1316 - The Incidence and Importance of Recognizing Conjoined Lumbosacral Nerve Roots for Interventions

Friday, February 20, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

KP

Kishan V. Patel, DO

Spine Medicine Fellow
Cleveland Clinic
cleveland, Ohio, United States

Co-Author(s)

JH

Jeffrey Hsia, MD

Resident Physician
Cleveland Clinic
Cleveland, Ohio, United States
ST

Santhosh Thomas, DO

Physician
Cleveland Clinic
Cleveland, Ohio, United States

Submitter(s)

KP

Kishan Patel, DO

Cleveland Clinic
cleveland, Ohio, United States

Case Diagnosis: 47-year-old female with chronic low back pain and conjoined right L5 and S1 spinal nerve roots.

Case Description: The patient presented with a year-long history of chronic low back and left-sided pelvic pain. After playing with her toddler, she went to stand and fell due to the pain, with loss of control of her bladder for a few hours. She had radiation of pain to her left hip and paresthesias to her dorsal toes. Rated pain 3/10 at rest and 10/10 with exertion. Left lumbar spine/hip range of motion and straight leg raise elicited pain. On follow-up, the patient’s pain radiation and paresthesias had improved, but she still had pelvic pain and was referred for physical therapy. MRI showed minimal multilevel bilateral foraminal and central stenosis with conjoint right L5-S1 nerve roots. No intervention was needed.

Discussions: Conjoined root anomalies are frequently confused with herniated discs on imaging. Coronal magnetic resonance imaging (MRI) offers the best means of visualizing a conjoined nerve root. Prevalence from retrospective cases during surgery ranges from 0.25 - 5.8%. Variants can be susceptible to injury from bulging discs or neuroforaminal stenosis due to their larger size and attachment to surrounding structures. Though historically diagnosed during surgery, advances with MRI have allowed earlier identification through recognition of signs such as craniocaudal elongation of the neural foramen and/or defects of the neural arch at the level of the conjoined nerves. If this anatomical variation is missed on imaging, interventional procedures and/or surgical management with nerve root mobilization could lead to treatment failure or neurologic injury.

Conclusions: Conjoint lumbosacral nerve roots are a rare, underdiagnosed embryological condition that can present technical challenges in treating patients with concomitant chronic low back pain. This case demonstrates that awareness is necessary before considering more invasive treatment options.