Case 29 – Not Sural Be Climbing This Weekend

33 yo male advanced climber

After a climbing session was experiencing tightness in calves bilaterally.

Patient had been using a theragun for treatment.   On this particular day, he was aggressively applying the theragun to to the left posterior lateral leg (middle third).

Patient presented 3 months after reported date of injury.

See figure 1

The patient felt a sudden sharp tearing feeling of pain in posterior calf. He felt paraesthesias into the lateral distal left leg and lateral foot constantly for the first week.

He felt the pain specifically with performing a Cossack stretch (Figure 2)

Figure 2 – Cossack Stretch from https://www.rehabhero.ca/exercise/cossack-squat

After the first week, the patient regularly experienced shock like sensations and paraesthesias into the lateral distal left leg and into dorsum of 4^th and 5^th metatarsal of his foot (see figure 3).

This was followed by on/off with stretching, initially with minimal stretching.

At 5 months, the patient continued to have a positive tinel’s at the lateral distal 1/3 calf.

Figure 3 – Distribution of described paraesthesias

No abnormalities in gait

Pulses were equal bilaterally

Colour was equal bilaterally

There was a postive tinel’s at the location of where the theragun was applied at 3 and 5 months.

The paraesthesias were also brought on by slump testing (including dorsiflexion of affected foot) and Cossack stretching

Neurologically power, sensation and reflexes were otherwise intact.

This is a rare neuropraxial injury involving the sural nerve secondary to a theragun. The symptoms fully abated in this patient in 5 1/2 months without treatment and avoiding further massage treatments.  Clinically the symptoms are sensory and can be brought on with slump testing with dorsiflexion of the ankle as well as a tinel’s over the midportion of the posterolateral calf (Dilworth, 2021).  The distribution of the sural nerve can be seen in Figure 4 – Sural nerve superimposed on skin

And the sural dermatome can be seen in Figure 5.

Figure 4 – Sural Nerve Superimposed on Surface anatomy

Figure 5 Sural nerve dermatome

Conservative treatment should suffice in majority of patients with the prognosis being > 3 months for resolve.  However if symptoms not improving after 3 months, would recommend an MRI of leg to check for signs of entrapment such as underlying hematoma, baker’s cyst, or osteochondroma from adjacent bone.     The sural nerve itself is purely sensory.  Another potential treatment option is a hydroneurolysis (aka hydrodissection) procedure.  This can be done by a physiatrist, who using ultrasound can inject the nerve sheath with either saline or lidocaine to free up the nerve from surrounding tissue irritation. (Omodani and Takahashi, 2023)  Cortisone can be added to this procedure.

Surgery has been described to resect hematomas that could cause a neuropraxial injury (Richardson et al., 2015), as well as cases of entrapment(Dilworth, 2021, Bryan et al., 1999).

Dr. Neil Dilworth, Juan Carlos Hernandez (2024/2/19 – PR MC )

Dilworth, N – Sural Nerve Entrapment. https://sportmedschool.com/sural-nerve-entrapment/ 2021.

Bryan BM 3rd, Lutz GE, O’Brien SJ. Sural nerve entrapment after injury to the gastrocnemius: a case report. Arch Phys Med Rehabil. 1999 May;80(5):604-6. doi: 10.1016/s0003-9993(99)90206-x. PMID: 10326928.

Omodani T, Takahashi K. Ultrasound-Guided Hydrodissection for Sural Neuropathy After Calcaneus Fracture Surgery: A Case Report. Cureus. 2023 Oct 26;15(10):e47749. doi: 10.7759/cureus.47749. PMID: 38022034; PMCID: PMC10676283.