Long Island Peroneal Nerve Injury Lawyer

The common peroneal nerve — also called the common fibular nerve — is the most vulnerable major peripheral nerve in the lower extremity. It wraps around the head of the fibula at the outer aspect of the knee with minimal soft tissue protection, making it exceptionally susceptible to injury in car accidents involving lateral impact to the knee, fibular head fractures, or compartment syndrome. The characteristic result of common peroneal nerve injury is foot drop — the inability to lift the foot at the ankle — a functionally devastating condition that impairs walking, prevents running, and creates a permanent risk of tripping and falling.

Peroneal nerve injuries are classified by the Sunderland system based on the degree of damage to the nerve's internal architecture. Grade I neuropraxia (demyelination only) typically recovers fully within weeks. Grade V neurotmesis (complete nerve transection) requires surgical repair or nerve grafting, and permanent foot drop is the expected outcome without tendon transfer surgery. Grades II through IV represent intermediate injuries with variable recovery timelines measured in months to years, requiring serial EMG surveillance to document recovery or establish permanence.

Our Long Island personal injury attorneys have represented peroneal nerve injury victims for over 24 years, recovering substantial verdicts and settlements in cases involving all Sunderland grades of injury, surgical nerve repair, and tibialis posterior tendon transfer for permanent foot drop. We understand EMG electrodiagnosis, the Sunderland classification, and how to present nerve injury cases for their full legal value under New York law.

Peroneal Nerve Anatomy: Why It Is So Vulnerable at the Fibular Head

The common peroneal nerve (CPN) — formally named the common fibular nerve in current anatomical nomenclature — originates as the lateral division of the sciatic nerve in the posterior thigh. As it descends behind the knee, it winds around the lateral aspect of the fibular head, passing superficially through the fibular tunnel between the peroneus longus muscle and the fibular neck. At this point, the nerve is compressed between the bone of the fibular head and the overlying fibular tunnel — a location where it is palpable just beneath the skin with minimal soft tissue cushioning.

Below the fibular head, the common peroneal nerve divides into two terminal branches. The deep peroneal nerve descends through the anterior compartment of the lower leg, innervating the tibialis anterior (primary dorsiflexor of the foot), extensor hallucis longus (big toe extension), and extensor digitorum longus (toe extension), and providing sensory innervation to the first web space between the first and second toes. The superficial peroneal nerve descends through the lateral compartment, innervating the peroneus longus and peroneus brevis (foot eversion muscles) and providing sensory innervation to the dorsum (top surface) of the foot and ankle.

Importantly, the common peroneal nerve does not contribute to the ankle reflex — the deep tendon reflex at the Achilles tendon — which is mediated by the S1 nerve root through the tibial nerve. An absent ankle reflex in a patient with foot drop suggests lumbar nerve root pathology (S1 radiculopathy) rather than peroneal nerve injury at the fibular head, and is an important clinical distinction when evaluating causation.

Mechanisms of Peroneal Nerve Injury in Car Accidents

Clinical Presentation: Foot Drop and the Sunderland Classification

The clinical presentation of common peroneal nerve injury is characteristic and recognizable. The hallmark is foot drop — inability to dorsiflex the foot at the ankle, causing it to hang downward with gravity. Patients compensate with a steppage gait, lifting the entire leg high at the hip and knee during the swing phase of walking to clear the dragging foot from the ground. Weakness of foot eversion is an additional finding reflecting superficial peroneal nerve involvement. Sensory loss involves the dorsum of the foot (superficial peroneal distribution) and the first web space between the first and second toes (deep peroneal distribution), while the sole of the foot and the inner (medial) aspect of the ankle are spared.

A positive Tinel sign — reproduction of electric shock paresthesias radiating into the foot when the fibular head is tapped — indicates a site of nerve injury or regeneration at the fibular head and is a valuable clinical finding that localizes the injury level. Weakness testing should include dorsiflexion strength (tibialis anterior, graded 0 to 5), big toe extension strength (extensor hallucis longus), and foot eversion strength (peroneus longus and brevis); grading these on serial examinations is essential for tracking recovery.

Diagnosis: EMG, MRI Neurography, and Ultrasound

EMG and Nerve Conduction Velocity Testing

Electromyography (EMG) and nerve conduction velocity (NCV) testing are the primary electrodiagnostic tools for peroneal nerve injury evaluation. The optimal timing for initial EMG is 3 to 4 weeks after injury — before this point, wallerian degeneration is not complete and the study will underestimate the severity of axon loss. At 3 to 4 weeks, the EMG will reveal the presence of fibrillation potentials and positive sharp waves in the tibialis anterior, extensor hallucis longus, and peroneal muscles (indicating active denervation from axon loss), and NCV testing will demonstrate slowed or absent conduction velocity across the fibular head segment.

Serial EMG studies are essential for tracking the course of recovery and, critically, for documenting permanent denervation when recovery fails. Reinnervation potentials — nascent motor unit potentials with reduced amplitude and polyphasic morphology — appear in EMG at 3 to 4 months after injury when axonal regeneration reaches the muscle. Their absence at 12 months or beyond, combined with persistent fibrillation potentials in the affected muscles, documents the permanent denervation that establishes permanent consequential limitation under Section 5102(d).

MRI Neurography and High-Resolution Ultrasound

MRI neurography uses specialized pulse sequences to directly visualize the peroneal nerve anatomy and pathology. An injured nerve at the fibular head demonstrates T2 signal hyperintensity (increased brightness on fat-suppressed sequences) reflecting intraneural edema and axoplasmic stasis. MRI neurography can identify the precise level of nerve injury, characterize the extent of nerve involvement (complete versus partial), detect neuroma formation, and differentiate intrinsic nerve injury from extrinsic compression by hematoma or scar tissue.

High-resolution ultrasound of the fibular head region is a complementary and clinically practical tool that can be performed at the bedside. An injured peroneal nerve on ultrasound appears enlarged with decreased echogenicity (hypoechoic) at the injury site, reflecting intraneural edema and axonal disruption. Neuroma formation — a bulbous enlargement of the nerve at the injury site — is readily visible on ultrasound and indicates failed nerve repair that may benefit from surgical neurolysis. Ultrasound also allows dynamic evaluation during knee flexion and extension, revealing nerve subluxation over the fibular head — an additional injury pattern that can cause intermittent peroneal nerve symptoms.

Treatment: From Conservative Management to Tendon Transfer Surgery

Conservative Treatment for Grade I and Grade II Injuries

Grade I neuropraxia and Grade II axonotmesis injuries are initially managed conservatively. An ankle-foot orthosis (AFO) — a plastic brace worn in the shoe that holds the foot in a neutral dorsiflexed position — is fitted to prevent equinus contracture of the Achilles tendon during the period of foot drop and to allow safe walking during the recovery period. Physical therapy addresses ankle range-of-motion maintenance, progressive strengthening of recovering muscles, proprioceptive training, and gait normalization as dorsiflexion strength returns. Functional electrical stimulation (FES) devices that use surface electrodes over the peroneal nerve to stimulate dorsiflexion during the swing phase of walking can supplement AFO use and provide neuromuscular re-education.

Surgical Options for Grade III Through V Injuries

When no recovery is documented on serial EMG by 3 to 4 months after injury, or when imaging reveals a neuroma or structural nerve disruption at the fibular head, surgical exploration is indicated. Neurolysis — surgical decompression and release of scar tissue entrapping the nerve at the fibular head — is the least invasive surgical option and produces favorable results when performed within the first 3 to 6 months in cases where nerve continuity is maintained. Primary nerve repair is possible for sharp nerve lacerations with minimal gap; end-to-end neurorrhaphy under no tension can produce good functional recovery. For nerve gaps greater than 2 to 3 centimeters, nerve grafting using the sural nerve as an autograft is required. The sural nerve — a purely sensory nerve from the posterior lateral leg — is harvested and interposed between the proximal and distal nerve stumps to bridge the defect; recovery following sural nerve grafting is variable and typically incomplete for motor function.

Nerve transfer — using a redundant branch of the tibial nerve as a donor to reinnervate the deep peroneal nerve — is an alternative approach for proximal injuries where the distance from the injury site to the tibialis anterior is too great for reliable regeneration before muscle atrophy becomes irreversible.

Tibialis Posterior Tendon Transfer for Permanent Foot Drop

When nerve recovery has failed and permanent foot drop is established, tibialis posterior tendon transfer is the definitive reconstructive procedure. The tibialis posterior tendon — which normally inverts the foot from its insertion on the medial foot — is detached from its insertion, routed around the medial side of the tibia and through the interosseous membrane, and reattached to the dorsum of the foot at the extensor retinaculum or the base of the second and third metatarsals. This rerouting converts the tibialis posterior from a foot invertor to a dorsiflexor, restoring functional foot clearance during gait. Tibialis posterior tendon transfer is one of the most reliable and functionally meaningful procedures in reconstructive nerve surgery and can restore functional ambulation in patients with permanent peroneal nerve palsy, though the normal speed, power, and precision of dorsiflexion are not fully reproduced.

Peroneal Nerve Injury Case Results

Past results do not guarantee future outcomes. Each case is unique and depends on the specific facts, available insurance coverage, and extent of documented injury.

New York Law and Peroneal Nerve Injury Claims

Under New York Insurance Law Section 5102(d), peroneal nerve injuries satisfy the serious injury threshold under the "permanent consequential limitation of use of a body function or system" category when EMG testing demonstrates permanent denervation changes and a treating neurologist or physiatrist opines that no further nerve recovery is expected. Permanent foot drop — the inability to dorsiflex the foot documented by manual muscle testing and EMG electrodiagnostic evidence — constitutes a permanent consequential limitation of the lower extremity as a matter of law when properly documented.

Even partial foot drop satisfies the "significant limitation of use of a body function or system" category when documented consistently on serial objective examinations with quantified strength grades and supported by EMG evidence of ongoing or residual denervation. Neuropathic pain in the peroneal distribution — burning, electrical paresthesias along the dorsum of the foot and lateral leg — documented by the treating physician and corroborated by EMG findings also satisfies the significant limitation category. The 90 of 180 days category is readily satisfied given the extended AFO use, physical therapy, and activity restriction typical of all grades of peroneal nerve injury.

Our Long Island car accident lawyer team handles peroneal nerve injury cases with the neurological, electrodiagnostic, and peripheral nerve surgery expert resources these technically demanding claims require. We work with board-certified neurologists, physiatrists, and peripheral nerve surgeons to document the Sunderland grade of injury, the EMG evidence of denervation and recovery or its absence, and the functional limitations of foot drop for maximum recovery under New York law.

The statute of limitations for personal injury in New York is three years from the accident date under CPLR Section 214. No-fault insurance applications must be filed within 30 days. Contact us immediately after a peroneal nerve injury to preserve evidence, protect your no-fault rights, and ensure your EMG documentation begins at the optimal 3 to 4 week post-injury window.

Frequently Asked Questions — Peroneal Nerve Injury Cases