title: Local injection of autologous bone marrow cells to regenerate muscle in patients with traumatic brachial plexus injury: a pilot study.
abstract: OBJECTIVE
  Traumatic brachial plexus injury causes severe functional impairment of the arm. Elbow flexion is often affected. Nerve surgery or tendon transfers provide the only means to obtain improved elbow flexion. Unfortunately, the functionality of the arm often remains insufficient. Stem cell therapy could potentially improve muscle strength and avoid muscle-tendon transfer. This pilot study assesses the safety and regenerative potential of autologous bone marrow-derived mononuclear cell injection in partially denervated biceps.
  
  
  METHODS
  Nine brachial plexus patients with insufficient elbow flexion (i.e., partial denervation) received intramuscular escalating doses of autologous bone marrow-derived mononuclear cells, combined with tendon transfers. Effect parameters included biceps biopsies, motor unit analysis on needle electromyography and computerised muscle tomography, before and after cell therapy.
  
  
  RESULTS
  No adverse effects in vital signs, bone marrow aspiration sites, injection sites, or surgical wound were seen. After cell therapy there was a 52% decrease in muscle fibrosis (p = 0.01), an 80% increase in myofibre diameter (p = 0.007), a 50% increase in satellite cells (p = 0.045) and an 83% increase in capillary-to-myofibre ratio (p < 0.001) was shown. CT analysis demonstrated a 48% decrease in mean muscle density (p = 0.009). Motor unit analysis showed a mean increase of 36% in motor unit amplitude (p = 0.045), 22% increase in duration (p = 0.005) and 29% increase in number of phases (p = 0.002).
  
  
  CONCLUSIONS
  Mononuclear cell injection in partly denervated muscle of brachial plexus patients is safe. The results suggest enhanced muscle reinnervation and regeneration. Cite this article: Bone Joint Res 2014;3:38-47.
authors.affiliation: Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Hogendoorn
authors.forename: B J
authors.initials: BJ
authors.lastname: Duijnisveld
authors.forename: S G
authors.initials: SG
authors.lastname: van Duinen
authors.forename: B C
authors.initials: BC
authors.lastname: Stoel
authors.forename: J G
authors.initials: JG
authors.lastname: van Dijk
authors.forename: W E
authors.initials: WE
authors.lastname: Fibbe
authors.forename: R G H H
authors.initials: RG
authors.lastname: Nelissen
keywords: Autologous bone marrow injection; Brachial plexus; Partial muscle denervation