G57.0

Lesion of sciatic nerve

Lesion of the sciatic nerve (G57.0) is a peripheral mononeuropathy involving the body's largest nerve, which is formed by the spinal roots of L4 through S3. This condition involves focal damage or entrapment of the nerve along its anatomical course, most frequently at the level of the sciatic notch in the pelvis or within the posterior thigh. Sciatic neuropathy is clinically distinct from lumbar radiculopathy (compression at the spinal exit), although they may share similar pain distributions. Pathologically, the lesion may range from transient neuropraxia to permanent neurotmesis. It often presents with severe motor and sensory deficits because the sciatic nerve supplies the muscles of the posterior thigh and all muscles below the knee, as well as sensation to the majority of the lower leg and foot. Recognition of specific entrapment points, such as the piriformis muscle or the site of a previous hip arthroplasty, is critical for effective clinical management.

Clinical Symptoms

  • Sharp, burning, or stabbing pain originating in the gluteal region and radiating down the posterior thigh
  • Weakness in knee flexion (hamstring muscles)
  • Weakness in foot dorsiflexion and eversion (peroneal division involvement)
  • Weakness in plantar flexion and inversion (tibial division involvement)
  • Diminished or absent Achilles tendon reflex
  • Numbness or paresthesia in the lateral leg and the entire foot (sparing the medial malleolus)
  • Foot drop, leading to a steppage gait
  • Atrophy of the hamstring, calf, or intrinsic foot muscles in chronic cases
  • Dysesthesia or 'pins and needles' sensation exacerbated by prolonged sitting

Common Causes

  • Iatrogenic injury during total hip arthroplasty or pelvic surgery
  • Traumatic posterior hip dislocation
  • Pelvic or acetabular fractures
  • Piriformis syndrome (compression by the piriformis muscle)
  • Direct trauma, such as gunshot wounds or deep lacerations to the buttock or thigh
  • Complications from intramuscular injections in the gluteal region
  • Compression by pelvic masses, tumors, or hematomas
  • Endometriosis involving the sciatic nerve (catamenial sciatica)
  • Prolonged external pressure due to immobility or coma
  • Ischemic injury related to vasculitis or arterial occlusion

Documentation & Coding Tips

Explicitly document laterality for every encounter.

Example: Patient presents with chronic weakness in the right lower extremity. Physical exam reveals a positive Tinel sign at the sciatic notch on the right side. EMG testing confirms a right-sided sciatic nerve lesion. Diagnosis: Lesion of sciatic nerve, right lower limb (G57.01). Condition is chronic and currently managed with gabapentin, impacting the patient's gait and fall risk.

Billing Focus: Laterality (Right: G57.01, Left: G57.02, Bilateral: G57.03) is required for code specificity in the 2026 ICD-10-CM set.

Distinguish between a primary sciatic nerve lesion and lumbar radiculopathy.

Example: Evaluated patient for shooting leg pain. MRI of the lumbar spine shows no significant disc herniation or foraminal stenosis. Clinical findings demonstrate focal tenderness at the piriformis muscle and weakness in the distribution of the sciatic nerve distal to the hip. Diagnosis is G57.02 (Lesion of sciatic nerve, left lower limb), distinct from M54.16 (Lumbar radiculopathy).

Billing Focus: Clinicians must specify that the lesion is of the nerve trunk itself (G57.0) rather than a nerve root origin (M54.1- or M51.1-).

Document the specific etiology such as trauma, compression, or post-surgical complication.

Example: Patient is 3 months status-post right total hip arthroplasty. Presents with new-onset foot drop. Diagnostic studies confirm a right sciatic nerve lesion secondary to surgical positioning and compression. Diagnosis: G57.01 (Lesion of sciatic nerve, right lower limb) and Y83.1 (Surgical operation with implant of artificial internal device as the cause of abnormal reaction).

Billing Focus: Linking the lesion to a cause (e.g., trauma vs. compression) allows for the use of supplementary external cause codes.

Record the specific motor and sensory deficits identified during examination.

Example: Examination of the left lower limb reveals 3/5 strength in knee flexion and 2/5 in ankle dorsiflexion. Sensory loss is noted in the lateral calf and entire foot. These findings are consistent with a severe left sciatic nerve lesion at the level of the thigh. G57.02. Patient requires a dynamic AFO for gait stabilization.

Billing Focus: Documentation of functional deficits supports the medical necessity for CPT codes 95886 (EMG) and 97116 (Gait training).

Incorporate Electrodiagnostic (EDX) findings into the diagnostic statement.

Example: EDX study performed on 10/14/2025 demonstrates prolonged distal latencies and reduced amplitudes in the right sciatic nerve distribution, consistent with an incomplete lesion. No evidence of lumbosacral plexopathy. Diagnosis: G57.01, Lesion of sciatic nerve, right lower limb. Chronic neuropathic pain is managed with adjunct duloxetine.

Billing Focus: Mentioning EDX results provides the clinical gold standard proof required for high-level E/M and procedural billing.

Detail the clinical progression and episode of care for traumatic cases.

Example: Initial follow-up for a patient with a traumatic right sciatic nerve lesion sustained during a motor vehicle accident. Weakness persists but is showing slight improvement in the peroneal division. Continuing conservative management with physical therapy and gabapentin. G57.01 documented as the primary manifestation of the nerve injury during this subsequent encounter.

Billing Focus: Differentiates between acute traumatic injury (S74.0-) and the resulting chronic lesion (G57.0-).

Relevant CPT Codes

Related Diagnoses

Hierarchy