The document discusses peripheral nerve injuries, specifically the tibial and peroneal nerves, detailing their anatomical functions, clinical implications of injuries, diagnostic methods, and treatment options. It highlights conditions such as tarsal tunnel syndrome and common peroneal neuropathy, including their causes, risk factors, symptoms, and differential diagnoses. A comprehensive approach involving history, physical examination, and imaging studies is emphasized for accurate diagnosis and evaluation.

1. PERIPHERAL NERVE INJURIES
Name: Naina Joshi
MPT 2nd year

2. Tibial nerve
• Nerve roots: L4-S3
• Sensory: Innervates the skin of the posterolateral leg, lateral foot and
the sole of the foot.
• Motor: Innervates the posterior compartment of the leg and the
majority of the intrinsic foot muscles.

5. Deep muscles of leg supplied by tibial nerve

6. Cutaneous Innervation to the sole of foot

7. Clinical Relevance
• Injury to the tibial nerve can cause motor loss and altered sensation and pain to
any of the areas it supplies, depending on site of involvement.
• Popliteal Fossa region. Injury may occur due to:
• Space occupying lesion
• Laceration injury
• Posterior dislocation of knee.
• Fractures of the tibia and fibula
• Local trauma to the posterior lower leg.

8. Medial malleolus level:
Compression of the tibial nerve in the osseofibrous tunnel below the flexor
retinaculum of the ankle causes tarsal tunnel syndrome. On examination it
presents as pain and paresthesia in the sole of the foot.

9. Tarsal Tunnel Syndrome
• Tarsal tunnel syndrome (TTS) is a compressive neuropathy of the
posterior tibial nerve.
• The tunnel lies posterior to the medial malleolus of the ankle, beneath
the flexor retinaculum.
• Symptoms include pain radiating into the foot, usually, this pain is
worsened by walking (or weight-bearing activities).

11. Etiology
• Tarsal tunnel syndrome is divided into intrinsic and extrinsic etiologies.
• Extrinsic causes include poorly fitting shoes, trauma, anatomic-biomechanical
abnormalities (tarsal coalition, valgus or varus hindfoot), post-surgical scarring,
systemic diseases, generalized lower extremity edema, diabetes, and post-surgical
scarring.
• Intrinsic causes include tendinopathy, tenosynovitis,osteophytes, hypertrophic
retinaculum, and space-occupying or mass effect lesions (enlarged or varicose
veins, ganglion cyst, lipoma, neoplasm, and neuroma).

12. Pathophysiology
• Up to 43% of patients have a history of trauma including events such
as ankle sprains. Abnormal biomechanics can contribute to disease
progression. Risk factors include systemic diseases such as diabetes
mellitus, hypothyroidism, gout, mucopolysaccharidosis, and
hyperlipidemia

13. History and Physical
• There is no specific test for the diagnosis of tarsal tunnel syndrome, and diagnosis is made with a detailed history and
clinical examination.
• Sharp shooting pain in the foot, numbness on the plantar surface, radiation of pain and paresthesias along the distribution of
the posterior tibial nerve, pain with extremes of dorsiflexion and eversion, and a tingling or burning sensation.
• The symptoms may worsen at night, with walking or standing, or after physical activity, and typically get better with rest.
• On exam, the provider may observe pes planus, pronated foot, or talipes equinovarus.
• In chronic cases, atrophy, weakness of the intrinsic foot muscles, and contractures of the toes may be appreciated. They are
typically tender on deep palpation of the tarsal tunnel.
• The gait should be analyzed for abnormalities including excessive pronation or supination, toe eversion, excessive foot
inversion or eversion, and antalgic gait.
• Light touch and two-point discrimination should be tested. The patient may have diminished plantar sensation in the
distribution of either the medial or lateral plantar nerve.
• Muscle strength and foot range of motion should be assessed.

14. • The five symptoms:Spontaneous pain or pain with movement,
• Burning pain
• Tinel sign
• Sensory disturbance
• Muscle atrophy or weakness

15. Evaluation
• Plain radiographs of the ankle and, possibly, the foot are the initial imaging study of choice. These may help
identify any structural abnormalities including osteophytes, hindfoot varus and valgus, tarsal coalition, or
evidence of previous trauma.
• Magnetic Resonance Imaging (MRI) is not sensitive for the diagnosis of the tarsal tunnel but may help
include or exclude other causes of the patient's symptoms.
• Electromyography (EMG) and nerve conduction studies (NCS) are frequently abnormal in patients with
tarsal tunnel syndrome.

16. Differential Diagnosis
• Achilles tendonitis
• Compartment syndrome of the deep flexor compartment
• Degenerative changes (calcaneal spurs, arthrosis of the joints of the foot)
• Inflammatory conditions of the ligaments and fascia of the foot and ankle.
• Intersection syndrome of the FHL and FDL at the knot of Henry
• L5 and S1 nerve root compression
• Morton metatarsalgia
• Neurogenic intermittent claudication
• Plantar fasciitis
• Polyneuropathy
• Retrocalcaneal bursitis

17. Peroneal nerve
• Also known as common fibular nerve.
• Nerve roots: L4 – S2
• Motor: Innervates the short head of the biceps femoris directly. Also
supplies (via branches) the muscles in the lateral and anterior
compartments of the leg.
• Sensory: Innervates the skin of the lateral leg and the dorsum of the
foot.

19. Cutaneous innervation of the leg

20. Etiology
• There have been numerous traumatic and atraumatic causes of peroneal nerve injury. Common causes of damage to the
peroneal nerve include the following:
• Trauma or injury to the knee: Knee dislocation..
• A direct impact, penetrating trauma, or laceration
• Fracture of the fibula, especially at the proximal fibula
• Anatomic risk factors: Common peroneal nerve entrapment can occur secondary to a fibrous band at the origin of the
peroneus longus
• External compression sources: Tight splint/cast
• Compression wrapping/bandage
• Habitual leg crossing
• Prolonged bed rest
• Peripheral nerve tumor

21. Epidemiology
• Common peroneal neuropathy is the commonest mononeuropathy
encountered in the lower limbs and the third most common focal
neuropathy encountered overall, after median (carpal tunnel
syndrome) and ulnar neuropathies.
• Traumatic injuries to the common peroneal nerve (CPN) most
commonly afflict young athletic patients (e.g., football, soccer) and
adult patients following high energy trauma (e.g., motor vehicle
collisions (MVCs)), with CPN injury reportedly occurring in 16 to
40% of patients following knee dislocations.

22. History and Physical
• A thorough history and physical exam to assess the status and function of the common peroneal
nerve is always required.
• The most common presentation of a common peroneal nerve injury is a weakness of ankle
dorsiflexion and the classic resultant foot drop or catching the toes while ambulating.
• There may also be accompanying numbness or paresthesia present along the lateral leg, dorsal foot,
and/or the first toe webspace. Pain may also be present in traumatic cases but is not always present.

23. Differential Diagnosis
• Peroneal tendon pathology
• Other compressive neuropathies: Tarsal tunnel syndrome
• Anterior tarsal tunnel syndrome
• Nonspecific tendinitis affecting lower limb muscles/tendons
• Chronic ankle pain