Surgeons often encounter diagnostic challenges when treating a sural intraneural ganglion cyst. These mucinous lesions develop within the nerve sheath, usually originating from a nearby joint. According to the articular theory, synovial fluid tracks from a joint into the parent nerve through a specific articular branch. However, identifying this connection in the sural nerve is frequently difficult due to its unique anatomy. Therefore, recent surgical advancements suggest using specialized dyes to improve visualization.

Innovative Detection of a Sural Intraneural Ganglion Cyst

A 60-year-old woman recently presented with lateral foot pain and numbness. Additionally, clinicians noted a palpable mass along the sural nerve distribution. Preoperative MRI confirmed a large cyst with a clear connection to the subtalar joint. To ensure precise treatment, the surgical team performed a preoperative intra-articular fluorescein injection into the joint. Consequently, they could identify the articular branch intraoperatively using ultraviolet illumination.

During the procedure, the surgeon transected the connection at its joint origin. Furthermore, the team decompressed the cyst while carefully preserving the parent nerve. This targeted approach led to excellent clinical outcomes. Postoperatively, the patient experienced complete pain relief and full sensory recovery. Most importantly, follow-up MRI at eight months confirmed the total resolution of the cyst.

In conclusion, this case demonstrates that sural IGCs strictly follow the articular theory. Using fluorescein provides a reliable tool for detecting elusive articular branches. By addressing the joint source directly, surgeons can prevent recurrence and improve patient recovery.

How does the articular theory explain a sural intraneural ganglion cyst?

The theory posits that synovial fluid escapes from a degenerative joint through a capsular rent. This fluid then travels along the articular nerve branch, eventually forming a cyst within the parent nerve epineurium.

What are the benefits of using fluorescein in nerve surgery?

Fluorescein acts as a visual marker that highlights the path of synovial fluid. When used under ultraviolet light, it allows surgeons to pinpoint tiny articular branches that are otherwise nearly invisible to the naked eye.

Why is identifying the joint connection critical?

Failure to identify and transect the articular branch often leads to high recurrence rates. Directly addressing the joint source ensures the fluid pathway is closed, allowing the nerve to heal without the risk of the cyst returning.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice or a professional relationship. Refer to the latest local and national guidelines for clinical practice.

References

Gogoi R et al. Preoperative intra-articular fluorescein injection to detect the articular branch at surgery on a sural intraneural ganglion cyst at the ankle: illustrative case. J Neurosurg Case Lessons. 2026 Mar 09. doi: undefined. PMID: 41802287.

Texakalidis P, et al. What's new with intraneural ganglion cysts? World Neurosurgery. 2026 Jan 03. doi: 10.1016/j.wneu.2025.124765. PMID: 41475455.

Spinner RJ, et al. The articular theory for the pathogenesis of intraneural ganglion cysts: an unifying concept. J Neurosurg. 2003;99(2):330-343. doi: 10.3171/jns.2003.99.2.0330.