Novel minimally invasive surgery shows efficacy for treating lumbar spondylolysis

The mean preoperative VAS score improved 79 points after patients underwent the procedure.

Using the pedicle-hook-and-rod method with a percutaneous pedicle screw to treat young adult patients with lumbar spondylolysis may lead to a significant reduction in low-back pain, according to investigators in Japan.

“The spondylolytic patients who need the direct repair surgery are mostly young and very active, and sometimes sports players,” Koichi Sairyo, MD, and Toshinori Sakai, MD, co-authors of the study told Orthopedics Today. “Therefore, damage to the muscle by surgery should be minimal. Thus, this technique is efficient.” Sairyo and Sakai presented their research in a poster at the 36th Annual Meeting of the International Society of the Study of the Lumbar Spine (ISSLS).

However, Orthopedics Today Spine Section Editor, Scott D. Boden, MD, noted the need for a larger, comparative study on the technique.

“It is a small study on an interesting technique,” Boden told Orthopedics Today. “There is no real direct comparison group. This is always the challenge with minimally invasive surgical techniques. Once there is proof of concept, they require a more rigorous comparison with current alternatives.”

The technique

Sairyo and his colleagues from the University of Tokushima studied 10 patients with bilateral L5 spondylolysis who were treated using the pedicle-hook-and-rod (PSHR) method with a percutaneous pedicle screw.

“The skin incision becomes minimal [with this technique], so that the separation of paravertebral muscle becomes minimal,” Sairyo said.

During the minimally invasive procedure, surgeons make a 3-cm midline incision and separate the paravertebral muscles from the lamina. After confirming the defect, they remove the fibrocartilage mass from the area. The surgeons create 2-cm longitudinal incisions on both sides of the midline incision at 5 cm laterally and percutaneously insert the pedicle screws. Using the same lateral incisions, they harvest cancellous bone from the iliac crest. After inserting the screws, they attach the hook to the lamina and the rods are inserted into the pedicle screw holes. Finally, they pack the bone grafts into the defects.

Improvements

Sairyo and his colleagues found that the patients’ mean Japanese Orthopedic Association score improved from 15 points preoperatively to 26.4 points postoperatively. They also discovered that the mean preoperative visual analog score rose from 82 points preoperatively to 3 postoperatively. In addition, they found that all patients had a decrease in low back pain soon after the operation. They also discovered bone healing in all six patients who had more than 6-months follow-up. Overall, the investigators found no complications in the study group.

“If surgeons are doing percutaneous pedicle screw insertion for segmental fusion, they will not have such a learning curve,” Sairyo said. “It is not difficult.”

He noted that achieving bony healing is the most challenging part of the procedure.

“Combined usage of BMPs is the next step, because the union is the most important part,” Sairyo said.

For more information:

• Scott D. Boden, MD, is director of Emory University Spine Center. He can be reached at 59 Executive Park South, Suite 3000, Atlanta, GA 30329; 404-778-7143; e-mail: scott.boden@emoryhealthcare.org. He is a consultant to Medtronic, receives royalties from Medtronic and Osteotech, and his center receives various funding from Medtronic, Synthes, National Institutes of Health, Linvatec, Johnson & Johnson, DePuy, a Johnson & Johnson company, and Wright Medical Technology.
• Koichi Sairyo, MD, PhD, can be reached at the Department of Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School 3-18-15, Kuramoto, Tokushima 770-8503, Japan; E-mail: sairyokun@hotmail.com or Sairyo@clin.med.tokushima-u.ac.jp. He has no direct financial interest in any products or companies mentioned in this article.

Reference:

Sakai T, Sairyo K, Yasui N. Less invasive direct repair surgery for lumbar spondylolysis in young adults using percutaneous pedicle screw hook rod system. Poster #52. Presented at the 36th Annual Meeting of the International Society of the Study of the Lumbar Spine. May 4-8, 2009. Miami.