Knee Pain Is Not Always the Knee.

Area of Science:

• Orthopedics
• Neurology
• Radiology

Background:

• Knee pain is common in older adults, often attributed to primary knee pathology.
• Lumbar spine conditions can cause referred pain to the lower extremities, mimicking knee pain.

Purpose of the Study:

• To highlight the significance of lumbar spine pathology as a differential diagnosis for knee pain in patients in their sixth decade.
• To emphasize the importance of spinal evaluation when knee imaging and examination findings are discordant.

Main Methods:

• Review of clinical presentations where lumbar pathology referred pain to the knee.
• Correlation of specific lumbar pathologies with referred knee pain symptoms.
• Identification of key neurological examination findings indicative of lumbar origin.

Main Results:

• Lumbar spine pathology is a frequent, yet often overlooked, cause of knee pain in older individuals.
• Lumbar (L) 3-4 disc herniation and spinal stenosis are the most prevalent spinal pathologies causing referred knee pain.
• Specific neurological signs like diminished patellar reflex, quadriceps weakness, and sensory loss point to L3-4 involvement.

Conclusions:

• Spinal pathology should be considered in the differential diagnosis of knee pain, especially in atraumatic cases in older patients.
• A comprehensive spine examination is crucial when knee radiographs do not correlate with clinical findings.
• Targeted assessment of neurological function can aid in diagnosing L3-4 referred knee pain.