2-point discrimination, sharp-dull sensation, presence of Tinel sign, and point of maximum tenderness should be performed.

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Oct 22, 2022 | Posted by in ORTHOPEDIC | Comments Off on Revisional Tarsal Tunnel Surgery
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