Implantation of cauda equina nerve roots through a biodegradable scaffold at the conus medullaris in rat

Peter J. Grahn, Sandeep Vaishya, Andrew M. Knight, Bingkun K. Chen, Ann M. Schmeichel, Bradford L. Currier, Robert J. Spinner, Michael J. Yaszemski, Anthony J. Windebank

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Background context Traumatic injuries occurring at the conus medullaris of the spinal cord cause permanent damage both to the central nervous system and to the cauda equina nerve roots. Purpose This proof-of-concept study was to determine whether implanting the nerve roots into a biodegradable scaffold would improve regeneration after injury. Methods All experimental works involving rats were performed according to the approved guidelines by the Mayo Clinic Institutional Animal Care and Use Committee. Surgical procedures were performed on 32 Sprague-Dawley rats. Four ventral cauda equina nerve roots were reimplanted either directly into the ventral cord stump or through a poly(lactic-co-glycolic acid) (PLGA) scaffold. These experimental groups were compared with a control group in which the nerves were inserted into a muscle fascia barrier that was placed between the spinal cord and the nerve roots. Animals were sacrificed at 4 weeks. Results There was no difference in motor neuron counts in the spinal cord rostral to the injury in all treatment groups, implying equal potential for the regeneration into implanted nerve roots. One-way analysis of variance testing, with Tukey post hoc test, showed a statistically significant improvement in axon regeneration through the injury in the PLGA scaffold treatment group compared with the control (p<.05, scaffold n=11, control n=11). Conclusions This pilot study demonstrated that a PLGA scaffold improved regeneration of axons into peripheral nerve roots. However, the number of regenerating axons observed was limited and did not lead to functional recovery. Future experiments will employ a different scaffold material and possible growth factors or enzymes to increase axon populations.

Original languageEnglish (US)
Pages (from-to)2172-2177
Number of pages6
JournalSpine Journal
Issue number9
StatePublished - Sep 1 2014


  • Cauda equina
  • Conus medullaris
  • Nerve root avulsion
  • Neuroregeneration
  • PLGA scaffold
  • Spinal cord injury

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine
  • Clinical Neurology


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