Cervical intervertebral disc allografting helped preserve spine motion, stability
AMSTERDAM — Results of a prospective pilot study of cervical intervertebral disc allograft transplantations performed in 24 patients indicate there were signs of bony endplate fusion and preserved neurological status at a maximum follow-up of 10 years, according to a study presented at SpineWeek 2012, here.
Di-Ke Ruan, MD, of the University of Hong Kong, presented his group’s findings at the meeting. He and colleagues previously published preliminary results for the first 5 patients in their series, all of whom underwent the grafting procedure for degenerative disc disease, he said.
“At 10 years follow-up, [the] allograft is able to survive in long-term follow-up with bridging across the end plate in a fusion,” Ruan said, noting the technique predates that of cervical total disc replacement (TDR), which he noted has been associated with variable results.
Ruan said the allograft donors were aged 20 years to 30 years, and most of them sustained and died from a trauma.
He and his colleagues typically harvested the allograft cervical discs within 6 hours to 8 hours post-mortem and preserved them in a nitrogen solution. They then implanted the allografts in patients enrolled in the study (average age 45 years) via a surgical technique Ruan described as similar to that used for fusion or TDR, which included both distraction and a decompression.
“Decompression is very important,” he said.
The investigators used a variety of outcome measures to assess results, such as the Japanese Orthopaedic Association score, Neck Disability Index, Visual Analog Scale and the SF-36, collecting results with them preoperatively and at 3, 6, 12 months and 5 years and 10 years after the transplantations. Because the transplanted discs were from young patients, the signals the researchers saw on follow-up MRIs were consistently good, Ruan said. Concerning motion preservation with the allograft surgery, in one case Ruan showed about 80% of the disc space was preserved.
“The motion at the 2-year follow up is about 9º degrees for flexion/extension, and then at 51 months flexion/extension is about 7º,” Ruan said.
That patient also maintained about 6.2º degrees flexion/extension motion at 10 years follow-up, he said.
- Ruan D-K, He Q, Ding Y, et al. Intervertebral disc allografts: A 10-year follow-up. Paper #68. Presented at SpineWeek 2012. May 28-June 1. Amsterdam.
- Ruan D, He Q, Ding Y, et al. Intervertebral disc transplantation in the treatment of degenerative spine disease: a preliminary study. Lancet. 2007;369:993-999.
- Disclosure: Ruan has no relevant financial disclosures.