Smiley Face Rod Surgery: Procedure and Benefits

The smiley face rod surgery is performed under general anesthesia, with the patient placed in a prone position. A small incision is made along the midline, and the surgical team carefully exposes the affected vertebra. The defect in the pars interarticularis is cleaned, and pedicle screws are placed in the affected vertebra. A V-shaped rod is then secured against the spinous process, providing stability without rigid fixation.

Benefits of the smiley face rod technique include:

Reduced Surgical Complexity: Compared to traditional methods, the procedure is technically simpler and can be performed with minimal disruption to surrounding tissues.
Early Mobilization: Patients are allowed to resume activities shortly after surgery, which is particularly beneficial for young individuals.
Satisfactory Outcomes: Studies show that patients experience significant improvements in pain and disability scores postoperatively, maintaining these benefits over the long term.

In a retrospective analysis of 45 young patients who underwent smiley face rod surgery, significant improvements were observed in Visual Analog Scale (VAS) scores and Oswestry Disability Index (ODI) scores within three months post-surgery. These improvements were sustained throughout the follow-up period, averaging 11.2 years.

Clinical Outcomes and Recovery After Surgery

Clinical outcomes following smiley face rod surgery are generally favorable. Patients report substantial reductions in pain and improved functionality postoperatively. In the aforementioned study, VAS scores decreased from an average of 7.4 ± 1.5 preoperatively to 1.5 ± 0.6 three months after surgery, indicating significant pain relief. The ODI scores showed a similar trend, with scores dropping from 47.9 ± 10.3 preoperatively to 8.9 ± 1.2 at the three-month follow-up.

Despite a healing rate of 57.5% at 12 months, clinical outcomes remained excellent across all patients, regardless of whether the spondylolysis had healed. This suggests that the stabilization provided by the smiley face rod is sufficient to yield positive clinical outcomes, even in the absence of complete bony union.

Table 2: Clinical Outcomes Post-Surgery

Outcome Measure	Preoperative Score	3 Months Postoperative Score	Final Follow-up Score
VAS	7.4 ± 1.5	1.5 ± 0.6	1.5 ± 0.4
ODI	47.9 ± 10.3	8.9 ± 1.2	8.3 ± 1.4

Long-Term Healing Rates and Complications in Spondylolysis

The long-term healing rates associated with smiley face rod surgery present an intriguing aspect of patient recovery. With only 57.5% of patients achieving bone union within a year, it raises questions about the long-term implications of incomplete healing. Nonetheless, all patients reported satisfactory clinical outcomes, indicating that the surgery effectively alleviates symptoms, even if complete bony fusion is not achieved.

Complications associated with the smiley face rod technique are minimal. In the analyzed cohort, no significant medical or implant-related complications were reported during follow-up. One patient did undergo subsequent surgery for lumbar disc herniation at the adjacent segment, but this was unrelated to the initial spondylolysis surgery. This highlights the importance of ongoing monitoring for potential complications, particularly in young and active patients.

Table 3: Healing Rates and Complications

Healing Rate	Complications	Notes
57.5%	None	One patient required surgery for LDH

FAQ

What is spondylolysis?

Spondylolysis is a defect in the pars interarticularis of a vertebra, commonly seen in adolescents and young adults, often resulting from stress fractures.

How is spondylolysis treated?

Treatment options include conservative management with rest and physical therapy, and surgical intervention may be indicated for persistent symptoms.

What is the smiley face rod technique?

The smiley face rod technique is a surgical method used to stabilize the pars defect in spondylolysis, allowing for preservation of motion while providing necessary support.

What are the expected outcomes after smiley face rod surgery?

Patients typically experience significant pain relief and functional improvement, often maintaining these benefits over the long term despite variable healing rates.

Are there any complications associated with smiley face rod surgery?

Complications are minimal, and while some patients may develop issues like adjacent segment degeneration, most report satisfactory outcomes post-surgery.

References

Zhang, J., Liu, Y., & Zeng, Y. (2025). Late‐Onset Spinal Cord Dysfunction in Rigid Posttraumatic Thoracolumbar Kyphosis: Radiographic Analysis of Neurological Compromise. Orthopaedic Surgery
Lu, Y., Gao, S., Bai, M., Wang, Y., & Tian, Y. (2025). 3D‐Printed Laminae for Kyphosis in Ankylosing Spondylitis During Pedicle Subtraction Osteotomy. Orthopaedic Surgery
Kaufmann, R. A., Bosetti, A. A., Foster, B. K., & Baratz, M. E. (2025). Management of Severe Elbow Arthritis in a Young Patient. Journal of Hand Surgery Global Online. Retrieved from https://doi.org/10.1016/j.jhsg.2025.100736
Simion, G., & Eckardt, N. (2025). Hounsfield units as predictor for cage subsidence and loss of reduction: following posterior-anterior stabilization in thoracolumbar spine fractures. European Spine Journal
Zhang, Q., Chen, Z., Lin, Y., Qiu, J., & Wu, W. (2025). The long-term outcomes after smiley face rod surgery in young lumbar spondylolysis patients. Scientific Reports. Retrieved from https://doi.org/10.1038/s41598-025-04362-0
Finkelstein, M. (2025). Radiomics and machine learning for osteoporosis detection using abdominal computed tomography: a retrospective multicenter study. BMC Musculoskeletal Disorders. Retrieved from https://doi.org/10.1186/s12880-025-01743-9