What is the appropriate diagnosis and management approach for an 8-year-old boy suspected of having tarsal tunnel syndrome?

Tarsal Tunnel Syndrome in Pediatric Patients

In an 8-year-old boy suspected of having tarsal tunnel syndrome, diagnosis relies primarily on clinical examination with a positive Tinel sign at the ankle, objective sensory loss along the tibial nerve distribution, and a positive dorsiflexion-eversion test, followed by conservative management including activity modification, orthoses, and physical therapy, with surgical decompression reserved only for cases with clear identification of the compressive cause and failure of conservative treatment after 3-6 months. 1, 2, 3

Clinical Diagnosis

Key Physical Examination Findings

• Tinel sign at the ankle is the most helpful diagnostic criterion, with tapping over the posterior tibial nerve behind the medial malleolus reproducing paresthesias in the foot 2, 3

• Dorsiflexion-eversion test should be performed by passively maximally everting and dorsiflexing the ankle while maximally dorsiflexing all metatarsophalangeal joints and holding for 5-10 seconds; this intensifies or induces symptoms in approximately 88% of confirmed cases 3

• Objective sensory loss along the distribution of the tibial nerve (plantar aspect of foot) must be documented 2

• Local tenderness over the tarsal tunnel beneath the flexor retinaculum is present in nearly all cases 3

Symptoms to Elicit in History

• Paresthesias, burning pain, or numbness in the plantar foot that may radiate proximally 1, 2

• Pain that worsens with activity and improves with rest 4

• Nocturnal symptoms are common 1

• In pediatric patients, complaints may be vague or described as "tired feet" or difficulty with prolonged walking 4

Diagnostic Testing

Electrodiagnostic Studies

• Nerve conduction studies (NCS) and electromyography (EMG) should be obtained to confirm the diagnosis, though no single test diagnoses TTS with certainty 1

• Abnormally slow nerve conduction through the posterior tibial nerve predicts failure of conservative treatment and may guide surgical decision-making 1

Imaging

• MRI of the ankle can identify space-occupying lesions, ganglion cysts, or anatomical variants causing compression 1

• Ultrasound may visualize nerve swelling or compressive masses 1

• Weight-bearing radiographs should be obtained to exclude osseous pathology such as tarsal coalition or accessory bones 5, 6

Critical Differential Diagnoses

The following must be systematically excluded:

• Plantar fasciitis: pain localized to plantar heel, worse with first steps in morning 1

• S1 radiculopathy: positive straight leg raise, dermatomal sensory loss extending above ankle 1

• Metatarsal stress fractures: point tenderness over metatarsal shafts, pain with hopping test 5, 6

• Morton's neuroma: pain between metatarsal heads, positive Mulder's click 1

• Anterior tarsal tunnel syndrome (deep peroneal nerve compression): pain and sensory changes on dorsum of foot between first and second toes, not plantar surface 7

Management Algorithm

Conservative Treatment (First-Line for 3-6 Months)

• Activity modification: reduce or eliminate aggravating activities, particularly repetitive impact 1, 4

• Orthoses: custom foot orthoses to correct excessive pronation or high arches, which are common biomechanical contributors in children 4

• Physical therapy: stretching of the flexor retinaculum, nerve gliding exercises, and strengthening of intrinsic foot muscles 1, 4

• NSAIDs: for pain control during acute exacerbations 4

• Corticosteroid injection: into the tarsal tunnel to reduce edema, though use cautiously in pediatric patients 1

Surgical Indications

Surgery should be considered only when:

• Conservative treatment fails after 3-6 months 1, 2

• Clear identification of the compressive cause is established (space-occupying lesion, anatomical variant, post-traumatic scarring) 1

• Abnormally slow nerve conduction is documented on electrodiagnostic studies 1

Surgical Technique

• Release of the flexor retinaculum from proximal attachment near medial malleolus down to the sustentaculum tali 1, 2

• Identification and removal of any compressive mass or causative factor 2

• Ultrasound-guided release is an emerging minimally invasive option 1, 4

Prognostic Factors

Predictors of Surgical Success

• Positive Tinel sign preoperatively is the strongest predictor of surgical relief 1

• Young age (favorable in pediatric patients) 1

• Short duration of symptoms before diagnosis 1

• Clear identifiable etiology 1

• No previous ankle pathology 1

Expected Outcomes

• Conservative management gives good results in the majority of cases 1

• Surgical success rates range from 44% to 96% when appropriate patient selection criteria are met 1

• Postoperative symptoms typically resolve within 2-3 months after surgery 3

Critical Pitfalls to Avoid

• Do not diagnose TTS based on symptoms alone; objective findings (positive Tinel, sensory loss, positive dorsiflexion-eversion test) must be present 2, 3

• Do not proceed to surgery without clear identification of the compressive cause, as idiopathic cases have poorer surgical outcomes 1, 2

• Do not rely solely on electrodiagnostic studies; diagnosis requires correlation of clinical history, physical examination, imaging, and NCS/EMG 1

• In pediatric patients, consider growth-related anatomical variants and biomechanical factors that may resolve with orthotic management alone 4

• Reexamine if initial conservative treatment fails at 6-8 weeks to reassess for alternative diagnoses or progression requiring surgical intervention 1